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Sample records for sandy sediments hosting

  1. Colonization dynamics of ciliate morphotypes modified by shifting sandy sediments.

    Science.gov (United States)

    Risse-Buhl, Ute; Felsmann, Katja; Mutz, Michael

    2014-08-01

    Sandy stream-bed sediments colonized by a diverse ciliate community are subject to various disturbance regimes. In microcosms, we investigated the effect of sediment shifting on the colonization dynamics of 3 ciliate morphotypes differing in morphology, behavior and feeding strategy. The dynamics of the ciliate morphotypes inhabiting sediment pore water and overlying water were observed at 3 sediment shifting frequencies: (1) stable sediments, (2) periodically shifting sediments such as migrating ripples, and (3) continuously shifting sediments as occurring during scour events of the uppermost sediment. Sediment shifting significantly affected the abundance and growth rate of the ciliate morphotypes. The free-swimming filter feeder Dexiostoma campylum was vulnerable to washout by sediment shifting since significantly higher numbers occurred in the overlying water than in pore water. Abundance of D. campylum only increased in pore water of stable sediments. On the contrary, the vagile grasper feeder Chilodonella uncinata and the sessile filter feeder Vorticella convallaria had positive growth rates and successfully colonized sediments that shifted periodically and continuously. Thus, the spatio-temporal pattern of sediment dynamics acts as an essential factor of impact on the structure, distribution and function of ciliate communities in sand-bed streams.

  2. The bioremediation potential of marine sandy sediment microbiota

    Directory of Open Access Journals (Sweden)

    Dan Răzvan POPOVICIU

    2012-11-01

    Full Text Available The natural microbiota from marine sandy sediments on the Romanian sea coast was tested for resilience in case of hydrocarbon contamination, for estimating the number of (culturable hydrocarbon and lipid oil-degrading microorganisms and for determining the influence of inorganic nitrate and phosphate nutrients on hydrocarbon spill bioremediation process, by microcosm experiments.Results show that hydrocarbon contamination affects the bacteriobenthos both in terms of cell numbers and composition. Bacterial numbers showed a rapid decrease (28% in four days, followed by a relatively fast recovery (two weeks. The pollution favoured the increase of Gram-positive bacterial proportion (from around 25% to 33%Sandy sediment microbiota in both sites studied contained microorganisms able to use mineral or lipid oils as sole carbon sources, usually around 103-104/cm3, with variations according to the sediment grain size and substrate used.The biostimulation experiments showed that, in absence of water dynamism (and, implicitly, an efficient oxygenation, the addition of nitrogen and phosphorus can be ineffective and even inhibit the remediation process, probably due to eutrophication.

  3. Glider observations and modeling of sediment transport in Hurricane Sandy

    Science.gov (United States)

    Miles, Travis; Seroka, Greg; Kohut, Josh; Schofield, Oscar; Glenn, Scott

    2015-03-01

    Regional sediment resuspension and transport are examined as Hurricane Sandy made landfall on the Mid-Atlantic Bight (MAB) in October 2012. A Teledyne-Webb Slocum glider, equipped with a Nortek Aquadopp current profiler, was deployed on the continental shelf ahead of the storm, and is used to validate sediment transport routines coupled to the Regional Ocean Modeling System (ROMS). The glider was deployed on 25 October, 5 days before Sandy made landfall in southern New Jersey (NJ) and flew along the 40 m isobath south of the Hudson Shelf Valley. We used optical and acoustic backscatter to compare with two modeled size classes along the glider track, 0.1 and 0.4 mm sand, respectively. Observations and modeling revealed full water column resuspension for both size classes for over 24 h during peak waves and currents, with transport oriented along-shelf toward the southwest. Regional model predictions showed over 3 cm of sediment eroded on the northern portion of the NJ shelf where waves and currents were the highest. As the storm passed and winds reversed from onshore to offshore on the southern portion of the domain waves and subsequently orbital velocities necessary for resuspension were reduced leading to over 3 cm of deposition across the entire shelf, just north of Delaware Bay. This study highlights the utility of gliders as a new asset in support of the development and verification of regional sediment resuspension and transport models, particularly during large tropical and extratropical cyclones when in situ data sets are not readily available.

  4. Influence of advective bio-irrigation on carbon and nitrogen cycling in sandy sediments

    OpenAIRE

    Na, T.; Gribsholt, B.; Galaktionov, O. S.; T. Lee; Meysman, F. J. R.

    2008-01-01

    In sandy sediments, the burrow ventilation activity of benthic macrofauna can generate substantial advective flows within the sediment surrounding their burrows. Here we investigated the effects of such advective bio-irrigation on carbon and nitrogen cycling in sandy sediments. To this end, we combined a range of complementary experimental and modelling approaches in a microcosm study of the lugworm Arenicola marina (Polychaeta: Annelida). Bio-irrigation rates were determined using uranine as...

  5. Sediment yield computation of the sandy and gritty area based on the digital watershed model

    Institute of Scientific and Technical Information of China (English)

    LIU; Jiahong; WANG; Guangqian; LI; Tiejian; XUE; Hai

    2006-01-01

    The Yellow River is well known as a sediment-laden river, which is the main reason that it cannot be controlled as easily as other rivers. Many researchers, such as Qian Ning et al., have found that the sediment load of the Yellow River comes mainly from the sandy and gritty area of the Loess Plateau. Therefore, it is very important to simulate the sediment yield in this area. This paper proposes a method to compute the sediment production in the sandy and gritty area based on the digital watershed model. The suggested model is calibrated and validated in the Chabagou basin, which is a small catchment in the study area. Finally, the model simulates the sediment yield of the sandy and gritty area in 1967, 1978, 1983, 1994 and 1997, which represents a high water and high sediment year, a mean water and mean sediment year, a high water and low sediment year, a low water and high sediment year, and a low water and low sediment year separately. The simulation results, including the runoff depth and erosion modulus, can well explain the "low water and high sediment" phenomena in the Yellow River basin. The total amount of the sediment production and its distribution generated by the model is very useful for water and soil conservation in the sandy and gritty area of the Loess Plateau.

  6. Dissolved and Bubble Gas Concentrations in Sandy Surficial Sediments of the West Florida Sand Sheet

    Science.gov (United States)

    2016-06-21

    Dissolved and Bubble Gas Concentrations in Sandy Surficial Sediments of the West Florida Sand Sheet Christopher Martens Dept. of Marine Sciences CB...TITLE AND SUBTITLE Dissolved and Bubble Gas Concentrations in Sandy Surficial Sediments of the West Florida Sand Sheet 5a. CONTRACT NUMBER 5b. GRANT...was noted that there was substantially higher organic material in the shallow troughs of the sand ripples than on the crests. Most of this appears

  7. Comparative study on microphytobenthic pigments of muddy and sandy intertidal sediments of the Tagus estuary

    NARCIS (Netherlands)

    Cartaxana, P; Mendes, CR; van Leeuwe, MA; Brotas, [No Value

    2006-01-01

    The abundance and distribution of microphytobenthic pigments determined by HPLC (chlorophylls and carotenoids) were compared between muddy and sandy sediments of the Tagus estuary (Portugal). In the two types of sediment, with similar periods of illuminated emersion, chlorophyll a concentrations on

  8. Comparative study on microphytobenthic pigments of muddy and sandy intertidal sediments of the Tagus estuary

    NARCIS (Netherlands)

    Cartaxana, P; Mendes, CR; van Leeuwe, MA; Brotas, [No Value

    2006-01-01

    The abundance and distribution of microphytobenthic pigments determined by HPLC (chlorophylls and carotenoids) were compared between muddy and sandy sediments of the Tagus estuary (Portugal). In the two types of sediment, with similar periods of illuminated emersion, chlorophyll a concentrations on

  9. Comparative study on microphytobenthic pigments of muddy and sandy intertidal sediments of the Tagus estuary

    Science.gov (United States)

    Cartaxana, P.; Mendes, C. R.; van Leeuwe, M. A.; Brotas, V.

    2006-01-01

    The abundance and distribution of microphytobenthic pigments determined by HPLC (chlorophylls and carotenoids) were compared between muddy and sandy sediments of the Tagus estuary (Portugal). In the two types of sediment, with similar periods of illuminated emersion, chlorophyll a concentrations on a per area basis (mg m -2) were comparable (down to 2 mm). Pigment analysis also revealed similar microphytobenthic communities in terms of algal classes. Diatoms were the dominant microalgae, but cyanophytes, euglenophytes and phanerogam debris were also present. For both muddy and sandy sediments, microphytobenthic biomass showed a high level of variability both within and between two consecutive years. Microphytobenthos was highly stratified in the mud, with most of the chlorophyll a occurring in the top 500 μm. In the sand, relatively constant concentrations were found throughout the sediment profile down to 3 mm. This is probably related to deeper light penetration in sandy sediment and/or increased physical mixing caused by invertebrate activity or overlying currents, leading to the burial of an important fraction of the microphytobenthic cells. Differences observed in the intensity of sediment coloration of muddy and sandy sediments might have resulted from the different vertical distribution of benthic biomass.

  10. Sediment Chemistry and Toxicity in Barnegat Bay, New Jersey: Pre- and Post- Hurricane Sandy, 2012-2013.

    Science.gov (United States)

    Romanok, Kristin; Szabo, Zoltan; Reilly, Timothy J.; Defne, Zafer; Ganju, Neil K.

    2016-01-01

    Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

  11. Sediment chemistry and toxicity in Barnegat Bay, New Jersey: Pre- and post-Hurricane Sandy, 2012-13.

    Science.gov (United States)

    Romanok, Kristin M; Szabo, Zoltan; Reilly, Timothy J; Defne, Zafer; Ganju, Neil K

    2016-06-30

    Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

  12. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    NARCIS (Netherlands)

    Bühring, S.I.; Ehrenhauss, S.; Kamp, A.; Moodley, L.; Prof. Witte, U.

    2006-01-01

    In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight (southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we

  13. Importance of phytodetritus and microphytobenthos for heterotrophs in a shallow subtidal sandy sediment

    NARCIS (Netherlands)

    Evrard, V.; Huettel, M.; Cook, P.L.M.; Soetaert, K.; Heip, C.H.R.; Middelburg, J.J.

    2012-01-01

    The relative importance of allochthonous phytodetritus deposition and autochthonous microphytobenthos (MPB) production for benthic consumers in an organic carbon (C-org)-poor sandy sediment was assessed using a C-13-stable isotope natural abundance study combined with a dual C-13-tracer addition app

  14. Microplastics elutriation from sandy sediments: A granulometric approach.

    Science.gov (United States)

    Kedzierski, Mikaël; Le Tilly, Véronique; Bourseau, Patrick; Bellegou, Hervé; César, Guy; Sire, Olivier; Bruzaud, Stéphane

    2016-06-15

    Although relatively easy to extract in the marine environment, microplastics are very difficult to recover when they are trapped in sediments. The elutriation column is one of the best tools currently available for extracting plastics from sediment, but with a high sand recovery yield. This study aims to address the following questions: (i) is it possible to use a sedimentological approach to limit the sand recovery? (ii) does the extraction velocity of the sand and plastic particles vary according to density and granulometry? (iii) what is the relative recovery efficiency obtained for dense polymer particles mixed with marine sand? Based on a new granulometric classification, different plastic particle-size fractions are defined. Their extraction velocities are experimentally determined on particles of sediment and different plastics (PA, PVC). The particle recovery experiments indicate that it is possible to extract >90% of dense plastic particles in cases of negligible sand recovery.

  15. Hydrodynamic Stresses Driving Pore Pressure Changes in Sandy Coastal Sediments

    Science.gov (United States)

    1997-09-30

    Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be...SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report (SAR) 18. NUMBER OF PAGES 2 19a. NAME OF RESPONSIBLE PERSON a. REPORT...nature of the sediment properties (Mei and Foda , 1981, Bennett et al. 1982, 1992a and b). A serious deficiency exist in the available in situ data bases

  16. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    DEFF Research Database (Denmark)

    Bühring, Solveig I.; Ehrenhauss, Sandra; Kamp, Anja

    2006-01-01

    investigated the pathway of settling particulate organic carbon through the benthic food web. The diatom Ditylum brightwellii was labelled with the stable carbon isotope 13C and injected into incubation chambers. On-board incubations lasted 12, 30 and 132 h, while the in situ experiment was incubated for 32 h......In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight (southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we....... The study revealed a stepwise short-term processing of a phytoplankton bloom settling on a sandy sediment. After the 12 h incubation, the largest fraction of recovered carbon was in the bacteria (62%), but after longer incubation times (30 and 32 h in situ) the macrofauna gained more importance (15 and 48...

  17. Experimental study on subharmonic and ultraharmonic acoustic waves in water-saturated sandy sediment.

    Science.gov (United States)

    Kim, Byoung-Nam; Lee, Kang Il; Yoon, Suk Wang

    2007-04-01

    Experimental observations of the subharmonic and ultraharmonic acoustic waves in water-saturated sandy sediment are reported in this paper. Acoustic pressures of both nonlinear acoustic waves strongly depend on the driving acoustic pressure at a transducer. The first ultraharmonic wave reaches a saturation value as the driving acoustic pressure increases. The acoustic pressure levels of both nonlinear acoustic waves exhibit some fluctuations in comparison with that of the primary acoustic wave as the receiving distance of hydrophone increases in sediment. The subharmonic and the ultraharmonic phenomena in this study show close resemblance to those produced in bubbly water.

  18. Groundwater recharge measurements in gravel sandy sediments with monolith lysimeter

    Science.gov (United States)

    Bracic Zeleznik, Branka; Souvent, Petra; Cencur Curk, Barbara; Zupanc, Vesna

    2013-04-01

    Ljubljana field aquifer is recharging through precipitation and the river Sava, which has the snow-rain flow regime. The sediments of the aquifer have high permeability and create fast flow as well as high regeneration of the dynamic reserves of the Ljubljana field groundwater resource. Groundwater recharge is vulnerable to climate change and it is very important for drinking water supply management. Water stored in the soil and less permeable layers is important for water availability under extreme weather conditions. Measurements of water percolation through the vadose zone provide important input for groundwater recharge assessment and estimation of contaminant migration from land surface to the groundwater. Knowledge of the processes governing groundwater recharge in the vadose zone is critical to understanding the overall hydrological cycle and quantifying the links between land uses and groundwater quantity and quality. To improve the knowledge on water balance for Ljubljana field aquifer we establish a lysimeter for measurements of processes in unsaturated zone in well field Kleče. The type of lysimeter is a scientific lysimeter designed to solve the water balance equation by measuring the mass of the lysimeter monolith as well as that of outflow tank with high accuracy and high temporal resolution. We evaluated short period data, however the chosen month demonstrates weather extremes of the local climate - relatively dry periods, followed by high precipitation amount. In time of high water usage of vegetation only subsequent substantial precipitation events directly results in water flow towards lower layers. At the same time, gravely layers of the deeper parts of the unsaturated zone have little or no capacity for water retention, and in the event that water line leaves top soil, water flow moves downwards fairly quickly. On one hand this confirms high recharge capacity of Ljubljana field aquifer from precipitation on green areas; on the other hand it

  19. First-Year Downstream Sediment Budget Following the Marmot Dam Removal from the Sandy River, Oregon

    Science.gov (United States)

    Podolak, C. J.; Wilcock, P. R.; Pittman, A.

    2008-12-01

    The October 2007 removal of the Marmot Dam, from the Sandy River, OR, provides an opportunity to assess the impact of increased sediment flux on a river channel. The Sandy River drains the west flank of Mt Hood and typically carries a large load of sand and gravel. The 14-meter-tall dam impounded over 750,000 m3 of sediment, only a small amount of which was removed during the decommissioning. Using a one- dimensional modeling approach, it was assessed that the river could transport the accumulated sediment without large adverse impacts downstream of the dam (Cui et al, 2008 - abstract submitted). In order to observe the actual changes to the river due to the dam removal and to test the modeled predictions, a significant monitoring effort has be in place on the Sandy River including bedload and suspended load measurements, discharge measurements, high-fidelity topographic surveys, repeat photography, multiple airborne LIDAR flights, long profile surveys, as well as mapping and characterizing the grain sizes throughout several reaches downstream of the dam. A key step in the quest to describe and predict the spatial distribution of the sediment throughout the downstream reach is to first account for all the sediment (both stored in the reservoir and supplied from upstream). Here, we examine the transport and deposition downstream of the dam through a 2-fraction sediment budget approach using the former dam as the upstream limit of the reach and choosing a the mouth of a bedrock gorge 7 km below the dam site as the downstream limit. Suspended sediment and bedload measurements taken by the USGS just below the dam site (Major et al, 2008 - abstract submitted) are combined with suspended sediment and bedload measurements collected just below the mouth of the gorge and the annual hydrograph to define the sediment fluxes into and out of the reach. Repeat surveys in the reach below the dam (Wallick et al, 2008 - abstract submitted) provide the measure of change in storage

  20. MORPHOLOGY OF METHANE HYDRATE HOST SEDIMENTS.

    Energy Technology Data Exchange (ETDEWEB)

    JONES,K.W.; FENG,H.; TOMOV,S.; WINTER,W.J.; EATON,M.; MAHAJAN,D.

    2004-12-01

    Results from simulated experiments in several laboratories show that host sediments influence hydrate formation in accord with known heterogeneity of host sediments at sites of gas hydrate occurrence (1). For example, in Mackenzie Delta, NWT Canada (Mallik 2L-38 well), coarser-grained units (pore-filling model) are found whereas in the Gulf of Mexico, the found hydrate samples do not appear to be lithologically controlled. We have initiated a systematic study of sediments, initially focusing on samples from various depths at a specific site, to establish a correlation with hydrate occurrence (or variations thereof) to establish differences in their microstructure, porosity, and other associated properties. The synchrotron computed microtomography (CMT) set-up at the X-27A tomography beam line at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory was used as a tool to study sediments from Blake Ridge at three sub bottom depths of 0.2, 50, and 667 meters. Results from the tomographic analysis of the deepest sample (667 m) are presented here to illustrate how tomography can be used to obtain new insights into the structures of methane hydrate host sediments. The investigation shows the internal grain/pore space resolution in the microstructure and a 3-D visualization of the connecting pathways obtained following data segmentation into pore space and grains within the sediment sample. The analysis gives the sample porosity, specific surface area, mean particle size, and tortuosity, as well. An earlier report on the experimental program has been given by Mahajan et al. (2).

  1. Comparison of wastewater-associated contaminants in the bed sediment of Hempstead Bay, New York, before and after Hurricane Sandy

    Science.gov (United States)

    Fisher, Shawn C.; Phillips, Patrick; Brownawell, Bruce J.; Browne, James

    2016-01-01

    Changes in bed sediment chemistry of Hempstead Bay (HB) have been evaluated in the wake of Hurricane Sandy, which resulted in the release of billions of liters of poorly-treated sewage into tributaries and channels throughout the bay. Surficial grab samples (top 5 cm) collected before and (or) after Hurricane Sandy from sixteen sites in HB were analyzed for 74 wastewater tracers and steroid hormones, and total organic carbon. Data from pre- and post-storm comparisons of the most frequently detected wastewater tracers and ratios of steroid hormone and of polycyclic aromatic hydrocarbon concentrations indicate an increased sewage signal near outfalls and downstream of where raw sewage was discharged. Median concentration of wastewater tracers decreased after the storm at sites further from outfalls. Overall, changes in sediment quality probably resulted from a combination of additional sewage inputs, sediment redistribution, and stormwater runoff in the days to weeks following Hurricane Sandy.

  2. A new method for measuring bioturbation rates in sandy tidal flat sediments based on luminescence dating

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, Andrew S.; jain, A

    2011-01-01

    The rates of post-depositional mixing by bioturbation have been investigated using Optically Stimulated Luminescence (OSL) dating in two sediment cores (BAL2 and BAL5), retrieved from a sandy tidal flat in the Danish part of the Wadden Sea. A high-resolution chronology, consisting of thirty-six OSL...... ages with ages ranging between 2 4 and 410 20 years, is presented. Slices of sediment (1e2 cm thick) have been dated at least every 5 cm, and from these data mixing depths of 20 cm and 22 cm (BAL5 and BAL2, respectively) are readily identified. Below the mixing zone there is a significant decrease....... The significant change in sedimentation rates at BAL5 may indicate an offset in OSL age of up to 620 years. This paper uses a simple conceptual model for vertical mixing in which all the sediment excreted at the surface by lugworms is assumed to be completely reset before being re-incorporated in the sediment...

  3. A new method for measuring bioturbation rates in sandy tidal flat sediments based on luminescence dating

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, Andrew S.; jain, A

    2011-01-01

    The rates of post-depositional mixing by bioturbation have been investigated using Optically Stimulated Luminescence (OSL) dating in two sediment cores (BAL2 and BAL5), retrieved from a sandy tidal flat in the Danish part of the Wadden Sea. A high-resolution chronology, consisting of thirty-six OSL...... ages with ages ranging between 2 4 and 410 20 years, is presented. Slices of sediment (1e2 cm thick) have been dated at least every 5 cm, and from these data mixing depths of 20 cm and 22 cm (BAL5 and BAL2, respectively) are readily identified. Below the mixing zone there is a significant decrease....... The significant change in sedimentation rates at BAL5 may indicate an offset in OSL age of up to 620 years. This paper uses a simple conceptual model for vertical mixing in which all the sediment excreted at the surface by lugworms is assumed to be completely reset before being re-incorporated in the sediment...

  4. A new method for measuring bioturbation rates in sandy tidal flat sediments based on luminescence dating

    DEFF Research Database (Denmark)

    Madsen, Anni T.; Murray, Andrew S.; Jain, Mayank

    2011-01-01

    The rates of post-depositional mixing by bioturbation have been investigated using Optically Stimulated Luminescence (OSL) dating in two sediment cores (BAL2 and BAL5), retrieved from a sandy tidal flat in the Danish part of the Wadden Sea. A high-resolution chronology, consisting of thirty-six OSL...... ages with ages ranging between 2 ± 4 and 410 ± 20 years, is presented. Slices of sediment (1–2 cm thick) have been dated at least every 5 cm, and from these data mixing depths of 20 cm and 22 cm (BAL5 and BAL2, respectively) are readily identified. Below the mixing zone there is a significant decrease....... The significant change in sedimentation rates at BAL5 may indicate an offset in OSL age of up to 620 years. This paper uses a simple conceptual model for vertical mixing in which all the sediment excreted at the surface by lugworms is assumed to be completely reset before being re-incorporated in the sediment...

  5. MOBILIZATION AND CHARACTERIZATION OF COLLOIDS GENERATED FROM CEMENT LEACHATES MOVING THROUGH A SRS SANDY SEDIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Roberts, K.; Kaplan, D.; Seaman, J.

    2011-09-20

    Naturally occurring mobile colloids are ubiquitous and are involved in many important processes in the subsurface zone. For example, colloid generation and subsequent mobilization represent a possible mechanism for the transport of contaminants including radionuclides in the subsurface environments. For colloid-facilitated transport to be significant, three criteria must be met: (1) colloids must be generated; (2) contaminants must associate with the colloids preferentially to the immobile solid phase (aquifer); and (3) colloids must be transported through the groundwater or in subsurface environments - once these colloids start moving they become 'mobile colloids'. Although some experimental investigations of particle release in natural porous media have been conducted, the detailed mechanisms of release and re-deposition of colloidal particles within natural porous media are poorly understood. Even though this vector of transport is known, the extent of its importance is not known yet. Colloid-facilitated transport of trace radionuclides has been observed in the field, thus demonstrating a possible radiological risk associated with the colloids. The objective of this study was to determine if cementitious leachate would promote the in situ mobilization of natural colloidal particles from a SRS sandy sediment. The intent was to determine whether cementitious surface or subsurface structure would create plumes that could produce conditions conducive to sediment dispersion and mobile colloid generation. Column studies were conducted and the cation chemistries of influents and effluents were analyzed by ICP-OES, while the mobilized colloids were characterized using XRD, SEM, EDX, PSD and Zeta potential. The mobilization mechanisms of colloids in a SRS sandy sediment by cement leachates were studied.

  6. Influences of microbial activity and sediment disturbance on hyporheic exchange in sandy sediments

    Science.gov (United States)

    Mendoza-Lera, C.; Mutz, M.

    2012-04-01

    Besides the vertical hydraulic gradient, sediment permeability is the main controlling factor of water exchange across the stream bed. Reduction of permeability by microbial activity is reported from unidirectional percolated sediment columns. We investigated effects of algal and bacterial activity on hyporheic exchange (vertical water flux, VWF) under semi-natural stream conditions in 16 outdoor sand-bed flumes during 30 day. Variability of bedform was considered by 8 flumes having plane-bed and 8 flumes ripple-bed. To gain information on the relative significance of algae and heterotrophic microorganisms, half of the flumes were operated under constant dark conditions (no-light flumes), while the others were exposed to daylight. After 21 days, the upper 2 cm of the sediments was manually disturbed simulating moderate sediment dynamics which frequently occurs in natural sand-bed streams. VWF was measured by tracing loss of uranine from the water column while flumes were operating in re-circulating mode. Algae and bacterial abundance, organic matter, and CaCO3 content in sediments were determined. Sediment potential respiration (SPR) was measured in flow through respiration chambers and oxygen bubbles from primary production were sampled. As expected, initial VWF was higher in ripple-bed. After 13 days, VWF was completely inhibited in both plane and ripple-bed flumes under daylight conditions. In no-light flumes reduction of VWF was moderate. Microbial precipitation of calcium carbonate and production of oxygen bubbles in the uppermost sediments blocked the pore space. After 3 weeks, abundance and biomass of algae and SPR in the upper 2 cm of sediment were higher in daylight flumes than in no-light flumes, while bacterial abundance was higher in no-light flumes. The sediment disturbance at day 21 released the oxygen bubbles increased bed permeability and therefore restored VWF to initial rates in day-light flumes. SPR was unaffected by the sediment disturbance. In

  7. Effects of deposition of heavy-metal-polluted harbor mud on microbial diversity and metal resistance in sandy marine sediments

    DEFF Research Database (Denmark)

    Toes, Ann-Charlotte M; Finke, Niko; Kuenen, J Gijs;

    2008-01-01

    Deposition of dredged harbor sediments in relatively undisturbed ecosystems is often considered a viable option for confinement of pollutants and possible natural attenuation. This study investigated the effects of deposition of heavy-metal-polluted sludge on the microbial diversity of sandy...

  8. A laboratory experiment of intact polar lipid degradation in sandy sediments

    Directory of Open Access Journals (Sweden)

    J. Logemann

    2011-03-01

    Full Text Available Intact polar lipids (IPLs are considered biomarkers for living biomass. Their degradation in marine sediments, however, is poorly understood and complicates interpretation of their occurrence in geological samples. To investigate the turnover of IPLs, a degradation experiment with anoxic sandy sediments from the North Sea was conducted. Intact cells of two organisms that do not naturally occur in North Sea sediments were chosen as IPL sources: (i Saccharomyces cerevisiae, representative for ester-bound acyl lipids that also occur in Bacteria, and (ii the archaeon Haloferax volcanii, representative for ether-bound isoprenoid lipids. Surprisingly, IPLs with phosphoester-bound head groups showed approximately the same degradation rate as IPLs with glycosidic head groups. Furthermore, the results indicate a relatively fast degradation of S. cerevisiae IPLs with ester-bound moieties (analogs of bacterial membrane lipids and no significant degradation of archaeal IPLs with ether-bound moieties. Pore water and 16S rRNA-based DGGE analysis showed only a minor influence of the IPL source on microbial metabolism and community profiles. Due to our results, the IPL-based quantification of Archaea and Bacteria should be interpreted with caution.

  9. A laboratory experiment of intact polar lipid degradation in sandy sediments

    Directory of Open Access Journals (Sweden)

    J. Logemann

    2011-09-01

    Full Text Available Intact polar lipids (IPLs are considered biomarkers for living biomass. Their degradation in marine sediments, however, is poorly understood and complicates interpretation of their occurrence in geological samples. To investigate the turnover of IPLs, a degradation experiment with anoxic sandy sediments from the North Sea was conducted. Intact cells of two organisms that do not naturally occur in North Sea sediments were chosen as IPL sources: (i Saccharomyces cerevisiae, representative for ester-bound acyl lipids that also occur in Bacteria, and (ii the archaeon Haloferax volcanii, representative for ether-bound isoprenoid lipids. Surprisingly, IPLs with phosphoester-bound head groups showed approximately the same degradation rate as IPLs with glycosidic head groups. Furthermore, the results indicate a relatively fast degradation of S. cerevisiae IPLs with ester-bound moieties (analogs of bacterial membrane lipids and no significant degradation of archaeal IPLs with ether-bound moieties. Pore water and 16S rRNA-based DGGE analysis showed only a minor influence of the IPL source on microbial metabolism and community profiles. Due to our results, the IPL-based quantification of Archaea and Bacteria should be interpreted with caution.

  10. Transport behavior of groundwater protozoa and protozoan-sized microspheres in sandy aquifer sediments

    Science.gov (United States)

    Harvey, R.W.; Kinner, N.E.; Bunn, A.; MacDonald, D.; Metge, D.

    1995-01-01

    Transport behaviors of unidentified flagellated protozoa (flagellates) and flagellate-sized carboxylated microspheres in sandy, organically contaminated aquifer sediments were investigated in a small-scale (1 to 4-m travel distance) natural-gradient tracer test on Cape Cod and in flow-through columns packed with sieved (0.5-to 1.0-mm grain size) aquifer sediments. The minute (average in situ cell size, 2 to 3 ??m) flagellates, which are relatively abundant in the Cape Cod aquifer, were isolated from core samples, grown in a grass extract medium, labeled with hydroethidine (a vital eukaryotic stain), and coinjected into aquifer sediments along with bromide, a conservative tracer. The 2-??m flagellates appeared to be near the optimal size for transport, judging from flowthrough column experiments involving a polydispersed (0.7 to 6.2 ??m in diameter) suspension of carboxylated microspheres. However, immobilization within the aquifer sediments accounted for a log unit reduction over the first meter of travel compared with a log unit reduction over the first 10 m of travel for indigenous, free-living groundwater bacteria in earlier tests. High rates of flagellate immobilization in the presence of aquifer sediments also was observed in the laboratory. However, immobilization rates for the laboratory-grown flagellates (initially 4 to 5 ??m) injected into the aquifer were not constant and decreased noticeably with increasing time and distance of travel. The decrease in propensity for grain surfaces was accompanied by a decrease in cell size, as the flagellates presumably readapted to aquifer conditions. Retardation and apparent dispersion were generally at least twofold greater than those observed earlier for indigenous groundwater bacteria but were much closer to those observed for highly surface active carboxylated latex microspheres. Field and laboratory results suggest that 2- ??m carboxylated microspheres may be useful as analogs in investigating several abiotic

  11. Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments

    Science.gov (United States)

    Böer, S. I.; Arnosti, C.; van Beusekom, J. E. E.; Boetius, A.

    2009-07-01

    Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany). Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4-5) temporal variations that were mostly related to seasonal temperature change and to changes in substrate availability. These temporal patterns in enzymatic activity were barely reflected in bacterial (200-400 mmol C m-2) and microphytobenthic biomass (800-1500 mmol C m-2) or the sedimentary carbohydrate inventory (1300-2900 mmol C m-2), suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30-180 mmol C m-2, and a biomass turnover time of 2-18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

  12. Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments

    Directory of Open Access Journals (Sweden)

    A. Boetius

    2009-07-01

    Full Text Available Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany. Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4–5 temporal variations that were mostly related to seasonal temperature change and to changes in substrate availability. These temporal patterns in enzymatic activity were barely reflected in bacterial (200–400 mmol C m−2 and microphytobenthic biomass (800–1500 mmol C m−2 or the sedimentary carbohydrate inventory (1300–2900 mmol C m−2, suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30–180 mmol C m−2, and a biomass turnover time of 2–18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

  13. The effect of the dominant polychaete Scolelepis squamata on nematode colonisation in sandy beach sediments: An experimental approach

    Science.gov (United States)

    Maria, Tatiana F.; Esteves, André M.; Vanaverbeke, Jan; Vanreusel, Ann

    2011-09-01

    The effect of an abundant sandy beach polychaete, Scolelepis squamata, on the colonisation of defaunated sediments by marine nematodes indicates that sandy beach fauna can be partially controlled by biological interactions within and across size groups. Experimental cores, equipped with windows allowing infaunal colonisation, were filled with defaunated sandy beach sediment containing two different treatments with and without S. squamata. These cores were inserted into microcosms filled with sediment with indigenous meiofauna collected from the field. The treatments were incubated in the laboratory at ambient temperature and salinity for 2, 7, 14 and 21 days, in order to follow the colonisation process of the defaunated sediments by the indigenous nematode fauna over time. Nematodes initially colonised both treatments, with abundances of up to 10% of the densities in the control; after 2 weeks, nematode densities in the cores without S. squamata surpassed the control densities. Nematode assemblages in both treatments were not species rich, and also differed in composition from the natural assemblages. The most successful colonising species, Enoplolaimus litoralis, was rare in the surrounding sediment, suggesting that colonisation was determined by species-specific characteristics such as body size, motility and feeding strategy. Initially the presence of macrofauna did not affect the nematode community composition, but after 2 weeks of the experiment, the presence of the polychaete seemed to facilitate the earlier establishment of non-opportunistic species.

  14. Sound speed in air-filled sand and 03ine shallow-layer sandy sediments

    Institute of Scientific and Technical Information of China (English)

    QIAN Zuwen

    2009-01-01

    Based on the author's theory for acoustic propagation in granular media and by employing the extinction theorem, the sound speed formulae in these media were derived. The numerical computations of sound speed in 03ine sediments and air-filled sand were carried out, and the results demonstrated that under the normal atmosphere the sound speed in air- filled sand is lower than the sound speed in the air. The numerical results also indicated that the influence of scattering interaction between the grains upon the sound speed in the 03ine shallow-layer sandy sediments has to be taken into account; however, the influence of the viscous-wave interaction can be neglected. The theoretical results obtained from the rigid-granular model seem to match the measured data better than from the elastic-granular model, even the latter model fits better for the real situation, indicating further measurements are necessary in order to gain an insight into this problem thoroughly. Through an analysis of experimental data published in journals a conclusion can be drawn that the theory of granular media is suited to deal with the problems of the sound propagation in air-filled sand better than the theory of porous media.

  15. Transport of bisphenol-A in sandy aquifer sediment: Column experiment.

    Science.gov (United States)

    Zakari, Sissou; Liu, Hui; Tong, Lei; Wang, Yan; Liu, Jianfeng

    2016-02-01

    The present paper aims to study the transport behavior of bisphenol-A (BPA) in sandy aquifer so as to provide important parameters for the prediction and control of contaminant plume in aquifer. Miscible displacement experiments were conducted and the breakthrough curves (BTCs) were simulated using HYDRUS-1D software. The effects of pore-water velocity (10-52 cm h(-1)) and initial concentration (2.5-40 mg L(-1)) on the sorption were also investigated. The BTCs of BPA fit the linear first-order non-equilibrium two-site model. The parameters such as partition coefficient (K(d)), the fraction of instantaneous adsorption on "Type-1" sites (F), the first order sorption rate coefficient for the kinetic non-equilibrium (type-2) sites (α), the retardation coefficient (R), and sorption capacity (q(column)) were computed. Results showed that BPA transported 0.11-0.83 m with various pore water velocity in sandy sediment column when water flowed 1 m. The sorption of BPA was mainly caused by the instantaneous surface adsorption as F varied from 0.596 to 0.908. The transport velocity of BPA was affected by pore water velocity (v) and followed the linear equation 1/R = 0.0600 + 0.0110v (r(2) = 0.9724). The parameter K(d) were also closely related to v and followed the equation LnK(d) = 1.0023-0.0482v (r(2) = 0.9690). The sorption capacity was more related to the initial BPA concentration (C0) and followed the linear equation q(column) = 0.265 + 0.253C0 (r(2) = 0.9727). The parameter α was affected by both v and C0 whereas F was not dramatically affected by both.

  16. Impact of redox-stratification on the diversity and distribution of bacterial communities in sandy reef sediments in a microcosm

    Science.gov (United States)

    Gao, Zheng; Wang, Xin; Hannides, Angelos K.; Sansone, Francis J.; Wang, Guangyi

    2011-11-01

    Relationships between microbial communities and geochemical environments are important in marine microbial ecology and biogeochemistry. Although biogeochemical redox stratification has been well documented in marine sediments, its impact on microbial communities remains largely unknown. In this study, we applied denaturing gradient gel electrophoresis (DGGE) and clone library construction to investigate the diversity and stratification of bacterial communities in redox-stratified sandy reef sediments in a microcosm. A total of 88 Operational Taxonomic Units (OTU) were identified from 16S rRNA clone libraries constructed from sandy reef sediments in a laboratory microcosm. They were members of nine phyla and three candidate divisions, including Proteobacteria ( Alpha-, Beta-, Gamma-, Delta-, and Epsilonproteobacteria), Actinobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Verrucomicrobia, Spirochaetes, and the candidate divisions WS3, SO31 and AO19. The vast majority of these phylotypes are related to clone sequences from other marine sediments, but OTUs of Epsilonproteobacteria and WS3 are reported for the first time from permeable marine sediments. Several other OTUs are potential new bacterial phylotypes because of their low similarity with reference sequences. Results from the 16S rRNA, gene clone sequence analyses suggested that bacterial communities exhibit clear stratification across large redox gradients in these sediments, with the highest diversity found in the anoxic layer (15-25 mm) and the least diversity in the suboxic layer (3-5 mm). Analysis of the nosZ, and amoA gene libraries also indicated the stratification of denitrifiers and nitrifiers, with their highest diversity being in the anoxic and oxic sediment layers, respectively. These results indicated that redox-stratification can affect the distribution of bacterial communities in sandy reef sediments.

  17. Impact of redox-stratification on the diversity and distribution of bacterial communities in sandy reef sediments in a microcosm

    Institute of Scientific and Technical Information of China (English)

    GAO Zheng; WANG Xin; Angelos K. HANNIDES; Francis J. SANSONE; WANG Guangyi

    2011-01-01

    Relationships between microbial communities and geochemical environments are important in marine microbial ecology and biogeochemistry.Although biogeochemical redox stratification has been well documented in marine sediments,its impact on microbial communities remains largely unknown.In this study,we applied denaturing gradient gel electrophoresis (DGGE) and clone library construction to investigate the diversity and stratification of bacterial communities in redox-stratified sandy reef sediments in a microcosm.A total of 88 Operational Taxonomic Units (OTU) were identified from 16S rRNA clone libraries constructed from sandy reef sediments in a laboratory microcosm.They were members of nine phyla and three candidate divisions,including Proteobacteria (Alpha-,Beta-,Gamma-,Delta-,and Epsilonproteobacteria),Actinobacteria,Acidobacteria,Bacteroidetes,Chloroflexi,Cyanobacteria,Firmicutes,Verrucomicrobia,Spirochaetes,and the candidate divisions WS3,SO31 and AO19.The vast majority of these phylotypes are related to clone sequences from other marine sediments,but OTUs of Epsilonproteobacteria and WS3 are reported for the first time from permeable marine sediments.Several other OTUs are potential new bacterial phylotypes because of their low similarity with reference sequences.Results from the 16S rRNA,gene clone sequence analyses suggested that bacterial communities exhibit clear stratification across large redox gradients in these sediments,with the highest diversity found in the anoxic layer (15-25 mm) and the least diversity in the suboxic layer (3-5 mm).Analysis of the nosZ,and amoA gene libraries also indicated the stratification of denitrifiers and nitrifiers,with their highest diversity being in the anoxic and oxic sediment layers,respectively.These results indicated that redox-stratification can affect the distribution of bacterial communities in sandy reef sediments.

  18. Effect of advective pore water flow on degradation of organic matter in permeable sandy sediment : - A study of fresh- and brackish water

    OpenAIRE

    2005-01-01

    The carbon metabolism in costal sediments is of major importance for the global carbon cycle. Costal sediments are also subjected to physical forcing generating water fluxes above and through the sediments, but how the physical affect the carbon metabolism is currently poorly known. In this study, the effect of advective pore water flow on degradation of organic matter in permeable sandy sediment was investigated in a laboratory study during wintertime. Sediments were collected from both brac...

  19. Marine meiofauna, carbon and nitrogen mineralization in sandy and soft sediments of Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Rysgaard, S.; Christensen, P.B.; Sørensen, Martin Vinther

    2000-01-01

    belonging to Platyhelminthes, Rotifera, Gastrotricha, and Protodriloidae (Polychaeta) occurred only at the sandy locality, whereas Kinorhyncha, Foraminifera, and Cumacea (Crustacea) occurred only at the muddy stations. The larger number of meiofauna individuals at the sandy locality may in part be explained...

  20. Time-lapse imagery of the breaching of Marmot Dam, Oregon, and subsequent erosion of sediment by the Sandy River, October 2007 to May 2008

    Science.gov (United States)

    Major, Jon J.; Spicer, Kurt R.; Collins, Rebecca A.

    2010-01-01

    In 2007, Marmot Dam on the Sandy River, Oregon, was removed and a temporary cofferdam standing in its place was breached, allowing the river to flow freely along its entire length. Time-lapse imagery obtained from a network of digital single-lens reflex cameras placed around the lower reach of the sediment-filled reservoir behind the dam details rapid erosion of sediment by the Sandy River after breaching of the cofferdam. Within hours of the breaching, the Sandy River eroded much of the nearly 15-m-thick frontal part of the sediment wedge impounded behind the former concrete dam; within 24-60 hours it eroded approximately 125,000 m3 of sediment impounded in the lower 300-meter-reach of the reservoir. The imagery shows that the sediment eroded initially through vertical incision, but that lateral erosion rapidly became an important process.

  1. Environmental implications of the use of sulfidic back-bay sediments for dune reconstruction — Lessons learned post Hurricane Sandy

    Science.gov (United States)

    Plumlee, Geoffrey S.; Benzel, William M.; Hoefen, Todd M.; Hageman, Philip L.; Morman, Suzette A.; Reilly, Timothy J.; Adams, Monique; Berry, Cyrus J.; Fischer, Jeffrey; Fisher, Irene

    2016-01-01

    Some barrier-island dunes damaged or destroyed by Hurricane Sandy's storm surges in October 2012 have been reconstructed using sediments dredged from back bays. These sand-, clay-, and iron sulfide-rich sediments were used to make berm-like cores for the reconstructed dunes, which were then covered by beach sand. In November 2013, we sampled and analyzed partially weathered materials collected from the cores of reconstructed dunes. There are generally low levels of metal toxicants in the reconstructed dune materials. However oxidation of reactive iron sulfides by percolating rainwater produces acid-sulfate pore waters, which evaporate during dry periods to produce efflorescent gypsum and sodium jarosite salts. The results suggest use of sulfidic sediments in dune reconstruction has both drawbacks (e.g., potential to generate acid runoff from dune cores following rainfall, enhanced corrosion of steel bulwarks) and possible benefits (e.g., efflorescent salts may enhance structural integrity).

  2. Environmental implications of the use of sulfidic back-bay sediments for dune reconstruction - Lessons learned post Hurricane Sandy.

    Science.gov (United States)

    Plumlee, Geoffrey S; Benzel, William M; Hoefen, Todd M; Hageman, Philip L; Morman, Suzette A; Reilly, Timothy J; Adams, Monique; Berry, Cyrus J; Fischer, Jeffrey M; Fisher, Irene

    2016-06-30

    Some barrier-island dunes damaged or destroyed by Hurricane Sandy's storm surges in October 2012 have been reconstructed using sediments dredged from back bays. These sand-, clay-, and iron sulfide-rich sediments were used to make berm-like cores for the reconstructed dunes, which were then covered by beach sand. In November 2013, we sampled and analyzed partially weathered materials collected from the cores of reconstructed dunes. There are generally low levels of metal toxicants in the reconstructed dune materials. However oxidation of reactive iron sulfides by percolating rainwater produces acid-sulfate pore waters, which evaporate during dry periods to produce efflorescent gypsum and sodium jarosite salts. The results suggest use of sulfidic sediments in dune reconstruction has both drawbacks (e.g., potential to generate acid runoff from dune cores following rainfall, enhanced corrosion of steel bulwarks) and possible benefits (e.g., efflorescent salts may enhance structural integrity).

  3. Benthic solute exchange and carbon mineralization in two shallow subtidal sandy sediments: Effect of advective pore-water exchange

    DEFF Research Database (Denmark)

    Cook, Perran L. M.; Wenzhofer, Frank; Glud, Ronnie N.;

    2007-01-01

    of O-2 distribution across ripples, and also deep subsurface O-2 pools, being observed. Mineralization pathways were predominantly aerobic when benthic mineralization rates were low and advective pore-water flow high as a result of well-developed sediment topography. By contrast, mineralization...... proceeded predominantly through sulfate reduction when benthic mineralization rates were high and advective pore-water flow low as a result of poorly developed topography. Previous studies of benthic mineralization in shallow sandy sediments have generally ignored these dynamics and, hence, have overlooked......We conducted four field campaigns to evaluate benthic O-2 consumption and the effect of advective pore-water flow in nearshore permeable sediments in the North Sea and Baltic Sea. Advective pore-water transport had a marked effect on the benthic exchange of O-2 and TCO2 in benthic chamber...

  4. Temporal dynamics of gastropod fauna on subtidal sandy sediments of the Ensenada de Baiona (NW Iberian Peninsula)

    Science.gov (United States)

    Moreira, J.; Aldea, C.; Troncoso, J. S.

    2010-12-01

    The temporal variation of the gastropod fauna inhabiting sandy sediments of the Ensenada de Baiona (Galicia, Spain) was studied at three subtidal sites from February 1996 to February 1997 by means of quantitative sampling. A total of 5,463 individuals representing 51 gastropod species and 22 families were found. The family Pyramidellidae was the most diverse in number of species (11 species), followed by Rissoidae and Trochidae (4 species each). The dogwhelk, Nassarius reticulatus, and the rissoid snail, Rissoa parva, were the numerically dominant species at the three studied sites; those and other abundant species showed their greatest densities by the end of summer and the beginning of autumn. In general, univariate measures of the assemblage (number of species, abundance, diversity and evenness) showed variations through time; greater values were recorded between summer and autumn depending on the site. Multivariate analyses done on abundance data showed certain seasonality in the evolution of the assemblage as expected for shallow subtidal sandy sediments at temperate latitudes; those seasonal changes were mostly related to variations in abundance of numerically dominant species. Although the measured sedimentary variables did not show significant correlations with faunal univariate parameters, sediment heterogeneity due to the presence of mats of Zostera marina L. and shells of dead bivalves might explain the differences in composition of the gastropod assemblage among sampling sites.

  5. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, F. L.; Woodrow, D. L.; McGann, M. L.

    2012-12-01

    Heavy minerals have been used to trace the sources and transportation of sandy sediment in San Francisco Bay and nearby coastal areas since the 1960s. We have the opportunity to sample similar environments and revisit the heavy mineral populations under the current San Francisco Coastal System study of the provenance of beach sand. Most of the sandy sediment in San Francisco Bay can be traced to distant sources including the Sierra Nevada batholith and associated terranes with local contributions from the Franciscan Complex. Heavy minerals from Sierran sources include ordinary hornblende, metamorphic amphiboles, and hypersthene while those from the Franciscan Complex include other types of pyroxene, epidote, basaltic hornblende, and glaucophane... Tertiary strata and volcanics in the surrounding hills and displaced Sierran rocks found on the continental shelf west of the San Andreas Fault Zone introduce similar minerals, but perhaps in a lesser volume to be identified as major contributors... The primary result of cluster analysis of heavy minerals separated from sand-sized sediment taken within San Francisco Bay, the adjacent continental shelf, local beaches, cliffs outside the Golden Gate, and upstream drainages indicate a widespread occurrence of sediment traceable to the Sierra Nevada. A second cluster of samples identifies samples of mixed Sierran and Franciscan lineage within the strait of the Golden Gate, on the San Francisco bar, and on coastal beaches. Sediment samples with predominantly Franciscan mineral content appear on beaches around Point Reyes, possibly transported from the Russian River. The heavy mineral composition supports transport from the east, through San Francisco Bay and out the Golden Gate to the San Francisco bar and southward.

  6. Geomechanical, Hydraulic and Thermal Characteristics of Deep Oceanic Sandy Sediments Recovered during the Second Ulleung Basin Gas Hydrate Expedition

    Directory of Open Access Journals (Sweden)

    Yohan Cha

    2016-09-01

    Full Text Available This study investigates the geomechanical, hydraulic and thermal characteristics of natural sandy sediments collected during the Ulleung Basin gas hydrate expedition 2, East Sea, offshore Korea. The studied sediment formation is considered as a potential target reservoir for natural gas production. The sediments contained silt, clay and sand fractions of 21%, 1.3% and 77.7%, respectively, as well as diatomaceous minerals with internal pores. The peak friction angle and critical state (or residual state friction angle under drained conditions were ~26° and ~22°, respectively. There was minimal or no apparent cohesion intercept. Stress- and strain-dependent elastic moduli, such as tangential modulus and secant modulus, were identified. The sediment stiffness increased with increasing confining stress, but degraded with increasing strain regime. Variations in water permeability with water saturation were obtained by fitting experimental matric suction-water saturation data to the Maulem-van Genuchen model. A significant reduction in thermal conductivity (from ~1.4–1.6 to ~0.5–0.7 W·m−1·K−1 was observed when water saturation decreased from 100% to ~10%–20%. In addition, the electrical resistance increased quasi-linearly with decreasing water saturation. The geomechanical, hydraulic and thermal properties of the hydrate-free sediments reported herein can be used as the baseline when predicting properties and behavior of the sediments containing hydrates, and when the hydrates dissociate during gas production. The variations in thermal and hydraulic properties with changing water and gas saturation can be used to assess gas production rates from hydrate-bearing deposits. In addition, while depressurization of hydrate-bearing sediments inevitably causes deformation of sediments under drained conditions, the obtained strength and stiffness properties and stress-strain responses of the sedimentary formation under drained loading conditions

  7. Estuarine bed-sediment-quality data collected in New Jersey and New York after Hurricane Sandy, 2013

    Science.gov (United States)

    Fischer, Jeffrey M.; Phillips, Patrick J.; Reilly, Timothy J.; Focazio, Michael J.; Loftin, Keith A.; Benzel, William M.; Jones, Daniel K.; Smalling, Kelly L.; Fisher, Shawn C.; Fisher, Irene J.; Iwanowicz, Luke R.; Romanok, Kristin M.; Jenkins, Darkus E.; Bowers, Luke; Boehlke, Adam; Foreman, William T.; Deetz, Anna C.; Carper, Lisa G.; Imbrigiotta, Thomas E.; Birdwell, Justin E.

    2015-01-01

    This report describes a reconnaissance study of estuarine bed-sediment quality conducted June–October 2013 in New Jersey and New York after Hurricane Sandy in October 2012 to assess the extent of contamination and the potential long-term human and ecological impacts of the storm. The study, funded through the Disaster Relief Appropriations Act of 2013 (PL 113-2), was conducted by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency and the National Oceanographic and Atmospheric Administration. In addition to presenting the bed-sediment-quality data, the report describes the study design, documents the methods of sample collection and analysis, and discusses the steps taken to assure the quality of the data.

  8. Regional variability in bed-sediment concentrations of wastewater compounds, hormones and PAHs for portions of coastal New York and New Jersey impacted by hurricane Sandy

    Science.gov (United States)

    Phillips, Patrick; Gibson, Cathy A; Fisher, Shawn C.; Fisher, Irene; Reilly, Timothy J.; Smalling, Kelly L.; Romanok, Kristin M.; Foreman, William T.; ReVello, Rhiannon C.; Focazio, Michael J.; Jones, Daniel K.

    2016-01-01

    Bed sediment samples from 79 coastal New York and New Jersey, USA sites were analyzed for 75 compounds including wastewater associated contaminants, PAHs, and other organic compounds to assess the post-Hurricane Sandy distribution of organic contaminants among six regions. These results provide the first assessment of wastewater compounds, hormones, and PAHs in bed sediment for this region. Concentrations of most wastewater contaminants and PAHs were highest in the most developed region (Upper Harbor/Newark Bay, UHNB) and reflected the wastewater inputs to this area. Although the lack of pre-Hurricane Sandy data for most of these compounds make it impossible to assess the effect of the storm on wastewater contaminant concentrations, PAH concentrations in the UHNB region reflect pre-Hurricane Sandy conditions in this region. Lower hormone concentrations than predicted by the total organic carbon relation occurred in UHNB samples, suggesting that hormones are being degraded in the UHNB region.

  9. Hurricane Sandy's Impact on Coastal Sedimentation on Long Island's South Shore: Results from a 2013 Rapid Response Study

    Science.gov (United States)

    Christensen, B. A.; Goff, J. A.; Flood, R. D.; Austin, J. A., Jr.; Browne, C. M.; Saustrup, S.

    2014-12-01

    To understand the impact of Hurricane Sandy on the NY coast, we conducted subsurface and multi-beam analyses, ground-truthed by grab samples, in 3 areas: the western end of Fire Island (FIW), eastern Fire Island (FIE) where a new inlet formed during the storm, and Long Beach (LB). Grab samples yielded sands and muds, a surprise given the shallow (10-25m) water depths. Muds rested on top of sands and were removed for additional analyses. Since percent mud could not be determined absolutely, sediments were washed through a 63 mm sieve, RoTapped for 10 minutes at ¼ Φ, and weight percent calculated for the coarse fraction. At FIW and FIE, fine sands dominate the shallowest depths studied, consistent with previous studies. At FIE, the sedimentary wedge extends to ~15m, with finest sands (peak 3-3.5 Φ) in shallowest waters surveyed (~10m). Slightly coarser (2.5Φ) sediments plus relict gravels are present in swales where the wedge shoals. This supports mapping results indicating sand ridges migrated to the SW. Medium to fine sand is present at the deepest extent of the wedge; the grain size distribution matches a sample taken in the swash zone on the eastern flank of the new breach. Sediments may have been transported shoreward and then reworked post-Sandy. Samples seaward of the new breach were capped by a mud layer, which in turn had a layer of fine sand resting on it, evidence of a nascent ebb tidal deposit. At FIW, sediments in the shallow NE swale are finer (3.5Φ) and better sorted. As the region is underlain by relict sediments, these fine sands may be relicts exposed by storm-driven bedform migration. Deeper water (~22m w.d.) samples at FIW are coarser and contain shell hash. Sand on the lee side of the sand ridge, which CHIRP profiles show did not migrate significantly and accumulated sands, are medium (1.5 Φ), and match the grain sizes found on Fire Island beach. Muds contain heavy metals in concentrations consistent with transport from adjacent estuaries.

  10. Effect of nutrient availability on carbon and nitrogen incorporation and flows through benthic algae and bacteria in near-shore sandy sediment

    NARCIS (Netherlands)

    Cook, P.; Veuger, B.; Böer, S.; Middelburg, J.J.

    2007-01-01

    Carbon and nitrogen uptake in a microbial community comprising bacteria and microalgae in a sandy marine sediment under nutrient-limited and -replete conditions was studied using a mesocosm approach. After 2 wk of incubation, a pulse of H13CO3– and 15NH4+ was added to the mesocosms, and subsequent

  11. Species-specific effect of macrobenthic assemblages on meiobenthos and nematode community structure in shallow sandy sediments.

    Science.gov (United States)

    Urban-Malinga, Barbara; Drgas, Aleksander; Gromisz, Sławomira; Barnes, Natalie

    2014-01-01

    Three functionally different macrofaunal species (the filter- and/or surface deposit-feeding polychaete Hediste diversicolor, and the suspension-feeding bivalves Mya arenaria and Cerastoderma glaucum) were introduced as single- and two-species treatments into microcosms containing sandy sediment with a natural meiofaunal community. H. diversicolor is a burrowing species building a system of galleries, C. glaucum lives actively near the sediment surface acting as a biodiffuser and M. arenaria buries deeply and leads a sessile lifestyle. It is shown that H. diversicolor extended the vertical distribution of meiofauna into deeper sediment layers compared to the control and non-Hediste treatments. The response of the nematode community varied significantly among treatments and was dependant on the macrobenthic species composition but not on the species number. Nematode assemblages in all treatments with the polychaete, both in monoculture and with either bivalve, differed significantly from those recorded in other treatments and were more similar than replicates within any other single treatment. H. diversicolor also appeared to have stimulated nematode species diversity. The present study demonstrated that the impact of macrobenthic assemblages on meiofauna is not a simple summation of individual species effects but is species specific.

  12. SANDY: A Matlab tool to estimate the sediment size distribution from a sieve analysis

    Science.gov (United States)

    Ruiz-Martínez, Gabriel; Rivillas-Ospina, Germán Daniel; Mariño-Tapia, Ismael; Posada-Vanegas, Gregorio

    2016-07-01

    This paper presents a new computational tool called SANDY© which calculates the sediment size distribution and its textural parameters from a sieved sediment sample using Matlab®. The tool has been developed for professionals involved in the study of sediment transport along coastal margins, estuaries, rivers and desert dunes. The algorithm uses several types of statistical analyses to obtain the main textural characteristics of the sediment sample (D50, mean, sorting, skewness and kurtosis). SANDY© includes the method of moments (geometric, arithmetic and logarithmic approaches) and graphical methods (geometric, arithmetic and mixed approaches). In addition, it provides graphs of the sediment size distribution and its classification. The computational tool automatically exports all the graphs as enhanced metafile images and the final report is also exported as a plain text file. Parameters related to bed roughness such as Nikuradse and roughness length are also computed. Theoretical depositional environments are established by a discriminant function analysis. Using the uniformity coefficient the hydraulic conductivity of the sand as well as the porosity and void ratio of the sediment sample are obtained. The maximum relative density related to sand compaction is also computed. The Matlab® routine can compute one or several samples. SANDY© is a useful tool for estimating the sediment textural parameters which are the basis for studies of sediment transport.

  13. Marine meiofauna, carbon and nitrogen mineralization in sandy and soft sediments of Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Rysgaard, S.; Christensen, P.B.; Sørensen, Martin Vinther

    2000-01-01

    layers of the sediment. Algal photosynthetic activity and nitrogen uptake reduced nitrogen effluxes and denitrification rates. Sulfate reduction was the most important pathway for carbon mineralization in the sediments of the shallow-water station. In contrast, high bottom-water NO3- concentrations...... and a relatively deep O-2 penetration into the sediment at the deep-water stations ensured high denitrification activity, particularly as a result of an efficient coupling between nitrification and denitrification. Denitrification accounted for up to 33 % of total carbon mineralization in the deep-water sediment......, corresponding to the 3 times higher number of meiofauna found in the upper 2 cm of this sediment. Thus, meiofauna increased the transport of solutes as compared to molecular diffusion by a factor of 1.5 to 3.1, thereby stimulating microbial mineralization...

  14. Study on sound-speed dispersion in a sandy sediment at frequency ranges of 0.5-3 kHz and 90-170 kHz

    Science.gov (United States)

    Yu, Sheng-qi; Liu, Bao-hua; Yu, Kai-ben; Kan, Guang-ming; Yang, Zhi-guo

    2017-03-01

    In order to study the properties of sound-speed dispersion in a sandy sediment, the sound speed was measured both at high frequency (90-170 kHz) and low frequency (0.5-3 kHz) in laboratory environments. At high frequency, a sampling measurement was conducted with boiled and uncooked sand samples collected from the bottom of a large water tank. The sound speed was directly obtained through transmission measurement using single source and single hydrophone. At low frequency, an in situ measurement was conducted in the water tank, where the sandy sediment had been homogeneously paved at the bottom for a long time. The sound speed was indirectly inverted according to the traveling time of signals received by three buried hydrophones in the sandy sediment and the geometry in experiment. The results show that the mean sound speed is approximate 1710-1713 m/s with a weak positive gradient in the sand sample after being boiled (as a method to eliminate bubbles as much as possible) at high frequency, which agrees well with the predictions of Biot theory, the effective density fluid model (EDFM) and Buckingham's theory. However, the sound speed in the uncooked sandy sediment obviously decreases (about 80%) both at high frequency and low frequency due to plenty of bubbles in existence. And the sound-speed dispersion performs a weak negative gradient at high frequency. Finally, a water-unsaturated Biot model is presented for trying to explain the decrease of sound speed in the sandy sediment with plenty of bubbles.

  15. Linking Arenicola marina irrigation behavior to oxygen transport and dynamics in sandy sediments

    DEFF Research Database (Denmark)

    Timmermann, Karen; Banta, Gary T.; Glud, Ronnie Nøhr

    2007-01-01

    In this study we examine how the irrigation behavior of the common lugworm Arenicola marina affects the distribution, transport and dynamics of oxygen in sediments using microelectrodes, planar optodes and diagenetic modeling. The irrigation pattern was characterized by a regular recurring periods...... mediated oxygen uptake of the burrow wall. Approximately 28% of the oxygen was consumed by the feeding pocket/funnel characterized by advective porewater transport. Model simulations indicated that oxygen injected into the sediment was usually consumed in a very narrow zone around the feeding pocket...... concentration in the burrow was high (80% air saturation) and oxygen was detected at distances up to 0.7 mm from the burrow wall. Volume specific oxygen consumption rates calculated from measured oxygen profiles were up to 4 times higher for sediments surrounding worm burrows as compared to surface sediments...

  16. Airflow and sediment movement within an inland blowout in Hulun Buir sandy grassland, Inner Mongolia, China

    Science.gov (United States)

    Sun, Yu; Hasi, Eerdun; Liu, Meiping; Du, Huishi; Guan, Chao; Tao, Binbin

    2016-09-01

    We measured wind flows and sediment transport rates through a blowout in Hulun Buir grassland, Inner Mongolia. Topography and the angle of incidence between the approaching wind and the blowout long-axis significantly affected the air flow. Flow separated and decelerated at the western wall and accelerated towards the east, until maximum wind speed occurred at the top of the depositional lobe, and then decelerated on the lee side. When airflow emerged on the eastern wall, resultant directions were always NW. When winds approached from directions within 17.5° of the blowout axis, both the northwestern and southwestern walls developed turbulent flow, and significant topographic steering occurred. The deceleration zone expanded eastwards from 10.3 to 12.8 m from the western rim. When the wind direction was more oblique than 17.5°, turbulent flow at the southwestern wall disappeared. 'S-shaped' flow intensified, causing more pronounced steering at the bottom, but topographic steering elsewhere was reduced, and the boundary of the deceleration moved to 10 m from the western rim. Minor sediment deposition occurred on the western wall, while other parts were eroded; maximum sediment transport occurred at the top of the depositional lobe. The approaching wind speed affected the sediment transport rate more than the direction; and spatial variability in sediment transport reflected differences in compaction, vegetation coverage, slope, aspect, and upwind sediment availability, resulting in asymmetrical development. Overall, flow-form interactions governed the flow structures and controlled the evolution of the blowout via sediment transport.

  17. Effects of bioturbation on the fate of oil in coastal sandy sediments - An in situ experiment

    DEFF Research Database (Denmark)

    Timmermann, Karen; Banta, Gary T.; Klinge, Lars

    2011-01-01

    –MS and bioturbation activity (feces production and irrigation) was measured regularly during the experiment and used as input parameters in a mechanistic model describing the effects of A. marina on the transport and degradation of oil compounds in the sediment. The chemical analytical data and model results......Effects of bioturbation by the common lugworm Arenicola marina on the fate of oil hydrocarbons (alkanes and PAHs) were studied in situ during a simulated oil spill in a shallow coastal area of Roskilde fjord, Denmark. The fate of selected oil compounds was monitored during 120 d using GC...... indicated that A. marina had profound and predictable effects on the distribution, degradation and preservation of oil and that the net effect depended on the initial distribution of oil. In sediment with an oil contaminated subsurface-layer A. marina buried the layer deeper in the sediment which clearly...

  18. Eruption-related lahars and sedimentation response downstream of Mount Hood: Field guide to volcaniclastic deposits along the Sandy River, Oregon

    Science.gov (United States)

    Pierson, Tom C.; Scott, William E.; Vallance, James W.; Pringle, Patrick T.; O'Connor, Jim; Dorsey, Rebecca; Madin, Ian

    2009-01-01

    Late Holocene dome-building eruptions at Mount Hood during the Timberline and Old Maid eruptive periods resulted in numerous dome-collapse pyroclastic flows and lahars that moved large volumes of volcaniclastic sediment into temporary storage in headwater canyons of the Sandy River. During each eruptive period, accelerated sediment loading to the river through erosion and remobilization of volcanic fragmental debris resulted in very high sediment-transport rates in the Sandy River during rain- and snowmelt-induced floods. Large sediment loads in excess of the river's transport capacity led to channel aggradation, channel widening, and change to a braided channel form in the lowermost reach of the river, between 61 and 87 km downstream from the volcano. The post-eruption sediment load moved as a broad bed-material wave, which in the case of the Old Maid eruption took ~2 decades to crest 83 km downstream. Maximum post-eruption aggradation levels of at least 28 and 23 m were achieved in response to Timberline and Old Maid eruptions. In each case, downstream aggradation cycles were initiated by lahars, but the bulk of the aggradation was achieved by fluvial sediment transport and deposition. When the high rates of sediment supply began to diminish, the river degraded, incising the channel fills and forming progressively lower sets of degradational terraces. A variety of debris-flow, hyperconcentrated-flow, and fluvial (upper and lower flow regime) deposits record the downstream passage of the sediment waves that were initiated by these eruptions. The deposits also presage a hazard that may be faced by communities along the Sandy River when volcanic activity at Mount Hood resumes.

