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Sample records for fine sand beach

  1. Sand supply to beaches

    Science.gov (United States)

    Aagaard, Troels

    2017-04-01

    In most cases, beaches and dunes are built by sand that has been transported onshore from the shoreface. While this has been known for a long time, we are still not able to quantitatively predict onshore sediment transport and sand supply to beaches. Sediment transport processes operating during brief, high-energy stormy conditions - when beaches erode and sand moves offshore - are fairly well known and they can be modelled with a reasonable degree of confidence. However, the slower onshore sand transport leading to beach recovery under low-to-moderate energy conditions - and the reason why beaches and dunes exist in the first place - is not yet well understood. This severely limits our capability to understand and predict coastal behaviour on long time scales, for example in response to changing sea level or wave conditions. This paper will discuss issues and recent developments in sediment transport measurement and prediction on the lower and upper shoreface and into the swash zone. The focus will be on the integration and upscaling of small-scale deterministic process measurements into parametric models that may increase modelling capabilities of coastal behaviour on larger temporal and spatial scales.

  2. Sand hazards on tourist beaches.

    Science.gov (United States)

    Heggie, Travis W

    2013-01-01

    Visiting the beach is a popular tourist activity worldwide. Unfortunately, the beach environment is abundant with hazards and potential danger to the unsuspecting tourist. While the traditional focus of beach safety has been water safety oriented, there is growing concern about the risks posed by the sand environment on beaches. This study reports on the death and near death experience of eight tourists in the collapse of sand holes, sand dunes, and sand tunnels. Each incident occurred suddenly and the complete burial in sand directly contributed to the victims injury or death in each case report.

  3. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  4. Spatial and temporal variations of sediment size on a mixed sand and gravel beach

    Science.gov (United States)

    Horn, Diane P.; Walton, Susan M.

    2007-12-01

    Mixed sand and gravel beaches have been the subject of comparatively few studies in the UK. This paper describes the sediment distribution before, during and after a programme of beach nourishment along a section of mixed sand and gravel beach forming part of the Pevensey Bay Coastal Defences, in East Sussex, UK. The beach was recharged in September 2002, and beach profiles were measured along three cross-shore transects from August 2002 to February 2003. Sediment samples were taken along the transects between August and November 2002, and a total of 147 sediment samples were analysed, 40 before nourishment and 107 after nourishment. The majority of the sediment samples were strongly bimodal, with mean sizes varying between a minimum of 0.18 mm (2.48 ϕ) for the sand fraction and a maximum of 27 mm (- 4.74 ϕ) for the gravel. The recharge material was also bimodal but contained more fine sediment than the natural beach material, particularly on the upper beach. The recharge sediment had grain sizes and sorting similar to some of the natural material but lower bimodality parameters than any of the natural sediment. The sediment distributions after recharge contained significantly more fine sediment, particularly on the upper beach. Over time, the beach profile lowered and fine sediment appeared to be selectively transported seawards from the beachface.

  5. Release of Escherichia coli from Foreshore Sand and Pore Water during Intensified Wave Conditions at a Recreational Beach.

    Science.gov (United States)

    Vogel, Laura J; O'Carroll, Denis M; Edge, Thomas A; Robinson, Clare E

    2016-06-01

    Foreshore beach sands and pore water may act as a reservoir and nonpoint source of fecal indicator bacteria (FIB) to surface waters. This paper presents data collected at a fine sand beach on Lake Huron, Canada over three field events. The data show that foreshore sand erosion as wave height increases results in elevated Escherichia coli concentrations in surface water, as well as depletion of E. coli from the foreshore sand and pore water. E. coli initially attached to foreshore sand rather than initially residing in the pore water was found to be the main contributor to elevated surface water concentrations. Surface water E. coli concentrations were a function of not only wave height (and associated sand erosion) but also the time elapsed since a preceding period of high wave intensity. This finding is important for statistical regression models used to predict beach advisories. While calculations suggest that foreshore sand erosion may be the dominant mechanism for releasing E. coli to surface water during intensified wave conditions at a fine sand beach, comparative characterization of the E. coli distribution at a coarse sand-cobble beach suggests that interstitial pore water flow and discharge may be more important for coarser sand beaches.

  6. Microbes in Beach Sands: Integrating Environment, Ecology and Public Health.

    Science.gov (United States)

    Whitman, Richard; Harwood, Valerie J; Edge, Thomas A; Nevers, Meredith; Byappanahalli, Muruleedhara; Vijayavel, Kannappan; Brandão, João; Sadowsky, Michael J; Alm, Elizabeth Wheeler; Crowe, Allan; Ferguson, Donna; Ge, Zhongfu; Halliday, Elizabeth; Kinzelman, Julie; Kleinheinz, Greg; Przybyla-Kelly, Kasia; Staley, Christopher; Staley, Zachery; Solo-Gabriele, Helena M

    2014-09-01

    Beach sand is a habitat that supports many microbes, including viruses, bacteria, fungi and protozoa (micropsammon). The apparently inhospitable conditions of beach sand environments belie the thriving communities found there. Physical factors, such as water availability and protection from insolation; biological factors, such as competition, predation, and biofilm formation; and nutrient availability all contribute to the characteristics of the micropsammon. Sand microbial communities include autochthonous species/phylotypes indigenous to the environment. Allochthonous microbes, including fecal indicator bacteria (FIB) and waterborne pathogens, are deposited via waves, runoff, air, or animals. The fate of these microbes ranges from death, to transient persistence and/or replication, to establishment of thriving populations (naturalization) and integration in the autochthonous community. Transport of the micropsammon within the habitat occurs both horizontally across the beach, and vertically from the sand surface and ground water table, as well as at various scales including interstitial flow within sand pores, sediment transport for particle-associated microbes, and the large-scale processes of wave action and terrestrial runoff. The concept of beach sand as a microbial habitat and reservoir of FIB and pathogens has begun to influence our thinking about human health effects associated with sand exposure and recreational water use. A variety of pathogens have been reported from beach sands, and recent epidemiology studies have found some evidence of health risks associated with sand exposure. Persistent or replicating populations of FIB and enteric pathogens have consequences for watershed/beach management strategies and regulatory standards for safe beaches. This review summarizes our understanding of the community structure, ecology, fate, transport, and public health implications of microbes in beach sand. It concludes with recommendations for future work in

  7. Beach Sand Supply and Transport at Kunduchi in Tanzania and ...

    African Journals Online (AJOL)

    OCEAN. Mombasa. Dar es. Salaam. KUNDUCHI. KENYA. TANZANIA ... Figure 2. a) Reef-platform transects at Bamburi. b) Beach plain sand ..... comprised coral debris covered by turf algae .... and ocean acidification should not be ruled.

  8. Fine particle deposition at Vainguinim tourist beach, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Jayakumar, S.; SanilKumar, V.; Ilangovan, D.

    . The beach sediments consist primarily shell fragments and quartz, with heavy mineral composed of ilmenits, magnetite and manganese. The black stain of the fine-grained heavy minerals deposited on the beach face reduces the aesthetics of the beach. This paper...

  9. Olivine sand from Kawashiri Beach in Kagoshima, Japan

    OpenAIRE

    MATSUI, Tomoaki; マツイ, トモアキ; 松井, 智彰

    2001-01-01

    The olivine sand from Kawashiri Beach was studied by chemical and X-ray analyses. At least six groups of olivine are mixed in the olivine sand in this region, and they are classified according to the composition of the silicate-melt inclusions in them. The composition of the olivine sand ranges from Fo_70 to Fo_75, and the sum of the Mn_2SiO_4 and Ca_2SiO_4 content is less than 1 (mol %). These crystal chemical data for the olivine sand not only provide basic mineralogical info...

  10. An experiment to restore coastal sand dunes at Miramar beach, Goa: An appraisal

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    . Loss of vegetation is attributed to continuous trampling by humans, resulting in the creation of loose free sand that gets transported landwards. During windy days, large quantities of beach sand are blown from the beach and subsequently accumulate...

  11. Documenting the global impacts of beach sand mining

    Science.gov (United States)

    Young, R.; Griffith, A.

    2009-04-01

    For centuries, beach sand has been mined for use as aggregate in concrete, for heavy minerals, and for construction fill. The global extent and impact of this phenomenon has gone relatively unnoticed by academics, NGOs, and major news sources. Most reports of sand mining activities are found at the very local scale (if the mining is ever documented at all). Yet, sand mining in many localities has resulted in the complete destruction of beach (and related) ecosystems along with severe impacts to coastal protection and tourism. The Program for the Study of Developed Shorelines at Western Carolina University and Beachcare.org have initiated the construction of a global database of beach sand mining activities. The database is being built through a combination of site visits and through the data mining of media resources, peer reviewed papers, and reports from private and governmental entities. Currently, we have documented sand mining in 35 countries on 6 continents representing the removal of millions of cubic meters of sand. Problems extend from Asia where critical infrastructure has been disrupted by sand mining to the Caribbean where policy reform has swiftly followed a highly publicized theft of sand. The Program for the Study of Developed Shorelines recently observed extensive sand mining in Morocco at the regional scale. Tens of kilometers of beach have been stripped of sand and the mining continues southward reducing hope of a thriving tourism-based economy. Problems caused by beach sand mining include: destruction of natural beaches and the ecosystems they protect (e.g. dunes, wetlands), habitat loss for globally important species (e.g. turtles, shorebirds), destruction of nearshore marine ecosystems, increased shoreline erosion rates, reduced protection from storms, tsunamis, and wave events, and economic losses through tourist abandonment and loss of coastal aesthetics. The threats posed by sand mining are made even more critical given the prospect of a

  12. Cluster analysis of radionuclide concentrations in beach sand

    NARCIS (Netherlands)

    de Meijer, R.J.; James, I.; Jennings, P.J.; Keoyers, J.E.

    This paper presents a method in which natural radionuclide concentrations of beach sand minerals are traced along a stretch of coast by cluster analysis. This analysis yields two groups of mineral deposit with different origins. The method deviates from standard methods of following dispersal of

  13. Weather and environmental factors associated with F+ coliphages and fecal indicator bacteria in beach sand at two recreational marine beaches

    Science.gov (United States)

    Studies have demonstrated that fecal indicator bacteria (FIB) and pathogens may be present in beach sand and suggest an increased risk of enteric illness among beachgoers contacting sand. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR...

  14. [Microbiological quality of seaside sands: a beach in Latium].

    Science.gov (United States)

    Bonadonna, Lucia; Briancesco, Rossella; Cataldo, Claudia; Di Girolamo, Irene

    2002-01-01

    This study is focused on the microbiological quality of a sandy beach in the coastal area around Rome, Italy. The microbiological surveys were carried out on the sands collected both on the beach and on the waterline. A low-concentration of faecal bacteria (streptococci outnumbered Escherichia coli) and a constant rate of staphylococci were detected over the sampling period. Significant statistical correlations were calculated between yeasts and moulds, Escherichia coli and streptococci, streptococci and sulfite-reducing clostridium spores. This survey's data could be a baseline for future studies.

  15. Comparison of the occurrence and survival of fecal indicator bacteria in recreational sand between urban beach, playground and sandbox settings in Toronto, Ontario.

    Science.gov (United States)

    Staley, Zachery R; Robinson, Clare; Edge, Thomas A

    2016-01-15

    While beach sands are increasingly being studied as a reservoir of fecal indicator bacteria (FIB), less is known about the occurrence of FIB in other recreational sands (i.e., sandboxes and playgrounds). In this study, different culture-based FIB enumeration techniques were compared and microbial source tracking assays were conducted on recreational sand samples from beaches, playgrounds and sandboxes around Toronto, ON. FIB were detected in every sand sample (n=104) with concentrations not changing significantly over the five month sampling period. Concentrations of FIB and a gull-specific DNA marker were significantly higher in foreshore beach sands, and indicated these were a more significant reservoir of FIB contamination than sandbox or playground sands. Human- and dog-specific contamination markers were not detected. All culture-based FIB enumeration techniques were consistent in identifying the elevated FIB concentrations associated with foreshore beach sands. However, significant differences between differential agar media, IDEXX and Aquagenx Compartment Bag Test were observed, with DC media and Enterolert being the most sensitive methods to detect Escherichia coli and enterococci, respectively. To better understand the elevated occurrence of E. coli in foreshore sands, microcosm survival experiments were conducted at two different temperatures (15 °C and 28 °C) using non-sterile saturated foreshore beach sands collected from two urban freshwater beaches with different sand type (fine grain and sand-cobble). Microcosms were inoculated with a mixture of eight sand-derived E. coli strains and sampled over a 28-day period. E. coli levels were found to decline in all microcosms, although survival was significantly greater in the finer sand and at the cooler temperature (15 °C). These results indicate that FIB can be widespread in any type of recreational sand and, while E. coli can survive for many weeks, it is most likely to accumulate in cooler fine

  16. Present status of effect of microorganisms from sand beach on public health

    Directory of Open Access Journals (Sweden)

    Emmanuel Velonakis

    2014-09-01

    Full Text Available Microorganisms are significant components of beach sand. According to the research, all kind of microorganisms have been isolated from beach sand; certain genera and species are potential pathogens for humans and animals. In resort areas, especially during the summer, certain infections (e.g. gastroenteritis and dermatitis are usually related to polluted bathing water. Lately, the interest of scientists is also focused on the potential association of some of the above diseases with the beach sand. Relatively, recent epidemiological studies in the USA revealed positive correlation between time spent at the beach and gastroenteritis. New parameters such as wind blowing and beach users’ density are also introduced for discussion in association with the sand microbial load. Regarding the preventative measures, the microbiological quality of beach sand can be improved by raising the general level of hygiene, as well as by using simple methods, such as sweeping and aeration of the sand, together with constant beach supervision.

  17. Present status of effect of microorganisms from sand beach on public health

    Institute of Scientific and Technical Information of China (English)

    Emmanuel Velonakis; Dimitra Dimitriadi; Emmanuel Papadogiannakis; Alkiviades Vatopoulos

    2014-01-01

    Microorganisms are significant components of beach sand. According to the research, all kind of microorganisms have been isolated from beach sand; certain genera and species are potential pathogens for humans and animals. In resort areas, especially during the summer, certain infections (e.g. gastroenteritis and dermatitis) are usually related to polluted bathing water. Lately, the interest of scientists is also focused on the potential association of some of the above diseases with the beach sand. Relatively, recent epidemiological studies in the USA revealed positive correlation between time spent at the beach and gastroenteritis. New parameters such as wind blowing and beach users’ density are also introduced for discussion in association with the sand microbial load. Regarding the preventative measures, the microbiological quality of beach sand can be improved by raising the general level of hygiene, as well as by using simple methods, such as sweeping and aeration of the sand, together with constant beach supervision.

  18. Water quality, weather and environmental factors associated with fecal indicator organism density in beach sand at two recreational marine beaches

    Science.gov (United States)

    Heaney, Christopher D.; Exum, Natalie G.; Dufour, Alfred P.; Brenner, Kristen P.; Haugland, Richard A.; Chern, Eunice; Schwab, Kellogg J.; Love, David C.; Serre, Marc L.; Noble, Rachel; Wade, Timothy J.

    2015-01-01

    Recent studies showing an association between fecal indicator organisms (FIOs) in sand and gastrointestinal (GI) illness among beachgoers with sand contact have important public health implications because of the large numbers of people who recreate at beaches and engage in sand contact activities. Yet, factors that influence fecal pollution in beach sand remain unclear. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, sand samples were collected at three locations (60 m apart) on weekend days (Sat, Sun) and holidays between June and September at two marine beaches — Fairhope Beach, AL and Goddard Beach, RI — with nearby publicly-owned treatment works (POTWs) outfalls. F+ coliphage, enterococci, Bacteroidales, fecal Bacteroides spp., and Clostridium spp. were measured in sand using culture and qPCR-based calibrator-cell equivalent methods. Water samples were also collected on the same days, times and transects as the 144 sand samples and were assayed using the same FIO measurements. Weather and environmental data were collected at the time of sample collection. Mean FIO concentrations in sand varied over time, but not space. Enterococci CFU and CCE densities in sand were not correlated, although other FIOs in sand were. The strongest correlation between FIO density in sand and water was fecal Bacteroides CCE, followed by enterococci CFU, Clostridium spp. CCE, and Bacteroidales CCE. Overall, the factors associated with FIO concentrations in sand were related to the sand–water interface (i.e., sand-wetting) and included daily average densities of FIOs in water, rainfall, and wave height. Targeted monitoring that focuses on daily trends of sand FIO variability, combined with information about specific water quality, weather, and environmental factors may inform beach monitoring and management decisions to reduce microbial burdens in beach sand. The views expressed in this paper are those of the authors

  19. Assessment of Enterococcus Levels in Recreational Beach Sand Along the Rhode Island Coast.

    Science.gov (United States)

    Coakley, Eugenie; Parris, Amie L; Wyman, Al; Latowsky, Gretchen

    2016-04-01

    Recent studies have shown that coastal beach sand as well as coastal ocean water can be contaminated with fecal indicator Enterococcus bacteria (ENT). A study of sand ENT concentrations over a four-week period at 12 Rhode Island beaches was conducted during the summer of 2009. While average contamination was low relative to water quality standards, every beach had at least one day with very high sand ENT readings. On 10 of the 12 beaches, a statistically significant gradient occurred in geometric mean ENT concentrations among tidal zones, with dry (supratidal, or above high tide mark) sand having the highest level, followed by wet (intratidal, or below high tide mark) and underwater sand. Beaches with higher wave action had significantly lower ENT levels in wet and underwater sand compared to beaches with lower wave action.

  20. Aeolian sand transport and its effects on the stability of Miramar-Caranzalem beach

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, G.V.; Sastry, J.S.

    Removal of sand by wind from the beach at Miramar-Caranzalem, Goa, has been found to effect its stability over a relatively longer time scale. This aeolian sand transport has been computed for this strip of the beach utilising the relation between...

  1. From Sand to Rock: a teaching activity to introduce beach dynamics.

    Science.gov (United States)

    Gravina, Teresita

    2015-04-01

    The Italian coastline is about 7,500 km long; approximately 53% of the coastlines are low or deltaic coastlines, while 3,240 km were mainly composed of sand or gravel beaches. Most of the Italian coastal environment suffers from intense and growing urbanization, tourism and industry pressure, which could partly explain that 42% of Italian beaches experience erosion. Terracina is situated Lazio (Central Italy), a region strongly impacted by coastal erosion, and for this reason we organized a teaching activity, carried out with fourth year high school classes, in order to help students to understand sand beach dynamics, acquisition of geology issues and land conservation and preservation skills. We decided to focus our activity on the mineralogical composition of beach sand in order to relate beach formations with the geological evolution of the territory. Sand beach minerals were used as tracers in order to support students to understand dynamics that influence beach formations. In addition to mineral characteristic recognition, this activity allows us to introduce the beach balance concept and the phenomena that regulate sediment balance, in order to allow students to consider beaches as a resource which needs to be preserved. Sand mineralogical composition data is treated in a worksheet to elaborate simple statistical analysis in order to recognize the mineral composition of Terracina beach sand's rock sources. This exercise allows students to find relationships between regional geology and beach sand's composition. Finally, statistical evidence could be compared with geological maps of the area in order to find the probable provenance of sand's rock source and rocks recognition thanks to related morphologies. Our main purpose was to help students to understand that beaches are dynamic systems subject to anthropogenic pressure and for this reason they needed to be preserved. Proposed teaching activities involve topics related to students' living territory and to

  2. Routine screening of harmful microorganisms in beach sands: implications to public health

    Science.gov (United States)

    Sabino, Raquel; Rodrigues, R.; Costa, I.; Carneiro, Carlos; Cunha, M.; Duarte, A.; Faria, N.; Ferriera, F.C.; Gargate, M.J.; Julio, C.; Martins, M.L.; Nevers, Meredith; Oleastro, M.; Solo-Gabriele, H.; Verissimo, C.; Viegas, C.; Whitman, Richard L.; Brandao, J.

    2014-01-01

    Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the “Microareias 2012” workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications.

  3. Beach monitoring project Sand Key Phase II Beach nourishment program (North Redington Beach and Redington Shores) Post-Nourishment Report Part II Offshore Profiles and Wave Data

    OpenAIRE

    1989-01-01

    This study presents the third post-nourishment survey (January 1989) results for the Sand Key Phase II beach nourishment project carried out in June, 1988. The monitoring program to this beach nourishment project is a joint effort between the University of South Florida and University of Florida. The field surveys include a total of 26 profiles, encompassing approximately 3 miles of shoreline extending from DNR R-96 to R-1ll. The total calculated volume loss of sand in the n...

  4. Origin of modern quartzarenite beach sands in a temperate climate, Florida and Alabama, USA

    Science.gov (United States)

    Mehring, Joseph L.; McBride, Earle F.