  19. Wave and sediment dynamics along a shallow subtidal sandy beach inhabited by modern stromatolites.

    Science.gov (United States)

    Eckman, J E; Andres, M S; Marinelli, R L; Bowlin, E; Reid, R P; Aspden, R J; Paterson, D M

    2008-01-01

    To help define the habitat of modern marine stromatolites, wave-dominated flow and sediment transport were studied in the shallow subtidal region (1-2 m depth) along the slightly concave, windward face of Highborne Cay, Exuma, Bahamas - the only face of the cay that includes a population of stromatolites concentrated near the region of highest curvature of the beach. Wave energy impacting this island's most exposed beach was driven by local wind forcing which increases largely in response to the passage of atmospheric disturbances that typically affect the region for periods of a few days. Although some wave energy is almost always noted (maximum horizontal orbital speeds at the bottom are rarely <10 cm s(-1)), wave conditions remain comparatively calm until local winds increase above speeds of approximately 3-4 m s(-1) at which point maximum wave speeds rapidly increase to 50-80 cm s(-1). Stromatolites, which are largely restricted to the shoreward side of a shallow platform reef, are sheltered by the reef beyond which wave speeds are one to four times higher (depending on tidal stage). Moreover, stromatolite populations are predominantly found along a region of this wave-exposed beach that experiences comparatively reduced wave energy because of the curved morphology of the island's face. Maximum wave speeds are 1.4 to 2 times higher along more northern sections of the beach just beyond the locus of stromatolite populations. A quantitative model of sediment transport was developed that accurately predicted accumulation of suspended sediment in sediment traps deployed in the shallow subtidal zone along this beach. This model, coupled with in situ wave records, indicates that gross rates of suspended sediment deposition should be two to three times higher northward of the main stromatolite populations. Regions of the beach containing stromatolites nevertheless should experience significant rates of gross suspended sediment deposition averaging 7-10 g cm(-2) day(-1

  20. Determining the solid phases hosting arsenic in Mekong Delta sediments

    Science.gov (United States)

    Wucher, M.; Stuckey, J. W.; McCurdy, S.; Fendorf, S.

    2011-12-01

    The major river systems originating from the Himalaya deposit arsenic bearing sediment into the deltas of South and Southeast Asia. High rates of sediment and organic carbon deposition combined with frequent flooding leads to anaerobic processes that release arsenic into the pore-water. Arsenic concentrations in the groundwater of these sedimentary basins are often above the World Health Organization drinking water standard of 10 μg As L-1. As a result, 150 million people are at risk of chronic arsenic poisoning through water and rice consumption. The composition of the iron bearing phases hosting the arsenic in these deltaic sediments is poorly understood. Here we implemented a suite of selective chemical extractions to help constrain the types of arsenic bearing solid phases, which were complimented with synchrotron-based X-ray absorption spectroscopy and X-ray diffraction analyses to define the arsenic and iron mineralogy of the system. Sediment cores were collected in triplicate from a seasonally-inundated wetland in Cambodia at depths of 10, 50, 100, and 150 centimeters. We hypothesize that (i) arsenic will be predominantly associated with iron oxides, and (ii) the ratio of crystalline to amorphous iron oxides will increase with sediment depth (and age). We performed four selective extractions in parallel to quantify the various pools of arsenic. First, 1 M MgCl2 was used to extract electrostatically-bound arsenic (labile forms) from the sediment. Second, 1 M NaH2PO4 targeted strongly adsorbed arsenic. Third, 1 M HCl was used to liberated arsenic coprecipitated with amorphous Fe/Mn oxides, carbonates, and acid-volatile sulfides. Finally, a dithionite extraction was used to account for arsenic associated with reducible Fe/Mn oxides. Through this work, we identified the composition of the phases hosting arsenic at various depths through the soil profile, improving our understanding of how arsenic persists in the aquifer. In addition, defining the arsenic and

  1. Photosynthesis as a Possible Source of Gas Bubbles in Shallow Sandy Coastal Sediments

    Science.gov (United States)

    2012-09-30

    clearly demonstrates that gas bubbles can be formed when photosynthesis by benthic microalgae causes pore water to become supersaturated with oxygen...We also collected sediment samples from the upper few mm of sand to identify the dominant taxa of benthic microalgae present. Although benthic...Jan Rines (Graduate School of Oceanography / University of Rhode Island = GSO/URI) to identify the benthic microalgae in the samples. Following the

  2. Assessment of spatial flow patterns in unsaturated sandy alluvial sediments using high- resolution GPR.

    Science.gov (United States)

    Haarder, E. B.; Looms, M. C.; Nielsen, L.; Jensen, K. H.

    2008-12-01

    Traditional sampling and monitoring techniques have inherent limitations in capturing the detailed spatial patterns of water flow in the unsaturated zone particularly for complex flow conditions such as unstable wetting fronts or preferential flow. Dye tracer experiments can help visualise the dynamics of water flow but they are highly destructive as well. High-resolution Ground Penetrating Radar (GPR) is an attractive technique for non-destructive mapping of soil moisture changes and thus flow patterns in the shallow subsurface. In this study we test the method at a field site in western Denmark developed on a sandy alluvial outwash plane. We compare high-resolution reflection GPR data with visual observations from a dye tracer experiment using Brilliant Blue (BB). 100 mm of BB-stained water was infiltrated over a 5x5 m area and 3D reflection GPR data sets using high-frequency antennae were collected before and after infiltration. Subsequently a 2 m deep trench was excavated for visual observations of the flow patterns in a cross-section as evidenced by the dye staining patterns. The dye infiltration experiment had an overall attenuating effect on the GPR signal, and reflections were delayed significantly because of the increase in soil moisture. In the excavated cross-section we found a reasonable agreement between the areas subject to attenuation of the GPR signal and the areas affected by dye. Also, we found that displacement flow was responsible for a delay of deeper reflections below the extend of the dye staining. An amplitude analysis performed for a shallow 1.3 m thick section shows a general decrease in electromagnetic wave amplitude within the region bounded by the area exposed to infiltration, but also suggests that lateral flow along sedimentary boundaries occurs. The results suggest that high-resolution GPR provides important insight into the spatial patterns of unsaturated flow and highlight the applicability of this method as a non-destructive means

  3. Balance Between Autotrophic and Heterotrophic Components and Processes in Microbenthic Communities of Sandy Sediments: A Field Study

    Science.gov (United States)

    Sundbäck, Kristina; Nilsson, Per; Nilsson, Claes; Jönsson, Benno

    1996-12-01

    The microscopic community of a microtidal sandy sediment on the Swedish west coast was studied in situat two depths (0·5 and 4 m) on four occasions (January, April, August and October). Biomass of microalgae, bacteria, ciliates and meiofauna, as well as primary and bacterial productivity, were quantified. Meiofaunal grazing on algae and bacteria was measured simultaneously by radiolabelling intact sediment cores. Autotrophic biomass dominated the microbial community at both depths and on all sampling occasions, accounting for 47-87% of the microbial biomass. Meiofauna contributed 10-47%, while bacteria and ciliates together made up less than 6%. The microflora was dominated by attached (epipsammic) diatoms, but occasional ' blooms ' of motile species occurred. Vital cells of planktonic diatoms contributed to benthic algal biomass in spring. Primary productivity exceeded bacterial productivity in April and August at both depths, while the balance was reversed in October and January. Meiofauna grazed between 2 and 12% of the algal biomass per day, and between 0·3 and 37% of the bacterial biomass. Almost an order of magnitude more algal (17-138 mg C m -2) than bacterial (0·1-33 mg C m -2) carbon was grazed daily. At the shallow site, primary productivity always exceeded grazing rates on algae, whereas at the deeper site, grazing exceeded primary productivity in October and January. Bacterial productivity exceeded grazing at both depths on all four occasions. Thus, meiofaunal grazing seasonally controlled microalgal, but not bacterial, biomass. These results suggest that, during summer, only a minor fraction (food web ' through meiofauna. During spring and autumn, however, a much larger fraction (≈30-60%) of primary production may pass through meiofauna. During winter, meiofaunal grazing is a less important link in the shallow zone, but at sublittoral depths, algal productivity may be limiting, and meiofauna depend on other food sources, such as bacteria and

  4. Sandy inland braidplain deposition with local aeolian sedimentation in the lower and middle parts of the buntsandstein and sandy coastal braidplain deposition in the topmost zechstein in the sudetes (Lower Silesia, Poland)

    Science.gov (United States)

    Mroczkowski, Jerzy; Mader, Detlef

    The lower and middle parts of the Buntsandstein between Röt and Zechstein in the Sudetes (Lower Silesia, Poland) crop out in the marginal seams of the North Sudetic Trough and the Intra Sudetic Trough. The continental red beds originate in predominantly sandy braided river systems of an extensive inland alluvial plain in almost arid climate. The sediments are laid down in channels and floodplains of a moderately- to highly-braided, sandy to pebbly stream complex consisting of narrowly- to moderately-spaced low-sinuosity watercourses and narrow to wide overbank plains between the channels. Rapid aggradation and abandonment, quick lateral migration or high avulsion rates of the considerably mobile streams result in effective combing of the interchannel areas. Persistent high-energy overspilling of watercourse banks and invasion of bed-load-saturated flood surges into the overbank areas often lead to primary restriction or even suppression of formation of topstratum suspension fines. Secondarily, the silty-clayey and fine sandy overbank sediments which could occasionally originate in remote or sheltered lakes and ponds are frequently completely reworked by considerable lateral and vertical erosion during sidewards displacement of the rivers. As a result of both primary-depositional restriction and secondary-erosional removal of floodplain fines, the channel sediments are commonly stacked upon each other to multistorey stream sand complexes. Emergence and desiccation of parts of the alluvial plain sometimes give rise to aeolian deflation and accumulation of the winnowed sand to small dunelets and wind ripple trains. The aeolian depositional environment representing a more peripheral erg facies with sheet sand interdune milieu could not be fully ascertained due to poor outcrop conditions, but is likely to occur locally in view of comparative interpretation with other mixed dune and river sand sequences in the Mid-European Buntsandstein. Variations of fluvial style are

  5. Sediment and discharge yields within a minimally disturbed, headwater watershed in North Central Pennsylvania, USA, with an emphasis on Superstorm Sandy

    Science.gov (United States)

    Maloney, Kelly O.; Shull, Dustin R.

    2015-01-01

    We estimated discharge and suspended sediment (SS) yield in a minimally disturbed watershed in North Central Pennsylvania, USA, and compared a typical storm (September storm, 4.80 cm) to a large storm (Superstorm Sandy, 7.47 cm rainfall). Depending on branch, Sandy contributed 9.7–19.9 times more discharge and 11.5–37.4 times more SS than the September storm. During the September storm, the upper two branches accounted for 60.6% of discharge and 88.8% of SS at Lower Branch; during Sandy these percentages dropped to 36.1% for discharge and 30.1% for SS. The branch with close proximity roads had over two-three times per area SS yield than the branch without such roads. Hysteresis loops showed typical clockwise patterns for the September storm and more complicated patterns for Sandy, reflecting the multipeak event. Estimates of SS and hysteresis in minimally disturbed watersheds provide useful information that can be compared spatially and temporally to facilitate management.

  6. Caesium-137 in sandy sediments of the River Loire (FR): Assessment of an alluvial island evolving over the last 50 years

    Energy Technology Data Exchange (ETDEWEB)

    Detriche, Sebastien; Rodrigues, Stephane; Macaire, Jean-Jacques; Breheret, Jean-Gabriel; Bakyono, Jean-Paul [Universite Francois-Rabelais de Tours, CNRS/INSU UMR 6113 ISTO, Universite d' Orleans Faculte des Sciences et Techniques, Laboratoire de Geologie des Environnements Aquatiques Continentaux, Parc de Grandmont, 37200 Tours (France); Bonte, Philippe [UMR CNRS-CEA 1572, Laboratoire des Sciences du Climat et de l' Environnement - LSCE, CNRS, Domaine du CNRS, Bat. 12, 91198 Gif-sur-Yvette (France); Juge, Philippe [CETU-Elmis ingenieries, Antenne Universitaire en Val de Vienne, 11 quai Danton, 37500 Chinon (France)

    2010-07-01

    Recent sedimentological and morphological evolution of an island in the River Loire (FR) was investigated using the {sup 137}Cs method. This study describes the morphological adjustment of the island in the last 50 years, which corresponds to the increased bed incision of this sandy, multiple-channel environment because of, among other things, the increase in sediment extraction up to 1995. The results show that some {sup 137}Cs can be retained by sandy particles, potentially in clay minerals forming weathering features included in detrital sand grains. From a morphological perspective, significant lateral erosion can be observed in the upstream part of the island, while a weak lateral accretion occurs in its downstream section. Data about {sup 137}Cs and aerial photographs show that the morphology of the island margins has undergone significant changes leading to a lateral migration, while the centre of the island has remained relatively stable or is slowly eroding. The migration of the island depends on: (1) the withdrawal of inherited pre-incision morphological units, such as levees, or the development of new units, such as a channel shelf; (2) water and sediment supply from surrounding channels during flood events; (3) preferential sediment trapping (20 mm year{sup -1}) from the presence of riparian vegetation on the bank of the secondary channel that is subject to narrowing. The sedimentological and morphological response of the island in the context of incision of the Loire river bed is expressed mainly by lateral migration and secondarily by a low vertical adjustment. (authors)

  7. Sediment-hosted Pb-Zn Deposits: a global perspective

    Science.gov (United States)

    Leach, David L.; Sangster, Donald F.; Kelley, Karen D.; Large, R; Garven, G.; Allen, Craig R.

    2005-01-01

    Sediment-hosted Pb-Zn deposits contain the world's greatest lead and zinc resources and dominate world production of these metals. They are a chverse group of ore deposits hosted by a wide variety of carbonate and siliciclastic roch that have no obviolls genetic association with igneous activity. A nmge of ore-fortl1ing processes in a vmiety of geologic and tectonic environments created these deposits over at least two billion years of Earth history. The metals were precipitated by basinal brines in synsedimentary and early diagenetic to low-grade metamorphic environments. The deposits display a broad range of relationships to enclosing host rocks that includes stratiform, strata-bound, and discordant ores. These ores are divided into two broad subt)1Jes: Mississippi Valley-type (MVT) and sedimentmy exhalative (SEDEX), Despite the "exhalative" component inherent in the term "SEDEX," in this manusclipt, direct evidence of an exhalite in the ore or alteration component is not essential for a deposit to be classified as SEDEX. The presence of laminated sulfides parallel to bedding is assumed to be permissive evidence for exhalative ores. The chstinction between some SEDEX and MVT depOSits can be quite subjective because some SEDEX ores replaced carbonate, whereas some MVT depOSits formed in an early diagenetic environment and display laminated ore textures. Geologic and resource information are presented for 248 depositS that provide a framework to describe ,mel compare these deposits. Nine of tlle 10 largest sediment-hosted Pb-Zn deposits are SEDEX, Of the deposits that contain at least 2.5 million metric tons (Mt), there are 35 SEDEX (excluding Broken Hill-type) deposits and 15 MVT (excluding Iris-type) deposits. Despite the skewed distribution of the deposit size, the two deposits types have an excellent correlation between total tonnage and tonnage of contained metal (Pb + Zn), with a fairly consistent ratio of about lO/l, regardless of the size of the deposit or

  8. Grain-size distribution characteristics of red sandy sediments in Dongjiang River valley, southern Nanling Mountains,during the MIS2 stage

    Institute of Scientific and Technical Information of China (English)

    ShuHuan Du; BaoSheng Li; DongFeng Niu; XiaoHao Wen; FengNian Wang; XianJiao Ou; Yi Yang; YueJun Si; XinNan Zhao

    2009-01-01

    Layer LJ3 of Linjiang sttrigraphic section in Dongjiang River valley in the south of the Nanling Mountains is a set of red sandy sediments.Measured by thermoluminescence (TL) dating, it was found to be formed in MIS2-9,500±800 yr to 19,600±1,800 yr B.P. After analysis of the grain sizes of the 16 samples (LJ3-100 to LJ3-85) in this layer, it was discovered that (1) The contents of each grain group in different samples are similar. (2) The values of Md, Mz,σ,Sk and Kg vary from LJ3-100 to LJ3-85 in a narrow range. (3) The segments of each sample in the accumulative curves extend parallel with similar slopes. All the three aspects reveal the Aeolian characteristics of Layer LJ3.Therefore, it is thought that Layer LJ3 consists of red sandy sediments formed in MIS2 in the south of Nanling Mountain, which reflects the arid climate at that time.

  9. Combined Effects of Dam Removal and Past Sediment Mining on a Relatively Large Lowland Sandy Gravelly Bed River (Vienne River, France).

    Science.gov (United States)

    Rodrigues, S.; Ursache, O.; Bouchard, J. P.; Juge, P.

    2014-12-01

    Dam removal is of growing interest for the management of sediment fluxes, morphological evolution and ecological restoration of rivers. If dam removal experiments are well documented for small streams, examples of lowland and large rivers are scarce. We present the morphological response of a relatively large lowland river (Vienne River, France) to a dam removal. The objective is to understand and quantify the morphological adaptation on a reach of 50 km and over 15 years associated with the dam removal and the presence of ancient sand pits located along the riverbed. This study is based on field data collected during 7 surveys performed between 1998 and 2013. This dataset focuses on bed geometry, sediment grain size, and bedload fluxes. It was combined with a 1D numerical model to assess flow dynamics and sediment transport before and after dam removal. Results show that dam removal triggered both regressive and progressive erosions and that discharges higher than 100 m3.s-1 were sufficient to erode the sandy sediments trapped by the dam whereas gravels were mobilised for discharges higher than 300 m3.s-1. Since 1999, large bedload sediment waves coming from upstream migrated downstream at an average celerity of 2.2 km.year-1 and were trapped by three ancient sand pits located downstream. Some of these pits constitute efficient sediment traps even 15 years after dam removal. As a result, between 2002 and 2013, the slope of the river bed adjusted gently and observed morphological processes were minors compared with the time period between 1998 and 2002.

  10. Assessing the impact of Hurricanes Irene and Sandy on the morphology and modern sediment thickness on the inner continental shelf offshore of Fire Island, New York

    Science.gov (United States)

    Schwab, William C.; Baldwin, Wayne E.; Denny, Jane F.

    2016-01-15

    This report documents the changes in seabed morphology and modern sediment thickness detected on the inner continental shelf offshore of Fire Island, New York, before and after Hurricanes Irene and Sandy made landfall. Comparison of acoustic backscatter imagery, seismic-reflection profiles, and bathymetry collected in 2011 and in 2014 show that sedimentary structures and depositional patterns moved alongshore to the southwest in water depths up to 30 meters during the 3-year period. The measured lateral offset distances range between about 1 and 450 meters with a mean of 20 meters. The mean distances computed indicate that change tended to decrease with increasing water depth. Comparison of isopach maps of modern sediment thickness show that a series of shoreface-attached sand ridges, which are the dominant sedimentary structures offshore of Fire Island, migrated toward the southwest because of erosion of the ridge crests and northeast-facing flanks as well as deposition on the southwest-facing flanks and in troughs between individual ridges. Statistics computed suggest that the modern sediment volume across the about 81 square kilometers of common sea floor mapped in both surveys decreased by 2.8 million cubic meters, which is a mean change of –0.03 meters, which is smaller than the resolution limit of the mapping systems used.

  11. Three perspectives on bedload transport at a sandy gravel beach (Advocate Harbour, Nova Scotia) with focus on sediment properties

    Science.gov (United States)

    Stark, N.; Hay, A. E.; Guest, T.; Hatcher, M. G.; Cheel, R. A.; Barclay, D. J.; Zedel, L. J.; Lake, C. B.

    2012-12-01

    Bedload transport is the major transport mode for coarse sediment in coastal zones. Understanding its mechanisms requires knowledge of the driving force (hydrodynamics), the stabilizing force (sediment properties), and the bed characteristics (bed roughness, bed slope, bedforms). During a 3-week-long field experiment at Advocate Beach, Nova Scotia, bedload transport was targeted from three perspectives: (i) The water column: using a new acoustic Doppler profiler (MFDop), 3D flow velocities were monitored to assess bed shear stress over a range of conditions. Additionally, sediment concentrations close to the bed (~10 cm) were determined by water sampling under calm conditions (0.15-0.6 g/l) and within the shorebreak (1-50 g/l). (ii) The bed: rotary sonars were used to observe the development of ripples and bed elevation change as a measure of ongoing sediment transport. Also, the net displacement of 20 marked cobbles on the seabed surface was measured, revealing significant changes in transport direction and distance (ranging from 0 to 50 m). (iii) The sediment properties: grain size ranged from medium sand to small cobbles. The finer-grained particles were rounded, but showed an elliptic to plate-like shape. Grain size distributions varied significantly across the shoreface as well as under different hydrodynamic conditions. Observed beach cusps were strongly sorted (coarse pebbles at the horns, coarse sand in the bays). Direct shear tests were carried out to determine peak shear strengths of the sediment and friction angles. Peak shear strengths under low normal stress (0.47 kPa) can be compared best to surficial sediment conditions, and did not exceed 9 kPa in the case of the sands. The sediment showed a surprisingly strong dilative behavior during shearing and high friction angles considering the grain size, the low load and low density conditions during the tests. Thus, grain shape and the particle re-organization under shearing played important roles. Finally

  12. Laboratory investigations on the role of sediment surface and ground water chemistry in transport of bacteria through a contaminated Sandy Aquifer

    Science.gov (United States)

    Scholl, M.A.; Harvey, R.W.

    1992-01-01

    The effects of pH and sediment surface characteristics on sorption of indigenous groundwater bacteria were determined using contaminated and uncontaminated aquifer material from Cape Cod, MA. Over the pH range of the aquifer (5-7), the extent of bacterial sorption onto sediment in uncontaminated groundwater was strongly pH-dependent, but relatively pH-insensitive in contaminated groundwater from the site. Bacterial sorption was also affected by the presence of oxyhydroxide coatings (iron, aluminum, and manganese). Surface coating effects were most pronounced in uncontaminated groundwater (pH 6.4 at 10??C). Desorption of attached bacteria (up to 14% of the total number of labeled cells added) occurred in both field and laboratory experiments upon adjustment of groundwater to pH 8. The dependence of bacterial sorption upon environmental conditions suggests that bacterial immobilization could change substantially over relatively short distances in contaminated, sandy aquifers and that effects caused by changes in groundwater geochemistry can be significant.

  13. Environmental change indicated by grain-size variations and trace elements: An example from the sandy-loess sediments from the Doroshivtsy site (Ukraine)

    Science.gov (United States)

    Lehmkuhl, Frank; Schulte, Philipp; Loibl, Christa; Klasen, Nicole; Hauck, Thomas; Kels, Holger

    2014-05-01

    The recently discovered loess section of Doroshivtsy became famous due to archeological findings of the Gravettian. The profile represents a about 9 m sequence of sandy loess, intercalated by more humic horizons. It is situated in a flat gully and at an undercut slope of the Dniester River close to the village Doroshivtsy in the south-western Ukraine. Radiocarbon dating and luminescence ages are conclusive within the expected age range of the Gravettian period (22-28 ka). The loess section is composed mainly of sandy silt and covers the time span from about 26 to 16 ka. This is one of the very few sections in Europe which provides a high resolution sedimentary record including prehistoric finds of the cooling maximum of the last glacial cycle. Based on the field description and the grain size distribution obtained by Laser Diffraction Particle Size Analyzer (Beckman Coulter LS 13 320 PIDS), the profile can be divided into three main genetic units representing changes during the deposition. The upper part (1-3 m) of the profile is characterized by aeolian loess and sand deposition intercalated with a few gravel lines. The middle part (3-6.5 m) of the profile is influenced by aeolian, denudative and weak soil forming processes. The lower part (6.5-9 m) of the section represents a combination of aeolian loess, re-deposited slope material. Additionally, the whole part is affected by hydromorphic conditions. As the sediment is rather homogeneous sandy silt U-ratio and GSI did not show any distinct variations. However, calculations with different grain-size ratios show that a fine silt to fine sand ratio (SiS-ratio) of 3.5 to 8.1 µm and 69.6 to 161.1 µm provide clear peaks. These variations of the SiS-ratio represent environmental changes which are also observed by structures and weak soil formations in the section during field work and fit also to the different archeological layers. In addition, geochemical analysis show comparable results to the SiS-ratio and provide

  14. Adsorption and desorption of arsenate on sandy sediments from contaminated and uncontaminated saturated zones: Kinetic and equilibrium modeling.

    Science.gov (United States)

    Hafeznezami, Saeedreza; Zimmer-Faust, Amity G; Dunne, Aislinn; Tran, Tiffany; Yang, Chao; Lam, Jacquelyn R; Reynolds, Matthew D; Davis, James A; Jay, Jennifer A

    2016-08-01

    Application of empirical models to adsorption of contaminants on natural heterogeneous sorbents is often challenging due to the uncertainty associated with fitting experimental data and determining adjustable parameters. Sediment samples from contaminated and uncontaminated portions of a study site in Maine, USA were collected and investigated for adsorption of arsenate [As(V)]. Two kinetic models were used to describe the results of single solute batch adsorption experiments. Piecewise linear regression of data linearized to fit pseudo-first order kinetic model resulted in two distinct rates and a cutoff time point of 14-19 h delineating the biphasic behavior of solute adsorption. During the initial rapid adsorption stage, an average of 60-80% of the total adsorption took place. Pseudo-second order kinetic models provided the best fit to the experimental data (R(2) > 0.99) and were capable of describing the adsorption over the entire range of experiments. Both Langmuir and Freundlich isotherms provided reasonable fits to the adsorption data at equilibrium. Langmuir-derived maximum adsorption capacity (St) of the studied sediments ranged between 29 and 97 mg/kg increasing from contaminated to uncontaminated sites. Solid phase As content of the sediments ranged from 3.8 to 10 mg/kg and the As/Fe ratios were highest in the amorphous phase. High-pH desorption experiments resulted in a greater percentage of solid phase As released into solution from experimentally-loaded sediments than from the unaltered samples suggesting that As(V) adsorption takes place on different reversible and irreversible surface sites.

  15. Intrinsic rates of petroleum hydrocarbon biodegradation in Gulf of Mexico intertidal sandy sediments and its enhancement by organic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mortazavi, Behzad, E-mail: bmortazavi@ua.edu [University of Alabama, Department of Biological Sciences, Box 870344, University of Alabama, Tuscaloosa, AL 35487 (United States); Dauphin Island Sea Lab, 101 Bienville Boulevard, Dauphin Island, AL, 36528 (United States); Horel, Agota [University of Alabama, Department of Biological Sciences, Box 870344, University of Alabama, Tuscaloosa, AL 35487 (United States); Dauphin Island Sea Lab, 101 Bienville Boulevard, Dauphin Island, AL, 36528 (United States); Beazley, Melanie J.; Sobecky, Patricia A. [University of Alabama, Department of Biological Sciences, Box 870344, University of Alabama, Tuscaloosa, AL 35487 (United States)

    2013-01-15

    The rates of crude oil degradation by the extant microorganisms in intertidal sediments from a northern Gulf of Mexico beach were determined. The enhancement in crude oil degradation by amending the microbial communities with marine organic matter was also examined. Replicate mesocosm treatments consisted of: (i) controls (intertidal sand), (ii) sand contaminated with crude oil, (iii) sand plus organic matter, and (iv) sand plus crude oil and organic matter. Carbon dioxide (CO{sub 2}) production was measured daily for 42 days and the carbon isotopic ratio of CO{sub 2} (δ{sup 13}CO{sub 2}) was used to determine the fraction of CO{sub 2} derived from microbial respiration of crude oil. Bacterial 16S rRNA clone library analyses indicated members of Actinobacteria, Bacteroidetes, and Chloroflexi occurred exclusively in control sediments whereas Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Firmicutes occurred in both control and oil contaminated sediments. Members of the hydrocarbon-degrading genera Hydrocarboniphaga, Pseudomonas, and Pseudoxanthomonas were found primarily in oil contaminated treatments. Hydrocarbon mineralization was 76% higher in the crude oil amended with organic matter treatment compared to the rate in the crude oil only treatment indicating that biodegradation of crude oil in the intertidal zone by an extant microbial community is enhanced by input of organic matter.

  16. Formation of natural gas hydrates in marine sediments 1. Conceptual model of gas hydrate growth conditioned by host sediment properties

    Science.gov (United States)

    Clennell, M.B.; Hovland, M.; Booth, J.S.; Henry, P.; Winters, W.J.

    1999-01-01

    The stability of submarine gas hydrates is largely dictated by pressure and temperature, gas composition, and pore water salinity. However, the physical properties and surface chemistry of deep marine sediments may also affect the thermodynamic state, growth kinetics, spatial distributions, and growth forms of clathrates. Our conceptual model presumes that gas hydrate behaves in a way analogous to ice in a freezing soil. Hydrate growth is inhibited within fine-grained sediments by a combination of reduced pore water activity in the vicinity of hydrophilic mineral surfaces, and the excess internal energy of small crystals confined in pores. The excess energy can be thought of as a "capillary pressure" in the hydrate crystal, related to the pore size distribution and the state of stress in the sediment framework. The base of gas hydrate stability in a sequence of fine sediments is predicted by our model to occur at a lower temperature (nearer to the seabed) than would be calculated from bulk thermodynamic equilibrium. Capillary effects or a build up of salt in the system can expand the phase boundary between hydrate and free gas into a divariant field extending over a finite depth range dictated by total methane content and pore-size distribution. Hysteresis between the temperatures of crystallization and dissociation of the clathrate is also predicted. Growth forms commonly observed in hydrate samples recovered from marine sediments (nodules, and lenses in muds; cements in sands) can largely be explained by capillary effects, but kinetics of nucleation and growth are also important. The formation of concentrated gas hydrates in a partially closed system with respect to material transport, or where gas can flush through the system, may lead to water depletion in the host sediment. This "freeze-drying" may be detectable through physical changes to the sediment (low water content and overconsolidation) and/or chemical anomalies in the pore waters and metastable

  17. Separation of Clay Minerals from Host Sediments Using Cation Exchange Resins

    Institute of Scientific and Technical Information of China (English)

    I.S. Ismael; H.M. Baioumy

    2003-01-01

    Classic physical and chemical treatments applied to separating clay minerals from the host sediments are often difficult or aggressive for clay minerals. A technique using cation exchange resins (amberlite IRC-50H and amberlite IR-120) is used to separate clay minerals from the host sediments. The technique is based on the exchange of cations in the minerals that may be associated clay minerals in sediments,such as Ca and Mg from dolomite; Ca from calcite,gypsum and francolite with cations carried by resin radicals. The associated minerals such as gypsum,calcite,dolomite and francolite are removed in descending order. Separation of clay minerals using cation exchange resins is less aggressive than that by other classic treatments.The efficiency of amberlite IRC-50H in the removal of associated minerals is greater than that of amberlite IR-120.

  18. Sediment-hosted gold deposits of the world: database and grade and tonnage models

    Science.gov (United States)

    Berger, Vladimir I.; Mosier, Dan L.; Bliss, James D.; Moring, Barry C.

    2014-01-01

    All sediment-hosted gold deposits (as a single population) share one characteristic—they all have disseminated micron-sized invisible gold in sedimentary rocks. Sediment-hosted gold deposits are recognized in the Great Basin province of the western United States and in China along with a few recognized deposits in Indonesia, Iran, and Malaysia. Three new grade and tonnage models for sediment-hosted gold deposits are presented in this paper: (1) a general sediment-hosted gold type model, (2) a Carlin subtype model, and (3) a Chinese subtype model. These models are based on grade and tonnage data from a database compilation of 118 sediment-hosted gold deposits including a total of 123 global deposits. The new general grade and tonnage model for sediment-hosted gold deposits (n=118) has a median tonnage of 5.7 million metric tonnes (Mt) and a gold grade of 2.9 grams per tonne (g/t). This new grade and tonnage model is remarkable in that the estimated parameters of the resulting grade and tonnage distributions are comparable to the previous model of Mosier and others (1992). A notable change is in the reporting of silver in more than 10 percent of deposits; moreover, the previous model had not considered deposits in China. From this general grade and tonnage model, two significantly different subtypes of sediment-hosted gold deposits are differentiated: Carlin and Chinese. The Carlin subtype includes 88 deposits in the western United States, Indonesia, Iran, and Malaysia, with median tonnage and grade of 7.1 Mt and 2.0 g/t Au, respectively. The silver grade is 0.78 g/t Ag for the 10th percentile of deposits. The Chinese subtype represents 30 deposits in China, with a median tonnage of 3.9 Mt and medium grade of 4.6 g/t Au. Important differences are recognized in the mineralogy and alteration of the two sediment-hosted gold subtypes such as: increased sulfide minerals in the Chinese subtype and decalcification alteration dominant in the Carlin type. We therefore

  19. Formation of natural gas hydrates in marine sediments. Gas hydrate growth and stability conditioned by host sediment properties

    Science.gov (United States)

    Clennell, M.B.; Henry, P.; Hovland, M.; Booth, J.S.; Winters, W.J.; Thomas, M.

    2000-01-01

    The stability conditions of submarine gas hydrates (methane clathrates) are largely dictated by pressure, temperature, gas composition, and pore water salinity. However, the physical properties and surface chemistry of the host sediments also affect the thermodynamic state, growth kinetics, spatial distributions, and growth forms of clathrates. Our model presumes that gas hydrate behaves in a way analogous to ice in the pores of a freezing soil, where capillary forces influence the energy balance. Hydrate growth is inhibited within fine-grained sediments because of the excess internal phase pressure of small crystals with high surface curvature that coexist with liquid water in small pores. Therefore, the base of gas hydrate stability in a sequence of fine sediments is predicted by our model to occur at a lower temperature, and so nearer to the seabed than would be calculated from bulk thermodynamic equilibrium. The growth forms commonly observed in hydrate samples recovered from marine sediments (nodules, sheets, and lenses in muds; cements in sand and ash layers) can be explained by a requirement to minimize the excess of mechanical and surface energy in the system.

  20. Sand on the move: Post Hurricane Sandy analysis of the coastal sediment budget and bedform migration at Jones Inlet, Long Island, NY

    Science.gov (United States)

    Bales, M. K.; Goff, J. A.; Austin, J. A.; Flood, R. D.; Christensen, B. A.; Browne, C. M.; Saustrup, S.

    2013-12-01

    Hurricane Sandy struck the Northeast coast of the United States on October 29, 2012. Although sustained winds were downgraded to ~70 kts upon landfall, the vast area of the storm along with the direction of impact resulted in major storm-surge flooding and damage, as well as significant changes to the morphology of the coast-line, altering the characteristics of major barrier islands, inlets, and estuaries. A January 2013 post-storm survey aboard the R/V Pritchard, conducted by the University of Texas Institute for Geophysics, Stony Brook University, and Adelphi University, sought to investigate the impact of this post-tropical cyclone on the southwestern coast of Long Island, NY which sustained storm surges of up to 4 m above normal sea level. The objective of this project is to gain insight on the sedimentological volume changes and bathymetrical alterations made on the seafloor within Jones Inlet and the immediate estuaries behind Jones Beach and Long Beach Island. By studying these changes we hope to gain a better understanding of how large cyclonic storms alter sediment volumes and seafloor topography within major inlets and estuarine systems. These modifications can be observed in post-storm multibeam swath bathymetry and backscatter when compared to similar pre-storm data collected in 2010 by Stony Brook University. Post-storm CHIRP seismic reflection data were also collected, in order to define stratigraphic geometries, as well as grab samples to determine grain size distributions and ground truth for the backscatter data. The acoustic reflections imaged in the CHIRP data allow basal reflectors and dominate horizons to be traced throughout the inlet and estuaries. Our analysis focuses on (1) defining and quantifying areas of deposition and erosion from before-and-after bathymetry data; (2) comparing bedform patterns and grain size distributions from before-and-after backscatter and grab sample analysis; and (3) defining stratal geometries of the shallow

  1. Critical elements in sediment-hosted deposits (clastic-dominated Zn-Pb-Ag, Mississippi Valley-type Zn-Pb, sedimentary rock-hosted Stratiform Cu, and carbonate-hosted Polymetallic Deposits): A review: Chapter 12

    Science.gov (United States)

    Marsh, Erin; Hitzman, Murray W.; Leach, David L.

    2016-01-01

    Some sediment-hosted base metal deposits, specifically the clastic-dominated (CD) Zn-Pb deposits, carbonate-hosted Mississippi Valley-type (MVT) deposits, sedimentary-rock hosted stratiform copper deposits, and carbonate-hosted polymetallic (“Kipushi type”) deposits, are or have been important sources of critical elements including Co, Ga, Ge, and Re. The generally poor data concerning trace element concentrations in these types of sediment-hosted ores suggest that there may be economically important concentrations of critical elements yet to be recognized.

  2. Potentially bioavailable iron delivery by iceberg-hosted sediments and atmospheric dust to the polar oceans

    Science.gov (United States)

    Raiswell, Robert; Hawkings, Jon R.; Benning, Liane G.; Baker, Alex R.; Death, Ros; Albani, Samuel; Mahowald, Natalie; Krom, Michael D.; Poulton, Simon W.; Wadham, Jemma; Tranter, Martyn

    2016-07-01

    Iceberg-hosted sediments and atmospheric dust transport potentially bioavailable iron to the Arctic and Southern oceans as ferrihydrite. Ferrihydrite is nanoparticulate and more soluble, as well as potentially more bioavailable, than other iron (oxyhydr)oxide minerals (lepidocrocite, goethite, and hematite). A suite of more than 50 iceberg-hosted sediments contain a mean content of 0.076 wt % Fe as ferrihydrite, which produces iceberg-hosted Fe fluxes ranging from 0.7 to 5.5 and 3.2 to 25 Gmoles yr-1 to the Arctic and Southern oceans respectively. Atmospheric dust (with little or no combustion products) contains a mean ferrihydrite Fe content of 0.038 wt % (corresponding to a fractional solubility of ˜ 1 %) and delivers much smaller Fe fluxes (0.02-0.07 Gmoles yr-1 to the Arctic Ocean and 0.0-0.02 Gmoles yr-1 to the Southern Ocean). New dust flux data show that most atmospheric dust is delivered to sea ice where exposure to melting/re-freezing cycles may enhance fractional solubility, and thus fluxes, by a factor of approximately 2.5. Improved estimates for these particulate sources require additional data for the iceberg losses during fjord transit, the sediment content of icebergs, and samples of atmospheric dust delivered to the polar regions.

  3. Bibliography of sandy beaches and sandy beach organisms on the African continent

    CSIR Research Space (South Africa)

    Bally, R

    1986-01-01

    Full Text Available This bibliography covers the literature relating to sandy beaches on the African continent and outlying islands. The bibliography lists biological, chemical, geographical and geological references and covers shallow marine sediments, surf zones off...

  4. Sulfur- and oxygen-isotopes in sediment-hosted stratiform barite deposits

    Science.gov (United States)

    Johnson, C.A.; Emsbo, P.; Poole, F.G.; Rye, R.O.

    2009-01-01

    Sulfur- and oxygen-isotope analyses have been obtained for sediment-hosted stratiform barite deposits in Alaska, Nevada, Mexico, and China to examine the environment of formation of this deposit type. The barite is contained in sedimentary sequences as old as Late Neoproterozoic and as young as Mississippian. If previously published data for other localities are considered, sulfur- and oxygen-isotope data are now available for deposits spanning a host-rock age range of Late Neoproterozoic to Triassic. On a ??34S versus ??18O diagram, many deposits show linear or concave-upward trends that project down toward the isotopic composition of seawater sulfate. The trends suggest that barite formed from seawater sulfate that had been isotopically modified to varying degrees. The ??34S versus ??18O patterns resemble patterns that have been observed in the modern oceans in pore water sulfate and water column sulfate in some anoxic basins. However, the closest isotopic analog is barite mineralization that occurs at fluid seeps on modern continental margins. Thus the data favor genetic models for the deposits in which barium was delivered by seafloor seeps over models in which barium was delivered by sedimentation of pelagic organisms. The isotopic variations within the deposits appear to reflect bacterial sulfate reduction operating at different rates and possibly with different electron donors, oxygen isotope exchange between reduction intermediates and H2O, and sulfate availability. Because they are isotopically heterogeneous, sediment-hosted stratiform barite deposits are of limited value in reconstructing the isotopic composition of ancient seawater sulfate.

  5. Sediment-hosted/orogenic gold mineral systems exploration using PALSAR remote sensing data in Peninsular Malaysia

    Science.gov (United States)

    Beiranvand Pour, Amin; Hashim, Mazlan

    2016-06-01

    The Bentong-Raub Suture Zone (BRSZ) is genetically related to the sediment-hosted/orogenic gold deposits associated with the major lineaments and form-lines in the Central Gold Belt of Peninsular Malaysia. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to analyse major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and form-lines in the BRSZ, as well as its implications for sediment-hosted/orogenic gold exploration in tropical environments. The pervasive array of N-S faults in the study area and surrounding terrain is mainly linked to the N-S trending of the BRSZ Suture Zone. N-S striking lineaments are often cut by younger NE-SW and NW-SE-trending lineaments. Three generations of folding event have been discerned from remote sensing structural analysis. Gold mineralized trends lineaments are associated with the intersection of N-S, NE-SW, NNW-SSE and ESE-WNW faults and curvilinear features in shearing and alteration zones. Compressional tectonics structures such as NW-SE trending thrust, ENE-WSW oriented faults in mylonite and phyllite, recumbent folds and asymmetric anticlines in argillite are high potential zones for gold prospecting.

  6. Hurricane Sandy and earthquakes

    OpenAIRE

    MAVASHEV BORIS; MAVASHEV IGOR

    2013-01-01

    Submit for consideration the connection between formation of a hurricane Sandy and earthquakes. As a rule, weather anomalies precede and accompany earthquakes. The hurricane Sandy emerged 2 days prior to strong earthquakes that occurred in the area. And the trajectory of the hurricane Sandy matched the epicenter of the earthquakes. Possibility of early prediction of natural disasters will minimize the moral and material damage.

  7. Reactive and unreactive iron minerals hosting arsenic within seasonal wetland sediments of the Mekong Delta

    Science.gov (United States)

    Stuckey, J.; Schaefer, M.; Lezama, J.; Dittmar, J.; Fendorf, S.

    2013-12-01

    Millions of people in the deltaic regions of S/SE Asia regularly consume arsenic contaminated groundwater. Within the Mekong Delta of Cambodia, for example, arsenic persists within the groundwater despite being flushed by several pore volumes of recharge. The identity and reactivity of the minerals contributing to the persistence of arsenic in the deltaic aquifers remain elusive. Here we seek to define the molecular form of the arsenic and its host phases along defined flow paths in seasonally saturated wetlands: i) a grassland flooded for ~ 3 - 4 months of the year (Grassland) and ii) an abandoned river channel saturated for ~ 5 - 6 months (Oxbow). Sediment cores were retrieved by pounding aluminum cores into a fresh profile exposed by successive excavation. The cores were sealed with melted wax in the field and stored at 4 °C until processed. Depths of 0.2 to 6 m were sampled at the Grassland site and 0.2 to 4 m at the Oxbow site. Sediments were dried under 95%N2/5%H2 atmosphere. A 1 M HCl extraction dissolving the 'reactive' iron (predominantly poorly crystalline iron oxides) solubilized 3 - 7 % of the total iron in the Grassland site and 8 - 41 % in the Oxbow site. A citrate-bicarbonate-dithionite (CBD) extraction was performed to extract reducible iron (predominantly iron oxides), accounting for 35 - 50 % of the total iron in the Grassland site and 27 - 44 % in the Oxbow site. Correspondingly, least squares fitting of k3 - weighted chi(k) iron extended X-ray absorption fine structure (EXAFS) spectra showed that goethite and hematite together comprised 34 - 50 % of the iron mineralogy in the mineral sediments of the Grassland site and 24 - 38 % of those in the Oxbow site. The remaining iron minerals present were predominantly silicates. Iron EXAFS spectra were obtained for the post-CBD extracted sediments, theoretically containing only non-reducible iron. Least squares fitting of the bulk (pre-CBD extracted) sediments was performed a second time with the

  8. Short Communication Energy and ash contents of sandy beach ...

    African Journals Online (AJOL)

    macrofauna found on three exposed sandy beaches on the west coast ... that they often form the predominant shore type (Bally,. McQuaid ... their sediments are given in Table I. Animals ..... The biochemical composition of the tropical intertida1 ...

  9. Interstitial meiofauna of Namib sandy beaches

    African Journals Online (AJOL)

    1988-03-16

    Mar 16, 1988 ... sandy beaches on the Namibian coast, Langstrand and Cape Cross. A transverse ... prominent in the mid-shore at Cape Cross but occurred in low numbers at Langstrand , where archiannelids ... Koop (1983) recorded the faunal composition of local .... four replicate sediment cores were taken at 15 cm.

  10. The Light-Field of Microbenthic Communities - Radiance Distribution and Microscale Optics of Sandy Coastal Sediments Rid A-1977-2009

    DEFF Research Database (Denmark)

    KUHL, M.; JØRGENSEN, BB

    1994-01-01

    The light field in coastal sediments was investigated at a spatial resolution of 0.2-0.5 mm by spectral measurements (450-850 nm) of field radiance and scalar irradiance using fiber-optic microprobes. Depth profiles of field radiance were measured with radiance microprobes at representative angles...... with the scalar irradiance measured directly by a fiber-optic scalar irradiance microprobe. Close to the sediment surface, the light field was highly anisotropic, dominated by incident collimated light, and the scalar irradiance reached a maximum of 200% of incident scalar irradiance. Below the sediment surface...

  11. Processing of 13C-labelled phytoplankton in a fine-grained sandy-shelf sediment (North Sea): relative importance of different macrofauna species

    DEFF Research Database (Denmark)

    Kamp, Anja; Witte, Ursula

    2005-01-01

    by additional laboratory experiments on the role of the dominant macrofauna organism, the bivalve Fabulina fabula (Bivalvia: Tellinidae), for particulate organic matter subduction to deeper sediment layers. The specific uptake of algal 13C by macrofauna organisms was visible after 12 h and constantly increased...... carbon processing. Predatory macrofauna organisms like Nephtys spp. (Polychaeta: Nephtyidae) also quickly became labelled. The rapid subduction of fresh organic matter by F. fabula down to ca. 4 to 7 cm sediment depth could be demonstrated, and it is suggested that entrainment by macrofauna in this fine...

  12. Sediment Transport and Infilling of a Borrow Pit on an Energetic Sandy Ebb Tidal Delta Offshore of Hilton Head Island, South Carolina

    Science.gov (United States)

    Wren, A.; Xu, K.; Ma, Y.; Sanger, D.; Van Dolah, R.

    2014-12-01

    Bottom-mounted instrumentation was deployed at two sites on an ebb tidal delta to measure hydrodynamics, sediment transport, and seabed elevation. One site ('borrow site') was 2 km offshore and used as a dredging site for beach nourishment of nearby Hilton Head Island in South Carolina, and the other site ('reference site') was 10 km offshore and not directly impacted by the dredging. In-situ time-series data were collected during two periods after the dredging: March 15 - June 12, 2012('spring') and August 18 - November 18, 2012 ('fall'). At the reference site directional wave spectra and upper water column current velocities were measured, as well as high-resolution current velocity profiles and suspended sediment concentration profiles in the Bottom Boundary Layer (BBL). Seabed elevation and small-scale seabed changes were also measured. At the borrow site seabed elevation and near-bed wave and current velocities were collected using an Acoustic Doppler Velocimeter. Throughout both deployments bottom wave orbital velocities ranged from 0 - 110 m/s at the reference site. Wave orbital velocities were much lower at the borrow site ranging from 10-20 cm/s, as wave energy was dissipated on the extensive and rough sand banks before reaching the borrow site. Suspended sediment concentrations increased throughout the BBL when orbital velocities increased to approximately 20 cm/s. Sediment grain size and critical shear stresses were similar at both sites, therefore, re-suspension due to waves was less frequent at the borrow site. However, sediment concentrations were highly correlated with the tidal cycle at both sites. Semidiurnal tidal currents were similar at the two sites, typically ranging from 0 - 50 cm/s in the BBL. Maximum currents exceeded the critical shear stress and measured suspended sediment concentrations increased during the first hours of the tidal cycle when the tide switched to flood tide. Results indicate waves contributed more to sediment mobility at

  13. Carbonate Geochemistry of Marine Authigenic Carbonates and Host Sediments: Exploring Mineral Formation Pathways and Organic Preservation Potential in Modern Sediments

    Science.gov (United States)

    Smirnoff, M. N.; Loyd, S. J.

    2016-12-01

    Ancient authigenic dolomites (e.g., concretions) have been long studied in order to determine formation conditions and provide insight into shallow diagenetic environments. The formation of these dolomites is commonly attributed to the anaerobic microbial degradation of organic matter (a process that can increase the local pore water alkalinity), based on carbon isotope as well as other geochemical data. Authigenic dolomites also occur in modern, "still soft" sediments rich in organic matter. However, a comprehensive carbon isotopic characterization of these precipitates has yet to be conducted. Preliminary data show a wide range of δ13C values (about -11 to +12‰). Positive values that typify dolomites of the Gulf of California and the southwestern African margin indicate methanogenesis. Dolomites of the Peru margin and Cariaco Basin yield negative values that may represent a variety of organic matter degradation mechanisms. Regardless of specific mechanisms, organic matter degradation can promote authigenesis. Ultimately, mineralization encases primary sedimentary components and may act to preserve organic matter from subsequent degradation due to permeability reduction resulting from cementation. Concretionary carbonates have been found to preserve macro and micro fossils, metastable sedimentary grains, magnetic minerals, sedimentary structures, various specific organic compounds, and overmature organic matter exposed in outcrop. However, a similar protective relationship has not been demonstrated for disseminated, bulk organic matter in still-soft sediments. The study of these sediments 1) reveal the relationship between organic carbon degradation and authigenesis and 2) may provide insight into the potential of cementation to preserve organic matter during subsequent burial.

  14. Analyzing Hurricane Sandy

    Science.gov (United States)

    Convertino, Angelyn; Meyer, Stephan; Edwards, Becca

    2015-03-01

    Post-tropical Storm Sandy underwent extratropical transition shortly before making landfall in southern New Jersey October 29 2012. Data from this system was compared with data from Hurricane Ike (2008) which represents a classic hurricane with a clear eye wall and symmetry after landfall. Storm Sandy collided with a low pressure system coming in from the north as the hurricane made landfall on the US East coast. This contributed to Storm Sandy acting as a non-typical hurricane when it made landfall. Time histories of wind speed and wind direction were generated from data provided by Texas Tech's StickNet probes for both storms. The NOAA Weather and Climate program were used to generate radar loops of reflectivity during the landfall for both storms; these loops were compared with time histories for both Ike and Sandy to identify a relationship between time series data and storm-scale features identified on radar.

  15. Maps showing bathymetry and modern sediment thickness on the inner continental shelf offshore of Fire Island, New York, pre-Hurricane Sandy

    Science.gov (United States)

    Schwab, William C.; Denny, Jane F.; Baldwin, Wayne E.

    2014-01-01

    The U.S. Geological Survey mapped approximately 336 square kilometers of the lower shoreface and inner continental shelf offshore of Fire Island, New York, in 2011 by using interferometric sonar and high-resolution chirp seismic-reflection systems. This report presents maps of bathymetry, acoustic backscatter, the coastal plain unconformity, the Holocene marine transgressive surface, and modern sediment thickness. These spatial data support research on the Quaternary evolution of the Fire Island coastal system and provide baseline information for research on coastal processes along southern Long Island.

  16. Processing of 13C-labelled phytoplankton in a fine-grained sandy-shelf sediment (North Sea): relative importance of different macrofauna species

    DEFF Research Database (Denmark)

    Kamp, Anja; Witte, Ursula

    2005-01-01

    during the incubation periods. F. fabula, a facultative (surface) deposit- and suspension-feeder, Lanice conchilega (Polychaeta: Terebellidae), a suspension-feeder and the (sur- face) deposit-feeder Echinocardium cordatum (Echinodermata: Spatangidae) were responsible for the majority of macrofaunal...... carbon processing. Predatory macrofauna organisms like Nephtys spp. (Polychaeta: Nephtyidae) also quickly became labelled. The rapid subduction of fresh organic matter by F. fabula down to ca. 4 to 7 cm sediment depth could be demonstrated, and it is suggested that entrainment by macrofauna in this fine...

  17. Comparison of Archaeal and Bacterial Diversity in Methane Seep Carbonate Nodules and Host Sediments, Eel River Basin and Hydrate Ridge, USA.

    Science.gov (United States)

    Mason, Olivia U; Case, David H; Naehr, Thomas H; Lee, Raymond W; Thomas, Randal B; Bailey, Jake V; Orphan, Victoria J

    2015-10-01

    Anaerobic oxidation of methane (AOM) impacts carbon cycling by acting as a methane sink and by sequestering inorganic carbon via AOM-induced carbonate precipitation. These precipitates commonly take the form of carbonate nodules that form within methane seep sediments. The timing and sequence of nodule formation within methane seep sediments are not well understood. Further, the microbial diversity associated with sediment-hosted nodules has not been well characterized and the degree to which nodules reflect the microbial assemblage in surrounding sediments is unknown. Here, we conducted a comparative study of microbial assemblages in methane-derived authigenic carbonate nodules and their host sediments using molecular, mineralogical, and geochemical methods. Analysis of 16S rRNA gene diversity from paired carbonate nodules and sediments revealed that both sample types contained methanotrophic archaea (ANME-1 and ANME-2) and syntrophic sulfate-reducing bacteria (Desulfobacteraceae and Desulfobulbaceae), as well as other microbial community members. The combination of geochemical and molecular data from Eel River Basin and Hydrate Ridge suggested that some nodules formed in situ and captured the local sediment-hosted microbial community, while other nodules may have been translocated or may represent a record of conditions prior to the contemporary environment. Taken together, this comparative analysis offers clues to the formation regimes and mechanisms of sediment-hosted carbonate nodules.

  18. Linking hydrothermal geochemistry to organismal physiology: physiological versatility in Riftia pachyptila from sedimented and basalt-hosted vents.

    Science.gov (United States)

    Robidart, Julie C; Roque, Annelys; Song, Pengfei; Girguis, Peter R

    2011-01-01

    Much of what is known regarding Riftia pachyptila physiology is based on the wealth of studies of tubeworms living at diffuse flows along the fast-spreading, basalt-hosted East Pacific Rise (EPR). These studies have collectively suggested that Riftia pachyptila and its chemoautotrophic symbionts are physiologically specialized, highly productive associations relying on hydrogen sulfide and oxygen to generate energy for carbon fixation, and the symbiont's nitrate reduction to ammonia for energy and biosynthesis. However, Riftia also flourish in sediment-hosted vents, which are markedly different in geochemistry than basalt-hosted systems. Here we present data from shipboard physiological studies and global quantitative proteomic analyses of Riftia pachyptila trophosome tissue recovered from tubeworms residing in the EPR and the Guaymas basin, a sedimented, hydrothermal vent field. We observed marked differences in symbiont nitrogen metabolism in both the respirometric and proteomic data. The proteomic data further suggest that Riftia associations in Guaymas may utilize different sulfur compounds for energy generation, may have an increased capacity for energy storage, and may play a role in degrading exogenous organic carbon. Together these data reveal that Riftia symbionts are far more physiologically plastic than previously considered, and that--contrary to previous assertions--Riftia do assimilate reduced nitrogen in some habitats. These observations raise new hypotheses regarding adaptations to the geochemical diversity of habitats occupied by Riftia, and the degree to which the environment influences symbiont physiology and evolution.

  19. Paleosols can promote root growth of recent vegetation - a case study from the sandy soil-sediment sequence Rakt, the Netherlands

    Science.gov (United States)

    Gocke, Martina I.; Kessler, Fabian; van Mourik, Jan M.; Jansen, Boris; Wiesenberg, Guido L. B.

    2016-10-01

    Soil studies commonly comprise the uppermost meter for tracing, e.g., soil development. However, the maximum rooting depth of various plants significantly exceeds this depth. We hypothesized that deeper parts of the soil, soil parent material and especially paleosols provide beneficial conditions in terms of, e.g., nutrient contents, thus supporting their utilization and exploitation by deep roots. We aimed to decipher the different phases of soil formation in Dutch drift sands and cover sands. The study site is located at Bedafse Bergen (southeastern Netherlands) in a 200-year-old oak stand. A recent Podzol developed on drift sand covering a Plaggic Anthrosol that was piled up on a relict Podzol on Late Glacial eolian cover sand. Root-free soil and sediment samples, collected in 10-15 cm depth increments, were subjected to a multi-proxy physical and geochemical approach. The Plaggic Anthrosol revealed low bulk density and high phosphorous and organic carbon contents, whereas the relict Podzol was characterized by high iron and aluminum contents. Frequencies of fine (diameter ≤ 2 mm) and medium roots (2-5 mm) were determined on horizontal levels and the profile wall for a detailed pseudo-three-dimensional insight. On horizontal levels, living roots were most abundant in the uppermost part of the relict Podzol with ca. 4450 and 220 m-2, significantly exceeding topsoil root abundances. Roots of oak trees thus benefited from the favorable growth conditions in the nutrient-rich Plaggic Anthrosol, whereas increased compactness and high aluminum contents of the relict Podzol caused a strong decrease of roots. The approach demonstrated the benefit of comprehensive root investigation to support interpretation of soil profiles, as fine roots can be significantly underestimated when quantified at the profile wall. The possible rooting of soil parent material and paleosols long after their burial confirmed recent studies on the potential influence of rooting to overprint

  20. Hurricane Sandy Washover Deposits on Southern Long Beach Island, NJ

    Science.gov (United States)

    Bishop, J. M.; Richmond, B. M.; Kane, H. H.; Lunghino, B.

    2015-12-01

    Hurricane Sandy washover deposits were investigated at Forsyth National Wildlife Refuge (FNWR) on Southern Long Beach Island, New Jersey in order to map deposit thickness and characterize the sedimentary deposits. FNWR was chosen as a field area because there has been relatively little anthropogenic shoreline modification since washover deposition from Hurricane Sandy. Sediment, elevation, and geophysical data were collected during the April 2015 field campaign, approximately two and a half years after the storm. Sediment deposit data included trenches, stratigraphic descriptions, bulk sediment samples, push cores, Russian cores, and photos. Computed tomography (CT) scanning was conducted on push cores in order to acquire high resolution imaging of density, grain size, and sedimentary structure. Profiles of washover elevation were measured using Differential GPS with Real Time Kinematic processing. Ground Penetrating Radar data was collected to image the depth of the deposit and identify sedimentary structures. These data sets are compared to pre- and post -Sandy lidar surveys in order to determine post-Sandy modification in the two and a half years following the hurricane. We compare sediment thickness and sedimentary characteristics to hurricane Sandy deposits elsewhere along the U.S. eastern seaboard and to tsunami deposits.

  1. Paleoproterozoic Sediment- hosted Gold Deposits in Eastern Liaoning, Northeast China: Implications for Gold Exploration

    Institute of Scientific and Technical Information of China (English)

    Yang Dejiang

    2001-01-01

    Gold deposits in eastern Liaoning, northeast China are hosted in the middle and upper parts of a Paleoproterozoic volcanic - sedimentary succession, which consists of interlayered carbonates and fine - grained clastics. This paper discusses the geological features of ore - bearing formations, ore- controlling structures and metallogenetic characteristics. Analysis of ore - controlling factors suggested that the schists from the Gaixian formatyion, syngenetic faults and ductile shear zones are principal ore controls over mineralization and thereafter indicators for gold exploration.

  2. Nanoscale Zirconium-(oxyhydr)oxide in Contaminated Sediments From Hanford, WA - A New Host for Uranium

    Science.gov (United States)

    Stubbs, J. E.; Elbert, D. C.; Veblen, L. A.; Zachara, J. M.; Davis, J. A.; Veblen, D. R.

    2008-12-01

    Zirconium-, uranium-, and copper-bearing wastes have leached from former disposal ponds into vadose zone sediments in the 300 Area at the Department of Energy's Hanford Site. Zirconium is enriched in the shallow portion of the vadose zone, and we have discovered an amorphous Zr-(oxyhydr)oxide that contains 16% of the total uranium budget (84.24 ppm) in one of the shallow samples. We have characterized the oxide using electron microprobe analysis (EMPA), a focused ion beam (FIB) instrument, and transmission electron microscopy (TEM). It occurs in fine-grained coatings found on lithic and mineral fragments in these sediments. The oxide is intimately intergrown with the phyllosilicates and other minerals of the coatings, and in places can be seen coating individual, nano-sized phyllosilicate mineral grains. Electron energy-loss spectroscopy (EELS) shows that the Zr-(oxyhydr)oxide has a P:Zr atomic ratio around 0.2, suggesting it is either intergrown with minor amounts of a Zr-phosphate or has adsorbed a significant amount of phosphate. This material has adsorbed or incorporated a substantial amount of uranium. Thus, understanding its nature is critical to predicting the long-term fate of U in the Hanford vadose zone. While the low-temperature uptake of U by Zr-(oxhydr)oxides and phosphates has been studied for several decades in laboratory settings, to our knowledge ours is the first report of such uptake in the field.

  3. Hopane, sterane and n-alkane distributions in shallow sediments hosting high arsenic groundwaters in Cambodia

    Energy Technology Data Exchange (ETDEWEB)

    Dongen, Bart E. van [School of Earth, Atmospheric and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)], E-mail: Bart.vanDongen@manchester.ac.uk; Rowland, Helen A.L.; Gault, Andrew G.; Polya, David A. [School of Earth, Atmospheric and Environmental Sciences, Williamson Research Centre for Molecular Environmental Science, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Bryant, Charlotte [NERC Radiocarbon Laboratory, Scottish Enterprise Technology Park, Rankine Avenue, East Kilbride G75 0QF (United Kingdom); Pancost, Richard D. [Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, School of Chemistry, Cantock' s Close, Bristol University, Bristol BS8 1TS (United Kingdom)

    2008-11-15

    The presence of elevated As in ground waters exploited for drinking water and irrigation in South-East Asia is causing serious impacts on human health. A key mechanism that causes the mobilization of As in these waters is microbially mediated reductive transformation of As-bearing Fe(III) hydrated oxides and the role of degradable organic matter (OM) in this process is widely recognized. A number of different types of OM that drive As release in these aquifers have been suggested, including petroleum derived hydrocarbons naturally seeping into shallow sediments from deeper thermally mature source rocks. However, the amount of information on the characteristics of the OM in South-East Asian aquifers is limited. Here the organic geochemical analyses of the saturated hydrocarbon fractions and radiocarbon analysis, of two additional sites in SE Asia are reported. The results show that the OM in a given sedimentary horizon likely derives from multiple sources including naturally occurring petroleum. The importance of naturally occurring petroleum as one of the sources was clearly indicated by the n-alkane CPI of approximately 1, the presence of an unresolved complex mixture, and hopane (dominated by 17{alpha}(H),21{beta}(H) hopanes) and sterane distribution patterns. The results also indicate that the OM in these aquifers varies tremendously in content, character and potential bioavailability. Furthermore, the presence of petroleum derived OM in sediments at both sites doubles the number of locations where their presence has been observed in association with As-rich, shallow aquifers, suggesting that the role of petroleum derived OM in microbially mediated As release might occur over a wider range of geographical locations than previously thought.

  4. Re-Os sulfide geochronology of the Red Dog sediment-hosted Zn-Pb-Ag deposit, Brooks Range, Alaska

    Science.gov (United States)

    Morelli, R.M.; Creaser, R.A.; Selby, D.; Kelley, K.D.; Leach, D.L.; King, A.R.

    2004-01-01

    The Red Dog sediment-hosted deposit in the De Long Mountains of northern Alaska is the largest Zn producer in the world. Main stage mineralization is characterized by massive sulfide ore and crosscutting subvertical veins. Although the vein mineralization is clearly younger than the massive ore, the exact temporal relationship between the two is unclear. Re-Os geochronology of pyrite is used to determine the absolute age of main stage ore at Red Dog. A 10-point isochron on both massive and vein pyrite yields an age of 338.3 ?? 5.8 Ma and is interpreted to represent the age of main stage ore. The Re-Os data indicate that both massive and vein ore types are coeval within the resolution of the technique. Formation of the Red Dog deposit was associated with extension along a passive continental margin, and therefore the Re-Os age of main stage ore constrains the timing of rifting as well as the age of the host sedimentary rocks. Sphalerite from both massive and vein ore yields imprecise ages and shows a high degree of scatter compared to pyrite. We suggest that the Re-Os systematics of sphalerite can be disturbed and that this mineral is not reliable for Re-Os geochronology. ?? 2004 by Economic Geology.

  5. Patterns of species richness in sandy beaches of South America

    African Journals Online (AJOL)

    Species richness of the intertidal macroinfauna of exposed sandy beaches around South America is reviewed in relation ... The middle shore is primsediment packing (expressed hae as penetrability of the ..... show significant changes in species composition with lati-.

  6. Fluid origin, gas fluxes and plumbing system in the sediment-hosted Salton Sea Geothermal System (California, USA)

    Science.gov (United States)

    Mazzini, Adriano; Svensen, Henrik; Etiope, Giuseppe; Onderdonk, Nathan; Banks, David

    2011-08-01

    The Salton Sea Geothermal System (California) is an easily accessible setting for investigating the interactions of biotic and abiogenic geochemical processes in sediment-hosted hydrothermal systems. We present new temperature data and the molecular and isotopic composition of fluids seeping at the Davis-Schrimpf seep field during 2003-2008. Additionally, we show the first flux data for CO 2 and CH 4 released throughout the field from focused vents and diffuse soil degassing. The emitted gases are dominated by CO 2 (~ 98%) and CH 4 (~ 1.5%). By combining δ 13C CO2 (as low as - 5.4‰) and δ 13C CH4 (- 32‰ to - 17.6‰) with 3He/ 4He (R/Ra > 6) and δD CH4 values (- 216‰ to - 150‰), we suggest, in contrast to previous studies, that CO 2 may have a significant Sub-Continental Mantle source, with minimal crustal contamination, and CH 4 seems to be a mixture of high temperature pyrolitic (thermogenic) and abiogenic gas. Water seeps show that δD and δ 18O increase proportionally with salinity (Total Dissolved Solids in g/L) ranging from 1-3 g/L (gryphons) to 145 g/L (hypersaline pools). In agreement with elemental analyses, the isotopic composition of the waters indicate a meteoric origin, modified by surface evaporation, with little or no evidence of deep fossil or magmatic components. Very high Cl/Br (> 3,000) measured at many seeping waters suggests that increased salinities result from dissolution of halite crusts near the seep sites. Gas flux measurements from 91 vents (pools and gryphons) give a conservative estimate of ~ 2,100 kg of CO 2 and 11.5 kg of CH 4 emitted per day. In addition soil degassing measured at 81 stations (20x20 m grid over 51,000 m 2) revealed that 7,310 kg/d CO 2 and 33 kg/d CH 4 are pervasively released to the atmosphere. These results emphasise that diffuse gas emission from soil can be dominant (~ 75%) even in hydrothermal systems with large and vigorous gas venting. Sediment-hosted hydrothermal systems may represent an

  7. Distribution and hosts of arsenic in a sediment core from the Chianan Plain in SW Taiwan: Implications on arsenic primary source and release mechanisms.

    Science.gov (United States)

    Yang, Huai-Jen; Lee, Chi-Yu; Chiang, Yu-Ju; Jean, Jiin-Shuh; Shau, Yen-Hong; Takazawa, Eiichi; Jiang, Wei-Teh

    2016-11-01

    High arsenic abundance of 50-700μg/L in the groundwater from the Chianan Plain in southwestern Taiwan is a well-known environmental hazard. The groundwater-associated sediments, however, have not been geochemically characterized, thus hindering a comprehensive understanding of arsenic cycling in this region. In this study, samples collected from a 250m sediment core at the centre of the Chianan Plain were analyzed for arsenic and TOC concentrations (N=158), constituent minerals (N=25), major element abundances (N=105), and sequential arsenic extraction (N=23). The arsenic data show a prevalence of >10mg/kg with higher concentrations of 20-50mg/kg concentrated at 60-80 and 195-210m. Arsenic was extracted mainly as an adsorbate on clay minerals, as a co-precipitate in amorphous iron oxyhydroxide, and as a structural component in clay minerals. Since the sediments consist mainly of quartz, chlorite, and illite, the correlations between arsenic concentration and abundances of K2O and MgO pinpoint illite and chlorite as the major arsenic hosts. The arsenic-total iron correlation reflects the role of chlorite along with the contribution from amorphous iron oxyhydroxide as indicated by arsenic extraction data. Organic matter is not the dominant arsenic host for low TOC content, low arsenic abundance extracted from it, and a relatively low R(2) of the arsenic-TOC correlation. The major constituent minerals in the sediments are the same as those of the upriver metapelites, establishing a sink-source relationship. Composition data from two deep groundwater samples near the sediment core show Eh values and As(V)/As(III) ratios of reducing environments and high arsenic, K, Mg, and Fe contents necessary for deriving arsenic from sediments by desorption from clay and dissolution of iron oxyhydroxide. Therefore, groundwater arsenic was mainly derived from groundwater-associated sediments with limited contributions from other sources, such as mud volcanoes.

  8. Hidráulica do escoamento e transporte de sedimentos em sulcos em solo franco-argilo-arenoso Flow hydraulics and sediment transport in rills of a sandy clay loam soil

    Directory of Open Access Journals (Sweden)

    José Ramon Barros Cantalice

    2005-07-01

    capacity to deform the rill and alter flow hydraulics, responsible for rill formation dynamics. The objective of this study was to evaluate flow hydraulic conditions that can provide important information on erosion relationships, soil erodibility and sediment transport in furrows of a recently-tilled Palleudult. Rills were pre-formed in a sandy clay loam soil with an average slope of 0.067 m m-1. Simulated rainfall with an intensity of 74 mm h-1 was applied during 80 min, while rainfall and extra inflows of 0, 10, 20, 30, 40, and 50 L min-1 were jointly applied for the last 20 min of each run in the rill. Results indicated that the rill flow regime varied from transitional subcritical to turbulent subcritical. The rill erosion detachment rates were linear to shear stress. Rill erodibility (Kr was 0.0024 kg-1 s-1 N and critical shear stress (tauc was 2.75 Pa. Two functions to predict sediment transport based on stream power explained 53% of data variability, which indicates the inherent difficulty of predicting solid transport through shallow flows on eroding agricultural lands, and the physical and mineralogical diversity of particles and aggregates of the studied soil.

  9. The Cretaceous sediment-hosted copper deposits of San Marcos (Coahuila, Northeastern Mexico): An approach to ore-forming processes

    Science.gov (United States)

    García-Alonso, Donají; Canet, Carles; González-Partida, Eduardo; Villanueva-Estrada, Ruth Esther; Prol-Ledesma, Rosa María; Alfonso, Pura; Caballero-Martínez, Juan Antonio; Lozano-Santa Cruz, Rufino

    2011-04-01

    In the San Marcos ranges of Cuatrociénegas, NE Mexico, several sediment-hosted copper deposits occur within the boundary between the Coahuila Block, a basement high mostly granitic in composition and Late Paleozoic to Triassic in age, and the Mesozoic Sabinas rift basin. This boundary is outlined by the regional-scale synsedimentary San Marcos Fault. At the basin scale, the copper mineralization occurs at the top of a ˜1000 m thick red-bed succession (San Marcos Formation, Berrisian), a few meters below a conformable, transitional contact with micritic limestones (Cupido Formation, Hauterivian to Aptian). It consists of successive decimeter-thick roughly stratiform copper-rich horizons placed just above the red-beds, in a transitional unit of carbonaceous grey-beds grading to micritic limestones. The host rocks are fine- to medium-grained arkoses, with poorly sorted and subangular to subrounded grains. The detrital grains are cemented by quartz and minor calcite; besides, late iron oxide grain-coating cement occurs at the footwall unmineralized red-beds. The source area of the sediments, indicated by their modal composition, is an uplifted basement. The contents of SiO 2 (40.70-87.50 wt.%), Al 2O 3 (5.91-22.00 wt.%), K 2O (3.68-12.50 wt.%), Na 2O (0.03-2.03 wt.%) and CaO (0.09-3.78 wt.%) are within the ranges expected for arkoses. Major oxide ratios indicate that the sedimentary-tectonic setting was a passive margin. The outcropping copper mineralization essentially consists in a supergene assemblage of chrysocolla, malachite and azurite. All that remains of the primary mineralization are micron-sized chalcocite grains shielded by quartz cement. In addition, pyrite subhedral grains occur scattered throughout the copper-mineralized horizons. In these weathered orebodies copper contents range between 4.24 and 7.72 wt.%, silver between 5 and 92 ppm, and cobalt from 8 to 91 ppm. Microthermometric measurements of fluid inclusions in quartz and calcite crystals from

  10. Tiber delta CO2-CH4 degassing: A possible hybrid, tectonically active Sediment-Hosted Geothermal System near Rome

    Science.gov (United States)

    Ciotoli, G.; Etiope, G.; Marra, F.; Florindo, F.; Giraudi, C.; Ruggiero, L.

    2016-01-01

    Fiumicino town in the Tiber River delta, near Rome International Airport (Italy), is historically affected by large amounts of carbon dioxide (CO2) in the ground and gas eruptions triggered by shallow drilling. While it is known that CO2 originates from carbonate thermometamorphism and/or mantle degassing, the origin of methane (CH4) associated with CO2 is uncertain and the outgassing spatial distribution is unknown. Combining isotope gas geochemistry, soil gas, and structural-stratigraphic analyses, we provide evidence for a hybrid fluid source system, classifiable as Sediment-Hosted Geothermal System (SHGS), where biotic CH4 from sedimentary rocks is carried by deep geothermic CO2 through active segments of a half-graben. Molecular and isotopic composition of CH4 and concentration of heavier alkanes (ethane and propane), obtained from gas vents and soil gas throughout the delta area, reveal that thermogenic CH4 (up to 3.7 vol% in soil gas; δ13CCH4: -37 to -40‰ VPDB-Vienna Peedee Belemnite, and δ2HCH4: -162 to -203‰ VSMOW - Vienna Standard Mean Ocean Water in gas vents) prevails over possible microbial and abiotic components. The hydrocarbons likely result from known Meso-Cenozoic petroleum systems of the Latium Tyrrhenian coast. Overmaturation of source rocks or molecular fractionation induced by gas migration are likely responsible for increased C1/C2+ ratios. CO2 and CH4 soil gas anomalies are scattered along NW-SE and W-E alignments, which, based on borehole, geomorphologic, and structural-stratigraphic analyses, coincide with active faults of a half-graben that seems to have controlled the recent evolution of the Tiber delta. This SHGS can be a source of considerable greenhouse gas emissions to the atmosphere and hazards for humans and buildings.

  11. Tsunami characteristics and formation potential of sandy tsunami deposit in Sanriku Coast: implications from numerical modeling

    Science.gov (United States)

    Sugawara, D.; Haraguchi, T.; Takahashi, T.

    2013-12-01

    Geological investigation of paleotsunami deposit is crucial for knowing the history and magnitude of tsunami events in the past. Among various kinds of grain sizes, sandy tsunami deposit has been best investigated by previous studies, because of its potential for identification in the sedimentary column. Many sandy tsunami deposits have been found from coastal plains, which have sandy beach and low-lying wetlands. However, sandy tsunami deposits in narrow valleys at rocky ria coast have rarely been found. It may be presumed that formation potential of sandy tsunami layer in the rocky coasts is generally lower than coastal plains, because of the absence of sandy beach, tsunami run-up on steeper slope and stronger return flow. In this presentation, characteristics of the 2011 Tohoku-oki earthquake tsunami in Sanriku Coast, a continuous rocky ria coast located in the northeast Japan, is investigated based on numerical modeling. In addition, the formation potential of sandy tsunami deposit is also investigated based on numerical modeling of sediment transport. Preliminary result of tsunami hydrodynamics showed that the waveform and amplification of the tsunami are clearly affected by the local bathymetry, which is associated with submerged topography formed during the last glacial stage. Although the tsunami height in the offshore of each bay is around 8.0 m, the tsunami height at the bay head was increased in different way. The amplification factor at the bay head was typically 2.0 among most of V-shaped narrow embayments; meanwhile the amplification factor is much lower than 1.0 at some cases. The preliminary result of the modeling of sediment transport predicted huge amount of sediments may be suspended into the water column, given that sandy deposit is available there. Massive erosion and deposition of sea bottom sediments may commonly take place in the bays. However, formation of onshore tsunami deposit differs from each other. Whether the suspended sediments

  12. Sandy PMO Disaster Relief Appropriations Act of 2013 Financial Data

    Data.gov (United States)

    Department of Homeland Security — Sandy PMO: Disaster Relief Appropriations Act of 2013 (Sandy Supplemental Bill) Financial Data. This is the Sandy Supplemental Quarterly Financial Datasets that are...

  13. Mineral potential for sediment-hosted copper deposits in the Islamic Republic of Mauritania (phase V, deliverable 75): Chapter K in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

    Science.gov (United States)

    Taylor, Cliff D.; Giles, Stuart A.

    2015-01-01

    The presence of Neoproterozoic through Cambrian, continental, siliciclastic sedimentary rocks interbedded with dolomitic carbonates, shales, and glacial tillites similar to the Katanga Supergroup host rocks of the Central African Copperbelt and other sediment-hosted copper-bearing Proterozoic sequences worldwide, is first order criteria for consideration of the Neoproterozoic units of the Taoudeni Basin in Mauritania as prospective for sediment-hosted copper deposits. Review of the National Mineral Occurrences Database (Marsh and Anderson, 2015) and previous literature suggest that only a handful of small sediment-hosted copper occurrences have been found to date in Mauritania and that the resource potential for this deposit type is low. In the northern Taoudeni Basin, the most important occurrence is at Taradent. This occurrence consists of three mineralized horizons in the lower Neoproterozoic Char Group in three outcrop areas separated by alluvium over a strike length of 12 kilometers (km). The most extensively mineralized horizon consists of malachite and disseminated copper sulfides, and is concentrated at the base of a dolomitic interval, consistent with a reduced faciestype sediment-hosted copper deposit model. Additional and poorly described copper occurrences in the Taoudeni Basin margin sedimentary rocks in northeastern Mauritania, such as Chegga Guettatira and Sidi Bara, may be sediment-hosted copper occurrences and extend the potential throughout this portion of the Basin.

  14. Hurricane Sandy Poster (October 29, 2012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Sandy poster. Multi-spectral image from Suomi-NPP shows Hurricane Sandy approaching the New Jersey Coast on October 29, 2012. Poster size is approximately...

  15. On Sandy Shores. Teacher's Guide.

    Science.gov (United States)

    Strang, Craig; And Others

    The activities in this guide (for grades 2-4) transport students to the sandy shore, one of the most fascinating ecosystems on the planet. At this ecological juncture a multiplicity of life forms find ways to survive, thrive, and interact with each other. Using a wide variety of learning formats, students explore and deepen their understanding of…

  16. Gold and trace element zonation in pyrite using a laser imaging technique: Implications for the timing of gold in orogenic and carlin-style sediment-hosted deposits

    Science.gov (United States)

    Large, R.R.; Danyushevsky, L.; Hollit, C.; Maslennikov, V.; Meffre, S.; Gilbert, S.; Bull, S.; Scott, R.; Emsbo, P.; Thomas, H.; Singh, B.; Foster, J.

    2009-01-01

    Laser ablation ICP-MS imaging of gold and other trace elements in pyrite from four different sediment- hosted gold-arsenic deposits has revealed two distinct episodes of gold enrichment in each deposit: an early synsedimentary stage where invisible gold is concentrated in arsenian diagenetic pyrite along with other trace elements, in particular, As, Ni, Pb, Zn, Ag, Mo, Te, V, and Se; and a later hydrothermal stage where gold forms as either free gold grains in cracks in overgrowth metamorphic and/or hydrothermal pyrite or as narrow gold- arsenic rims on the outermost parts of the overgrowth hydrothermal pyrite. Compared to the diagenetic pyrites, the hydrothermal pyrites are commonly depleted in Ni, V, Zn, Pb, and Ag with cyclic zones of Co, Ni, and As concentration. The outermost hydrothermal pyrite rims are either As-Au rich, as in moderate- to high- grade deposits such as Carlin and Bendigo, or Co-Ni rich and As-Au poor as in moderate- to low-grade deposits such as Sukhoi Log and Spanish Mountain. The early enrichment of gold in arsenic-bearing syngenetic to diagenetic pyrite, within black shale facies of sedimentary basins, is proposed as a critical requirement for the later development of Carlin-style and orogenic gold deposits in sedimentary environments. The best grade sediment-hosted deposits appear to have the gold climax event, toward the final stages of deformation-related hydrothermal pyrite growth and fluid flow. ?? 2009 Society of Economic Geologists, Inc.

  17. Hurricane Sandy washover deposits on Fire Island, New York

    Science.gov (United States)

    La Selle, SeanPaul M.; Lunghino, Brent D.; Jaffe, Bruce E.; Gelfenbaum, Guy; Costa, Pedro J.M.

    2017-02-16

    Washover deposits on Fire Island, New York, from Hurricane Sandy in 2012 were investigated a year after the storm to document the sedimentary characteristics of hurricane washover features. Sediment data collected in the field includes stratigraphic descriptions and photos from trenches, bulk sediment samples, U-channels, and gouge and push cores. Samples and push cores were further analyzed in the laboratory for grain size, density variations using x-ray computed tomography (CT), and surface microtexture using a scanning electron microscope (SEM). Elevation profiles of washover features were measured using Differential Global Positioning System (DGPS) with Real Time Kinematic processing. The DGPS elevations were compared to lidar (light detection and ranging) data from pre- and post-Sandy surveys to assess the degree to which washover deposit thicknesses changed within the year following deposition. Hurricane Sandy washover deposits as much as 1 meter thick were observed in trenches. Initial results show that the upper parts of the deposits have been reworked significantly in some places by wind, but there are still areas where the deposits are almost entirely intact. Where mostly intact, the washover deposits consist of massive or weakly laminated sand near the base, overlain by more strongly laminated sands.

  18. Detection of hydrocarbons in sandy sediments analyzing velocity and amplitude of electromagnetic pulses (GPR-Ground Penetrating Radar); Deteccao de hidrocarbonetos em sedimentos arenosos analisando velocidade e amplitude dos pulsos eletromagneticos (GPR)

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, Tiago C.; Botelho, Marco A.B. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Centro de Pesquisa em Geofisica e Geologia; Machado, Sandro L.; Amparo, Nelson S. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Lab. de Geotecnia Ambiental - GeoAmb

    2004-07-01

    We estimate a hydrocarbon saturation of sandy soils on the basis of the velocity and amplitude of GPR (Ground Penetrating Radar) electromagnetic signals. We acquire CMP (Common Mid Point) data on a tank filled with clean sand. The tank, which has dimensions 1,0 m x 0,7 m x 0,7 m, has filled with water and diesel oil. The velocity decreases from 15 cm/ns for 3% water saturation to 5 cm/ns for 24% water saturation. The presence of hydrocarbon only causes small velocity variations, from 13 cm/ns to 15 cm/ns in the first case. We also investigate the AVO (amplitude variations with offset) of a dry sand/water-saturated sand interface and compare the results to those of the oil-saturated sand/water-saturated sand interface. These results are further compared to the Fresnel equations after the estimation of the reflection coefficient from the reflection hyperbole. The agreement is excellent, and the methodology can be usual to evaluate the type of saturating fluid and the corresponding saturating level. Future experiments will involve the detection and modeling of the critical and Brewster angles to obtain additional information. (author)

  19. The Red Queen race between parasitic chytrids and their host, Planktothrix: a test using a time series reconstructed from sediment DNA.

    Directory of Open Access Journals (Sweden)

    Marcia Kyle

    Full Text Available Parasitic chytrid fungi (phylum Chytridiomycota are known to infect specific phytoplankton, including the filamentous cyanobacterium Planktothrix. Subspecies, or chemotypes of Planktothrix can be identified by the presence of characteristic oligopeptides. Some of these oligopeptides can be associated with important health concerns due to their potential for toxin production. However, the relationship between chytrid parasite and Planktothrix host is not clearly understood and more research is needed. To test the parasite-host relationship over time, we used a sediment core extracted from a Norwegian lake known to contain both multiple Planktothrix chemotype hosts and their parasitic chytrid. Sediment DNA of chytrids and Planktothrix was amplified and a 35-year coexistence was found. It is important to understand how these two antagonistic species can coexistence in a lake. Reconstruction of the time series showed that between 1979-1990 at least 2 strains of Planktothrix were present and parasitic pressure exerted by chytrids was low. After this period one chemotype became dominant and yet showed continued low susceptibility to chytrid parasitism. Either environmental conditions or intrinsic characteristics of Planktothrix could have been responsible for this continued dominance. One possible explanation could be found in the shift of Planktothrix to the metalimnion, an environment that typically consists of low light and decreased temperatures. Planktothrix are capable of growth under these conditions while the chytrid parasites are constrained. Another potential explanation could be due to the differences between cellular oligopeptide variations found between Planktothrix chemotypes. These oligopeptides can function as defense systems against chytrids. Our findings suggest that chytrid driven diversity was not maintained over time, but that the combination of environmental constraints and multiple oligopeptide production to combat chytrids

  20. The Red Queen race between parasitic chytrids and their host, Planktothrix: a test using a time series reconstructed from sediment DNA.

    Science.gov (United States)

    Kyle, Marcia; Haande, Sigrid; Ostermaier, Veronika; Rohrlack, Thomas

    2015-01-01

    Parasitic chytrid fungi (phylum Chytridiomycota) are known to infect specific phytoplankton, including the filamentous cyanobacterium Planktothrix. Subspecies, or chemotypes of Planktothrix can be identified by the presence of characteristic oligopeptides. Some of these oligopeptides can be associated with important health concerns due to their potential for toxin production. However, the relationship between chytrid parasite and Planktothrix host is not clearly understood and more research is needed. To test the parasite-host relationship over time, we used a sediment core extracted from a Norwegian lake known to contain both multiple Planktothrix chemotype hosts and their parasitic chytrid. Sediment DNA of chytrids and Planktothrix was amplified and a 35-year coexistence was found. It is important to understand how these two antagonistic species can coexistence in a lake. Reconstruction of the time series showed that between 1979-1990 at least 2 strains of Planktothrix were present and parasitic pressure exerted by chytrids was low. After this period one chemotype became dominant and yet showed continued low susceptibility to chytrid parasitism. Either environmental conditions or intrinsic characteristics of Planktothrix could have been responsible for this continued dominance. One possible explanation could be found in the shift of Planktothrix to the metalimnion, an environment that typically consists of low light and decreased temperatures. Planktothrix are capable of growth under these conditions while the chytrid parasites are constrained. Another potential explanation could be due to the differences between cellular oligopeptide variations found between Planktothrix chemotypes. These oligopeptides can function as defense systems against chytrids. Our findings suggest that chytrid driven diversity was not maintained over time, but that the combination of environmental constraints and multiple oligopeptide production to combat chytrids could have allowed one

  1. Compilation of Mineral Resource Data for Mississippi Valley-Type and Clastic-Dominated Sediment-Hosted Lead-Zinc Deposits

    Science.gov (United States)

    Taylor, Ryan D.; Leach, David L.; Bradley, Dwight C.; Pisarevsky, Sergei A.

    2009-01-01

    This report contains a global compilation of the mineral resource data for sediment-hosted lead-zinc (SH Pb-Zn) deposits. Sediment-hosted lead-zinc deposits are historically the most significant sources of lead and zinc, and are mined throughout the world. The most important SH Pb-Zn deposits are hosted in clastic-dominated sedimentary rock sequences (CD Pb-Zn) that are traditionally called sedimentary exhalative (SEDEX) deposits, and those in carbonate-dominated sequences that are known as Mississippi Valley-type (MVT) Pb-Zn deposits. In this report, we do not include sandstone-Pb, sandstone-hosted Pb, or Pb-Zn vein districts such as those in Freiberg, Germany, or Coeur d'Alene, Idaho, because these deposits probably represent different deposit types (Leach and others, 2005). We do not include fracture-controlled deposits in which fluorite is dominant and barite typically abundant (for example, Central Kentucky; Hansonburg, N. Mex.) or the stratabound fluorite-rich, but also lead- and zinc-bearing deposits, such as those in southern Illinois, which are considered a genetic variant of carbonate-hosted Pb-Zn deposits (Leach and Sangster, 1993). This report updates the Pb, Zn, copper (Cu), and silver (Ag) grade and tonnage data in Leach and others (2005), which itself was based on efforts in the Canadian Geological Survey World Minerals Geoscience Database Project (contributions of D.F. Sangster to Sinclair and others, 1999). New geological or geochronological data, classifications of the tectonic environment in which the deposits formed, and key references to the geology of the deposits are presented in our report. Data for 121 CD deposits, 113 MVT deposits, and 6 unclassified deposits that were previously classified as either SEDEX or MVT in the Leach and others (2005) compilation, are given in appendix table A1. In some cases, mineral resource data were available only for total district resources, but not for individual mines within the district. For these

  2. Microbial Community in a Sediment-Hosted CO2 Lake of the Southern Okinawa Trough Hydrothermal Field

    Science.gov (United States)

    Inagaki, F.; Kuypers, M. M.; Tsunogai, U.; Ishibashi, J.; Nakamura, K.; Treude, T.; Ohkubo, S.; Nakaseama, M.; Gena, K.; Chiba, H.; Hirayama, H.; Nunoura, T.; Takai, K.; Jorgensen, B. B.; Horikoshi, K.; Boetius, A.

    2006-12-01

    One-carbon assimilating (micro-)organisms play an important role for global carbon cycling; however, the increasing level of anthropogenic CO2 in the atmosphere has exceeded the capacity of natural biological feedback, hence as greenhouse gasses it is expected to cause climacteric change with negative effects on the earth's ecosystems and human society. To reduce CO2 emissions into the atmosphere, a variety of options have been discussed, including a disposal of CO2 into the deep ocean. However, the impact of CO2 disposal on deep-sea ecosystems as well as of the consequent microbiological feedback remains largely unknown. At the Yonaguni Knoll IV hydrothermal field, southern Okinawa Trough, we observed a natural liquid CO2 lake in sediments overlying elemental sulfur and CO2 hydrates at a water depth of 1380m. The liquid CO2 droplets were composed of 85% CO2 and 14% methane with hydrogen below the detection limit. We found high abundances (>109 cm-3) of microbial cells in sediment pavements above the CO2 lake, decreasing to strikingly low cell numbers (10&^{7} cm-3) at the liquid CO2/CO2-hydrate interface. Molecular ecological study based on the sequences of 16S rRNA genes showed that the key groups in these sediments were: (i) the anaerobic methanotrophic archaea ANME-2c and the Eel-2 group of Deltaproteobacteria, and (ii) sulfur-metabolizing chemolithotrophs within the Gamma- and Epsilonproteobacteria. The detection of functional genes (mcrA, cbbL) related to one- carbon assimilation as well as the presence of highly 13C-depleted archaeal and bacterial lipid biomarkers suggest that microorganisms assimilating CO2 and/or methane dominate the liquid CO2 and CO2-hydrate-bearing sediments. We propose that the Yonaguni Knoll is an exceptional natural laboratory for the study of consequences of CO2 disposal as well as of natural CO2 reservoirs as potential microbial habitats on early Earth and other celestial bodies.

  3. Qualitative assessment of selected areas of the world for undiscovered sediment-hosted stratabound copper deposits: Chapter Y in Global mineral resource assessment

    Science.gov (United States)

    Zientek, Michael L.; Wintzer, Niki E.; Hayes, Timothy S.; Parks, Heather L.; Briggs, Deborah A.; Causey, J. Douglas; Hatch, Shyla A.; Jenkins, M. Christopher; Williams, David J.; Zientek, Michael L.; Hammarstrom, Jane M.; Johnson, Kathleen M.

    2015-12-14

    A qualitative mineral resource assessment of sediment-hosted stratabound copper mineralized areas for undiscovered copper deposits was performed for 10 selected areas of the world. The areas, in alphabetical order, are (1) Belt-Purcell Basin, United States and Canada; (2) Benguela and Cuanza Basins, Angola; (3) Chuxiong Basin, China; (4) Dongchuan Group rocks, China; (5) Egypt–Israel–Jordan Rift, Egypt, Israel, and Jordan; (6) Maritimes Basin, Canada; (7) Neuquén Basin, Argentina; (8) Northwest Botswana Rift, Botswana and Namibia; (9) Redstone Copperbelt, Canada; and (10) Salta Rift System, Argentina. This assessment (1) outlines the main characteristics of the areas, (2) classifies known deposits by deposit model subtypes, and (3) ranks the areas according to their potential to contain undiscovered copper deposits.

  4. 青岛灵山湾潮间带沉积物粒度参数高光谱定量反演%Quantitative inversion of sandy intertidal sediment grain size parameters content with hyperspectral in Lingshan Bay of Qingdao

    Institute of Scientific and Technical Information of China (English)

    陈晓琳; 孙根云; 徐方建; 赵永芳; 王振杰

    2015-01-01

    The sediment grain-size parameters of intertidal zone is not only a reference object for the research of modern coastal dynamics but also a basis for the evaluation of the sustainable development of human activities. This paper takes the surface sediment and the hyperspectral information of the intertidal zone in Lingshan Bay as study objects to analyze the ability in grain size parameters identifying. Mathematical transformations were taken aiming at solving the extraction difficulties in hyperspectral data. Multi-layer perceptron ANN (Artificial Neural Network) was established to build a relation model between the parameters and spectral reflectance to explore the feasibility of quantitative inversion of sediment characteristics. The final results show that using hyperspectral data to determine sediment grain-size parameters of intertidal zone is feasible. The advantages, i.e. fast and accurate, provide a new method for determining the intertidal zone sediment parameters. This would provide a reference for accurately monitoring and researching on the changes of intertidal zone.%潮间带表层沉积物粒度参数不仅是研究现代海岸动态和变迁的参照,也是评价人类活动可持续发展的依据。本文以灵山湾潮间带野外实地采集潮滩表层沉积物及其表面实时光谱信息为研究对象,分析高光谱用于粒度参数识别的能力。针对高光谱信息提取的困难,对光谱数据进行数学变换,利用多层感知器神经网络建立沉积物粒度参数与光谱反射率之间的关系模型,探索了利用表层沉积物反射光谱特性进行沉积物特征定量反演的可行性。结果表明:基于高光谱对沉积物粒度参数的定量预测是可行的,建立的预测模型可以较准确地反映潮间带沉积物粒度特征,其快速、准确的优点为测定潮间带表层沉积物粒度参数提供了一种新方法。该模型的建立为进一步提高潮间带变化监测和

  5. Denitrification coupled to pyrite oxidation and changes in groundwater quality in a shallow sandy aquifer

    NARCIS (Netherlands)

    Zhang, Y.-C.; Slomp, C.P.; Broers, H.P.; Passier, H.F.; Cappellen, P. van

    2009-01-01

    This study focuses on denitrification in a sandy aquifer using geochemical analyses of both sediment and groundwater, combined with groundwater age dating (3H/3He). The study sites are located underneath cultivated fields and an adjacent forested area at Oostrum, The Netherland

  6. High-density turbidity currents: Are they sandy debris flows?

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

    1996-01-01

    Conventionally, turbidity currents are considered as fluidal flows in which sediment is supported by fluid turbulence, whereas debris flows are plastic flows in which sediment is supported by matrix strength, dispersive pressure, and buoyant lift. The concept of high-density turbidity current refers to high-concentration, commonly non-turbulent, flows of fluids in which sediment is supported mainly by matrix strength, dispersive pressure, and buoyant lift. The conventional wisdom that traction carpets with entrained turbulent clouds on top represent high-density turbidity currents is a misnomer because traction carpets are neither fluidal nor turbulent. Debris flows may also have entrained turbulent clouds on top. The traction carpet/debris flow and the overriding turbulent clouds are two separate entities in terms of flow rheology and sediment-support mechanism. In experimental and theoretical studies, which has linked massive sands and floating clasts to high-density turbidity currents, the term high-density turbidity current has actually been used for laminar flows. In alleviating this conceptual problem, sandy debris flow is suggested as a substitute for high-density turbidity current. Sandy debris flows represent a continuous spectrum of processes between cohesive and cohesionless debris flows. Commonly they are rheologically plastic. They may occur with or without entrained turbulent clouds on top. Their sediment-support mechanisms include matrix strength, dispersive pressure, and buoyant lift. They are characterized by laminar flow conditions, a moderate to high grain concentration, and a low to moderate mud content. Although flows evolve and transform during the course of transport in density-stratified flows, the preserved features in a deposit are useful to decipher only the final stages of deposition. At present, there are no established criteria to decipher transport mechanism from the depositional record.

  7. Sediment Management Options for Galveston Island, Texas

    Science.gov (United States)

    2015-06-15

    considered the “Face of Galveston.” Sediment Budget Morang (2006) calculated a sediment budget for the north Texas shore between Sabine Pass and San Luis...cross- shore beach profiles. The sediment budget was completed by hand and then the results were added to the Sediment Budget Analysis System (SBAS...University (Dellapenna, personal communications 2003) conducted seismic studies detecting sandy facies offshore of the south jetty making an

  8. Survival and persistence of host-associated Bacteroidales cells and DNA in comparison with Escherichia coli and Enterococcus in freshwater sediments as quantified by PMA-qPCR and qPCR.

    Science.gov (United States)

    Kim, Minji; Wuertz, Stefan

    2015-12-15

    Decay of the fecal source identifier Bacteroidales in sediments has not been studied until now. Two types of microcosms inoculated with human, cow and dog feces were constructed to investigate the survival and persistence of host-associated Bacteroidales cells and their DNA, respectively, in freshwater sediments: (i) a completely anaerobic microcosm where feces were entirely mixed with sediments for estimating decay of Bacteroidales in oxygen-free sediments at two temperatures (6 °C and 20 °C) and (ii) a core microcosm where feces in the overlying water column settled on top of undisturbed core sediments. Quantitative PCR (qPCR) along with propidium monoazide (PMA) was used to differentiate between genetic markers present in intact cells and total intracellular as well as extracellular marker DNA. Regulated fecal indicator bacteria were measured by cultivation (Escherichia coli and Enterococcus) and qPCR (Enterococcus) in relation to Bacteroidales-associated host markers. In anaerobic microcosms, the survival and persistence of Bacteroidales cells and DNA in sediments were considerably extended, especially at the lower temperature of 6 °C, with two-log reduction times (T99) >56 d (cells) and >169 d (DNA). Bacteroidales DNA persisted up to five times longer than cells in anaerobic microcosms at 6 °C, whereas decay rates of cells and DNA were not significantly different at 20 °C in anaerobic microcosms. In core microcosms, the levels of Bacteroidales cells and DNA decreased approximately six times more slowly in sediments than in overlying water; T99 values of Bacteroidales cells and DNA were 6-9 d (water) and 29-82 d (sediment). The survival of universal, human-, ruminant- and dog-associated Bacteroidales cells in sediments was similar in both microcosms under each given condition, as was the persistence of DNA. Decay rate constants of Bacteroidales cells and DNA were comparable with those of cultivable Enterococcus and E. coli cells in core sediments while

  9. 沉积岩型层状铜矿床研究进展%Research Progresses on Sediment-hosted Stratiform Copper Deposit

    Institute of Scientific and Technical Information of China (English)

    刘玄; 范宏瑞; 胡芳芳; 杨奎锋; 邱正杰

    2015-01-01

    沉积岩型层状铜矿床是全球第二重要的铜矿类型,重要性仅次于斑岩型铜矿床。并且,它们常伴生一定规模的钴、银、铅、锌、铀、金、铂族元素等其他金属资源。其矿体通常呈层状、似层状发育在沉积盆地的还原性岩石或地层中。大多数沉积岩型层状铜矿床形成于围岩的成岩作用或者成岩晚阶段,但也经常会受到成矿后变质作用、变形作用的改造,发生成矿物质的活化—再沉淀。原生成矿作用的发生通常要经历成矿流体(低温、中—高盐度、含硫)在矿体下盘的红层中持续、长期的循环,萃取铜等金属元素,随后沿着盆地边界断裂迁移至盆地还原性地层中或者被迁移的还原性物质(石油、天然气)还原而发生铜等成矿物质的沉淀。超大规模的层状铜矿化可能对应地球地质历史时期特殊的地质事件和地质条件,其中包括超大陆裂解、炎热干旱的古气候、大氧化事件以及冰期和富镁的海洋等。%Sediment-hosted Stratiform Copper Deposits (SSC ) are one of the most important copper suppliers around the world and are also significant sources for Co,Ag,Pb,Zn,U,Ag and PGE.They normally occur as sulfide disseminates in restricted layers within a sedimentary sequence but do not necessarily follow sedimentary bedding.Most SSCs are formed during or at the late stage of host rock lithification (diagenesis ) by low temperature,intermediate to high salinity and sulfur-rich basinal fluids which circulated in the footwall red bed sequences so as to acquire ore-forming elements such as Cu and S.Metal (copper)precipitation is primarily induced by chemical reduction of the upward-migrating basinal fluids by in-situ reductant in the hanging wall sediments or mobile hydrocarbon within the red beds.Some of them may have been altered and remobilized during regional deformation or metamorphism later on.Supergiant sediment-hosted copper

  10. Sediment distribution in the offshore regions of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Veerayya, M.; Murty, C.S.; Varadachari, V.V.R.

    grades just adjacent to the beaches followed by either silty sands or sandy silts. Further seaward, the nearshore area off Calangute shows sandy mud in the south and mud in the north while clay occurs in the Colva area. Relatively coarse grained sediments...

  11. IMPLEMENTASI SANDI HILL UNTUK PENYANDIAN CITRA

    Directory of Open Access Journals (Sweden)

    JJ Siang

    2002-01-01

    Full Text Available Hill's code is one of text encoding technique. In this research, Hill's code is extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used as a key. The results show that Hill's code is suitable for image whose RGB values vary highly. On the contrary, it is not suitable for less varied RGB images since its original pattern is still persisted in encrypted image. Hill's code for image encoding has also disadvantage in the case that the key matrix is not unique. However, for daily application, with good key matrix, Hill's code can be applied to encode image since it's process only deals with simple matrix operation so it become fast. Abstract in Bahasa Indonesia : Sandi Hill merupakan salah satu teknik penyandian teks. Dalam penelitian ini, pemakaian sandi Hill diperluas dari teks ke citra bertipe BMP 24 bit. Matriks yang dipakai berordo 2x2 dan 3x3. Hasil percobaan menunjukkan bahwa sandi Hill cocok untuk enkripsi citra dengan variasi nilai RGB antar piksel berdekatan yang tinggi (seperti foto, tapi tidak cocok untuk citra dengan variasi nilai RGB yang rendah (seperti gambar kartun karena pola citra asli masih tampak dalam citra sandi. Sandi Hill juga memiliki kelemahan dalam hal tidak tunggalnya matriks kunci yang dapat dipakai. Akan tetapi untuk pemakaian biasa, dengan pemilihan matriks kunci yang baik, sandi Hill dapat dipakai untuk penyandian karena hanya melibatkan operasi matriks biasa sehingga prosesnya relatif cepat. Kata kunci: Sandi Hill, Citra, Relatif Prima.

  12. Uncertainties in sandy shorelines evolution under the Bruun rule assumption

    Directory of Open Access Journals (Sweden)

    Gonéri eLe Cozannet

    2016-04-01

    Full Text Available In the current practice of sandy shoreline change assessments, the local sedimentary budget is evaluated using the sediment balance equation, that is, by summing the contributions of longshore and cross-shore processes. The contribution of future sea-level-rise induced by climate change is usually obtained using the Bruun rule, which assumes that the shoreline retreat is equal to the change of sea-level divided by the slope of the upper shoreface. However, it remains unsure that this approach is appropriate to account for the impacts of future sea-level rise. This is due to the lack of relevant observations to validate the Bruun rule under the expected sea-level rise rates. To address this issue, this article estimates the coastal settings and period of time under which the use of the Bruun rule could be (invalidated, in the case of wave-exposed gently-sloping sandy beaches. Using the sedimentary budgets of Stive (2004 and probabilistic sea-level rise scenarios based on IPCC, we provide shoreline change projections that account for all uncertain hydrosedimentary processes affecting idealized coasts (impacts of sea-level rise, storms and other cross-shore and longshore processes. We evaluate the relative importance of each source of uncertainties in the sediment balance equation using a global sensitivity analysis. For scenario RCP 6.0 and 8.5 and in the absence of coastal defences, the model predicts a perceivable shift toward generalized beach erosion by the middle of the 21st century. In contrast, the model predictions are unlikely to differ from the current situation in case of scenario RCP 2.6. Finally, the contribution of sea-level rise and climate change scenarios to sandy shoreline change projections uncertainties increases with time during the 21st century. Our results have three primary implications for coastal settings similar to those provided described in Stive (2004 : first, the validation of the Bruun rule will not necessarily be

  13. EAARL Coastal Topography-Sandy Hook 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface/bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Gateway National Recreation Area's Sandy Hook Unit in New Jersey...

  14. Heterotrophic bacterial populations in tropical sandy beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; LokaBharathi, P.A.

    Distribution pattern of heterotrophic bacterial flora of three sandy beaches of the west coast of India was studied. The population in these beaches was microbiologically different. Population peaks of halotolerant and limnotolerant forms were...

  15. Descriptive models, grade-tonnage relations, and databases for the assessment of sediment-hosted copper deposits: with emphasis on deposits in the Central Africa Copperbelt, Democratic Republic of the Congo and Zambia: Chapter J in Global mineral resource assessment

    Science.gov (United States)

    Taylor, Cliff D.; Causey, J. Douglas; Denning, Paul D.; Hammarstrom, Jane M.; Hayes, Timothy S.; Horton, John D.; Kirschbaum, Michael J.; Parks, Heather L.; Wilson, Anna B.; Wintzer, Niki E.; Zientek, Michael L.

    2013-01-01

    The Central African Copperbelt (CACB) is one of the most important copper-producing regions of the world. The majority of copper produced in Africa comes from this region defined by the Neoproterozoic Katanga sedimentary basin of the southern Democratic Republic of the Congo (DRC) and northern Zambia. Copper in the CACB is mined from sediment-hosted stratabound copper deposits associated with red beds and includes the giant deposits in the Kolwezi and Tenge-Fungurume districts in the DRC and the Konkola-Musoshi and Nchanga-Chingola districts in Zambia. In recent years, sediment-hosted structurally controlled replacement and vein (SCRV) copper deposits, such as the giant Kansanshi deposit in Zambia have become important exploration targets in the CACB region.

  16. Simulation and control of morphological changes due to dam removal in the Sandy River, Oregon, USA

    Science.gov (United States)

    Ding, Y.; Altinakar, M. S.

    2015-03-01

    A one-dimensional channel evolution simulation model (CCHE1D) is applied to assess morphological changes in a reach of the Sandy River, Oregon, USA, due to the Marmot Dam removal in 2007. Sediment transport model parameters (e.g. sediment transport capacity, bed roughness coefficient) were calibrated using observed bed changes after the dam removal. The validated model is then applied to assess long-term morphological changes in response to a 10-year hydrograph selected from historical storm water records. The long-term assessment of sedimentation gives a reasonable prediction of morphological changes, expanding erosion in reservoir and growing deposition immediately downstream of the dam site. This prediction result can be used for managing and planning river sedimentation after dam removal. A simulation-based optimization model is also applied to determine the optimal sediment release rates during dam-removal that will minimize the morphological changes in the downstream reaches.

  17. Trophic niche shifts driven by phytoplankton in sandy beach ecosystems

    Science.gov (United States)

    Bergamino, Leandro; Martínez, Ana; Han, Eunah; Lercari, Diego; Defeo, Omar

    2016-10-01

    Stable isotopes (δ13C and δ15N) together with chlorophyll a and densities of surf diatoms were used to analyze changes in trophic niches of species in two sandy beaches of Uruguay with contrasting morphodynamics (i.e. dissipative vs. reflective). Consumers and food sources were collected over four seasons, including sediment organic matter (SOM), suspended particulate organic matter (POM) and the surf zone diatom Asterionellopsis guyunusae. Circular statistics and a Bayesian isotope mixing model were used to quantify food web differences between beaches. Consumers changed their trophic niche between beaches in the same direction of the food web space towards higher reliance on surf diatoms in the dissipative beach. Mixing models indicated that A. guyunusae was the primary nutrition source for suspension feeders in the dissipative beach, explaining their change in dietary niche compared to the reflective beach where the proportional contribution of surf diatoms was low. The high C/N ratios in A. guyunusae indicated its high nutritional value and N content, and may help to explain the high assimilation by suspension feeders at the dissipative beach. Furthermore, density of A. guyunusae was higher in the dissipative than in the reflective beach, and cell density was positively correlated with chlorophyll a only in the dissipative beach. Therefore, surf diatoms are important drivers in the dynamics of sandy beach food webs, determining the trophic niche space and productivity. Our study provides valuable insights on shifting foraging behavior by beach fauna in response to changes in resource availability.

  18. Sediment Budget Analysis; Masonboro Inlet, North Carolina

    Science.gov (United States)

    2017-08-15

    littoral sediments or sediments derived principally from the beaches, consisting of generally sandy material. Other sediments consisting of fine-grain...propagate only from the seaward boundary toward shore . It includes features such as wave generation, wave reflection, and bottom frictional dissipation...analysis. The regional shore line adopted in the study is oriented at 36.17o clockwise from north, as shown in Figure 8. Statistics were performed for

  19. Luminescence dating of Holocene lacustrine sediments from the southeastern Mu Us sandy land:Comparison of quartz OSL and K-feldspar pIRIR150 ages%毛乌素沙地东南缘全新世湖相地层石英和钾长石释光测年对比∗

    Institute of Scientific and Technical Information of China (English)

    冯玉静; 隆浩; 黄银洲; 王洪娇; 王乃昂; 高磊; 沈吉

    2015-01-01

    samples were well bleached before deposition, and the resultant ages of quartz fraction are reliable. For K-feldspar fraction, a new post-IR IRSL protocol measured at 150℃ ( pIRIR150 ) was used to determine the De. Dose recovery tests and lumi-nescence characteristics of K-feldspar meet the requirement well. A set of tests, such as residual test and fading test, was carried out. Residual doses of pIRIR150 signal are between-0. 2 and 0. 026 Gy, which can be considered negligible for the Holocene sedi-ments. The g-values of pIRIR150 signal (0. 55 1. 71(% /decade)) are much lower, comparing with that of IRSL50 signal, or even negligible. Thus, we propose that the use of pIRIR150 signal is able to reduce anomalous fading to a negligible level. Subse-quently, the K-feldspar pIRIR150 ages are not corrected for anomalous fading. For the three samples, the quartz ages are 11. 3 ± 0. 9, 6. 5 ± 0. 6 and 2. 7 ± 0. 2 ka BP, respectively, and the K-feldspar ages are 10. 0 ± 0. 7, 6. 9 ± 0. 5 and 2. 4 ± 0. 2 ka BP, re-spectively. Both ages from the two methods agree with each other within the error ranges. Therefore, K-feldspar pIRIR150 protocol can be applied for dating the Holocene lacustrine sediments from southeast Mu Us sandy land. Our research found a method to date the samples that their luminescence signal intensity of quartz is too low to be detected, and a geochronology to support for environ-mental changes in the Holocene, especially in the historical period ( past 2000 years) .

  20. Hurricane Sandy washover deposits on southern Long Beach Island, New Jersey

    Science.gov (United States)

    Bishop, James M.; Richmond, Bruce M.; Zaremba, Nicholas J.; Lunghino, Brent D.; Kane, Haunani H.

    2016-07-22

    Sedimentologic and topographic data from Hurricane Sandy washover deposits were collected from southern Long Beach Island, New Jersey, in order to document changes to the barrier-island beaches, dunes, and coastal wetlands caused by Hurricane Sandy and subsequent storm events. These data will provide a baseline dataset for use in future coastal change descriptive and predictive studies and assessments. The data presented here were collected as part of the U.S. Geological Survey’s Barrier Island and Estuarine Wetland Physical Change Assessment Project (http://coastal.er.usgs.gov/sandy-wetland-assessment/), which aims to assess ecological and societal vulnerability that results from long- and short-term physical changes to barrier islands and coastal wetlands. This report describes data that were collected in April 2015, approximately 2½ years after Hurricane Sandy’s landfall on October 29, 2012. During the field campaign, washover deposits were photographed and described, and sediment cores, sediment samples, and surface-elevation data were collected. Data collected during this study, including sample locations and elevations, core photographs, computed tomography scans, descriptive core logs, sediment grain-size data, and accompanying Federal Geographic Data Committee metadata, are available in the associated U.S. Geological Survey data release (Bishop and others, 2016; http://dx.doi.org/10.5066/F7PK0D7S).

  1. Revealing accumulation zones of plastic pellets in sandy beaches.

    Science.gov (United States)

    Moreira, Fabiana T; Balthazar-Silva, Danilo; Barbosa, Lucas; Turra, Alexander

    2016-11-01

    Microplastics such as pellets are reported worldwide on sandy beaches, and have possible direct and indirect impacts on the biota and physical characteristics of the habitats where they accumulate. Evaluations of their standing stock at different spatial scales generate data on levels of contamination. This information is needed to identify accumulation zones and the specific beach habitats and communities that are likely to be most affected. Standing stocks of plastic pellets were evaluated in 13 sandy beaches in São Paulo state, Brazil. The sampling strategy incorporated across-shore transects from coastal dunes and backshores, and vertical profiles of the accumulated pellets down to 1 m depth below the sediment surface. Accumulation zones were identified at regional (among beaches) and local (between compartments) scales. At the regional scale pellet density tended to increase at beaches on the central and southwestern coast, near ports and factories that produce and transport the largest amounts of pellets in the country. At the local scale coastal dunes showed larger accumulations of pellets than backshores. For both compartments pellets tended to occur deeper in areas where standing stocks were larger. Most of the pellets were concentrated from the surface down to 0.4 m depth, suggesting that organisms inhabiting this part of the sediment column are more exposed to the risks associated with the presence of pellets. Our findings shed light on the local and regional scales of spatial variability of microplastics and their consequences for assessment and monitoring schemes in coastal compartments. Copyright © 2016. Published by Elsevier Ltd.

  2. Broadband Scattering from Sand and Sand/Mud Sediments with Extensive Environmental Characterization

    Science.gov (United States)

    2017-01-30

    frequency sound speed and attenuation measurements in sandy sediments with a portable velocimeter.” (4) Proceedings from the 2nd International...Bay, FL off the shore of Shell Island. The sediment consisted of the 15 cm mud layer overlying a muddy, coarse sand basement. Scattering data was...Demoulin, X., L. Guillon, and B.T. Hefner (2017), “High-frequency sound speed and attenuation measurements in sandy sediments with a portable

  3. Penetration grouting reinforcement of sandy gravel

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; PENG Zhen-bin; TANG Yi-qun; PENG Wen-xiang; HE Zhong-ming

    2008-01-01

    To study the relationship between grouting effect and grouting factors, three factors (seven parameters) directionless pressure and small cycle grouting model experiment on sandy gravel was done, which was designed according to uniform design method. And regressing was applied to analysis of the test data. The two models test results indicate that when the diffusing radius of grout changes from 26 to 51 era, the grouted sandy gravel compressing strength changes fTom 2.13 to 12.30 MPa; the relationship between diffusing radius(R) and water cement ratio(m), permeability coefficient(k), grouting pressure(p), grouting time(t) is R=19.953m0.121k0.429p0.412t0.437, the relationship between compressing strength(P) and porosity(n), water cement ratio, grouting pressure, grouting time is P=0.984n0.517m-1.488p0.118t0.031.So the porosity of sandy gravel, the permeability coefficient of sandy gravel, grouting pressure, grouting time, water cement ratio are main factors to influence the grouting effect. The grouting pressure is the main factor to influence grouting diffusing radius, and the water cement ratio is the main factor to influence grouted sandy gravel compressing strength.

  4. [Simulation alfalfa growth in Wulanbuhe sandy region].

    Science.gov (United States)

    Bai, Wenming; Bao, Xuemei

    2002-12-01

    Based on the theories of accumulated temperature and on the physio-ecological characteristics of Medicago sativa, a simulation model for its growth under soil water stress in arid sandy region was developed. The model was mainly composed of four modules: the stage module of growth, the dynamic module of leaf area index, the accumulated module of dry matter, and the distributive module of dry matter. After simulating and calculating, the model could be used to predict the growing progress and dynamic changes of leaf area and yield for herbage in sandy region. The result shows that the application of the model to production is usually effective.

  5. 77 FR 74341 - Establishing the Hurricane Sandy Rebuilding Task Force

    Science.gov (United States)

    2012-12-14

    ... the Hurricane Sandy Rebuilding Task Force By the authority vested in me as President by the.... Hurricane Sandy made landfall on October 29, 2012, resulting in major flooding, extensive structural damage... assist the affected region. A disaster of Hurricane Sandy's magnitude merits a comprehensive...

  6. Sedimentation in a river dominated estuary

    CSIR Research Space (South Africa)

    Cooper, JAG

    1993-10-01

    Full Text Available The Mgeni Estuary on the wave dominated cast coast of South Africa occupies a narrow, bedrock confined, alluvial valley and is partially blocked at the coast by an elongate sandy barrier. Fluvial sediment extends to the barrier and marine depositon...

  7. Outdoor rearing facilities of free spawning calanoid copepods for turbot larva can host a bank of resting eggs in the sediment

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Blanda, Elisa; Drillet, Guillaume;

    2016-01-01

    match the larval needs. When turbot larvae reach metamorphosis and are transferred indoor for weaning, the outdoor tank sediments may reveal vast amounts of copepod eggs undergoing dormancy. Here, we report a copepod species succession firstly among Centropages hamatus and then Acartia spp. both...

  8. Lithology, mineralogy and geochemical characterizations of sediment-hosted Sr-F deposits in the eastern Neo-Tethyan region - With special reference to evaporation and halokinesis in Tunisia

    Science.gov (United States)

    Dill, H. G.; Nolte, N.; Hansen, B. T.

    2014-04-01

    The Neo-Tethyan basin is known for its sediment-hosted Sr deposits in Spain, Turkey, Cyprus, and the Gulf Region. Sediment-hosted Sr-F deposits with base metals formed in the rim sinks and on top of salt domes resulting from halokinesis of Triassic evaporites near the southern edge of the Mediterranean Sea in Tunisia. These evaporites delivered part of the elements, created a basin-and-swell topography and provided the local and regional unconformities to which many of the mineral deposits are related. Five mineralizing processes, each with characteristic sedimentary ore textures, are related to this subsurface salt movement: (1 + 2) Early- and late-stage replacement ("zebra rocks"), (3) hydraulic fracturing ("fitting breccia" sensuDill and Weber, 2010b), (4) remobilization ("spinifex structures"), and (5) open-space filling ("caves and vein-like deposits"). Basinal brines from Mesozoic aquifers delivered Pb, Zn, Cd, REE, Y, Hg, and Se, while Sr, Cs, Be, Li, Cu and Co have been derived from Cenozoic salinas of the Neo-Tethyan basin. Mixing of Mesozoic and Cenozoic brines between 28 and 19 Ma provoked the emplacement of Sr-F mineralization at temperatures below 200 °C under strong alkaline conditions. Epigenetic polyphase Sr-F deposits bearing base-metals which are closely related to salt domes (Tunisian-Type) may be traced into epigenetic monophase Sr deposits within bioherms (Cyprus-Type) devoid of Pb, Zn and F. Moving eastward, syndiagenetic monophase Sr deposits in biostromes (Gulf-Type) herald the beginning of Sr concentration in Miocene sabkhas of the Neo-Tethys. The current results are based upon field-related sediment petrography and on mineralogical studies, which were supplemented by chemical studies. The present studies bridge the gap between epigenetic carbonate-hosted MVT and syndiagenetic evaporite deposits, both of which developed during the same time span (Neogene) and were hosted by the same environment (near-shore marine marginal facies of the Neo

  9. Composition, structure and properties of sediment thermal springs of Kamchatka

    Science.gov (United States)

    Shanina, Violetta; Smolyakov, Pavel; Parfenov, Oleg

    2016-04-01

    The paper deals with the physical and mechanical properties sediment thermal fields Mutnovsky, Lower Koshelevo and Bannyh (Kamchatka). This multi-component soils, mineral and chemical composition of which depends on the formation factors (pH, temperature, salinity of water, composition and structure of the host volcanic rocks). Samples Lower Koshelevo sediment thermal sources differ in the following composition: smectite, kaolinite, kaolinite-smectite mixed-mineral. Samples of sediment thermal springs Mutnovsky volcano in accordance with the X-ray analysis has the following composition: volcanic glass, crystalline sulfur, plagioclase, smectite, illite-smectite mixed, illite, chlorite, quartz, cristobalite, pyrite, melanterite, kaolinite. Natural moisture content samples of sediment thermal springs from 45 to 121%, hygroscopic moisture content of 1.3 to 3.7%. A large amount of native sulfur (up to 92%) and the presence of amorphous material gives low values of density of solid particles (up to 2.1 g/cm3) samples Mutnovskii thermal field. The values of the density of solids sediment Koshelevo and Bannyh hot springs close to those of the main components of mineral densities (up to 2.6-3.0 g/cm3). The results of the particle size distribution and microaggregate analysis of sediment thermal springs Lower Koshelevo field shows that the predominance observed of particles with a diameter from 0.05 mm to 0.25 mm, the coefficient of soil heterogeneity heterogeneous. In the bottom sediments of the thermal springs of the volcano Mutnovsky poorly traced predominance of one faction. Most prevalent fraction with particle size 0.01 - 0.05 mm. When analyzing the content in the soil microaggregates their content is shifted towards particles with a diameter of 0.25 mm. The contents of a large number of large (1-10 mm), porous rock fragments, due to the deposition of pyroclastic material from the eruptions of the last century. Present in large amounts rounded crystals of native sulfur

  10. Degradation of the Pesticides Mecoprop and Atrazine in Unpolluted Sandy Aquifers

    DEFF Research Database (Denmark)

    Klint, Mikala; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    The potential for biodegradation of the pesticides mecoprop ((+/-)-2-(4-chloro-2-methyl-phenoxy)propionic acid) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in an aerobic aquifer was investigated in laboratory batch experiments. The experiments were performed with groundwater...... and suspensions of groundwater and aquifer sediment collected from a pristine sandy aquifer. Following a lag period of 35 to 40 d, mecoprop in a concentration of 100 mu-g/L was degraded in 30 d in groundwater at 10 degree C. New additions of 100 to 140 mu-g mecoprop/L were degraded within a week. In suspensions...... of groundwater and aquifer sediment, mecoprop in the concentration range 75 to 300 mu-g/L was degraded in 15 d, following a lag period of less than 7 d. Experiments performed with sediments taken from different depths indicate that there was a considerable variation in the degradation potential within...

  11. An assessment of Hyalella azteca burrowing activity under laboratory sediment toxicity testing conditions.

    Science.gov (United States)

    Doig, Lorne E; Liber, Karsten

    2010-09-01

    Burrowing of the freshwater amphipod Hyalella azteca was evaluated under laboratory conditions similar to those recommended for standard sediment toxicity testing in Canada (EPS 1/RM/33; Environment Canada, 1997) and the United States (EPA/600/R-99/064; US EPA, 2000). Sediment type, time of day (light versus dark), size of animal, and the presence or absence of food were varied to assess their effects on burrowing activity. Hyalella azteca were found to burrow rapidly in fine, organic-rich sediments, but were slower to burrow in a sandy sediment. There was no increase in the number of animals occupying the sediment surface of a fine, organic-rich sediment after 4h of darkness compared to the previous 4h of light. Over a 9- to 10-d duration, a higher percentage of animals occupied the surface of the sandy sediment. The addition of food promoted burrowing in sandy sediment, as did using smaller animals. Overall, longer-duration tests involving older animals and coarse sediments may require formal observation to confirm burrowing and ensure adequate sediment exposure. The addition of food during a test may promote the burrowing of larger animals in coarse sediments, but may not be necessary in field-collected sediments that are not excessively sandy.

  12. Estimation of potentially contaminated sediment volume in cases of oil spill in a summer conditions to sandy beaches of Rio Grande do Sul, Brazil; Estimativa do volume sedimentar potencialmente contaminado em casos de derrame de oleo em condicoes de verao para praias arenosas do Rio Grande do Sul

    Energy Technology Data Exchange (ETDEWEB)

    Costi, Juliana; Calliari, Lauro J. [Fundacao Universidade Federal do Rio Grande (FURG), RS (Brazil)

    2008-07-01

    Field experiments relating oil of two different densities with sediment penetration along ocean beaches with distinct morphodynamic behavior along the RS coastline indicates that, for both types of oil, higher penetration is associated to beaches which display higher mean grain size. Based on penetration depth it is possible to estimate the volume of contaminated sediments due to oil spills that eventually can reach the coast. Sediment cores sampled at 80 days interval at two different places characterized by a dissipative and a intermediate beaches indicate a higher variation of the sediment parameters and volume associated to the intermediate beach. (author)

  13. Screening of cellulose decomposing fungi in sandy dune soil of Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    ShaoKun Wang; XueYong Zhao; XiaoAn Zuo; XinPing Liu; Hao Qu; Wei Mao; JianYing Yun

    2015-01-01

    Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and four efficient cellulose decomposing fungi (NM3-1, NM3-2, NM3-3, and NM3-4) were screened using a CMC (carboxymethyl cellulose) carbon source in dune soil of Horqin Sandy Land. They were identified as Asperigillus calidoustus, Fusarium oxysporum, Fusarium solani, and Hypocrea lixii by rDNA-ITS molecular biological methods. Cloth decomposition rates were 15.71%, 15.89%, 17.29%, and 17.89%by the four efficient decomposers incubated for 30 days, respectively. Screening of efficient cellulose decomposers can not only increase the dune soil functional microbe bank, but can also accelerate litter decom-position and available nutrient input in the Horqin Sandy Land.

  14. Atmospheric significance of aeolian salts in the sandy deserts of northwestern China

    Directory of Open Access Journals (Sweden)

    B.-Q. Zhu

    2015-12-01

    Full Text Available Large sandy deserts in the middle latitudes of northwestern China were investigated for soluble salt variations in modern and ancient aeolian sediments, aiming to explore the environmental significance of "aeolian salts". Results revealed that aeolian salt variations have a clear relationship with the changing meridional and zonal gradients of the desert locations and the aeolian differentiation effect, but are weakly linked to local geological conditions. It suggests that the natural system of aeolian salts is hydrologically open and the chemistry of the parent brines are different from that predicted for hydrologically closed systems. Atmospheric depositions of water-soluble chemical species are an important process/source contributing to aeolian salt. Sequential variations of soluble salts in sedimentary profiles interbedded with aeolian and non-aeolian deposits and their palaeoenvironmental implications in the hinterland areas of these deserts were further evaluated, based on the constraints of OSL dating and radiocarbon dating data. The results indicate that the inorganic salts may be a latent geoproxy in revealing regional palaeoclimatic changes in desert areas for the sediments deposited under onefold depositional environment, but the interpretation should be more careful for the sediments deposited under diverse depositional conditions. This study presents the evidence of atmospheric origin of aeolian salt in sandy deserts, with limited climatic significance in palaeoenvironmental reconstruction.

  15. Influence of Particle Shape on Drag Coefficient for Commonly Occuring Sandy Particles in Coastal Areas

    Directory of Open Access Journals (Sweden)

    Chitra Arora

    2010-06-01

    Full Text Available A well defined relationship connecting settling velocity with sediment geometry and ambient properties is an essential pre-requisite for coastal and hydraulic engineering studies. An established relationship for settling velocity of sandy particles assuming spherical shape geometry is available in the literature. In reality, the sediment particles need not be spherical at all times, which influences settling velocity that is strongly biased to the drag coefficient. Based on quantitative comparison with measured data collected at Oahu Islands located in the Hawaiian archipelago, USA this work provides a relationship between drag coefficient and particle shape factor for sand grains viz; sand, sandy loam and fine sandy loam typically found in coastal environment (typical size ranges from 0.05 to 2.0 mm. The particle Reynolds number and shape factor are evaluated for each grain. The drag coefficient evaluated as function of nominal diameter and Reynolds number show a positive correlation over a wide range of shape factors used in this study. A comprehensive correlation has been developed of the drag coefficient for non-spherical particles as a function of Reynolds number and particle shape. Further a regression analysis was performed on the functional dependence of drag coefficient on particle shape. Based on this study, it could be advocated the validity of Krumbien shape factor holds well for the above characterized grain size and various particle shapes considered. Hence, the settling velocity of particles has a functional dependence on estimated drag coefficient with important implications for modeling sediment transport and swash zone hydrodynamics.

  16. Can sandy beach molluscs show an endogenously controlled circatidal migrating behaviour? Hints from a swash rig experiment

    OpenAIRE

    Vanagt, T.; Vincx, M.; Degraer, S.

    2008-01-01

    Many macrofaunal species inhabiting exposed sandy beaches are dependent on the swash for their nutrition and for migration and are highly adapted to the harsh physical conditions of the swash. The most important physical factors that determine the distribution and behaviour of swash related fauna, next to the swash itself, are sediment grain size and beach slope. Crucial swash parameters are swash period and swash velocity. Studying the influence of these factors on the animals in the field i...

  17. Three-dimensional distribution of plastic pellets in sandy beaches: shifting paradigms

    Science.gov (United States)

    Turra, Alexander; Manzano, Aruanã B.; Dias, Rodolfo Jasão S.; Mahiques, Michel M.; Barbosa, Lucas; Balthazar-Silva, Danilo; Moreira, Fabiana T.

    2014-03-01

    Plastic pellets are worldwide contaminants that accumulate in the ocean, especially in sandy beaches, where their historic standing-stock quantification relies on surface sediment samples. We demonstrated these particles present a three-dimensional instead of a simple along-across shore distribution, being found as deep as 2.0 m, with surface layers accounting for microplastics and sedimentary environments as a whole should be investigated. This poses criticism in the exactness of standing-stock records and demands urgent discussion of sampling protocols.