    2007-10-01

    Quartzarenite coastal sands extending from eastern Louisiana eastward to Apalachee Bay, Florida, are anomalous: their position 7° north of the Tropic of Cancer contrasts with most other known modern quartzarenites, most of which are in a tropical setting. To determine the origin of these quartzarenite beach sands, we compared the mineralogy of samples taken from Alabama and Florida beaches, rivers that supply sand to the coast, and well cuttings representative of sandstone bedrock exposed in the Alabama coastal plain. To help assess the abundance of recycled quartz, and accepting the conventional wisdom that rounded sand-size quartz grains are recycled, we quantified the roundness of quartz grains in thin sections of river, beach, and well samples. We also determined the abundance of recycled grains with authigenic quartz using cathodoluminescence. River sands on Precambrian and Paleozoic bedrock in the study area have subarkose and sublitharenite compositions. However, as far as 200 km inland from the coast, river sands have attained quartzarenite composition and all rivers are presently delivering sand with at least 97% quartz to the coast. Rivers develop quartzarenite sand composition where they traverse poorly consolidated Tertiary sandstones, all of which we sampled are composed of > 95% quartz. Published experimental work indicates that abrasional rounding of sand-size quartz by rivers is insignificant and rounding in beaches is extremely slow. Hence, the abundance of quartz grains with some degree of rounding (96% for beaches; > 75% for rivers) further attests to the abundance of recycled quartz.

  5. Comparing different methods for fast screening of microbiological quality of beach sand aimed at rapid-response remediation.

    Science.gov (United States)

    Testolin, Renan C; Almeida, Tito C M; Polette, Marcus; Branco, Joaquim O; Fischer, Larissa L; Niero, Guilherme; Poyer-Radetski, Gabriel; Silva, Valéria C; Somensi, Cleder A; Corrêa, Albertina X R; Corrêa, Rogério; Rörig, Leonardo R; Itokazu, Ana Gabriela; Férard, Jean-François; Cotelle, Sylvie; Radetski, Claudemir M

    2017-05-15

    There is scientific evidence that beach sands are a significant contributor to the pathogen load to which visitors are exposed. To develop beach quality guidelines all beach zones must be included in microbiological evaluations, but monitoring methods for beach sand quality are relatively longstanding, expensive, laborious and require moderate laboratory infrastructure. This paper aimed to evaluate the microorganism activity in different beach zones applying and comparing a classical method of membrane filtration (MF) with two colorimetric screening methods based on fluorescein (FDA) and tetrazolium (TTC) salt biotransformation to evaluate a new rapid and low-cost method for beach sand microbiological contamination assessments. The colorimetric results can help beach managers to evaluate rapidly and at low cost the microbiological quality of different beach zones in order to decide whether remedial actions need to be adopted to prevent exposure of the public to microbes due to beach sand and/or water contamination. Copyright © 2017. Published by Elsevier Ltd.

  6. Restoration of sand dunes along human-altered coasts: a scheme for Miramar beach, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    This paper examines the state of sand dunes of a developed coast by taking the tourist beach of Miramar (Goa), India as an example. Human actions are responsible for the degradation and elimination of these geomorphic features. The associated...

  7. Intertidal benthic community ecology of sand-dwelling macroinvertebrates of Goa beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Studies on the intertidal ecology of two sandy beaches of Goa along the western coast of India revealed the presence of 47 species of macroinvertebrates belonging to 32 families. The open beach at Candolim, characterized by coarse sand-grain size...

  8. Microbiological and mycological beach sand quality in a volcanic environment: Madeira archipelago, Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Elisabete; Figueira, Celso; Aguiar, Nuno; Vasconcelos, Rita [Universidade da Madeira, Caminho da Penteada, 9020-105 Funchal (Portugal); Vasconcelos, Sílvia [Laboratório Regional de Veterinária e Segurança Alimentar, Caminho das Quebradas de Baixo n° 79, 9000-254 Funchal (Portugal); Calado, Graça [Laboratório de Saúde Pública, IASaúde, Rua das Pretas n° 1, 9004-515 Funchal (Portugal); Brandão, João [Instituto Nacional de Saúde Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisboa (Portugal); Prada, Susana, E-mail: susana@uma.pt [Universidade da Madeira, Caminho da Penteada, 9020-105 Funchal (Portugal); Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Rua da Mãe de Deus, Edifício do Complexo Científico, 3° Andar — Ala Sul, 9500-321 Ponta Delgada (Portugal)

    2013-09-01

    Madeira forms a mid-Atlantic volcanic archipelago, whose economy is largely dependent on tourism. There, one can encounter different types of sand beach: natural basaltic, natural calcareous and artificial calcareous. Microbiological and mycological quality of the sand was analyzed in two different years. Bacterial indicators were detected in higher number in 2010 (36.7% of the samples) than in 2011 (9.1%). Mycological indicators were detected in a similar percentage of samples in 2010 (68.3%) and 2011 (75%), even though the total number of colonies detected in 2010 was much higher (827 in 41 samples) than in 2011 (427 in 66 samples). Enterococci and potentially pathogenic and allergenic fungi (particularly Penicillium sp.) were the most common indicators detected in both years. Candida sp. yeast was also commonly detected in the samples. The analysis of the 3rd quartile and maximum numbers of all indicators in samples showed that artificial beaches tend to be more contaminated than the natural ones. However, a significant difference between the variables was lacking. More monitoring data (number of bathers, sea birds, radiation intensity variation, and a greater number of samples) should be collected in order to confirm if these differences are significant. In general, the sand quality in the archipelago's beaches was good. As the sand may be a vector of diseases, an international common set of indicators and values and a compatible methodologies for assessing sand contamination, should be defined, in order to provide the bather's with an indication of beach sand quality, rather than only the water. - Highlights: • Microbial indicators were studied in the beach sands of Madeira archipelago. • Differences between years may be attributed to extreme weather. • Sand of artificial beaches has higher levels of microbial contamination. • Microbial analysis of the sand showed that the beaches have mainly good quality.

  9. Measurement of natural radioactivity in Brazilian beach sands

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, R. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Sanches, N. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Anjos, R.M. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil)]. E-mail: meigikos@if.uff.br; Macario, K. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Bastos, J. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Iguatemy, M. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Aguiar, J.G. [Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho, Fundacentro C.P. 11484, 05499-970 Sao Paulo, SP (Brazil); Santos, A.M.A. [Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho, Fundacentro C.P. 11484, 05499-970 Sao Paulo, SP (Brazil); Mosquera, B. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Carvalho, C. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Baptista Filho, M. [Instituto de Fisica da Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/no, Gragoata, 24210-340 Niteroi, RJ (Brazil); Umisedo, N.K. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil)

    2006-02-15

    The distribution of natural radionuclide {gamma}-ray activities and their respective annual effective dose rates, produced by {sup 40}K, {sup 226}Ra and {sup 232}Th, were determined for sand samples collected along the coast of four Brazilian States: Sao Paulo (SP), Rio de Janeiro (RJ), Espirito Santo (ES) and Bahia (BA). For some specific beaches, the values of the annual effective dose rates or {gamma}-ray radiation hazard indices exceed the average worldwide exposure of 2.4mSvy{sup -1} due to natural sources and the limits proposed by Organization for Economic Co-operation and Development for building materials. The average values of the radium equivalent activities were evaluated and found to be 696Bqkg{sup -1} in Mambucaba (RJ), 1621Bqkg{sup -1} in Buena (RJ), 2289Bqkg{sup -1} in Anchieta (ES), 10205Bqkg{sup -1} in Meaipe (ES), 83425Bqkg{sup -1} in Guarapari (ES), 531Bqkg{sup -1} in Vitoria (ES), 2026Bqkg{sup -1} in Serra (ES), 3240Bqkg{sup -1} in Sao Mateus (ES), 3075Bqkg{sup -1} in Porto Seguro (BA) and 1841Bqkg{sup -1} in Itacare (BA). These values are above the limit of 370Bqkg{sup -1} recommended for the safe use of building materials for dwellings by OECD.

  10. Densities and antimicrobial resistance of Escherichia coli isolated from marine waters and beach sands.

    Science.gov (United States)

    Andrade, Vanessa da Costa; Zampieri, Bruna Del Busso; Ballesteros, Eliete Rodrigues; Pinto, Aline Bartelochi; de Oliveira, Ana Julia Fernandes Cardoso

    2015-06-01

    Bacterial resistance is a rising problem all over the world. Many studies have showed that beach sands can contain higher concentration of microorganisms and represent a risk to public health. This paper aims to evaluate the densities and resistance to antimicrobials of Escherichia coli strains, isolated from seawater and samples. The hypothesis is that microorganisms show higher densities in contaminated beach sands and more antimicrobial resistance than the water column. Density, distribution, and antimicrobial resistance of bacteria E. coli were evaluate in seawater and sands from two recreational beaches with different levels of pollution. At the beach with higher degree of pollution (Gonzaguinha), water samples presented the highest densities of E. coli; however, higher frequency of resistant strains was observe in wet sand (71.9 %). Resistance to a larger number of antimicrobial groups was observe in water (betalactamics, aminoglycosides, macrolides, rifampicins, and tetracyclines) and sand (betagalactamics and aminoglycosids). In water samples, highest frequencies of resistance were obtain against ampicilin (22.5 %), streptomycin (15.0 %), and rifampicin (15.0 %), while in sand, the highest frequencies were observe in relation to ampicilin (36.25 %) and streptomycin (23.52 %). At the less polluted beach, Ilha Porchat, highest densities of E. coli and higher frequency of resistance were obtain in wet and dry sand (53.7 and 53.8 %, respectively) compared to water (50 %). Antimicrobial resistance in strains isolated from water and sand only occurred against betalactamics (ampicilin and amoxicilin plus clavulanic acid). The frequency and variability of bacterial resistance to antimicrobials in marine recreational waters and sands were related to the degree of fecal contamination in this environment. These results show that water and sands from beaches with a high index of fecal contamination of human origin may be potential sources of contamination by pathogens

  11. Fine sand in motion: the influence of interstitial air

    NARCIS (Netherlands)

    Homan, T.A.M.

    2013-01-01

    Sand is a granular material, and therefore it consists of individual grains arranged in a packing. The pores in-between the grains are usually filled with a fluid, in this case air. Now, is this interstitial air able to influence the behavior of the sand bed as a whole? When a ball impacts on fine,

  12. Effect of the coastal conservation due to beach nourishment of Totori sand dune coast

    OpenAIRE

    Y. Shibutani; Matsubara, Y.; Kuroiwa, M.

    2013-01-01

    Tottori Sand Dune Coast located at western part of Japan is a sandy beach with a length about 8km facing Sea of Japan. The coast has been eroded starting around 1940s and the beach nourishment project has been carried out to restore the shoreline since 2005 at Tottori Sand Dune Coast. In the project, the deposition sands at port and river mouth were transported to the erosional area and injected in the region of the offshore erosional area and the backshore area and the total volumes of the s...

  13. Radioactivity of sand from several renowned public beaches and assessment of the corresponding environmental risks

    Directory of Open Access Journals (Sweden)

    MIRJANA B. RADENKOVIĆ

    2009-04-01

    Full Text Available The radiological risk due to the presence of natural and man-made radionuclides in beach sands from several renowned seaside and riverbank public beaches was estimated in this study. The exposure levels to terrestrial radiation of the beaches were determined, as well as hazards due to human use of the analyzed sands in industry and in building constructions. Specific radionuclides concentrations in the sand samples were determined by standard gamma-spectrometry. The corresponding radiation hazards arising due to the use of sand as a building material were estimated by three different radiological hazard indices. The total absorbed gamma dose rate in the air was determined and the corresponding annual effective dose outdoors was estimated. The obtained data are relevant both from human health and environmental monitoring aspects.

  14. Beach Nourishment Techniques. Report 3. Typical U.S. Beach Nourishment Projects Using Offshore Sand Deposits.

    Science.gov (United States)

    1981-05-01

    Cooperative Beach Erosion Control Project at Presque Isle Peninsula, Erie , Pennsylvania ," Buffalo, N. Y. U. S. Army Engineer District, Charleston. 1963 (Mar...104 Presque Isle , Pa .. .. ..................... 109 REFERENCES .. ............................ 115 2A BEACH NOURISHMENT...RIVER COUNTY, FL T PRESQUE ISLE . PA Figure 1. Beach fill projects location map ...../ ...... studies have been authorized, or which are publicly owned

  15. Effects of full-scale beach renovation on fecal indicator levels in shoreline sand and water.

    Science.gov (United States)

    Hernandez, Rafael J; Hernandez, Yasiel; Jimenez, Nasly H; Piggot, Alan M; Klaus, James S; Feng, Zhixuan; Reniers, Ad; Solo-Gabriele, Helena M

    2014-01-01

    Recolonization of enterococci, at a non-point source beach known to contain high background levels of bacteria, was studied after a full-scale beach renovation project. The renovation involved importation of new exogenous sand, in addition to infrastructure improvements. The study's objectives were to document changes in sand and water quality and to evaluate the relative contribution of different renovation activities towards these changes. These objectives were addressed: by measuring enterococci levels in the sand and fecal indicator bacteria levels (enterococci and fecal coliform) in the water, by documenting sediment characteristics (mineralogy and biofilm levels), and by estimating changes in observable enterococci loads. Analysis of enterococci levels on surface sand and within sediment depth cores were significantly higher prior to beach renovation (6.3-72 CFU/g for each sampling day) when compared to levels during and after beach renovation (0.8-12 CFU/g) (P < 0.01). During the renovation process, sand enterococci levels were frequently below detection limits (<0.1 CFU/g). For water, exceedances in the regulatory thresholds that would trigger a beach advisory decreased by 40% for enterococci and by 90% for fecal coliform. Factors that did not change significantly between pre- and post- renovation included the enterococci loads from animals (approx. 3 × 10(11) CFU per month). Factors that were observed to change between pre- and post- renovation activities included: the composition of the beach sand (64% versus 98% quartz, and a significant decrease in biofilm levels) and loads from direct stormwater inputs (reduction of 3 × 10(11) CFU per month). Overall, this study supports that beach renovation activities contributed to improved sand and water quality resulting in a 50% decrease of observable enterococci loads due to upgrades to the stormwater infrastructure. Of interest was that the change in the sand mineralogy also coincided with changes in biofilm

  16. THE MICROBIOLOGICAL AND SANITARY STATE OF SAND IN THE MUNICIPAL BATHING BEACH IN SZCZECIN

    Directory of Open Access Journals (Sweden)

    Kinga Zatoń

    2015-11-01

    Full Text Available Artificial beaches, i.e. places in the public sphere, are usually intended for recreation, located at water reservoirs, rivers, and their surface is naturally occurring or applied sand. The urban bathing beach located in Szczecin by the Deep lake has sand purchased and distributed on the beach by the Municipal Services Office in Szczecin (a few hundred ton. The beach is divided into sectors, a volleyball court is in one part, in the next section catering and sanitary facilities are located, and the remaining area is a place intended for sunbathing and playing games. The aim of the experiment was to assess the effects of different ways of using the beach on changes of microbiological properties of the sand. The tests were taken from the beach sand in May 2013 (first term examinations, and in September, after several months of use (the second term of examinations. The sand was collected near catering and sanitary sector (the first object and from the area of the volleyball court (the second object, as well as the playground for children (the third object. The facilities were distanced from the shoreline of the lake by approx. 8 metres. The comparison included the number of heterotrophic bacteria, fungi and the detected presence of coliform bacteria, including Escherichia coli, bacteria of the genus Salmonella and eggs of intestinal parasites. In any of the objects, or the periods of time, eggs of intestinal parasites and bacteria of the genus Salmonella were detected. The presence of coliform bacteria including E. coli was found in the sand collected from a catering-sanitary zone, there was also the biggest number of bacteria and fungi. The number of heterotrophic bacteria and fungi was similar in samples of sand taken from the volleyball court and from the playground, in this sand there was no bacteria belonging to the E. coli species, although in several samples from the playground other bacteria belonging to the coliform genus were detected. To

  17. Plastic pellets on the Caranzalem beach sands, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.

    Postmonsoonal survey of Caranzalem beach, Goa, India indicated the presence of plastic pellets. These pellets varied in shape, size and number, and are considered to be contaminants of marine environment...

  18. Evaluation of beach grooming techniques on Escherichia coli density in foreshore sand at North Beach, Racine, WI

    Science.gov (United States)

    Kinzelman, Julie L.; Whitman, Richard L.; Byappanahalli, Muruleedhara N.; Jackson, Emma; Bagley, Robert C.

    2003-01-01

    Elevated levels of Escherichia coli(E. coli) in bathing waters at North Beach, a popular recreational site in Racine, Wisconsin, have been a persistent problem often resulting in the issuance of poor water quality advisories. Moreover, waterfowl (mostly Larus delawarensis and L. argentatus) in nearshore and offshore areas are common and may serve as non-point sources for bacterial contamination of recreational waters. Current beach management practice involves daily mechanical grooming of the nearshore sand for aesthetics and removal of hazardous debris. However, this practice has not been evaluated in terms of its effects on E. coli loading to beach sand and potential introduction to contiguous swimming water. In this study, we tested E. coli responses to three treatments: mechanical groomer, daily and twice weekly hand raking, and a control (no raking/grooming). A randomized block design consisted of replicated treatments and one control (10 each), for a total of 40 blocks sampled daily for 10 days. Foreshore sand samples were collected by hand coring to an average depth of 10 cm. Median E. colirecovered were 73 (mechanically groomed), 27 (hand-raked daily), 32 (hand-raked twice weekly), and 22 (control) colony-forming units (CFU) per gram dry weight sand. E. colicounts in sand that was groomed were significantly higher than hand rakings and control (p grooming efficacy and the importance of understanding non-point sources of bacterial contamination.

  19. Physical Modeling of the Cross-Shore Sediment Transport on a Sand-Gravel Beach

    Science.gov (United States)

    Xharde, Regis; Brunelle, Corinne; Frandsen, Jannette

    2014-11-01

    The aim of the study is to investigate the cross-shore evolution of a nourished beach profile under storm wave conditions with specific emphasis on sediment transport within the breaking zone. To investigate the underlying mechanisms of the coastal transport processes, a physical model of the beach was built at scale 1:3 in the new Quebec Coastal Physics Laboratory (QCPL), Canada. The modeled beach is 4.2 m high, 5 m wide and 40 m long with a mean slope of 1:10. The beach is formed of a mixture of sediment with grain sizes ranging from 0.65 mm up to 20 mm. The stability of the beach is tested for operational and storm waves. We report on run-up and run-down processes via wave gages, video records of waves and ultrasonic water level measurements. Sediment transport processes within the surf zone and on the beach face are monitored using acoustic Doppler profilers and optical backscattering sensors. The beach profile is surveyed prior and after each test series using a topographic laser scanner. Initial results show that sand is transported off-shore to a breaker bar while cobbles are pushed on the upper beach by run-up. Details of the underlying mechanism of different breaker types and impact on sediment transport will be presented.

  20. Through the sands of time: Beach litter trends from nine cleaned north cornish beaches.

    Science.gov (United States)

    Watts, Andrew J R; Porter, Adam; Hembrow, Neil; Sharpe, Jolyon; Galloway, Tamara S; Lewis, Ceri

    2017-09-01

    Marine litter and its accumulation on beaches is an issue of major current concern due to its significant environmental and economic impacts. Yet our understanding of spatio-temporal trends in beach litter and the drivers of these trends are currently limited by the availability of robust long term data sets. Here we present a unique data set collected systematically once a month, every month over a six year period for nine beaches along the North Coast of Cornwall, U.K. to investigate the key drivers of beach litter in the Bude, Padstow and Porthcothan areas. Overall, an average of 0.02 litter items m(-2) per month were collected during the six year study, with Bude beaches (Summerleaze, Crooklets and Widemouth) the most impacted (0.03 ± 0.004 litter items m(-2) per month). The amount of litter collected each month decreased by 18% and 71% respectively for Padstow (Polzeath, Trevone and Harlyn) and Bude areas over the 6 years, possibly related to the regular cleaning, however litter increased by 120% despite this monthly cleaning effort on the Padstow area beaches. Importantly, at all nine beaches the litter was dominated by small, fragmented plastic pieces and rope fibres, which account for 32% and 17% of all litter items collected, respectively. The weathered nature of these plastics indicates they have been in the marine environment for an extended period of time. So, whilst classifying the original source of these plastics is not possible, it can be concluded they are not the result of recent public littering. This data highlights both the extent of the marine litter problem and that current efforts to reduce littering by beach users will only tackle a fraction of this litter. Such information is vital for developing effective management strategies for beach and marine litter at both regional and global levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The influence of rainfall on transport of beach sand by wind.