  18. Regime shift in sandy beach microbial communities following Deepwater Horizon oil spill remediation efforts.

    Directory of Open Access Journals (Sweden)

    Annette Summers Engel

    Full Text Available Sandy beaches support a wide variety of underappreciated biodiversity that is critical to coastal ecosystems. Prior to the 2010 Deepwater Horizon oil spill, the diversity and function of supratidal beach sediment microbial communities along Gulf of Mexico coastlines were not well understood. As such, it was unclear if microbial community compositional changes would occur following exposure to beached oil, if indigenous communities could biodegrade oil, or how cleanup efforts, such as sand washing and sediment redistribution, would impact microbial ecosystem resiliency. Transects perpendicular to the shoreline were sampled from public beaches on Grand Isle, Louisiana, and Dauphin Island, Alabama, over one year. Prior to oil coming onshore, elevated levels of bacteria associated with fecal contamination were detected (e.g., Enterobacteriales and Campylobacterales. Over time, significant shifts within major phyla were identified (e.g., Proteobacteria, Firmicutes, Actinobacteria and fecal indicator groups were replaced by taxa affiliated with open-ocean and marine systems (e.g., Oceanospirillales, Rhodospirillales, and Rhodobacterales. These new bacterial groups included putative hydrocarbon degraders, similar to those identified near the oil plume offshore. Shifts in the microbial community composition strongly correlated to more poorly sorted sediment and grain size distributional changes. Natural oceanographic processes could not account for the disrupted sediment, especially from the backshore well above the maximum high-tide levels recorded at these sites. Sand washing and tilling occurred on both open beaches from August through at least December 2010, which were mechanisms that could replace fecal indicator groups with open-ocean groups. Consequently, remediation efforts meant to return beaches to pre-spill compositions caused a regime shift that may have added potential ecosystem function, like hydrocarbon degradation, to the sediment

  19. Regime shift in sandy beach microbial communities following Deepwater Horizon oil spill remediation efforts.

    Science.gov (United States)

    Engel, Annette Summers; Gupta, Axita A

    2014-01-01

    Sandy beaches support a wide variety of underappreciated biodiversity that is critical to coastal ecosystems. Prior to the 2010 Deepwater Horizon oil spill, the diversity and function of supratidal beach sediment microbial communities along Gulf of Mexico coastlines were not well understood. As such, it was unclear if microbial community compositional changes would occur following exposure to beached oil, if indigenous communities could biodegrade oil, or how cleanup efforts, such as sand washing and sediment redistribution, would impact microbial ecosystem resiliency. Transects perpendicular to the shoreline were sampled from public beaches on Grand Isle, Louisiana, and Dauphin Island, Alabama, over one year. Prior to oil coming onshore, elevated levels of bacteria associated with fecal contamination were detected (e.g., Enterobacteriales and Campylobacterales). Over time, significant shifts within major phyla were identified (e.g., Proteobacteria, Firmicutes, Actinobacteria) and fecal indicator groups were replaced by taxa affiliated with open-ocean and marine systems (e.g., Oceanospirillales, Rhodospirillales, and Rhodobacterales). These new bacterial groups included putative hydrocarbon degraders, similar to those identified near the oil plume offshore. Shifts in the microbial community composition strongly correlated to more poorly sorted sediment and grain size distributional changes. Natural oceanographic processes could not account for the disrupted sediment, especially from the backshore well above the maximum high-tide levels recorded at these sites. Sand washing and tilling occurred on both open beaches from August through at least December 2010, which were mechanisms that could replace fecal indicator groups with open-ocean groups. Consequently, remediation efforts meant to return beaches to pre-spill compositions caused a regime shift that may have added potential ecosystem function, like hydrocarbon degradation, to the sediment. Future research will

  20. Threats to sandy beach ecosystems: A review

    Science.gov (United States)

    Defeo, Omar; McLachlan, Anton; Schoeman, David S.; Schlacher, Thomas A.; Dugan, Jenifer; Jones, Alan; Lastra, Mariano; Scapini, Felicita

    2009-01-01

    We provide a brief synopsis of the unique physical and ecological attributes of sandy beach ecosystems and review the main anthropogenic pressures acting on the world's single largest type of open shoreline. Threats to beaches arise from a range of stressors which span a spectrum of impact scales from localised effects (e.g. trampling) to a truly global reach (e.g. sea-level rise). These pressures act at multiple temporal and spatial scales, translating into ecological impacts that are manifested across several dimensions in time and space so that today almost every beach on every coastline is threatened by human activities. Press disturbances (whatever the impact source involved) are becoming increasingly common, operating on time scales of years to decades. However, long-term data sets that describe either the natural dynamics of beach systems or the human impacts on beaches are scarce and fragmentary. A top priority is to implement long-term field experiments and monitoring programmes that quantify the dynamics of key ecological attributes on sandy beaches. Because of the inertia associated with global climate change and human population growth, no realistic management scenario will alleviate these threats in the short term. The immediate priority is to avoid further development of coastal areas likely to be directly impacted by retreating shorelines. There is also scope for improvement in experimental design to better distinguish natural variability from anthropogenic impacts. Sea-level rise and other effects of global warming are expected to intensify other anthropogenic pressures, and could cause unprecedented ecological impacts. The definition of the relevant scales of analysis, which will vary according to the magnitude of the impact and the organisational level under analysis, and the recognition of a physical-biological coupling at different scales, should be included in approaches to quantify impacts. Zoning strategies and marine reserves, which have not

  1. Microbial community in a sediment-hosted CO(2) lake of the southern Okinawa Trough hydrothermal system RID C-8303-2011

    DEFF Research Database (Denmark)

    Inagaki, Fumio; Kuypers, Marcel M. M.; Tsunogai, Urumu

    2006-01-01

    Increasing levels Of CO(2) in the atmosphere are expected to cause climatic change with negative effects on the earth's ecosystems and human society. Consequently, a variety of CO(2) disposal options are discussed, including injection into the deep ocean. Because the dissolution Of CO(2) in seawa......Increasing levels Of CO(2) in the atmosphere are expected to cause climatic change with negative effects on the earth's ecosystems and human society. Consequently, a variety of CO(2) disposal options are discussed, including injection into the deep ocean. Because the dissolution Of CO(2......) in seawater will decrease ambient pH considerably, negative consequences for deep-water ecosystems have been predicted. Hence, ecosystems associated with natural Co(2) reservoirs in the deep sea, and the dynamics of gaseous, liquid, and solid CO(2) in such environments, are of great interest to science...... and society. We report here a biogeochemical and microbiological characterization of a microbial community inhabiting deep-sea sediments overlying a natural CO(2) lake at the Yonaguni Knoll IV hydrothermal field, southern Okinawa Trough. We found high abundances (> 10(9) CM(-3)) of microbial cells in sediment...

  2. Numerical modeling of the effects of Hurricane Sandy and potential future hurricanes on spatial patterns of salt marsh morphology in Jamaica Bay, New York City

    Science.gov (United States)

    Wang, Hongqing; Chen, Qin; Hu, Kelin; Snedden, Gregg A.; Hartig, Ellen K.; Couvillion, Brady R.; Johnson, Cody L.; Orton, Philip M.

    2017-03-29

    The salt marshes of Jamaica Bay, managed by the New York City Department of Parks & Recreation and the Gateway National Recreation Area of the National Park Service, serve as a recreational outlet for New York City residents, mitigate flooding, and provide habitat for critical wildlife species. Hurricanes and extra-tropical storms have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. However, the magnitude and mechanisms of hurricane effects on sediment dynamics and associated coastal wetland morphology in the northeastern United States are poorly understood. In this study, the depth-averaged version of the Delft3D modeling suite, integrated with field measurements, was utilized to examine the effects of Hurricane Sandy and future potential hurricanes on salt marsh morphology in Jamaica Bay, New York City. Hurricane Sandy-induced wind, waves, storm surge, water circulation, sediment transport, deposition, and erosion were simulated by using the modeling system in which vegetation effects on flow resistance, surge reduction, wave attenuation, and sedimentation were also incorporated. Observed marsh elevation change and accretion from a rod surface elevation table and feldspar marker horizons and cesium-137- and lead-210-derived long-term accretion rates were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model.The model results (storm surge, waves, and marsh deposition and erosion) agreed well with field measurements. The validated modeling system was then used to detect salt marsh morphological change due to Hurricane Sandy across the entire Jamaica Bay over the short-term (for example, 4 days and 1 year) and long-term (for example, 5 and 10 years). Because Hurricanes Sandy (2012) and Irene (2011) were two large and destructive tropical cyclones which hit the northeast coast, the validated coupled

  3. Hurricane Sandy science plan: coastal impact assessments

    Science.gov (United States)

    Stronko, Jakob M.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: coastal topography and bathymetry, impacts to coastal beaches and barriers, impacts of storm surge, including disturbed estuarine and bay hydrology, impacts on environmental quality and persisting contaminant exposures, impacts to coastal ecosystems, habitats, and fish and wildlife. This fact sheet focuses assessing impacts to coastal beaches and barriers.

  4. 78 FR 32296 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

    Science.gov (United States)

    2013-05-29

    ... Response to Hurricane Sandy: Response, Recovery & Resiliency AGENCY: Federal Transit Administration (FTA... recipients most severely affected by Hurricane Sandy: the Metropolitan Transportation Authority, New Jersey... Federal Register notice, bringing the total amount of Hurricane Sandy Emergency Relief funds allocated...

  5. THE BIODIVERSITY AT SANDI BIRD SANCTUARY, HARDOI WITH SPECIAL REFERENCE TO MIGRATORY BIRDS

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2013-09-01

    Full Text Available Indian subcontinent plays host to a number of migratory birds in summers as well as winters. It is estimated that over hundred species of migratory birds fly to India, either in search of feeding grounds or to escape the severe winter of their native habitat. Sandi bird sanctuary was created in 1990 in order to protect and conserve the natural habitation and surroundings and also the marine vegetation for the migratory birds, as well as for the local people of the region. The term migration is used to describe movements of populations of birds or other animals. There are three types of migrants. One way to look at migration is to consider the distances traveled. The pattern of migration can vary within each category, but is most variable in short and medium distance migrants. The origin of migration is related to the distance traveled. The birds migrating through the area, take shelter on the river front before going to the Sandi Bird sanctuary. The birds generally migrate in the winter months of October-November-December. Bird sanctuary is a popular tourist location. Sandi particularly attracts ornithologists and bird watchers, as many rare migratory birds take refuge in the sanctuary. The bird watching camps arranged to observe the migratory birds at Sandi Bird Sanctuary in the month of October and November 2012. The migratory birds at Sandi Bird Sanctuary include great crested grebe, white storks, black lbis, glossy lbis, spoonbill, ruddy shelduck, pin tail, sholveller, spot bill duck, mallard, gadwall, wigeon, tufted pochard, gargancey teal, common teal, cotton teal, grey lag goose, coot, black tailed godwit, painted stock pin tail snipe, marsh sand piper, common tern, river tern, magpie robin, white wagtail, pied wagtail, common snipe, starlings, white lbis, red crested pochard, common pochard, painted stock, black lbis, curlew, Indian skimmer etc. The resident birds at Sandi Bird Sanctuary include little grebe, darter, purple heron, grey

  6. Organic matter dynamics in coarse sandy calcareous soils

    NARCIS (Netherlands)

    Pronk, A.A.; Reuler, van H.

    2011-01-01

    The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overest

  7. Dynamics of Small-Scale Topographic Heterogeneity in European Sandy Salt Marshes

    Directory of Open Access Journals (Sweden)

    Kelly Elschot

    2016-03-01

    Full Text Available Heterogeneity can boost biodiversity, as well as increase the resilience of an ecosystem to changing environmental conditions; therefore, it is important to understand how topographic heterogeneity in ecosystems is formed. Sandy tidal marshes have a repetitive pattern of higher elevated hummocks surrounded by lower elevated depressions, representing topographic heterogeneity at the scale of a few square meters. The aims of this study were to determine when this topographic heterogeneity forms, how it is structured, and whether it persists during marsh development. The soil topography of marshes consists of coarse-grained sediment formed before marsh vegetation development, with an overlaying fine-grained sediment layer formed after initial marsh development. To gain insight into the formation of topographic heterogeneity, we studied the underlying soil topography of four European sandy marshes, where topographic heterogeneity at a scale of a few square meters was present. The differences in elevation between hummocks and depressions can either be caused by heterogeneity in the coarse-grained sediment or by heterogeneity in the top layer containing the fine-grained sediment. Our results showed that the largest percentage of elevational differences between hummocks and depressions could be attributed to heterogeneity in the underlying coarse-grained substratum. Therefore, we conclude that the patterns in all four marshes were primarily formed before marsh development, before fine-grained sediment was deposited on top of the coarse-grained sediment. However, a smaller percentage of the elevational difference between hummocks and depressions can also be explained by the presence of thicker fine-grained sediment layers on top of hummocks compared with depressions. This implies that marsh accretion rates were higher on hummocks compared with depressions. However, this result was limited to very early stages of marsh development, as marsh accretion

  8. Physical criteria for distinguishing sandy tsunami and storm deposits using modern examples

    Science.gov (United States)

    Morton, Robert A.; Gelfenbaum, Guy; Jaffe, Bruce E.

    2007-01-01

    Modern subaerial sand beds deposited by major tsunamis and hurricanes were compared at trench, transect, and sub-regional spatial scales to evaluate which attributes are most useful for distinguishing the two types of deposits. Physical criteria that may be diagnostic include: sediment composition, textures and grading, types and organization of stratification, thickness, geometry, and landscape conformity. Published reports of Pacific Ocean tsunami impacts and our field observations suggest that sandy tsunami deposits are generally 30 cm thick, generally extend The distinctions between tsunami and storm deposits are related to differences in the hydrodynamics and sediment-sorting processes during transport. Tsunami deposition results from a few high-velocity, long-period waves that entrain sediment from the shoreface, beach, and landward erosion zone. Tsunamis can have flow depths greater than 10 m, transport sediment primarily in suspension, and distribute the load over a broad region where sediment falls out of suspension when flow decelerates. In contrast, storm inundation generally is gradual and prolonged, consisting of many waves that erode beaches and dunes with no significant overland return flow until after the main flooding. Storm flow depths are commonly

  9. Microhabitat use by two rocky shore gastropods in an intertidal sandy substrate with rocky fragments.

    Science.gov (United States)

    Turra, A; Denadai, M R

    2006-02-01

    Sandy beaches in some areas of the São Sebastião Channel in southeastern Brazil have unremittingly undergone a variety of impacts, including the deposition of rock fragments in the intertidal region. Consequently, these environments support a rich fauna comprising both sandy beach and rocky shore organisms. Two rocky shore gastropods, Tegula viridula and Morula nodulosa, are particularly abundant in such environments. An evaluation of the use of microhabitats by these two species revealed that they occupy the available microhabitats in different proportions and the presence of one species is associated with the absence of the other. Morula nodulosa is randomly dispersed, occupying mostly areas with rock fragments covered with sediment and branching brown algae. Tegula viridula shows a clumped dispersion associated with the patchiness of the microhabitats used: the presence of encrusting green algae and absence of sediment and branching brown algae covering the rocks. These findings suggest T. viridula has a lower tolerance than M. nodulosa to sand inundation of the rocky fragments, a stochastic event common to the environment in question.

  10. Microhabitat use by two rocky shore gastropods in an intertidal sandy substrate with rocky fragments

    Directory of Open Access Journals (Sweden)

    A. Turra

    Full Text Available Sandy beaches in some areas of the São Sebastião Channel in southeastern Brazil have unremittingly undergone a variety of impacts, including the deposition of rock fragments in the intertidal region. Consequently, these environments support a rich fauna comprising both sandy beach and rocky shore organisms. Two rocky shore gastropods, Tegula viridula and Morula nodulosa, are particularly abundant in such environments. An evaluation of the use of microhabitats by these two species revealed that they occupy the available microhabitats in different proportions and the presence of one species is associated with the absence of the other. Morula nodulosa is randomly dispersed, occupying mostly areas with rock fragments covered with sediment and branching brown algae. Tegula viridula shows a clumped dispersion associated with the patchiness of the microhabitats used: the presence of encrusting green algae and absence of sediment and branching brown algae covering the rocks. These findings suggest T. viridula has a lower tolerance than M. nodulosa to sand inundation of the rocky fragments, a stochastic event common to the environment in question.

  11. Effects of Super Strom Sandy on Depositional Environments Offshore Long Island, New York

    Science.gov (United States)

    Hosseini, P.; McHugh, C. M.; Christensen, B. A.; Dutton, J.; Brownawell, B.; Gurung, D.

    2013-12-01

    Hurricane Sandy's landfall affected the coastlines over a broad swath of mid-Atlantic including New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. The effects included breaching, overwash and erosion of barrier islands, some of which are heavily populated and sustained extensive damage. The peak storm-tide elevation produced by Hurricane Sandy measured by USGS stations in Jamaica Bay was about 3.5 m, 1.4 m more than the historical peak-water level elevations in the same area. As part of a National Science Foundation RAPID response we sampled the sediment in West Bay, Middle Bay, East Bay, Jones Inlet and Reynolds Channel of Long Island, New York from the R/V Pritchard. The sediment sampling took place 4 months after the storm and prior to any similar large storms. The sampling strategy was designed to characterize the post-storm sedimentation in distinct depositional environments. In this survey 156 grab samples were recovered from areas, many of which had been sampled prior to the storm. The samples were analyzed for grain size variability, short-lived radioisotopes and x-ray fluorescence elemental analyses. Google Earth images from before and after the storm reveal moderate to severe erosion and overwash of the dunes in Jones inlet, and Middle and East Bays. The Long Beach barrier island tidal marshes were submerged for several days post Sandy and underwent severe erosion. The storm surge brought from offshore a layer of coarse sand that was deposited over mussel beds. Most of the mussels were dead indicative of the strength of the waves. Be-7 concentrations allowed tracking the path of the storm from the bays and inlets, to the offshore. Some of the highest Be-7 concentrations ever detected in the local estuaries: 5,329, 4,955 and 4,553 pCi/kg were measured in West Bay and Middle Bay Channels. Additionally, unusually high Be-7 concentrations of 2,130 pCi/kg were recorded ~5.24 km offshore from Long Beach barrier island four months after the

  12. Rediscovering community--reflections after Hurricane Sandy.

    Science.gov (United States)

    See, Sharon

    2013-01-01

    Hoboken, New Jersey, is a town of 50,000 residents located across the Hudson River from New York City. Most of Hoboken's infrastructure was compromised during Hurricane Sandy as a result of flooding and power outages that rendered many businesses inoperable, including all of the pharmacies in town. Despite a focus on emergency preparedness since Hurricane Katrina and 9/11, there were no contingencies in place to facilitate and assess the medication needs of the community in the event of a natural disaster. This essay describes how the author rediscovered the meaning of community, and through working with colleagues in other health care disciplines and non-health care volunteers, provided care to patients in suboptimal circumstances.

  13. Hurricane Sandy science plan: New York

    Science.gov (United States)

    Ransom, Clarice N.

    2013-01-01

    Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. More than one-half of the U.S. population lives within 50 miles of a coast, and this number is increasing. The U.S. Geological Survey (USGS) is one of the largest providers of geologic and hydrologic information in the world. Federal, State, and local partners depend on the USGS science to know how to prepare for hurricane hazards and reduce losses from future hurricanes. The USGS works closely with other bureaus within the Department of the Interior, the Federal Emergency Management Agency, the National Oceanic Atmospheric Administration, the U.S. Army Corps of Engineers, the Environmental Protection Agency, and many State and local agencies to identify their information needs before, during, and after hurricanes.

  14. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Boesen, Carsten; Kristiansen, Henning;

    1991-01-01

    Nitrate distribution and reduction processes were investigated in an unconfined sandy aquifer of Quaternary age. Groundwater chemistry was studied in a series of eight multilevel samplers along a flow line, deriving water from both arable and forested land. Results show that plumes of nitrate...... processes of O2 and NO3- occur at rates that are fast compared to the rate of downward water transport. Nitrate-contaminated groundwater contains total contents of dissolved ions that are two to four times higher than in groundwater derived from the forested area. The persistence of the high content...... of total dissolved ions in the NO3- free anoxic zone indicates the downward migration of contaminants and that active nitrate reduction is taking place. Nitrate is apparently reduced to N2 because both nitrite and ammonia are absent or found at very low concentrations. Possible electron donors...

  15. Geomorphic response of the Sandy River, Oregon, to removal of Marmot Dam

    Science.gov (United States)

    Major, Jon J.; O'Connor, Jim E.; Podolak, Charles J.; Keith, Mackenzie K.; Grant, Gordon E.; Spicer, Kurt R.; Pittman, Smokey; Bragg, Heather M.; Wallick, J. Rose; Tanner, Dwight Q.; Rhode, Abagail; Wilcock, Peter R.

    2012-01-01

    The October 2007 breaching of a temporary cofferdam constructed during removal of the 15-meter (m)-tall Marmot Dam on the Sandy River, Oregon, triggered a rapid sequence of fluvial responses as ~730,000 cubic meters (m3) of sand and gravel filling the former reservoir became available to a high-gradient river. Using direct measurements of sediment transport, photogrammetry, airborne light detection and ranging (lidar) surveys, and, between transport events, repeat ground surveys of the reservoir reach and channel downstream, we monitored the erosion, transport, and deposition of this sediment in the hours, days, and months following breaching of the cofferdam. Rapid erosion of reservoir sediment led to exceptional suspended-sediment and bedload-sediment transport rates near the dam site, as well as to elevated transport rates at downstream measurement sites in the weeks and months after breaching. Measurements of sediment transport 0.4 kilometers (km) downstream of the dam site during and following breaching show a spike in the transport of fine suspended sediment within minutes after breaching, followed by high rates of suspended-load and bedload transport of sand. Significant transport of gravel bedload past the measurement site did not begin until 18 to 20 hours after breaching. For at least 7 months after breaching, bedload transport rates just below the dam site during high flows remained as much as 10 times above rates measured upstream of the dam site and farther downstream. The elevated sediment load was derived from eroded reservoir sediment, which began eroding when a meters-tall knickpoint migrated about 200 m upstream in the first hour after breaching. Rapid knickpoint migration triggered vertical incision and bank collapse in unconsolidated sand and gravel, leading to rapid channel widening. Over the following days and months, the knickpoint migrated upstream more slowly, simultaneously decreasing in height and becoming less distinct. Within 7 months

  16. Landscape Visual Quality and Meiofauna Biodiversity on Sandy Beaches

    Science.gov (United States)

    Felix, Gabriela; Marenzi, Rosemeri C.; Polette, Marcos; Netto, Sérgio A.

    2016-10-01

    Sandy beaches are central economic assets, attracting more recreational users than other coastal ecosystems. However, urbanization and landscape modification can compromise both the functional integrity and the attractiveness of beach ecosystems. Our study aimed at investigating the relationship between sandy beach artificialization and the landscape perception by the users, and between sandy beach visual attractiveness and biodiversity. We conducted visual and biodiversity assessments of urbanized and semiurbanized sandy beaches in Brazil and Uruguay. We specifically examined meiofauna as an indicator of biodiversity. We hypothesized that urbanization of sandy beaches results in a higher number of landscape detractors that negatively affect user evaluation, and that lower-rated beach units support lower levels of biodiversity. We found that urbanized beach units were rated lower than semiurbanized units, indicating that visual quality was sensitive to human interventions. Our expectations regarding the relationship between landscape perception and biodiversity were only partially met; only few structural and functional descriptors of meiofauna assemblages differed among classes of visual quality. However, lower-rated beach units exhibited signs of lower environmental quality, indicated by higher oligochaete densities and significant differences in meiofauna structure. We conclude that managing sandy beaches needs to advance beyond assessment of aesthetic parameters to also include the structure and function of beach ecosystems. Use of such supporting tools for managing sandy beaches is particularly important in view of sea level rise and increasing coastal development.

  17. Acidification of sandy grasslands - consequences for plant diversity

    DEFF Research Database (Denmark)

    Olsson, Pål Axel; Mårtensson, Linda-Maria; Bruun, Hans Henrik

    2009-01-01

    Questions: (1) Does soil acidification in calcareous sandy grasslands lead to loss of plant diversity? (2) What is the relationship between the soil content of lime and the plant availability of mineral nitrogen (N) and phosphorus (P) in sandy grasslands? Location: Sandy glaciofluvial deposits...... in south-eastern Sweden covered by xeric sand calcareous grasslands (EU habitat directive 6120). Methods: Soil and vegetation were investigated in most of the xeric sand calcareous grasslands in the Scania region (136 sample plots distributed over four or five major areas and about 25 different sites...

  18. On the Impact Angle of Hurricane Sandy's New Jersey Landfall

    Science.gov (United States)

    Hall, Timothy M.; Sobel, Adam H.

    2013-01-01

    Hurricane Sandy's track crossed the New Jersey coastline at an angle closer to perpendicular than any previous hurricane in the historic record, one of the factors contributing to recordsetting peak-water levels in parts of New Jersey and New York. To estimate the occurrence rate of Sandy-like tracks, we use a stochastic model built on historical hurricane data from the entire North Atlantic to generate a large sample of synthetic hurricanes. From this synthetic set we calculate that under long-term average climate conditions, a hurricane of Sandy's intensity or greater (category 1+) makes NJ landfall at an angle at least as close to perpendicular as Sandy's at an average annual rate of 0.0014 yr-1 (95% confidence range 0.0007 to 0.0023); i.e., a return period of 714 years (95% confidence range 435 to 1429).

  19. 2014 USGS CMGP Lidar: Post Sandy (Long Island, NY)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Long Island New York Sandy LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00296 Woolpert...

  20. Hurricane Sandy: Rapid Response Imagery of the Surrounding Regions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of Hurricane Sandy. The aerial photography missions were conducted by the NOAA Remote Sensing Division. The images were acquired...

  1. 2008 USDA Forest Service Lidar: Sandy River Study Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. collected Light Detection and Ranging (LiDAR) data for the Sandy River study area in collaboration with the USDA Forest Service. The areas...

  2. James J. Howard Marine Sciences Laboratory @ Sandy Hook

    Data.gov (United States)

    Federal Laboratory Consortium — The James J. Howard Marine Sciences Laboratory, located on the New Jersey shore at Sandy Hook, is a state-of-the-art marine research facility shared by the National...

  3. Studies on Thiobacilli spp. isolated from sandy beaches of Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Gore, P.S.; Raveendran, O.; Unnithan, R.V.

    Occurrence, isolation and oxidative activity of Thiobacilli spp. from some sandy beaches of Kerala are reported. These organisms were encountered in polluted beaches and were dominant during monsoon in all the beaches...

  4. James J. Howard Marine Sciences Laboratory @ Sandy Hook

    Data.gov (United States)

    Federal Laboratory Consortium — The James J. Howard Marine Sciences Laboratory, located on the New Jersey shore at Sandy Hook, is a state-of-the-art marine research facility shared by the National...

  5. 2014 USGS CMGP Lidar: Sandy Restoration (Delaware and Maryland)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Extent: SANDY_Restoration_DE_MD_QL2 Area of Interest covers approximately 3.096 square miles. Lot #5 contains the full project area Dataset Description:...

  6. Extension of 239+240Pu sediment geochronology to coarse-grained marine sediments

    Science.gov (United States)

    Kuehl, Steven A.; Ketterer, Michael E.; Miselis, Jennifer L.

    2012-01-01

    Sediment geochronology of coastal sedimentary environments dominated by sand has been extremely limited because concentrations of natural and bomb-fallout radionuclides are often below the limit of measurement using standard techniques. ICP-MS analyses of 239+240Pu from two sites representative of traditionally challenging (i.e., low concentration) environments provide a "proof of concept" and demonstrate a new application for bomb-fallout radiotracers in the study of sandy shelf-seabed dynamics. A kasten core from the New Zealand shelf in the Southern Hemisphere (low fallout), and a vibracore from the sandy nearshore of North Carolina (low particle surface area) both reveal measurable 239+240Pu activities at depth. In the case of the New Zealand site, independently verified steady-state sedimentation results in a 239+240Pu profile that mimics the expected atmospheric fallout. The depth profile of 239+240Pu in the North Carolina core is more uniform, indicating significant sediment resuspension, which would be expected in this energetic nearshore environment. This study, for the first time, demonstrates the utility of 239+240Pu in the study of sandy environments, significantly extending the application of bomb-fallout isotopes to coarse-grained sediments, which compose the majority of nearshore regions.

  7. Chemistry and behaviour of B, Ca and Mg in interstitial waters of sediments from the coastal and estuarine regions of Mandovi river along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; SenGupta, R.

    processes. Salinity remains high in most of the sediments rich in clay and silt as compared to the sandy sediments, due to the semi-permeable character of clay and silt. Organic carbon in sediments (av. 1.6%) does not seem to indicate a definite relation...

  8. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface, Pre-Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  9. Evidence for the zircon origin of cadmium anomalies in bottom sediments from the littoral zone of the northern part of Lake Ladoga

    Science.gov (United States)

    Ivanter, E. V.; Slukovskii, Z. I.; Dudakova, D. S.; Medvedev, A. S.; Svetov, S. A.

    2016-06-01

    The minor-element composition of bottom sediments from the littoral zone of the northern part of Lake Ladoga was studied. Close relationships between the anomalous Cd concentrations in lake sediments and Quaternary glacial formations on the territory of Karelia were shown. A negative correlation of Cd with other heavy metals and a positive correlation with Zr were observed. Most likely, Cd is an impurity in zircons from sandy and sandy loam sedimentary formations on the northern coastal area of Lake Ladoga.

  10. Genetic Analogy Between Sediment—Hosted Gold Deposits and Sediment—Hosted Copper Deposits in Southwest China

    Institute of Scientific and Technical Information of China (English)

    肖荣阁; 陈卉泉; 等

    1996-01-01

    The sediment-hosted copper deposits according to the authors' study were formed from connate formation water during the post-sedimentary or diagenetic stage while the sediment-hosted disseminated gold deposits are unanimously considered to be of post-sedimentary hydrothermal origin.Therefore,apart from their own individulities.These two types of deposits must share some characters in common.Comparisons are attempted,in this paper,between the sediment-hosted copper deposits in southwest China and the Triassic sediment-hosted disseminated gold deposits in the Yunnan-Guizhou-Guangxi Triangle in terms of geological and geochemical features.

  11. Biodiversity and distribution of macroinfauna assemblages on sandy beaches along the Gulf of Cadiz (SW Spain

    Directory of Open Access Journals (Sweden)

    M. José Reyes-Martínez

    2015-09-01

    Full Text Available In the current study, the macroinfauna communities inhabiting 12 sandy beaches along the Spanish coast of the Gulf of Cadiz were describe in order to characterize their unexplored biodiversity, their zonation patterns and their environmental features. A total of 66 macroinfauna taxa were recorded on 12 sandy beaches, ranging from 4 to 33 species. Density reached 848 individual per m2. The individual zonation pattern ranged from two to three zones, regardless of the morphodynamic state. A common zonation pattern of the whole set of beaches was established, comprising three across-shore biological zones. Generally, the supralittoral zone was typified by the air-breathing amphipod Talitrus saltator and coleopterans; the middle zone was dominated by true intertidal species, such as Haustoriidae amphipods (Haustorius arenarius, Cirolanidae isopods (Eurydice affinis, Spionidae polychaetes (Scolelepis spp. and nemerteans; and the lower or sublittoral zone was typified by Pontoporeiidae amphipods, mysids and spionid polychaetes. Sediment moisture, average grain size, organic matter content and elevation were the main predictor variables of zonation patterns. We used the conservation and recreation potential indices to show how this information can be useful for coastal management. Most beaches studied show a score above 5 on the conservation index, so the beaches have a reasonable potential for conservation management.

  12. Zonation of macrobenthos across a mesotidal sandy beach: Variability based on physical factors

    Science.gov (United States)

    Carcedo, M. Cecilia; Fiori, Sandra M.; Bremec, Claudia S.

    2017-03-01

    The dynamic and unstable nature of sandy beaches results in a highly variable distribution of macroinfauna inhabiting the intertidal fringe. Storm-induced sediment movement on the beaches could alter the distribution of organisms, leading to an indistinct zonation scheme. In this context, the zonation pattern of macroinfauna was studied monthly during 2010 in an exposed mesotidal sandy beach on the SW Atlantic coast of Argentina (39°S). Faunal samples were collected with a plastic core (0.02 m2) at 10 to 12 levels along five replicated transects extending from above the drift line to the low tide swash zone. Sand samples were also taken at each level. Wave height and period were measured in situ and data of wind speed and direction were provided by the National Weather Service (SMN). The relationship between the formation of zonation schemes, meteorological data and the physical features of the beach were explored. The results show some significant trends: the supralittoral zone was characterized by the absence of organisms on all sampling occasions. During most of the year the zonation scheme comprised two zones, both within the littoral zone; during winter months, no zonation schemes were found. This contrasting pattern could have been determined by the harsh wind-driven waves, leading to sand movements and thus promoting variations in faunal distribution. Sedimentological changes driven by storms could therefore be the cause of a hidden zonation scheme occurring during winter months, highlighting the importance of a climatic variable in the detection of macrofaunal zonation patterns.

  13. Brazilian sandy beach macrofauna production: a review

    Directory of Open Access Journals (Sweden)

    Marcelo Petracco

    2012-12-01

    Full Text Available The state of the art of the studies on the production of Brazilian sandy beach macrofauna was analyzed on the basis of the data available in the literature. For this purpose, the representativeness of the production dataset was examined by latitudinal distribution, degree of exposure and morphodynamic state of beaches, taxonomic groups, and methods employed. A descriptive analysis was, further, made to investigate the trends in production of the more representative taxonomic groups and species of sandy beach macrofauna. A total of 69 macrofauna annual production estimates were obtained for 38 populations from 25 studies carried out between 22º56'S and 32º20'S. Production estimates were restricted to populations on beaches located on the southern and southeastern Brazilian coast. Most of the populations in the dataset inhabit exposed dissipative sandy beaches and are mainly represented by mollusks and crustaceans, with a smaller number of polychaetes. The trends in production among taxonomic groups follow a similar pattern to that observed on beaches throughout the world, with high values for bivalves and decapods. The high turnover rate (P/B ratio of the latter was due to the presence of several populations of the mole crab Emerita brasiliensis, which can attain high values of productivity, in the dataset. Most of the studies focus on the comparison of production and, especially, of P/B ratio according to life history traits in populations of the same species/taxonomic group. Despite the importance of life history-production studies, other approaches, such as the effect of man-induce disturbances on the macrofauna, should be undertaken in these threatened environments.O estado da arte dos estudos de produção da macrofauna de praias arenosas brasileiras foi analisado a partir de informações disponíveis na literatura. Para essa finalidade, a representatividade dos dados de produção foi examinada de acordo com a distribuição latitudinal

  14. Transport and distribution of bottom sediments at Pirita Beach

    Directory of Open Access Journals (Sweden)

    Soomere, Tarmo

    2007-12-01

    Full Text Available The basic factors affecting sediment supply for and transport processes at Pirita Beach, a sandy section of the south­eastern coast of Tallinn Bay, are analysed. Observations of bathymetry, sediment properties and sources, sediment transport processes and their changes arising from coastal engineering activities are reported. The mean grain size is about 0.12 mm, with the fine sand fraction (0.063–0.125 mm accounting for about 77% of the sediments. Coarse sand dominates only along the waterline. The content of coarser sediments is greater in the northern part of the beach. A number of coastal engineering structures have blocked natural sediment supplies. The beach suffers from sediment deficit now and has lost about 400 m3 of sand annually from the dry beach between 1997 and 2005.

  15. Sediment Sources in the Persian Gulf

    Science.gov (United States)

    Mahoutian, Mehrab

    2014-05-01

    Sediment Constituent Analysis is an effective tool for identifying sediment sources. Based on several sediment samples taken from different sites all over the Iranian coastlines, we have been able to show that an important portion of sediment on the beaches in the Persian Gulf is bio-clastic; that is, biologically created from the coral environment as well as other marine habitats. Unlike mineral (clastic) sediments, carbonate sediments are born not made. Furthermore, carbonate sand constituents are generally less durable than their quartz and mineral counterparts, and break down relatively quickly. Therefore, destruction of reefs and degradation of marine habitat are certain to reduce the sand supply to the shoreline in the Persian Gulf that is necessary to maintain beaches. Carbonate sands are also found on the coastline of the Oman Sea. One of the striking things about the sediments along the coastline of Iran is the high percentage of carbonate material. Molluscan debris is common, even ubiquitous. This reflects the populations living in the offshore waters. Some molluscs thrive in high-energy sandy environments, others like finer sediments. Some live at the surface, while some burrow down as much as a half-metre. A great deal of information can be gained from the study of the species of mollusk and their distribution in the sediments. This paper introduces a few case studies done in different parts of the Persian Gulf by using this method as a general assessment toolbox.

  16. Spatial variability of hydraulic conductivity of an unconfined sandy aquifer determined by a mini slug test

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Hinsby, Klaus; Christensen, Thomas Højlund;

    1992-01-01

    The spatial variability of the hydraulic conductivity in a sandy aquifer has been determined by a mini slug test method. The hydraulic conductivity (K) of the aquifer has a geometric mean of 5.05 × 10−4 m s−1, and an overall variance of 1n K equal to 0.37 which corresponds quite well to the results...... obtained by two large scale tracer experiments performed in the aquifer. A geological model of the aquifer based on 31 sediment cores, proposed three hydrogeological layers in the aquifer concurrent with the vertical variations observed with respect to hydraulic conductivity. The horizontal correlation...... length of the hydraulic conductivity has been determined for each of the three hydrogeological layers and is found to be small (1–2.5 m). The asymptotic longitudinal dispersivity of the aquifer has been estimated from the variance in hydraulic conductivity and the horizontal correlation length...

  17. The protection of sandy shores - Can we afford to ignore the contribution of seagrass?

    Science.gov (United States)

    Paul, Maike

    2017-08-15

    Shore nourishment is considered an effective soft coastal protection measure for sandy shorelines. However, sand demand and costs are high, especially as nourishment has to be repeated regularly due to ongoing erosion. Seagrass meadows are able to trap and stabilise sediment by reducing bed shear stress. Moreover, they reduce flow velocity and wave energy in regions beyond their boundaries. Especially small species may not provide these ecosystem services sufficiently to protect shorelines from erosion, but they may stabilise beach profiles enough to increase nourishment intervals. This review discusses the potential benefits of integrating ecosystem services provided by seagrass meadows, both existing and newly planted, in nourishment plans, and also addresses potential limitations such as unsuitable hydrodynamic conditions and seasonality. Finally, it highlights knowledge gaps that should be addressed by interdisciplinary research to improve nourishment plans and use seagrass ecosystem services to their full potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The importance of biological interactions for the vertical distribution of nematodes in a temperate ultra-dissipative sandy beach

    Science.gov (United States)

    Maria, Tatiana F.; Vanaverbeke, Jan; Esteves, André M.; De Troch, Marleen; Vanreusel, Ann

    2012-01-01

    This study of the vertical distribution of nematode communities in an ultra-dissipative sandy beach on the North Sea coast at De Panne, Belgium showed species-specific vertical migrations occurred over a tidal cycle. During the period of submersion, smaller deposit feeders were dominant at the subsurface, whereas large nematodes (originally classified as predators) were concentrated at the surface. The interstitial water content showed a weak correlation to the observed patterns and biological interactions among nematodes, such as predation and competition, which were measured through stable isotopes, also explained the observed segregation. The predator Enoplolaimus litoralis and its potential prey species did not co-exist in the same part of the sediment, suggesting avoidance of predation by prey species. In addition, the different prey species inhabited different subsurface layers, which can be explained by avoidance of competition for food. Stable isotope signatures further showed that the two major biological components of sandy beaches (macrofauna and meiofauna, including some species assumed to be predators) partly depend on microphytobenthos, demonstrating the importance of in situ primary producers in the diet of the fauna from ultra-dissipative sandy beaches. However, meiofauna and macrofauna do not seem to compete for these food sources. The combined examination of environmental and biological factors revealed the additional importance of the latter in controlling the vertical distribution of nematodes in environments that were previously assumed to be mainly physically controlled.

  19. Sandy River Delta Habitat Restoration Project, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Virginia; Dobson, Robin L.

    2002-11-01

    The Sandy River Delta is located at the confluence of the Sandy and Columbia Rivers, just east of Troutdale, Oregon. It comprises about 1,400 land acres north of Interstate 84, managed by the USDA Forest Service, and associated river banks managed by the Oregon Division of State Lands. Three islands, Gary, Flag and Catham, managed by Metro Greenspaces and the State of Oregon lie to the east, the Columbia River lies to the north and east, and the urbanized Portland metropolitan area lies to the west across the Sandy River. Sandy River Delta was historically a wooded, riparian wetland with components of ponds, sloughs, bottomland woodland, oak woodland, prairie, and low and high elevation floodplain. It has been greatly altered by past agricultural practices and the Columbia River hydropower system. Restoration of historic landscape components is a primary goal for this land. The Forest Service is currently focusing on restoration of riparian forest and wetlands. Restoration of open upland areas (meadow/prairie) would follow substantial completion of the riparian and wetland restoration. The Sandy River Delta is a former pasture infested with reed canary grass, blackberry and thistle. The limited over story is native riparian species such as cottonwood and ash. The shrub and herbaceous layers are almost entirely non-native, invasive species. Native species have a difficult time naturally regenerating in the thick, competing reed canary grass, Himalayan blackberry and thistle. A system of drainage ditches installed by past owners drains water from historic wetlands. The original channel of the Sandy River was diked in the 1930's, and the river diverted into the ''Little Sandy River''. The original Sandy River channel has subsequently filled in and largely become a slough. The FS acquired approximately 1,400 acres Sandy River Delta (SRD) in 1991 from Reynolds Aluminum (via the Trust for Public Lands). The Delta had been grazed for many years

  20. Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land, China

    Institute of Scientific and Technical Information of China (English)

    ChaoFeng Fu; JingBo Zhao; FanMin Mei; TianJie Shao; Jun Zuo

    2015-01-01

    Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the south-eastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that: (1) The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest: in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope. (2) Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune. (3) The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture. (4) The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indi-cating that shrubs are more effective in inhibiting wind erosion in the sandy land area.

  1. EAARL Coastal Topography - Sandy Hook 2007

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Stevens, Sara; Yates, Xan; Bonisteel, Jamie M.

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Northeast Coastal and Barrier Network, Kingston, RI; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of Gateway National Recreation Area's Sandy Hook Unit in New Jersey, acquired on May 16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL) was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then

  2. Nearshore sediment thickness, Fire Island, New York

    Science.gov (United States)

    Locker, Stanley D.; Miselis, Jennifer L.; Buster, Noreen A.; Hapke, Cheryl J.; Wadman, Heidi M.; McNinch, Jesse E.; Forde, Arnell S.; Stalk, Chelsea A.

    2017-04-03

    Investigations of coastal change at Fire Island, New York (N.Y.), sought to characterize sediment budgets and determine geologic framework controls on coastal processes. Nearshore sediment thickness is critical for assessing coastal system sediment availability, but it is largely unquantified due to the difficulty of conducting geological or geophysical surveys across the nearshore. This study used an amphibious vessel to acquire chirp subbottom profiles. These profiles were used to characterize nearshore geology and provide an assessment of nearshore sediment volume. Two resulting sediment-thickness maps are provided: total Holocene sediment thickness and the thickness of the active shoreface. The Holocene sediment section represents deposition above the maximum flooding surface that is related to the most recent marine transgression. The active shoreface section is the uppermost Holocene sediment, which is interpreted to represent the portion of the shoreface thought to contribute to present and future coastal behavior. The sediment distribution patterns correspond to previously defined zones of erosion, accretion, and stability along the island, demonstrating the importance of sediment availability in the coastal response to storms and seasonal variability. The eastern zone has a thin nearshore sediment thickness, except for an ebb-tidal deposit at the wilderness breach caused by Hurricane Sandy. Thicker sediment is found along a central zone that includes shoreface-attached sand ridges, which is consistent with a stable or accretional coastline in this area. The thickest overall Holocene section is found in the western zone of the study, where a thicker lower section of Holocene sediment appears related to the westward migration of Fire Island Inlet over several hundred years.

  3. Influence of HCl/HF treatment on organic matter in aquifer sediments: A Rock-Eval pyrolysis study

    NARCIS (Netherlands)

    Tambach, T.J.; Veld, H.; Griffioen, J.

    2009-01-01

    Rock-Eval pyrolysis is increasingly used for the routine characterization of natural organic matter in soils and sediments. In this work the bulk composition of sedimentary organic matter (SOM) in sandy aquifer sediments is studied, as well as purified samples (isolation of SOM) by HCl/HF treatment.

  4. Did Hurricane Sandy influence the 2012 US presidential election?

    Science.gov (United States)

    Hart, Joshua

    2014-07-01

    Despite drawing on a common pool of data, observers of the 2012 presidential campaign came to different conclusions about whether, how, and to what extent "October surprise" Hurricane Sandy influenced the election. The present study used a mixed correlational and experimental design to assess the relation between, and effect of, the salience of Hurricane Sandy on attitudes and voting intentions regarding President Barack Obama and Mitt Romney in a large sample of voting-aged adults. Results suggest that immediately following positive news coverage of Obama's handling of the storm's aftermath, Sandy's salience positively influenced attitudes toward Obama, but that by election day, reminders of the hurricane became a drag instead of a boon for the President. In addition to theoretical implications, this study provides an example of how to combine methodological approaches to help answer questions about the impact of unpredictable, large-scale events as they unfold.

  5. Hurricane Sandy, Disaster Preparedness, and the Recovery Model.

    Science.gov (United States)

    Pizzi, Michael A

    2015-01-01

    Hurricane Sandy was the second largest and costliest hurricane in U.S. history to affect multiple states and communities. This article describes the lived experiences of 24 occupational therapy students who lived through Hurricane Sandy using the Recovery Model to frame the research. Occupational therapy student narratives were collected and analyzed using qualitative methods and framed by the Recovery Model. Directed content and thematic analysis was performed using the 10 components of the Recovery Model. The 10 components of the Recovery Model were experienced by or had an impact on the occupational therapy students as they coped and recovered in the aftermath of the natural disaster. This study provides insight into the lived experiences and recovery perspectives of occupational therapy students who experienced Hurricane Sandy. Further research is indicated in applying the Recovery Model to people who survive disasters. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  6. Family Structures, Relationships, and Housing Recovery Decisions after Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Ali Nejat

    2016-04-01

    Full Text Available Understanding of the recovery phase of a disaster cycle is still in its infancy. Recent major disasters such as Hurricane Sandy have revealed the inability of existing policies and planning to promptly restore infrastructure, residential properties, and commercial activities in affected communities. In this setting, a thorough grasp of housing recovery decisions can lead to effective post-disaster planning by policyholders and public officials. The objective of this research is to integrate vignette and survey design to study how family bonds affected rebuilding/relocating decisions after Hurricane Sandy. Multinomial logistic regression was used to investigate respondents’ family structures before Sandy and explore whether their relationships with family members changed after Sandy. The study also explores the effect of the aforementioned relationship and its changes on households’ plans to either rebuild/repair their homes or relocate. These results were compared to another multinomial logistic regression which was applied to examine the impact of familial bonds on respondents’ suggestions to a vignette family concerning rebuilding and relocating after a hurricane similar to Sandy. Results indicate that respondents who lived with family members before Sandy were less likely to plan for relocating than those who lived alone. A more detailed examination shows that this effect was driven by those who improved their relationships with family members; those who did not improve their family relationships were not significantly different from those who lived alone, when it came to rebuilding/relocation planning. Those who improved their relationships with family members were also less likely to suggest that the vignette family relocate. This study supports the general hypothesis that family bonds reduce the desire to relocate, and provides empirical evidence that family mechanisms are important for the rebuilding/relocating decision

  7. The Scientific and Institutional Context for the Removal of Marmot Dam, Sandy River, Oregon

    Science.gov (United States)

    Grant, G. E.; Major, J. J.; O'Connor, J.; Wallick, J. R.; Marr, J.; Wilcock, P.; Podolack, C.

    2008-12-01

    Dam removal has been widely viewed as an important river restoration strategy and an interesting scientific opportunity, the latter because it represents a real-time, full-scale field experiment on fluvial adjustment. Removals therefore offer an excellent setting for testing analytical models of sediment transport, morphologic change, and our capacity to predict short- and medium-term channel evolution in response to changing water and sediment transport regimes. Most dam removals to date have involved relatively small structures and modest releases of sediment stored in pre-removal reservoirs. The largest instantaneous and uncontrolled release of sediment accompanying a dam removal occurred with the breaching of the Marmot coffer dam on the Sandy River in Oregon in October 2007. Marmot Dam was a 14-m-high by 50-m-wide diversion dam built in 1913 as part of a larger hydroelectric project. It was located on the Sandy River, an energetic gravel to cobble-bed river that naturally carries copious quantities of sand and gravel, ~45 km upstream from its confluence with the Columbia River near Portland, Oregon. At the time of removal, the reservoir upstream of the dam was completely filled with ~750,000 m3 of sand (40%) and gravel (60%). The river below the dam includes bedrock gorges, mixed bedrock/alluvial reaches, and alluvial reaches with well-developed gravel and sand bars. The decision to remove the dam was motivated by a combination of increasing maintenance costs and an unfavorable future economic return due to the necessity of installing expensive fish passage facilities to meet relicensing requirements. Portland General Electric, the dam's owner, surrendered the dam's license in 1999, and removal commenced in summer 2007. To remove the concrete structure, a temporary coffer dam was constructed 70 m upstream. In October 2007 the coffer dam was breached and the river allowed to erode the remaining impounded sediment (~730,000 m3). Physical modeling conducted at

  8. Numerical prediction on the scour burial of cylinder object freely resting on the sandy seabed in the East China Sea using the DRAMBUIE model1

    Institute of Scientific and Technical Information of China (English)

    Chong-guang PANG; Li-qian LIU; Kun LI

    2014-01-01

    After experiencing 8-day combined tidal current, circulation and wave actions, scour depth surrounding cylinder object freely resting on sandy seabed in the East China Sea (ECS) in January is numerically predicted using the DRAMBUIE model designed for scour burial, which has been widely used and verified by in-situ experiments. During the period of numerical integration, the value of time t is generally variable at every time step via the special time-stepped approach developed by this paper to eliminate the time error. The tidal current velocity, wave orbital velocity and the depth-averaged circulation in the ECS have been obtained by numerical simulations with Estuarine Coastal and Ocean Model (ECOM), Simulating Waves Nearshore (SWAN) model and Regional Ocean Modeling System (ROMS) model respectively. The control experiment and several idealized test cases on influential factors in scour depth reveal that the dominant hydrodynamic factor is tidal current in the ECS under normal weather conditions, and the impacts of shelf circulation and wave motion on local scour almost can be ignored with an exception of the Kuroshio area where the high-speed mainstream of Kuroshio flows. It is also indicated that in sandy sediments, the distribution of scour depth nearly follows the pattern of tidal currents, while the secondary influencing factor on scour depth appears to be grain size of sandy sediment in the ECS. Numerical tests on sediment grain size further testify that much finer sand is more easily scoured, and an increasing trend for scour depth with reduction of grain size is displayed due to imposed resistance of larger sized particles. Three aspects explored by this paper, including the empirical equations in the Defense Research Agency Mine Burial Environment (DRAMBUIE) model, the accuracy of inputs and infill process can severely affect the prediction of scour depth surrounding cylinder objects freely resting on sandy seabed in the ECS.

  9. Mineralogy and geochemistry of trace metals and REE in volcanic massive sulfide host rocks, stream sediments, stream waters and acid mine drainage from the Lousal mine area (Iberian Pyrite Belt, Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira da Silva, E. [GeoBioTec - GeoBiosciences, Technologies and Engineering Research Center, Departamento de Geociencias, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)], E-mail: eafsilva@ua.pt; Bobos, I. [Departamento de Geologia, Faculdade de Ciencias da Universidade do Porto, Rua Campo Alegre 687 4169-007 Porto (Portugal); Xavier Matos, J. [Centro de Estudos Geologicos e Mineiros de Beja, Rua Frei Amador Arrais No. 39 r/c, Apartado 104, 7801-902 Beja (Portugal); Patinha, C.; Reis, A.P.; Cardoso Fonseca, E. [GeoBioTec - GeoBiosciences, Technologies and Engineering Research Center, Departamento de Geociencias, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

    2009-03-15

    Acid mine drainage represents a major source of water pollution in the Lousal area. The concentrations of trace metals and the rare earth elements (REE) in the host rocks, stream sediment, surface waters and acid mine drainage (AMD) associated with abandoned mine adits and tailings impoundments were determined, in order to fingerprint their sources and to understand their mobility and water-rock interaction. The results show that the Fe-SO{sub 4}-rich acid waters vary substantially in composition both spatially and seasonally. These waters include very low pH (mostly in the range 1.9-3.0), extreme SO{sub 4} concentrations (4635-20,070 mg L{sup -1}SO{sub 4}{sup 2-}), high metal contents (Fe, Al, Cu, Zn and Mn) and very high REE contents. The trace metal concentrations decrease downstream from the discharge points either due to precipitation of neoformed phases or to dilution. The North-American shale composite (NASC)-normalized patterns corresponding to sediment from one stream (Corona stream) show a flat tendency or are slightly enriched in light-REE (LREE). The NASC-normalized patterns corresponding to acidic mine waters show enrichment in the middle REE (MREE) with respect to the LREE and heavy REE (HREE). Moreover, the REE concentrations in acidic mine waters are 2 or 3 orders of magnitude higher than those of the surface waters. Changes of REE concentrations and variation of Eu anomaly show two spatially distinct patterns: (a) pond and spring waters with higher REE concentrations (ranging from 375 to 2870 {mu}g L{sup -1}), that records conspicuous negative Eu anomaly, and (b) seeps from tailings impoundments corresponding to lower REE concentrations than the first pattern (ranging from 350 to 1139 {mu}g L{sup -1}) with typically negative Eu anomaly. The stream water samples collected from the impacted stream during the spring show a low pH (2.8-3.1) and contain high concentrations of Fe and trace elements (up to 61 mg L{sup -1}). Also, temporal variations of

  10. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Derived products of a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012...

  11. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar-extracted dune features

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Dune crest and toe positions along a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October...

  12. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Derived products of a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012 hurricane...

  13. 2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  14. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Digital elevation model (DEM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A DEM was produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012...

  15. 2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  16. STATUS, CAUSES AND COMBATING SUGGESTIONS OF SANDY DESERTIFICATION IN QINGHAI-TIBET PLATEAU

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-hua; DONG Guang-rong; LI Sen; DONG Yu-xiang

    2005-01-01

    The Qinghai-Tibet Plateau is one of the major sandy desertification regions of China. Based on the recent investigation on sandy desertification, this paper analyses the status such as the type, area, distribution and damage of sandy land desertification in the plateau. Through the analysis on the factors affecting sandy desertification in the region's natural and socio-economic systems as well as the processes and their interrelations, it can be concluded that sandy desertification in the Qinghai-Tibet Plateau resulted from the combined actions of normal natural sand drift processes, natural sandy desertification processes caused by climatic changes and man-made sandy desertification caused by improper human activities. In addition, it also predicts the possible developmental trend including the increase in desertification area and the enhancement in desertification developmental degree with the exacerbation of the complex processes, and finally puts forward some strategic suggestions to combat sandy desertification in the coming years.

  17. Origin and internal organization of widespread composite soft-sediment deformation units in a deep-water forearc basin: The lower Pleistocene Kazusa Group on the Boso Peninsula, Japan

    Science.gov (United States)

    Ogiwara, Hideaki; Ito, Makoto

    2011-06-01

    Three main types of soft-sediment deformation structures were identified in a base-of-slope and basin-plain succession (the upper Kiwada Formation) and its age-equivalent submarine slope succession (the lower Takamizo Formation) in the early Pleistocene Kazusa forearc basin on the Boso Peninsula, Japan. The three main types are (1) folded muddy deposits, (2) chaotic muddy deposits, and (3) injected sandy deposits. Chaotic muddy deposits are dominant and are intruded by sandy deposits that locally contain abundant mudstone clasts, which are poorly sorted, and are lithologically similar to debris-flow deposits. Chaotic muddy deposits in the upper Kiwada Formation are interpreted to have formed in response to downslope movements of unconsolidated surface and shallow subsurface muddy deposits, and are locally associated with folded muddy deposits in their basal part. In contrast, chaotic muddy deposits in the lower Takamizo Formation locally show a diapir-like geometry indicative of vertical intrusion, and are laterally associated with muddy deposits that are folded as a result of dragging of the host muddy sediments. In sequence-stratigraphic terms, the development of the soft-sediment deformation structures is interpreted to have occurred during a lowstand to early rise in glacioeuatatic sea-level cycles during the early Pleistocene. Although we cannot confirm which factor was the most effective triggering mechanism for the generation of the soft-sediment deformation structures in the studied successions, the interplay between (1) the seepage of methane and fossil brine, and (2) seismic shaking during the lowstand and early rise in relative sea level is interpreted to have been important in the Kazusa forearc basin during the early Pleistocene.

  18. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

    Science.gov (United States)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

    2016-08-01

    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  19. Deaths associated with Hurricane Sandy - October-November 2012.

    Science.gov (United States)

    2013-05-24

    On October 29, 2012, Hurricane Sandy hit the northeastern U.S. coastline. Sandy's tropical storm winds stretched over 900 miles (1,440 km), causing storm surges and destruction over a larger area than that affected by hurricanes with more intensity but narrower paths. Based on storm surge predictions, mandatory evacuations were ordered on October 28, including for New York City's Evacuation Zone A, the coastal zone at risk for flooding from any hurricane. By October 31, the region had 6-12 inches (15-30 cm) of precipitation, 7-8 million customers without power, approximately 20,000 persons in shelters, and news reports of numerous fatalities (Robert Neurath, CDC, personal communication, 2013). To characterize deaths related to Sandy, CDC analyzed data on 117 hurricane-related deaths captured by American Red Cross (Red Cross) mortality tracking during October 28-November 30, 2012. This report describes the results of that analysis, which found drowning was the most common cause of death related to Sandy, and 45% of drowning deaths occurred in flooded homes in Evacuation Zone A. Drowning is a leading cause of hurricane death but is preventable with advance warning systems and evacuation plans. Emergency plans should ensure that persons receive and comprehend evacuation messages and have the necessary resources to comply with them.

  20. Hurricane Sandy: An Educational Bibliography of Key Research Studies

    Science.gov (United States)

    Piotrowski, Chris

    2013-01-01

    There, undoubtedly, will be a flurry of research activity in the "Superstorm" Sandy impact area on a myriad of disaster-related topics, across academic disciplines. The purpose of this study was to review the disaster research related specifically to hurricanes in the educational and social sciences that would best serve as a compendium…

  1. Microfungi diversity isolation from sandy soil of Acapulco touristic beaches

    Science.gov (United States)

    Microscopic fungi diversity in marine sandy soil habitats is associated with key functions of beach ecosystems. There are few reports on their presence in Mexican beaches. Although standard methods to obtain the fungi from soil samples are established, the aim of this pilot study was to test the pla...

  2. 78 FR 46999 - Additional Waivers and Alternative Requirements for Hurricane Sandy Grantees in Receipt of...

    Science.gov (United States)

    2013-08-02

    ... URBAN DEVELOPMENT Additional Waivers and Alternative Requirements for Hurricane Sandy Grantees in... impacted and distressed areas declared a major disaster due to Hurricane Sandy (see 78 FR 14329, published....) (Stafford Act), due to Hurricane Sandy and other eligible events in calendar years 2011, 2012, and 2013....

  3. 77 FR 74891 - Order Granting Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy

    Science.gov (United States)

    2012-12-18

    ... COMMISSION Order Granting Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy December 12, 2012. I. Introduction Hurricane Sandy made landfall along the mid-Atlantic Coast on October 29... in the Vault at the time Hurricane Sandy made landfall, facilitating DTCC's ability to...

  4. 78 FR 33467 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

    Science.gov (United States)

    2013-06-04

    ... Response to Hurricane Sandy: Response, Recovery & Resiliency; Correction AGENCY: Federal Transit... by Hurricane Sandy. This amount was in addition to the initial $2 billion allocation announced in the... allocation restoration FTA Section 5324 Emergency Relief Program Allocations for Hurricane Sandy, by...

  5. 33 CFR 165.507 - Security Zone; Chesapeake Bay, between Sandy Point and Kent Island, MD.

    Science.gov (United States)

    2010-07-01

    ... south (eastbound) span of the William P. Lane Jr. Memorial Bridge, from the western shore at Sandy Point..., between Sandy Point and Kent Island, MD. 165.507 Section 165.507 Navigation and Navigable Waters COAST... Guard District § 165.507 Security Zone; Chesapeake Bay, between Sandy Point and Kent Island, MD. (a...

  6. Bioremediation potential of microorganisms from a sandy beach affected by a major oil spill.

    Science.gov (United States)

    Reis, Izabela; Almeida, C Marisa R; Magalhães, Catarina M; Cochofel, Jaqueline; Guedes, Paula; Basto, M Clara P; Bordalo, Adriano A; Mucha, Ana P

    2014-03-01

    The aim of this work was to evaluate the bioremediation potential of microorganisms from intertidal sediments of a sandy beach affected by a major oil spill 7 years before and subject to chronic petroleum contamination since then. For that, the response of microorganisms to a new oil contamination was assessed in terms of community structure, abundance, and capacity to degrade hydrocarbons. Experiments were carried out under laboratory-controlled conditions by mixing sediment with crude oil with three different nitrogen supplementations in 50 ml serum bottles under constant shake for 15 days. Autochthonous microorganisms were able to respond to the new oil contamination by increasing their abundance (quantified by DAPI) and changing the community structure (evaluated by DGGE). This response was particularly clear for some specific bacterial groups such as Pseudomonas, Actinomycetales, and Betaproteobacteria. These communities presented an important potential for hydrocarbon degradation (up to 85 % for TPHs and 70 % for total PAHs), being the biodegradation stimulated by addition of an appropriate amount of nitrogen.

  7. Inverse magnetic fabric in unconsolidated sandy event deposits in Kiritappu Marsh, Hokkaido, Japan

    Science.gov (United States)

    Kon, Shusaku; Nakamura, Norihiro; Nishimura, Yuichi; Goto, Kazuhisa; Sugawara, Daisuke

    2017-03-01

    Anisotropy of magnetic susceptibility (AMS) and anisotropy of anhysteretic remanence magnetization (AARM) were evaluated for samples collected from units of two unconsolidated sandy event layers, presumed to be paleo-tsunami deposits, from Kiritappu Marsh, northeastern Japan. The AARM technique isolates the fabric of fine-grained (titano)magnetite from AMS fabric of all minerals in deposits. Bulk susceptibilities of the older event layer were weaker than those of the younger event layer. Our AMS results show that the principal minimum AMS axes (Kmin) were distributed along the horizontal bedding plane, suggesting the presence of an AMS ;inverse fabric; where magnetic axes are interchanged. Our AARM results indicated the principal maximum AARM axes (kmax) are parallel to the AMS Kmin, whereas the AARM intermediate and minimum axes (kint and kmin) are related to the AMS Kmax and Kint. Moreover, the shape of anisotropy parameters revealed that the AMS is oblate (Kmax ≈ Kint), whereas the AARM is prolate (kint ≈ kmin). We found the presence of single-domain sized titanomagnetites in the mud matrix based on electron microscopy observations. AARM is regarded as a complementary tool to estimate paleocurrent directions using grain fabrics of unconsolidated sediments. However, these lines of evidence confirm that our AMS fabrics showed ;inverse fabric;, providing no information about flow directions at this locality. Although this effect is uncommon in soft sediments, it requires caution to estimate paleocurrent directions using AMS.

  8. Density and habitat dependent effects of crab burrows on sediment erodibility

    Science.gov (United States)

    Needham, Hazel R.; Pilditch, Conrad A.; Lohrer, Andrew M.; Thrush, Simon F.

    2013-02-01

    Despite biological interactions being highlighted as a key process in determining particle fluxes, relatively few studies have attempted to establish the links between burrow building bioturbators and sediment stability. The mud crab Austrohelice crassa, is a key burrowing species in New Zealand estuaries that has shown context-specific interactions with its environment. Here we use annular flumes to test if sediment stability and erodibility were altered as a function of A. crassa burrow density in two contrasting sediment types: a cohesive sandy-mud and a non-cohesive sand. Three burrow density treatments (n = 3) reflecting the natural density range in each sediment type (sand; 0-100 m- 2, sandy-mud; 0-400 m- 2), were collected from the field and subjected to sequential increases in water flow velocity. Flow profiles were measured and bed shear stresses were calculated for each treatment. Increasing burrow density reduced the mass of sediment eroded at 0.35 m s- 1(ME-35, g m- 2) in cohesive sandy-mud, while in non-cohesive sand a unimodal pattern was observed, whereby erosion rates were greatest at the lowest burrow density (19 m- 2). In the cohesive sediment, the linear decrease in erodibility with increasing burrow density was likely affected by the sluicing of fine particulates (silt-clay) from burrows when the tide was out creating both a smoothing and consolidating effect on the sediment surface. A reduction in flow velocity due to the increased presence of surficial pellets and greater trapping of bedload transported material was attributed to the reduction in the mass of sediment eroded in sand at high burrow densities. This study demonstrates that burrow builders influence sediment transport by more than just vertical particle mixing and highlights some of the complexities of small-scale sediment processes. Knowledge of different organism-sediment interactions among sediment types and spatial scales will enhance the accuracy of sediment transport models.

  9. Impact of Hurricane Sandy on the Shoreface and Inner Shelf, Offshore Long Island: Evidence for Ravinement?

    Science.gov (United States)

    Goff, J. A.; Austin, J. A.; Flood, R. D.; Schwab, W. C.; Denny, J. F.; Christensen, B. A.; Browne, C. M.; Saustrup, S.

    2013-12-01

    In January 2013, approximately two months after Hurricane Sandy made landfall in the Mid-Atlantic Bight, a scientific team from the University of Texas Institute for Geophysics, partnering with colleagues at Adelphi and Stony Brook universities and the USGS, conducted marine geophysical and surficial sampling surveys both offshore and in the inshore bays of Long Island, NY. The primary scientific goal was to assess the impact of the storm on the shoreface and inner shelf. Sandy made landfall as a post-tropical cyclone near Brigantine, NJ, with 70-kt maximum sustained winds. However, its unusual trajectory and massive size created record storm surges along the heavily-populated NJ and NY coastlines. As a result, infrastructure in the NY metropolitan area was damaged, and the Long Island barrier island system was both breached in places and elsewhere seriously eroded. The surveys included ten days of operations aboard Stony Brook's R/V Seawolf, offshore of Long Beach and Fire Island, barrier islands south of Long Island, complementing ongoing land-based studies of Sandy's impact on the NY-NJ barrier island system. Data collection involved multibeam bathymetric swath mapping, CHIRP very high resolution acoustic subbottom profiling, and surface sediment (grab) sampling to provide ground truth for the geophysical data. We surveyed regions that had been previously surveyed, both by Stony Brook in 2001 and 2005 to support reef management, and by the USGS for coastal sedimentary research, most recently in 2011 offshore Fire Island. These areas include shoreface-attached sand ridges that may be exchanging sand with the barrier island shoreface. We focus on before-and-after data comparisons on the shoreface and inner shelf, searching in particular for evidence that the storm contributed significantly to ravinement, either by wave- or current-forced erosion along the shoreface or via migration of shoreface-attached or detached sand ridges on the inner shelf. The interpreted

  10. Inner-shelf ocean dynamics and seafloor morphologic changes during Hurricane Sandy

    Science.gov (United States)

    Warner, John C.; Schwab, William C.; List, Jeffrey H.; Safak, Ilgar; Liste, Maria; Baldwin, Wayne

    2017-04-01

    Hurricane Sandy was one of the most destructive hurricanes in US history, making landfall on the New Jersey coast on October 30, 2012. Storm impacts included several barrier island breaches, massive coastal erosion, and flooding. While changes to the subaerial landscape are relatively easily observed, storm-induced changes to the adjacent shoreface and inner continental shelf are more difficult to evaluate. These regions provide a framework for the coastal zone, are important for navigation, aggregate resources, marine ecosystems, and coastal evolution. Here we provide unprecedented perspective regarding regional inner continental shelf sediment dynamics based on both observations and numerical modeling over time scales associated with these types of large storm events. Oceanographic conditions and seafloor morphologic changes are evaluated using both a coupled atmospheric-ocean-wave-sediment numerical modeling system that covered spatial scales ranging from the entire US east coast (1000 s of km) to local domains (10 s of km). Additionally, the modeled response for the region offshore of Fire Island, NY was compared to observational analysis from a series of geologic surveys from that location. The geologic investigations conducted in 2011 and 2014 revealed lateral movement of sedimentary structures of distances up to 450 m and in water depths up to 30 m, and vertical changes in sediment thickness greater than 1 m in some locations. The modeling investigations utilize a system with grid refinement designed to simulate oceanographic conditions with progressively increasing resolutions for the entire US East Coast (5-km grid), the New York Bight (700-m grid), and offshore of Fire Island, NY (100-m grid), allowing larger scale dynamics to drive smaller scale coastal changes. Model results in the New York Bight identify maximum storm surge of up to 3 m, surface currents on the order of 2 ms-1 along the New Jersey coast, waves up to 8 m in height, and bottom stresses

  11. Inner-shelf ocean dynamics and seafloor morphologic changes during Hurricane Sandy

    Science.gov (United States)

    Warner, John C.; Schwab, William C.; List, Jeffrey; Safak, Ilgar; Liste, Maria; Baldwin, Wayne E.

    2017-01-01

    Hurricane Sandy was one of the most destructive hurricanes in US history, making landfall on the New Jersey coast on Oct 30, 2012. Storm impacts included several barrier island breaches, massive coastal erosion, and flooding. While changes to the subaerial landscape are relatively easily observed, storm-induced changes to the adjacent shoreface and inner continental shelf are more difficult to evaluate. These regions provide a framework for the coastal zone, are important for navigation, aggregate resources, marine ecosystems, and coastal evolution. Here we provide unprecedented perspective regarding regional inner continental shelf sediment dynamics based on both observations and numerical modeling over time scales associated with these types of large storm events. Oceanographic conditions and seafloor morphologic changes are evaluated using both a coupled atmospheric-ocean-wave-sediment numerical modeling system and observation analysis from a series of geologic surveys and oceanographic instrument deployments focused on a region offshore of Fire Island, NY. The geologic investigations conducted in 2011 and 2014 revealed lateral movement of sedimentary structures of distances up to 450 m and in water depths up to 30 m, and vertical changes in sediment thickness greater than 1 m in some locations. The modeling investigations utilize a system with grid refinement designed to simulate oceanographic conditions with progressively increasing resolutions for the entire US East Coast (5-km grid), the New York Bight (700-m grid), and offshore of Fire Island, NY (100-m grid), allowing larger scale dynamics to drive smaller scale coastal changes. Model results in the New York Bight identify maximum storm surge of up to 3 m, surface currents on the order of 2 ms-1 along the New Jersey coast, waves up to 8 m in height, and bottom stresses exceeding 10 Pa. Flow down the Hudson Shelf Valley is shown to result in convergent sediment transport and deposition along its axis

  12. Sustainability of massively anthropic deltas via dispersal of sediment to manage land building: results from two unique case studies, the Mississippi River (U.S.A.) and the Yellow River (China) deltas

    Science.gov (United States)

    Nittrouer, Jeffrey

    2016-04-01

    Owing to their extraordinary natural resources and ecosystem services, deltaic coastlines host hundreds of millions of people worldwide. Societal sustainability on these coastal landscapes is far from certain, however, due to anthropogenic influences including sediment-supply reduction, accelerated subsidence from sub-surface fluid extraction, and leveeing of rivers. The crucial resource in building stable deltaic coastlines is sediment, and the key control on sediment delivery, whether natural or engineered, is by way river channel diversions. Two case studies, based on previous and ongoing research efforts, are presented here to describe the effects of engineered diversions for the removal of river water and associated sediment: the Mississippi River (U.S.A) and the Yellow River (China). Comparatively speaking, these two systems are end-members: Mississippi River water discharge is five times greater than the Yellow River, and yet historically, the Yellow River sediment discharges five times more sediment than the Mississippi system. As such, diversions for the two systems have contrasting goals. During flood events, the Mississippi water stage threatens major metropolitan regions with levee overtopping; spillways are therefore utilized to reduce water flux through the main channel. For the Yellow River, extremely high sediment loads result in significant sedimentation within the main channel, and so there is a concerted effort to divert and shorten the main channel, in order to enhance the water surface slope and increase sediment transport capacity. Interestingly, the net effect of these two projects has been to deposit a significant amount of sediment into the respective receiving basins, which in turn has led to the development of subaerial land. In essence, this represents two compelling case studies documenting how managed (engineered) land building practices can be implemented for other large fluvial-deltaic systems. Observational data collected from field

  13. Distributional patterns in an insect community inhabiting a sandy beach of Uruguay

    Science.gov (United States)

    Mourglia, Virginia; González-Vainer, Patricia; Defeo, Omar

    2015-12-01

    Most studies of sandy beach macrofauna have been restricted to semiterrestrial species and do not include insects when providing species richness and abundance estimates. Particularly, spatio-temporal patterns of community structure of the entomofauna inhabiting these ecosystems have been scarcely documented. This study assessed spatio-temporal distributional patterns of the night active entomofauna on a beach-dune system of Uruguay, including variations in species richness, abundance and diversity, and their relationship with environmental factors. A deconstructive taxonomic analysis was also performed, considering richness and abundance patterns separately for the most abundant insect Orders (Hymenoptera and Coleoptera) to better understand the factors which drive their patterns. We found clear temporal and across-shore patterns in the insect community inhabiting a land-ocean interface, which matched spatiotemporal variations in the environment. Abundance and species richness were highest in spring and summer, concurrently with high temperatures and low values of sediment moisture and compaction. Multivariate ordinations showed two well-defined species groups, which separated summer, autumn and spring samples from winter ones. Generalized Linear Models allowed us to describe a clear segregation in space of the most important orders of the insect community, with specific preferences for the terrestrial (Hymenoptera) and beach (Coleoptera) fringes. Hymenoptera preferred the dune zone, characterized by high elevation and low sand moisture and compaction levels, whereas Coleoptera preferred gentle slopes and fine and humid sands of the beach. Our results suggest that beach and dune ecosystems operate as two separate components in regard to their physical and biological features. The high values of species richness and abundance of insects reveal that this group has a more significant ecological role than that originally considered so far in sandy beach ecology.

  14. Morphosedimentary evolution of carbonate sandy beaches at decadal scale : case study in Reunion Island , Indian Ocean

    Science.gov (United States)

    Mahabot, Marie-Myriam; Pennober, Gwenaelle; Suanez, Serge; Troadec, Roland; Delacourt, Christophe

    2017-04-01

    Global change introduce a lot of uncertainties concerning future trajectory of beaches by directly or indirectly modifying major driving factors. An improved understanding of the past shoreline evolution may help for anticipate future coastline response. However, in tropical environment, studies concerning carbonate beaches dynamics are scarce compared to open sandy beaches. Consequently, coral reef protected beaches morphological adjustment is still poorly understood and long-term evolution rate are poorly quantified in these specific environment. In this context, La Reunion Island, insular department of France located in Indian Ocean, constitute a favoured laboratory. This high volcanic island possesses 25 km of carbonate beaches which experience hydrodynamic forcing specific from tropical environment: cyclonic swell during summer and long period swell during winter. Because of degraded coral reef health and high anthropogenic pressure, 50% of the beaches are in erosion since 1970s. Beach survey has been conducted since 1990s by scientist and are now encompassed as pilot site within a French observatory network which guarantee long-term survey with high resolution observational techniques. Thus, La Reunion Island is one of the rare carbonate beach to be surveyed since 20 years. This study aims to examined and quantify beach response at decadal scale on carbonate sandy beaches of Reunion Island. The study focus on 12 km of beaches from Cap Champagne to the Passe de Trois-Bassins. The analyze of 15 beach profile data originated from historical and DGPS beach topographic data confirm long term trend to erosion. Sediment lost varies between 0.5 and 2 m3.yr-1 since 1998. However longshore current have led to accretion of some part of beach compartment with rate of 0.7 to 1.6 m3.yr-1. Wave climate was examined from in-situ measurement over 15 years and show that extreme waves associated with tropical cyclones and long period swell play a major role in beach dynamics

  15. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size.

    Science.gov (United States)

    Rodríguez, Sara M; Valdivia, Nelson

    2017-01-01

    Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence) and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts' exposure to the parasite's dispersive stages. Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm) than large molecrabs (<15 mm). Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation-a characteristic of indirect host-parasite interactions-and subsequent increasing mortality rates over

  16. Comparative Study on Microphytobenthic Pigments and Total Microbial Biomass by ATP in Intertidal Sediments

    Directory of Open Access Journals (Sweden)

    Sun-Yong Ha

    2013-03-01

    Full Text Available Biomass and community composition of microphytobentos in tidal flats were studied by HPLC analysis and also investigated to examine the relationship between microphytobenthic pigments and Adenosine-5' triphosphate (ATP as an index of total microbial biomass in intertidal environments (muddy and sandy sediment of Gyeonggi Bay, west coast of Korea. Microphytobenthic pigments and ATP concentration in muddy sediment were the highest at the surface while the biomass of microphytobenthos in sandy sediment was the highest at the sub-surface (0.75 cm sediment depth. The detected pigments of microphytobenthos were chlorophyll a, b (euglenophytes, c3, peridinin (dinoflagellates, fucoxanthin (diatom or chrysophytes, diadinoxanthin, alloxanthin (cryptophytes, diatoxanthin, zeaxanthin (cyanobacteria, β-carotein, and pheophytin a (the degraded product of chlorophyll a. Among the pigments which were detected, the concentration of fucoxanthin was the highest, indicating that diatoms dominated in the microphytobenthic community of the tidal flats. There was little significant correlation between OC (Organic Carbon and ATP in both sediments. However, a positive correlation between chlorophyll a concentration and ATP concentration was found in sandy sediment, suggesting that microbial biomass could be affected by labile OC derived from microphytobenthos. These results provide information that may help us understand the relationship between microphytobenthos and microbial biomass in different intertidal sediment environments.

  17. Amending soils with sediment material from constructed wetlands increases phosphorus sorption

    Science.gov (United States)

    Laakso, Johanna; Uusitalo, Risto; Leppänen, Janette; Yli-Halla, Markku

    2017-04-01

    Sediment of agricultural constructed wetlands (CWs) is comprised of matter eroded from surrounding fields. This material is rich in aluminium (Al) and iron (Fe) (hydr)oxides that have a high affinity for phosphorus (P). Sediment material returned to fields could therefore affect soil P retention characteristics. We incubated a clay soil with a high soil test P (STP, 24 mg PAc l-1; extracted with pH 4.65 ammonium acetate buffer) and a sandy loam with excessive STP (210 mg PAc l-1) for three weeks with increasing amounts of CW sediment: 0, 2, 5, 10 and 50% of the sample volume. After incubation, the soil-sediment mixtures were studied with the quantity/intensity (Q/I) technique, using chemical extractions and by exposing the mixtures to simulated rainfall. Sorption affinity for P regularly increased with increasing the sediment share of the mixtures, the 0% sediment content having the lowest and 50% sediment content the highest P sorption. With 0% sediment application, the value of equilibrium P concentration (EPC0) determined by Q/I technique, was 0.69 and 44.3 mg l-1 for clay soil and sandy loam, respectively. With 2-5% sediment amendment, the EPC0 decreased 13-36% for clay soil and 13-54% for sandy loam. The 50% sediment mixtures had EPC0 of 0.05 mg l-1 for both soils. At a practically feasible sediment addition rate of 5%, dissolved reactive P (DRP) in percolating water from simulated rainfall decreased by 55% in the clay soil and 54% in sandy loam (p<0.001 in both cases). Particulate-P (PP) also showed a decreasing trend with increasing sediment addition rate. Upon prolonged simulated rainfall, the decreasing effect of sediment on DRP and PP declined somewhat. The effects of sediment addition can be attributed partly to increased salt concentrations in the sediment, which have a short-term effect on P mobilisation, but mostly to increased concentrations of Al and Fe (hydr)oxides, increasing long-term P sorption capacity. Amending the soils with sediment material

  18. The biogenic emission potential of nitric oxide from sandy soils

    Science.gov (United States)

    Yu, J. B.; Meixner, F. X.; Sun, Z. G.; Chen, X. B.; Mamtimin, B.

    2009-04-01

    There are about 160.9 Mha of sandy land in China, about 17.6% of total Chinese area, which mainly distributed in 35°-50° N. The western Songnen Plain, which located in the semi-arid region of Northeastern China, is one of the main sandy soil distribution regions. The changes of land use in sandy soil are accompanied by changes in biogeochemical cycles of nutrients, particularly of the air-surface exchange of trace gases like nitric oxide. Our study, based on results obtained by a laboratory incubation technique, focuses on (a) NO production and consumption in sandy soils from two types of land use as function of soil temperature and soil moisture, and (b) The biogenic emission potential of nitric oxide from sandy soils in semi-arid region. At 25˚C, average NO production (in terms of mass of N) was 0.016,and 0.013 ng kg-1s-1 in sandy soils from soybean land (SL) and man-made forest (MF), re¬spectively. NO consumption rate constant ranged from 0.26×10-6 to 7.28×10-6 m3 kg-1s-1. At 25˚C and under optimum soil moisture conditions for NO production, the NO compensation point mixing ratio was about 266 and 161 ug m-3 (465,and 281 ppb) for soils of SL and MF, respectively. Statistically sound relationships have been observed between NO fluxes and soil moisture (optimum curves). NO fluxes also increased exponentially with soil temperature at any given soil moisture. The optimum soil moisture for which maximum NO flux was observed was independent of soil temperature. The maximum of NO flux potentials for SL and MF soils (at 25°C) were 59.6 and 36.5 ng m-2s-1 at water-filled pore space (%WFPS) of 26 and 24, respectively. The NO flux potential was about 2 times larger for cropland soil than for man-made forest soils, most likely due to fertilizer application to the cropland soils.

  19. Landscape Change and Sandy Desertification Monitoring and Assessment

    Directory of Open Access Journals (Sweden)

    Eltahir M. Elhadi

    2009-01-01

    Full Text Available Problem statement: The objective of this study is to develop techniques for assessing and analyzing sand desertification in the northern part of Shaanxi Province, China. Approach: In order to reveal the process of land degradation, especially the latest situation of sandy desertification, a method integrating remote sensing, Geographic Information System (GIS and field survey was employed to build a sandy desertification dataset for analysis. Remote Sensing images included the Landsat Thematic Mapper (TM images in 1987 and Landsat Enhanced Thematic Mapper Plus (ETM+ images in 1999. Eight land-cover classes, including active sand dunes, fixed sand dunes, semi-fixed sand dunes, grass land, farm land, wet land, built up area and unused land and Normalized Difference Vegetation Index (NDVI, were identified. Results: The results showed that the active sand dunes and semi-fixed sand dunes have increased with a change rate of 128.70 and 55.65 km2 year-1, respectively, in the meantime the fixed sand dunes has decreased with a decreasing rate of 182.14 km2 year-1. During the 1987s, the area of sandy desertified land reached 12,006.11 km2 (57.17% of the total sandy area, of which severely desertified, medium desertified and slightly desertified land areas were 4,442.23, 4,253.45 and 3,310.43 km2, respectively. By the year 1999, the area of desertified land was increased to 13,782.30 km2 (65.63% of the total sandy area, of which severely desertified, medium desertified and slightly desertified land areas were 5,169.89, 4,918.15 and 3,694.26 km2, respectively increasing by 1,776.19 km2. Conclusion: Spatial change detection based on active sand dunes showed that the expansion area was much larger than the reversion in the past two decades and that several active sand belts has been formed, suggesting that sandy desertification of northern part of Shaanxi Province, China, will be a long-term task.

  20. Sandy Desertification Status and its Driving Mechanism in North Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang

    2004-01-01

    As the main body of Qinghai-Tibetan Plateau, North Tibet Plateau is one of three major sandy desertification regions in China and also a representative sandy desertification zone of Qinghai-Tibet Plateau. Accordingly, it is an important region for the study of recent sandy desertification processes and formation mechanism. From such aspects as desertified land types, areas and distributions etc., this paper analyses in detail the sandy desertification status on North Tibet Plateau,and qualitatively and quantitatively deals with the main factors that affect recent sandy desertification processes and the driving mechanism. Research results show that North Tibet Plateau is an important sandy desertification region in China characterized with large desertified land areas, diversified types,high severity, extensive distributions and serious damages. Sandy desertification occurrence and development resulted from combined effects of natural factors, anthropogenic factors, natural processes and man-made processes, of which climatic change is the main driving force.

  1. Cross-shore profile and coastline changes of a sandy beach in Pieria, Greece, based on measurements and numerical simulation

    Directory of Open Access Journals (Sweden)

    A.M. PROSPATHOPOULOS

    2012-12-01

    Full Text Available In the present work, the changes of cross-shore profile and the coastline of a sandy beach in Pieria, Greece, are studied by using topographic profiles, sediment analysis and a numerical simulation model. The work is motivated by the considerable erosion problems caused to an extended portion of the coast north of the studied area due to the construction of a craft shelter, and its scope is two-fold: to help in understanding the dynamics of the beach based on results of the field work and to proceed a step further, studying the responses of this beach by numerical simulation, utilizing the topographic and sediment field data and measured wave data. The study of the cross-shore profiles, as well as the sediment analysis of the samples obtained along the profiles, revealed the morphological features of the coast under study and provided information concerning the dynamic zones in each profile. The sediment grain size reduces from south to north, following the direction of the longshore currents generated in the area. The results of the numerical simulation concerning the coastline evolution are found to be in agreement with the qualitative estimations and visual observations of existing coastal changes to the broader area.

  2. Cross-shore profile and coastline changes of a sandy beach in Pieria, Greece, based on measurements and numerical simulation

    Directory of Open Access Journals (Sweden)

    A.M. PROSPATHOPOULOS

    2004-06-01

    Full Text Available In the present work, the changes of cross-shore profile and the coastline of a sandy beach in Pieria, Greece, are studied by using topographic profiles, sediment analysis and a numerical simulation model. The work is motivated by the considerable erosion problems caused to an extended portion of the coast north of the studied area due to the construction of a craft shelter, and its scope is two-fold: to help in understanding the dynamics of the beach based on results of the field work and to proceed a step further, studying the responses of this beach by numerical simulation, utilizing the topographic and sediment field data and measured wave data. The study of the cross-shore profiles, as well as the sediment analysis of the samples obtained along the profiles, revealed the morphological features of the coast under study and provided information concerning the dynamic zones in each profile. The sediment grain size reduces from south to north, following the direction of the longshore currents generated in the area. The results of the numerical simulation concerning the coastline evolution are found to be in agreement with the qualitative estimations and visual observations of existing coastal changes to the broader area.

  3. Modeling Sediment Bypassing around Rocky Headlands

    Science.gov (United States)

    George, D. A.; Largier, J. L.; Pasternack, G. B.; Erikson, L. H.; Storlazzi, C. D.; Barnard, P.

    2016-12-01

    Sediment bypassing rocky headlands remains understudied despite the importance of characterizing littoral processes and sediment budgets for erosion abatement, climate change adaptation, and beach management. This study was developed to identify controlling factors on and the mechanisms supporting sediment bypassing. Sediment flux around four idealized rocky headlands was investigated using the hydrodynamic model Delft3D and spectral wave model SWAN. The experimental design involved 120 simulations to explore the influence of headland morphology, substrate composition, sediment grain size, and oceanographic forcing. Headlands represented sizes and shapes found in natural settings, grain sizes ranged from fine to medium sand, and substrates from sandy beds to offshore bedrock reefs. The oceanography included a constructed representative tide, an alongshore background current, and four wave conditions derived from observational records in the eastern Pacific Ocean. A bypassing ratio was developed for alongshore flux between upstream and downstream cross-shore transects to determine the degree of blockage by a headland. Results showed that northwesterly oblique large waves (Hs = 7 m, Tp = 16 s) generated the most flux around headlands, whereas directly incident waves blocked flux across a headland apex. The headland shape heavily influenced the sediment fate by changing the relative angle between the shoreline and the incident waves. The bypassing ratio characterized each headland's capacity to allow alongshore flux under different wave conditions. All headlands may allow flux, although larger ones block sediment more effectively, promoting their ability to be littoral cell boundaries compared to smaller headlands. The controlling factors on sediment bypassing were determined to be wave angle, shape and size of the headland, and sediment grain size. This novel numerical modeling study advances headland modeling from the generic realm to broadly applicable classes of

  4. Geotechnical and Geoacoustic Properties of Sediments Off South Florida: Boca Raton, Indian River Beach, Lower Tampa Bay, and the Lower Florida Keys

    Science.gov (United States)

    1997-06-24

    from one to two meters (U.S. Department of Commerce, 1995). Holocene sediment thicknesses average 2.5 to 4.5 m. The Holocene sediments overlie the Key...Perry Murexflorifer dilectus A Adams It lives in a wide variety of habitats from mangrove , muddy areas to protected rocks and frequently in clear, sandy

  5. Vegetable oil spills on salt marsh sediments; comparison between sunflower and linseed oils.

    Science.gov (United States)

    Pereira, M Glória; Mudge, Stephen M; Latchford, John

    2003-09-01

    The effects of a simulated spill of sunflower oil in salt marsh sediments were compared with an experiment with linseed oil. Sunflower and linseed oil penetrated the sediments at the same rates but different adsorption of the oils onto sediment particles resulted in the establishment of anaerobic conditions at shallower depths in sediments contaminated with linseed oil than with sunflower oil. The total lipid content of sunflower oil contaminated sediments remained almost stable for 6 months, whilst only 40% of linseed oil remained in the sediment after 2 months. Numbers of culturable heterotrophic bacteria and aerobic oil degrading bacteria in muddy sediment increased rapidly in response to the presence of the oils but bacterial numbers in sandy sediments increased more slowly for sunflower oil. Changes in fatty acid composition indicate similar degradation pathways for both oils but sunflower oil degraded more slowly than linseed oil and thus has the potential for longer lasting effects in marine environments.

  6. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

    Directory of Open Access Journals (Sweden)

    Sara M. Rodríguez

    2017-08-01

    Full Text Available Background Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Methods Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts’ exposure to the parasite’s dispersive stages. Results Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm than large molecrabs (<15 mm. Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. Conclusions These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation—a characteristic of indirect host

  7. Quantifying the digital traces of Hurricane Sandy on Flickr.

    Science.gov (United States)

    Preis, Tobias; Moat, Helen Susannah; Bishop, Steven R; Treleaven, Philip; Stanley, H Eugene

    2013-11-05

    Society's increasing interactions with technology are creating extensive "digital traces" of our collective human behavior. These new data sources are fuelling the rapid development of the new field of computational social science. To investigate user attention to the Hurricane Sandy disaster in 2012, we analyze data from Flickr, a popular website for sharing personal photographs. In this case study, we find that the number of photos taken and subsequently uploaded to Flickr with titles, descriptions or tags related to Hurricane Sandy bears a striking correlation to the atmospheric pressure in the US state New Jersey during this period. Appropriate leverage of such information could be useful to policy makers and others charged with emergency crisis management.

  8. Sediment Transport

    DEFF Research Database (Denmark)

    Liu, Zhou

    Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2......, 4 and 5, respectively. It is not the intention of the book to give a broad review of the literature on this very wide topic. The book tries to pick up information which is of engineering importance. An obstacle to the study of sedimentation is the scale effect in model tests. Whenever small...

  9. Quantifying the Digital Traces of Hurricane Sandy on Flickr

    OpenAIRE

    Preis, Tobias; Moat, Helen Susannah; Bishop, Steven R.; Treleaven, Philip; Stanley, H. Eugene

    2013-01-01

    Society’s increasing interactions with technology are creating extensive “digital traces” of our collective human behavior. These new data sources are fuelling the rapid development of the new field of computational social science. To investigate user attention to the Hurricane Sandy disaster in 2012, we analyze data from Flickr, a popular website for sharing personal photographs. In this case study, we find that the number of photos taken and subsequently uploaded to Flickr with titles, desc...

  10. Brazilian sandy beaches: characteristics, ecosystem services, impacts, knowledge and priorities

    Directory of Open Access Journals (Sweden)

    Antonia Cecília Zacagnini Amaral

    Full Text Available ABSTRACT Sandy beaches constitute a key ecosystem and provide socioeconomic goods and services, thereby playing an important role in the maintenance of human populations and in biodiversity conservation. Despite the ecological and social importance of these ecosytems, Brazilian sandy beaches are significantly impacted by human interference, chemical and organic pollution and tourism, as well as global climate change. These factors drive the need to better understand the environmental change and its consequences for biota. To promote the implementation of integrated studies to detect the effects of regional and global environmental change on beaches and on other benthic habitats of the Brazilian coast, Brazilian marine researchers have established The Coastal Benthic Habitats Monitoring Network (ReBentos. In order to provide input for sample planning by ReBentos, we have conducted an intensive review of the studies conducted on Brazilian beaches and summarized the current knowledge about this environment. In this paper, we present the results of this review and describe the physical, biological and socioeconomics features of Brazilian beaches. We have used these results, our personal experience and worldwide literature to identify research projects that should be prioritized in the assessment of regional and global change on Brazilian sandy beaches. We trust that this paper will provide insights for future studies and represent a significant step towards the conservation of Brazilian beaches and their biodiversity.

  11. Aeolian processes across transverse dunes. II: Modelling the sediment transport and profile development

    NARCIS (Netherlands)

    van Dijk, P.M.; Arens, S.M.; van Boxel, J.H.

    1999-01-01

    This paper discusses a model which simulates dune development resulting from aeolian saltation transport. The model was developed for application to coastal foredunes, but is also applicable to sandy deserts with transverse dunes. Sediment transport is calculated using published deterministic and em

  12. Occurrence and activity of anammox bacteria in surface sediments of the southern North Sea

    NARCIS (Netherlands)

    Bale, N.J.; Villanueva, L.; Fan, H.; Stal, L.J.; Hopmans, E.C.; Schouten, S.; Sinninghe Damsté, J.S.

    2014-01-01

    We investigated the occurrence and activity of anaerobic ammonia oxidation (anammox) bacteria in sandy and muddy sand sediments of the southern North Sea. The presence of anammox bacteria was established through the detection of specific phosphocholine-monoether ladderane lipids, 16S rRNA gene, and

  13. Aeolian processes across transverse dunes. II: Modelling the sediment transport and profile development

    NARCIS (Netherlands)

    van Dijk, P.M.; Arens, S.M.; van Boxel, J.H.

    1999-01-01

    This paper discusses a model which simulates dune development resulting from aeolian saltation transport. The model was developed for application to coastal foredunes, but is also applicable to sandy deserts with transverse dunes. Sediment transport is calculated using published deterministic and

  14. Microalgal Photosynthesis and Spectral Scalar Irradiance in Coastal Marine-Sediments of Limfjorden, Denmark

    DEFF Research Database (Denmark)

    LASSEN, C.; PLOUG, H.; JØRGENSEN, BB

    1992-01-01

    Scalar irradiance and oxygenic photosynthesis were measured simultaneously at 100-mum spatial resolution by a fiber-optic scalar irradiance microsensor and an oxygen microelectrode spaced 120 mum apart. Marine microbial mats on sandy sediments along the coast of Limfjorden, Denmark, were dominated...

  15. Irrigation patterns in permeable sediments induced by burrow ventilation: a case study of Arenicola marina

    NARCIS (Netherlands)

    Meysman, F.J.R.; Galaktionov, O.; Middelburg, J.J.

    2005-01-01

    In sandy sediments, a strong connection exists between the physics of flow and the ecology of burrow-ventilating macrofauna. We developed a general modelling procedure that quantifies this link involving 3 steps. (1) Burrow-ventilating organisms can be described as mechanical pumps. (2) The pumping

  16. Aeolian processes across transverse dunes. II: Modelling the sediment transport and profile development

    NARCIS (Netherlands)

    van Dijk, P.M.; Arens, S.M.; van Boxel, J.H.

    1999-01-01

    This paper discusses a model which simulates dune development resulting from aeolian saltation transport. The model was developed for application to coastal foredunes, but is also applicable to sandy deserts with transverse dunes. Sediment transport is calculated using published deterministic and em

  17. Irrigation patterns in permeable sediments induced by burrow ventilation: a case study of Arenicola marina

    NARCIS (Netherlands)

    Meysman, F.J.R.; Galaktionov, O.; Middelburg, J.J.

    2005-01-01

    In sandy sediments, a strong connection exists between the physics of flow and the ecology of burrow-ventilating macrofauna. We developed a general modelling procedure that quantifies this link involving 3 steps. (1) Burrow-ventilating organisms can be described as mechanical pumps. (2) The pumping

  18. GC estimation of organic hydrocarbons that threaten shallow Quaternary sandy aquifer Northwestern Gulf of Suez, Egypt.

    Science.gov (United States)

    Zawrah, M F; Ebiad, M A; Rashad, A M; El-Sayed, E; Snousy, Moustafa Gamal; Tantawy, M A

    2014-11-01

    Soil and groundwater contamination is one of the important environmental problems at petroleum-related sites, which causes critical environmental and health defects. Severe petroleum hydrocarbon contamination from coastal refinery plant was detected in a shallow Quaternary sandy aquifer is bordered by Gulf in the Northwestern Gulf of Suez, Egypt. The overall objective of this investigation is to estimate the organic hydrocarbons in shallow sandy aquifers, released from continuous major point-source of pollution over a long period of time (91 years ago). This oil refinery contamination resulted mainly in the improper disposal of hydrocarbons and produced water releases caused by equipment failures, vandalism, and accidents that caused direct groundwater pollution or discharge into the gulf. In order to determine the fate of hydrocarbons, detailed field investigations were made to provide intensive deep profile information. Eight composite randomly sediment samples from a test plot were selected for demonstration. The tested plot was 50 m long × 50 m wide × 70 cm deep. Sediment samples were collected using an American auger around the point 29° 57' 33″ N and 32° 30' 40″ E in 2012 and covered an area of 2,500 m(2) which represents nearly 1/15 of total plant area (the total area of the plant is approximately 3.250 km(2)). The detected total petroleum hydrocarbons (TPHs) were 2.44, 2.62, 4.54, 4.78, 2.83, 3.22, 2.56, and 3.13 wt%, respectively. TPH was calculated by differences in weight and subjected to gas chromatography (GC). Hydrocarbons were analyzed on Hewlett-Packard (HP-7890 plus) gas chromatograph equipped with a flame ionization detector (FID). The percentage of paraffine of the investigated TPH samples was 7.33, 7.24, 7.58, 8.25, 10.25, 9.89, 14.77, and 17.53 wt%, respectively.

  19. Complex, dynamic combination of physical, chemical and nutritional variables controls spatio-temporal variation of sandy beach community structure.

    Science.gov (United States)

    Ortega Cisneros, Kelly; Smit, Albertus J; Laudien, Jürgen; Schoeman, David S

    2011-01-01

    Sandy beach ecological theory states that physical features of the beach control macrobenthic community structure on all but the most dissipative beaches. However, few studies have simultaneously evaluated the relative importance of physical, chemical and biological factors as potential explanatory variables for meso-scale spatio-temporal patterns of intertidal community structure in these systems. Here, we investigate macroinfaunal community structure of a micro-tidal sandy beach that is located on an oligotrophic subtropical coast and is influenced by seasonal estuarine input. We repeatedly sampled biological and environmental variables at a series of beach transects arranged at increasing distances from the estuary mouth. Sampling took place over a period of five months, corresponding with the transition between the dry and wet season. This allowed assessment of biological-physical relationships across chemical and nutritional gradients associated with a range of estuarine inputs. Physical, chemical, and biological response variables, as well as measures of community structure, showed significant spatio-temporal patterns. In general, bivariate relationships between biological and environmental variables were rare and weak. However, multivariate correlation approaches identified a variety of environmental variables (i.e., sampling session, the C∶N ratio of particulate organic matter, dissolved inorganic nutrient concentrations, various size fractions of photopigment concentrations, salinity and, to a lesser extent, beach width and sediment kurtosis) that either alone or combined provided significant explanatory power for spatio-temporal patterns of macroinfaunal community structure. Overall, these results showed that the macrobenthic community on Mtunzini Beach was not structured primarily by physical factors, but instead by a complex and dynamic blend of nutritional, chemical and physical drivers. This emphasises the need to recognise ocean-exposed sandy

  20. Complex, Dynamic Combination of Physical, Chemical and Nutritional Variables Controls Spatio-Temporal Variation of Sandy Beach Community Structure

    Science.gov (United States)

    Ortega Cisneros, Kelly; Smit, Albertus J.; Laudien, Jürgen; Schoeman, David S.

    2011-01-01

    Sandy beach ecological theory states that physical features of the beach control macrobenthic community structure on all but the most dissipative beaches. However, few studies have simultaneously evaluated the relative importance of physical, chemical and biological factors as potential explanatory variables for meso-scale spatio-temporal patterns of intertidal community structure in these systems. Here, we investigate macroinfaunal community structure of a micro-tidal sandy beach that is located on an oligotrophic subtropical coast and is influenced by seasonal estuarine input. We repeatedly sampled biological and environmental variables at a series of beach transects arranged at increasing distances from the estuary mouth. Sampling took place over a period of five months, corresponding with the transition between the dry and wet season. This allowed assessment of biological-physical relationships across chemical and nutritional gradients associated with a range of estuarine inputs. Physical, chemical, and biological response variables, as well as measures of community structure, showed significant spatio-temporal patterns. In general, bivariate relationships between biological and environmental variables were rare and weak. However, multivariate correlation approaches identified a variety of environmental variables (i.e., sampling session, the C∶N ratio of particulate organic matter, dissolved inorganic nutrient concentrations, various size fractions of photopigment concentrations, salinity and, to a lesser extent, beach width and sediment kurtosis) that either alone or combined provided significant explanatory power for spatio-temporal patterns of macroinfaunal community structure. Overall, these results showed that the macrobenthic community on Mtunzini Beach was not structured primarily by physical factors, but instead by a complex and dynamic blend of nutritional, chemical and physical drivers. This emphasises the need to recognise ocean-exposed sandy

  1. Spatial distribution of sandy desertificationchange in the west of Jilin Province

    Institute of Scientific and Technical Information of China (English)

    LIUHuiqing; XUJiawei; LVXinmiao

    2003-01-01

    The sandy land of the western part of Jilin Province is located in the ecotone of semi-humid and semi-arid area in the temperate zone of China. The sandy desertification has widely spread in the region because of the vulnerable natural conditions and the unreasonable human activity; as a result of this, the precious land resources and the economic development in the area have been seriously impacted. In this paper, the sandy land ecologic environment geographic information system is established based on the multi-spectral, multi-temporal Landsat TM images and field investigation. The comprehensive indexes of sandy desertification extent assessment which include vegetation degradation, wind erosion extent and soil depth are presented to classify the sandy land in western Jilin into three levels--slight, moderate and severe sandy desertification with the support of GIS platform. The results demonstrate that the sandy desertification has been partly controlled in the past twenty years, except some small sites. However, this doesn't necessarily mean that there is nothing for more concern. The two main causes of sandy desertification have not been eliminated yet, one is its natural factor, especially the physical and chemical characters of sandy soil and dry climate; another is the immoderate economic activity of human being that has highly accelerated the sandy desertification process.

  2. Directional analysis of the storm surge from Hurricane Sandy 2012, with applications to Charleston, New Orleans, and the Philippines.

    Directory of Open Access Journals (Sweden)

    Carl Drews

    Full Text Available Hurricane Sandy in late October 2012 drove before it a storm surge that rose to 4.28 meters above mean lower low water at The Battery in lower Manhattan, and flooded the Hugh L. Carey automobile tunnel between Brooklyn and The Battery. This study examines the surge event in New York Harbor using the Weather Research and Forecasting (WRF atmospheric model and the Coupled-Ocean-Atmosphere-Wave- Sediment Transport/Regional Ocean Modeling System (COAWST/ROMS. We present a new technique using directional analysis to calculate and display maps of a coastline's potential for storm surge; these maps are constructed from wind fields blowing from eight fixed compass directions. This analysis approximates the surge observed during Hurricane Sandy. The directional analysis is then applied to surge events at Charleston, South Carolina, New Orleans, Louisiana, and Tacloban City, the Philippines. Emergency managers could use these directional maps to prepare their cities for an approaching storm, on planning horizons from days to years.

  3. Directional analysis of the storm surge from Hurricane Sandy 2012, with applications to Charleston, New Orleans, and the Philippines.

    Science.gov (United States)

    Drews, Carl; Galarneau, Thomas J

    2015-01-01

    Hurricane Sandy in late October 2012 drove before it a storm surge that rose to 4.28 meters above mean lower low water at The Battery in lower Manhattan, and flooded the Hugh L. Carey automobile tunnel between Brooklyn and The Battery. This study examines the surge event in New York Harbor using the Weather Research and Forecasting (WRF) atmospheric model and the Coupled-Ocean-Atmosphere-Wave- Sediment Transport/Regional Ocean Modeling System (COAWST/ROMS). We present a new technique using directional analysis to calculate and display maps of a coastline's potential for storm surge; these maps are constructed from wind fields blowing from eight fixed compass directions. This analysis approximates the surge observed during Hurricane Sandy. The directional analysis is then applied to surge events at Charleston, South Carolina, New Orleans, Louisiana, and Tacloban City, the Philippines. Emergency managers could use these directional maps to prepare their cities for an approaching storm, on planning horizons from days to years.

  4. Meiofauna in sandy back-reef platforms differently exposed to the monsoons in the Maldives (Indian Ocean)

    Science.gov (United States)

    Semprucci, F.; Colantoni, P.; Sbrocca, C.; Baldelli, G.; Rocchi, M.; Balsamo, M.

    2011-09-01

    Maldives comprise some of the most characteristic and significant atoll systems, but the meiobenthic assemblages of these islands are still largely unknown. A study on meiofauna was conducted on three Maldivian sandy back-reef platforms differently exposed to stronger westerly monsoons. Clear high energy effects of the waves causing currents and erosions were observed at the completely exposed and isolated offshore reef of Thoddoo Island. Wave energy of medium intensity was confirmed at Rasdhoo by depositional structures ( finolhu), while a medium to low energy level was recorded at Gulhi on the basis of the presence of a low sandy bar. The meiofaunal assemblage counted 17 major taxa. Copepods and nematodes were dominant, followed by platyhelminthes and polychaetes. The nematode assemblage was rather rich and composed of 28 families and 84 genera. Desmodoridae were the most abundant family, followed by Draconematidae, Xyalidae, Epsilonematidae and Chromadoridae. The meiofauna resulted strongly affected by erosion effects, both in terms of abundance and richness, but we were not able to distinguish the two different sedimentation rates. Instead, the structure of the nematode community seemed to be more sensitive in distinguishing each type of hydrodynamic condition and energy level.

  5. Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments

    OpenAIRE

    Böer, S. I.; Arnosti, C.; J. E. E. van Beusekom; A. Boetius

    2009-01-01

    Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany.) Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4–5) temporal variations that were mostly related to seasonal temperature change, but also to changes in substrate availability. These temporal patterns in activity were barely reflected in bacteria...

  6. Water level response in back-barrier bays unchanged following Hurricane Sandy

    Science.gov (United States)

    Aretxabaleta, Alfredo L.; Butman, Bradford; Ganju, Neil K.

    2014-01-01

    On 28–30 October 2012, Hurricane Sandy caused severe flooding along portions of the northeast coast of the United States and cut new inlets across barrier islands in New Jersey and New York. About 30% of the 20 highest daily maximum water levels observed between 2007 and 2013 in Barnegat and Great South Bay occurred in 5 months following Hurricane Sandy. Hurricane Sandy provided a rare opportunity to determine whether extreme events alter systems protected by barrier islands, leaving the mainland more vulnerable to flooding. Comparisons between water levels before and after Hurricane Sandy at bay stations and an offshore station show no significant differences in the transfer of sea level fluctuations from offshore to either bay following Sandy. The post-Hurricane Sandy bay high water levels reflected offshore sea levels caused by winter storms, not by barrier island breaching or geomorphic changes within the bays.

  7. Biodegradation of petroleum hydrocarbons in estuarine sediments: metal influence.

    Science.gov (United States)

    Almeida, Raquel; Mucha, Ana P; Teixeira, Catarina; Bordalo, Adriano A; Almeida, C Marisa R

    2013-02-01

    In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites.

  8. Multi-level assessment of chronic toxicity of estuarine sediments with the amphipod Gammarus locusta: I. Biochemical endpoints.

    Science.gov (United States)

    Neuparth, Teresa; Correia, Ana D; Costa, Filipe O; Lima, Gláucia; Costa, Maria Helena

    2005-07-01

    We report on biomarker responses conducted as part of a multi-level assessment of the chronic toxicity of estuarine sediments to the amphipod Gammarus locusta. A companion article accounts for organism and population-level effects. Five moderately contaminated sediments from two Portuguese estuaries, Sado and Tagus, were assessed. Three of them were muddy and two were sandy sediments. The objective was to assess sediments that were not acutely toxic. Three of the sediments met this criterion, the other two were diluted (50% and 75%) with clean sediment until acute toxicity was absent. Following 28-d exposures, the amphipods were analysed for whole-body metal bioaccumulation, metallothionein induction (MT), DNA strand breakage (SB) and lipid peroxidation (LP). Two of the muddy sediments did not cause chronic toxicity. These findings were consistent with responses at organism and population levels that showed higher growth rates and improvement of reproductive traits for amphipods exposed to these two sediments. Two other sediments, one muddy and one sandy, exhibited pronounced chronic toxicity, affecting SB, MT induction (in muddy sediment), survival and reproduction. Potential toxicants involved in these effects were identified. The last sandy sediment exhibited some loss of DNA integrity, however growth was also enhanced. Present results, together with the organism/population-level data, and also benthic communities information, were analysed under a weight-of-evidence approach. By providing evidence of exposure (or lack of it) to contaminants in sediments, the biomarkers here applied assisted in distinguishing toxicants' impacts in test organisms from the confounding influence of other geochemical features of the sediments.

  9. Online Media Use and Adoption by Hurricane Sandy Affected Fire and Police Departments

    OpenAIRE

    Chauhan, Apoorva

    2014-01-01

    In this thesis work, I examine the use and adoption of online communication media by 840 fire and police departments that were affected by the 2012 Hurricane Sandy. I began by exploring how and why these fire and police departments used (or did not use) online media to communicate with the public during Hurricane Sandy. Results show that fire and police departments used online media during Hurricane Sandy to give timely and relevant information to the public about things such as evacuations, ...

  10. Morphology of rain water channelization in systematically varied model sandy soils

    OpenAIRE

    Wei, Y.; Cejas, C. M.; Barrois, R.; Dreyfus, R.; Durian, D. J.

    2014-01-01

    We visualize the formation of fingered flow in dry model sandy soils under different raining conditions using a quasi-2d experimental set-up, and systematically determine the impact of soil grain diameter and surface wetting property on water channelization phenomenon. The model sandy soils we use are random closely-packed glass beads with varied diameters and surface treatments. For hydrophilic sandy soils, our experiments show that rain water infiltrates into a shallow top layer of soil and...

  11. Regularities of wind-erosion of different land-use types in Yongding River sandy land,Beijing

    Institute of Scientific and Technical Information of China (English)

    Yue Depeng; Liu Yongbing; Zang Runguo; Wang Xian

    2006-01-01

    The threshold wind velocity of a number of variables was studied in four different land-use types:farmland,forestland,wild grassland and a flood plain in the Yongding River sandy land in Beijing.The variables studied were transport of sand, underlying surface roughness,windblown sediment,wind-sand flow structure,soil mechanical composition and amount of wind erosion.The following conclusions were drawn: 1) The order of decreasing threshold of wind speed for sand displacement and surface roughness were forestland,wild grassland,farmland,sparse wild grassland and flood plain.2) There were significant differences in sand flux among different ground covers.At a height of 0-20 cm,the height increased while the sediment discharge percent of sand flux decreased;there were significant differences in the sand flow formation under different land-use types.3) The mechanical composition of sand particles consisted mainly of silver sand in the flood plain and sparse wild grassland,and of silver sand,particle silver sand and floury sand in other land-use types.4) The amounts of wind erosion and sand sediment were different among different land-use types.Increased vegetation cover and change in farming techniques were suggested to prevent and control wind erosion of sand and soil.

  12. Microbial sewage contamination associated with Superstorm Sandy flooding in New York City

    Science.gov (United States)

    O'Mullan, G.; Dueker, M.; Sahajpal, R.; Juhl, A. R.

    2013-05-01

    The lower Hudson River Estuary commonly experiences degraded water quality following precipitation events due to the influence of combined sewer overflows. During Super-storm Sandy large scale flooding occurred in many waterfront areas of New York City, including neighborhoods bordering the Gowanus Canal and Newtown Creek Superfund sites known to frequently contain high levels of sewage associated bacteria. Water, sediment, and surface swab samples were collected from Newtown Creek and Gowanus Canal flood impacted streets and basements in the days following the storm, along with samples from the local waterways. Samples were enumerated for the sewage indicating bacterium, Enterococcus, and DNA was extracted and amplified for 16S ribosomal rRNA gene sequence analysis. Waterways were found to have relatively low levels of sewage contamination in the days following the storm. In contrast, much higher levels of Enterococci were detected in basement and storm debris samples and these bacteria were found to persist for many weeks in laboratory incubations. These data suggest that substantial sewage contamination occurred in some flood impacted New York City neighborhoods and that the environmental persistence of flood water associated microbes requires additional study and management attention.

  13. The Early Shorebird Will Catch Fewer Invertebrates on Trampled Sandy Beaches

    Science.gov (United States)

    Schlacher, Thomas A.; Carracher, Lucy K.; Porch, Nicholas; Connolly, Rod M.; Olds, Andrew D.; Gilby, Ben L.; Ekanayake, Kasun B.; Maslo, Brooke; Weston, Michael A.

    2016-01-01

    Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories. PMID:27564550

  14. Implications of Fecal Bacteria Input from Latrine-Polluted Ponds for Wells in Sandy Aquifers

    Science.gov (United States)

    Knappett, Peter S. K.; McKay, Larry D.; Layton, Alice; Williams, Daniel E.; Alam, Md. J.; Huq, Md. R.; Mey, Jacob; Feighery, John E.; Culligan, Patricia J.; Mailloux, Brian J.; Zhuang, Jie; Escamilla, Veronica; Emch, Michael; Perfect, Edmund; Sayler, Gary S.; Ahmed, Kazi M.; van Geen, Alexander

    2012-01-01

    Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5-1.3 log10/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater. PMID:22191430

  15. Change in the meiofauna community structure of sandy beaches of the Nuevo Gulf (Chubut, Argentina

    Directory of Open Access Journals (Sweden)

    Carlos A. Harguinteguy

    2012-01-01

    Full Text Available The composition and distribution of the benthic meiofauna assemblages of the Nuevo Gulf (Chubut, Argentina are described in relation to abiotic variables. The meiofauna and sediment samples were collected in the intertidal zone of four sandy beaches with different anthropic disturbances in June 2005. The samples were obtained at 20 sampling sites using a 2.5 cm diameter core tube at a depth of 10 cm. A total of 13 meiofauna taxa were identified, with the meiofauna being primarily represented by nematodes, gastrotrichs, ciliates and polychaetes and the meiofauna abundances ranging from 1.5 × 10³ to 6.5 × 10³ ind. 10 cm‑2. Univariate (one-way ANOVA test and multivariate (ANOSIM/MDS test analyses showed clear dissimilarities in community structures between sites with anthropic effects and those in pristine condition, revealed by the significant differences were found between beaches near to and far way from a city with port activity. The meiofaunal assemblage varied in abundance and diversity, and these changes in the community structure may have been related to environmental gradients on the shore. The BIO‑ENV analysis showed that the redox potential discontinuity depth might be the main factor in the spatial distribution of organisms.

  16. The Early Shorebird Will Catch Fewer Invertebrates on Trampled Sandy Beaches.

    Science.gov (United States)

    Schlacher, Thomas A; Carracher, Lucy K; Porch, Nicholas; Connolly, Rod M; Olds, Andrew D; Gilby, Ben L; Ekanayake, Kasun B; Maslo, Brooke; Weston, Michael A

    2016-01-01

    Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories.

  17. Implications of fecal bacteria input from latrine-polluted ponds for wells in sandy aquifers.

    Science.gov (United States)

    Knappett, Peter S K; McKay, Larry D; Layton, Alice; Williams, Daniel E; Alam, Md J; Huq, Md R; Mey, Jacob; Feighery, John E; Culligan, Patricia J; Mailloux, Brian J; Zhuang, Jie; Escamilla, Veronica; Emch, Michael; Perfect, Edmund; Sayler, Gary S; Ahmed, Kazi M; van Geen, Alexander

    2012-02-07

    Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond was sited within silty sand and the last in silt. The fecal indicator bacterium E. coli was rarely detected along the transects during the dry season and was only detected near the ponds extending to medium sand up to 7 m away during the monsoon. A log-linear decline in E. coli and Bacteroidales concentrations with distance along the transects in the early monsoon indicates that ponds excavated in medium sand were the likely source of contamination. Spatial removal rates ranged from 0.5 to 1.3 log(10)/m. After the ponds were artificially filled with groundwater to simulate the impact of a rain storm, E. coli levels increased near a pond recently excavated in medium sand, but no others. These observations show that adjacent sediment grain-size and how recently a pond was excavated influence the how much fecal contamination ponds receiving latrine effluents contribute to neighboring groundwater.

  18. Instream wood as a driver of nutrient attenuation in a lowland sandy stream

    Science.gov (United States)

    Klaar, Megan; Shelley, Felicity; Blaen, Phil; Dapelo, Davide; Trimmer, Mark; Bridgeman, John; Hannah, David; Krause, Stefan

    2016-04-01

    Our poster outlines our research to assess the potential of instream wood to enhance nutrient (nitrogen and carbon) attenuating potential in UK lowland rivers. Using cutting-edge distributed temperature sensing, geophysical technologies, novel microbial metabolic activity tracers and 15N isotope tracer applications, we are able to identify how instream wood alters hyporheic exchange fluxes and residence times which control the development and occurrence of biogeochemical hotspots, which facilitate nitrogen removal. Initial results show that instream wood increases surface water downwelling into the hyporheic, creating increased hyporheic mixing. Metabolic tracer, nutrient and modelling data reveal a correlation between these hyporheic exchange flow locations and increased denitrification hotspots. This data in conjunction with ongoing experimentation suggests that instream wood could be used in river basin management and river restoration efforts to improve water quality and hydromorphic integrity within lowland sandy streams. Ongoing work seeks to quantify the efficiency of alternative (stationary and transient) wood designs for controlled alteration and management of hyporheic exchange fluxes and residence times and nutrient turnover in the streambed. Outputs from this project will provide a quantitative understanding of the optimal design and efficiency of instream wood structures for removing excess nitrate from streambed sediments of nutrient impacted lowland rivers. This information will directly impact UK and European river restoration policies and inform decisions of whether wood restoration in UK lowland rivers should be promoted on a national level and how the most efficient strategies should be designed.

  19. Nesting of Phrynops geoffroanus (Testudines: Chelidae on sandy beaches along the Upper Xingu River, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo D. Ferreira Júnior

    2011-10-01

    Full Text Available This work presents the first data on incubation temperature of Phrynops geoffroanus (Schweigger, 1812 in a natural environment, and provides information on nest predation, hatching success and size of offspring born in the nests on sandy beaches along the Upper Xingu River. Thirty-one P. geoffroanus nests were found, of which eleven were completely predated, mainly by Cerdocyon thous (Linnaeus, 1766. Incubation was completed in nine out of the 17 nests protected by netting. The nests presented an average of 13.1 eggs and were distributed over the various geomorphological sectors of the nine sampled beaches. The size and weight of the hatchlings varied significantly between nests, and the incubation period in protected nests lasted for 76.5 days, less than reported for controlled incubation in the laboratory. Daily variation in incubation temperature in the three nests monitored for temperature was lower in those situated in fine sand sediments. Incubation temperature varied from 22 to 39 C and may have affected hatching success, which reached 60.8% in protected nests. Nest distribution in different geomorphological sectors indicated the plasticity of P. geoffroanus in terms of variation in nesting environment, which partly explains the species' broad geographical distribution.

  20. Analysis of the effect of Hurricane Sandy on New Jersey Atlantic coastal marshes based on landsat thematic mapper and operational land imager data: 2000-2015

    Science.gov (United States)

    Rangoonwala, Amina; Riter, J. C. Alexis; Kearney, Michael S.; Ramsey, Elijah W.

    2017-01-01

    This USGS Data Release represents geospatial data sets that were created for the analysis of the effect of Hurricane Sandy on New Jersey Atlantic Coastal Marshes. The following listed image products were generated:1) Fifteen marsh surface condition index (MSCI) data sets were calculated from yearly summer collections of ETM+ image data from 2000 to 2015. Three classes described the results of the MSCI mapping; classs1-severely impacted, class 2-moderately impacted, and class 3-intact marsh.2) Marsh change data product using Landsat images of July 14, 2011 (before) and July 19, 2013 (after) Hurricane Sandy is based on the difference in the percentage of vegetation. It shows a pattern of an increasing loss of marsh vegetation for the marshes closest to where Sandy made landfall near Brigantine, New Jersey.3) Land cover classification using Landsat TM of 14 July 2011 and 19 July 2013, 30 m spatial resolution. Eleven classes namely i) high salt marsh ii) estuarine high salt marsh iii) forested wetland iv) Phragmites australis and Spartina cynosuroides v) salt shrub scrub vi) marsh substrate from estuarine marsh area vii) marsh substrate located near lagoon viii) unconsolidated beach sediment ix) ponds and other shallow bodies on marsh x) small tidal creeks xi) urban development areasThe data release was produced in compliance with the new 'open data' requirements as a way to make the scientific products associated with USGS research efforts and publications available to the public.

  1. Benthic exchange and biogeochemical cycling in permeable sediments.

    Science.gov (United States)

    Huettel, Markus; Berg, Peter; Kostka, Joel E

    2014-01-01

    The sandy sediments that blanket the inner shelf are situated in a zone where nutrient input from land and strong mixing produce maximum primary production and tight coupling between water column and sedimentary processes. The high permeability of the shelf sands renders them susceptible to pressure gradients generated by hydrodynamic and biological forces that modulate spatial and temporal patterns of water circulation through these sediments. The resulting dynamic three-dimensional patterns of particle and solute distribution generate a broad spectrum of biogeochemical reaction zones that facilitate effective decomposition of the pelagic and benthic primary production products. The intricate coupling between the water column and sediment makes it challenging to quantify the production and decomposition processes and the resultant fluxes in permeable shelf sands. Recent technical developments have led to insights into the high biogeochemical and biological activity of these permeable sediments and their role in the global cycles of matter.

  2. Meiobenthic diversity in space and time: The case of harpacticoid copepods in two Mediterranean microtidal sandy beaches

    Science.gov (United States)

    Sevastou, Katerina; Lampadariou, Nikolaos; Eleftheriou, Anastasios

    2011-10-01

    Meiobenthic data from two microtidal sandy beaches of the eastern Mediterranean (Crete, Greece) were used to investigate patterns of both alpha and beta diversity in space and time. Copepod assemblages and environmental variables related to sediment characteristics, morphodynamics and food were studied over a year at four distinct habitats at each beach; the retention, resurgence and saturation zones of Salvat's intertidal scheme (midlittoral zone), and the surf zone of the sublittoral. Αlpha diversity analysis indicated similar species richness at both beaches when the whole 13-month data set was considered but was higher at the sheltered site when each sampling period was examined separately. Both beaches supported higher diversity in the sublittoral zone. Species richness increased seawards at the midlittoral zone of the sheltered site whereas, no pattern was evident at the exposed site, where the intense hydrodynamic conditions homogenized the sediments. Beta diversity increased markedly towards the sublittoral, indicating greater differences in alpha diversity between the sublittoral and the midlittoral zone. Species turnover was more variable at the exposed beach and at the most landward stations, where environmental conditions change often between extremes. A proportion of the variation in alpha diversity was explained by food availability at both beaches and additionally by grain size at the sheltered site. However, no environmental variable explained beta diversity patterns. Although the results of our study support the hypothesis of Multicausal Environmental Severity proposed for sandy beach macrofauna, we believe the classic Intermediate Disturbance Hypothesis is a more appropriate framework for the meiofauna communities of the studied sites.

  3. Port redesign and planned beach renourishment in a high wave energy sandy-muddy coastal environment, Port Gisborne, New Zealand

    Science.gov (United States)

    Healy, Terry; Stephens, Scott; Black, Kerry; Gorman, Richard; Cole, Russell; Beamsley, Brett

    2002-11-01

    Redesign of Port Gisborne for the 21st century has encompassed a broad interdisciplinary approach. This procedure has taken into account the operational requirements of the port, effects of dredging and construction upon the benthic fauna, and wave activity within the port confines after the proposed development. Added amenity value of the development to the local community is an important ancillary redesign consideration. Initially, a major research project into the environmental impacts of the developments has been undertaken. The project, which commenced in 1996 and is still continuing, involves an iterative approach integrating the initial design and development options with the operational feasibility, construction constraints, environmental constraints, social acceptability, and economic practicality of the port; all of these require in-depth assessment to obtain the necessary planning and development approvals. This requires close liaison between the professional environmental research scientists, port management, port operation staff (pilots), construction engineers, planners, and the community interest groups. Numerical modelling of the hydrodynamics of Poverty Bay, simulating waves and current effects on the various initial designs options, and calibrated against data from a substantial field program, has been a fundamental tool. It was applied experimentally to determine the best option for the port layout, as well as to assess sedimentation impacts. Modelling results indicated a significant increase in maintenance dredging expected as a result of deepening the navigation approach channel. Because this may have an impact on the nearby sandy beach by inducing erosion, the best option for disposal of the sandy dredged material was determined to be disposal in the surf zone for subtidal beach profile renourishment. Textural analysis of the sediments trapped in the navigation channel demonstrated that they were suitable for this purpose.

  4. Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms

    Directory of Open Access Journals (Sweden)

    Rebecca M. Schwartz

    2017-08-01

    Full Text Available Hurricane Sandy hit the eastern coast of the United States in October 2012, causing billions of dollars in damage and acute physical and mental health problems. The long-term mental health consequences of the storm and their predictors have not been studied. New York City and Long Island residents completed questionnaires regarding their initial Hurricane Sandy exposure and mental health symptoms at baseline and 1 year later (N = 130. There were statistically significant decreases in anxiety scores (mean difference = −0.33, p < 0.01 and post-traumatic stress disorder (PTSD scores (mean difference = −1.98, p = 0.001 between baseline and follow-up. Experiencing a combination of personal and property damage was positively associated with long-term PTSD symptoms (ORadj 1.2, 95% CI [1.1–1.4] but not with anxiety or depression. Having anxiety, depression, or PTSD at baseline was a significant predictor of persistent anxiety (ORadj 2.8 95% CI [1.1–6.8], depression (ORadj 7.4 95% CI [2.3–24.1 and PTSD (ORadj 4.1 95% CI [1.1–14.6] at follow-up. Exposure to Hurricane Sandy has an impact on PTSD symptoms that persists over time. Given the likelihood of more frequent and intense hurricanes due to climate change, future hurricane recovery efforts must consider the long-term effects of hurricane exposure on mental health, especially on PTSD, when providing appropriate assistance and treatment.

  5. Emergency evacuation orders: considerations and lessons from Hurricane Sandy.

    Science.gov (United States)

    O'Neil, Patrick D

    2014-01-01

    This article analyzes the problems surrounding the execution of emergency evacuation orders by evaluating Hurricane Sandy and the emergency actions taken by the State of New Jersey and the City of Atlantic City New Jersey. The analysis provides an overview of the legal authority granting emergency powers to governors and mayors to issue evacuation proclamations in addition to an evaluation of the New Jersey's emergency evacuation mandate and subsequent compliance. The article concludes with provision of planning and preparedness recommendations for public managers facing similar hazards, including a recommendation for provision of emergency shelter contingencies within the threat zone in anticipation of citizen noncompliance evacuation orders.

  6. Measured and Estimated Volatilisation of Naphthalene from a Sandy Soil

    DEFF Research Database (Denmark)

    Lindhardt, Bo; Christensen, Thomas Højlund

    1994-01-01

    The non-steady-state fluxes of naphthalene from an artificially contaminated sandy soil at different water contents were measured in the laboratory, at 10°C. The soil contained 1.1% of organic carbon and the water content varied between 2.8 and 14% w/w. The diffusive flux of naphthalene from the ...... the fluxes by a factor of 1.5 to 6.4. The largest deviation between predicted and observed dynamic fluxes was found at high water contents. For the cover soil, half-life times of 1 to 2 days were estimated by the model for naphthalene degradation....

  7. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.

    2010-01-01

    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  8. Coastline evolution of Portuguese low-lying sandy coast in the last 50 years: an integrated approach

    Science.gov (United States)

    Ponte Lira, Cristina; Nobre Silva, Ana; Taborda, Rui; Freire de Andrade, Cesar

    2016-06-01

    Regional/national-scale information on coastline rates of change and trends is extremely valuable, but these studies are scarce. A widely accepted standardized methodology for analysing long-term coastline change has been difficult to achieve, but it is essential to conduct an integrated and holistic approach to coastline evolution and hence support coastal management actions. Additionally, databases providing knowledge on coastline evolution are of key importance to support both coastal management experts and users.The main objective of this work is to present the first systematic, national-scale and consistent long-term coastline evolution data of Portuguese mainland low-lying sandy coasts.The methodology used quantifies coastline evolution using a unique and robust coastline indicator (the foredune toe), which is independent of short-term changes.The dataset presented comprises (1) two polyline sets, mapping the 1958 and 2010 sandy beach-dune system coastline, both optimized for working at 1 : 50 000 scale or smaller; (2) one polyline set representing long-term change rates between 1958 and 2010, each estimated at 250 m; and (3) a table with minimum, maximum and mean of evolution rates for sandy beach-dune system coastline. All science data produced here are openly accessible at https://doi.pangaea.de/10.1594/PANGAEA.859136" target="_blank">https://doi.pangaea.de/10.1594/PANGAEA.859136 and can be used in other studies.Results show beach erosion as the dominant trend, with a mean change rate of -0.24 ± 0.01 m year-1 for all mainland Portuguese beach-dune systems. Although erosion is dominant, this evolution is variable in signal and magnitude in different coastal sediment cells and also within each cell. The most relevant beach erosion issues were found in the coastal stretches of Espinho-Torreira and Costa Nova-Praia de Mira, Cova da Gala-Leirosa, and Cova do Vapor-Costa da Caparica. The coastal segments Minho River-Nazaré and Costa da Caparica adjacent to the

  9. Multiple ash layers in late Quaternary sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas-Pereira, M.B.L.; Nath, B.N.; Iyer, S.D.; Borole, D.V.; Parthiban, G.; Jijin, R.; Khedekar, V.D.

    and dispersed shards. Rhyolitic glass shards of bubble wall, platy, angular and blocky types were retrieved from various stratigraphic horizons in the cores. The abundance of glass shards, composition of bulk sediments, and 230Thexcess ages of the host sediments...

  10. Microcystin elimination during sediment contact.

    Science.gov (United States)

    Grützmacher, Gesche; Wessel, Gabriele; Klitzke, Sondra; Chorus, Ingrid

    2010-01-15

    Microcystins (MCYSTs) are a group of structurally similar toxic peptides produced by cyanobacteria ("blue-green algae") which occur frequently in surface waters worldwide. Reliable elimination is necessary when using these waters as drinking water sources. Bank filtration and artificial groundwater recharge utilize adsorption and degradation processes in the subsurface, commonly through sand and gravel aquifers, for the elimination of a wide range of substances during drinking water (pre-) treatment. To obtain parameters for estimating whether MCYST breakthrough is likely in field settings, we tested MCYST elimination in laboratory experiments (batch experiments, column experiments) under a range of conditions. Adsorption coefficients (k(d)-values) obtained from batch studies ranged from 0.2 mL/g for filter sand to 11.6 mL/g for fine grained aquifer materials with 2% fine grains (<63 microm) and 0.8% organic matter. First order degradation rates in column studies reached 1.87 d(-1) under aerobic conditions and showed high variations under anoxic conditions (<0.01-1.35 d(-1)). These results show that, next to sediment texture, redox conditions play an important role for MCYST elimination during sediment passage. Biodegradation was identified as the dominating process for MCYST elimination in sandy aquifer material.