    NARCIS (Netherlands)

    Dijk, van P.M.; Stroosnijder, L.; Lima, de J.L.M.P.

    1996-01-01

    This paper deals with the effect of rainfall on the process of wind erosion of beach sands and presents results from both field and wind tunnel experiments. Although sediment transport by splash is of secondary importance on coastal dunes, splash-saltation processes can move sediments in conditions

  2. Moving sands along a headland-embayed beach system (Algarve, Southern Portugal)

    Science.gov (United States)

    Oliveira, Sónia; Horta, João; Nascimento, Ana; Gomes, Ana; Veiga-Pires, Cristina; Moura, Delminda

    2015-04-01

    Resilience of embayed and pocket beaches located at the southernmost coast of Portugal is currently a major question to coastal management of this region. In fact, several among those beaches have been artificially fed aiming to increase the width of the beach allowing people to maintain a safe distance to the unstable rocky cliffs. The sand is dredged from the offshore (ca. 2 miles from the shoreline) representing high costs for the Portuguese government. For how long will the artificial feeding solve the problem? Which beaches are worth being nourished taking into account the morphosedimentary processes? The present work is the result of a field experiment aiming to study the efficiency of the alongshore sedimentary transport between successive embayed beaches. The experiment was performed in the very indented rocky coast of the Algarve region (Southern Portugal) and comprised two field campaigns, both in 2014, during spring tides in March and November. The Algarve coast experiences a semi-diurnal meso-tidal regime ranging from 1.3 m during neap tides to 3.5 m at spring tides and the waves approach from WSW (232°) during 72% of observations along the year, almost normal to the study area shoreline. The wave and current characteristics (significant height-Hs and Period-T for waves, velocity and direction for currents) were measured during three and six tidal cycles respectively for the first and second campaign, using two pressure transducers and one electromagnetic current meter. We used sand painted with orange fluorescent dye (100 kg in March and 200 kg in November) as tracer to track the movement of the sand along the coast. The marked sand was placed on the beach face of the westernmost beach of the study area during the first low tide of each campaign. Following, hundreds of sediment samples were collected during low tide, through the monitored period, in the nodes of a georeferenced square mesh of 10 x 20 m covering three embayed beaches. Later in the

  3. Development of 3D beach evolution model for sand nourishments and its application to morphodynamics around coastal structures

    OpenAIRE

    Kuroiwa, M.; Matsubara, Y.; Fujitani, H.; H. Mase

    2013-01-01

    A numerical model to predict three-dimensional (3D) beach evolution after sand nourishment was developed. The injection process of sand to near shoreline or offshore area was expressed by the sediment flux in the conservation equation associated with sediment transports and water depth changes, furthermore, sand dredging process was considered. In this study, First, computation of beach evolution around a coastal structure with and without nourishment was carried out. Secondly, the develop...

  4. Holocene beach buildup and coastal aeolian sand incursions off the Nile littoral cell

    Science.gov (United States)

    Roskin, Joel; Sivan, Dorit; Shtienberg, Gilad; Porat, Naomi; Bookman, Revital

    2017-04-01

    Israel's coastal plain is abundant with sand originating from the Nile littoral cell. The inland windblown loose sand has formed 3-6 km wide lobe-like sand and dune fields currently comprised of foredunes, linear and northeasterly facing transverse and parabolic dunes that are currently stabilized by vegetation. This study reviews the architecture and history of the these dune fields aiming to: (a) Date the timings of beach accretion, and sand and dune incursions. (b) Discriminate between natural and human-induced forcing factors of sand mobilization and stabilization in time and space. (c) Present a model of the dunescape development. (d) Assess scenarios of sand transport in the future charcaterized by intense human impact and climate change. Luminescence ages, radiocarbon dates and relative ages from previously published geological and archaeological reports, historical texts, together with new optically stimulated luminescence (OSL) ages and stratigraphic and sedimentological data are analyzed. The deposition, mobilizations and preservation of the sand bodies, initially induced by the decline in sea level rise at 6-4 ka, were later controlled by historic land-use intensity and modern land-use/negligence practices. At 6 ka, beach sand buildup rapidly started. Where aeolianite ridges bordered the coast, pulses of sand with biogenic carbonate grains unconformably draped the ridges and rapidly consolidated into a distinct sandy calcarenite unit. Further east, sand sheets and low dunes partly pedogenized following their incursion, but did not cement. The water retention capacities of the sand sheets enabled the establishment of a sand-stabilizing vegetation cover that probably became an attractive environment for fuel and grazing. The growing Hellenistic-Roman-Byzantine ( 2.4-1.3 ka) populations probably led to increased consumption and massive destruction of sand stabilizing vegetation, enabling sand erodibility and mobilization during winter storms. The sand

  5. Microbiological and mycological beach sand quality in a volcanic environment: Madeira archipelago, Portugal.

    Science.gov (United States)

    Pereira, Elisabete; Figueira, Celso; Aguiar, Nuno; Vasconcelos, Rita; Vasconcelos, Sílvia; Calado, Graça; Brandão, João; Prada, Susana

    2013-09-01

    Madeira forms a mid-Atlantic volcanic archipelago, whose economy is largely dependent on tourism. There, one can encounter different types of sand beach: natural basaltic, natural calcareous and artificial calcareous. Microbiological and mycological quality of the sand was analyzed in two different years. Bacterial indicators were detected in higher number in 2010 (36.7% of the samples) than in 2011 (9.1%). Mycological indicators were detected in a similar percentage of samples in 2010 (68.3%) and 2011 (75%), even though the total number of colonies detected in 2010 was much higher (827 in 41 samples) than in 2011 (427 in 66 samples). Enterococci and potentially pathogenic and allergenic fungi (particularly Penicillium sp.) were the most common indicators detected in both years. Candida sp. yeast was also commonly detected in the samples. The analysis of the 3rd quartile and maximum numbers of all indicators in samples showed that artificial beaches tend to be more contaminated than the natural ones. However, a significant difference between the variables was lacking. More monitoring data (number of bathers, sea birds, radiation intensity variation, and a greater number of samples) should be collected in order to confirm if these differences are significant. In general, the sand quality in the archipelago's beaches was good. As the sand may be a vector of diseases, an international common set of indicators and values and a compatible methodologies for assessing sand contamination, should be defined, in order to provide the bather's with an indication of beach sand quality, rather than only the water. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Biodegradation of MC252 oil in oil:sand aggregates in a coastal headland beach environment.

    Science.gov (United States)

    Elango, Vijaikrishnah; Urbano, Marilany; Lemelle, Kendall R; Pardue, John H

    2014-01-01

    Unique oil:sand aggregates, termed surface residue balls (SRBs), were formed on coastal headland beaches along the northern Gulf of Mexico as emulsified MC252 crude oil mixed with sand following the Deepwater Horizon spill event. The objective of this study is to assess the biodegradation potential of crude oil components in these aggregates using multiple lines of evidence on a heavily-impacted coastal headland beach in Louisiana, USA. SRBs were sampled over a 19-month period on the supratidal beach environment with reasonable control over and knowledge of the residence time of the aggregates on the beach surface. Polycyclic aromatic hydrocarbons (PAHs) and alkane concentration ratios were measured including PAH/C30-hopane, C2/C3 phenanthrenes, C2/C3 dibenzothiophenes and alkane/C30-hopane and demonstrated that biodegradation was occurring in SRBs in the supratidal. These biodegradation reactions occurred over time frames relevant to the coastal processes moving SRBs off the beach. In contrast, submerged oil mat samples from the intertidal did not demonstrate chemical changes consistent with biodegradation. Review and analysis of additional biogeochemical parameters suggested the existence of a moisture and nutrient-limited biodegradation regime on the supratidal beach environment. At this location, SRBs possess moisture contents biodegradation in the literature. Despite these limitations, biodegradation of PAHs and alkanes proceeded at relevant rates (2-8 year(-1)) due in part to the presence of degrading populations, i.e., Mycobacterium sp., adapted to these conditions. For submerged oil mat samples in the intertidal, an oxygen and salinity-impacted regime is proposed that severely limits biodegradation of alkanes and PAHs in this environment. These results support the hypothesis that SRBs deposited at different locations on the beach have different biogeochemical characteristics (e.g., moisture, salinity, terminal electron acceptors, nutrient, and oil

  7. Natural radioactivity in sand beaches of Guarapari, Espirito Santo state, Brazil: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Danilo C.; Pereira, Claubia; Oliveira, Arno H.; Santos, Talita O.; Reis, Patricia L., E-mail: danilo@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear; Rocha, Zildete, E-mail: rochaz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MH (Brazil)

    2011-07-01

    Using gamma ray spectrometry, the activity concentration of naturally occurring radionuclides {sup 226}Ra, {sup 232}Th, and {sup 40}K was determined in sand beaches samples from different areas in Guarapari, Espirito Santo state, from Brazil. The absorbed dose rates and annual effective dose were calculated and the results are compared with the internationally accepted values as well as others high background radiation areas (HBRAs).The activity concentration of the {sup 232}Th in Areia Preta as well as the absorbed dose rates and annual effective dose were higher than the others regions compared. The results show that Areia Preta in Guarapari has higher background found in beaches in world. (author)

  8. A standardized method for sampling and extraction methods for quantifying microplastics in beach sand.

    Science.gov (United States)

    Besley, Aiken; Vijver, Martina G; Behrens, Paul; Bosker, Thijs

    2017-01-15

    Microplastics are ubiquitous in the environment, are frequently ingested by organisms, and may potentially cause harm. A range of studies have found significant levels of microplastics in beach sand. However, there is a considerable amount of methodological variability among these studies. Methodological variation currently limits comparisons as there is no standard procedure for sampling or extraction of microplastics. We identify key sampling and extraction procedures across the literature through a detailed review. We find that sampling depth, sampling location, number of repeat extractions, and settling times are the critical parameters of variation. Next, using a case-study we determine whether and to what extent these differences impact study outcomes. By investigating the common practices identified in the literature with the case-study, we provide a standard operating procedure for sampling and extracting microplastics from beach sand.

  9. Texture and composition of the Rosa Marina beach sands (Adriatic coast, southern Italy: a sedimentological/ecological approach

    Directory of Open Access Journals (Sweden)

    Moretti Massimo

    2016-06-01

    Full Text Available Beach sands from the Rosa Marina locality (Adriatic coast, southern Italy were analysed mainly microscopically in order to trace the source areas of their lithoclastic and bioclastic components. The main cropping out sedimentary units were also studied with the objective to identify the potential source areas of lithoclasts. This allowed to establish how the various rock units contribute to the formation of beach sands. The analysis of the bioclastic components allows to estimate the actual role of organisms regarding the supply of this material to the beach. Identification of taxa that are present in the beach sands as shell fragments or other remains was carried out at the genus or family level. Ecological investigation of the same beach and the recognition of sub-environments (mainly distinguished on the basis of the nature of the substrate and of the water depth was the key topic that allowed to establish the actual source areas of bioclasts in the Rosa Marina beach sands. The sedimentological analysis (including a physical study of the beach and the calculation of some statistical parameters concerning the grain-size curves shows that the Rosa Marina beach is nowadays subject to erosion.

  10. A GIS approach to model sediment reduction susceptibility of mixed sand and gravel beaches.

    Science.gov (United States)

    Eikaas, Hans S; Hemmingsen, Maree A

    2006-06-01

    The morphological form of mixed sand and gravel beaches is distinct, and the process/response system and complex dynamics of these beaches are not well understood. Process response models developed for pure sand or gravel beaches cannot be directly applied to these beaches. The Canterbury Bight coastline is apparently abundantly supplied with sediments from large rivers and coastal alluvial cliffs, but a large part of this coastline is experiencing long-term erosion. Sediment budget models provide little evidence to suggest sediments are stored within this system. Current sediment budget models inadequately quantify and account for the processes responsible for the patterns of erosion and accretion of this coastline. We outline a new method to extrapolate from laboratory experiments to the field using a geographical information system approach to model sediment reduction susceptibility for the Canterbury Bight. Sediment samples from ten representative sites were tumbled in a concrete mixer for an equivalent distance of 40 km. From the textural mixture and weight loss over 40 km tumbling, we applied regression techniques to generate a predictive equation for Sediment Reduction Susceptibility (SRS). We used Inverse Distance Weighting (IDW) to extrapolate the results from fifty-five sites with data on textural sediment composition to field locations with no data along the Canterbury Bight, creating a continuous sediment reductions susceptibility surface. Isolines of regular SRS intervals were then derived from the continuous surface to create a contour map of sediment reductions susceptibility for the Canterbury Bight. Results highlighted the variability in SRS along this coastline.

  11. Enhanced ex situ bioremediation of crude oil contaminated beach sand by supplementation with nutrients and rhamnolipids.

    Science.gov (United States)

    Nikolopoulou, M; Pasadakis, N; Norf, H; Kalogerakis, N

    2013-12-15

    Mediterranean coastal regions are particularly exposed to oil pollution due to extensive industrialization, urbanization and transport of crude and refined oil to and from refineries. Bioremediation of contaminated beach sand through landfarming is both simple and cost-effective to implement compared to other treatment technologies. The purpose of the present study was to investigate the effect of alternative nutrients on biodegradation of crude oil contaminated beach sand in an effort to reduce the time required for bioremediation employing only indigenous hydrocarbon degraders. A natural sandy soil was collected from Agios Onoufrios beach (Chania, Greece) and was contaminated with weathered crude oil. The indigenous microbial population in the contaminated sand was tested alone (control treatment) or in combination with inorganic nutrients (KNO3 and K2HPO4) to investigate their effects on oil biodegradation rates. In addition, the ability of biosurfactants (rhamnolipids), in the presence of organic nutrients (uric acid and lecithin), to further stimulate biodegradation was investigated in laboratory microcosms over a 45-day period. Biodegradation was tracked by GC/MS analysis of aliphatic and polycyclic aromatic hydrocarbons components and the measured concentrations were corrected for abiotic removal by hopane normalizations. It was found that the saturated fraction of the residual oil is degraded more extensively than the aromatic fraction and the bacterial growth after an incubation period of approximately 3 weeks was much greater from the bacterial growth in the control. The results show that the treatments with inorganic or organic nutrients are equally effective over almost 30 days where C12-C35n-alkanes were degraded more than 97% and polyaromatic hydrocarbons with two or three rings were degraded more than 95% within 45 days. The results clearly show that the addition of nutrients to contaminated beach sand significantly enhanced the activity of

  12. Natural Radioactivity of Beach Sand Samples in the Tripoli Region, Northwest Libya

    OpenAIRE

    2008-01-01

    A comprehensive study was conducted to determine the radioactivity concentrations of beach sand samples from different sites along the coast of Tripoli, northwest Libya, using high resolution g-ray spectroscopy. Collection of samples was carried out during low tide, where it was possible to collect sediments from the wet region that was covered by sea water during high tide. From the measured g-ray spectra, elemental concentrations were determined for 226Ra, 232Th, 40K, and 210Pb at...

  13. Pollutant advective spreading in beach sand exposed to high-energy tides

    Science.gov (United States)

    Itugha, Okuroghoboye D.; Chen, Daoyi; Guo, Yakun

    2016-11-01

    This paper presents field measurements in which dye solute was injected into coastal sand to investigate contaminant advection in intertidal beach sand. The measurements show the pathways of a contaminated plume in the unsaturated zone during both the flood and ebb tides. A prescribed amount of dye tracer solution was directly injected through the topsoil, with average porosity 0.3521 ± 0.01, at predetermined locations of the River Mersey's outer estuarial beach during ebb-tide. The injected dye was monitored, sampled and photographed over several tidal cycles. The distinctive features of the plume (full two dimensional cross-sections), sediments and water-table depth were sampled in-situ, close to the injection point (differing from previous contaminant monitoring tests in aquifers). The advective movement is attributed to tidal impact which is different from contaminant transport in aquifers. The experimental results show that plumes have significantly large spatial variability, diverging upwards and converging downwards, with a conical geometric shape which is different from the usual spherical/elliptical shape reported in literature. The mean vertical motion of the plume reaches three times the top-width within ten tidal cycles, exceeding the narrow bottom-width by a factor of order 2. The observed transport features of the plume within the beach sand have significant relevance to saltwater intrusion, surface water and groundwater quality. The field observations are unique and can serve as a valuable benchmark database for relevant numerical studies.

  14. Beach week: a high school graduation rite of passage for sun, sand, suds, and sex.

    Science.gov (United States)

    Schwartz, R H; Milteer, R; Sheridan, M J; Horner, C P

    1999-02-01

    Every year, thousands of suburban high school graduates from mid Atlantic states flock to nearby coastal beaches for a long-anticipated rite of passage known as "beach week." Sand, sun, and sea, and also smoking, binge drinking, drugs, and sex, are reported to be dominant themes. To document risk-taking behaviors by girls during beach week. Fifty-nine female suburban high school graduates who attended beach week in 1996 volunteered to fill out a confidential printed survey. Twenty-five girls (42%) completed the survey during a typical beach week party. Their activities were verified on site by a peer, recommended by her grade advisor for her integrity and popularity. Breath alcohol values were obtained at entry and departure from the party. The remaining 34 girls completed the supervised survey 2 to 3 months later. Daily cigarette smoking (54%), daily drunkenness (75%), and sex (46%) were the norm among respondents of our survey. Few reported first-time sex (n = 4) or drug use (n = 2). Abstinence from drugs (67%) and sex (55%) was not unusual but only 12% abstained from getting drunk. Sixteen girls (64%) reported that they drank 8 or more beers/wine during a typical beach week party. By departure from the party, 15 girls had breath alcohol values of 0.017 mmol/L or greater (reference range, <21.7 mmol/L), and 8 additional girls had breath alcohol values of 0.01 mmol/L to 0.015 mmol/L. Fifteen percent of the 59 reported injuries or illness were related to alcohol or drugs. Most respondents enjoyed beach week but a large percentage engaged in serious risk-taking behaviors.

  15. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand.

    Science.gov (United States)

    Nolet, Corjan; Poortinga, Ate; Roosjen, Peter; Bartholomeus, Harm; Ruessink, Gerben

    2014-01-01

    Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure surface moisture at a high spatio-temporal resolution. It is based on the principle that wet sand appears darker than dry sand: it is less reflective. The goals of this study are (1) to measure and model reflectance under controlled laboratory conditions as function of wavelength (λ) and surface moisture (θ) over the optical domain of 350-2500 nm, and (2) to explore the implications of our laboratory findings for accurately mapping the distribution of surface moisture under natural conditions. A laboratory spectroscopy experiment was conducted to measure spectral reflectance (1 nm interval) under different surface moisture conditions using beach sand. A non-linear increase of reflectance upon drying was observed over the full range of wavelengths. Two models were developed and tested. The first model is grounded in optics and describes the proportional contribution of scattering and absorption of light by pore water in an unsaturated sand matrix. The second model is grounded in soil physics and links the hydraulic behaviour of pore water in an unsaturated sand matrix to its optical properties. The optical model performed well for volumetric moisture content θ 0.97), but underestimated reflectance for θ between 24-30% (R2 > 0.92), most notable around the 1940 nm water absorption peak. The soil-physical model performed very well (R2 > 0.99) but is limited to 4% > θ < 24%. Results from a field experiment show that a short-wave infrared terrestrial laser scanner (λ = 1550 nm) can accurately relate surface moisture to reflectance (standard error 2.6%), demonstrating its potential to derive spatially extensive surface moisture maps of a natural coastal beach.

  16. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand.

    Directory of Open Access Journals (Sweden)

    Corjan Nolet

    Full Text Available Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure surface moisture at a high spatio-temporal resolution. It is based on the principle that wet sand appears darker than dry sand: it is less reflective. The goals of this study are (1 to measure and model reflectance under controlled laboratory conditions as function of wavelength (λ and surface moisture (θ over the optical domain of 350-2500 nm, and (2 to explore the implications of our laboratory findings for accurately mapping the distribution of surface moisture under natural conditions. A laboratory spectroscopy experiment was conducted to measure spectral reflectance (1 nm interval under different surface moisture conditions using beach sand. A non-linear increase of reflectance upon drying was observed over the full range of wavelengths. Two models were developed and tested. The first model is grounded in optics and describes the proportional contribution of scattering and absorption of light by pore water in an unsaturated sand matrix. The second model is grounded in soil physics and links the hydraulic behaviour of pore water in an unsaturated sand matrix to its optical properties. The optical model performed well for volumetric moisture content θ 0.97, but underestimated reflectance for θ between 24-30% (R2 > 0.92, most notable around the 1940 nm water absorption peak. The soil-physical model performed very well (R2 > 0.99 but is limited to 4% > θ < 24%. Results from a field experiment show that a short-wave infrared terrestrial laser scanner (λ = 1550 nm can accurately relate surface moisture to reflectance (standard error 2.6%, demonstrating its potential to derive spatially extensive surface moisture maps of a natural coastal beach.