  11. Interactive effects of vegetation and sediment properties on erosion of salt marshes in the Northern Adriatic Sea.

    Science.gov (United States)

    Lo, V B; Bouma, T J; van Belzen, J; Van Colen, C; Airoldi, L

    2017-09-12

    We investigated how lateral erosion control, measured by novel photogrammetry techniques, is modified by the presence of Spartina spp. vegetation, sediment grain size, and the nutrient status of salt marshes across 230 km of the Italian Northern Adriatic coastline. Spartina spp. vegetation reduced erosion across our study sites. The effect was more pronounced in sandy soils, where erosion was reduced by 80% compared to 17% in silty soils. Erosion resistance was also enhanced by Spartina spp. root biomass. In the absence of vegetation, erosion resistance was enhanced by silt content, with mean erosion 72% lower in silty vs. sandy soils. We found no relevant relationships with nutrient status, likely due to overall high nutrient concentrations and low C:N ratios across all sites. Our results contribute to quantifying coastal protection ecosystem services provided by salt marshes in both sandy and silty sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Environmental mechanism of magnetic susceptibility changes of lacustrine sediments from Lake Hulun, China

    Institute of Scientific and Technical Information of China (English)

    胡守云; 王苏民; Erwin; Appel; 吉磊

    2000-01-01

    The changes of magnetic susceptibility (κ) are correlated with those of corresponding sedimentological, geochemical, mineralogical and biological results, which verifies that κ can be taken as one of the environmental proxies. However, usually the exact origin of magnetic signal is poorly understood, and is difficult to relate with the environmental evolution. Magnetic properties of material derived from the catchment and sedimentary environment may affect the accumulation, preservation, or authigenesis and diagenesis of magnetic minerals. In the Lake Hulun region in Inner Mongolia, it is found that muddy sediments, deposited during high water level period (corresponding to humid climate), have comparatively high κ values. In contrast, the sandy sediments, deposited during low water level period (corresponding to arid climate), have low κ values. Detailed rock magnetic investigation confirms that detrital magnetite derived from volcanic rocks in the catchment exists in both muddy and sandy sediments

  13. The impact of Hurricane Sandy on the shoreface and inner shelf of Fire Island, New York: Large bedform migration but limited erosion

    Science.gov (United States)

    Goff, John A.; Flood, Roger D.; Austin, James A., Jr.; Schwab, William C.; Christensen, Beth; Browne, Cassandra M.; Denny, Jane F.; Baldwin, Wayne E.

    2015-04-01

    We investigate the impact of superstorm Sandy on the lower shoreface and inner shelf offshore the barrier island system of Fire Island, NY using before-and-after surveys involving swath bathymetry, backscatter and CHIRP acoustic reflection data. As sea level rises over the long term, the shoreface and inner shelf are eroded as barrier islands migrate landward; large storms like Sandy are thought to be a primary driver of this largely evolutionary process. The "before" data were collected in 2011 by the U.S. Geological Survey as part of a long-term investigation of the Fire Island barrier system. The "after" data were collected in January, 2013, ~two months after the storm. Surprisingly, no widespread erosional event was observed. Rather, the primary impact of Sandy on the shoreface and inner shelf was to force migration of major bedforms (sand ridges and sorted bedforms) 10's of meters WSW alongshore, decreasing in migration distance with increasing water depth. Although greater in rate, this migratory behavior is no different than observations made over the 15-year span prior to the 2011 survey. Stratigraphic observations of buried, offshore-thinning fluvial channels indicate that long-term erosion of older sediments is focused in water depths ranging from the base of the shoreface (~13-16 m) to ~21 m on the inner shelf, which is coincident with the range of depth over which sand ridges and sorted bedforms migrated in response to Sandy. We hypothesize that bedform migration regulates erosion over these water depths and controls the formation of a widely observed transgressive ravinement; focusing erosion of older material occurs at the base of the stoss (upcurrent) flank of the bedforms. Secondary storm impacts include the formation of ephemeral hummocky bedforms and the deposition of a mud event layer.

  14. The impact of Hurricane Sandy on the shoreface and inner shelf of Fire Island, New York: large bedform migration but limited erosion

    Science.gov (United States)

    Goff, John A.; Flood, Roger D.; Austin, James A.; Schwab, William C.; Christensen, Beth A.; Browne, Cassandra M.; Denny, Jane F.; Baldwin, Wayne E.

    2015-01-01

    We investigate the impact of superstorm Sandy on the lower shoreface and inner shelf offshore the barrier island system of Fire Island, NY using before-and-after surveys involving swath bathymetry, backscatter and CHIRP acoustic reflection data. As sea level rises over the long term, the shoreface and inner shelf are eroded as barrier islands migrate landward; large storms like Sandy are thought to be a primary driver of this largely evolutionary process. The “before” data were collected in 2011 by the U.S. Geological Survey as part of a long-term investigation of the Fire Island barrier system. The “after” data were collected in January, 2013, ~two months after the storm. Surprisingly, no widespread erosional event was observed. Rather, the primary impact of Sandy on the shoreface and inner shelf was to force migration of major bedforms (sand ridges and sorted bedforms) 10’s of meters WSW alongshore, decreasing in migration distance with increasing water depth. Although greater in rate, this migratory behavior is no different than observations made over the 15-year span prior to the 2011 survey. Stratigraphic observations of buried, offshore-thinning fluvial channels indicate that long-term erosion of older sediments is focused in water depths ranging from the base of the shoreface (~13–16 m) to ~21 m on the inner shelf, which is coincident with the range of depth over which sand ridges and sorted bedforms migrated in response to Sandy. We hypothesize that bedform migration regulates erosion over these water depths and controls the formation of a widely observed transgressive ravinement; focusing erosion of older material occurs at the base of the stoss (upcurrent) flank of the bedforms. Secondary storm impacts include the formation of ephemeral hummocky bedforms and the deposition of a mud event layer.

  15. Magnetism of quaternary sediments

    Science.gov (United States)

    Heller, Friedrich

    Magnetism of Quaternary sediments was the topic of a well-attended symposium held during the 13th INQUA (International Union of Quaternary Research) congress in Beijing, China, August 2-9. More than 40 papers were delivered by scientists from Belgium, England, France, Germany, Japan, New Zealand, Sweden, Switzerland, Taiwan, the United States, the Soviet Union, Yugoslavia, and other countries. The host country contributed to a productive session that was part of the first large scientific meeting to take place in Beijing after the June 4, 1989, upheaval.Nearly half of the studies focused on paleomagnetic and rock magnetic properties of loess in Alaska, Central Asia, China, and New Zealand. Magnetostratigraphic polarity dating was done at some sections in the western (Shaw et al.) and central Chinese loess plateau (Bai and Hus; Wang and Evans; Yue). The interpretation of the polarity pattern found in the western loess plateau still is not unambiguous. In the central part, certain polarity boundaries, such as the Brunhes/Matuyama (B/M) boundary, are found in slightly different stratigraphic positions (Hus et al.; Yue). In deep-sea sediments the lock-in depth of natural remanent magnetization (NRM) at the B/M boundary seems to be a linear function of sedimentation rate (de Menocal et al.). Although the magnetization process in the Chinese loess is not well understood, detailed records of polarity transitions have been reported for the B/M and the Jaramillo R→N transition (Ma et al.; Rolph).

  16. Mental health outcomes at the Jersey Shore after Hurricane Sandy.

    Science.gov (United States)

    Boscarino, Joseph A; Hoffman, Stuart N; Kirchner, H Lester; Erlich, Porat M; Adams, Richard E; Figley, Charles R; Solhkhah, Ramon

    2013-01-01

    On October 29, 2012, Hurricane Sandy made landfall in the most densely populated region in the US. In New Jersey, thousands of families were made homeless and entire communities were destroyed in the worst disaster in the history of the state. The economic impact of Sandy was huge, comparable to Hurricane Katrina. The areas that sustained the most damage were the small- to medium-sized beach communities along New Jersey's Atlantic coastline. Six months following the hurricane, we conducted a random telephone survey of 200 adults residing in 18 beach communities located in Monmouth County. We found that 14.5% (95% CI = 9.9-20.2) of these residents screened positive for PTSD and 6.0% (95% CI = 3.1-10.2) met criteria for major depression. Altogether 13.5% (95% CI = 9.1-19.0) received mental health counseling and 20.5% (95% CI = 15.1-26.8) sought some type of mental health support in person or online, rates similar to those reported in New York after the World Trade Center disaster In multivariate analyses, the best predictors of mental health status and service use were having high hurricane exposure levels, having physical health limitations, and having environmental health concerns. Research is needed to assess the mental health status and service use of Jersey Shore residents over time, to evaluate environmental health concerns, and to better understand the storm's impact among those with physical health limitations.

  17. Assessment of grass root effects on soil piping in sandy soils using the pinhole test

    Science.gov (United States)

    Bernatek-Jakiel, Anita; Vannoppen, Wouter; Poesen, Jean

    2017-04-01

    Soil piping is a complex land degradation process, which involves the hydraulic removal of soil particles by subsurface flow. This process is frequently underestimated and omitted in most soil erosion studies. However, during the last decades several studies reported the importance of soil piping in various climatic zones and for a wide range of soil types. Compared to sheet, rill and gully erosion, very few studies focused on the factors controlling piping and, so far, there is no research study dealing with the effects of plant roots on piping susceptibility of soils having a low cohesion. The objective of this study is therefore to assess the impact of grass root density (RD) on soil piping in sandy soils using the pinhole test. The pinhole test involves a water flow passing through a hole of 1 mm diameter in a soil specimen (sampled using a metal ring with a diameter of 5 cm and a length of 8 cm), under varying hydraulic heads (50 mm, 180 mm, 380 mm and 1020 mm; Nadal-Romero et al., 2011). To provide a quantitative assessment piping susceptibility of the soil sample, the pipeflow discharge (cm3 s-1) and the sediment discharge (g s-1) were measured every minute during a five minute test. Bare and root-permeated samples were tested, using a sandy soil with a sand, silt, clay content of respectively, 94%, 4% and 2%. The root-permeated topsoil samples were taken in field plots sown with a mixture of grasses with fibrous roots. All soil samples were placed on a sandbox with a 100 mm head for 24 hours to ensure a similar water content for all samples. In total, 67 pinhole tests (lasting 5 minutes each) were conducted, i.e. 43 root-permeated soil samples with RD ranging from 0.01 to 0.93 kg m-3 and 24 root-free soil samples as a reference. Clear piping erosion could be observed in 65% of the root-free soil samples, whereas only 17% of rooted soil samples revealed clear piping erosion during the tests. Statistical analyses show that there is a negative correlation (-0

  18. Morphodynamic Impacts of Hurricane Sandy on the Inner-shelf (Invited)

    Science.gov (United States)

    Trembanis, A. C.; Beaudoin, J. D.; DuVal, C.; Schmidt, V. E.; Mayer, L. A.

    2013-12-01

    Through the careful execution of precision high-resolution acoustic sonar surveys over the period of October 2012 through July 2013, we have obtained a unique set of high-resolution before and after storm measurements of seabed morphology and in situ hydrodynamic conditions (waves and currents) capturing the impact of the storm at an inner continental shelf field site known as the 'Redbird reef' (Raineault et al., 2013). Understanding the signature of this storm event is important for identifying the impacts of such events and for understanding the role that such events have in the transport of sediment and marine debris on the inner continental shelf. In order to understand and characterize the ripple dynamics and scour processes in an energetic, heterogeneous inner-shelf setting, a series of high-resolution geoacoustic surveys were conducted before and after Hurricane Sandy. Our overall goal is to improve our understanding of bedform dynamics and spatio-temporal length scales and defect densities through the application of a recently developed fingerprint algorithm technique (Skarke and Trembanis, 2011). Utilizing high-resolution swath sonar collected by an AUV and from surface vessel multibeam sonar, our study focuses both on bedforms in the vicinity of manmade seabed objects (e.g. shipwrecks and subway cars) and dynamic natural ripples on the inner-shelf in energetic coastal settings with application to critical military operations such as mine countermeasures. Seafloor mapping surveys were conducted both with a ship-mounted multibeam echosounder (200 kHz and 400 kHz) and an Autonomous Underwater Vehicle (AUV) configured with high-resolution side-scan sonar (900 and 1800 kHz) and a phase measuring bathymetric sonar (500 kHz). These geoacoustic surveys were further augmented with data collected by in situ instruments placed on the seabed that recorded measurements of waves and currents at the site before, during, and after the storm. Multibeam echosounder map of

  19. A Coordinated USGS Science Response to Hurricane Sandy

    Science.gov (United States)

    Jones, S.; Buxton, H. T.; Andersen, M.; Dean, T.; Focazio, M. J.; Haines, J.; Hainly, R. A.

    2013-12-01

    In late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection and Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term networks and rapid-deployment real-time streamgages and water-quality monitors tracked river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm-related information from many agencies on the Internet on a daily basis. Immediately following Hurricane Sandy the USGS developed a science plan, 'Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-A U.S. Geological Survey Science Plan for Support of Restoration and Recovery'. The plan will ensure continuing coordination of internal USGS activities as well as

  20. Impact of hillslope vegetation restoration on gully erosion induced sediment yield

    Institute of Scientific and Technical Information of China (English)

    CHEN; Hao; CAI; Qiangguo

    2006-01-01

    Facing the eco-environmental construction on the Loess Plateau, especially the vegetation restoration in the semiarid areas, as well as the dam system engineering construction that is about to start, how can the vegetation restoration gain the optimum ecological benefits following the improvement of the preservation rates of trees and grass on the basis of guaranteeing water storage and silt trapping effects? What techniques should be taken to restore vegetation? These questions critical to environmental management on the Loess Plateau have to be settled urgently. According to the different macroscopic spatial distribution patterns of forest and grass on the Loess Plateau, this paper analyzes the macroscopic hillslope and gully management relationship in the middle Yellow River and weight of natural and human factors in erosion-induced sediment yield in the context of environmental background of the major silt producing areas. In light of the current status of the integrated management of small watersheds and soil and water conservation measure arrangement schemes of hillslopes and gullies on the Loess Plateau, this paper discusses the impact of vegetation restoration on gully erosion induced sediment yield and the effect of vegetation caused sediment reduction. Studies indicate that there exists an erosional environmental background related to the natural and human activities in the sediment yield peak values of the sandy and coarse sandy areas in the middle Yellow River, sediment yield modulus is closely related to the synthetic effect of environmental elements, and the rainstorms, reclamation rate and forest coverage are the main factors affecting sediment yield modulus in the sandy and coarse sandy areas. The key to control soil erosion in the sandy and coarse sandy areas is the conversion of farmland into forestland and grassland, the reduction of reclamation rate and the increase of tree and grass vegetation. Small catchment management should adhere to the

  1. Analyze of waves dynamic over an intertidal mudflat of a sandy-gravely estuarine beach - Field survey and preliminary modeling approach

    Science.gov (United States)

    Morio, Olivier; Sedrati, Mouncef; Goubert, Evelyne

    2014-05-01

    As well as marine submersion or erosive phenomena, clay-silted sediment in-filling on estuarial and bay beaches are a main issue in these human-attractive areas. Coupled sandy/gravely and clay/silty intertidal areas can be observed in these particular coastal areas, depending of rivers characteristic (discharge of particle, water flow), ocean dynamics (wave exposure, current) and sediments sources. All around the world, sandy/gravely beaches are exposed to punctual or continuous input clay sediments. Vilaine estuary, Bay of Arcachon and Bay of Seine in France, Plymouth Bay in UK and also Wadden Sea in Deutschland are few examples of muddy/sandy coupled or mixed system. The beach of Bétahon (Ambon town, Brittany - France) is located on the external Vilaine estuary and is an example of this issue. This meso-macrotidal intermediate (low tide terrace) beach presents heterogeneous sediments. The upper intertidal zone is composed by sand and gravel and characterized by a steep slope. A very gentle slope characterized the lower part of the beach and is constituted by silt and clay. Clay/sand limit is characterized by a decimetric erosion cliff of mudflat along the beach. In order to understand bed variations and sediment transport of this complex heterogeneous beach, a well understanding of wave dynamic across the beach is necessary. This study focus on wave dynamics over the beach, using field observations and MIKE 21 3D wave numerical model. This paper is a preliminary approach of an upcoming global understanding of this estuarial beach behavior. Swell from deep-sea to near-shore area is modeled over a 100 km² area and real wind, deep sea wave characteristic, river water flow and tidal level are defined as open boundary conditions for the regional model. This last one is based on multiple bathymetric surveys over the last 50 years. Local model, triangular mesh gridded to 5 meters, covering Bétahon beach , is based on topographic and photographic survey of the mudflat

  2. Comparison of instream methods for measuring hydraulic conductivity in sandy streambeds.

    Science.gov (United States)

    Landon, M K; Rus, D L; Harvey, F E

    2001-01-01

    Streambed hydraulic conductivity (K) values were determined at seven stream transects in the Platte River Basin in Nebraska using different instream measurement techniques. Values were compared to determine the most appropriate technique(s) for use in sandy streambeds. Values of K determined from field falling- and constant-head permeameter tests analyzed using the Darcy equation decreased as permeameter diameter increased. Seepage meters coupled with hydraulic gradient measurements failed to yield K values in 40% of the trials. Consequently, Darcy permeameter and seepage meter tests were not preferred approaches. In the upper 0.25 m of the streambed, field falling- and constant-head permeameter tests analyzed with the Hvorslev solution generally had similar K values that were significantly greater than those determined using the Hazen grain-size, Bouwer and Rice slug test for anisotropic and isotropic conditions, and Alyamani and Sen grain-size methods; median differences between these tests and the Hvorslev falling-head 60 cm diameter permeameter were about 8, 9, 17, and 35 m/day, respectively. The Hvorslev falling-head permeameter test is considered the most robust method for measuring K of the upper 0.25 m of the streambed because of the inherent limitations of the empirical grain-size methods and less sediment disturbance for permeameter than slug tests. However, lateral variability in K along transects on the Platte, North Platte, and Wood Rivers was greater than variability in K between valid permeameter, grain-size, or slug tests, indicating that the method used may matter less than making enough measurements to characterize spatial variability adequately. At the Platte River tributary sites, the upper 0.3 m of the streambed typically had greater K than sediment located 0.3 to 2.5 m below the streambed surface, indicating that deposits below the streambed may limit ground water/surface water fluxes. The Hvorslev permeameter tests are not a practical

  3. Coastal topography–Northeast Atlantic coast, post-hurricane Sandy, 2012

    Science.gov (United States)

    Stockdon, Hilary F.; Doran, Kara S.; Sopkin, Kristin L.; Smith, Kathryn E.L.; Fredericks, Xan

    2013-01-01

    This Data Series contains lidar-derived bare-earth (BE) topography, dune elevations, and mean-high-water shoreline position datasets for most sandy beaches for Fire Island, New York, and from Cape Henlopen, Delaware to Cape Lookout, North Carolina. The data were acquired post-Hurricane Sandy, which made landfall as an extratropical cyclone on October 29, 2012.

  4. Abrasive wear based predictive maintenance for systems operating in sandy conditions

    NARCIS (Netherlands)

    Woldman, M.; Tinga, T.; Heide, E. van der; Masen, M.A.

    2015-01-01

    Machines operating in sandy environments are damaged by the abrasive action of sand particles that enter the machine and become entrapped between components and contacting surfaces. In the case of the military services the combination of a sandy environment and the wide range of tasks to be fulfille

  5. Heterogeneous water flow and pesticide transport in cultivated sandy soils : description of model concepts

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2011-01-01

    There is ample experimental evidence that complications in water flow and pesticide transport can occur in cultivated humic-sandy and loamy-sandy soils. As a result, pesticide leaching to groundwater and water courses can be higher than expected. We made an inventory of mechanistic/deterministic mod

  6. Measuring Sandy Bottom Dynamics by Exploiting Depth from Stereo Video Sequences

    DEFF Research Database (Denmark)

    Musumeci, Rosaria E.; Farinella, Giovanni M.; Foti, Enrico;

    2013-01-01

    In this paper an imaging system for measuring sandy bottom dynamics is proposed. The system exploits stereo sequences and projected laser beams to build the 3D shape of the sandy bottom during time. The reconstruction is used by experts of the field to perform accurate measurements and analysis i...

  7. Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

    NARCIS (Netherlands)

    Rietkerk, M; Ouedraogo, T; Kumar, L; Sanou, S; van Langevelde, F; Kiema, A; van de Koppel, J; van Andel, J; Hearne, J; Skidmore, AK; de Ridder, N; Stroosnijder, L; Prins, HHT

    We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

  8. Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

    NARCIS (Netherlands)

    Rietkerk, M.G.; Ouedraogo, T.; Kumar, L.; Sanou, S.; Langevelde, F. van; Kiema, A.; Koppel, J. van de; Andel, J. van; Hearne, J.; Skidmore, A.K.; Ridder, N. de; Stroosnijder, L.; Prins, H.H.T.

    2002-01-01

    We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

  9. Nitrate leaching to groundwater at experimental farm "De Marke" and other Dutch sandy soils

    NARCIS (Netherlands)

    Hack-ten Broeke, M.J.D.

    2001-01-01

    This study focuses on nitrate leaching to the groundwater as a result of the land use system of experimental farm 'De Marke', translated to other sandy soils in the Netherlands. The land use was extrapolated to five major sandy soil map units, selected from the 1: 50 000 Soil Map of the Netherlands,

  10. 33 CFR 80.170 - Sandy Hook, NJ to Tom's River, NJ.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sandy Hook, NJ to Tom's River, NJ. 80.170 Section 80.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.170 Sandy Hook, NJ to Tom's River...

  11. Transport and Retention of Toxoplasma gondii Oocysts in Loamy Sand and Sandy Loam Soils

    Science.gov (United States)

    Kinsey, E. N.; Korte, C.; L'Ollivier, C.; Dubey, J. P.; Aurélien, D.; Darnault, C. J. G.

    2016-12-01

    Toxoplasma gondii is one of the most prevalent parasites affecting warm-blooded animals and humans. It has a complex life cycle that involves a wide variety of intermediate hosts with felids as a definitive host. Humans may contract it through consumption of infected, undercooked meat or by water or food sources contaminated with the oocyst form of the parasite. Infection of pregnant women can cause stillbirth, neurological effects or blindness. Because of the prevalence of cats, including on farms where oocyst-contaminated cat feces, animal feed, soil and water have been found, T. gondii is spread almost throughout the entire globe. It has been implicated or suspected in waterborne infections since the 1990s. This study aims to characterize the transport and retention of T. gondii oocysts in field soils. The four soils used were collected from fallow and cultivated fields in Illinois and Utah, USA. They are classified as loamy sands and sandy loams. Soil columns were subjected to continuous artificial rainfall until they reached steady state at which point pulses that included 2.5 million T. gondii oocysts (Me49 strain) and KBr as a tracer were added. After the pulse infiltrated, continuous rainfall was resumed. Rain applied all columns was a 1 mM KCl solution. Leachate samples were collected, analyzed using qPCR for T. gondii and bromide ions and breakthrough curves were produced. Soil was sliced into 1 to 2 cm sections, for which water content and T. gondii concentration were measured to access degree of saturation and oocyst retention.

  12. Depositional dynamics in the El'gygytgyn Crater margin: implications for the 3.6 Ma old sediment archive

    Directory of Open Access Journals (Sweden)

    G. Schwamborn

    2012-11-01

    Full Text Available The combination of permafrost history and dynamics, lake level changes and the tectonical framework is considered to play a crucial role for sediment delivery to El'gygytgyn Crater Lake, NE Russian Arctic. The purpose of this study is to propose a depositional framework based on analyses of the core strata from the lake margin and historical reconstructions from various studies at the site. A sedimentological program has been conducted using frozen core samples from the 141.5 m long El'gygytgyn 5011-3 permafrost well. The drill site is located in sedimentary permafrost west of the lake that partly fills the El'gygytgyn Crater. The total core sequence is interpreted as strata building up a progradational alluvial fan delta. Four macroscopically distinct sedimentary units are identified. Unit 1 (141.5–117.0 m is comprised of ice-cemented, matrix-supported sandy gravel and intercalated sandy layers. Sandy layers represent sediments which rained out as particles in the deeper part of the water column under highly energetic conditions. Unit 2 (117.0–24.25 m is dominated by ice-cemented, matrix-supported sandy gravel with individual gravel layers. Most of the Unit 2 diamicton is understood to result from alluvial wash and subsequent gravitational sliding of coarse-grained (sandy gravel material on the basin slope. Unit 3 (24.25–8.5 m has ice-cemented, matrix-supported sandy gravel that is interrupted by sand beds. These sandy beds are associated with flooding events and represent near-shore sandy shoals. Unit 4 (8.5–0.0 m is ice-cemented, matrix-supported sandy gravel with varying ice content, mostly higher than below. It consists of slope material and creek fill deposits. The uppermost metre is the active layer (i.e. the top layer of soil with seasonal freeze and thaw into which modern soil organic matter has been incorporated. The nature of the progradational sediment transport taking place from the western and northern crater margins may be

  13. The fate of fresh and stored 15N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.

    1996-01-01

    .), or it was applied to ryegrass one month after sowing. In a sandy loam soil, 62% of the incorporated urine N and 78% of the incorporated urea N was recovered in three cuts of herbage after 5 months. In a sandy soil, 51-53% of the labelled N was recovered in the herbage and the distribution of labelled N in plant...... and soil was not significantly different for incorporated urine and urea. Almost all the supplied labelled N was accounted for in soil and herbage in the sandy loam soil, whereas 33-34% of the labelled N was unaccounted for in the sandy soil. When the stored urine was applied to the soil surface, 20...... unaccounted for was probably mainly lost by ammonia volatilization. Significantly more urine- than urea-derived N (36 and 19%, respectively) was immobilized in the sandy loam soil, whereas the immobilization of N from urea and urine was similar in the sandy soil (13-16%). The distribution of urine N, whether...

  14. Seasonal variation of bivalve larvae on an exposed sandy beach on Kashima-nada: Tips for the sandy beach recruitment process

    Science.gov (United States)

    Sawada, Hideki; Saito, Hajime; Adachi, Kumiko; Toyohara, Haruhiko

    2011-02-01

    Bivalves are often the dominant macrobenthos species in exposed sandy beach environments. However, our understanding of their recruitment processes before post-settlement stages on sandy beaches with highly energetic environments is incomplete. To clarify the characteristics of the free-swimming planktonic stage that affects recruitment efficiency in sandy shore ecosystems, we investigated the temporal (weekly-biweekly) variation of bivalve planktonic larval concentration coupled with oceanographic conditions on an exposed sandy shore on the sea of Kashima-nada, Japan, from summer 2003 to autumn 2005. Larvae were observed throughout the year, but the surge of larval concentration composed of sandy beach and sessile bivalves occurred most prominently in summer, from August to September. The peak concentration of larvae during this season was more than 1000 times higher than in other seasons. The larval concentration was positively correlated with water temperature and northward wind velocity and negatively correlated with each of the nutrient concentrations. On the other hand, chlorophyll a concentration and salinity seemed to have little effect on the larval concentration. Based on this fundamental knowledge, further investigations about planktonic larvae in sandy beaches are needed.

  15. Effect of sediment properties on the sorption of C{sub 12}-2-LAS in marine and estuarine sediments

    Energy Technology Data Exchange (ETDEWEB)

    Rico-Rico, Angeles [Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3508 TD Utrecht (Netherlands)], E-mail: a.ricorico@uu.nl; Temara, Ali [Procter and Gamble Company, Central Product Safety, Temselaan 100, 1853 Strombeek-Bever (Belgium); Behrends, Thilo [Department of Earth Sciences-Geochemistry, Faculty of Geosciences, Utrecht University, 3508 TA Utrecht (Netherlands); Hermens, Joop L.M. [Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3508 TD Utrecht (Netherlands)

    2009-02-15

    Linear alkylbenzene sulfonates (LAS) are anionic high production volume surfactants used in the manufacture of cleaning products. Here, we have studied the effect of the characteristics of marine and estuarine sediments on the sorption of LAS. Sorption experiments were performed with single sediment materials (pure clays and sea sand), with sediments treated to reduce their organic carbon content, and with field marine and estuarine sediments. C{sub 12}-2-LAS was used as a model compound. Sorption to the clays montmorillonite and kaolinite resulted in non-linear isotherms very similar for both clays. When reducing the organic content, sorption coefficients decreased proportionally to the fraction removed in fine grain sediments but this was not the case for the sandy sediment. The correlation of the sediment characteristics with the sorption coefficients at different surfactant concentrations showed that at concentrations below 10 {mu}g C{sub 12}-2-LAS/L, the clay content correlated better with sorption, while the organic fraction became more significant at higher concentrations. - Sorption of C{sub 12}-2-LAS to marine sediments mainly depends on both clay and organic carbon content. The importance of each parameter varies with the surfactant concentration.

  16. Retention and degradation of the cyanobacterial toxin cylindrospermopsin in sediments - the role of sediment preconditioning and DOM composition.

    Science.gov (United States)

    Klitzke, Sondra; Apelt, Susann; Weiler, Christiane; Fastner, Jutta; Chorus, Ingrid

    2010-05-01

    Recent results show that cylindrospermopsin is more frequent and widespread in surface waters than previously assumed. Studies on the fate of CYN in sediments are lacking, but this is important if these resources are used for drinking-water production via sediment passage. Therefore, the aim of our study was to determine a) CYN retention in two sandy sediments as a function of flow rate, CYN concentration, the presence of DOM and the content of fines (1% and 4%, respectively) and b) the influence of sediment preconditioning and DOM composition of the water (aquatic DOM versus DOM released from lysed cells) on CYN degradation. Retention of CYN proved negligible under the investigated conditions. Degradation in virgin sediments showed the highest lag phases (20 days). Preconditioned sediments showed no lag phase. The presence of aquatic DOM yielded highest degradation rates (kappa(1)=0.46 and 0.49 day(-1)) without a lag phase. Readily available organic carbon sources were preferentially metabolized and hence induced a lag phase. Thus, the presence and composition of DOM in the water proved important for both CYN degradation rates in preconditioned sediments and for the lag phase. Cylindrospermopsin degradation took place solely in the sediment and not in the water body. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar point-cloud data (LAS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  18. Progress in sandy desertification research of China%中国沙漠化研究进展

    Institute of Scientific and Technical Information of China (English)

    王涛

    2004-01-01

    Sandy desertification is land degradation characterized by wind erosion mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in northern China. The research on sandy desertification has experienced more than 5 decades of arduous course of the struggle along with the establishment and development of China′s desert science. Researches in this field have made a great contribution to the national economic construction, and environmental protection. This paper focuses on presenting the major progress and achievements in the sandy desertification research during the last 50 years, including the stages of study on sandy desertification,background environment of sandy desertification and its changes, the conception, causes, process,monitoring and assessment of sandy desertification, the vegetation succession, landscape ecology, plant physiology, impacts on ecosystem, high-effective use of water and land resources and sustainable development in sandy desertified regions, sandy desertification control models and techniques etc.

  19. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar point-cloud data (LAS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  20. Hurricane Sandy: Shared Trauma and Therapist Self-Disclosure.

    Science.gov (United States)

    Rao, Nyapati; Mehra, Ashwin

    2015-01-01

    Hurricane Sandy was one of the most devastating storms to hit the United States in history. The impact of the hurricane included power outages, flooding in the New York City subway system and East River tunnels, disrupted communications, acute shortages of gasoline and food, and a death toll of 113 people. In addition, thousands of residences and businesses in New Jersey and New York were destroyed. This article chronicles the first author's personal and professional experiences as a survivor of the hurricane, more specifically in the dual roles of provider and trauma victim, involving informed self-disclosure with a patient who was also a victim of the hurricane. The general analytic framework of therapy is evaluated in the context of the shared trauma faced by patient and provider alike in the face of the hurricane, leading to important implications for future work on resilience and recovery for both the therapist and patient.

  1. Performance of social network sensors during Hurricane Sandy.

    Directory of Open Access Journals (Sweden)

    Yury Kryvasheyeu

    Full Text Available Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow and derive early-warning sensors, thus improving emergency preparedness and response. Performance of the social networks sensor method, based on topological and behavioral properties derived from the "friendship paradox", is studied here for over 50 million Twitter messages posted before, during, and after Hurricane Sandy. We find that differences in users' network centrality effectively translate into moderate awareness advantage (up to 26 hours; and that geo-location of users within or outside of the hurricane-affected area plays a significant role in determining the scale of such an advantage. Emotional response appears to be universal regardless of the position in the network topology, and displays characteristic, easily detectable patterns, opening a possibility to implement a simple "sentiment sensing" technique that can detect and locate disasters.

  2. Performance of social network sensors during Hurricane Sandy.

    Science.gov (United States)

    Kryvasheyeu, Yury; Chen, Haohui; Moro, Esteban; Van Hentenryck, Pascal; Cebrian, Manuel

    2015-01-01

    Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow and derive early-warning sensors, thus improving emergency preparedness and response. Performance of the social networks sensor method, based on topological and behavioral properties derived from the "friendship paradox", is studied here for over 50 million Twitter messages posted before, during, and after Hurricane Sandy. We find that differences in users' network centrality effectively translate into moderate awareness advantage (up to 26 hours); and that geo-location of users within or outside of the hurricane-affected area plays a significant role in determining the scale of such an advantage. Emotional response appears to be universal regardless of the position in the network topology, and displays characteristic, easily detectable patterns, opening a possibility to implement a simple "sentiment sensing" technique that can detect and locate disasters.

  3. Public support for policies to reduce risk after Hurricane Sandy.

    Science.gov (United States)

    Greenberg, Michael R; Weiner, Marc D; Noland, Robert; Herb, Jeanne; Kaplan, Marjorie; Broccoli, Anthony J

    2014-06-01

    A phone survey was conducted in New Jersey in 2013 four months after the second of two major devastating tropical storms (Sandy in 2012 and Irene in 2011). The objective was to estimate public support for restricting land uses in flood zones, requiring housing to be built to resist storm waters, and otherwise increasing mitigation and resilience. Respondents who supported these mitigation and resilience policies disproportionately were concerned about global climate change, trusted climate scientists and the federal government, and were willing to contribute to a redevelopment program through taxes, bonds, and fees. They also tended to have collectivist and egalitarian worldviews. Half of the respondents supported at least four of the seven risk-reducing policies. How their support translates into public policy remains to be seen. Lack of willingness to personally fund these policies is an obstacle.

  4. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Boddum, J. K.

    2000-01-01

    ; Zn: 6±22,800 l/kg) and correlating them to the characteristics of the aquifer material (particle size distribution, organic C content, surface area, pH) revealed good correlation with pH in the range 5.3± 8.9 (Cu: r 2=0.72; Zn: r 2=0.94). Including any other of the measured aquifer characteristics...... improved the correlation only a few percent. The results indicate that the mobility of Cu and Zn in sandy aquifers, as re¯ected in the measured Kd values, is very restricted at pH values above 6, since the relative migration velocity is less than 1%. However, at lower pH values, Zn seems to become mobile...

  5. Remediation of sandy soils using surfactant solutions and foams.

    Science.gov (United States)

    Couto, Hudson J B; Massarani, Guilio; Biscaia, Evaristo C; Sant'Anna, Geraldo L

    2009-05-30

    Remediation of sandy soils contaminated with diesel oil was investigated in bench-scale experiments. Surfactant solution, regular foams and colloidal gas aphrons were used as remediation fluids. An experimental design technique was used to investigate the effect of relevant process variables on remediation efficiency. Soils prepared with different average particle sizes (0.04-0.12 cm) and contaminated with different diesel oil contents (40-80 g/kg) were used in experiments conducted with remediation fluids. A mathematical model was proposed allowing for the determination of oil removal rate-constant (k(v)) and oil content remaining in the soil after remediation (C(of)) as well as estimation of the percentage of oil removed. Oil removal efficiencies obtained under the central experimental design conditions were 96%, 88% and 35% for aphrons, regular foams and surfactant solutions, respectively. High removal efficiencies were obtained using regular foams and aphrons, demanding small amounts of surfactant.

  6. Visual Odometry for Planetary Exploration Rovers in Sandy Terrains

    Directory of Open Access Journals (Sweden)

    Linhui Li

    2013-05-01

    Full Text Available Visual odometry provides planetary exploration rovers with accurate knowledge of their position and orientation, which needs effective feature tracking results, especially in barren sandy terrains. In this paper, a stereovision based odometry algorithm is proposed for a lunar rover, which is composed of corner extraction, feature tracking and motion estimation. First, a morphology based image enhancement method is studied to guarantee enough corners are extracted. Second, a Random Sample Consensus (RANSAC algorithm is proposed to make a robust estimation of the fundamental matrix, which is the basic and critical part of feature matching and tracking. Then, the 6 degrees of freedom rover position and orientation is estimated by the RANSAC algorithm. Finally, experiments are performed in a simulated lunar surface environment using a prototype rover, which have confirmed the feasibility and effectiveness of the proposed method.

  7. Performance of Social Network Sensors during Hurricane Sandy

    Science.gov (United States)

    Kryvasheyeu, Yury; Chen, Haohui; Moro, Esteban; Van Hentenryck, Pascal; Cebrian, Manuel

    2015-01-01

    Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow and derive early-warning sensors, thus improving emergency preparedness and response. Performance of the social networks sensor method, based on topological and behavioral properties derived from the “friendship paradox”, is studied here for over 50 million Twitter messages posted before, during, and after Hurricane Sandy. We find that differences in users’ network centrality effectively translate into moderate awareness advantage (up to 26 hours); and that geo-location of users within or outside of the hurricane-affected area plays a significant role in determining the scale of such an advantage. Emotional response appears to be universal regardless of the position in the network topology, and displays characteristic, easily detectable patterns, opening a possibility to implement a simple “sentiment sensing” technique that can detect and locate disasters. PMID:25692690

  8. Nematode Faunal Response to Grassland Degradation in Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The responses of soil nematode communities to grassland degradation were studied under undegraded grassland (UG),degraded grassland (DG), and improved grassland (IG), in Horqin Sandy Land, Inner Mongolia, Northeast China. Soil samples were collected at depths of 0-10, 10-20, and 20-30 cm. Total organic carbon (TOC) and total nitrogen (TN)exhibited positive effects on the total number of nematodes and trophic groups. Significant treatment effects were found in the total number of nematodes, plant parasites, and omnivores-predators. Measures taken in the improved grassland could improve the number of omnivore-predators, especially in the deeper soil layers. Nematode richness was lower in the DG treatment than in the IG and UG treatments. The food web structure index (SI) was significantly higher in the UG and IG treatments than in the DG treatment. A higher SI suggested a food web with more trophic linkages and relatively healthy ecosystems.

  9. Extraction Efficiency of Belonolaimus longicaudatus from Sandy Soil.

    Science.gov (United States)

    McSorley, R; Frederick, J J

    1991-10-01

    Numbers of Belonolaimus longicaudatus extracted from sandy soils (91-92% sand) by sieving and centrifugation were only 40-55% of those extracted by sieving and incubation on a Baermann tray. Residues normally discarded at each step of the sieving plus Baermann tray extraction procedure were examined for nematodes to obtain estimates of extraction efficiencies. For third-stage and fourth-stage juveniles, males, and females, estimates of extraction efficiency ranged from 60 to 65% in one experiment and 73 to 82% in another. Estimated extraction efficiencies for second-stage juveniles were lower (33% in one experiment, 67% in another) due to losses during sieving. When sterilized soil was seeded with known numbers of B. longicaudatus, 60% of second-stage juveniles and 68-76% of other stages were recovered. Most stages of B. longicaudatus could be extracted from these soils by sieving plus Baermann incubation with an efficiency of 60-70%.

  10. 78 FR 52560 - Hurricane Sandy Rebuilding Task Force-Rebuild-by-Design; Announcement of Selection of Design Teams

    Science.gov (United States)

    2013-08-23

    ... URBAN DEVELOPMENT Hurricane Sandy Rebuilding Task Force--Rebuild-by-Design; Announcement of Selection of Design Teams AGENCY: Hurricane Sandy Task Force, HUD. ACTION: Notice. SUMMARY: In June 2013, the Hurricane Sandy Task Force launched Rebuild by Design, a multi-stage regional design competition to...

  11. Quantifying human mobility perturbation and resilience in Hurricane Sandy.

    Science.gov (United States)

    Wang, Qi; Taylor, John E

    2014-01-01

    Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.

  12. Mitigation of Liquefaction in Sandy Soils Using Stone Columns

    Science.gov (United States)

    Selcuk, Levent; Kayabalı, Kamil

    2010-05-01

    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  13. Quantifying human mobility perturbation and resilience in Hurricane Sandy.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.

  14. Effect of morphodynamics on annual average zonation pattern of benthic macrofauna of exposed sandy beaches in Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Eliana dos Santos Alves

    2009-09-01

    Full Text Available This study investigated the effect of environmental factors on the annual average zonation pattern of benthic macrofauna of sub-aerial profile of three exposed sandy beaches of Santa Catarina with different morphodynamic characteristics. Sampling was carried out between March 2000 and March 2001, with monthly frequency on reflective and dissipative morphodynamic extremes and bimonthly frequency on the intermediate state. Results showed that macrobenthic zonation presented marked differences across the morphodynamic spectrum. The main differences observed from reflective to dissipative conditions were: a increase in the number of species in lower zones of the beach; b expansion of zones characterized by high water content of sediment and c increase in the overlapping of zones, mainly on lower levels of the beach. Canonical Correspondence Analysis related these differences to distinctive cross-shore gradients in sediment moisture levels, sediment reworking and mean grain size that exist across the morphodynamic spectrum, showing that it is important to analyze these environmental factors in studies conducted to investigate zonation on microtidal exposed sandy beaches.Este estudo analisou o efeito dos fatores ambientais sobre a zonação da macrofauna bentônica da porção subaérea de praias arenosas expostas e caracterizadas por diferentes estágios morfodinâmicos em Santa Catarina. As amostragens foram realizadas entre março/2000 e março/2001, a intervalos mensais nos extremos morfodinâmicos e bimestrais no estágio intermediário. Os resultados obtidos demonstraram que a zonação da macrofauna bentônica apresentou as seguintes diferenças, do extremo refletivo para o dissipativo: a aumento do número de espécies nos níveis inferiores da praia; b aumento da extensão das zonas faunísticas caracterizadas por elevado teor de umidade do sedimento; e c aumento da sobreposição das zonas faunísticas, principalmente, nos níveis inferiores

  15. Turning the tide: effects of river inflow and tidal amplitude on sandy estuaries in laboratory landscape experiments

    Science.gov (United States)

    Kleinhans, Maarten; Braat, Lisanne; Leuven, Jasper; Baar, Anne; van der Vegt, Maarten; van Maarseveen, Marcel; Markies, Henk; Roosendaal, Chris; van Eijk, Arjan

    2016-04-01

    Many estuaries formed over the Holocene through a combination of fluvial and coastal influxes, but how estuary planform shape and size depend on tides, wave climate and river influxes remains unclear. Here we use a novel tidal flume setup of 20 m length by 3 m width, the Metronome (http://www.uu.nl/metronome), to create estuaries and explore a parameter space for the simple initial condition of a straight river in sandy substrate. Tidal currents capable of transporting sediment in both the ebb and flood phase because they are caused by periodic tilting of the flume rather than the classic method of water level fluctuation. Particle imaging velocimetry and a 1D shallow flow model demonstrate that this principle leads to similar sediment mobility as in nature. Ten landscape experiments recorded by timelapse overhead imaging and AGIsoft DEMs of the final bed elevation show that absence of river inflow leads to short tidal basins whereas even a minor discharge leads to long convergent estuaries. Estuary width and length as well as morphological time scale over thousands of tidal cycles strongly depend on tidal current amplitude. Paddle-generated waves subdue the ebb delta causing stronger tidal currents in the basin. Bar length-width ratios in estuaries are slightly larger to those in braided rivers in experiments and nature. Mutually evasive ebb- and flood-dominated channels are ubiquitous and appear to be formed by an instability mechanism with growing bar and bifurcation asymmetry. Future experiments will include mud flats and live vegetation.

  16. Sulfur and oxygen isotopic study of Paleozoic sediment-hosted Zn-Pb(-Ag-Au-Ba-F) deposits and associated hydrothermal alteration zones in the Nome Complex, Seward Peninsula, Alaska

    Science.gov (United States)

    Shanks, W.C. Pat; Slack, John F.; Till, Alison B.; Thurston, Roland; Gemery-Hill, Pamela

    2014-01-01

    Results of sulfur and oxygen isotope studies of sedimentary exhalative (SEDEX) Zn-Pb(-Ag-Au-Ba-F) deposits hosted in metamorphosed Paleozoic clastic and carbonate rocks of the Nome Complex, Seward Peninsula, Alaska, are consistent with data for similar deposits worldwide. Stable isotopic studies of the Nome Complex are challenging because the rocks have undergone Mesozoic blueschist- and greenschist-facies metamorphism and deformation at temperatures estimated from 390–490 °C. Studies of sulfur and oxygen isotopes in other areas suggest that, in the absence of chemical and mineralogical evidence for metasomatism, the principal effect of metamorphism is re-equilibration between individual minerals at the temperature of metamorphism, which commonly leads to a narrowing of the overall range of isotope values for a suite of rocks, but generally does not significantly modify the average whole rock value for that suite. Sulfur isotope studies of the stratabound and locally stratiform sulfide lenses at the Aurora Creek-Christophosen deposit, which is of possible Late Devonian-early Carboniferous age, show a large range of δ34Ssulfide values from -9.7 to 39.4‰, suggesting multiple sulfur sources and possibly complex processes of sulfide formation that may include bacterial sulfate reduction, thermochemical sulfate reduction, and Rayleigh distillation. Low δ34S values probably represent bacterial sulfide minerals remobilized from the host metasedimentary rocks either during the original seafloor mineralization or are related to a Cretaceous mineralizing event that produced Au-vein and base-metal replacement deposits; the latter process is supported by Pb isotope data. The Wheeler North deposit is similar to Aurora Creek-Christophosen but does not have negative δ34S values. It also probably formed in an euxinic sub-basin.

  17. Assessment of sandy desertification trends in the Shule River Basin from 1978 to 2010

    Institute of Scientific and Technical Information of China (English)

    Xiang Song; ChangZhen Yan; Sen Li; JiaLi Xie

    2014-01-01

    Sandy desertification in the Shule River Basin has expanded dramatically during the past 30 years. We evaluated the status, evolution, and main causes of sandy desertification by interpreting Landsat images which were acquired in 1978, 1990, 2000, 2005, and 2010, and analyzing the relevant meteorological data. The results show there was 3,477.95 km2, 3,733.32 km2, 3,620.29 km2, 3,565.65 km2, and 3,557.88 km2 of sandy desertified land in 1978, 1990, 2000, 2005, and 2010, respectively. From 1978 to 1990, not only the area of sandy desertified land (SDL) but also the degree of SDL levels increased. From 1990 to 2010 there was widespread restoration of SDL but the recovery trend of SDL gradually slowed. Although climate change contributes to expanding sandy desertification, human activities can either accelerate or reverse trends of natural sandy desertification. Some detrimental human activities can accelerate sandy desertification, but, conversely, desertification control measures such as the Three-North Shelter Forest Project and watershed rehabilitation programs in areas including the Shule River Basin resulted in many SDL being turned into grasslands or forest lands when shrubs and trees were planted to fix mobile sands at the edges of oases and cities. With population growth, much SDL has been reclaimed as farm land using water-saving agricultural methods or has been turned into built-up land as a result of urbanization.

  18. Field investigation of surface sand and dust movement over different sandy grasslands in the Otindag Sandy Land, China

    Science.gov (United States)

    Liu, Shulin; Wang, Tao; Chen, Guangting; Guo, Jian; Xue, Xian; Ma, Shaoxiu

    2008-01-01

    The characteristics of sand and dust movement over different sandy grasslands in China’s Otindag Sandy Land were explored based on field observations and laboratory analyses. Threshold wind speeds (the speed required to initiate sand movement) at a height of 2 m above the ground were estimated in the field for different surface types. Threshold wind speed above shifting dunes in the study area is about 4.6 m s-1 at this height. This value was smaller than values observed above other surfaces, resulting in a greater risk of blowing sand above these dunes. Differences in sand transport rates (STR) as a function of the severity of desertification resulted primarily from differences in surface vegetation cover and secondarily from the soil’s grain-size distribution. STR increased exponentially with increasing near-bed wind velocity. Under the same wind conditions, STR increased with increasing severity of desertification: from 0.08 g cm-2 min-1 above semi-fixed dunes to 8 g cm-2 min-1 above semi-shifting dunes and 25 g cm-2 min-1 above shifting dunes. Vegetation’s affect on STR was clearly large. Different components of sand and dust were trapped over different lands: mostly sand grains but little dust were trapped above shifting dunes, but much dust was collected over semi-shifting and semi-fixed dunes. Human disturbance is likely to produce dust even from fixed dunes as a result of trampling by animals and vehicle travel. In addition, spring rainfall decreased the risk of sand and dust movement by accelerating germination of plants and the formation of a soil crust.

  19. Quantifying the process-product relationship in the large sandy Rio Paraná

    Science.gov (United States)

    Ashworth, P. J.; Amsler, M.; Best, J.; Orfeo, O.; Parsons, D.; Reesink, A.; Sambrook Smith, G.; Szupiany, R.

    2010-12-01

    Whilst recent technological advances have enabled the measurement and modelling of alluvial processes and dynamics, arguably less progress has been made in relating the morphodynamics to the resulting sedimentary alluvial architecture. This paper will present data from the sandy, multi-channel Rio Paraná, Argentina, where the evolution of km-scale braid-bars is being related directly to the resultant sedimentary deposits. Bathymetric data from the Rio Paraná was collected from survey vessels using single and multi-beam echo-sounding located by RTK dGPS. Flow data at various flow stages was also collected using acoustic Doppler current profiler (aDcp) surveys at key cross-sections. The subsurface architecture was characterised at low flow using 10s of km of Ground Penetrating Radar (GPR), and ground-truthed using suction coring. GPR achieved penetration depths down to 10 m and reflections allowed quantification of the radar facies to within +/- 0.2 m in the vertical. These techniques, and the logistical considerations required in their deployment and integration in the field, will be discussed. The paper will also highlight how an integrated morphodynamic and GPR survey programme in one of the world’s largest rivers can provide high-resolution data that: (i) links blocks of sedimentation to specific, identifiable channel processes, (ii) quantifies the vertical and horizontal distribution of sedimentary facies in large rivers, and relates this to the temporal evolution of the channel, and (iii) is at sub-seismic resolution and therefore suitable for reservoir-scale lithofacies modelling.

  20. Quantifying microplastic pollution on sandy beaches: the conundrum of large sample variability and spatial heterogeneity.

    Science.gov (United States)

    Fisner, Mara; Majer, Alessandra P; Balthazar-Silva, Danilo; Gorman, Daniel; Turra, Alexander

    2017-05-01

    Despite the environmental risks posed by microplastic pollution, there are presently few standardized protocols for monitoring these materials within marine and coastal habitats. We provide a robust comparison of methods for sampling microplastics on sandy beaches using pellets as a model and attempt to define a framework for reliable standing stock estimation. We performed multiple comparisons to determine: (1) the optimal size of sampling equipment, (2) the depth to which samples should be obtained, (3) the optimal sample resolution for cross-shore transects, and (4) the number of transects required to yield reproducible along-shore estimates across the entire sections of a beach. Results affirmed that the use of a manual auger with a 20-cm diameter yielded the best compromise between reproducibility (i.e., standard deviation) and sampling/processing time. Secondly, we suggest that sediments should be profiled to a depth of at least 1 m to fully assess the depth distribution of pellets. Thirdly, although sample resolution did not have major consequence for overall density estimates, using 7-m intervals provides an optimal balance between precision (SD) and effort (total sampling time). Finally, and perhaps most importantly, comparing the minimum detectable difference yielded by different numbers of transects along a given section of beach suggests that estimating absolute particle density is probably unviable for most systems and that monitoring might be better accomplished through hierarchical or time series sampling efforts. Overall, while our study provides practical information that can improve sampling efforts, the heterogeneous nature of microplastic pollution poses a major conundrum to reproducible monitoring and management of this significant and growing problem.

  1. Carbon and nitrogen stoichiometry regulates the magnitude and temporal dynamics of nitrogenous nutrient regeneration in sandy beach pore water

    Science.gov (United States)

    Goodridge, B. M.; Melack, J. M.

    2013-12-01

    Sandy beaches are located at the interface of terrestrial and marine ecosystems, lining about 70% of the world's ice-free coastline. They can be conduits for fresh groundwater delivery of dissolved inorganic nitrogen (DIN), a vital and often limiting nutrient source, to oceans along coastlines where a hydrologic connection exists with shallow coastal aquifers. However, even along such coastlines, the majority of water within beach sands is recirculated seawater (i.e., pore water), and the regeneration of DIN from the mineralization of marine organic matter (OM) is considered the dominant source of DIN in beach pore water and flux to coastal oceans. The biogeochemical mechanisms regulating the magnitude of and temporal changes in DIN regeneration in saline beach pore water are therefore of prime importance in assessing the role of beaches in coastal marine nitrogen cycling. We assessed the potential stoichiometric control of resource carbon to nitrogen (C:N) on pore water DIN regeneration at four sandy beach study locations, and temporal evolution of pore water C:N at two of the four study locations, along the Santa Barbara, California coastline during synoptic sampling events over the course of a year. We identified pore water dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) as the resources most likely available to microbial heterotrophic metabolism (i.e., C:N), the dominant catalyst of DIN regeneration in marine sediments, finding a negative exponential correlation of DIN with DOC:TDN ratios (673 × 173 e-1.05 × 0.30(DOC:TDN); R2 = 0.55, n = 123). DOC:TDN ratios also demonstrated a negative exponential correlation with residence time (10.0 × 1.7 e-1.08 × 0.48(RT) + 1.61 × 0.54; R2 = 0.79, n = 46), estimated using radon-222 as a pore water residence time tracer. Using model-derived DOC:TDN ratios as the independent variable in the DIN vs. DOC:TDN relationship, we explored temporal changes in DIN regeneration. The modeled DIN vs. residence time

  2. Soil erosion rates by wind-driven rain from a sandy soil in Denmark

    Science.gov (United States)

    Fister, W.; Kuhn, N. J.; Itin, N.; Tesch, S.; Heckrath, G.; Ries, J. B.

    2012-04-01

    Soil erosion by wind and water is able to cause severe soil loss from agricultural fields. Laboratory studies in recent years have shown that wind most probably has an increasing effect on soil erosion rates by water. However, field studies have so far not been able to quantify and proof this assumption explicitly. Especially the differentiation between the influence of windless and wind-driven erosion seems to be the major issue. The objectives of this study were, therefore, to explicitly investigate the importance of wind-driven rain in relation to erosion rates without the effect of wind by applying a newly developed Portable Wind and Rainfall Simulator (PWRS) that is able to simulate the processes both separately and simultaneously. The PWRS was used on bare sandy soil near Viborg, Denmark. Prior to simulation the soil was ploughed and after consolidation harrowed to create surface structures and roughness representing typical conditions after seed bed preparation. To facilitate the separation of specific influences by wind-driven rain and to avoid systematic errors a defined order of four consecutive test runs was established: 0) single wind test run for 10 min, 1) single rainfall test run on dry soil, 2) single rainfall test run on moist soil, 3) simultaneous wind and rainfall test run (wind-driven rainfall). Each rainfall simulation lasted for 30 minutes with a 30 min break in between to allow for initial drainage of the soil and for remounting sediment catchers. By utilizing a gutter in combination with wedge-shaped sediment traps it was possible to separate between splash and runoff erosion from the 2.2 m2 plot. The results show a wide range of soil detachment raging from zero up to more than 500 g m-2 in 30 minutes. Five out of nine test sequences support the theory that wind-driven rain causes more erosion than windless rain. The relation between the two processes is therefore not as clear as expected and seems to be dominated by the natural variability

  3. Geoacoustic model of surface sediments in the southwestern Ulleung basin, the East Sea of Korea

    Science.gov (United States)

    Kim, S. H.; Kim, D. C.; Lee, G. S.; Kim, S. P.; Bae, S. H.

    2012-04-01

    To realization of geoacoustic model in the southwestern Ulleung basin, the East Sea of Korea, eighty-two piston core samples and sixty-six box core samples were collected. Sediment texture (mean grain size and sand, silt, and clay contents), physical properties (porosity, water content, bulk density, and grain density), and acoustic properties (compressional wave velocity and attenuation) were measured using surface sediments below 40 cm from the surface. As the results, the study area is divided into five sub-areas based on acoustic property of sediments: (1) Area I is composed of muddy sediments that affected directly by the Nakdong River discharge. The velocity is almost 1490 m/s. (2) Area II is generally characterized by hemi-pelagic muds and partially mixed with intermittent sandy sediments originated from the outer shelf and upper slope. The velocity approximately ranges from 1490 to 1500 m/s. (3) Area III is comprised of muddy sand sediments that are corresponds to the boundary between recent sediments and relict sediments. The velocity ranges from 1500 to 1600 m/s. (4) Area IV is dominated by coarse-grained relict sediments. The velocity ranges from 1600 to 1700 m/s. And (5) Area V consists of very coarser sediments. The velocity is higher than 1700 m/s. The sediment velocity generally decreases with increasing porosity or decreasing mean grain size and bulk density.

  4. Salt wedge dynamics lead to enhanced sediment trapping within side embayments in high-energy estuaries

    Science.gov (United States)

    Yellen, Brian; Woodruff, Jonathan D.; Ralston, David K.; MacDonald, D. G.; Jones, D. S.

    2017-03-01

    Off-river coves and embayments provide accommodation space for sediment accumulation, particularly for sandy estuaries where high energy in the main channel prevents significant long-term storage of fine-grained material. Seasonal sediment inputs to Hamburg Cove in the Connecticut River estuary (USA) were monitored to understand the timing and mechanisms for sediment storage there. Unlike in freshwater tidal coves, sediment was primarily trapped here during periods of low discharge, when the salinity intrusion extended upriver to the cove entrance. During periods of low discharge and high sediment accumulation, deposited sediment displayed geochemical signatures consistent with a marine source. Numerical simulations reveal that low discharge conditions provide several important characteristics that maximize sediment trapping. First, these conditions allow the estuarine turbidity maximum (ETM) to be located in the vicinity of the cove entrance, which increases sediment concentrations during flood tide. Second, the saltier water in the main channel can enter the cove as a density current, enhancing near-bed velocities and resuspending sediment, providing an efficient delivery mechanism. Finally, higher salinity water accumulates in the deep basin of the cove, creating a stratified region that becomes decoupled from ebb currents, promoting retention of sediment in the cove. This process of estuarine-enhanced sediment accumulation in off-river coves will likely extend upriver during future sea level rise.

  5. Seasonal variability in free-living marine nematode community structure in a sandy beach of the Taiping Bay of Qingdao, China

    Institute of Scientific and Technical Information of China (English)

    LIU Haibin; ZHANG Zhinan; FAN Shiliang; HUA Er; DENG Ke

    2008-01-01

    Nematode assemblage composition,trophic structure and biodiversity were followed over an annual cycle in a sandy beach of the Taiping Bay of Qingdao,China.Nematode assemblage in the sandy beach maintained a high genus diversity (75 genera).Micro-laimus and Bathylaimus were the dominant genus of the nematode assemblage,accounting for 66% of the total nematode abun-dance.The nematodes' dominant trophic structure changed seasonally as a response to the seasonal changes in food quality.Epi-growth-feeder nematodes (2A) were the dominant trophic groups in the trophic structure with the highest abundance in spring be-cause of phytoplankton bloom,while the feeding type (1B) showed higher abundance in summer that was due to the increasing of sediment detritus after spring bloom.Furthermore,species diversity and evenness calculated on nematodes identified to the genus level displayed significant temporal changes,which was also reflected by the index of trophic diversity.According to the cluster analysis,the nematode community structure of the whole year was clearly separated into two periods ( A and B).Biota-Environ-ment matching (BIOENV) results showed that seawater temperature,sediment Chl a and grain size were responsible for the nema-tode community structure variation in spring and summer period (Period A).However,seawater/interstitial water temperature,interstitial water dissolved oxygen concentration,interstitial water salinity,and sediment Ph a a were more important in construc-ting the autumn and winter period ( Period B) nematode community structure.

  6. Content Analysis of Select YouTube Postings: Comparisons of Reactions to the Sandy Hook and Aurora Shootings and Hurricane Sandy.

    Science.gov (United States)

    Miller, Eric D

    2015-11-01

    This study details an innovative and methodical content analysis of 2,207 YouTube comments from four different YouTube videos (e.g., breaking news or memorials) related to the 2012 Sandy Hook Elementary School and Aurora theater mass shootings and the catastrophic Hurricane Sandy. As expected, YouTube comments associated with the Sandy Hook shootings (particularly those from a memorial video) were especially likely to feature compassion and grief with lessened hostility. This study highlights differing online contexts by which individuals show grief and related emotions following man-made and natural calamities and how-even in an online environment-powerful situational contexts greatly guide behavior.

  7. Characterization of Tunisian marine sediments in Rades and Gabes harbors

    Institute of Scientific and Technical Information of China (English)

    Imen BEL HADJ ALI; Zoubeir LAFHAJ; Mounir BOUASSIDA; Imen SAID

    2014-01-01

    The objective of this article is to study the geotechnical and environmental characteristics of sediments dredged from two Tunisian harbors:Rades and Gabes. The first harbor represents the main facility place in the national transport chain. The second one is selected as its sediments present a serious ecological constraint caused by the discharge of wastes into the marine environment. These sediments are either discarded at sea or landfilled despite their harmful effects on the environment. The article is divided into three main sections. The first one presents the material that was carried for Rades and Gabes harbors. The conservation conditions and the used experimental tests are detailed. Geotechnical characterization includes the determination of the grain size distribution, the water content, the Atterberg limits, the methylene blue value, the specific area, the bulk density, the specific unit weight, the organic and carbonate contents. Environmental characterization is assessed by the determination of metals concentrations in a leaching solution. The second section deals with the description and analysis of geotechnical properties of Rades and Gabes harbors’ sediments. The results obtained show that Rades harbor sediments are slightly sandy clayey silts whereas Gabes harbor sediments are silty sands characterized by a highly plastic clay fraction. Both of the two sediments don’t exhibit a high organic content. Finally, chemical, mineralogical and environmental properties are presented and then analysed. The experimental results obtained show that Rades and Gabes sediments could be used as a sand substitute in the formulation of a new construction material. Gabes harbor sediments are more polluted than Rades harbor sediments.

  8. Environmental mechanism of magnetic susceptibility changes of lacustrine sediments from Lake Hulun, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The changes of magnetic susceptibility (κ) are correlated with those of corresponding sedimentological, geochemical, mineralogical and biological results, which verifies that κ can be taken as one of the environmental proxies. However, usually the exact origin of magnetic signal is poorly understood, and is difficult to relate with the environmental evolution. Magnetic properties of material derived from the catchment and sedimentary environment may affect the accumulation, preservation, or authigenesis and diagenesis of magnetic minerals. In the Lake Hulun region in Inner Mongolia, it is found that muddy sediments, deposited during high water level period (corresponding to humid climate), have comparatively high κ values. In contrast, the sandy sediments, deposited during low water level period (corresponding to arid climate), have low κ values. Detailed rock magnetic investigation confirms that detrital magnetite derived from volcanic rocks in the catchment exists in both muddy and sandy sediments. During high water level period, secondary ferrimagnetic iron sulphide was produced in muddy sediments under relatively reductive conditions. Ferrimagnetic iron sulphide, coexisting with detrital magnetite, predominates the magnetic properties of muddy sediments, resulting in increasing κ. This paper reveals the significance of authigenic ferrimagnetic iron sulphide produced after sediment deposition.

  9. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  10. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  11. 78 FR 19357 - Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy

    Science.gov (United States)

    2013-03-29

    ... significant spending cuts known as sequestration and is unavailable for Hurricane Sandy disaster relief. The... January 29, 2013. FTA announced individual allocations on a rolling basis beginning March 6, 2013. Table...

  12. 2012-2013 Post-Hurricane Sandy EAARL-B Submerged Topography - Barnegat Bay, New Jersey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data for part of Barnegat Bay, New Jersey, post-Hurricane Sandy (October 2012 hurricane), were produced from remotely sensed, geographically...

  13. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  14. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  15. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  16. 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New Jersey)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New Jersey CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

  17. 2014 NOAA Ortho-rectified Mosaic of Hurricane Sandy Coastal Impact Area

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles at 0.35m GSD created for NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative in Hurricane Sandy coastal...

  18. Quantitative Retrieval of Soil Nutrient in Sandy Land Based on BJ-1 Multispectral Image

    Science.gov (United States)

    Wu, Junjun; Li, Zengyuan; Gao, Zhihai; Wang, Bengyu; Bai, Lina; Sun, Bin; Li, Changlong; Ding, Xiangyuan

    2014-11-01

    To research an indicator for sandy information, this paper conducts a study on soil nutrient in sandy land. Firstly, the difference of soil nutrient between sandy land and the other was analyzed. Secondly, the correlation between soil nutrient index and band was studied. Then the best inversion band and model was determined and evaluated. Finally, the distribution of soil nutrient was obtained. As the result indicated that the divergence of total nitrogen in different land was the maximum among the three nutrient indicators. With the development of desertification, total nitrogen declined dramatically. The correlation coefficient between each band and total nitrogen was relatively higher, and it reached 0.6. In addition, taking the reciprocal for the sum of three bands as the independent variable was an excellent choice, it could reflect the sandy information better than the single band. The quantitative retrieval model was checked by independent sample, and RMSE was 0.0407.