  17. Modeling downstream fining in sand-bed rivers. II: Application

    Science.gov (United States)

    Wright, S.; Parker, G.

    2005-01-01

    In this paper the model presented in the companion paper, Wright and Parker (2005) is applied to a generic river reach typical of a large, sand-bed river flowing into the ocean in order to investigate the mechanisms controlling longitudinal profile development and downstream fining. Three mechanisms which drive downstream fining are studied: a delta prograding into standing water, sea-level rise, and tectonic subsidence. Various rates of sea-level rise (typical of the late Holocene) and tectonic subsidence are modeled in order to quantify their effects on the degree of profile concavity and downstream fining. Also, several other physical mechanisms which may affect fining are studied, including the relative importance of the suspended versus bed load, the effect of the loss of sediment overbank, and the influence of the delta bottom slope. Finally, sensitivity analysis is used to show that the grain-size distribution at the interface between the active layer and substrate has a significant effect on downstream fining. ?? 2005 International Association of Hydraulic Engineering and Research.

  18. Fecal indicator bacteria in tropical beach sand: Baseline findings from Port Dickson coastline, Strait of Malacca (Malaysia).

    Science.gov (United States)

    Praveena, Sarva Mangala; Shamira, Siti Shafiqa; Ismail, Sharifah Norkhadijah Syed; Aris, Ahmad Zaharin

    2016-09-15

    This pilot study aims to assess Escherichia coli (E. coli) contamination and its perceived health risks among beachgoers in ten tropical beach sands along Port Dickson coastline (Malaysia). This study also aims to determine the relationship between perceived health symptoms and tropical beach sand exposure behavior. The concentration of E. coli in tropical beach sand ranged from 60cfu/100g to 4113cfu/100g. E. coli contamination was the highest at Tanjung Gemuk (4113±30cfu/100g) and the lowest at Tanjung Tuan (60±15cfu/100g); the high level of contamination could be due to the location of the former at the sewage outlet of nearby hotels. Skin symptoms were the most predominant among the health symptoms indicated by beachgoers. Exposure duration was significantly correlated with the perceived health symptoms among beachgoers in the beaches studied.

  19. Biodegradation of MC252 oil in oil:sand aggregates in a coastal headland beach environment

    Directory of Open Access Journals (Sweden)

    Vijaikrishnah eElango

    2014-04-01

    Full Text Available Biodegradation potential of MC252 in oil:sand aggregates, termed surface residue balls (SRBs, was examined using multiple lines of evidence on a heavily-impacted coastal headland beach in Louisiana, USA. SRBs were sampled over a 16-month period on the supratidal beach environment where reasonable control existed on the residence time of the aggregates on the beach surface. PAH and alkane concentration ratios were measured including PAH/C30-hopane, C2/C3 phenanthrenes, C2/C3 dibenzothiophenes and alkane/C30-hopane and demonstrated unequivocally that biodegradation was occurring in SRBs in the supratidal. These biodegradation reactions occurred over time frames relevant to the coastal processes moving SRBs off the beach. In contrast, submerged oil mat (SOM samples did not demonstrate chemical changes consistent with biodegradation. Review and analysis of additional biogeochemical parameters suggested the existence of a moisture and N-limited biodegradation regime on the supratidal beach environment. At this location, SRBs possess moisture contents < 2% and molar C:N ratios from 131-323, well outside of optimal values for biodegradation in the literature. Despite these limitations, biodegradation of PAHs and alkanes proceeded at relevant rates (2-8 year-1 due in part to the presence of degrading populations, i.e., Mycobacterium sp., adapted to these conditions. For SOM samples in the intertidal, an oxygen and salinity-impacted regime is proposed that severely limits biodegradation of alkanes and PAHs in this environment. These results support the hypothesis that SRBs deposited at different locations on the beach have different biogeochemical characteristics (e.g., moisture; salinity; terminal electron acceptors; nutrient; and oil composition due, in part, to their location on the landscape.

  20. Effect of Fines on Liquefaction Resistance in Fine Sand and Silty Sand

    Directory of Open Access Journals (Sweden)

    Meraj Ahmad Khan

    2016-01-01

    Full Text Available It is required to recognize the conditions that exist in a soil deposit before an earthquake in order to identify liquefaction. Soil is basically an assemblage of many soil particles which stay in contact with many neighboring soil. The contact forces produced by the weight of the overlying particles holds individual soil particle in its place and provide strength. Occurrence of liquefaction is the result of rapid load application and break down of the loose and saturated sand and the loosely-packed individual soil particles tries to move into a denser configuration. However, there is not enough time for the pore-water of the soil to be squeezed out in case of earthquake. Instead, the water is trapped and prevents the soil particles from moving closer together. Thus, there is an increase in water pressure which reduces the contact forces between the individual soil particles causing softening and weakening of soil deposit. In extreme conditions, the soil particles may lose contact with each other due to the increased pore-water pressure. In such cases, the soil will have very little strength, and will behave more like a liquid than a solid - hence, the name "liquefaction".

  1. Biogeochemical characterization of MC252 oil:sand aggregates on a coastal headland beach.

    Science.gov (United States)

    Urbano, Marilany; Elango, Vijaikrishnah; Pardue, John H

    2013-12-15

    MC252 oil:sand aggregates, termed surface residue balls (SRBs), were sampled for physical, chemical and microbial characteristics from different tidal zones on a coastal headland beach in Louisiana, USA. Supratidal SRBs were smaller, had low moisture content, and salinities that were <2 ppt. Intertidal SRBs were hypersaline and had higher N and sulfate concentrations, consistent with regular tidal inundation. Crude oil components were highest in the intertidal "oil mat" SRBs with C1- and C2-phenanthrenes, C2- and C3-dibenzothiophenes comprising the majority of the PAH concentrations. In the other SRB categories, PAHs and alkanes were depleted and profiles were skewed toward higher molecular weight compounds. Oxygen microelectrode measurements demonstrated that saturated O2 is present immediately after wetting, but O2 consumption in the interior of the aggregate occurs after a few days. Microbial populations varied with position on the beach but sequences similar to known PAH-degrading taxa (Mycobacterium sp. and Stenotrophomonas sp.) were observed.

  2. 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.

  3. Distribution of natural and anthropogenic radionuclides in beach sand samples from Mediterranean Coast of Turkey

    Science.gov (United States)

    Özmen, S. F.; Cesur, A.; Boztosun, I.; Yavuz, M.

    2014-10-01

    Following Fukushima Dai-ichi Nuclear Power Plant accident, a huge amount of radionuclides were released in atmosphere and ocean. It's impact on the environment is of great concern to the good of the public at large. In this regard environmental radioactivity monitoring such as external dose rate and radioactivity measurements in environmental samples has been carried out. For this purpose, several beach sand samples were collected from south coast of the Turkey in September 2011 and radioactivity concentrations of 226Ra (238U), 228Ac (232Th), 40K, 134Cs and 137Cs were determined by gamma spectrometry using a high-purity Germanium detector. The measured activity concentrations in beach sand samples ranged from 4.0±0.5 to 21.5±1.8 Bq/kg, 1.8±0.4 to 27.9±2.4 Bq/kg, 19.0±2.2 to 590.3±28.6 Bq/kg and 0.1±0.0 to 1.0±0.1 Bq/kg for 226Ra, 232Th, 40K and 137Cs, respectively. However there was no sign of 134Cs in the sample spectrum after Fukushima Dai-ichi Nuclear Power Plant accident. Hence we can safely conclude that there was no significant material transfer from Fukushima to Turkey. The other activities are in good agreement with the published results of neighboring areas. The absorbed gamma dose rate (D) and the annual effective dose (AED) of beach sand samples were below the world wide average implying that the radiation hazard is insignificant. The data presented in this study would also be very useful to determine the possible future effects of the nuclear power plant to the environment.

  4. Disponibilidad de arena para el refulado de las playas de Miramar y Chapadmalal, Argentina Sand availability for nourishment of the Miramar and Chapadmalal beaches, Argentina

    Directory of Open Access Journals (Sweden)

    FI Isla

    2003-09-01

    and quality of the sand as a source for the replacement of the Miramar and Chapadamalal beaches were analyzed By the mean of a side-scan sonar surveys and drag samples. Nourishment and recurrence factors were estimated in relation to the grain-size distribution on these beaches. Present near-shore beaches are composed of fine sand and extend to a depth of 10-15 m. Farther offshore there are indurated silts extending as submerged platforms to a depth of 20 m. There is another sandy bottom at a lower depth that is dominated by sand ribbons oriented toward the NE. Unfortunately, these sands are too fine and therefore considered economically unsuitable for the replacement of the Miramar and Chapadmalal beaches.

  5. The use of natural sand from lampusatu beach, kabupatenmerauke, papua for mixed asphalt concrete

    Science.gov (United States)

    Huwae, D. D. M.; Parera, L. R.; Alpius; Tanijaya, J.

    2017-05-01

    The natural sand from LampuSatu Beach, KabupatenMerauke, Papua, is often used as building material by local people. This research aims to test the use of this natural sand for mixed asphalt concrete. Asphalt Concrete Wearing Course (AC-WC) with bitumen penetration 60/70 and variations of asphalt content 5%, 6%, 7%, 8% and 9% are used in this research. Testing result shows the stability 1372.17 kg, VIM 3.95%, VMA 16.81%, Flow 4.14 mm, and MQ 332.89 kg/mm. It has fulfilled the standard requirements set by Indonesian Director General for Highways. The percentage of Optimum Asphalt Content (OAC) is 7% and the Index of Retained Strength (IRS) is 107.84% (≥ 75%). These indicate that the mixture can fulfill the Stability and Marshall Immersion Test.

  6. Natural and human controls of the Holocene evolution of the beach, aeolian sand and dunes of Caesarea (Israel)

    Science.gov (United States)

    Roskin, J.; Sivan, D.; Shtienberg, G.; Roskin, E.; Porat, N.; Bookman, R.

    2015-12-01

    The study focuses on the Holocene appearance, chronology and drivers of beach sand deposition and inland aeolian sand transport around the Roman-Byzantine ruins of Caesarea, Israel. Beach sand, sand sheets, nebkha, linear and transverse dunes as well as parabolic and transverse interdunes along two transects were sampled in the current study down to their substrate. Sixteen new optically stimulated luminescence ages cluster at ∼5.9-3.3 ka, ∼1.2-1.1 ka (800-900 AD) and ∼190-120 years ago (1825-1895 AD) indicating times of middle and late Holocene sand sheet depositions and historical dune stabilization. The first age cluster indicates that beach sand accumulated when rates of global sea level rise declined around 6-5 ka. Until ∼4 ka sand sheets encroached up to 2.5 km inland. Historical and archaeological evidence points to sand mobilization since the first century AD. Sand sheets dating to 1.2-1.1 ka, coevally found throughout the dunefield represent sand stabilization due to vegetation reestablishment attributed to gradual and fluctuating decline in human activity from the middle Early Islamic period until the 10th century. Historical and chronological evidence of the existence of transverse and coppice dunes from the 19th century suggest that dunes only formed in the last few centuries. The study illustrates the initial role of natural processes, in this case decline in global sea level rise and the primary and later role of fluctuating human activity upon coastal sand mobility. The study distinguishes between sand sheets and dunes and portrays them as sensors of environmental changes.

  7. Sediment characteristics and microbiological contamination of beach sand - A case-study in the archipelago of Madeira.

    Science.gov (United States)

    Abreu, Roberto; Figueira, Celso; Romão, Daniela; Brandão, João; Freitas, M Conceição; Andrade, César; Calado, Graça; Ferreira, Carmen; Campos, Ana; Prada, Susana

    2016-12-15

    Beach sand can harbour pathogenic and opportunistic microorganisms, as well as faecal indicator bacteria that influence directly the bathing water quality. Pathogenic and opportunistic microorganisms often raise concern of exposure during beach related recreational activities. In this work, three different types of sandy beaches (natural basaltic, natural calcareous and artificial calcareous) of the Archipelago of Madeira (Portugal) were sampled for bacterial and fungal contaminants and grain size distribution, during four years (2010-2013). Following an extreme weather event in 2010, the faecal indicator bacteria levels spiked, returning to base levels shortly thereafter. The same phenomenon occurred with fungi, where potentially pathogenic fungi were the dominant group. Yeast-like fungi and dermatophytes were, however, mainly associated to months of higher usage by recreational users. Statistical analysis showed higher contamination of sediment in artificial beaches compared to natural beaches and granulometry and chemical composition of sand did not influence in the microbial loads. Instead, bather density and the influence of coastal protection structures needed to maintain the volume of artificial beach sand regarding the removal potential of wave induced currents are obvious influencing factors. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Occurrence of microplastics in the beach sand of the Chinese inner sea: the Bohai Sea.

    Science.gov (United States)

    Yu, Xubiao; Peng, Jinping; Wang, Jundong; Wang, Kan; Bao, Shaowu

    2016-07-01

    The occurrence of microplastics in the beach sand of the Bohai Sea was investigated for the first time. The Bohai Sea is the largest Chinese inner sea and its coastal region is one of the most densely urbanized and industrialized zones of China. Samples from three costal sites (i.e., Bijianshan, Xingcheng and Dongdaihe) were collected, quantified and identified for microplastic analysis. Effects of sample depth and tourism activity were investigated. Surface samples (2 cm) contained higher microplastic concentrations than deep samples (20 cm). Samples from the bathing beach exhibited higher microplastic concentrations than the non-bathing beach, suggesting the direct contribution of microplastics from tourism activity. Of eight types of microplastics that were found, PEVA (polyethylene vinyl acetate), LDPE (light density polyethylene) and PS (polystyrene) were the largest in abundances. Moreover, the non-plastic items from samples were analyzed and results revealed that the majority abundance of the observed non-plastics were viscose cellulose fibers. Further studies are required to evaluate the environmental hazards of microplastics, especially as they may "act as a contaminant transporter" to the Bohai Sea ecosystem.

  9. The Effect of Sand Particle Size on the Burrowing Ability of the Beach Mysid Gastrosaccus psammodytes Tattersall

    Science.gov (United States)

    Nel, R.; McLachlan, A.; Winter, D.

    1999-05-01

    Laboratory studies on the burrowing rates of the mysid shrimp, Gastrosaccus psammodytes , in a series of well-sorted sediments, determined whether (1) burial times were dependent on grain size and (2) if natural population distribution may be influenced by grain size on beaches. Burial times were tested in nine well-sorted sediments with grain size ranging from 90 to 2000μm. Large individuals (i.e. gravid females) were used. G. psammodytes burrowed fastest in 125-1000μm sand with mean burial times less than 1·6s. Burial time increased to approximately 2s in 90-125μm sand. G. psammodytes could not burrow in grain sizes coarser than 1000μm. G. psammodytes has been reported to occur on beaches with grain sizes ranging from 90 to 500μm but are uncommon on beaches with coarser sand. It appears that population distribution may be influenced by grain size that is probably not related to the animals' burial time ability, but rather their inability to burrow completely into coarse sand. Indirectly, grain size may also influence the morphodynamic state of a beach and therefore food availability since coarse-grained beaches tend to be reflective with little surf production.

  10. Gamma radiation measurement in select sand samples from Camburi beach - Vitoria, Espirito Santo, Brazil: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Livia F.; Pecequilo, Brigitte R.S.; Aquino, Reginaldo R., E-mail: lfbarros@ipen.b, E-mail: brigitte@ipen.b, E-mail: raquino@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The variation of natural radioactivity along the surface of the beach sands of Camburi, located in Vitoria, capital of Espirito Santo, southeastern Brazil, was determined from the contents of {sup 226}Ra, {sup 232}Th and {sup 40}K. Eleven collecting points was selected along all the 6 km extension of the Camburi beach. Sand samples collected from all established points on January 2011 were dried and sealed in standard 100 mL polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the {sup 238}U and {sup 232}Th series. The {sup 226}Ra concentration was determined from the weighted average concentrations of {sup 214}Pb and {sup 214}Bi. The {sup 232}Th concentration was determined from the weighted average concentrations of {sup 228}Ac, {sup 212}Pb and {sup 212}Bi and the {sup 40}K from its single gamma transition. Preliminary results show activity concentrations varying from 5 Bq.kg{sup -1} to {sup 222} Bq.kg{sup -1} for {sup 226}Ra and from 14 Bq.kg{sup -1} to 1074 Bq.kg{sup -'}1 for {sup 232}Th, both with the highest values for Camburi South and Central. For {sup 40}K, the activity concentrations ranged from 14 Bq.kg{sup -1} to 179 Bq.kg{sup -1} and the highest values were obtained for Camburi South. (author)

  11. Risk Assessment for Children Exposed to Beach Sands Impacted by Oil Spill Chemicals.

    Science.gov (United States)

    Black, Jennifer C; Welday, Jennifer N; Buckley, Brian; Ferguson, Alesia; Gurian, Patrick L; Mena, Kristina D; Yang, Ill; McCandlish, Elizabeth; Solo-Gabriele, Helena M

    2016-08-27

    Due to changes in the drilling industry, oil spills are impacting large expanses of coastlines, thereby increasing the potential for people to come in contact with oil spill chemicals. The objective of this manuscript was to evaluate the health risk to children who potentially contact beach sands impacted by oil spill chemicals from the Deepwater Horizon disaster. To identify chemicals of concern, the U.S. Environmental Protection Agency's (EPA's) monitoring data collected during and immediately after the spill were evaluated. This dataset was supplemented with measurements from beach sands and tar balls collected five years after the spill. Of interest is that metals in the sediments were observed at similar levels between the two sampling periods; some differences were observed for metals levels in tar balls. Although PAHs were not observed five years later, there is evidence of weathered-oil oxidative by-products. Comparing chemical concentration data to baseline soil risk levels, three metals (As, Ba, and V) and four PAHs (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and dibenz[a,h]anthracene) were found to exceed guideline levels prompting a risk assessment. For acute or sub-chronic exposures, hazard quotients, computed by estimating average expected contact behavior, showed no adverse potential health effects. For cancer, computations using 95% upper confidence limits for contaminant concentrations showed extremely low increased risk in the 10(-6) range for oral and dermal exposure from arsenic in sediments and from dermal exposure from benzo[a]pyrene and benz[a]anthracene in weathered oil. Overall, results suggest that health risks are extremely low, given the limitations of available data. Limitations of this study are associated with the lack of toxicological data for dispersants and oil-spill degradation products. We also recommend studies to collect quantitative information about children's beach play habits, which are necessary to more

  12. Risk Assessment for Children Exposed to Beach Sands Impacted by Oil Spill Chemicals

    Directory of Open Access Journals (Sweden)

    Jennifer C. Black

    2016-08-01

    Full Text Available Due to changes in the drilling industry, oil spills are impacting large expanses of coastlines, thereby increasing the potential for people to come in contact with oil spill chemicals. The objective of this manuscript was to evaluate the health risk to children who potentially contact beach sands impacted by oil spill chemicals from the Deepwater Horizon disaster. To identify chemicals of concern, the U.S. Environmental Protection Agency’s (EPA’s monitoring data collected during and immediately after the spill were evaluated. This dataset was supplemented with measurements from beach sands and tar balls collected five years after the spill. Of interest is that metals in the sediments were observed at similar levels between the two sampling periods; some differences were observed for metals levels in tar balls. Although PAHs were not observed five years later, there is evidence of weathered-oil oxidative by-products. Comparing chemical concentration data to baseline soil risk levels, three metals (As, Ba, and V and four PAHs (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and dibenz[a,h]anthracene were found to exceed guideline levels prompting a risk assessment. For acute or sub-chronic exposures, hazard quotients, computed by estimating average expected contact behavior, showed no adverse potential health effects. For cancer, computations using 95% upper confidence limits for contaminant concentrations showed extremely low increased risk in the 10−6 range for oral and dermal exposure from arsenic in sediments and from dermal exposure from benzo[a]pyrene and benz[a]anthracene in weathered oil. Overall, results suggest that health risks are extremely low, given the limitations of available data. Limitations of this study are associated with the lack of toxicological data for dispersants and oil-spill degradation products. We also recommend studies to collect quantitative information about children’s beach play habits, which are

  13. Heavy metal levels in dune sands from Matanzas urban resorts and Varadero beach (Cuba): Assessment of contamination and ecological risks.

    Science.gov (United States)

    Díaz Rizo, Oscar; Buzón González, Fran; Arado López, Juana O; Denis Alpízar, Otoniel

    2015-12-30

    Concentrations of chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn) and lead (Pb) in dune sands from six urban and suburban Matanzas (Cuba) resorts and Varadero beach were estimated by X-ray fluorescence analysis. Ranges of metal contents in dune sands show a strong variation across the studied locations (in mg/kg(-1)): 20-2964 for Cr, 17-183 for Ni, 17-51 for Cu, 18-88 for Zn and 5-29 for Pb. The values of contamination factors and contamination degrees how that two of the studied Matanzas's resorts (Judio and Chirry) are strongly polluted. The comparison with Sediment Quality Guidelines shows that dune sands from Judio resort represent a serious risk for humans, due to polluted Cr and Ni levels, while sands from the rest of the studied resorts, including Varadero beach, do not represent any risk for public use.

  14. Effect of sillimanite beach sand composition on mullitization and properties of Al2O3–SiO2 system

    Indian Academy of Sciences (India)

    H S Tripathi; B Mukherjee; S K Das; A Ghosh; G Banerjee

    2003-02-01

    Mullite was developed by reaction sintering of sillimanite beach sand and calcined alumina. Two varieties of sillimanite beach sand viz. S and Z having different compositions were selected. Synthesis and properties of mullite were very much dependent on the sillimanite beach sand composition. Presence of higher amount of impurities in the Z-variety of sillimanite sand favours the densification by liquid phase formation. Presence of zircon in Z-variety increases the hardness and fracture toughness. Alumina addition improves the mechanical/thermomechanical properties of the samples. Mullite retains the usual orthorhombic habit of sillimanite. Rounded to sub rounded zirconia dispersed within the mullite matrix of the sample ZA is noticed.

  15. Quantifying the effects of European beach grass on aeolian sand transport over the last century: Bodega Marine Reserve, California

    Science.gov (United States)

    Cesmat, R.; Werner, S.; Smith, M. E.; Riedel, T.; Best, R.; Olyarnik, S.

    2012-12-01

    Introduction of European beach grass (Ammophila arenaria) to coastal dune systems of western North America induced significant changes to the transport and storage of sediment, and consequently the nesting habitat of the western snowy plover (Charadrius alexandrinus nivosus). At the Bodega Marine Reserve and Sonoma Coast State Park, Ammophila was introduced within the ~0.5 km2 dune area in the 1920's to limit the flux of sand through Bodega Harbor and agricultural land. To assess the potential impact of restoration efforts (Ammophila removal) on aeolian sediment flux, we measured sediment flux as a function of wind speeds and ground cover, and used these measurements to parameterize a spatial model for historical sand deposition Fine- to coarse-grained lithic to sub-lithic sand is delivered to the Bodega dune system from Salmon Creek beach, the down-shore terminus of a littoral system fed by the 3846 km2 Russian River catchment, several small (Littoral sediment traverses the 1.8 km wide dune system from NW to SE via aeolian transport. Ammophila colonization occurred initially adjacent to the shoreface, inducing deposition of a ~10 meter-high foredune and has subsequently encroached the ~0.5 km2 region between the foredune and Bodega Harbor. Comparison of historical topographic maps via raster subtraction indicates rapid construction of both the foredune and a ~15 meter-high transverse dune (Gaffney ridge) at the edge of the planted region. An average accumulation rate of ~4,000 m3/yr is indicated within the study swath by the preserved sediment volumes. Within the modern dune system, unvegetated areas exhibit 2-3 meter wavelength, ~1/2 meter amplitude mega-ripples, and the uppermost 2-10 cm consists of coarse-sand to granule-sized armor layer. In contrast, grain-sizes in vegetated areas are largely vertically homogenous. Open areas are typically 2-8 meters lower than adjacent vegetated areas, and show evidence for net lowering of the land surface (i.e., exposed

  16. Sand of Colombian beaches as low cost thermoluminescent dosimeter for radiotherapy title

    Energy Technology Data Exchange (ETDEWEB)

    Cogollo P, R.; Ricaurte A, D.; Alvarino B, G., E-mail: rrcogollo@sinu.unicordoba.edu.co [University of Cordoba, Materials and Applied Physics Group, Carrera 6 No. 76-103, Monteria, Cordoba (Colombia)

    2013-10-01

    This paper describes the thermoluminescent characteristics of the sand coming from Colombian beaches (Covenas and Monitos), for its use as dosimeter in therapeutic dose. The selected samples, annealed at 400 C per 1 hour, were irradiated under different doses using a unity of {sup 60}Co Theratron 780 C on air at room temperature. The reading was carried out in a Harshaw TLD 4500. The main dosimetric properties of the material (glow curve, response reproducibility, reuse, linearity and thermal decay) have been in detail studied. The results show a lineal response to the dose from 50 c Gy to 1000 c Gy, in the material. The studied samples of sand can be used as thermoluminescent dosimeters for applications in different fields. The importance of this work is that the sand is a natural low cost substance, available in large quantities, and can be used in clinical physics in order to make assessments about the received dose by the patient during the medical treatment. (Author)

  17. Characteristics of Iron Sand Magnetic Material from Bugel Beach, Kulon Progo, Yogyakarta

    Science.gov (United States)

    Fahmiati; Nuryono; Suyanta

    2017-02-01

    Magnetic material (MM) of iron sands from Bugel Beach, Kulon Progo, Yogyakarta has been prepared and characterized. Magnetic material was separated from iron sands using a permanent magnet followed by treating with sodium hydroxide (NaOH) solution. The magnetic material product was characterized with X-ray Fluorescence, X-ray Diffraction, Fourrier Transform Infrared spectrophotometry, and Vibrating Sample Magnetometer to determine the chemical composition, crystallinity, presence of functional groups and the magnetization, respectively. Results showed that the investigated iron sand contained magnetic materials up to 89.47% (w/w). The main composition of MM included Fe2O3, TiO2, and SiO2, with percentages of 72.6, 7.0, and 10.0%, respectively, and the functional groups of material was dominated with Fe–OH and Fe–O. Treatment with NaOH 4M and NaOH 8M increased the content of Fe2O3 and TiO2, otherwise reduced the concentration of SiO2 and contributed to the improvement of the magnetization from 42.1 to 44.3 emu/g (with 4 M NaOH) and 64.0 emu/g (with 8 M NaOH). Additionally, MM was dominated with mineral of magnetite and contained functional groups of Fe–OH and Fe–O.

  18. Effect of Low Energy Waves on the Accumulation and Transport of Fecal Indicator Bacteria in Sand and Pore Water at Freshwater Beaches.

    Science.gov (United States)

    Wu, Ming Zhi; O'Carroll, Denis M; Vogel, Laura J; Robinson, Clare E

    2017-02-24

    Elevated fecal indicator bacteria (FIB) in beach sand and pore water represent an important nonpoint source of contamination to surface waters. This study examines the physical processes governing the accumulation and distribution of FIB in a beach aquifer. Field data indicate E. coli and enterococci can be transported 1 and 2 m, respectively, below the water table. Data were used to calibrate a numerical model whereby FIB are delivered to a beach aquifer by wave-induced infiltration across the beach face. Simulations indicate FIB rapidly accumulate in a beach aquifer with FIB primarily associated with sand rather than freely residing in the pore water. Simulated transport of E. coli in a beach aquifer is complex and does not correlate with conservative tracer transport. Beaches with higher wave-induced infiltration rate and vertical infiltration velocity (i.e., beaches with higher beach slope and wave height, and lower terrestrial groundwater discharge) had greater E. coli accumulation and E. coli was transported deeper below the beach face. For certain beach conditions, the amount of FIB accumulated in sand over 5-6 days was found to be sufficient to trigger a beach advisory if eroded to surface water.

  19. Origin of amphibole-rich beach sands from Tila-Mati, Karwar, central-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Iyer, S.D.

    The pocket beach at Tila-Mati, Karwar, central west coast of India, is characterised by the occurrence of amphibole-rich (chiefly tremolite-actinolite) coarse sand in the zone of minimal impact of waves and currents. In the total sediment, grain...

  20. Predicting suspended sand concentration profiles on a macro-tidal beach

    Science.gov (United States)

    Vincent, C. E.; Osborne, P. D.

    1995-11-01

    Suspended sand concentration profiles were measured using acoustic backscatter on a macro-tidal beach at Whitsand Bay, Cornwall, U.K. over a period of 9 days when wave heights were generally between 0.75 m and 0.25 m and wave periods from 5 to 7 s. Average profiles over periods of 6 or 14 min were dominantly of the vortex type, reflecting the importance of steep bedforms in maintaining the suspended sand profile. Bedform dimensions spanned the range between those occurring under regular laboratory waves and those observed under field conditions [ Nielsen, 1981 ( Journal of Geophysical Research, 86, 6467-6472)]. The concentration profiles can be defined by a mixing height zh and a near-bed concentration C0, in this case the concentration at 2 cm above the sea bed. There was considerable variability in zh resulting from the irregular spacing of the bedforms [Osborne and Vincent, 1994 ( Marine Geology, 115, 207-226)], but zh showed a significant dependence on the bed friction defined through the Shields number θ' max based on the skin friction. The variation in the near bed concentration was observed to be only weakly dependent on the excess skin friction at the bed, supporting earlier observations that the resuspension parameter γ 0 [ Smith and McLean, 1977 (in: Bottom turbulence, Elsevier, New York, pp. 123-152)] decreased rapidly as the excess skin friction increased. We conclude that a mixing height given by zh = 2.2 exp (3.05θ' max) and a reference concentration at 2 cm defined using γ 0 = 5.25 × 10 -6 (θ' max) -1.64 was appropriate to predict the mean vertical suspension profile on this macro-tidal beach for a wide range of low wave conditions.

  1. Coating of Sulfonic Silica onto Magnetite from Marina Beach Iron sand, Semarang, Indonesia

    Science.gov (United States)

    Azmiyawati, C.; Suyati, L.; Taslimah; Anggraeni, R. D.

    2017-02-01

    The mineral iron oxide is the main component of sand iron that are abundant in nature. Mineral iron oxide not yet widely applied into more useful products. The main component of iron ore is magnetite. Magnetite can be used as a basic ingredient in the manufacture of magnetite-modified silica adsorbent sulfonate. In this research, the adsorbent made from sulfonic functionalized silica-coated magnetic particle has been successfully produced, with the magnetite was obtained from iron sand at Marina Beach, Semarang Indonesia. This adsorbent was then used as a metal ion preconcentration media. From the research that it was found that the sulfonic has been bound to the silica marked by the emergence of element S on EDX. Whilst, the evidence that silica has coated on the magnetite could be seen from the SEM images which showed the morphology of sulfonic functionalized silica-coated magnetic particles were larger than the sulfonic functionalized silica without magnetite. From the DSC results showed that the addition of magnetite on sulfonic functionalized silica did not change the heat resistance of the sulfonic functionalized silica. Based on the XRD patterns show that magnetite sulfonate silica was formed.

  2. Offshore Sand Resource Needs, Data Availability and Revaluation, and Beach Nourishment Projects in North Carolina

    Science.gov (United States)

    Conery, I.; Walsh, J. P.

    2016-12-01

    Storms and sea-level rise continue to impact the dynamic coastlines of North Carolina. Since the coastal region is economically critical to the state and yields numerous ecosystem services, many towns have planned beach nourishment projects. However, offshore sands compatible for nourishment are limited, and project costs fluctuate with borrow source proximity to the shoreline. Hurricane Sandy (2012) caused high water levels and waves resulting in localized overwash and erosion in the northeastern part of NC. In response, to effectively meet the rising nourishment demands for recovery after future storm events and for long-term resiliency, the Bureau of Ocean Energy Management (BOEM) recognized the need to compile and consolidate all geophysical and geologic information in federal waters (3-8 nm) along the East Coast states. A GIS database was created for NC using bathymetric, seismic reflection, sediment and other relevant data from federal, state and private entities. Information will be accessible to the public, coastal planners and managers to allow for informed decision-making and cost-effective project planning. Priority regions for seismic and core collection were determined based on data gaps and needs across the state. In addition, potential sand resource thickness and volume in northeastern NC were revaluated using comparisons of several overlapping datasets. Shoreline volume losses were calculated using long-term erosion rates and compared to historic and future nourishment projects. Finally, tourism-based revenue by town was evaluated and related to short and long-term nourishment costs.

  3. The cumulative effects of using fine particles and cyanobacteria for rehabilitation of disturbed active sand dunes

    Science.gov (United States)

    Zaady, Eli; Katra, Itzhak; Barkai, Daniel; Knoll, Yaakov; Sarig, Shlomo

    2016-04-01

    One of the main problems in desertified lands worldwide is active wind-borne sand dunes, which lead to covering of fertile soils and agricultural fields. In regions with more than 100 mm of annual rainfall, sand dunes may be naturally stabilized by biocrusts (biological soil crusts). One of the main restraints of biocrust development is the typical lack of fine particles in sand dunes. Our study investigated the combined application of fine particles [coal fly-ash <100 micrometer] and bio-inoculant of filamentous cyanobacteria, isolated from nearby natural stabilized sand dunes, on the soil surface of active sands for increasing resistance to wind erosion. Boundary-layer wind tunnel experiments were conducted in experimental plots within a greenhouse for examining the effects of adding coal fly-ash and bio-inoculant to active sands. The biocrust development was evaluated via several physical and bio-physiological variables. In all the physical measurements and the bio-physiological variables, the treatment of "sand+inoculum+coal fly-ash" showed significant differences from the "sand-control". The combination led to the best results of surface stabilization in boundary-layer wind tunnel experiments, with the lowest sand fluxes. The filamentous cyanobacteria use the fine particles of the coal fly-ash as bridges for growing toward and adhering to the large sand particles. The cumulative effects of biocrusts and coal fly-ash enhance soil surface stabilization and may allow long-term sustainability.

  4. Geochemical behavior of rare-earth elements and other major and minor elements in sound-producing and silent beach sands in Japan

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The major element composition of sound-producing sand is reported together with rare-earth elements (REE) and other selected elements for the first time. Rare-earth element concentrations in beach sands from Miyagi and Tottori in Japan were determined by induction-coupled, argon-plasma spectrometry (ICP-MS) to characterize the REE of sound-producing and silent sands relative to the parental rocks. Sound-producing sand beaches are very common and all over in Japan: five beaches in Miyagi and 2 in Tottori are selected with other silent sand beaches in the areas. Both sound-producing sand and silent sand samples from Miyagi and Tottori contain more than 60wt% of SiO2 and are composed mainly of quartz and feldspar. Miyagi sand samples are characterized by light REE enrichment and flat chondrite-normalized patterns that are similar to those of local source sandstone. However, all sand samples from Miyatojima in Miyagi show positive Eu anomalies, a characteristic feature not shown in other sand samples from Miyagi. Tottori sand samples also are characterized by high REE contents and remarkable positive Eu anomalies. The sands containing lower REE contents are due to high quartz and feldspar contents. Miyatojima sand samples and Tottori sand samples have high REE contents and show remarkable positive Eu anomalies due to the presence of feldspar.The best results are obtained using all of the geological methods and the Principal Component Analysis (PCA) as a measure of the similarity between sound-producing sand and silent sand. The difference between sound-producing sand and silent sand is obtained from the PCA results.

  5. Biological control of infective larvae of Ancylostoma spp. in beach sand.

    Science.gov (United States)

    De Mello, Ingrid Ney Kramer; Braga, Fabio R; Monteiro, Thalita S Avelar; Freitas, Leandro G; Araujo, Juliana M; Soares, Filippe E Freitas; Araújo, Jackson V

    2014-01-01

    Geohelminths are parasites that stand out for their prevalence and wide distribution, depending on the soil for their transmission. The aim of this work was to evaluate the predatory capacity of the fungal isolate of the genus Duddingtonia (CG768) on third stage larvae (L3) of Ancylostoma spp. in beach sand under laboratory conditions. In the assay A five treatment groups and 1 control group were formed. The treatment groups contained 5000, 10,000, 15,000, 20,000 or 25,000 chlamydospores of the fungal isolate and 1000 Ancylostoma spp. L3 in pots containing 30g of sand. The control group (without fungus) contained only 1000 Ancylostoma spp. L3 and distilled water in pots with 30g of sand. Evidence of predatory activity was observed at the end of 15 days, where we observed the following percentages of reduction of L3: Group 1 (4.5%); Group 2 (24.5%); Group 3 (59.2%); Group 4 (58.8%); Group 5 (63%). However, difference was noted (p<0.01) only at concentrations 15,000, 20,000 and 25,000 in relation to control group. In the assay B two groups were formed in Petri dishes of 9cm in diameter containing agar water 2% medium. In the treated group, each Petri dish contained 500 Ancylostoma spp. L3 and 5g of sand containing the isolate CG 768 at a concentration of 25,000 chlamydospores/g of sand, and the control group (without fungus) contained only 500 L3. At the end of 7 days the non-predation L3 of Petri dishes using the method of Baermann were recovered. Difference (p<0.01) between groups on reducing the average number of Ancylostoma spp. L3 (percent reduction of 84%) was observed. The results of this study confirm earlier work on the efficiency of the Duddingtonia genus in the control of Ancylostoma spp. infective larvae. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  6. Coastline sand waves on a low-energy beach at El Puntal spit, Spain: Linear stability analysis

    Science.gov (United States)

    MedellíN, G.; FalquéS, A.; Medina, R.; GonzáLez, M.

    2009-03-01

    Shoreline sand waves of approximately 125-150 m of wavelength and ≈15 m of amplitude in the offshore direction (reached in a few days) are often observed at the west end of El Puntal spit, Santander, Spain. They tend to last for about 2 months and do not show an evident alongshore propagation during that time. Since wave incidence on that beach is typically very oblique, a shoreline linear stability analysis is performed to test whether those sand waves could be generated by shoreline instability. Because of the low-energy wave climate and the steep mean bathymetric profile, the predicted wavelength (100-150 m) and growth time (4-8 days) are much smaller than is typical on open ocean beaches. This provides a unique opportunity to test high-angle wave instability. Thus, the role of the instability on the growth, evolution, and subsequent destruction of the sand waves is examined. A remarkable agreement between predictions and observations regarding the wavelength and growth time is found. Furthermore, by analyzing shoreline instability for a 2 year period where sand waves sometimes occur and sometimes do not, a clear correlation is found between sand wave occurrence and predicted instability growth rate. Intriguingly, results are less satisfactory regarding alongshore migration since the model predicts some migration that is not supported by observations. However, it becomes clear that the instability caused by high-angle waves is crucial for shoreline sand wave formation at El Puntal and should be considered for any future research.

  7. Observations of coastal sediment dynamics of the Tijuana Estuary Fine Sediment Fate and Transport Demonstration Project, Imperial Beach, California

    Science.gov (United States)

    Warrick, Jonathan A.; Rosenberger, Kurt J.; Lam, Angela; Ferreiera, Joanne; Miller, Ian M.; Rippy, Meg; Svejkovsky, Jan; Mustain, Neomi

    2012-01-01

    Coastal restoration and management must address the presence, use, and transportation of fine sediment, yet little information exists on the patterns and/or processes of fine-sediment transport and deposition for these systems. To fill this information gap, a number of State of California, Federal, and private industry partners developed the Tijuana Estuary Fine Sediment Fate and Transport Demonstration Project ("Demonstration Project") with the purpose of monitoring the transport, fate, and impacts of fine sediment from beach-sediment nourishments in 2008 and 2009 near the Tijuana River estuary, Imperial Beach, California. The primary purpose of the Demonstration Project was to collect and provide information about the directions, rates, and processes of fine-sediment transport along and across a California beach and nearshore setting. To achieve these goals, the U.S. Geological Survey monitored water, beach, and seafloor properties during the 2008–2009 Demonstration Project. The project utilized sediment with ~40 percent fine sediment by mass so that the dispersal and transport of fine sediment would be easily recognizable. The purpose of this report is to present and disseminate the data collected during the physical monitoring of the Demonstration Project. These data are available online at the links noted in the "Additional Digital Information" section. Synthesis of these data and results will be provided in subsequent publications.