  19. 2012 USGS EAARL-B Coastal Topography: Post-Sandy, First Surface (NJ)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  20. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  1. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  2. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  3. Effects of ghost shrimp on zinc and cadmium in sediments from Tampa Bay, FL

    Science.gov (United States)

    Klerks, P.L.; Felder, D.L.; Strasser, K.; Swarzenski, P.W.

    2007-01-01

    This study investigated the effects that ghost shrimp have on the distribution of metals in sediment. We measured levels of HNO3-extractable zinc and cadmium in surface sediment, in ghost shrimp burrow walls and in sediment ejected by the ghost shrimp from their burrows, at five sandy intertidal sites in Tampa Bay. Ghost shrimp densities and their rate of sediment ejection were also quantified, as were sediment organic content and silt + clay content. Densities of ghost shrimp (Sergio trilobata and Lepidophthalmus louisianensis) averaged 33/m2 at our sites, and they ejected sediment at an average rate of 28 g/burrow/day. Levels of both Zn and Cd were significantly higher in burrow walls than in surface sediments. Sediment ejected by the shrimp from their burrows had elevated levels of Zn (relative to surface sediments) at one of the sites. Sediment organic content and silt + clay content were higher in burrow-wall sediments than in ejected sediment, which in turn tended to have values above those of surface sediments. Differences in levels of HNO3-extractable Zn and Cd among sediment types may be a consequence of these sediments differing in other physiochemical characteristics, though the differences in metal levels remained statistically significant for some sites after correcting for differences in organic content and silt + clay content. We conclude that the presence of ghost shrimp burrows contributes to spatial heterogeneity of sedimentary metal levels, while the ghost shrimp bioturbation results in a significant flux of metals to the sediment surface and is expected to decrease heterogeneity of metal levels in sedimentary depth profiles.

  4. Water Infiltration and Hydraulic Conductivity in Sandy Cambisols

    DEFF Research Database (Denmark)

    Bens, Oliver; Wahl, Niels Arne; Fischer, Holger

    2006-01-01

    Soil hydrological properties like infiltration capacity and hydraulic conductivity have important consequences for hydrological properties of soils in river catchments and for flood risk prevention. They are dynamic properties due to varying land use management practices. The objective of this st......Soil hydrological properties like infiltration capacity and hydraulic conductivity have important consequences for hydrological properties of soils in river catchments and for flood risk prevention. They are dynamic properties due to varying land use management practices. The objective...... of this study was to characterize the variation of infiltration capacity, hydraulic conductivity and soil organoprofile development on forest sites with comparable geological substrate, soil type and climatic conditions, but different stand ages and tree species in terms of the effects of forest transformation...... from pure Scots pine stands towards pure European beech stands. The water infiltration capacity and hydraulic conductivity (K) of the investigated sandy-textured soils are low and very few macropores exist. Additionally these pores are marked by poor connectivity and therefore do not have any...

  5. Phosphorus fractions in sandy soils of vineyards in southern Brazil

    Directory of Open Access Journals (Sweden)

    Djalma Eugênio Schmitt

    2013-04-01

    Full Text Available Phosphorus (P applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm were collected from a native grassland area and two vineyards, after 14 years (vineyard 1 and 30 years (vineyard 2 of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.

  6. Evaluation of the Intel Sandy Bridge-EP server processor

    CERN Document Server

    Jarp, S; Leduc, J; Nowak, A; CERN. Geneva. IT Department

    2012-01-01

    In this paper we report on a set of benchmark results recently obtained by CERN openlab when comparing an 8-core “Sandy Bridge-EP” processor with Intel’s previous microarchitecture, the “Westmere-EP”. The Intel marketing names for these processors are “Xeon E5-2600 processor series” and “Xeon 5600 processor series”, respectively. Both processors are produced in a 32nm process, and both platforms are dual-socket servers. Multiple benchmarks were used to get a good understanding of the performance of the new processor. We used both industry-standard benchmarks, such as SPEC2006, and specific High Energy Physics benchmarks, representing both simulation of physics detectors and data analysis of physics events. Before summarizing the results we must stress the fact that benchmarking of modern processors is a very complex affair. One has to control (at least) the following features: processor frequency, overclocking via Turbo mode, the number of physical cores in use, the use of logical cores ...

  7. Extraction of sandy bedforms features through geodesic morphometry

    Science.gov (United States)

    Debese, Nathalie; Jacq, Jean-José; Garlan, Thierry

    2016-09-01

    State-of-art echosounders reveal fine-scale details of mobile sandy bedforms, which are commonly found on continental shelfs. At present, their dynamics are still far from being completely understood. These bedforms are a serious threat to navigation security, anthropic structures and activities, placing emphasis on research breakthroughs. Bedform geometries and their dynamics are closely linked; therefore, one approach is to develop semi-automatic tools aiming at extracting their structural features from bathymetric datasets. Current approaches mimic manual processes or rely on morphological simplification of bedforms. The 1D and 2D approaches cannot address the wide ranges of both types and complexities of bedforms. In contrast, this work attempts to follow a 3D global semi-automatic approach based on a bathymetric TIN. The currently extracted primitives are the salient ridge and valley lines of the sand structures, i.e., waves and mega-ripples. The main difficulty is eliminating the ripples that are found to heavily overprint any observations. To this end, an anisotropic filter that is able to discard these structures while still enhancing the wave ridges is proposed. The second part of the work addresses the semi-automatic interactive extraction and 3D augmented display of the main lines structures. The proposed protocol also allows geoscientists to interactively insert topological constraints.

  8. Simulations and Visualizations of Hurricane Sandy (2012) as Revealed by the NASA CAMVis

    Science.gov (United States)

    Shen, Bo-Wen

    2013-01-01

    Storm Sandy first appeared as a tropical storm in the southern Caribbean Sea on Oct. 22, 2012, moved northeastward, turned northwestward, and made landfall near Brigantine, New Jersey in late October. Sandy devastated surrounding areas, caused an estimated damage of $50 billion, and became the second costliest tropical cyclone (TC) in U.S. History surpassed only by Hurricane Katrina (2005). To save lives and mitigate economic damage, a central question to be addressed is to what extent the lead time of severe storm prediction such as Sandy can be extended (e.g., Emanuel 2012; Kerr 2012). In this study, we present 10 numerical experiments initialized at 00 and 1200 UTC Oct. 22-26, 2012, with the NASA coupled advanced global modeling and visualization systems (CAMVis). All of the predictions realistically capture Sandy's movement with the northwestward turn prior to its landfall. However, three experiments (initialized at 0000 UTC Oct. 22 and 24 and 1200 UTC Oct. 22) produce larger errors. Among the 10 experiments, the control run initialized at 0000 UTC Oct. 23 produces a remarkable 7-day forecast. To illustrate the impact of environmental flows on the predictability of Sandy, we produce and discuss four-dimensional (4-D) visualizations with the control run. 4-D visualizations clearly demonstrate the following multiscale processes that led to the sinuous track of Sandy: the initial steering impact of an upper-level trough (appearing over the northwestern Caribbean Sea and Gulf of Mexico), the blocking impact of systems to the northeast of Sandy, and the binary interaction with a mid-latitude, upper-level trough that appeared at 130degrees west longitude on Oct. 23, moved to the East Coast and intensified during the period of Oct. 29-30 prior to Sandy's landfall.

  9. Utilization of Geotextile Tube for Sandy and Muddy Coastal Management: A Review

    OpenAIRE

    Siew Cheng Lee; Roslan Hashim; Shervin Motamedi; Ki-Il Song

    2014-01-01

    Threats to beaches have accelerated the coastal destruction. In recent decades, geotextile tubes were used around the world to prevent coastal erosion, to encourage beach nourishment, and to assist mangrove rehabilitation. However, the applications of geotextile tube in sandy and muddy coasts have different concerns as the geological settings are different. Applications of geotextile tubes in sandy beaches were mainly to prevent coastline from further erosion and to nourish the beach. However...

  10. 33 CFR 165.130 - Sandy Hook Bay, New Jersey-security zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sandy Hook Bay, New Jersey... Specific Regulated Navigation Areas and Limited Access Areas First Coast Guard District § 165.130 Sandy... following boundaries are a security zone: A line beginning on the shore at 40°25′55.6″ N, 074°04′31.4″ W...

  11. Hydrodynamic and Sediment Transport Processes in Long Bay of the Carolinas

    Science.gov (United States)

    Ma, Y.; Xu, K.; He, R.; Wren, P. A.; Gong, Y.; Quigley, B.; Tarpley, D.

    2010-12-01

    The coastline along Long Bay of the Carolinas is a fast-growing and heavily-developed area supporting local populations, infrastructure, and a large tourism industry. Myrtle Beach and its adjacent sandy beaches are popular tourist destinations that attract millions of visitors each year, representing one of the state’s most essential natural resources. The economy of this region is closely related to the stability of the sandy beaches, which are vulnerable to coastal erosion during severe storm events. Quantifying the sediment transport processes in the nearshore and inner continental shelf regions is thus critical for both understanding the regional sediment budget and implementing effective coastal management. As a first step toward investigating the sediment transport processes, a three-dimensional coupled hydrodynamic-sediment transport model for Long Bay in the Carolinas has been developed. The model, based on the Regional Ocean Modeling System (ROMS), spans from Cape Fear estuary in NC to Winyah Bay estuary in SC. It considers the delivery of fluvial sediment from the Cape Fear and Pee Dee Rivers, resuspension from seabed, and transport of suspended sediment by ambient currents and waves calculated using Simulating WAve Nearshore model (SWAN). Our model simulations are driven by observed wind fields, which were collected at nearby meteorological stations maintained by National Data Buoy Center as well as at six buoys by the Palmetto Wind Research Project at Coastal Carolina University. Spatially varying sea bed conditions consisting of both hard bottoms and sandy bodies are applied in the calculation. The model is one-way nested inside a large-scale coastal circulation model that covers both the Middle Atlantic Bight and the South Atlantic Bight and provides dynamically consistent and numerically accurate circulation open boundary conditions. Modeling results indicate both wind-driven currents and storm-induced waves are capable of resuspending sandy

  12. Petroleum-influenced beach sediments of the campeche bank, Mexico: Diversity and bacterial community structure assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rosano-Hernandez, M. C.; Ramirez-Saad, H.; Fernandez-Linares, L.; Xoconostle, B.

    2009-07-01

    In Mexican, either spilled or seeped out petroleum impacts nearly 300 km of the beach between Dos Bocas (Tabasco State) to Champoton town (Campeche State), where between 9 to exceptionally 9 to exceptionally 300 tonnes of oil as tar balls have been measured. This study was focused to explore, for the first time, the bacterial diversity and community structure ({alpha}-diversity)- in a kilometric scale on petroleum influenced sediments of 100 km of sandy beach. (Author)

  13. Nonfatal injuries 1 week after hurricane sandy--New York city metropolitan area, October 2012.

    Science.gov (United States)

    Brackbill, Robert M; Caramanica, Kimberly; Maliniak, Maret; Stellman, Steven D; Fairclough, Monique A; Farfel, Mark R; Turner, Lennon; Maslow, Carey B; Moy, Amanda J; Wu, David; Yu, Shengchao; Welch, Alice E; Cone, James E; Walker, Deborah J

    2014-10-24

    On October 29, 2012, Hurricane Sandy (Sandy) made landfall in densely populated areas of New York, New Jersey, and Connecticut. Flooding affected 51 square miles (132 square kilometers) of New York City (NYC) and resulted in 43 deaths, many caused by drowning in the home, along with numerous storm-related injuries. Thousands of those affected were survivors of the World Trade Center (WTC) disaster of September 11, 2001 (9/11) who had previously enrolled in the WTC Health Registry (Registry) cohort study. To assess Sandy-related injuries and associated risk factors among those who lived in Hurricane Sandy-flooded areas and elsewhere, the NYC Department of Health and Mental Hygiene surveyed 8,870 WTC survivors, who had provided physical and mental health updates 8 to 16 months before Sandy. Approximately 10% of the respondents in flooded areas reported injuries in the first week after Sandy; nearly 75% of those had more than one injury. Injuries occurred during evacuation and clean-up/repair of damaged or destroyed homes. Hurricane preparation and precautionary messages emphasizing potential for injury hazards during both evacuation and clean-up or repair of damaged residences might help mitigate the occurrence and severity of injury after a hurricane.

  14. Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

    Directory of Open Access Journals (Sweden)

    M. Kunz

    2013-10-01

    Full Text Available At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

  15. Hurricane Sandy Exposure and the Mental Health of World Trade Center Responders.

    Science.gov (United States)

    Bromet, Evelyn J; Clouston, Sean; Gonzalez, Adam; Kotov, Roman; Guerrera, Kathryn M; Luft, Benjamin J

    2017-04-03

    The psychological consequences of a second disaster on populations exposed to an earlier disaster have rarely been studied prospectively. Using a pre- and postdesign, we examined the effects of Hurricane Sandy on possible World Trade Center (WTC) related posttraumatic stress disorder (PTSD Checklist score of ≥ 50) and overall depression (major depressive disorder [MDD]; Patient Health Questionnaire depression score of ≥ 10) among 870 WTC responders with a follow-up monitoring visit at the Long Island WTC Health Program during the 6 months post-Hurricane Sandy. The Hurricane Sandy exposures evaluated were damage to home (8.3%) and to possessions (7.8%), gasoline shortage (24.1%), prolonged power outage (42.7%), and filing a Federal Emergency Management Agency claim (11.3%). A composite exposure score also was constructed. In unadjusted analyses, Hurricane Sandy exposures were associated with 1.77 to 5.38 increased likelihood of PTSD and 1.58 to 4.13 likelihood of MDD; odds ratios for ≥ 3 exposures were 6.47 for PTSD and 6.45 for MDD. After adjusting for demographic characteristics, WTC exposure, pre-Hurricane Sandy mental health status, and time between assessments, reporting ≥ 3 Hurricane Sandy exposures was associated with a 3.29 and 3.71 increased likelihood of PTSD and MDD, respectively. These findings underscore the importance of assessing the impact of a subsequent disaster in ongoing responder health surveillance programs.

  16. Evaluation of power outages in Connecticut during hypothetical future Hurricane Sandy scenarios

    Science.gov (United States)

    Wanik, D. W.; Anagnostou, E. N.; Astitha, M.; Frediani, M. E.; Yang, J.

    2015-12-01

    Reliable electric power is a staple of our modern society.The purpose of this work was to evaluate the occurrence of power outages under more intense, future Hurricane Sandy simulations in Connecticut. In addition, we also evaluated how many crews would be necessary to restore power in 7 days, and how different vegetation scenarios might contribute to a decrease in outages. We trained five pairwise models on each current Sandy runs (2012) as training using the random forest model (each validated using 10-fold cross-validation), and used each future Sandy run as an independent test. We predict that a future Sandy would have 2.5x as many outages as current Sandy, which would require 3.23x as many crews as current Sandy to restore power in 7 days. We also found that increased vegetation management might decrease outages, which has implications for both fair-weather and storm days of all types (i.e. blizzards, thunderstorms, ice storms). Although we have only evaluated outages for electric distribution networks, there are many other types (water supply, wastewater, telecommunications) that would likely benefit from an analysis of this type. In addition, given that we have the weather simulations already processed within our 2-km weather simulation domain, we would like to expand our vulnerability analyses to surrounding utilities in New Jersey, New York, Rhode Island, Massachusetts and New Hampshire to facilitate regional coordination among electric distribution networks.

  17. Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

    Science.gov (United States)

    Kunz, M.; Mühr, B.; Kunz-Plapp, T.; Daniell, J. E.; Khazai, B.; Wenzel, F.; Vannieuwenhuyse, M.; Comes, T.; Elmer, F.; Schröter, K.; Fohringer, J.; Münzberg, T.; Lucas, C.; Zschau, J.

    2013-10-01

    At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation) and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

  18. Hurricane Sandy (New Jersey): Mortality Rates in the Following Month and Quarter.

    Science.gov (United States)

    Kim, Soyeon; Kulkarni, Prathit A; Rajan, Mangala; Thomas, Pauline; Tsai, Stella; Tan, Christina; Davidow, Amy

    2017-08-01

    To describe changes in mortality after Hurricane Sandy made landfall in New Jersey on October 29, 2012. We used electronic death records to describe changes in all-cause and cause-specific mortality overall, in persons aged 76 years or older, and by 3 Sandy impact levels for the month and quarter following Hurricane Sandy compared with the same periods in earlier years adjusted for trends. All-cause mortality increased 6% (95% confidence interval [CI] = 2%, 11%) for the month, 5%, 8%, and 12% by increasing Sandy impact level; and 7% (95% CI = 5%, 10%) for the quarter, 5%, 8%, and 15% by increasing Sandy impact level. In elderly persons, all-cause mortality rates increased 10% (95% CI = 5%, 15%) and 13% (95% CI = 10%, 16%) in the month and quarter, respectively. Deaths that were cardiovascular disease-related increased by 6% in both periods, noninfectious respiratory disease-related by 24% in the quarter, infection-related by 20% in the quarter, and unintentional injury-related by 23% in the month. Mortality increased, heterogeneous by cause, for both periods after Hurricane Sandy, particularly in communities more severely affected and in the elderly, who may benefit from supportive services.

  19. Study of spatial distribution of sandy desertification in North China in recent 10 years

    Institute of Scientific and Technical Information of China (English)

    WANG Tao; WU Wei; XUE Xian; SUN Qingwei; CHEN Guangting

    2004-01-01

    Sandy desertification is a land degradation characterized by wind erosion, mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in North China. It is one of main kinds of desertification/land degradation as well as water-soil erosion and salinization in China. Rapid and continuous spread of sandy desertification during last 50 years has created a major environmental and socio-economic problem in North China. Remote sensing monitored results in 2000 showed that the sandy desertified land area has been 38.57×104 km2. The area of potential to slightly sandy desertified land is 13.93×104 km2, moderately land 9.977×104 km2, severely land 7.909×104 km2 and very severely land 6.756×104km2. Sandy desertification mainly occurs in the semi-arid mixed farming-grazing zone and its northern rangeland zone, semi-arid dryland rainfed cropping zone and arid oasis-desert margin zone. The average annually developmental rate of sandy desertified land increased from 2,100tion in North China is "overall deterioration, while local rehabilitation". Already achieved rehabilitation results and monitoring assessment show that about 60% of desertified land in North China can be restored under the conditions of rational land-use ways and intensity.

  20. EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

    Directory of Open Access Journals (Sweden)

    Patrick S. Michael

    2015-08-01

    Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

  1. IMPROVEMENT OF SANDY SOIL WITH WATER-CONSERVING MEMBRANE AND ITS EFFECT ON CROP GROWTH

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-jun; CUI Xiang-hao; LI Qu-sheng

    2005-01-01

    Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and Ph of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary,promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.

  2. FACIES ANALYSIS, STRATIGRAPHY AND PALAEONTOLOGY (MOLLUSCS AND VERTEBRATES IN THE UPPER PLIOCENE SANDY FLOOD-BASIN DEPOSITS OF THE UPPER VALDARNO BASIN (NORTHERN APENNINES

    Directory of Open Access Journals (Sweden)

    MASSIMILIANO GHINASSI

    2005-11-01

    Full Text Available The Upper Valdarno Basin, one of the most investigated Neogene–Quaternary basins of the Northern Apennines, developed during three main phases, as testified by the occurrence of three unconformity-bounded stratigraphic units (UBSUs in the basin infill. Despite numerous studies having been carried out, biochronological, paleoecological and stratigraphical issues in the lower portion of the Montevarchi Synthem (second phase have yet to be understood. Sandy deposits (Montecarlo Sand and Silt Unit, stratigraphically located in this portion of the Montevarchi Synthem, are the focus of this multidisciplinary study. These deposits conformably overlie sandy fluvio-eolian sediments and are, in turn, capped by fluvio-palustrine deposits through a progressive unconformity. Facies analysis suggest a sandy flood-basin environment for these deposits, characterised by variations in water discharge and flood event energy. Mollusc and fish remains, pointing to quiet or slow-moving shallow waters, have been affected by transport processes before final burial in overbank areas. Fish remains of the primary marine family Mugilids highlight a connection between the basin and the sea that was previously only supposed. Small mammal remains, referred to the rodent Mimomys polonicus, are coherent with a water-rich environment. Cyclic variations in shell content and sedimentological characteristics testify to the occurrence of short-term climatic oscillations during this warming phase. This study fits with paleomagnetic and radiometric datings and mammal biochronology, in indicating that the Montecarlo Sand and Silt Unit belongs to a time interval preceding the Reunion paleomagnetic event. The depositional evolution of the Montecarlo Unit was driven by climatic change from arid to humid conditions, related to a global increase in temperature that occurred between 2.4 and 2.2 Ma.

  3. Rates of nitrification, distribution of nitrifying bacteria and inorganic N fluxes in northern Bering-Chukchi shelf sediments

    Science.gov (United States)

    Henriksen, K.; Blackburn, T. H.; Lomstein, B. Aa.; McRoy, C. P.

    1993-05-01

    Spatial distribution of sediment nitrification rates and fluxes of ammonium and nitrate were measured in shelf sediments of the northern Bering and Chukchi seas. The sediments could be divided into three main areas depending on macrofaunal activity and input of organic nitrogen. Sediments underlying the highly productive Bering Shelf-Anadyr water (BSAS) were characterized by a high macrofaunal biomass and a high input of nitrogen-rich organic material. Tube-dwelling amphipods dominated in the sandy sediments of the northern Bering Sea, while bivalves dominated in the fine textured sediments of the Chukchi Sea. Sediments underlying the low productive Alaska Coastal Water (ACS) were characterized by low macrofaunal biomass and an input of lower quality organic material. Generally nitrification rates and nutrification potentials (NP) were highest in BSAS and lower in ACS. Nitrification rates of surface sediment, calculated from NP, accounted for 90% of the measured rates in ACS, but only 35-75% in BSAS. These data together with the distribution patterns of NP and pore water nitrate profiles implied, that most sediment nitrification was confined to the sediment surface in ACS and in BSAS bivalve sediments, while most sediment nitrification took place in the ventilated burrow walls of BSAS amphipod sediments. The NH 4+ efflux was five-fold greater from BSAS compared to ACS, whereas the estimated sediment net NH 4+ production was three-fold greater. The increase in NH 4+ efflux relative to net NH 4+ production could mostly be attributed to macrofaunal excretion. The NO 3- flux between sediment and water column was correlated with NO 3- concentrations in the bottom water. At concentrations higher than 10 μM NO 3-, the flux was directed into the sediment and at lower concentrations out of the sediment. Spatial distribution of high bottom water NO 3- concentrations correlated with high NH 4+ fluxes out of the sediment. This resulted in a lower net efflux of inorganic

  4. NEPTUNIUM IV AND V SORPTIN TO END-MEMBER SUBSURFACE SEDIMENTS TO THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D.

    2009-11-13

    Migration of Np through the subsurface is expected to be primarily controlled by sorption to sediments. Therefore, understanding and quantifying Np sorption to sediments and sediments from the Savannah River Site (SRS) is vital to ensure safe disposal of Np bearing wastes. In this work, Np sorption to two sediments representing the geological extremes with respect to sorption properties expected in the SRS subsurface environment (named 'subsurface sandy sediment' and 'subsurface clayey sediment') was examined under a variety of conditions. First a series of baseline sorption tests at pH 5.5 under an oxic atmosphere was performed to understand Np sorption under typical subsurface conditions. These experiments indicated that the baseline K{sub d} values for the subsurface sandy and subsurface clayey sediments are 4.26 {+-} 0.24 L kg{sup -1} and 9.05 {+-} 0.61 L kg{sup -1}, respectively. These Np K{sub d} values of SRS sediments are the first to be reported since Sheppard et al. (1979). The previous values were 0.25 and 0.16 L kg{sup -1} for a low pH sandy sediment. To examine a possible range of K{sub d} values under various environmental scenarios, the effects of natural organic matter (NOM, also a surrogate for cellulose degradation products), the presence of various chemical reductants, and an anaerobic atmosphere on Np sorption were examined. The presence of NOM resulted in an increase in the Np K{sub d} values for both sediments. This behavior is hypothesized to be the result of formation of a ternary Np-NOM-sediment complex. Slight increases in the Np sorption (K{sub d} 13-24 L kg{sup -1}) were observed when performing experiments in the presence of chemical reductants (dithionite, ascorbic acid, zero-valent iron) or under anaerobic conditions. Presumably, the increased sorption can be attributed to a slight reduction of Np(V) to Np(IV), the stronger sorbing form of Np. The most significant result of this study is the finding that Np weakly

  5. Assessing the relative role of climate change and human activities in sandy desertification of Ordos region, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Climate change and human activities are driving forces of sandy desertification and the relative role of them in sandy desertification is the hot point in related researches. A study was carried to assess the relative role of climate change and human activities in sandy desertification of Ordos region in China. Potential NPP and the difference between potential and actual NPP were selected as indicators to assess the relative role of climate change and human activities in sandy desertification, respectively. Assessing methods were built based on some scenarios for the reversion and expansion of sandy desertification and the relative role of climate change and human activities in sandy desertification of Ordos region were assessed from 1981 to 2000. The results showed that although some local places experienced an expansion of sandy desertification, the change of sandy desertification of Ordos region from 1981 to 2000 showed a stably reversing trend. The relative role of climate change and human activities in sandy desertification of Ordos region varied at different temporal and spatial scales in the reversion and expansion processes. In the reversion of sandy desertification, climate change was the dominant factor in the period of 1981 to 1990 and the reversed areas mainly induced by climate change including Mu Us sandy land and the transition zone between temperate steppe and temperate deciduous scrubs in north east of Ordos region; however, human activities controlled the reversed process during the period from 1991 to 2000 and the areas mainly induced by human activities distributed in all banners of Ordos region. In the expansion of sandy desertification, human activities were the dominant factor in the period of 1981 to 1990 and the expanded areas mainly included the regions around common boundary of Hanggin, Dalad Banners and Dongsheng City; however, climate change dominated the expansion of sandy desertification from 1991 to 2000, the expanded areas equably

  6. Spatial and temporal changes in interstitial meiofauna on a sandy ocean beach of South America

    Directory of Open Access Journals (Sweden)

    Elaine F. Albuquerque

    2007-06-01

    Full Text Available Spatial and temporal patterns of meiofauna community from a Brazilian sandy beach were investigated. The objective of this work was to analyze the meiofauna distribution using a statistical model that considers the biological data as variables, and granulometric characteristics, organic matter, and temperature as covariables.Four zones were sampled throughout one year in a Brazilian sandy beach and three sediment cores were taken monthly from each zone. The meiofauna was composed by 12 taxa, with tardigrades and nematodes comprising 92% of the total fauna. The meiofauna mean density varied from 1556.25 to 13125.25 ind.10 cm-2, with the highest densities in December. The results of multiple regression showed that the mean effects of zones, vertical layers, and months on the organisms were significantly correlated with the principal taxa of meiofauna. The retention zone and the 0-10 cm layer presented the highest densities. The temporal distribution showed different patterns and some taxa were more abundant in the dry season, and others in the rainy season. Sedimentological variables had strong and significant effects on the meiofauna taxa. According to the results, physical variables at the retention zone create optimal living conditions for the meiobentos, making this zone an area that favors the basic and applied ecological studies.Os padrões de distribuição espacial e temporal da meiofauna em uma praia arenosa do Brasil foram analisados usando um modelo estatístico que considerou os dados biológicos como variáveis e as características granulométricas, % de matéria orgânica, temperatura como covariáveis. Quatro zonas litorais foram amostradas durante o período de um ano e três cores de sedimento foram coletados em cada zona. A meiofauna foi composta de 12 taxa principais e os Tardigrada e Nematoda representaram 92% da fauna total. A densidade média da meiofauna variou de 1.556,25 a 13.125,25 ind.10cm-2, com as mais altas

  7. Distribution and characteristics of methylmercury in surface sediment in Minamata Bay.

    Science.gov (United States)

    Matsuyama, Akito; Yano, Shinichiro; Hisano, Akihiro; Kindaichi, Michiaki; Sonoda, Ikuko; Tada, Akihide; Akagi, Hirokatsu

    2016-08-15

    This study was carried out to evaluate the present-day chemical properties of methylmercury in surface sediment in Minamata Bay where a dredging project was completed 28years ago. Present-day sediment from Minamata Bay consists of sandy silt, and the average loss-on-ignition in surface sediment was 7.0±2.3%. The average methylmercury concentrations in the upper sediment layers were significantly higher than those in the lower sediment layers. Currently, the concentrations in sediments in Minamata Bay do not exceed the Japanese regulatory standard value for mercury. The average concentration of methylmercury in Minamata Bay surface sediment was 1.74±1.0ng/g on a dry weight basis (n=107). The methylmercury concentration in Minamata Bay surface sediment was almost 16 times higher than that in surface sediment from Isahaya Bay surface sediment, which was 0.11±0.045ng/g on a dry weight basis (n=5).

  8. Character and provenance of aeolian sediments in northeast Thailand

    Science.gov (United States)

    Nichol, Janet E.; Nichol, Douglas W.

    2015-12-01

    Aeolian activity is not generally associated with the humid tropics, and although reports of loess-like soils in various locations in southeast Asia exist, these mainly lack the detailed analysis to set them in meaningful spatial or historical context. This paper examines the red and yellow sandy sediments of the Khorat Plateau in northeast Thailand which have been variously referred to as 'cover sands', 'loessial soils' or 'loess'. The sediments are referred to as having alluvial, biological as well as aeolian origin, and a date of 9-35 ka is reported. The study compares the Khorat sediments physically and geochemically with loess and aeolian sediments from other regions, as well as with other sites in southeast Asia which are reported here. The moderate degree of particle sorting and unimodal sizes of the sediments along with a sub-spherical sub-rounded form, supports previous diagnoses of an aeolian origin. Geochemical analysis of the Khorat sediments indicates severe depletion in both mobile and immobile elements, which are even more depleted than other southeast Asian loessic soils examined. This depletion, along with the only moderate particle sorting, suggests the source of the sediments to be the local weathered sandstones outcropping around the edge of the Khorat Plateau. The dissimilarity of the Khorat sediments from Upper Continental Crust (UCC) elemental values supports this, as homogenisation would occur if diverse source areas were involved. The study suggests that aeolian sediments of humid tropical regions warrant more attention as climate proxy markers, due to the dissimilarity between the present climate and conditions required for their formation.

  9. Behavior and Fate of PFOA and PFOS in Sandy Aquifer ...

    Science.gov (United States)

    Microcosms were constructed with sediment from beneath a landfill that received waste containing PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate). The microcosms were amended with PFOA and PFOS, and sampled after 91, 210, 343, 463, 574, and 740 days of incubation. After 740 days, selected microcosms were extracted to determine the mass of PFOA and PFOS remaining. There was no evidence for degradation of PFOA or PFOS. Over time, the aqueous concentrations of PFOA and PFOS increased in the microcosms, indicating that PFOA and PFOS that had originally sorbed to the sediment was desorbing. At the beginning of the experiment, the adsorption coefficient, Kd, averaged 0.27 L/kg for PFOA and 1.2 L/kg for PFOS. After 740 days of incubation, sorption of PFOA was not detectable and the Kd of PFOS was undetectable in two microcosms and was 0.08 L/kg in a third microcosm. During incubation, the pH of the pore water in the microcosms increased from pH 7.2 to pH ranging from 8.1 to 8.8 and the zeta potential of the sediment decreased with increasing pH. These observations suggest sorption of PFOA and PFOS was controlled by electrostatic sorption on ferric oxide minerals, and not by sorption to organic carbon. These observations suggest sorption of PFOA and PFOS was controlled by electrostatic sorption on ferric oxide minerals, and not by sorption to organic carbon.

  10. Diesel and silica monitoring at two sites following hurricane sandy.

    Science.gov (United States)

    Freund, Alice; Zuckerman, Norman; Luo, Honghong; Hsu, Hsiao-Hsien; Lucchini, Roberto

    2014-01-01

    Following Hurricane Sandy, which hit New York City and New Jersey in October 2012, industrial hygienists from the Mount Sinai and Belleview/New York University occupational medicine clinics conducted monitoring for diesel exhaust and silica in lower Manhattan and Rockaway Peninsula. Average daytime elemental carbon levels at three stations in lower Manhattan on December 4, 2012, ranged from 9 to18 μg/m(3). Sub-micron particle counts at various times on the same day were over 200,000 particles per cubic centimeter on many streets in lower Manhattan. In Rockaway Peninsula on December 12, 2012, all average daytime elemental carbon levels were below a detection limit of approximately 7 μg/m(3). The average daytime crystalline silica dust concentration was below detection at two sites on Rockaway Peninsula, and was 0.015 mg/m(3) quartz where sand was being replaced on the beach. The daily average levels of elemental carbon and airborne particulates that we measured are in the range of levels that have been found to cause respiratory effects in sensitive subpopulations like asthmatic patients after 2 hr of exposure. Control of exposure to diesel exhaust must be considered following natural disasters where diesel-powered equipment is used in cleanup and recovery. Although peak silica exposures were not likely captured in this study, but were reported by a government agency to have exceeded recommended guidelines for at least one cleanup worker, we recommend further study of silica exposures when debris removal operations or traffic create visible levels of suspended dust from soil or sand.

  11. Release behavior of copper and zinc from sandy soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-kui; XIA Yi-ping

    2005-01-01

    The concentrations and chemical forms of copper(Gu) and zinc(Zn) in surface soils directly influence the movement of Gu and Zn. In this study, thirteen sandy soil samples with a wide range of total Cu and Zn concentrations were collected for evaluating the relationships between Cu and Zn release and extraction time, ratio of soil to water, pH and electrolyte types. The results indicated that Cu released in batch extraction that represents long-term leaching was mainly from exchangeable, and carbonate bound Cu fractions, and Zn released in the batch extraction was mainly from its carbonate bound fraction. However, the Cu and Zn leached from the soils using the column leaching that represents short-term leaching were mainly from their exchangeable fractions. Soil column leaching at different pH values indicated that the amounts of leached Zn and Cu were greatly affected by pH. The Cu and Zn release experiments with varying extraction times and ratio of soil to water suggest that long-term water-logging in the soils after rain may increase contact time of the soils with water and the release of Cu and Zn to water from the soils, and total amounts of Cu or Zn released from the soils increase, but the Cu or Zn concentration in the surface runoff decrease with increasing rainfall intensity. The increased Ca concentration in soil solution increased stability of organic matter-mineral complexes and might decrease the dissolution of organic matter, and thus decreased the release of Cu-binding component of organic matter. However, high concentration of Na in the soil solution increased the dispersion of the organic matter-mineral complexes and increased dissolution of organic matter and the release of Cu from the soils.

  12. Alluvial fan dynamics in the El'gygytgyn Crater: implications for the 3.6 Ma old sediment archive

    Directory of Open Access Journals (Sweden)

    G. Schwamborn

    2012-06-01

    Full Text Available A sedimentological program has been conducted using frozen core samples from the 141.5 m long El'gygytgyn 5011-3 permafrost well. The drill site is located in sedimentary permafrost west of the lake that partly fills the El'gygytgyn Crater. The total core sequence is interpreted as strata building up a progradational alluvial fan delta. Four structurally and texturally distinct sedimentary units are identified. Unit 1 (141.5–117.0 m is comprised of ice-cemented, matrix-supported sandy gravel and intercalated sandy layers. Sandy layers represent sediments which rained out as particles in the deeper part of the water column under highly energetic conditions. Unit 2 (117.0–24.25 m is dominated by ice-cemented, matrix-supported sandy gravel with individual gravel layers. Most of the unit 2 diamicton is understood to result from alluvial wash and subsequent gravitational sliding of coarse-grained material on the basin slope. Unit 3 (24.25–8.5 m has ice-cemented, matrix-supported sandy gravel that is interrupted by sand beds. These sandy beds are associated with flooding events and represent near-shore sandy shoals. Unit 4 (8.5–0.0 m is ice-cemented, matrix-supported sandy gravel with varying ice content, mostly higher than below. It consists of slope material and creek fill deposits. The uppermost meter is the active layer into which modern soil organic matter has been incorporated. The nature of the progradational sediment transport taking place from the western and northern crater margins may be related to the complementary occurrence of frequent turbiditic layers in the central lake basin as is known from the lake sediment record. Slope processes such as gravitational sliding and sheet flooding that takes place especially during spring melt are thought to promote mass wasting into the basin. Tectonics are inferred to have initiated the fan accumulation in the first place and possibly the off-centre displacement of the crater lake.

  13. Influence of host plants and soil diluents on arbuscular mycorrhizal fungus propagation for on-farm inoculum production using leaf litter compost and agrowastes

    Science.gov (United States)

    Arbuscular mycorrhizal (AM) fungi (Claroideoglomus etunicatum NNT10, C. etunicatum PBT03 and Funneliformis mosseae RYA08) were propagated using different culture materials (sterile sandy soil by itself or mixed 1:1 (v/v) with clay-brick granules, rice husk charcoal, or vermiculite) and host plants (...

  14. Morphological records of storm floods exemplified by the impact of the 1872 Baltic storm on a sandy spit system in south-eastern Denmark

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Bendixen, Mette; Hede, Mikkel Ulfeldt

    2014-01-01

    Beach-ridge systems are important geo-archives providing evidence for past wave climate including catastrophic storm flood events. This study investigates the morphological impacts of the 1872 Baltic storm flood on a beach-ridge system (sandy spit) in south-eastern Denmark and evaluates...... the dune ridge at several sites and wash-over fans were generated until a level where the mean water level had dropped too much. Phase 4: the non-vegetated wash-over fans functioned as pathways for aeolian sand transport and relatively high dunes were formed in particular along the margins of the fan where...... aeolian sand was trapped by existing vegetation. The studied beach-ridge system records about 4500 years of accumulation; the storm flood sediments described are unique suggesting that the 1872 Baltic storm flood event was an extreme event. Thus studies of beach-ridge systems form a new source...

  15. A quantitative analysis on the sources of dune sand in the Hulun Buir Sandy Land:application of stepwise discriminant analysis (SDA) to the granulometric data

    Institute of Scientific and Technical Information of China (English)

    HANGuang; ZHANGGuifang; YANGWenbin

    2004-01-01

    Quantltatively determining the sources of dune sand uis one of the problems necessarily and urgently to be solved in aeolian landforms and desertification research. Based on the granulometric data of sand materials from the Hulun Buir Sandy Land, the paper employs the stepwise discriminant analysis technique (SDA) for two groups to select the principal factors determining the differences between surface loose sediments. The extent of similarity between two statistical populations can be described quantitatively by three factors such as the number of principal variables, Mahalanobis distance D2 and confidence level α for F-test. Results reveal that: 1) Aeolian dune sand in the region mainly derives from Hailar Formation (Q3), while fluvial sand and palaeosol also supply partially source sand for dunes; and 2) in the vicinity of Cuogang Town and west of the broad valley of the lower reaches of Hailar River, fluvial sand can naturally become principal supplier for dune sand.

  16. Morphological records of storm floods exemplified by the impact of the 1872 Baltic storm on a sandy spit system in south-eastern Denmark

    DEFF Research Database (Denmark)

    Clemmensen, Lars B.; Bendixen, Mette; Hede, Mikkel U.

    2014-01-01

    Beach-ridge systems are important geo-archives providing evidence for past wave climate including catastrophic storm flood events. This study investigates the morphological impacts of the 1872 Baltic storm flood on a beach-ridge system (sandy spit) in south-eastern Denmark and evaluates...... the frequency of extreme storm flood events in the area over a longer time perspective. This paper combines field studies of morphology and sedimentary deposits, studies of historical maps, digital terrain model, ground-penetrating radar profiles, and luminescence dating. Sea water reached 2.8 m above mean sea...... level (amsl) during peak inundation and, based on studies of the morphological impacts of the 1872 storm flood, the event can be divided into four phases. Phase 1: increasing mean water levels and wave activity at the beach brought sediments from the beach (intertidal bars and normal berm) higher up...

  17. Morphological impacts of extreme storms on sandy beaches and barriers

    Science.gov (United States)

    Morton, R.A.; Sallenger, A.H.

    2003-01-01

    Historical extreme storms that struck the Gulf Coast and Atlantic Coast regions of the United States caused several different styles of morphological response and resulted in a wide range of washover penetration distances. The post- storm erosional responses included dune scarps, channel incisions, and washouts, whereas depositional responses included perched fans, washover terraces, and sheetwash lineations. Maximum inland extent of washover penetration ranged from approximately 100 to 1000 m and estimated sediment volumes associated with these deposits ranged from about 10 to 225 m 3/m of beach. Unusual styles of morphological response (sheetwash lineations and incised channels) and maximum washover penetration distances are closely correlated, and they also correspond to storm intensity as denned by the Saffir-Simpson wind-speed scale. The regional morphological responses and washover penetration distances are controlled primarily by the interactions among heights and durations of storm surge relative to adjacent land elevations, differences in water levels between the ocean and adjacent lagoon, constructive and destructive interference of storm waves, and alongshore variations in nearshore bathymetry. For barrier segments that are entirely submerged during the storm, impacts can be enhanced by the combined influences of shallow water depths and organized flow within the wind field. The greatest washover penetrations and sediment accumulations are products of shallow water, confined flow, and high wind stress. Transport and deposition of washover sediments across barrier islands and into the adjacent lagoon are common processes along the Gulf of Mexico but not along the western Atlantic Ocean. This fundamental difference in storm impact underscores how microtidal and mesotidal barriers respond respectively to extreme storms, and provides insight into how different types of barrier islands will likely respond to future extreme storms and to a relative rise in sea

  18. The influence of turbulent bursting on sediment resuspension under unidirectional currents

    Directory of Open Access Journals (Sweden)

    S. Salim

    2017-07-01

    Full Text Available Laboratory experiments were conducted in an open channel flume with a flat sandy bed to examine the role of turbulence on sediment resuspension. An acoustic Doppler velocimeter (ADV was used to measure the instantaneous three-dimensional velocity components and acoustic backscatter as a proxy to suspended sediment concentration. Estimates of sediment transport assume that there is a mean critical velocity that needs to be exceeded before sediment transport is initiated. This approach does not consider the turbulent flow field that may initiate sediment resuspension through event-based processes such as the bursting phenomenon. In this paper, laboratory measurements were used to examine the sediment resuspension processes below and above the mean critical velocity. The results within a range above and below the measured mean critical velocity suggested that (1 the contribution of turbulent bursting events remained identical in both experimental conditions, (2 ejection and sweep events contributed more to the total sediment flux than up-acceleration and down-deceleration events, and (3 wavelet transform revealed a correlation between the momentum and sediment flux in both test conditions. Such similarities in conditions above and below the measured mean critical velocity highlight the need to re-evaluate the accuracy of a single time-averaged mean critical velocity for the initiation of sediment entrainment.

  19. Experimental Investigation on Flow Characteristics at Leeside of Suspended Flexible Curtain for Sedimentation Enhancement

    Institute of Scientific and Technical Information of China (English)

    LI Yan-hong; YU Guo-liang

    2009-01-01

    A new patent registered device-suspended flexible curtain (SFC) for sedimentation enhancement is proposed in this paper, which consists of two parts: a hght-weight curtain with sediment-passing windows and a heavy pillar for the device stability. The mechanism of trapping nearbed sediment by the SFC is such that a primary and a secondary circulations with horizontal hubs would be formed at the leeside when it is placed on beds in running flow; the velocities within the sediment-passing windows are locally accelerated, the nearbed sediments would be brought by the flow through the win-dows, and then settled down within the primary circulation zone. Experimental tests on hydraulic characteristics are con-ducted in a laboratory flume with rigid bed. It is found that the dimensions of the curtain and the sediment-passing win-dows determine the characteristics of the primary and the secondary circulations. The intensity of the primary and the sec-ondary circulations is dominated by the size of the sediment-passing window. Whether the secondary circulation would contact the bed or not depends on the level of the sediment-passing window. The length and the height of the primary cir-culation zone demonstrate quasi linear relationships with the effective height of the SFC. And the tests on sandy bed flume show that the sediment deposition happens just in the primary circulation zone.

  20. Distribution of surficial sediments in the Southern Evoikos and Petalioi Gulfs, Greece

    Directory of Open Access Journals (Sweden)

    A.P. KARAGEORGIS

    2012-12-01

    Full Text Available A series of 123 surficial sediment samples from the Southern Evoikos and Petalioi Gulfs was studied for grain-size properties, carbonate content and mineralogical composition. Distribution of the sediments revealed two sedimentary provinces. The first concerns the Southern Evoikos Gulf, characterised by silty sediments with relatively low carbonate content. Quartz, feldspars, micas, clay and carbonate minerals are the major mineralogical components of the sediments. These sediments are the result of the Asopos River supply during Holocene and they contribute to the formation of smooth bottom morphology. The second province concerns the Petalioi Gulf (Northern and Southern, where the surficial sediments are mainly sandy and characterised by very high carbonate content. Their mineralogical composition reflects the lithology of the drainage basin. Since the modern terrigenous solid supply is limited, these sediments are not considered as products of recent sedimentation, but older deposits (relict sands. Their presence at such depths is justified by sea-level fluctuations and their preservation is due to the low sedimentation rate in the Petalioi Gulf, in combination with the strong hydrodynamic status of the area.

  1. Genesis of Hurricane Sandy (2012) Simulated with a Global Mesoscale Model

    Science.gov (United States)

    Shen, Bo-Wen; DeMaria, Mark; Li, J.-L. F.; Cheung, S.

    2013-01-01

    In this study, we investigate the formation predictability of Hurricane Sandy (2012) with a global mesoscale model. We first present five track and intensity forecasts of Sandy initialized at 00Z 22-26 October 2012, realistically producing its movement with a northwestward turn prior to its landfall. We then show that three experiments initialized at 00Z 16-18 October captured the genesis of Sandy with a lead time of up to 6 days and simulated reasonable evolution of Sandy's track and intensity in the next 2 day period of 18Z 21-23 October. Results suggest that the extended lead time of formation prediction is achieved by realistic simulations of multiscale processes, including (1) the interaction between an easterly wave and a low-level westerly wind belt (WWB) and (2) the appearance of the upper-level trough at 200 hPa to Sandy's northwest. The low-level WWB and upper-level trough are likely associated with a Madden-Julian Oscillation.

  2. Degraded Ecosystem and its Rehabilitating Measures in Sandy Areas of North China

    Institute of Scientific and Technical Information of China (English)

    ZHANGFengchun; LUQi

    2004-01-01

    Ecosystem degradation occurs in parallel with desertification process in sandy areas of North China. The vast sandy areas in North China are characterized with flexible environments and fragile ecosystems as well as intensive human activities. Due to the annual precipitation gradient decreases from east to west in North China, the whole sandy region falls into 3 main climatic zones: add, semi-add and dry sub-humid zones.The ecosystems in each type of climatic zones are different in climatic conditions, human activities,cultural dimensions, vegetation covers, landscapes, and causes and processes of ecosystem degradation.Therefore, the most effective rehabilitation measures of degraded ecosystems in different types of the climatic zones are also different. For the arid sandy areas, vegetation rehabilitation of degraded ecosystems needs to be completely closed, assisting with artificial measures, such as plantation, irrigation or others. For semi-add sandy areas, the effective measures of vegetation rehabilitation of degraded ecosystems include increasing of proportion of forests and rangelands and limitation of reclamation; reducing the carrying capacity of livestock on unit area of rangelands and growth of fodder plants; and plantation on the lowlands betweens and dunes. For the dry sub-humid areas, the most effective measure is enclosure of degraded ecosystems combined with plantation, and in some cases, just stop uses by grazing or reclamation.

  3. Morphology of Rain Water Channeling in Systematically Varied Model Sandy Soils

    Science.gov (United States)

    Wei, Yuli; Cejas, Cesare M.; Barrois, Rémi; Dreyfus, Rémi; Durian, Douglas J.

    2014-10-01

    We visualize the formation of fingered flow in dry model sandy soils under different rain conditions using a quasi-2D experimental setup and systematically determine the impact of the soil grain diameter and surface wetting properties on the water channeling phenomenon. The model sandy soils we use are random closely packed glass beads with varied diameters and surface treatments. For hydrophilic sandy soils, our experiments show that rain water infiltrates a shallow top layer of soil and creates a horizontal water wetting front that grows downward homogeneously until instabilities occur to form fingered flows. For hydrophobic sandy soils, in contrast, we observe that rain water ponds on the top of the soil surface until the hydraulic pressure is strong enough to overcome the capillary repellency of soil and create narrow water channels that penetrate the soil packing. Varying the raindrop impinging speed has little influence on water channel formation. However, varying the rain rate causes significant changes in the water infiltration depth, water channel width, and water channel separation. At a fixed rain condition, we combine the effects of the grain diameter and surface hydrophobicity into a single parameter and determine its influence on the water infiltration depth, water channel width, and water channel separation. We also demonstrate the efficiency of several soil water improvement methods that relate to the rain water channeling phenomenon, including prewetting sandy soils at different levels before rainfall, modifying soil surface flatness, and applying superabsorbent hydrogel particles as soil modifiers.

  4. The impact of Hurricane Sandy on the mental health of New York area residents.

    Science.gov (United States)

    Schwartz, Rebecca M; Sison, Cristina; Kerath, Samantha M; Murphy, Lisa; Breil, Trista; Sikavi, Daniel; Taioli, Emanuela

    2015-01-01

    To evaluate the long-term psychological impact of Hurricane Sandy on New York residents. Prospective, cross-sectional study. Community-based study. From October 2013 to February 2015, 669 adults in Long Island, Queens, and Staten Island completed a survey on their behavioral and psychological health, demographics, and hurricane impact (ie, exposure). Depression, anxiety, and post-traumatic stress disorder (PTSD). Using multivariable logistic regression models, the relationships between Hurricane Sandy exposure and depression, anxiety, and PTSD were examined. Participants experienced an average of 3.9 exposures to Hurricane Sandy, most of which were related to property damage/loss. Probable depression was reported in 33.4 percent of participants, probable anxiety in 46 percent, and probable PTSD in 21.1 percent. Increased exposure to Hurricane Sandy was significantly associated with a greater likelihood of depression (odds ratio [OR] = 1.09, 95% confidence interval [CI]: 1.04-1.14), anxiety (OR = 1.08, 95% CI: 1.03-1.13), and probable PTSD (OR = 1.32, 95% CI: 1.23-1.40), even after controlling for demographic factors known to increase susceptibility to mental health issues. Individuals affected by Hurricane Sandy reported high levels of mental health issues and were at an increased risk of depression, anxiety, and PTSD in the years following the storm. Recovery and prevention efforts should focus on mental health issues in affected populations.

  5. Optical dating of young tidal sediments in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, A. S.; Andersen, Thorbjørn Joest

    2007-01-01

    reliable and reproducible results in cores from sub-, inter- and supra-tidal sediments, ranging from only a few years up to ~1000 years old, confirming its value in the estimation of estuarine accretion rates. With OSL it is, for the first time, possible to date sediment cores from silty and sandy tidal...... We have tested the applicability of optically stimulated luminescence (OSL) to the dating of young estuarine sediments (dating. The degree of bleaching before deposition...... is investigated by examining the age trend in various sediment cores, and where possible, by comparison with independent age control provided by 210Pb dating. The consistency between optical ages and 210Pb ages is shown to be satisfactory on a time-scale down to only a few years. We conclude that OSL provides...

  6. Understanding and predicting decadal behaviour of sandy barriers

    Science.gov (United States)

    Cooper, Andrew

    2017-04-01

    Developing geological/morphodynamic models of geomorphic systems involves the identification of common attributes from numerous examples or case studies and the distillation away of local variability. Barrier and barrier island systems share many common features, but there is a wide range of variability that strongly influences how they behave at historical timescales. Much morphodynamic modelling is centred on the relationship between dynamic driving forces on the one hand, and geomorphic response on the other. Some models take into account the feedback that exists between these. Less often considered are factors related to sediment volume and supply, underlying geology and the geological setting, and self-organization. Consideration of 'unusual' barrier island systems, where one or more of these factors is particularly important, highlights their role in barrier behaviour. Barrier islands on bedrock in Scotland demonstrate a primary control on evolution of antecedent topography. The low volume of sand in barrier islands in Chesapeake Bay is primarily responsible for very rapid migration rates. Episodic fluvial sediment supply to some South African barriers controls their historical scale behaviour. The high volume of sand in southern Brazil Barriers is a major constraint on their morphological evolution. These and other examples highlight the importance of factors that are often regarded as 'noise' in morphodynamic modelling. The nature of 'local variability' in barriers and barrier islands is diverse, but its important, and even dominant role in their evolution, urges caution in the application of generic modellling approaches in predicting future shoreline behavior.

  7. Sediment characteristics and transportation dynamics of the Ganga River

    Science.gov (United States)

    Singh, Munendra; Singh, Indra Bir; Müller, German

    2007-04-01

    condition attributed to channel competence with low gradient of 70 to 25 cm/km. Coarsening of the bedload sediments in the middle segment of the river develops due to the coarse bedload sediments (mean grainsize: 1.8-2.2 Φ) supply from the tributaries of the northern Indian craton region and increased unit stream power. The Ganga River sediments show a wide range of grainsize parameters [Bedload sediments: mean grainsize (1.5-3.8 Φ), standard deviation (0.3-0.7 Φ), skewness (- 0.2-0.5), and kurtosis (0.8-2.4); suspended load sediments: mean grainsize (2.9-5.0 Φ), standard deviation (0.6-1.6 Φ), skewness (- 0.6-0.4), and kurtosis (0.7-4.6)]. Mean grainsize of the bedload sediments is 2.6 Φ, which is 1.3 Φ units coarser than the suspended load sediments. The cumulative grainsize curves of the bedload sediments show a distinct "break" in slope, representing nearly 80% of the bedload sediment transported as graded suspension. During the peak monsoon discharge, most of the bedload sediments are transported as the discontinuous, fine sandy, graded suspension by the unidirectional unsteady shooting flow at a high transport rate (about 8 × 10 6 tons/d). A model of sedimentation transportation at river channel is proposed. The Ganga River mobilises a total of 729 × 10 6 tons of sediments annually through a narrow zone within its river valley. Under the present hydrogeological conditions, the river sedimentation is climatically controlled and is predicted to produce a 2000-km-long, 2- to 40-km-wide and 25- to 50-m-thick ribbon-shaped, well-sorted symmetrically skewed fine sand body.

  8. How Unique was Hurricane Sandy? Sedimentary Reconstructions of Extreme Flooding from New York Harbor

    Science.gov (United States)

    Brandon, Christine M.; Woodruff, Jonathan D.; Donnelly, Jeffrey P.; Sullivan, Richard M.

    2014-12-01

    The magnitude of flooding in New York City by Hurricane Sandy is commonly believed to be extremely rare, with estimated return periods near or greater than 1000 years. However, the brevity of tide gauge records result in significant uncertainties when estimating the uniqueness of such an event. Here we compare resultant deposition by Hurricane Sandy to earlier storm-induced flood layers in order to extend records of flooding to the city beyond the instrumental dataset. Inversely modeled storm conditions from grain size trends show that a more compact yet more intense hurricane in 1821 CE probably resulted in a similar storm tide and a significantly larger storm surge. Our results indicate the occurrence of additional flood events like Hurricane Sandy in recent centuries, and highlight the inadequacies of the instrumental record in estimating current flood risk by such extreme events.

  9. Sandy desertification trend in western Northeast China Plain in the past 10 years

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The west sandy land of the Northeast China Plain is located in the eastern huge sandy belt of mid-latitude in Eurasia and the eastern fringe of desertified land with best bio-climatic conditions in China. With rapid economic development, the deterioration of eco-environment has occurred and the desertification becomes very obvious. The first part of this paper studies the regional differences of landscape patterns and explores the regional differences of desertification. The second part aims to reveal the dynamics of desertification in the 1990s by using NOAA/AVHRR data and thematic data in GIS database. This work lays a scientific basis for the rehabilitation and development of the sandy lands.

  10. Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil.

    Science.gov (United States)

    Zhuang, Wenhua; Li, Longguo; Liu, Chao

    2013-01-01

    Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%.

  11. The North Atlantic Coast Comprehensive Study and the US Army Corps of Engineers Sandy Recovery Program

    Directory of Open Access Journals (Sweden)

    Henn Roselle

    2016-01-01

    Full Text Available The Disaster Relief Appropriation Act of 2013 (P.L. 113-2 recognized the need to comprehensively evaluate the existing and planned measures to reduce the flooding risk from tidally-influenced storm surges as well as other alternatives for areas at risk to future storm damages. The legislation directed the US Army Corps of Engineers to undertake a Comprehensive Study of the Sandy impacted areas in the North Atlantic Division (Maine to Virginia. This paper reviews the findings and outcomes of the NACCS and their application across the USACE’s Sandy Recovery Program.

  12. Vegetation landscape structure and dynamics in sandy forest-steppe ecotone

    Institute of Scientific and Technical Information of China (English)

    ZOUChun-jing; HANShi-jie; XUWen-duo; LIDao-tang

    2003-01-01

    Sandy forest-steppe ecotone in Baiyinaobao Natural Reserve of Inner Mongolia Autonomous Region of China is one of the special landscape types in forest-steppe vegetation zone in China. Vegetation landscape types, landscape patches and patch size were measured by the field investigation, forest photograph, and airscape. The structure of landscape patches in sandy forest-steppe ecotone, including composition structure, and size structure, was studied and the dynamics and transformation of landscape patches were analyzed. The data obtained in this study could provide theoretical basis for the research on vegetation landscape in forest-steppe ecotones and other vegetation types.

  13. Propagation of Rayleigh waves in anisotropic layer overlying a semi-infinite sandy medium

    Directory of Open Access Journals (Sweden)

    P.C. Pal

    2015-06-01

    Full Text Available The present investigation deals with the propagation of Rayleigh waves in anisotropic layer overlying a sandy medium. Anisotropic material is in the nature of most general case i.e. of triclinic crystal and sandy medium is of alluvial soil type. The solutions for layer and half-space are obtained analytically. The displacement components in x and z directions are obtained for both the media. The dispersion relation is obtained subjected to certain boundary conditions. The special cases are considered. The numerical results are presented in the form of wave number and phase velocity (k − c analytical curves.

  14. Draft Detailed Project Report and Environmental Assessment, Sandy Point Navigation Channel, Whatcom County, Washington.

    Science.gov (United States)

    1984-11-01

    ment. Maurice L. Schwartz, of Coastal Consultants, Inc., provided a report on shoaling at Sandy Point which was also used in developing this...8217 BS SOFT TO VERY A. SFT. LACO [...j L RAVEL C0%TACT SUR- TORVAYAE.BOOPSF FIT ORGANIC SILT £PEAT IN LAYE RS, VERY CT LL:RA BLACK * ~~ VE ASN PL 44...Schwartz, Maurice L. 1983. Marina inlet shoaling at Sandy Point, Washington. Submitted to Seattle District, U.S. Amy Corps of Engineers. U.S. Fish and

  15. Influence of bioturbation on sediment respiration in advection- and diffusion-dominated systems

    Science.gov (United States)

    Baranov, Viktor; Krause, Stefan; Lewandowski, Jörg

    2017-04-01

    Ecosystem engineers are organisms, whose impact on ecosystem functioning is large compared to their abundance and biomass. Classic examples of ecosystem engineers are burrowing organisms whose activity is affecting the sediment matrix and pore solutes in aquatic sediments; this is called bioturbation. Constant reworking of the sediment matrix and transport of solutes caused by activities of sediment-dwelling organisms are modifying habitats and resource availability. Despite that progress of studies on the interactions between the animal bioturbation and the sediment respiration was rather slow, mostly due to the existing methodological limitations. Conceptual framework, formulated by Mermelloid-Blondin and Rosenberg (2006) is suggesting that impact of bioturbation on the sediment biogeochemistry will be much larger in sediments with low hydraulic conductivities (diffusion-dominated) than in sediments with high hydraulic conductivities (advection-dominated). In order to test this hypothesis in application to the sediment respiration, we have used the resazurin-resorufin bioreactive tracer system, which allowed us to decouple respiration of the sediment of microbiota. Our work has shown that in diffusion-dominated sediments (organic rich lake sediments) bioturbator's (bloodworms, larvae of Diptera, Chironomidae) activity could increase sediment aerobic respiration by 300%. In addition to that, impact of the bioturbators on the diffusion-dominated sediments respiration is growing with increasing temperature. Total oxygen consumption (TOU) in such sediments is also increasing by about 50% in bioturbated sediments in comparison with uninhabited sediments. On the other hand, in advection-dominated sediments (sandy sediments from marine tidal flats, bioturbated by brittlestars) we have observed no increase in TOU, and only slight (25%) increase in aerobic respiration in the presence of bioturbators. It became evident that due to the high hydraulic conductivity of

  16. Multi-level assessment of chronic toxicity of estuarine sediments with the amphipod Gammarus locusta: II. Organism and population-level endpoints.

    Science.gov (United States)

    Costa, Filipe O; Neuparth, Teresa; Correia, Ana D; Costa, Maria Helena

    2005-07-01

    This study aimed to test the performance of the amphipod Gammarus locusta (L.) in chronic sediment toxicity tests. It constitutes part of a multi-level assessment of chronic toxicity of estuarine sediments, integrating organism and population-level endpoints with biochemical markers responses. Here we account for organism and population-level effects, while biomarker responses were reported in a companion article. Five moderately contaminated sediments from Sado and Tagus estuaries were tested, comprising 3 muddy and 2 sandy sediments. These sediments either did not show acute toxicity or were diluted with control sediment as much as required to remove acute toxicity. Subsequent chronic tests consisted of 28-day exposures with survival, individual growth and reproductive traits as endpoints. Two of the muddy sediments induced higher growth rates in the amphipods, and improved reproductive traits. This was understood to be a consequence of the amount of organic matter in the sediment, which was nutritionally beneficial to the amphipods, while concurrently decreasing contaminant bioavailability. Biomarker responses did not reveal toxicant-induced stress in amphipods exposed to these sediments. One of the sandy sediments was acutely toxic at 50% dilution, but in contrast stimulated amphipod growth when diluted 75%. This was presumed to be an indication of a hormetic response. Finally the two remaining contaminated sediments showed pronounced chronic toxicity, affecting survival and reproduction. The sex ratio of survivors was highly biased towards females, and offspring production was severely impaired. The particulars of the responses of this amphipod were examined, as well as strengths versus limitations of the sediment test. This study illustrates the utility of this chronic test for toxicity assessment of contaminated estuarine sediments, with potential application all along Atlantic Europe.

  17. [Distribution and seasonal dynamics of meiofauna in intertidal zone of Qingdao sandy beaches, Shandong Province of East China].

    Science.gov (United States)

    Li, Ha; Hua, Er; Zhang, Zhi-Nan

    2012-12-01

    An investigation was conducted on the abundance, group composition, and distribution of meiofauna at the Second Beach of Taiping Bay and the Shilaoren Beach in Qingdao in January, April, July, and October 2008, aimed to analyze the distribution and seasonal dynamics of meiofauna in the intertidal zone of Qingdao sandy beaches. The measurements of environmental factors, including sediment grain size, interstitial water salinity, interstitial water temperature, organic matter content (TOC), and chlorophyll a (Chl a) content, were made simultaneously. There existed obvious seasonal differences in the environment factors, which could be clustered into two groups, i. e. , spring-winter group (January and April) and summer-autumn group (July and October). At the Second Beach of Taiping Bay, the mean annual abundance of meiofauna was (1167.3 +/- 768.3) ind x 10 cm(-2), and the most dominant group was Nematoda, accounting for 91% of the total. The meiofaunal group composition and abundance at the Second Beach differed horizontally, with the abundance ranked as high tide zone high values in spring/winter and low values in summer/autumn (spring > winter > autumn > summer). The vertical distribution of the meiofauna in the high and middle tide zones of the Second Beach varied seasonally too. The meiofauna migrated downward with increasing temperature, concentrated in surface layer in winter and migrated downward in summer. At the Shilaoren Beach, the mean annual abundance of meiofauna was (1130.2 +/- 1419.1) ind x 10 cm(-2), and Nematoda accounted for 85% of the total. There was a great similarity of the environmental factors in the middle tide zone of the Second Beach and Shilaoren Beach, which led to no differences in the meiofaunal group composition and abundance. However, the vertical distribution of the meiofauna differed between the two beaches. When the temperature decreased, the meiofauna at Shilaoren Beach migrated downward. The ANOVA and BIOENV analyses showed that

  18. Experiments on the movement of pesticides in sandy soils to groundwater : prospects of testing preferential transport models

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2012-01-01

    Many agricultural areas with humic-sandy and loamy-sandy soils are used also for the extraction of water for drinking-water supply. Model concepts have been developed for the fast preferential transport of plant protection products (pesticides) in such soils, e.g. by fingered and funneled flow. An i

  19. 78 FR 12109 - Order Extending Temporary Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy

    Science.gov (United States)

    2013-02-21

    ... seq. \\2\\ Order Granting Exemptions from Certain Rules of Regulation SHO Related to Hurricane Sandy... Hurricane Sandy made landfall and whose settlement depends on the delivery of such physical certificates (or... COMMISSION Order Extending Temporary Exemptions From Certain Rules of Regulation SHO Related to...

  20. Maize productivity and mineral N dynamics following different soil fertility management practices on a depleted sandy soil in Zimbabwe

    NARCIS (Netherlands)

    Chikowo, R.; Mapfumo, P.; Nyamugafata, P.; Giller, K.E.

    2004-01-01

    There is a need for an improved understanding of nitrogen (N) dynamics in depleted sandy soils in southern Africa. A field experiment was conducted to evaluate the performance of different soil fertility improvement practices on a degraded granitic sandy soil in Zimbabwe. Legumes capable of accumula

  1. 33 CFR 334.102 - Sandy Hook Bay, Naval Weapons Station EARLE, Piers and Terminal Channel, restricted area...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Sandy Hook Bay, Naval Weapons... DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.102 Sandy Hook Bay, Naval Weapons Station EARLE, Piers..., shall be enforced by the Commanding Officer, Naval Weapons Station Earle, and/or other persons or...

  2. Study of Sediments in the Yutian-Hotan Oasis,South Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on investigation of sediments in the Yutian-Hotan Oasis at the southern margin of the Tarim basin, 14C ages and grain-size and chemical element analyses, the following views are put forward in this paper.(1) Sediments in the Yutian-Hotan Oasis are composed chiefly of "oasis soil", similar to the recent oasis soil, i.e. brown desert soil, which was formed due to pedogenesis after aeolian sand (sandy loam) and dust (loess) of 3.32-6.64 j were deposited.(2) The ancient Yutian-Hotan Oasis represented by oasis soil was formed at 13000 a B.P. During the cold period of the past 13000 years, this region is characterized mainly by accumulation of sand and dust storms, and sandy oasis soil was developed in this region due to pedogenesis in an oasis environment; during the warm period, dust falls predominated along with certain current concomitants (lacustrine facies), and silty oasis soil was formed by pedogenesis. Owing to fluctuations of cold and warm climates since 13000 a B.P., sandy oasis soil was deposited alternately with silty oasis soil and lacustrine soils. Nevertheless, the Yutian-Hotan Oasis has been preserved and developing continuously towards the contemporary time.(3) At the latest, the oasis became an important site of human inhabitancy at 10000 a B.P., and since then it has been an important base for the propagation and activity of local people in the Tarim Basin.

  3. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  4. National Geochemical Database: Sediment

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical analysis of sediment samples from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are of stream sediment in...

  5. Indicators: Sediment Enzymes

    Science.gov (United States)

    Sediment enzymes are proteins that are produced by microorganisms living in the sediment or soil. They are indicators of key ecosystem processes and can help determine which nutrients are affecting the biological community of a waterbody.

  6. National Geochemical Database: Sediment

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical analysis of sediment samples from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are of stream sediment...

  7. Center for Contaminated Sediments

    Data.gov (United States)

    Federal Laboratory Consortium — The U.S. Army Corps of Engineers Center for Contaminated Sediments serves as a clearinghouse for technology and expertise concerned with contaminated sediments. The...

  8. Evaluation of sediment sampling devices and methods used in the NKS/EKO-1 project

    Energy Technology Data Exchange (ETDEWEB)

    Ilus, E. [Finnish Centre for Radiation and Nuclear Safety (Finland)

    1996-10-01

    The radioactive fallout caused by nuclear weapons tests in the 1960s and the accident at the Chernobyl NPP in 1986 has created useful markers in the sediments of many Nordic waters. These have been successfully used not only in radioecological studies but also in limnological and marine research dealing with sedimentation processes and rates. To be able to study sedimentation and processes in sediments, it is essential to obtain reliable samples from sediments. False conclusions are an obvious risk if the studies are based on biased field samples. More strictly,, it is unreasonable to perform exacting and expensive analyses if the samples themselves are unreliable or of poor quality. The instruments best suited for quantitative sampling of soft-bottom sediments appear to be those based on the coring principle. Box corers can be reliably used for bulk sampling of coherent sediments and some silty and sandy sediments. Many factors speak in favour of large diameters/areas of the corer orifices. It is not possible, however, to increase the tube diameter without negative impact to the corer`s handiness and increasing difficulty in handling and slicing of the cores. Despite the large variety of sampling instruments and many sources of error involved in the use of different instruments, it is most important to know and account for the disadvantages and to work as carefully as possible towards minimizing errors and obtaining undisturbed, reliable samples. (EG).

  9. Baculovirus Host-Range

    Institute of Scientific and Technical Information of China (English)

    Suzanne M. Thiem; Xiao-Wen Cheng

    2009-01-01

    Baculoviruses are used as microbial insecticides, protein expression vectors, epitope display platforms, and most recently as vectors for gene therapy. Understanding the mechanisms that control baculovirus host-range and tissue tropisms are important for assessing their safety and for improving their properties for these biotechnology applications. In the past two decades some progress has been made and several baculovirus genes that influence host-range have been identified. Despite this progress, our understanding of the underlying mechanisms that restrict baculovirus host-range is still limited. Here we review what is currently known about baculovirus genes that influence virus host-range.

  10. Quantifying biologically and physically induced flow and tracer dynamics in permeable sediments

    Directory of Open Access Journals (Sweden)

    F. J. R. Meysman

    2007-08-01

    Full Text Available Insight in the biogeochemistry and ecology of sandy sediments crucially depends on a quantitative description of pore water flow and the associated transport of various solutes and particles. We show that widely different problems can be modelled by the same flow and tracer equations. The principal difference between model applications concerns the geometry of the sediment-water interface and the pressure conditions that are specified along this boundary. We illustrate this commonality with four different case studies. These include biologically and physically induced pore water flows, as well as simplified laboratory set-ups versus more complex field-like conditions: [1] lugworm bio-irrigation in laboratory set-up, [2] interaction of bio-irrigation and groundwater seepage on a tidal flat, [3] pore water flow induced by rotational stirring in benthic chambers, and [4] pore water flow induced by unidirectional flow over a ripple sequence. The same two example simulations are performed in all four cases: (a the time-dependent spreading of an inert tracer in the pore water, and (b the computation of the steady-state distribution of oxygen in the sediment. Overall, our model comparison indicates that model development for sandy sediments is promising, but within an early stage. Clear challenges remain in terms of model development, model validation, and model implementation.

  11. Electrodialytic remediation of sediments

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland

    often hinders this usage. Hence, for both types of sediments, expensive deposition at hazardous waste landfills is required. Electrodialysis is presently being developed as an alternative method for treatment of such contaminated sediments. Heavy metals are removed by treating the sediments...

  12. Sediment Sources and Transport Pathway Identification Based on Grain-Size Distributions on the SW Coast of Portugal

    Directory of Open Access Journals (Sweden)

    Xiaoqin Du

    2015-01-01

    Full Text Available Espichel-Sines is an embayed coast in SW Portugal, consisting of two capes at both extremities, a tidal inlet and associated ebb tidal delta, a barrier spit, sandy beaches, sea cliffs, and a submarine canyon. Beach berm, backshore, near shore and inner shelf sediment samples were taken. Samples were analyzed for their grain-size compositions. This study ranks the hypothetical sediment sources influences on the sediment distributions in the study area using the multivariate Empirical Orthogonal Function (EOF techniques. Transport pathways in this study were independently identified using the grain size trend analysis (GSTA technique to verify the EOF findings. The results show that the cliff-erosion sediment is composed of pebbles and sand and is the most important sediment source for the entire embayment. The sediment at the inlet mouth is a mixture of pebbles, sand, silt, and clay, which is a minor sediment source that only has local influence. The overall grain-size distributions on the shelf are dominated by the sand except for the high mud content around the tidal delta front in the northern embayment. Sediment transport patterns on the inner shelf at the landward and north sides of the canyon head are landward and northward along the barrier spit, respectively. On the south side of the canyon head, the prevailing sediment transport is seaward. Sediment transport occurs in both directions along the shore.

  13. Using a sediment budget to understand geomorphic response following dam removal

    Science.gov (United States)

    Major, J. J.; O'Connor, J. E.; Podolak, C.; Keith, M.; Spicer, K.; Pittman, S.; Bragg, H.; Wallick, J.; Grant, G.

    2013-12-01

    Dam removal provides an exceptional setting for developing tightly constrained sediment budgets linking reservoir erosion with downstream deposition. Measurements of erosion of impounded sediment can provide precise values on sediment input, and measurements of downstream flux and deposition provide potentially well-constrained estimates of output and storage. Measurements of sediment erosion, flux, deposition, and composition following the 2007 breaching of Marmot Dam, Oregon, allowed construction of size-fraction sediment budgets for the first year following dam removal, which documented the spatial distributions and fluxes of nearly 400,000 m3 of sand and gravel released from the former reservoir. The budget encompassed a ~25-km-long control-volume-reach of the Sandy River extending from about 10 km upstream of the dam site to about 15 km downstream. Budget components consisted of measurements of sediment flux into the reservoir reach, erosion from the reservoir reach, sediment flux and deposition along a 2-km-long reach immediately downstream of the dam site before the river entered a 7-km-long bedrock gorge, and sediment flux out of the gorge. Our results show that channel morphology strongly filtered the flux and distribution of released sediment. About 70-90 percent of the gravel released by reservoir erosion deposited within 2 km of the dam site, whereas sand largely passed into and through the bedrock gorge. Flux measurements ~8 km beyond the gorge exit indicate that about half the sand load that emerged from the gorge deposited in the intervening 8-km channel reach. Combining flux measurements with volumetric measurements of erosion and deposition greatly aided construction and interpretation of the sediment budget. Despite the immense effort exerted to measure sediment erosion (relatively easy; cost effective), flux (very challenging; expensive), and deposition (relatively easy above gorge; cost effective), and the tight spatial distributions of the

  14. Sulfur cycling of intertidal Wadden Sea sediments (Konigshafen, Island of Sylt, Germany): sulfate reduction and sulfur gas emission

    Science.gov (United States)

    Kristensen, E.; Bodenbender, J.; Jensen, M. H.; Rennenberg, H.; Jensen, K. M.

    2000-05-01

    Sulfate reduction rates (SRR t) and reduced inorganic sulfur pools (RIS) in Wadden Sea sediment as well as sulfur gas emissions directly to the atmosphere were measured at intervals of 2 to 12 months from 1991 to 1994. Three stations were chosen in the intertidal embayment, Königshafen, representing the range of sediments found in the Wadden Sea: Organic-poor coarse sand, organic-poor and Arenicola marina inhabited medium sand, and organic-rich muddy sand. Maximum SRR t were 2 to 5 times higher in muddy sand than in the sandy sediments. The depth-integrated SRR t varied 12 to 13-fold on a seasonal basis at the three stations. Although temperature controls biochemical processes, the overall control is more complex due to the simultaneous influence of other seasonal factors such as availability of organic matter and oxidation level of surface sediment. The sedimentary RIS pools were low due to iron limitation and contained only 30% acid volatile sulfur (AVS). Muddy sand had up to an order of magnitude more RIS than the two sandy sediments. The turnover of RIS was rapid (turnover time from ˜1 to 32 h), fastest during summer and at the sandy stations. The emission of S-gases was dominated by H 2S during summer (45-67% of the total), and was highest in muddy and lowest in coarse sand. H 2S was less important in early spring (3-49% of the total). Other sulfur gases, such as COS, DMS and CS 2, each accounted for less than 20% of the total sulfur emissions with no specific temporal and spatial pattern. Due to the low content of metals in the sediment, the reduced sulfur pools are cycled rapidly with chemical and biological reoxidation at oxic-anoxic boundaries as a major sink. Thus, the emissions of H 2S account for less than 1‰ of the sulfide produced.

  15. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...

  16. Lessons from Hurricane Sandy: a community response in Brooklyn, New York.

    Science.gov (United States)

    Schmeltz, Michael T; González, Sonia K; Fuentes, Liza; Kwan, Amy; Ortega-Williams, Anna; Cowan, Lisa Pilar

    2013-10-01

    The frequency and intensity of extreme weather events have increased in recent decades; one example is Hurricane Sandy. If the frequency and severity continue or increase, adaptation and mitigation efforts are needed to protect vulnerable populations and improve daily life under changed weather conditions. This field report examines the devastation due to Hurricane Sandy experienced in Red Hook, Brooklyn, New York, a neighborhood consisting of geographically isolated low-lying commercial and residential units, with a concentration of low-income housing, and disproportionate rates of poverty and poor health outcomes largely experienced by Black and Latino residents. Multiple sources of data were reviewed, including street canvasses, governmental reports, community flyers, and meeting transcripts, as well as firsthand observations by a local nonprofit Red Hook Initiative (RHI) and community members, and social media accounts of the effects of Sandy and the response to daily needs. These data are considered within existing theory, evidence, and practice on protecting public health during extreme weather events. Firsthand observations show that a community-based organization in Red Hook, RHI, was at the center of the response to disaster relief, despite the lack of staff training in response to events such as Hurricane Sandy. Review of these data underscores that adaptation and response to climate change and likely resultant extreme weather is a dynamic process requiring an official coordinated governmental response along with on-the-ground volunteer community responders.

  17. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  18. Weathering the Superstorm: From Texts to Twitter--How Campus Communicators Overcame Hurricane Sandy

    Science.gov (United States)

    Towns, Gail

    2013-01-01

    By the time Superstorm Sandy struck New Jersey in late October 2012, Kathy Corbalis, executive director of communications and college relations at Atlantic Cape Community College, and her team were battle-tested. In the 15 months before the hurricane, the college experienced two bomb threats via Twitter, a lockdown due to gunfire, an on-campus…

  19. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.

    2015-01-01

    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the ero

  20. 2012 USACE Post Sandy Topographic LiDAR: Virginia and Maryland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: VIRGINIA AND MARYLAND LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X2314841 Woolpert Project...

  1. Solute leaching in a sandy soil with a water-repellent surface layer: a simulation.

    NARCIS (Netherlands)

    Rooij, de G.H.; Vries, de P.

    1996-01-01

    Many sandy soils in the Netherlands have a water-repellent surface layer covering a wettable soil with a shallow groundwater table. Fingers form in the water-repellent surface layer and rapidly transport water and solutes to the wettable soil in which the streamlines diverge. Although several field

  2. Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

    2015-01-01

    for each rotation: mouldboard ploughing to a depth of 20 cm (MP); harrowing to a depth of 8–10 cm (H); and direct drilling (D) at two experimental sites with a sandy loam soil and different water budgets in Denmark. The Muencheberg soil quality rating (M-SQR) method and simpler soil quality indices (i...

  3. Modeling the growth and migration of sandy shoals on ebb-tidal deltas

    NARCIS (Netherlands)

    Ridderinkhof, W.; de Swart, H. E.; van der Vegt, M.; Hoekstra, P.

    2016-01-01

    Coherent sandy shoals that migrate toward the downdrift coast are observed on many ebb-tidal deltas. In this study, processes that cause the growth and migration of shoals on ebb-tidal deltas are identified. Moreover, the effect of the incident wave energy and the tidal prism of an inlet on the migr

  4. Trends in soil organic matter contents in Dutch grasslands and maize fields on sandy soils

    NARCIS (Netherlands)

    Hanegraaf, M.C.; Hoffland, E.; Kuikman, P.J.; Brussaard, L.

    2009-01-01

    There is considerable concern in Europe that soil organic matter (SOM) contents are declining, which would threaten both agriculture and the environment. We performed a trend analysis of SOM contents in sandy soils, using historic data from routine agricultural soil analyses. Data were selected from

  5. Experimental study on stability of sunken large diameter cylindrical structure on sandy seabed during construction period

    Institute of Scientific and Technical Information of China (English)

    秦崇仁; 庞红犁; 李世森; 张伟

    2002-01-01

    A systematic experimental research work is done for the stability of sunken large diameter cylinder during construction period. It is the first research that gives the method for assessing the stability of the larger diameter cylindrical structure, a set of values is derived also for the critical stability indices of the large diameter cylinder sunken to the sandy seabed.

  6. Toward a Unified Military Response: Hurricane Sandy and the Dual Status Commander

    Science.gov (United States)

    2015-04-01

    Ozzie Paez, “Emergency Managers’ Views on Improving Defense Support/ Military Assistance to Civil Authorities (DSCA/MACA) Educa - tion Programs...contrary, in fact. The prob- 74 lems that occurred during the Sandy response in most cases can be attributed largely to lack of formal educa - tion

  7. TOXICITY TRENDS DURING AN OIL SPILL BIOREMEDIATION EXPERIMENT ON A SANDY SHORELINE IN DELAWARE, USA

    Science.gov (United States)

    A 13-week, refereed, inter-agency toxicity testing program involving five bioassay methods was used to document the effectiveness of shoreline bioremediation to accelerate toxicity reduction of an oiled sandy shoreline at Fowler Beach, Delaware, USA. The study was part of an inte...

  8. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

    Science.gov (United States)

    Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

  9. Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China

    Science.gov (United States)

    Feng-Rui Li; Zhi-Yu Zhou; Li-Ya Zhao; Ai-Sheng Zhang; Ling-Fen Kang

    2007-01-01

    This study investigated the abundance and frequency of occurrence of all shrub species present in the standing vegetation at four sites, including a 5-year exclosure (protected grassland) and three adjacent unprotected grazing sites that had been subjected to different levels of degradation (light, moderate and severe), in xeric sandy grassland of Inner Mongolia for...

  10. State of the art of the meiofauna of Brazilian Sandy Beaches

    Directory of Open Access Journals (Sweden)

    Tatiana Fabricio Maria

    Full Text Available Abstract In Brazil, meiofauna studies began in the middle of last century, but they adopted a purely taxonomical approach, describing species from various zoological groups. After this first step, this benthic group was largely neglected until the end of the 20th century when ecological studies began. We here provide a brief review of present knowledge of the meiofauna found on Brazilian sandy beaches to provide information for ReBentos (Coastal Benthic Habitats Monitoring Network. Our methodology consisted of a bibliographic survey undertaken using different datasets (Web of ScienceTM, SCOPUS, Google Scholar and Lattes Plataform. For the survey, we considered only those studies published till early 2015. Our analysis showed that the number of meiofauna studies has increased over the last two decades, though they are mainly still concentrated on the Southeast of Brazil. These studies aim to explain the distribution pattern of the meiofauna of the intertidal region of sandy beaches. Based on the results, we presented a discussion of three main topics, i.e., (a current knowledge of Brazilian sandy beach meiofauna, (b sampling strategies for monitoring of the meiofauna, and (c use of the meiofauna as a tool to assess climate change. We trust that this brief review will be useful as a starting point for the delineation of further climate change investigations into sandy beach meiofauna.

  11. 2012 USACE Post-Hurricane Sandy Topographic LiDAR: Eastern Long Island, New York

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: EASTERN LONG ISLAND, NEW YORK LIDAR ACQUISITION FOR HURRICANE SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X23208588...

  12. Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged HUmic-Sandy Soil

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. R

  13. Improvement of Water Movement in an Undulating Sandy Soil Prone to Water Repellency

    NARCIS (Netherlands)

    Oostindie, K.; Dekker, L.W.; Wesseling, J.G.; Ritsema, C.J.

    2011-01-01

    The temporal dynamics of water repellency in soils strongly influence water flow. We investigated the variability of soil water content in a slight slope on a sandy fairway exhibiting water-repellent behavior. A time domain reflectometry (TDR) array of 60 probes measured water contents at 3-h

  14. Effects of Carboxymethylcelluloses (CMC) on Some Hydraulic Properties of Sandy Soil

    Institute of Scientific and Technical Information of China (English)

    ANDRY Henintsoa; INOUE Mitsuhiro; MORITANI Shigeoki; UZOMA Kingsley Chinyere

    2010-01-01

    The property of hydrophilic polymers capable absorbing huge volumes of water led to many practical applications of these new materials in arid regions for improving the water retention in sandy soils. Effects of four carboxymethylcelluloses (CMC), mixed at various rates with the sandy soil, on the water-holding capacity and hydraulic conductivity (Ks) when leached with distilled water (simulating rain), tap water, and saline water were evaluated. The maximum water absorption of CMCs ranged between 80 and 100 kg. kg-1 of polymer; however, the absorbent swelling capacity decreased significantly with increasing the salt concentration in the solution. The water absorption capacity of CMCs decreased significantly when incorporated in the sandy soil compared to that of the absorbent alone. Application of CMC increased significantly the available water content up to 3 ±0.5 times. All soils treated with CMCs showed a significant lower in Ks compared to the control soil. Meanwhile, Ks was found increased with increasing the salt concentration in the leaching solution. This understanding of characteristics of the absorbents and the interactions among absorbents, soil, and irrigation water quality would be of help in water management of sandy soil.

  15. Rain water transport and storage in a model sandy soil with hydrogel particle additives.

    Science.gov (United States)

    Wei, Y; Durian, D J

    2014-10-01

    We study rain water infiltration and drainage in a dry model sandy soil with superabsorbent hydrogel particle additives by measuring the mass of retained water for non-ponding rainfall using a self-built 3D laboratory set-up. In the pure model sandy soil, the retained water curve measurements indicate that instead of a stable horizontal wetting front that grows downward uniformly, a narrow fingered flow forms under the top layer of water-saturated soil. This rain water channelization phenomenon not only further reduces the available rain water in the plant root zone, but also affects the efficiency of soil additives, such as superabsorbent hydrogel particles. Our studies show that the shape of the retained water curve for a soil packing with hydrogel particle additives strongly depends on the location and the concentration of the hydrogel particles in the model sandy soil. By carefully choosing the particle size and distribution methods, we may use the swollen hydrogel particles to modify the soil pore structure, to clog or extend the water channels in sandy soils, or to build water reservoirs in the plant root zone.

  16. 2012 USACE Post Hurricane Sandy Topographic LiDAR: Virginia and Maryland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: VIRGINIA AND MARYLAND LIDAR ACQUISITION FOR HURRICANE SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X2314841 Woolpert...

  17. Effects of DCD addition to slurry on nitrate leaching in sandy soils

    NARCIS (Netherlands)

    Corré, W.J.; Zwart, K.B.

    1995-01-01

    The effects of the addition of the nitrification inhibitor dicyandiamide (DCD) to cattle slurry, applied in autumn to an arable sandy soil, were investigated in a three-year field experiment in the Netherlands. Treatments included application of slurry with DCD in November and December, application

  18. Contribution of individual sorbents to the control of heavy metal activity in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    A multisurface model is used to evaluate the contribution of various sorption surfaces to the control of heavy metal activity in sandy soil samples at pH 3.7-6.1 with different sorbent contents. This multisurface model considers soil as a set of independent sorption surfaces, i.e. organic matter (NI

  19. Factors affecting N immobilisation/mineralisation kinetics for cellulose-, glucose- and straw-amended sandy soils

    NARCIS (Netherlands)

    Vinten, A.J.A.; Whitmore, A.P.; Bloem, J.; Howard, R.; Wright, F.

    2002-01-01

    The kinetics of nitrogen immobilization/mineralization for cellulose-, glucose- and straw-amended sandy soils were investigated in a series of laboratory incubations. Three Scottish soils expected to exhibit a range of biological activity were used: aloamy sand, intensively cropped horticultural soi

  20. Evaluation of a LIDAR Land-Based Mobile Mapping System for Monitoring Sandy Coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.

    2011-01-01

    The Dutch coast is characterized by sandy beaches flanked by dunes. Understanding the morphology of the coast is essential for defense against flooding of the hinterland. Because most dramatic changes of the beach and the first dune row happen during storms, it is important to assess the state of th

  1. Evaluation of a laser land-based mobile mapping system for monitoring sandy coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.

    2010-01-01

    The Dutch coast is characterized by sandy beaches flanked by dunes. Its morphology is essential for the defense against flooding of the hinterland. Therefore it is monitored on a yearly basis by Airborne Laser Scanning (ALS). However, it is recognized that most erosion of the beach and first dune ro

  2. Irrigation and nitrogen use efficiency of Thuja occidentalis grown on sandy soils

    NARCIS (Netherlands)

    Pronk, A.A.

    2004-01-01

    A combined conifer growth - soil water and nitrogen balance model was calibrated to simulate dry mass production and partitioning, water and nitrogen demand and nitrogen losses for Thuja occidentalis grown for two years on a sandy soil. Light interception was successfully described by the row-of-cub

  3. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  4. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.

    2015-01-01

    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the

  5. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

    2001-01-01

    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium....

  6. Transport of water and solutes in wettable and water repellent sandy soils

    NARCIS (Netherlands)

    Ritsema, C.J.; Dekker, L.W.

    1996-01-01

    The research yielded the following conclusions and results: preferential flow can be expected in recently deposited, loosely packed, wettable dune sands; preferential flow is common in most water-repellent sandy soils; distribution flow in topsoils isa process of major importance, resulting in a

  7. Meiofauna communities in exposed sandy beaches on the Galician coast (NW Spain, six months after the Prestige oil spill: the role of polycyclic aromatic hydrocarbons (PAHs

    Directory of Open Access Journals (Sweden)

    Puri Veiga

    2010-04-01

    Full Text Available The effect of polycyclic aromatic hydrocarbons (PAHs on Galician sandy beach ecosystems, six months after the Prestige oil spill, was evaluated using the meiobenthos at a higher taxon level as an indicator. Meiobenthos community structure, environmental variables and sediment PAH content from six affected exposed beaches were studied and compared with three reference sites. They were also compared with data from polluted beaches obtained during the first days of the spill. Significant amounts of PAHs were found in affected beach sediments and both univariate and multivariate analyses showed differences between affected and reference beaches. Correlation analyses between PAH content and the meiobenthos community structure showed that 1,2-dimethylnaphthalene (C2-NAPH and 1-methylphenanthrene (C-PHEN affected both the community structure and the abundance of the main taxa. These two PAHs seem to be responsible for the low meiofauna density values, which suggests that there is a relationship between the oil spill and the differences between affected and reference localities.

  8. Assessing the relative role of climate change and human activities in sandy desertification of Ordos region,China

    Institute of Scientific and Technical Information of China (English)

    XU DuanYang; KANG XiangWu; LIU ZhiLi; ZHUANG DaFang; PAN JianJun

    2009-01-01

    Climate change and human activities are driving forces of sandy desertification and the relative role of them in sandy desertification is the hot point in related researches.A study was carried to assess the relative role of climate change and human activities in sandy desertification of Ordos region in China.Potential NPP and the difference between potential and actual NPP were selected as indicators to as-sess the relative role of climate change and human activities in sandy desertification,respectively.Assessing methods were built based on some scenarios for the reversion and expansion of sandy desertification and the relative role of climate change and human activities in sandy desertification of Ordos region were assessed from 1981 to 2000.The results showed that although some local places experienced an expansion of sandy desertification,the change of sandy desertification of Ordos region from 1981 to 2000 showed a stably reversing trend.The relative role of climate change and human ac-tivities in sandy desertification of Ordos region varied at different temporal and spatial scales in the reversion and expansion processes.In the reversion of sandy desertification,climate change was the dominant factor in the period of 1981 to 1990 and the reversed areas mainly induced by climate change including Mu Us sandy land and the transition zone between temperate steppe and temperate decidu-ous scrubs in north east of Ordos region; however,human activities controlled the reversed process during the period from 1991 to 2000 and the areas mainly induced by human activities distributed in all banners of Ordos region.In the expansion of sandy desertificallon,human activities were the dominant factor in the period of 1981 to 1990 and the expanded areas mainly included the regions around com-mon boundary of Hanggin,Dalad Banners and Dongsheng City; however,climate change dominated the expansion of sandy desertification from 1991 to 2000,the expanded areas equably distributed

  9. Preliminary reconstruction of the desert and sandy land distributions in China since the last interglacial period

    Institute of Scientific and Technical Information of China (English)

    CHEN; Huizhong; SU; Zhizhu; YANG; Ping; DONG; Guangrong

    2004-01-01

    The desert and sandy land are the products of arid climate. The spatial distribution of modern deserts and sandy land in China and their relation to climate show following characteristics: arid and hyper-arid desert zones, at isohyet of less than 200 mm, are dominated by mobile dunes; semi-arid steppe and arid desert steppe with the precipitation between 200-400mm, are dominated by semi-fixed and fixed sand dunes; the precipitation of sub-humid forest grassland and humid forest zones with scattered fixed sand land is higher than 400 mm. With this as reference, in combination with considerable amount of paleoclimatic data in desert regions and adjacent regions, the distributions of desert and sandy land in China during the last interglacial period, the last glacial maximum (LGM), and the Holocene megathermal, were preliminarily reconstructed. The results compared with that of today show that the distribution of desert and sandy land in China was greatly dwindled during last interglacial period, and the mobile dune area was about two-thirds of that of today's, but greatly expanded during LGM. However, the dwindling area of desert and sandy land in the Holocene megathermal was smaller than that in the last interglacial period. The forcing mechanism was mainly related to the changes of East Asian winter and summer monsoon, south-northward swing of the westerlies and the variations of the Qinghai-Tibet Plateau monsoon intensity caused by global climate changes during the cold and warm intervals since the last interglacial period.

  10. Resource utilization and trophic niche width in sandy beach macrobenthos from an oligotrophic coast

    Science.gov (United States)

    Ortega-Cisneros, Kelly; de Lecea, Ander M.; Smit, Albertus J.; Schoeman, David S.

    2017-01-01

    One of the paradigms underlying sandy beach ecology is the overriding control by physical processes; thus, biological interactions (i.e. food availability, competition and predation) are believed to play a role structuring macrofaunal communities only in benign habitats such as dissipative beaches. Moreover, sandy beaches are characterized by low in-situ productivity, so their food webs rely heavily on marine inputs. Studies have shown that estuarine organic matter plays a key role in influencing the dynamics of marine ecosystems. However, very few studies have tested the role of estuarine input on sandy beaches. Here, we aim to determine the impact of estuarine input on the food web of a sandy beach macrobenthic community. To this end, particulate organic matter (POM) samples from the marine environment and the estuary, as well as macrobenthic samples from the beach, were analysed for their stable isotope (SI) signature. Our results indicated that the POM SI signatures were not different along the beach, but differences were recorded between marine and estuarine sources. Bayesian mixing models indicated that the organisms did not make use of the estuarine POM at the beginning of the wet season, but relied more heavily on this resource towards the end of the wet season. This leads to the conclusion that changes in estuarine flow throughout the wet season can impact the trophic structure of macrobenthos communities, confirming a link between lotic and marine communities. Moreover, SI signatures suggest that the species collected here exhibit overlapping trophic niches, indicating high level of inter-specific competition. This highlights that species in low-productivity areas, such as the one studied here, can experience high levels of competition even in physically controlled environments such as sandy beaches.

  11. Geochemistry of modern sediments from San Quintín coastal lagoon, Baja California: Implication for provenance

    OpenAIRE

    Luis Walter Daesslé; Gabriel Rendón-Márquez; Víctor F. Camacho-Ibar; Efraín A. Gutiérrez-Galindo; Evgueny Shumilin; Eduardo Ortiz-Campos

    2009-01-01

    A detailed regional grid of 97 surficial sediment samples is studied for the San Quintín coastal lagoon, which is a shallow embayment located adjacent to a “regionally-rare” intraplate-type basaltic terrain known as San Quintín volcanic fi eld. The infl uence that this unique lithology and other potencial sources have on the recent sediment geochemistry is discussed on the basis of geochemical, petrographic and sedimentological results. The sandy silts and silts in the lagoon are enriched in ...

  12. Sediment trap efficiency of paddy fields at the watershed scale in a mountainous catchment in northwest Vietnam

    Science.gov (United States)

    Slaets, Johanna I. F.; Schmitter, Petra; Hilger, Thomas; Vien, Tran Duc; Cadisch, Georg

    2016-06-01

    Composite agricultural systems with permanent maize cultivation in the uplands and irrigated rice in the valleys are very common in mountainous southeast Asia. The soil loss and fertility decline of the upland fields is well documented, but little is known about reallocation of these sediments within the landscape. In this study, a turbidity-based linear mixed model was used to quantify sediment inputs, from surface reservoir irrigation water and from direct overland flow, into a paddy area of 13 ha. Simultaneously, the sediment load exported from the rice fields was determined. Mid-infrared spectroscopy was applied to analyze sediment particle size. Our results showed that per year, 64 Mg ha-1 of sediments were imported into paddy fields, of which around 75 % were delivered by irrigation water and the remainder by direct overland flow during rainfall events. Overland flow contributed one-third of the received sandy fraction, while irrigated sediments were predominantly silty. Overall, rice fields were a net sink for sediments, trapping 28 Mg ha-1 a-1 or almost half of total sediment inputs. As paddy outflow consisted almost exclusively of silt- and clay-sized material, 24 Mg ha-1 a-1 of the trapped amount of sediment was estimated to be sandy. Under continued intensive upland maize cultivation, such a sustained input of coarse material could jeopardize paddy soil fertility, puddling capacity and ultimately food security of the inhabitants of these mountainous areas. Preventing direct overland flow from entering the paddy fields, however, could reduce sand inputs by up to 34 %.

  13. Nourishment practices on Australian sandy beaches: a review.

    Science.gov (United States)

    Cooke, Belinda C; Jones, Alan R; Goodwin, Ian D; Bishop, Melanie J

    2012-12-30

    It is predicted that the coastal zone will be among the environments worst affected by projected climate change. Projected losses in beach area will negatively impact on coastal infrastructure and continued recreational use of beaches. Beach nourishment practices such as artificial nourishment, replenishment and scraping are increasingly used to combat beach erosion but the extent and scale of projects is poorly documented in large areas of the world. Through a survey of beach managers of Local Government Areas and a comprehensive search of peer reviewed and grey literature, we assessed the extent of nourishment practices in Australia. The study identified 130 beaches in Australia that were subject to nourishment practices between 2001 and 2011. Compared to projects elsewhere, most Australian projects were small in scale but frequent. Exceptions were nine bypass projects which utilised large volumes of sediment. Most artificial nourishment, replenishment and beach scraping occurred in highly urbanised areas and were most frequently initiated in spring during periods favourable to accretion and outside of the summer season of peak beach use. Projects were generally a response to extreme weather events, and utilised sand from the same coastal compartment as the site of erosion. Management was planned on a regional scale by Local Government Authorities, with little monitoring of efficacy or biological impact. As rising sea levels and growing coastal populations continue to put pressure on beaches a more integrated approach to management is required, that documents the extent of projects in a central repository, and mandates physical and biological monitoring to help ensure the engineering is sustainable and effective at meeting goals.

  14. Bacterial sulfur cycle shapes microbial communities in surface sediments of an ultramafic hydrothermal vent field

    DEFF Research Database (Denmark)

    Schauer, Regina; Røy, Hans; Augustin, Nico;

    2011-01-01

    The ultramafic-hosted Logatchev hydrothermal field (LHF) is characterized by vent fluids, which are enriched in dissolved hydrogen and methane compared with fluids from basalt-hosted systems. Thick sediment layers in LHF are partly covered by characteristic white mats. In this study, these sedime......The ultramafic-hosted Logatchev hydrothermal field (LHF) is characterized by vent fluids, which are enriched in dissolved hydrogen and methane compared with fluids from basalt-hosted systems. Thick sediment layers in LHF are partly covered by characteristic white mats. In this study...

  15. A new and practical method to obtain grain size measurements in sandy shores based on digital image acquisition and processing

    Science.gov (United States)

    Baptista, P.; Cunha, T. R.; Gama, C.; Bernardes, C.

    2012-12-01

    Modern methods for the automated evaluation of sediment size in sandy shores relay on digital image processing algorithms as an alternative to time-consuming traditional sieving methodologies. However, the requirements necessary to guarantee that the considered image processing algorithm has a good grain identification success rate impose the need for dedicated hardware setups to capture the sand surface images. Examples are specially designed camera housings that maintain a constant distance between the camera lens and the sand surface, tripods to fix and maintain the camera angle orthogonal to the sand surface, external illumination systems that guarantee the light level necessary for the image processing algorithms, and special lenses and focusing systems for close proximity image capturing. In some cases, controlled image-capturing conditions can make the fieldwork more laborious which incurs in significant costs for monitoring campaigns considering large areas. To circumvent this problem, it is proposed a new automated image-processing algorithm that identifies sand grains in digital images acquired with a standard digital camera without any extra hardware attached to it. The accuracy and robustness of the proposed algorithm are evaluated in this work by means of a laboratory test on previously controlled grain samples, field tests where 64 samples (spread over a beach stretch of 65 km and with grain size ranging from 0.5 mm to 1.9 mm) were processed by both the proposed method and by sieving and finally by manual point count on all acquired images. The calculated root-mean-square (RMS) error between mean grain sizes obtained from the proposed image processing method and the sieve method (for the 64 samples) was 0.33 mm, and for the image processing method versus manual point counts comparison, with the same images, was 0.12 mm. The achieved correlation coefficients (r) were 0.91 and 0.96, respectively.

  16. Using Repeat LiDAR Surveys to Determine the Geomorphic Changes Related the Removal of the Marmot Dam on the Sandy River, Oregon

    Science.gov (United States)

    Matzek, C. D.; Ely, L. L.; O'Connor, J. E.

    2012-12-01

    The removal of the Marmot Dam on the Sandy River, Oregon in October 2007 released an estimated 430,000 m3 of sand and gravel downstream. Field surveys by Major and others (Major and others, USGS Professional Paper 1792) following the dam removal documented deposition of nearly half of the eroded sediment (215,000 m3) in the first 2 km downstream of the dam within a year of breaching. However, the fate of more than 200,000 m3 of chiefly sand transported farther downstream is uncertain. In the current study, five sequential LiDAR data sets from 2006 to 2011 were used to quantify sediment storage and erosion in the 40 km from the former dam site to the confluence with the Columbia River to track the downstream movement of the sediment released from the reservoir. We hypothesized that a pulse of sediment from the dam removal would be distinguished by a successive downstream growth of sediment bars through time. The LiDAR imagery includes two data sets acquired before the dam removal and three afterward. Geomorphic Change Detection software (GCD) (gcd.joewheaton.org) was used to quantify the locations and volume of sediment erosion and deposition through the successive years of LiDAR imagery. GCD allows for error assessment of each LiDAR-derived digital elevation map (DEM) and propagates the combined errors when differencing two repeat surveys. This process allows creation of DEM of Difference (DoD) maps with associated uncertainty estimates. Preliminary results of the LiDAR analysis agree with the previous field estimates of deposition within the first 2 km from the former dam. Following the initial phase of deposition immediately downstream of the dam breach, the subsequent surveys (2008-2011) show an erosional front beginning to migrate downstream through the newly deposited sediment. Many of the sediment bars still remained in 2011, but were reduced in size. After calibrating the model in the 2-km reach below the dam, we analyzed the additional 38 km of channel

  17. Risk Evaluation of Sandy Coast Erosion Disaster in Hebei Province%河北省砂质海岸侵蚀灾害危险性评价

    Institute of Scientific and Technical Information of China (English)

    裴丽娜; 刘松涛; 孙娟

    2016-01-01

    The coast erosion is a common phenomenon of marine geological disasters in the world. This article conducted the study of sandy coast erosion disaster by field surveys in Heibei province. According to the historical documents, six evaluation indexes were selected to evaluate the risk of erosion on the sandy coast, including the coast landform, shoreline curvature, erosion rate, beach development zone, sediment supplement and embankment project. As a consequence, the length of shoreline in high risk areas was 46.11 km, 102.54 km in the middle, and 59.95 km in the low areas, the proportion of shoreline accounts for 22.1%, 149.16%, 28.73%respectively.%海岸侵蚀是当今全球海岸普遍存在的海洋地质灾害现象,通过实地勘查对河北省砂质海岸侵蚀灾害进行研究,借助历史资料,选取了海岸地貌类型、岸线曲度、侵蚀速率、海滩发育空间、泥沙补给和堤防设施六个评价指标,对河北省砂质海岸侵蚀灾害进行了危险性评价。评价结果表明:高危区岸线长度46.11 km,中危区102.54 km,低危区59.95 km,所占岸线比例依次为22.11%、49.16%及28.73%。

  18. Benthic macrofauna of sandy intertidal zone at Santos estuarine system, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    T.N. Corbisier

    1991-01-01

    Full Text Available Species composition, faunal density, species diversity and zonation patterns of benthic macrofauna, as well as its relation to sediment characteristics were examined and compared in three sandy beaches on the polyhaline area at Santos estuarine system in the State of São Paulo. Samples were collected quarterly during one year (July/1977 - May/1978. Low, mean and high intertidal levels were sampled. Polyehaetes dominated the fauna, both in terms of numbers of species and numbers of individuals. The community structure of Ponta da Praia beach was characterized by high density, low diversity (H' and evenness (J', due to the dominance of the spionid Scolelepis squamata. At Vicente de Carvalho the fauna was characterized by the dominance of the polyehaetes Laeonereis acuta and Capitella capitata and presented low density, high diversity and evenness. At Bertioga Channel, intermediate values were observed and the fauna was dominated by Scololepis squamata andLaeonereis acuta. The sediment texture was responsible for those figures, although some differences in diversity may be explained by differences in wave energy. The low number of crustaceans and molluscs suggests the effect of the estuarine pollution upon the fauna. The zonation pattern of both species distribution and community structure differed at the studied sites; it was not correlated with sediment characteristics which were relatively uniform down shore; however, the lowest diversity was observed at the high level in all sites.Neste trabalho foi estudada a macrofauna bentônica da zona entremarés arenosa da área polihalina do sistema estuarino de Santos. A composição em espécies, densidade e diversidade e o padrão de zonação da fauna foram analisados e comparados, bem como sua relação com as características do sedimento em três praias arenosas. As amostras foram coletadas trimestralmente durante o período de um ano (julho/1977 - maio/1978. Em cada local, foram amostrados os n

  19. Predominant Nearshore Sediment Dispersal Patterns in Manila Bay

    Directory of Open Access Journals (Sweden)

    Fernando Siringan

    1997-12-01

    Full Text Available Net nearshore sediment drift patterns in Manila Bay were determined by combining the coastal geomorphology depicted in 1 : 50,000scale topographic maps and Synthetic Aperture Radar (SAR images, with changes in shoreline position and predominant longshore current directions derived from the interaction of locally generated waves and bay morphology.Manila Bay is fringed by a variety of coastal subenvironments that reflect changing balances of fluvial, wave, and tidal processes. Along the northern coast, a broad tidal-river delta plain stretching from Bataan to Bulacan indicates the importance of tides, where the lateral extent of tidal influences is amplified by the very gentle coastal gradients. In contrast, along the Cavite coast sandy strandplains, spits, and wave-dominated deltas attest to the geomorphic importance of waves that enter the bay from the South China Sea.The estimates of net sediment drift derived from geomorphological, shoreline-change, and meteorological information are generally in good agreement. Sediment drift directions are predominantly to the northeast along Cavite, to the northwest along Manila and Bulacan, and to the north along Bataan. Wave refraction and eddy formation at the tip of the Cavite Spit cause southwestward sediment drift along the coast from Zapote to Kawit. Geomorphology indicates that onshore-offshore sediment transport is probably more important than alongshore transport along the coast fronting the tidal delta plain of northern Manila Bay. Disagreements between the geomorphic-derived and predicted net sediment drift directions may be due to interactions of wave-generated longshore currents with wind- and tide-generated currents.

  20. Estuarine sedimentation, sediment character, and foraminiferal distribution in central San Francisco Bay, California

    Science.gov (United States)

    Chin, John L.; Woodrow, Donald L.; McGann, Mary; Wong, Florence L.; Fregoso, Theresa; Jaffe, Bruce E.

    2010-01-01

    Central San Francisco Bay is the deepest subembayment in the San Francisco Bay estuary and hence has the largest water volume of any of the subembayments. It also has the strongest tidal currents and the coarsest sediment within the estuary. Tidal currents are strongest over the west-central part of central bay and, correspondingly, this area is dominated by sand-size sediment. Much of the area east of a line from Angel Island to Alcatraz Island is characterized by muddy sand to sandy mud, and the area to the west of this line is sandy. The sand-size sediment over west-central bay furthermore is molded by the energetic tidal currents into bedforms of varying sizes and wavelengths. Bedforms typically occur in water depths of 15-25 m. High resolution bathymetry (multibeam) from 1997 and 2008 allow for subdivision of the west-central bayfloor into four basic types based on morphologic expression: featureless, sand waves, disrupted/man-altered, and bedrock knobs. Featureless and sand-wave morphologies dominate the bayfloor of west-central bay. Disrupted bayfloor has a direct association with areas that are undergoing alteration due to human activities, such as sand-mining lease areas, dredging, and disposal of dredge spoils. Change detection analysis, comparing the 1997 and 2008 multibeam data sets, shows that significant change has occurred in west-central bay during the roughly 10 years between surveys. The surveyed area lost about 5.45 million m3 of sediment during the decade. Sand-mining lease areas within west-central bay lost 6.77 million m3 as the bayfloor deepened. Nonlease areas gained 1.32 million m3 of sediment as the bayfloor shallowed slightly outside of sand-mining lease areas. Furthermore, bedform asymmetry did not change significantly, but some bedforms did migrate some tens of meters. Gravity cores show that the area east of Angel and Alcatraz Islands is floored by clayey silts or silty sand whereas the area to the west of the islands is floored

  1. A vacuum-operated pore-water extractor for estuarine and freshwater sediments

    Science.gov (United States)

    Winger, P.V.; Lasier, P.J.

    1991-01-01

    A vacuum-operated pore-water extractor for estuarine and freshwater sediments was developed and constructed from a fused-glass air stone attached with aquarium airline tubing to a 30 or 60 cc polypropylene syringe. Pore water is extracted by inserting the air stone into the sediment and creating a vacuum by retracting and bracing the syringe plunger. A hand-operated vacuum pump attached to a filtration flask was also evaluated as an alternative vacuum source. The volume and time to extract pore water varies with the number of devices and the sediment particle size. Extraction time is longer for fine sediments than for sandy sediments. Four liters of sediment generally yield between 500 and 1,500 mL of pore water. The sediment that surrounds and accumulates on the air stone acts as a filter, and, except for the first few milliliters, the collected pore water is clear. Because there is no exposure to air or avenue for escape, volatile compounds andin situ characteristics are retained in the extracted pore water.

  2. Methane oxidation in permeable sediments at hydrocarbon seeps in the Santa Barbara Channel, California

    Science.gov (United States)

    Treude, T.; Ziebis, W.

    2010-03-01

    A shallow-water area in the Santa Barbara Channel (California), known collectively as the Coal Oil Point seep field, is one the largest natural submarine oil and gas emission areas in the world. Both gas and oil are seeping constantly through a predominantly sandy seabed into the ocean. This study focused on the methanotrophic activity within the surface sediments (0-15 cm) of the permeable seabed in the so-called Brian Seep area at a water depth ~10 m. Detailed investigations of biogeochemical parameters in the sediment surrounding active gas vents indicated that methane seepage through the permeable seabed induces a convective transport of fluids within the surface sediment layer, which results in a deeper penetration of oxidants (oxygen, sulfate) into the sediment, as well as in a faster removal of potentially inhibiting reduced end products (e.g. hydrogen sulfide). Methanotrophic activity was often found close to the sediment-water interface, indicating the involvement of aerobic bacteria. However, biogeochemical data suggests that the majority of methane is consumed by anaerobic oxidation of methane (AOM) coupled to sulfate reduction below the surface layer (>15 cm), where sulfate is still available in high concentrations. This subsurface maximum of AOM activity in permeable sands is in contrast to known deep-sea seep habitats, where upward fluid advection through more fine-grained sediments leads to an accumulation of AOM activity within the top 10 cm of the sediments, because sulfate is rapidly depleted.

  3. Mixed sand and gravel beaches: accurate measurement of active layer depth and sediment transport volumes using PIT tagged tracer pebbles

    Science.gov (United States)

    Holland, A.; Moses, C.; Sear, D. A.; Cope, S.

    2016-12-01

    As sediments containing significant gravel portions are increasingly used for beach replenishment projects globally, the total number of beaches classified as `mixed sand and gravel' (MSG) increases. Calculations for required replenishment sediment volumes usually assume a uniform layer of sediment transport across and along the beach, but research into active layer (AL) depth has shown variations both across shore and according to sediment size distribution. This study addresses the need for more accurate calculations of sediment transport volumes on MSG beaches by using more precise measurements of AL depth and width, and virtual velocity of tracer pebbles. Variations in AL depth were measured along three main profile lines (from MHWS to MLWN) at Eastoke, Hayling Island (Hampshire, UK). Passive Integrated Transponder (PIT) tagged pebbles were deployed in columns, and their new locations repeatedly surveyed with RFID technology. These data were combined with daily dGPS beach profiles and sediment sampling for detailed analysis of the influence of beach morphodynamics on sediment transport volumes. Data were collected over two consecutive winter seasons: 2014-15 (relatively calm, average wave height sandy lower foreshore reduced the AL to 10% of wave height in this area. The disparity in AL depth across the beach profile indicates that traditional models are not accurately representing bulk sediment transport on MSG beaches. It is anticipated that by improving model inputs, beach managers will be better able to predict necessary volumes and sediment grain size proportions of replenishment material for effective management of MSG beaches.

  4. Enzyme activities in the water column and in shallow permeable sediments from the northeastern Gulf of Mexico

    Science.gov (United States)

    Arnosti, C.; Ziervogel, K.; Ocampo, L.; Ghobrial, S.

    2009-09-01

    The activities of extracellular enzymes that initiate the microbial remineralization of high molecular weight organic matter were investigated in the water column and sandy surface sediments at two sites in the northeastern Gulf of Mexico. Six fluorescently labeled polysaccharides were hydrolyzed rapidly in the water column as well as in permeable sediments. This result contrasts with previous studies carried out in environments dominated by fine-grained muds, in which the spectrum of enzymes active in the water column is quite limited compared to that of the underlying sediments. Extracts of Spirulina, Isochrysis, and Thalassiosira were also used to measure hydrolysis rates in water from one of the sites. Rates of hydrolysis of the three plankton extracts were comparable to those of the purified polysaccharides. The broad spectrum and rapid rates of hydrolysis observed in the water column at both sites in the northeastern Gulf of Mexico may be due to the permeable nature of the sediments. Fluid flux through the sediments is sufficiently high that the entire 1.5 m deep water column could filter though the sediments on timescales of a few days to two weeks. Movement of water through sediments may also transport dissolved enzymes from the sediment into the water column, enhancing the spectrum as well as the rate of water column enzymatic activities. Such interaction between the sediments and water column would permit water column microbial communities to access high molecular weight substrates that might otherwise remain unavailable as substrates.

  5. Storm impacts on a high energy sandy beach system, northwest Ireland: short (event) to long term (decadal) behaviour

    Science.gov (United States)

    Guisado-Pintado, Emilia; Jackson, Derek; Cooper, Andrew; O'Connor, Marianne

    2017-04-01

    system at the northern part of the site over the medium to long term. We also observe that modal conditions favour intertidal beach recovery in the short and medium term, with a resulting southerly drift of sediment with an offshore return of sediment via the ebb-channel (multi-year response). This work demonstrates that coastal hazard analysis, approached at an appropriate site-specific scale and with suitable numerical modelling and field techniques, must include capturing data on nearshore forcing parameters that are driving shoreline response over various timescales. Understanding of these nearshore and intertidal morphodynamics is an important prelude to examining how a sandy shoreline behaves in response to high energy forcing. We advocate that morphodynamic self-adjustment of the beach system to a set of varying climatic conditions associated with increases in storminess, will have important implications for future coastline response.

  6. Indicators and impact analysis of sediment from the Changjiang Estuary and East China Sea to the Hangzhou Bay

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; FAN Wei; YUN Caixing

    2004-01-01

    Based on the historical evolution of the Hangzhou Bay, by making use of the conclusions made by the previous research workers and the integration of concrete data, five distinct impact indicators of the sediment from the Changjiang Estuary and the East China Sea to the Hangzhou Bay are summarized. Numerical calculation and analysis indicate that the scouring and deposition of seabed in the Hangzhou Bay are subject to the direct impact of the evolution of the Changjiang Estuary, and the growth and decline and the direction of the sandy bar at Nanhuizui give traces to the sediment transport between the Changjiang Estuary and the Hangzhou Bay. The transport of sediment from the Changjiang Estuary to the Hangzhou Bay occurs mainly in winter and spring seasons and the increase of the Changjiang River runoff and the decrease of sediment charge have caused scouring in the northern coast of the Hangzhou Bay and the seabed erosion along the frontal margin of the Changjiang River Delta.

  7. Effect of Coarse Particle Volume Fraction on the Yield Stress of Muddy Sediments from Marennes Oléron Bay

    Directory of Open Access Journals (Sweden)

    A. Pantet

    2010-01-01

    Full Text Available Coastal erosion results from a combination of various factors, both natural and humaninduced, which have different time and space patterns. In addition, uncertainties still remain about the interactions of the forcing agents, as well as on the significance of non-local causes of erosion. We focused about the surface sediments in the Marennes Oléron bay, after a general description of the site that has many various activities. The superficial sediments show a mechanical behavior, mainly depends on the fine fraction for a composition that contains up to 60% of sandy material. Fine sediments fraction has a typical yield stress depending naturally of concentration or water content. This yield could be modified slightly or significantly by adding silt or sand. As a result, the rheological measurement sensitivity allows us to characterize five typical sediments that correlate with solid fraction and fine fraction.

  8. Near-real-time Forensic Disaster Analysis: experiences from hurricane Sandy

    Science.gov (United States)

    Kunz, Michael; Mühr, Bernhard; Schröter, Kai; Kunz-Plapp, Tina; Daniell, James; Khazai, Bijan; Wenzel, Friedemann; Vannieuwenhuyse, Marjorie; Comes, Tina; Münzberg, Thomas; Elmer, Florian; Fohringer, Joachim; Lucas, Christian; Trieselmann, Werner; Zschau, Jochen

    2013-04-01

    Hurricane Sandy was the last tropical cyclone of the 2012 Northern Atlantic Hurricane season that made landfall. It moved on an unusual track from the Caribbean to the East Coast of the United States from 24 to 30 October as a Category 1 and 2 Hurricane according to the Saffir-Simpson Scale. Along its path, the severe storm event caused widespread damage including almost 200 fatalities. In the early hours of 30 October, Sandy made landfall near Atlantic City, N.J. Sandy was an extraordinary event due to its multihazard nature and several cascading effects in the aftermath. From the hydro-meteorological perspective, most unusual was the very large spatial extent of up to 1,700 km. High wind speeds were associated with record breaking storm surges at the U.S. Mid- Atlantic and New England Coast during high (astronomical) tide, leading to widespread flooding. Though Sandy was not the most severe storm event in terms of wind speed and precipitation, the impact in the U.S. was enormous with total damage estimates of up to 90 billion US (own estimate from Dec. 2012). Although much better data emerge weeks after such an event, the Forensic Disaster Analysis (FDA) Task Force of the Center for Disaster Management and Risk Reduction Technology (CEDIM) made an effort to obtain a comprehensive and holistic overview of the causes, hazardous effects and consequences associated with Sandy immediately after landfall at the U.S. coast on 30 October 2012. This was done in an interdisciplinary way by collecting and compiling scattered and distributed information from available databases and sources via the Internet, by applying own methodologies and models for near-real time analyses developed in recent years, and by expert knowledge. This contribution gives an overview about the CEDIM-FDA analyses' results. It describes the situation that led to the extraordinary event, highlights the interaction of the tropical cyclone with other hydro-meteorological events, and examines the

  9. THE PROBLEMATIC OF SANDY LANDS IN PARANAVAI MUNICIPALITY –PR

    Directory of Open Access Journals (Sweden)

    Marcelo Eduardo Freres Stipp

    2005-05-01

    Full Text Available The sandy lands are a process of scouring with sand forming a sandy area, which correspondsto a reworking of the sands due its constant mobility, involving the transformation of notsolids deposits is sandy areas. This work tried to establish the characterization of thisphenomenon of scouring with sand in a local level, occurring in arenaceous areas in theNortheast of the state of Paraná, specifically in the urban site of Paranavaí. It was also madean evaluation of the environmental degradation as well as different causes for what provokedthese sandy areas. Being an area with a high level of soil decomposition with the highwaysroutes crossing it, it was necessary, besides bibliographic data that allowed a theoretical basis,a research applied in order to supply subsides for future planning related to the spaceorganization. The evolution of the use and soil occupation in this area has been processedwithin an urban planning which considered by no account neither soil characteristic, thevegetation nor the predominant climate in that region. The mechanisms of region atmospherecirculation were analyzed, the alterations or attributes of the climate as well, aiming toidentify the genesis of the erosion sandy and possible time and space distribution. Initially, themain characteristics of the region were collected, components e processes working on the landmodel. It was observed how it worked and the use and occupation of the soil in past times andcurrently. During 2004, using the Environmental Fragility Letter, the areas of erosion wereidentified, ravines and strong erosion that compounds the first stages of the focused problem.The sandy land is a process that involves erosion, transport, e accumulation, meaning most oftimes the loosing of Biosphere productivity. For monitoring these risk areas some measuringcanes were made to measure the soil loss, which were used in several spots of erosion in theurban area in Paranavaí. The measurement happened in

  10. Stream-sediment geochemistry in mining-impacted streams : sediment mobilized by floods in the Coeur d'Alene-Spokane River system, Idaho and Washington

    Science.gov (United States)

    Box, Stephen E.; Bookstrom, Arthur A.; Ikramuddin, Mohammed

    2005-01-01

    below the confluence of the North and South Forks, and then increase again downstream of the gradient flattening below Cataldo. Metal contents of suspended sediment in the Spokane River below Coeur d'Alene Lake were comparable to those of suspended sediment in the main stem of the Coeur d'Alene River above the lake during the 1997 spring runoff, but with somewhat higher Zn contents. Daily suspended-sediment loads were about 100 times larger in the 1996 flood (50-100-year recurrence interval) than in the smaller 1997 floods (2-5-year recurrence intervals). Significant differences in metal ratios and contents are also apparent between the two flood types. The predominant source of suspended sediment in the larger 1996 flood was previously deposited, metal-enriched flood-plain sediment, identified by its Zn/Pb ratio less than 1. Suspended sediment in the smaller 1997 floods had metal ratios distinct from those of the flood-plain deposits and was primarily derived from metal-enriched sediment stored within the stream channel, identified by a Zn/Pb ratio greater than 1. Sediment deposited during overbank flooding on the immediate streambank or natural levee of the river typically consists of sandy material with metal ratios and contents similar to those of the sandy streambed sediment in the adjacent river reach. Samples of overbank deposits in backlevee marshes collected after the 1996 flood have metal ratios similar to those of peak-flow suspended sediment in the same river reach, but generally lower metal contents.

  11. Topography and sedimentary characteristics of the sandy beach of Kavaratti (Lakshadweep) - a premonsoonal study

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, K.V.; Shyam, K.R.; Varma, P.U.; Sivadas, P.

    During the southwest monsoon beach sediments on the western coast of Kavaratti are transported from the southern tip of the island to its northern tip. After the monsoon the littoral current reverses and the redistribution of the sediments takes...

  12. Sediment Core Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation and expertise for physical and geoacoustic characterization of marine sediments. DESCRIPTION: The multisensor core logger measures...

  13. Sediment Core Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation and expertise for physical and geoacoustic characterization of marine sediments.DESCRIPTION: The multisensor core logger measures...

  14. Dynamics of Cohesive Sediments

    DEFF Research Database (Denmark)

    Johansen, Claus

    the nature of the cohesive sediment with respect to the transport processes is presented. In addition, the flocculation process and the rheological behaviour of cohesive sediments is outlined. The second part contains the laboratory experiments. The laboratory experiments were conducted with respect......The present thesis considers the transport processes of cohesive sediments. The cohesive sediment used in the laboratory experiments was kaolinite, a clay mineral, in order to be able to reproduce the individual experiments. In the first part of the thesis, the theoretical considerations regarding...

  15. VARIABILITY OF KD VALUES IN CEMENTITIOUS MATERIALS AND SEDIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Almond, P.; Kaplan, D.; Shine, E.

    2012-02-02

    Measured distribution coefficients (K{sub d} values) for environmental contaminants provide input data for performance assessments (PA) that evaluate physical and chemical phenomena for release of radionuclides from wasteforms, degradation of engineered components and subsequent transport of radionuclides through environmental media. Research efforts at SRNL to study the effects of formulation and curing variability on the physiochemical properties of the saltstone wasteform produced at the Saltstone Disposal Facility (SDF) are ongoing and provide information for the PA and Saltstone Operations. Furthermore, the range and distribution of plutonium K{sub d} values in soils is not known. Knowledge of these parameters is needed to provide guidance for stochastic modeling in the PA. Under the current SRS liquid waste processing system, supernate from F & H Tank Farm tanks is processed to remove actinides and fission products, resulting in a low-curie Decontaminated Salt Solution (DSS). At the Saltstone Production Facility (SPF), DSS is mixed with premix, comprised of blast furnace slag (BFS), Class F fly ash (FA), and portland cement (OPC) to form a grout mixture. The fresh grout is subsequently placed in SDF vaults where it cures through hydration reactions to produce saltstone, a hardened monolithic waste form. Variation in saltstone composition and cure conditions of grout can affect the saltstone's physiochemical properties. Variations in properties may originate from variables in DSS, premix, and water to premix ratio, grout mixing, placing, and curing conditions including time and temperature (Harbour et al. 2007; Harbour et al. 2009). There are no previous studies reported in the literature regarding the range and distribution of K{sub d} values in cementitious materials. Presently, the Savannah River Site (SRS) estimate ranges and distributions of K{sub d} values based on measurements of K{sub d} values made in sandy SRS sediments (Kaplan 2010). The actual

  16. Thraustochytrids (fungoid protist: an unexplored component of marine sediment microbiota

    Directory of Open Access Journals (Sweden)

    Lucia Bongiorni

    2004-04-01

    Full Text Available Thraustochytrids are poorly known fungoid protists able to decompose refractory organic substrates such as cellulose. These microorganisms probably play an important role in the microbial loop of marine sediments. This paper reports a study conducted on thraustochytrids dwelling in a sandy shore of the Eastern Ligurian Sea. One hundred twenty eight samples (1 ml each were collected, to examine Thraustochytrid spatial distribution, following a nested ANOVA design, that incorporated 3 successively smaller spatial scales (different sampling units ranging from metres to centimetres. Samples were examined by a direct, improved, fluorochrome-count method also suitable for ciliates. Sampling was repeated 4 times in autumn-winter. The average abundance of thraustochytrids (±SE was 42.3±2.9 ml-1, with no significant decrease over time. The densities of thraustochytrids and ciliates varied significantly but at different spatial scales: the former between squares (3.3 x 3.3 m, and the latter between subplots (0.01 x 0.01m, indicating their tendency to form patches at different spatial scales. A significant correlation was found between the densities of the two protists, suggesting some interaction between them could occur. The thraustochytrid abundance supports the idea that these protists play a an important role in carbon cycling of Mediterranean sandy shores.

  17. Evolution and Impacts of a New Inlet Formed in Fire Island National Park by Superstorm Sandy (Invited)

    Science.gov (United States)

    Flood, R. D.; Flagg, C. N.; Goff, J. A.; Austin, J. A.; Schwab, W. C.; Denny, J. F.; Christensen, B. A.; Browne, C. M.; Saustrup, S.

    2013-12-01

    Superstorm Sandy impacted the New York / New Jersey area on October 29, 2012 and brought a storm surge of 1.5 to 2.5 m and waves with a significant wave height of 9.5 m to the south shore of Long Island, New York. The storm cut three inlets across Fire Island barrier islands. Two of the inlets were closed mechanically, but the third inlet, cut through a wilderness area of the Fire Island National Seashore, remains open and provides a rare opportunity to study the evolution and dynamics of an unmanaged inlet. This new inlet formed where Fire Island is narrow and is near the site of an earlier inlet that closed in 1825. Great South Bay (GSB) is located between Fire Island and the Long Island mainland. The salinity in GSB increased by 5 salinity units following the breach and has remained high. GSB has had chronic water quality issues associated with a high population density that may be moderated by flow related to the new inlet. Water flow through the new inlet is controlled by the difference between offshore tide and GSB tide, but GSB tide does not appear to have been altered by flow through the inlet. This is different from the traditional view of inlet dynamics where a balance is sought between channel cross-sectional area, tidal prism (which together give channel velocity) and longshore sediment transport. At SoMAS we have been monitoring the evolution of the new inlet since its formation. We have conducted overflights at 1 to 3 week intervals to track the changing inlet geometry and the location of flood-tidal and ebb-tidal deltas. We have also done small-boat bathymetric surveys of the channel itself every 3 to 5 weeks to track the shape and cross-sectional area of the channel. The channel was quite small shortly after the breach with a depth of about 2 m. The channel grew fast as it cut into underlying fine-grain sediments, reaching a depth of over 6 m following several late winter storms. The inlet channel initially migrated quickly to the west, but its

  18. Hurricane Sandy science plan: impacts of environmental quality and persisting contaminant exposure

    Science.gov (United States)

    Caskie, Sarah A.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: • Coastal topography and bathymetry

  19. Hurricane Sandy science plan: impacts to coastal ecosystems, habitats, and fish and wildlife

    Science.gov (United States)

    Campbell, Warren H.

    2013-01-01

    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: • Coastal topography and bathymetry

  20. Transitions in climate and energy discourse between Hurricanes Katrina and Sandy

    CERN Document Server

    Cody, Emily M; Bagrow, James P; Dodds, Peter Sheridan; Danforth, Christopher M

    2015-01-01

    Although climate change and energy are intricately linked, their explicit connection is not always prominent in public discourse and the media. Disruptive extreme weather events, including hurricanes, focus public attention in new and different ways, offering a unique window of opportunity to analyze how a focusing event influences public opinion. Simultaneously shaping and reflecting public discourse, media coverage of extreme weather events reflects public opinion of climate issues. Here we analyze climate and energy media coverage of Hurricanes Katrina (2005) and Sandy (2012) using topic models, mathematical techniques used to discover abstract topics within a set of documents. Our results demonstrate that post-Katrina media coverage does not contain a climate change topic, and the energy topic is limited to discussion of energy prices, markets, and the economy with almost no explicit linkages made between energy and climate change. In contrast, post-Sandy media coverage does contain a prominent climate ch...