  8. Radiation hazards evaluation for selected sand samples from Camburi beach, Vitoria, Espirito Santo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Livia F.; Pecequilo, Brigitte R.S., E-mail: lfbarros@ipen.br, E-mail: brigitte@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In this work, a single location at Camburi beach, known to be a naturally high background region, was studied. Radiation hazards indexes and annual effective dose were evaluated from the {sup 226}Ra, {sup 232}Th and {sup 40}K sands activities concentrations. Sand samples were monthly collected during 2011, dried, sealed in standard 100 mL HPDE polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks in-growth period. The {sup 226}Ra concentration was determined from the weighted average concentrations of {sup 214}Pb and {sup 214}Bi. The {sup 232}Th concentration was determined from the weighted average concentrations of {sup 228}Ac, {sup 212}Pb and {sup 212}Bi and the {sup 4}0K from its single gamma transition. The results, considering samples gamma-rays self-attenuation, show activities concentrations in the range from 6 Bq kg{sup -1} to 39 Bq kg{sup -1} for {sup 226}Ra, 13 Bq kg{sup -1} to 161 Bq kg{sup -1} for {sup 232}Th, and 7 Bq kg{sup -1} to 65 Bq kg{sup -1} for {sup 40}K. The radium equivalent activity for the studied samples ranged from 26 Bq kg{sup -1} to 274 Bq kg{sup -}'1. The external and internal hazard indexes varied, respectively, from 0.07 to 0.74 and from 0.09 to 0.85. The annual effective dose values laid from 0.07 mSv.y{sup -1} to 0.72 mSv.y{sup -}'1. All values obtained in this work are below the radiological protection recommended limits. (author)

  9. Filler effect of fine particle sand on the compressive strength of mortar

    Science.gov (United States)

    Jaturapitakkul, Chai; Tangpagasit, Jatuphon; Songmue, Sawang; Kiattikomol, Kraiwood

    2011-04-01

    The river sand, which is a non-pozzolanic material, was ground into 3 different particle sizes. Portland cement type I was replaced by the ground river sands at 10wt%-40wt% of binder to cast mortar. Compressive strengths of mortar were investigated and the filler effect of different fine particles of sand on the compressive strength of mortar was evaluated. The results show that the compressive strength of mortar contributed from the filler effect of smaller particles is higher than that of the coarser ones. The difference in compressive strength of mortar tends to be greater as the difference in ground river sand fineness increases. The results also suggest that ASTM C618 specification is not practically suitable for specifying pozzolan in concrete since the strength activity index of mortar containing ground river sand (high crystalline phase) with 33.8wt% of particles retained on a 45-μm sieve can pass the strength requirement.

  10. Use of Crushed Granite Fine as Replacement to River Sand in Concrete Production

    Directory of Open Access Journals (Sweden)

    Manasseh JOEL

    2010-12-01

    Full Text Available The suitability of Crushed granite fine (CGF to replace river sand in concrete production for use in rigid pavement was investigated. Slump, compressive and indirect tensile strength tests were performed on fresh and hardened concrete.28 days Peak compressive and indirect tensile strength values of 40.70N/mm2 and 2.30N/mm2 respectively was obtained, with the partial replacement of river sand with 20% CGF, as against values of 35.00N/mm2 and 1.75N/mm2, obtained with the use of river sand as fine aggregate. Based on economic analysis and results of tests, river sand replaced with 20% CGF is recommended for use in the production of concrete for use in rigid pavement. Conservation of river sand in addition to better ways of disposing wastes from the quarry sites are some of the merits of using CGF.

  11. Assessment of natural radioactivity and gamma-ray dose in monazite rich black Sand Beach of Penang Island, Malaysia.

    Science.gov (United States)

    Shuaibu, Hauwau Kulu; Khandaker, Mayeen Uddin; Alrefae, Tareq; Bradley, D A

    2017-06-15

    Activity concentrations of primordial radionuclides in sand samples collected from the coastal beaches surrounding Penang Island have been measured using conventional γ-ray spectrometry, while in-situ γ-ray doses have been measured through use of a portable radiation survey meter. The mean activity concentrations for (226)Ra, (232)Th and (40)K at different locations were found to be less than the world average values, while the Miami Bay values for (226)Ra and (232)Th were found to be greater, at 1023±47 and 2086±96Bqkg(̶ 1) respectively. The main contributor to radionuclide enrichment in Miami Bay is the presence of monazite-rich black sands. The measured data were compared against literature values and also recommended limits set by the relevant international bodies. With the exception of Miami Bay, considered an elevated background radiation area that would benefit from regular monitoring, Penang island beach sands typically pose no significant radiological risk to the local populace and tourists visiting the leisure beaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Experimental Study of the Possibility to Make a Mortar with Ternary Sand (Natural and Artificial Fine Aggregates)

    Science.gov (United States)

    Baali, L.; Naceri, A.; Rahmouni, Z.; Mehidi, M. W. Noui

    This experimental study investigates the possibility to make a mortar with a ternary sand (natural and artificial fine aggregates). This method is utilized to correct the particle size distribution of various sands used in mortar. For this investigation, three sands have been used: a dune sand (DS), a slag sand (SS), and brick sand (BS) at different proportions in mortar. After crushing, the artificial fine aggregate (blast furnace slag and waste brick fine aggregate) was sifted in order to use it as fine aggregate. The effect of the quality and grain size distribution of natural fine aggregate (i.e., DS) and artificial fine aggregates (i.e., SS and BS) on the physical properties of ternary sand confected (density, porosity, fineness modulus, equivalent sand, particle size distribution, water absorption) and properties of fresh and hardened mortar were analysed. In the same way for this study, the physical properties and chemical compositions of DS, SS, BS and cement were investigated. The results obtained show that the mechanical strength on mortar depends of the nature and particle size distribution of sand studied. The reuse of this recycled material (slag blast furnace and waste brick) in the industry would contribute to the protection of the environment. This study shows the potential of this method to make mortar with ternary sand (natural and artificial fine aggreagates) in order to improve the physical properties of sand. Utilising natural and artificial fine aggregates to produce quality mortar should yield significant environmental benefits.

  13. Detection of Salmonella enterica Serovar Montevideo and Newport in Free-ranging Sea Turtles and Beach Sand in the Caribbean and Persistence in Sand and Seawater Microcosms.

    Science.gov (United States)

    Ives, A-K; Antaki, E; Stewart, K; Francis, S; Jay-Russell, M T; Sithole, F; Kearney, M T; Griffin, M J; Soto, E

    2017-09-01

    Salmonellae are Gram-negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non-typhoidal Salmonella enterica in the nesting and foraging populations of sea turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting leatherback sea turtles compared with foraging green and hawksbill sea turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 leatherback sea turtle samples. Salmonella DNA was detected in one hawksbill turtle, but viable isolates were not recovered from any hawksbill sea turtles. No Salmonella was detected in green sea turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive-element palindromic PCR (rep-PCR) fingerprint analysis and pulsed-field gel electrophoresis of the 2014 isolates from turtles and sand as well as archived Salmonella isolates recovered from leatherback sea turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory-controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32 days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free-ranging marine reptiles and the potential

  14. Study on Strength of Concrete Using Robo Sand as a Partial Replacement of Fine Aggregate

    Directory of Open Access Journals (Sweden)

    S.Rukmangadhara Rao,

    2015-12-01

    Full Text Available Robo sand is one of the most used among such materials to replace river sand, which can be used as an alternative to fine aggregate in concrete. In the present investigation workability and strength of concrete was evaluated by replacement of natural sand by Robo sand in proportions of 0%, 50%, 75%, and 100% is studied for M25and M35grade concrete cubes, cylinders and prisms. Slump cone method is taken for finding workability. For strength parameters for each grade of concrete Cubes, Cylinders and Prisms were casted and tested at the age of 7 and 28 days. In this present experimental study on concrete having grades of M25 and M35 are prepared by replacing natural sand by Robo sand. Concrete specimens were tested for evaluation of compressive strength and water absorption.

  15. Assessment of Ni, Cu, Zn and Pb levels in beach and dune sands from Havana resorts, Cuba.

    Science.gov (United States)

    Díaz Rizo, Oscar; Buzón González, Fran; Arado López, Juana O

    2015-11-15

    Concentrations of nickel (Ni), copper (Cu), zinc (Zn) and lead (Pb) in beach and dune sands from thirteen Havana (Cuba) resorts were estimated by X-ray fluorescence analysis. Determined mean metal contents (in mg·kg(-1)) in beach sand samples were 28±12 for Ni, 35±12 for Cu, 31±11 for Zn and 6.0±1.8 for Pb, while for dune sands were 30±15, 38±22, 37±15 and 6.8±2.9, respectively. Metal-to-iron normalization shows moderately severe and severe enrichment by Cu. The comparison with sediment quality guidelines shows that dune sands from various resorts must be considered as heavily polluted by Cu and Ni. Almost in every resort, the Ni and Cu contents exceed their corresponding TEL values and, in some resorts, the Ni PEL value. The comparison with a Havana topsoil study indicates the possible Ni and Cu natural origin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. FORTNIGHTLY MOLTING AND REPRODUCTIVE CYCLES IN THE SAND-BEACH ISOPOD, EXCIROLANA CHILTONI.

    Science.gov (United States)

    Klapow, L A

    1972-12-01

    1. The isopod, Excirolana chiltoni is found buried in the sand in a narrow zonal band on the high intertidal beach during low tide and emerges only during high tide to swim and forage in the wave wash. The position of the zonal band during low tides bears a consultant relationship to the level of the water line during the preceding high tide. Because of this relationship the isopod zone moves up and down the beach on a fortnightly schedule which corresponds to the semi-monthly variation in tide amplitudes (the spring-neap cycle). 2. Excirolana chiltoni stores considerable quantities of mineral prior to ecdysis in localized concretions of the integument (dermoliths). 3. Molting takes place in two steps. First the posterior portion of the isopod including the abdomen and last 3 thoracic segments is cast which is followed by the casting of the anterior portion of the animal. Isopods which are in the process of molting can be easily recognized since the newly exposed posterior exoskeleton is fully expanded before the anterior cast is made. 4. The development of dermoliths and the relative abundance of half-molted individuals were used to determine the frequence of molting in a field population which was sampled at 2 day intervals for a period of a month. These data indicate that molting is largely if not entirely restricted to the weeks preceding new or full moon when the amplitude of the tides is increasing. 5. Excirolana chiltoni also shows fortnightly periodicities in feeding and the degree to which it is infested with external parasites. 6. Indirect evidence suggests that the release of young also follows a fortnightly schedule and is most intense at the same phase of the spring-neap cycle that the population molts. Females retain their broods internally and might therefore be capable of controlling the timing of birth with considerable precision. 7. Synchronous molting was not as apparent in populations which were held under non-tidal conditions in the laboratory

  17. Assessment of offshore New Jersey sources of Beach replenishment sand by diversified application of geologic and geophysical methods

    Science.gov (United States)

    Waldner, J.S.; Hall, D.W.; Uptegrove, J.; Sheridan, R.E.; Ashley, G.M.; Esker, D.

    1999-01-01

    Beach replenishment serves the dual purpose of maintaining a source of tourism and recreation while protecting life and property. For New Jersey, sources for beach sand supply are increasingly found offshore. To meet present and future needs, geologic and geophysical techniques can be used to improve the identification, volume estimation, and determination of suitability, thereby making the mining and managing of this resource more effective. Current research has improved both data collection and interpretation of seismic surveys and vibracore analysis for projects investigating sand ridges offshore of New Jersey. The New Jersey Geological Survey in cooperation with Rutgers University is evaluating the capabilities of digital seismic data (in addition to analog data) to analyze sand ridges. The printing density of analog systems limits the dynamic range to about 24 dB. Digital acquisition systems with dynamic ranges above 100 dB can permit enhanced seismic profiles by trace static correction, deconvolution, automatic gain scaling, horizontal stacking and digital filtering. Problems common to analog data, such as wave-motion effects of surface sources, water-bottom reverberation, and bubble-pulse-width can be addressed by processing. More than 160 line miles of digital high-resolution continuous profiling seismic data have been collected at sand ridges off Avalon, Beach Haven, and Barnegat Inlet. Digital multichannel data collection has recently been employed to map sand resources within the Port of New York/New Jersey expanded dredge-spoil site located 3 mi offshore of Sandy Hook, New Jersey. Multichannel data processing can reduce multiples, improve signal-to-noise calculations, enable source deconvolution, and generate sediment acoustic velocities and acoustic impedance analysis. Synthetic seismograms based on empirical relationships among grain size distribution, density, and velocity from vibracores are used to calculate proxy values for density and velocity

  18. The prevalence and distribution of indicators of fecal contamination in the sand from beaches of Oran coast

    Science.gov (United States)

    Messaoui, N.; Matallah-Boutiba, A.; Boutiba, Z.

    2017-02-01

    The microbiological quality of water at public bathing beaches is regularly monitored using fecal indicator bacteria (FIB) as a surrogate for the presence of human sewage and pathogens. The common feature of all these routine screening procedures is that the primary analysis is for indicator organisms rather than the pathogens that might cause concern. Indicator organisms are bacteria such as non-specific coliforms, Escherichia coli and Pseudomonas aeruginosa that are very commonly found in the human or animal gut and which, if detected, may suggest the presence of sewage. Indicator organisms are used because even when a person is infected with more pathogenic bacteria, they will still be excreting many millions times more indicator organisms than pathogens. It is therefore reasonable to surmise that if indicator organism levels are low, then pathogen levels will be very much lower or absent. Judgments as to suitability of water for use are based on very extensive precedents and relate to the probability of any sample population of bacteria being able to be infective at a reasonable statistical level of confidence. Exposure to FIB and associated pathogens may also occur through contact with contaminated beach sand, but no standards limiting levels of microbes in sand or required monitoring program has been established. As a result, the factors affecting FIB and pathogen survival/persistence in sand remain largely unstudied. A possible contamination of the sand by bacterial communities could be a source of transmission of certain pathogenic bacteria. The goal of this study was to look for a presence of certain bacteria that could be a source of illness to swimmers and compare the different levels of contamination between beach sand and sea water in four sites along the Western Oranian coast. First analysis were made during the dry season and rainy season from December 2010 to June 2012 to estimate fecal coliforms, Pseudomonas spp and total germs levels. E.coli and

  19. Climate-change impacts on sandy-beach biota: crossing a line in the sand.

    Science.gov (United States)

    Schoeman, David S; Schlacher, Thomas A; Defeo, Omar

    2014-08-01

    Sandy ocean beaches are iconic assets that provide irreplaceable ecosystem services to society. Despite their great socioeconomic importance, beaches as ecosystems are severely under-represented in the literature on climate-change ecology. Here, we redress this imbalance by examining whether beach biota have been observed to respond to recent climate change in ways that are consistent with expectations under climate change. We base our assessments on evidence coming from case studies on beach invertebrates in South America and on sea turtles globally. Surprisingly, we find that observational evidence for climate-change responses in beach biota is more convincing for invertebrates than for highly charismatic turtles. This asymmetry is paradoxical given the better theoretical understanding of the mechanisms by which turtles are likely to respond to changes in climate. Regardless of this disparity, knowledge of the unique attributes of beach systems can complement our detection of climate-change impacts on sandy-shore invertebrates to add rigor to studies of climate-change ecology for sandy beaches. To this end, we combine theory from beach ecology and climate-change ecology to put forward a suite of predictive hypotheses regarding climate impacts on beaches and to suggest ways that these can be tested. Addressing these hypotheses could significantly advance both beach and climate-change ecology, thereby progressing understanding of how future climate change will impact coastal ecosystems more generally.

  20. Evaluation of Ra, Th, K and radium equivalent activity in sand samples from Camburi Beach, Vitoria, Espirito Santos, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Livia F.; Pecequilo, Brigitte R.S., E-mail: lfbarros@ipen.br, E-mail: brigitte@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Camburi beach, in the city of Vitoria, Espirito Santo State. Brazil, is a naturally high background region in Brazil. The beach sands contain monazite, ilmenite and other accessory minerals rich in {sup 226}Ra, {sup 23}'2Th and {sup 40}K. As these radionuclides are the main natural contributors to external exposure from gamma rays, the knowledge of the sands radioactivity content plays an important role in radiation protection. In this work, {sup 226}Ra, {sup 232}Th and {sup 40}K activities concentrations, together with the radium equivalent activity, Ra{sub eq.} were determined in some selected sand samples from a single location at Camburi beach, known for the high level of radioactivity. The sand samples collected monthly from January to December 2011, were dried and sealed in standard 100 mL HPDE polyethylene flasks and measured by high resolution gamma-spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the {sup 238}U and {sup 23}'2Th series. Preliminary results, without considering samples self-attenuation, show activities concentrations in the range from 12 {+-} 1 Bq kg{sup -1} to 1022 {+-} 30 Bq kg{sup -1} for {sup 226}Ra, 35 {+-} 1 Bq kg{sup -1} to 5731 {+-} 134 Bq kg{sup -1} for {sup 232}Th and 18 {+-} 4 Bqkg{sup -1} to 430 {+-} 21 Bq kg{sup -1} for {sup 40}K. The Ra{sub eq}, presented values ranging from 63 Bq kg{sup -1} to 9250 Bq kg{sup -1}. (author)

  1. Where Has All the Oil Gone? The use of trace metals as potential indicators of oil contamination in marine sediments and beach sands

    Science.gov (United States)

    Roeder, T. K.; Hastings, D. W.; Holzinger, C.; Playle, E.; Brooks, G.; Huettel, M. H.; Kostka, J. E.; Larson, R. A.; Flower, B. P.

    2011-12-01

    We report initial results to determine if select trace metals are effective indicators for the magnitude and spatial extent of Deep Water Horizon (DWH) oil contamination in Gulf of Mexico marine sediments and beach sands. Since crude oil is known to have elevated concentrations of nickel and vanadium, contamination can be detected even after the degradation of oil by measuring enrichment of these metals within marine sediments and beach sands. A sample of crude oil from the Macondo Prospect, source of the Deepwater Horizon (DWH) oil spill, was fully digested and analyzed by inductively coupled plasma mass spectrometry (ICP-MS) at the College of Marine Science, University of South Florida. Results indicate the crude oil is enriched in nickel, vanadium, and cobalt, with concentrations of 0.86 ppm, 2.76 ppm, and 84 ppb, respectively. With this known trace metal enrichment in DWH oil, Gulf of Mexico marine sediments from 400 and 1100m water depth near DeSoto Canyon and beach sands from Pensacola, FL were examined for enrichment of V, Ni, and Co. Both marine sediment and beach sand samples were partially digested with HNO3 before analysis via ICP-MS. With marine sediments, the visually contaminated layer at or near the surface typically exhibited an enrichment in Ni, V, and Co compared to the pristine control sediments. Vanadium and nickel enrichment in marine sediments varied from 10 to 32% and 0 to 22%, respectively. Visible contamination in beach sands was found between 20-60cm beneath the surface and, likewise, showed Ni, V, and Co enrichment up to 33%, 45%, and 100%. This data shows that enrichment of V, Ni, and Co in marine sediments and beach sands may be an effective proxy for contamination even after the degradation of oil. Marine sediments and beach sands will continue to be monitored for trace metal enrichment in an effort to assess the continuing impacts of the DWH spill on the Gulf of Mexico.

  2. Coal-sand attrition system and its importance in fine coal cleaning. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, R.K.; Zhu, Qinsheng

    1993-08-01

    It is known that ultra-fine coals are prerequisite for the deep cleaning of most US coal seams if environmental pollution arising from the use of such coals is to be minimized. Therefore, the production of finely liberated coal particles in conjunction with reduced heavy metal contaminants at low costs is desirable, if not mandatory. The liberation of intimately disseminated impurities from the coal matrix therefore, demands that the material be ground to a high degree of fineness. Similarily, some technologies for coal utilization require superfine particles (i.e., sizes less than ten microns). This implies additional costs for coal preparation plants due to the high energy and media costs associated with fine grinding operations. Besides, there are problems such as severe product contaminations due to media wear and impairment of the quality of coal. Hence, proper choice of grinding media type is important from the viewpoints of cost reduction and product quality. The use of natural quartz sand as grinding media in the comminution of industrial minerals in stirred ball mills has been indicated. The advantages of natural sand compared to steel media include low specific energy inputs, elimination of heavy metal contaminants and low media costs. In this work, the effect of rotor speed, solids concentration and feed-size are studied on four coals in conjunction with silica sand and steel shot. The results obtained are used to evaluate the suitability of silica sands as an alternative grinding media. for coal. Coal-sand and coal-steel systems are compared in terms of specific energy consumption, product fineness, media/wear contaminationanalysis and calorific values, liberation spectrum and particle shape characteristics. In general cleaner flotation concentrate was obtained from coals when they were ground with sand media. The zeta potential of coals was found to be different and lower when they ground with sand.

  3. Faecal indicator bacteria enumeration in beach sand: A comparison study of extraction methods in medium to coarse sands

    Science.gov (United States)

    Boehm, A.B.; Griffith, J.; McGee, C.; Edge, T.A.; Solo-Gabriele, H. M.; Whitman, R.; Cao, Y.; Getrich, M.; Jay, J.A.; Ferguson, D.; Goodwin, K.D.; Lee, C.M.; Madison, M.; Weisberg, S.B.

    2009-01-01

    Aims: The absence of standardized methods for quantifying faecal indicator bacteria (FIB) in sand hinders comparison of results across studies. The purpose of the study was to compare methods for extraction of faecal bacteria from sands and recommend a standardized extraction technique. Methods and Results: Twenty-two methods of extracting enterococci and Escherichia coli from sand were evaluated, including multiple permutations of hand shaking, mechanical shaking, blending, sonication, number of rinses, settling time, eluant-to-sand ratio, eluant composition, prefiltration and type of decantation. Tests were performed on sands from California, Florida and Lake Michigan. Most extraction parameters did not significantly affect bacterial enumeration. anova revealed significant effects of eluant composition and blending; with both sodium metaphosphate buffer and blending producing reduced counts. Conclusions: The simplest extraction method that produced the highest FIB recoveries consisted of 2 min of hand shaking in phosphate-buffered saline or deionized water, a 30-s settling time, one-rinse step and a 10 : 1 eluant volume to sand weight ratio. This result was consistent across the sand compositions tested in this study but could vary for other sand types. Significance and Impact of the Study: Method standardization will improve the understanding of how sands affect surface water quality. ?? 2009 The Society for Applied Microbiology.

  4. Rhizobium subbaraonis sp. nov., an endolithic bacterium isolated from beach sand.

    Science.gov (United States)

    Ramana, Ch V; Parag, B; Girija, K R; Ram, B Raghu; Ramana, V Venkata; Sasikala, Ch

    2013-02-01

    Two strains (JC85(T) and JC108) of Gram-stain-negative, motile bacteria were isolated from endolithic beach sand samples on an oligotrophic medium. Based on the 16S rRNA gene sequence analysis, both strains were identified as belonging to the genus Rhizobium. Strain JC108 had 16S rRNA gene sequence similarity of 100 % with Rhizobium pusense NRCPB10(T) and formed a cluster with this strain. Strain JC85(T) had 96.9 % 16S rRNA gene sequence similarity and was 18 % related (based on DNA-DNA hybridization) to Rhizobium borbori DN316(T). With other strains of the genus Rhizobium, the 16S rRNA gene sequence similarity was less than 96.3 %. Strain JC85(T) could tolerate up to 3 % salinity, fix N(2), was resistant to ampicillin (10 µg) and was positive for catalase and oxidase. The major fatty acid was C(18 : 1)ω7c (69 %) with minor amounts of C(19 : 0) cyclo ω8c (8.9 %), C(16 : 0) (6.9 %), C(12 : 0) (5.7 %) and C(19 : 1)ω7c/C(19 : 1)ω6c (2.2 %). Polar lipids of strain JC85(T) include two unidentified aminophospholipids (APL1,2), two unidentified phospholipids (PL1,2), phosphatidylcholine and four unidentified lipids (L1-4). Q-10 is the major quinone of strain JC85(T). Based on polyphasic taxonomic analysis, strain JC85(T) represents a novel species for which, the name Rhizobium subbaraonis JC85(T) is proposed. The type strain is JC85(T) ( = DSM 24765(T) = KCTC 23614(T)).

  5. Radiological risk assessment of natural radionuclides in sand collected from some beaches along the coastline of southwestern Nigeria.

    Science.gov (United States)

    Ademola, J A; Nwafor, C O

    2013-10-01

    The activity concentrations of natural radionuclides in sand from three beaches in southwestern Nigeria had been determined employing the gamma-ray spectroscopy method. The mean activity concentrations of (226)Ra, (232)Th and (40)K, respectively, were 12.5 ± 3.3, 25.8 ± 4.7 and 153.9 ± 18.5 Bq kg(-1) for Suntan Beach, 13.1 ± 3.1, 23.9 ± 4.5 and 219.9 ± 33.9 Bq kg(-1) for Bar Beach. Lekki Beach had 13.2 ± 3.2, 26.3 ± 3.8 and 149.0 ± 19.8 Bq kg(-1), respectively. The absorbed dose rates were calculated as 27.8 ± 3.1, 29.7 ± 4.0, 28.2 ± 3.3 nGy h(-1), respectively. The corresponding annual effective doses are 0.034 ± 0.004, 0.036 ± 0.005, 0.035 ± 0.004 mSv y(-1), which are less than the limit of 1 mSv y(-1) recommended for the members of the public. The radiological hazard indices are within the maximum recommended limits, hence pose no significant radiological hazards for construction.

  6. Antimicrobial Susceptibility of Staphylococcus aureus Isolated from Recreational Waters and Beach Sand in Eastern Cape Province of South Africa.

    Science.gov (United States)

    Akanbi, Olufemi Emmanuel; Njom, Henry Akum; Fri, Justine; Otigbu, Anthony C; Clarke, Anna M

    2017-09-01

    Background: Resistance of Staphylococcus aureus to commonly used antibiotics is linked to their ability to acquire and disseminate antimicrobial-resistant determinants in nature, and the marine environment may serve as a reservoir for antibiotic-resistant bacteria. This study determined the antibiotic sensitivity profile of S.aureus isolated from selected beach water and intertidal beach sand in the Eastern Cape Province of South Africa. Methods: Two hundred and forty-nine beach sand and water samples were obtained from 10 beaches from April 2015 to April 2016. Staphylococcus aureus was isolated from the samples using standard microbiological methods and subjected to susceptibility testing to 15 antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) was detected by susceptibility to oxacillin and growth on Brilliance MRSA II agar. Antibiotic resistance genes including mecA, femA rpoB, blaZ, ermB, ermA, ermC, vanA, vanB, tetK and tetM were screened. Results: Thirty isolates (12.3%) were positive for S. aureus by PCR with over 50% showing phenotypic resistance to methicillin. Resistance of S. aureus to antibiotics varied considerably with the highest resistance recorded to ampicillin and penicillin (96.7%), rifampicin and clindamycin (80%), oxacillin (73.3%) and erythromycin (70%). S.aureus revealed varying susceptibility to imipenem (96.7%), levofloxacin (86.7%), chloramphenicol (83.3%), cefoxitin (76.7%), ciprofloxacin (66.7%), gentamycin (63.3%), tetracycline and sulfamethoxazole-trimethoprim (56.7%), and vancomycin and doxycycline (50%). All 30 (100%) S. aureus isolates showed multiple antibiotic-resistant patterns (resistant to three or more antibiotics). The mecA, femA, rpoB, blaZ, ermB and tetM genes were detected in 5 (22.7%), 16 (53.3%), 11 (45.8%), 16 (55.2%), 15 (71.4%), and 8 (72.7%) isolates respectively; Conclusions: Results from this study indicate that beach water and sand from the Eastern Cape Province of South Africa may be potential

  7. Liquefaction Resistance of Chlef River Silty Sand: Effect of Low Plastic Fines and other Parameters

    Directory of Open Access Journals (Sweden)

    Tom Schanz

    2010-07-01

    Full Text Available Silty sands are the most common type of soil that could be involved in both staticand earthquake-induced liquefaction. Most of the recent earthquakes have revealed theliquefaction of silty sands. Therefore, the selection of the appropriate undrained residualshear strength of liquefied soils to be used in the assessment of the post-liquefactionstability of earth dams and other earth structures is becoming a major challenge. A seriesof undrained monotonic and cyclic triaxial tests were carried out on reconstituted saturatedsamples of sand with variation in the fines content ranging from 0 to 50% for themonotonic tests and from 0 to 40% for the cyclic ones, in order to study the influence offines fraction and other parameters on the undrained residual shear strength andliquefaction potential of loose, medium dense and dense silty sand samples (Dr = 12%,50%, 60% and 90%. The results of the monotonic tests show that the stress-strain responseand shear strength behaviour is controlled by the percentage of fines fraction and thesamples become contractive for the studied relative densities (Dr = 12% and 90%. The undrained residual shear strength decreases as the global void ratio decreases and thefines content increases up to 30% fines content. Beyond that, it decreases with increasingthe global void ratio and the fines content. Moreover, the undrained residual strengthdecreases linearly as the fines content and the inter-granular void ratio increase. Cyclictest results show that the increase of the fines fraction accelerates the liquefactionphenomenon for the studied amplitude and the liquefaction resistance decreases with theincrease of the global void ratio and the loading amplitude. We notice that the reduction inthe liquefaction resistance of Chlef sand-silt mixtures becomes very marked for the smallercyclic stress ratios CSR = 0.15 and 0.25.

  8. Geochemical studies of monazite sands of Chhatrapur beach placer deposit of Orissa, India by PIXE and EDXRF method

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, A.K.; Das, S.K.; Vijayan, V.; Sengupta, D. E-mail: dsgg@gg.iitkgp.ernet.in; Saha, S.K

    2003-09-01

    Geochemical characteristics of monazite sands of Chhatrapur beach placer deposit were studied by proton induced X-ray emission and energy dispersive X-ray fluorescence methods. The average concentrations of ThO{sub 2} and UO{sub 2} are found to be 10.18 and 0.26 wt.%, respectively. The average rare-earth elements (REE) content is 56.75 wt.% and they are rich in La, Ce and Nd. The most characteristic feature common to all monazites is that the total REE content exceeds that of the actinides (U + Th). The chondrite-normalized REE distribution patterns of monazite grains shows uniformly enriched light rare-earth element, which could be due to the preferential incorporation of lighter lanthanides. These monazite sands are derived from the granulite facies of metamorphic rocks such as khondalites and charnockites from Eastern Ghats Group of rocks.

  9. Uptake of Organic Contaminants by Plants from Oil Sands Fine Tailings

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The objectives of this experiment were to evaluate the performance of different plant species growing in different kinds of oil sands fine tailings,and to estimate the uptake of organic contaminants by plants from the oil sands fine tailings.In general,total hydrocarbon in the plant could be ranked(beginning with the highest)as:unweathered plant 4 tailings (UWT),Freeze-Thawtailings(FT),weathered plant 4 tailings(WT),and consolidated tailings(CT) for the willow,poplar and cattails.For grass,CT amended with tailings sand and muskeg had the highest hydrocarbon level in the field treatment,however,other three kinds of tailings(FT,WT and UWT) had lower but similar to each other hydrocarbon levels.

  10. The effects of storms and storm-generated currents on sand beaches in Southern Maine, USA

    Science.gov (United States)

    Hill, H.W.; Kelley, J.T.; Belknap, D.F.; Dickson, S.M.

    2004-01-01

    Storms are one of the most important controls on the cycle of erosion and accretion on beaches. Current meters placed in shoreface locations of Saco Bay and Wells Embayment, ME, recorded bottom currents during the winter months of 2000 and 2001, while teams of volunteers profiled the topography of nearby beaches. Coupling offshore meteorological and beach profile data made it possible to determine the response of nine beaches in southern Maine to various oceanographic and meteorological conditions. The beaches selected for profiling ranged from pristine to completely developed and permitted further examination of the role of seawalls on the response of beaches to storms. Current meters documented three unique types of storms: frontal passages, southwest storms, and northeast storms. In general, the current meter results indicate that frontal passages and southwest storms were responsible for bringing sediment towards the shore, while northeast storms resulted in a net movement of sediment away from the beach. During the 1999-2000 winter, there were a greater percentage of frontal passages and southwest storms, while during the 2000-2001 winter, there were more northeast storms. The sediment that was transported landward during the 1999-2000 winter was reworked into the berm along moderately and highly developed beaches during the next summer. A northeast storm on March 5-6, 2001, resulted in currents in excess of 1 m s-1 and wave heights that reached six meters. The storm persisted over 10 high tides and caused coastal flooding and property damage. Topographic profiles made before and after the storm demonstrate that developed beaches experienced a loss of sediment volume during the storm, while sediment was redistributed along the profile on moderately developed and undeveloped beaches. Two months after the storm, the profiles along the developed beaches had not reached their pre-storm elevation. In comparison, the moderately developed and undeveloped beaches

  11. A predictive model for microbial counts on beaches where intertidal sand is the primary source.

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Wang, John D; Fleming, Lora E

    2015-05-15

    Human health protection at recreational beaches requires accurate and timely information on microbiological conditions to issue advisories. The objective of this study was to develop a new numerical mass balance model for enterococci levels on nonpoint source beaches. The significant advantage of this model is its easy implementation, and it provides a detailed description of the cross-shore distribution of enterococci that is useful for beach management purposes. The performance of the balance model was evaluated by comparing predicted exceedances of a beach advisory threshold value to field data, and to a traditional regression model. Both the balance model and regression equation predicted approximately 70% the advisories correctly at the knee depth and over 90% at the waist depth. The balance model has the advantage over the regression equation in its ability to simulate spatiotemporal variations of microbial levels, and it is recommended for making more informed management decisions.

  12. Analysis and Interpretation of the Field and Laboratory Geophysical Measurements of Black-Sand Beach Deposits, East Rosetta, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed A. El-Sadek

    2012-01-01

    Full Text Available The present study deals with the analysis and interpretation of the results of field geophysical survey and laboratory geophysical measurements. The study of the magnetic and electrical methods was selected because the beach sands contain many minerals that have magnetic and electric properties. Analysis and interpretation of the field and laboratory magnetic and geoelectric maps demonstrated that the investigated beach-alluvial deposits can be subdivided according to their magnetic and geoelectric properties into three main zones striking nearly parallel to the shoreline of the Mediterranean Sea at the study area. The northern zone is more enriched in black sands than the central or southern zones. Field and laboratory magnetic susceptibility measurements provided very useful maps for the concentration of heavy minerals. The deep-seated magnetic response was calculated at an average depth of 239.6 m, while the near-surface magnetic responses were computed at average depths of 9.1, 57.9, and 81.8 m, respectively. The correlation between the geophysical features, recorded on the total magnetic field intensity, the electric resistivity, the IP chargeability, and the calculated metal factor, was found to agree to a great extent. The heavymineral concentration was found to decrease with depth. However, the heavyminerals show parallel zones below the surface, suggesting similar sedimentation environments.

  13. Meiofauna of some sandy beaches of Andaman Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Ingole, B.S.

    Comparatively high meiofauna numbers were recorded from beaches having fine sand particles than those having coarse to medium sand particles The fauna was dominated mainly by nematodes (53.7%), harpacticoids (13.7%) and polychaetes (12.8%) On all...

  14. Geochemistry and U-Pb geochronology of detrital zircons in the Brujas beach sands, Campeche, Southwestern Gulf of Mexico, Mexico

    Science.gov (United States)

    Tapia-Fernandez, Hector J.; Armstrong-Altrin, John S.; Selvaraj, Kandasamy

    2017-07-01

    This study investigated the bulk sediment geochemistry, U-Pb ages and rare earth element (REE) geochemistry of one hundred detrital zircons recovered from the Brujas beach sands in southwestern Gulf of Mexico to understand the provenance and age spectra. The bulk sediments are high in Zr and Hf contents (∼1400-3773 ppm and ∼33-90 ppm, respectively) suggested the abundance of resistant mineral zircon. The chondrite normalized REE patterns of the bulk sediments are less fractionated with enriched low REE (LREE; LaCN/SmCN = ∼491-693), depleted heavy REE (HREE; GdCN/YbCN = ∼44-69) and a negative Eu anomaly (Eu/Eu∗ = ∼0.44-0.67) suggested that the source rock is felsic type. The results of this study revealed highly varied contents of Th (∼4.2-321 ppm), U (∼20.7-1680 ppm), and Hf (∼6970-14,200 ppm) in detrital zircons compared to bulk sands. The total REE content (∼75 and 1600 ppm) and its chondrite-normalized pattern with positive Ce and negative Eu anomalies as well as low Th/U ratio of zircon grains indicated that they were dominantly of magmatic origin. U-Pb data of zircons indicated two age populations, with predominance of Permian-Triassic (∼216-286 Ma) and Neoproterozoic (∼551-996 Ma). The Permian-Triassic zircons were contributed by the granitoids and recycled metasedimentary rocks of the Chiapas Massif Complex. The major contribution of Neoproterozoic zircons was from the Chaucus, Oaxacan, and Chiapas Massif Complexes in Grenville Province, southern Mexico. U-Pb ages of zircons from the Brujas beach are consistent to the reported zircon ages from the drainage basins of Usumacinta, Coatzacoalcos, and Grijalva Rivers in southern Mexico, suggesting that the sediments delivered by the rivers to the beach area are vital in defining the provenance of placers.

  15. Assessment of gamma radiation exposure and distribution of natural radioactivity in beach sands associated with plutonic rocks of Greece

    Science.gov (United States)

    Papadopoulos, Argyrios; Koroneos, Antonios; Christofides, Georgios; Stoulos, Stylianos

    2016-04-01

    This study aims to evaluate the activity concentrations of 238U, 226Ra, 232Th, 228Th and 40K along beaches of Greece associated with plutonic rocks. They range from 6-940, 1-2292, 5-10143, 5-9953 and 27-1319 Bq/kg respectively, with some of them representing the highest values of natural radioactivity measured in sediments in Greece. The investigated beaches include Sithonia peninsula (Chalkidiki, N. Greece), some islands of the Aegean Sea (Mykonos, Paros, Naxos, Serifos, Ikaria), the area of Kavala (N. Greece), Samothraki island, NE Chalkidiki and Maronia (NE Greece). Several of these places are associated with high touristic activity such as Mykonos, Naxos, Paros, Serifos, Ikaria, Sithonia and Kavala. The (% wt.) heavy magnetic fraction (HM) (allanite, amphibole, mica, clinopyroxene, magnetite and hematite), the heavy non-magnetic fraction (HNM) (monazite, zircon, titanite and apatite) and the total heavy fraction (TH), were correlated with the concentrations of the measured radionuclides in the bulk samples. The heavy fractions seem to control the activity concentrations of 238U and 232Th of all the samples, showing some local differences in the main 238U and 232Th mineral carrier. The measured radionuclides in the beach sands were normalized to the respective values measured in the granitic rocks, which are their most probable parental rocks, so as to provide data upon their enrichment or depletion. The highest values of the equivalent dose have been reported in Mykonos, Naxos, Kavala and Sithonia. The annual equivalent dose which should be limited to at least 1 mSv y-1, varies between 0.003 and 0.759 mSv y-1 for tourists and from 0.012 to 3.164 mSv y-1 for local people working on the beach.

  16. Programs to obtain vertical heights from mean sea level and for computing volume of sand/mineral along beaches: A case study with Kalbadevi beach profiling data and results

    Digital Repository Service at National Institute of Oceanography (India)

    Ganesan, P.

    Two programs have been developed to process profile data, for obtaining vertical heights with respect to mean sea level (M.S.L.) and for computation of volume of heavy mineral / sand accumulation or erosion along the beaches. The final output...

  17. Requerimientos y disponibilidad de arenas parala defensa de las playas de Necochea y Lobería Requirements and availability of sand for theprotection of Nechochea and Lobería beaches

    Directory of Open Access Journals (Sweden)

    Federico Isla

    2009-11-01

    Full Text Available La costa de Lobería y Necochea se caracteriza poracantilados y playas de escaso desarrollo. La desembocadura del río QuequénGrande alteraba la línea de costa. La construcción de las escolleras del puertode Quequén indujo una gran acumulación de arena en el sector de Necochea, y uncrítico proceso erosivo de los acantilados y en las playas del este. El anchode las playas se reduce de 300 m en el oeste a sólo 40-60 m hacia el este.Considerando la escasez generalizada de arena, las playas del este son las quetienen mayor variabilidad sedimentaria. Las mayores variaciones en los balancesde arena fueron originadas por actividades humanas. Las olas provenientes delE, SE y S proyectan mayor energía en este sector oriental. Por otro lado, lossectores infralitorales de estas playas tienen poca disponibilidad de arena. Lamayor abundancia de arena fina ha sido reconocida hacia el balneario Necochea.El río Quequén Grande tiene un significativo efecto sobre la dinámica delestuario durante las crecidas originadas por eventos ENSO, aunque la sedimentaciónestá dominada por aportes de limo.Thecoast of Lobería and Necochea is characterized by cliffsand narrow beaches. Theinlet of the Quequén Grande river used to alter the coastline. The constructionof jetties related to the Quequén Harbour induced huge accumulations of sandtowards Necochea, and a critic erosive process of cliff and beach to the east.Beach width reduces from 300 m at the west to 40-60 m to the east. Consideringregional sand scarcity, the eastern beaches are characterized by more sandvariability. Greater variations in the sand balance were assigned to humanactivity. Waves coming from the E, SE and S deliver more energy along thiseastern sector. On the other hand, submerged zones of these beaches have lessavailability of sand. Greater availability of fine sand was recognized towardsNecochea. The Quequén Grande river has much effect on the estuarine dynamicsduring ENSO

  18. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand

    NARCIS (Netherlands)

    Nolet, Corjan; Poortinga, Ate; Roosjen, Peter; Bartholomeus, Harm; Ruessink, Gerben

    2014-01-01

    Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure

  19. Number of bacteria decomposing organic phosphorus compounds and phosphatase activity in the sand of two marine beaches differing in the level of anthropopressure.

    Science.gov (United States)

    Mudryk, Z J; Perliński, P; Antonowicz, J; Robak, D

    2015-12-30

    Number of heterotrophic bacteria ability to decompose organic phosphorus compounds and the level of phosphatase activity in the sand of two marine beaches (southern coast of the Baltic Sea) differing in the level of anthropopressure were studied. The study showed that the number of bacteria and level phosphatase activity were higher in the sand of the beach subjected to stronger anthropopressure. In both studied beaches bacteria hydrolysing DNA were the most numerous (92.7-302.8 CFU·g(-1) d.w.). The least numerous were phytin (26.0·10(3) CFU·g(-1) d.w.) and phenolphthalein diphosphate (11.1·10(3) CFU·g(-1) d.w.) decomposing bacteria. Number of bacteria able to attack tested organic phosphorus compounds were the most numerous in dry zones (10.77-739.92 CFU·g(-1) d.w.) then wet zones (3.34-218.15 CFU·g(-1) d.w.). In both studied beaches bacteria hydrolysing organic phosphorus compounds and phosphatase activity generally were more numerous in surface sand layer. Seasonal variation in the occurrence of bacteria in both studied beaches was observed.

  20. Texture, carbonate content and component composition of Mauritius beach sands, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Veerayya, M.; Guptha, M.V.S.

    of foraminiferal tests which vary from 45 to 91.6%. The discoloured foraminiferal tests in the backshore region of Points aux Sables beach on the western shore and at Souillac and Baie du Cap along the southern shore reflect a relict source (Holocene age...

  1. Pore water chemistry in the beach sands of central Tamil Nadu, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandrasekar, N.; Gujar, A.R.; Loveson, V.J.; Rajamanickam, G.V.; Moscow, S.; Manickaraj, D.S.; Chandrasekaran, R.; Chaturvedi, S.K.; Mahesh, R.; Sudha, V.; Josephine, P.J.; Deepa, V.

    As the pore water chemistry- has been considered as one of the prominent base parameters to infer the impact of coastal mining in introducing environmental deterioration, a study in pore water chemistry is planned here along the beaches for a length...

  2. Basic Properties of Concrete Incorporating Recycled Ceramic Aggregate and Ultra-fine Sand

    Institute of Scientific and Technical Information of China (English)

    LIU Fengli; LIU Junhua; MA Baoguo; HUANG Jian; LI Hainan

    2015-01-01

    Recycled ceramic mixed sand (RCMS) was obtained by partially replacing ultra-fine sand with recycled ceramic coarse sand (RCCS). The effects of RCCS replacement rate on the apparent density, workability, compressive strength and splitting tensile strength of recycled ceramic concrete (RCC) were investigated. In addition, the relationship between the water-cement ratio and compressive strength of RCC was also studied. The experimental results indicate that the reusing of recycled ceramic aggregate can improve the cohesiveness and water retentiveness of fresh concrete and benefit the mechanical properties development. When the RCCS replacement rate is not less than 40%, the mechanical properties of RCC are superior to those of the reference concrete. Moreover, when recycled ceramic medium sand was completely used as fine aggregate, the maximum increase in both compressive strength and splitting tensile strength were obtained, comparing with those of reference concrete, the increment ratio was 19.85% and 32.73%, respectively. The microscopic analysis shows that the using of recycled ceramic aggregate can meliorate distinctly the structure of the interfacial transition zone (ITZ) and increase the compaction degree of cement paste. Furthermore, an expression of the compressive strength of RCC and the cement-water ratio is regressed and gains a good linear relativity. It is an effective way to recycle waste ceramic, and the consumption of recycled ceramic aggregate could reach from 26.9%to 47.6%of the total weight of aggregate in producing concrete.

  3. Undrained dynamical behavior of Nanjing flake-shaped fine sand under cyclic loading

    Institute of Scientific and Technical Information of China (English)

    陈国兴; 刘雪珠; 战吉艳

    2008-01-01

    A series of dynamic behavior tests on Nanjing flake-shaped fine sand were performed by using the WFI cyclic triaxial apparatus made in England. The dynamic behaviors of Nanjing flake-shaped fine sand under different static deviator stress levels and cyclic stress ratios were studied. Through comparing the effective stress path under cyclic loading with static loading, the processes of liquefaction of saturated Nanjing flake-shaped fine sand with development of dynamic pore-water pressure, including the initial compact state, compression state and dilative state, were investigated. The variation of the shear stiffness with the number of cycles and cyclic strain was investigated by analyzing the secant shear modulus in each unload-reload loop of dynamic stress-strain relationship. And by means of the exponential function, the empirical equations of the relationship between secant shear modulus Gsec, shear modulus ratio Gsec/Gmax and cyclic strain ε were established based on series of test results. The results show that according to different combinations of static deviator stress and cyclic stress, two kinds of failure patterns with deviator stress reversal or no deviator stress reversal are observed in the samples tested in this series, including cyclic mobility and the failure of accumulation residual strain. In addition, the degradation of dynamic shear modulus is due to the development of vibration pore-water pressure and it is observed that the shear modulus reduces with the progressive number of cycles.

  4. Migration and transformation characteristics of DOM in fine sand and marl rock.

    Science.gov (United States)

    Wang, Xinyi; Zhen, Xiaoge; Li, Renzheng; Liu, Xiaoman; Wang, Tiantian; Zhao, Li; Yang, Jian

    2016-01-01

    This paper mainly studied migration and transformation characteristics of dissolved organic matter (DOM) in underground aquifers. To achieve the research purpose, we carried out the dynamic column experiments of the DOM at different conditions indoors. In the experiment, the water of Wujiang River from Pingdingshan Coal-field is used as water sample, meanwhile, fine sand and marl rock are used as testing rock sample. A comparative study on migration and transformation characteristics of the DOM in different rock samples is done. The results show that, in the fine sand, the main effects are convection and dispersion, while the adsorption and biological effects are very weak. However, in the marl rock, besides existing convection and dispersion, the adsorption and biological effect are quite significant. And in the marl rock, convection and dispersion plays a major role in the early experiment, while adsorption is the main effect in the medium term, then the biodegradation dominates the final stage. With the increasing of temperature and seepage velocity in the fine sand, the impact of the convection effect becomes gradually weak, the dispersion effect gradually enhances, and, however, convection effect is still playing a dominant role. With the temperature rising in the marl rock, the adsorption effect becomes weak, but biodegradation is enhanced. As the seepage velocity increases in the marl rock, the adsorption and biodegradation both decrease.

  5. Synthesis and characterization of mullite–zirconia composites by reaction sintering of zircon flour and sillimanite beach sand

    Indian Academy of Sciences (India)

    P Kumar; M Nath; A Ghosh; H S Tripathi

    2015-10-01

    Mullite–zirconia composites containing 10–30 wt% zirconia were prepared by reaction sintering of zircon flour, sillimanite beach sand and calcined alumina. Raw materials were attrition milled, shaped into pellets and bars and sintered in the temperature range of 1450–1600°C with 2 h soaking at peak temperature. Sintered products were analysed in terms of various physical, mechanical and thermo-mechanical properties. The analyses of phases developed and microstructural analyses were carried out by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. It was observed that the addition of ZrO2 up to 20 wt% significantly improves flexural strength and fracture toughness. The transformation of t $\\rightarrow$ m zirconia was found to be the dominant mechanism for enhancement in mechanical properties. ZrO2 occupies both the intergranular as well as intragranular positions. However, intragranular zirconias are much smaller compared to intergranular zirconias.

  6. Scalable synthesis of nano-silicon from beach sand for long cycle life Li-ion batteries.

    Science.gov (United States)

    Favors, Zachary; Wang, Wei; Bay, Hamed Hosseini; Mutlu, Zafer; Ahmed, Kazi; Liu, Chueh; Ozkan, Mihrimah; Ozkan, Cengiz S

    2014-07-08

    Herein, porous nano-silicon has been synthesized via a highly scalable heat scavenger-assisted magnesiothermic reduction of beach sand. This environmentally benign, highly abundant, and low cost SiO₂ source allows for production of nano-silicon at the industry level with excellent electrochemical performance as an anode material for Li-ion batteries. The addition of NaCl, as an effective heat scavenger for the highly exothermic magnesium reduction process, promotes the formation of an interconnected 3D network of nano-silicon with a thickness of 8-10 nm. Carbon coated nano-silicon electrodes achieve remarkable electrochemical performance with a capacity of 1024 mAhg(-1) at 2 Ag(-1) after 1000 cycles.

  7. Hydrocarbon-Degrading Bacteria and the Bacterial Community Response in Gulf of Mexico Beach Sands Impacted by the Deepwater Horizon Oil Spill▿†‡

    Science.gov (United States)

    Kostka, Joel E.; Prakash, Om; Overholt, Will A.; Green, Stefan J.; Freyer, Gina; Canion, Andy; Delgardio, Jonathan; Norton, Nikita; Hazen, Terry C.; Huettel, Markus

    2011-01-01

    A significant portion of oil from the recent Deepwater Horizon (DH) oil spill in the Gulf of Mexico was transported to the shoreline, where it may have severe ecological and economic consequences. The objectives of this study were (i) to identify and characterize predominant oil-degrading taxa that may be used as model hydrocarbon degraders or as microbial indicators of contamination and (ii) to characterize the in situ response of indigenous bacterial communities to oil contamination in beach ecosystems. This study was conducted at municipal Pensacola Beach, FL, where chemical analysis revealed weathered oil petroleum hydrocarbon (C8 to C40) concentrations ranging from 3.1 to 4,500 mg kg−1 in beach sands. A total of 24 bacterial strains from 14 genera were isolated from oiled beach sands and confirmed as oil-degrading microorganisms. Isolated bacterial strains were primarily Gammaproteobacteria, including representatives of genera with known oil degraders (Alcanivorax, Marinobacter, Pseudomonas, and Acinetobacter). Sequence libraries generated from oiled sands revealed phylotypes that showed high sequence identity (up to 99%) to rRNA gene sequences from the oil-degrading bacterial isolates. The abundance of bacterial SSU rRNA gene sequences was ∼10-fold higher in oiled (0.44 × 107 to 10.2 × 107 copies g−1) versus clean (0.024 × 107 to 1.4 × 107 copies g−1) sand. Community analysis revealed a distinct response to oil contamination, and SSU rRNA gene abundance derived from the genus Alcanivorax showed the largest increase in relative abundance in contaminated samples. We conclude that oil contamination from the DH spill had a profound impact on the abundance and community composition of indigenous bacteria in Gulf beach sands, and our evidence points to members of the Gammaproteobacteria (Alcanivorax, Marinobacter) and Alphaproteobacteria (Rhodobacteraceae) as key players in oil degradation there. PMID:21948834

  8. {sup 226}Ra, {sup 232}Th and {sup 40}K analysis in sand samples from some beaches of Great Vitoria, Espirito Santo, Brazil: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Reginaldo R.; Pecequilo, Brigitte R.S., E-mail: raquino@ipen.b, E-mail: brigitte@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2009-07-01

    The natural radioactivity in superficial beach sand samples of 7 beaches of Great Vitoria, metropolitan region of the State of Espirito Santo, southeast Brazil, was determined from the {sup 226}Ra, {sup 232}Th and {sup 4}0{sup K} contents. The assessed beaches were Manguinhos, Camburi, Praia do Canto, Curva da Jurema, Itapua, Setibao and Areia Preta. Three samples of each beach were sealed in standard 100 mL polyethylene flasks and stored in order to obtain secular equilibrium in the {sup 238}U and {sup 232}Th series. All samples were measured by high resolution gamma spectrometry and the spectra were analyzed with the WinnerGamma software. The {sup 232}Th concentration was determined from the average concentrations of {sup 228}Ac, {sup 212}Pb and {sup 212}Bi and the {sup 226}Ra concentration was determined from the average concentrations of {sup 214}Pb and {sup 214}Bi. Preliminary results show concentrations varying from 9 Bq.kg{sup -1} to 6035 Bq.kg{sup -1} for {sup 232}Th, from 4 Bq.kg{sup -1} to 575 Bq.kg{sup -1} for {sup 226}Ra and from 13 Bq.kg{sup -1} to 142 Bq.kg{sup -1} for {sup 40}K. Areia Preta beach shows the highest values for {sup 232}Th, while the highest value for {sup 226}Ra was observed for Camburi beach. High values of {sup 40}K were observed for Curva da Jurema beach. (author)

  9. Petrography and geochemistry of sands from the Chachalacas and Veracruz beach areas, western Gulf of Mexico, Mexico: Constraints on provenance and tectonic setting

    Science.gov (United States)

    Armstrong-Altrin, John S.; Nagarajan, Ramasamy; Balaram, Vysetti; Natalhy-Pineda, Olmedo

    2015-12-01

    Compositional and geochemical analyses of sands collected from the Chachalacas (CHA) and Veracruz (VER) beach areas along the western Gulf of Mexico were studied to determine the provenance and tectonic setting of the source region. The modal composition showed that the proportion of quartz (Q) is lower in CHA than in VER sands. The average quartz-feldspar-lithic fragment (QFL) ratios for the CHA and VER sands are Q75F8L17 and Q86F4L10, respectively. The X-ray diffractometer (XRD) and Scanning Electron Microscope equipped with EDAX spectrometer (SEM-EDS) data revealed that the CHA sands were abundant in heavy minerals like magnetite, ilmenite, and zircon. The rare earth element concentration (REE) is higher in CHA than in VER sands, which is due to the concentration of heavy minerals in CHA sands. The weathering indices such as chemical index of alteration (CIA), plagioclase index of alteration, and A-CN-K (A = Al2O3, CN = CaO∗ + Na2O, K = K2O) plot suggested that the intensity of weathering in the source area was low to moderate. The index of chemical variability (ICV) for the CHA (˜1.9-3.0) and VER (˜0.82-1.33) sands indicated that the compositional maturity was higher for the VER sands. The concentrations of Co, Cr, Ni, and V are lower in VER sands than in CHA sands, indicating that the CHA sands were derived from the intermediate source rocks. Provenance modelling revealed that the CHA sands were associated with the mixture of basalt, andesite, dacite, and trachyandesite in the ratio of 5:20:25:50. The VER sands were best matched with a mixture having 75-90% dacite and 25-10% andesite compositions. The provenance difference between the two beach areas suggested that longshore current play a less significant role in mixing and homogenization of sands. The multidimensional tectonic discrimination diagrams revealed rift and collision settings for the VER and CHA beach areas, respectively, which is consistent with the general geology of the study areas.

  10. Biogeochemical Controls on Biodegradation of MC252 Oil:Sand Aggregates on a Rapidly Eroding Coastal Headland Beach

    Science.gov (United States)

    Pardue, J.; Elango, V.; Urbano, M.; Lemelle, K.

    2012-12-01

    The research described below was conducted on Fourchon Beach, a coastal headland consisting of nine miles of fairly pristine sandy beaches and dunes, backed by wetlands and tidal channels, located between Belle Pass tidal inlet on the west and Elmer's Island on the east in Lafourche Parish, Louisiana. MC252 oil first arrived in large quantities on Fourchon Beach on or around May 20, 2010. A unique oil form created under these conditions was an aggregate of sand and emulsified oil, typically 0.1-10 cm in diameter, termed small surface residue balls (SSRBs). The work from this project made critical measurements on the factors controlling biodegradability of these SSRB aggregates. SSRB aggregates were sampled across transects perpendicular to the beach from the intertidal to the supratidal. Areas in the supratidal that were sampled initially were set aside for research purposes and not altered by any clean-up activities. Chemical composition of SSRBs was measured including concentrations of n-alkanes, PAHs, hopanes, nutrients (nitrate, nitrite, ammonium and orthophosphate measured on water extracts of SSRBs), and electron acceptor concentrations (O2 microprofiles measured on intact SSRBs and sulfate). Physical characterization of the SSRBs including length and area dimensions, mass, density, porosity, moisture content, and salinity using standard methods. Microbial characterization of SSRBs was also conducted using denaturing gradient gel electrophoresis and sequencing of dominant bands. SSRBs were sampled from various locations across the beach profile deposited by 2 significant tropical events in 2010; Hurricane Alex and TS Bonnie, and one event in 2011, TS Lee. Sampling focused on comparing and contrasting impacts of biogeochemistry on weathering of oil stranded in three beach microenvironments; supratidal surface; subtidal subsurface which is permanently inundated and intertidal subsurface samples which are intermittently inundated. The three types of oil are

  11. Natural and anthropogenic radionuclides in rocks and beach sands from Ezine region (Canakkale), Western Anatolia, Turkey.

    Science.gov (United States)

    Orgün, Y; Altinsoy, N; Sahin, S Y; Güngör, Y; Gültekin, A H; Karahan, G; Karacik, Z

    2007-06-01

    This paper represents the first reports on the natural and anthropogenic radionuclides in Kestanbol granitic pluton and surrounding rocks, and coastal region of the Ezine town. To assess the radiological hazard of the natural radioactivity, the radium equivalent activity, the absorbed dose rate and the external hazard index were calculated, and in situ gamma dose rates were measured. The high-activity concentrations were measured in the pluton and sands, which was originated mainly from the pluton, due to the presence of zircon, allanite, monazite, thorite, uranothorite and apatite. The average activity concentrations of (238)U, (232)Th and (40)K are 174.78, 204.69 and 1171.95 Bq kg(-1) for pluton, and 290.36, 532.04 and 1160.75 Bq kg(-1) for sands, respectively. (137)Cs in Ezine region ranged from 0-6.57 Bq kg(-1). The average absorbed dose rate for the granitic and sand samples were calculated to be 251.6 and 527.92 nGy h(-1), respectively. The maximum contribution to the total absorbed gamma dose rate in air was due to the (232)Th (52.3% for pluton and 67.1% for sands). The Raeq activities of the pluton and sands are higher than the recommended maximum value of 370 Bq kg(-1) criterion limit of Raeq activity for building materials.

  12. Comparison of polymer applications to treatment of oil sands fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Zhou, J.; Chow, R. [Alberta Research Council, Edmonton, AB (Canada)

    2008-07-01

    Oil sands tailings are disposed of into large ponds where the coarse particles settle out, and fine particles settle down very slowly to form a stable suspension called mature fine tailings (MFTs). Many oil sands projects are not meeting tailings management targets. Polymer applications are being designed to create agglomerated particles. This presentation discussed a study that compared 3 types of polymers in solids dewatering processes: (1) polyacrylamide (PAM); a aluminum PAM hybrid (Al-PAM) and a thermal-sensitive poly(N-isopropyl acrylamide (PNIPAM). The aim of the study was to determine the optimal polymeric facilitation. Oil sands tailings from lab flotation tests were used. The effect on the initial settling rate of the tailings using the polymers was studied. Inter-particle forces were also compared, as well as the effects of temperature on polymer transitions in aqueous solutions. The effects of the polymers on silica settling and consolidation were examined. Dewatering performance was also compared. Multi-function polymers (MFP) were used to enhance water recovery from settling, consolidation and filtration. Synergetic-effect polymers (SEP) were used to enhance bitumen and water recovery. Results of the study showed that PAM effectively induced solids flocculation, but flocculants were irregular in shape. Al-PAM induced stronger flocculation of particles with dense spherical flocculants. PNIPAM enhanced dewatering in both settling and consolidation. It was concluded that PNIPAM manipulated inter-particle forces with the help of external stimuli conditions to obtain solids sediment with less volume. tabs., figs.

  13. Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

    Science.gov (United States)

    Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

  14. Performance of CHROMagar Staph aureus and CHROMagar MRSA for detection of Staphylococcus aureus in seawater and beach sand--comparison of culture, agglutination, and molecular analyses.

    Science.gov (United States)

    Goodwin, K D; Pobuda, M

    2009-11-01

    Beach seawater and sand were analyzed for Staphylococcus aureus and methicillin resistant S. aureus (MRSA) for samples collected from Avalon, and Doheny Beach, CA. Membrane filtration followed by incubation on CHROMagar Staph aureus (SCA) and CHROMagar MRSA (C-MRSA) was used to enumerate S. aureus and MRSA, respectively. Media performance was evaluated by comparing identification via colony morphology and latex agglutination tests to PCR (clfA, 16S, and mecA genes). Due to background color and crowding, picking colonies from membrane filters and streaking for isolation were sometimes necessary. The specificity of SCA and C-MRSA was improved if colony isolates were identified by the presence of a matte halo in addition to mauve color; however routine agglutination testing of isolates did not appear warranted. Using the appearance of a colony on the membrane filter in conjunction with isolate appearance, the positive % agreement, the negative % agreement, and the % positive predictive accuracy for SCA was 84%, 95%, and 99% respectively, and for C-MRSA it was 85%, 98%, and 92%, respectively. Sensitivity and specificity of SCA and C-MRSA with membrane-filtered beach samples were optimized through identification experience, control of filter volume and incubation time, and isolation of colonies needing further identification. With optimization, SCA and C-MRSA could be used for enumeration of S. aureus and MRSA from samples of beach water and sand. For the sites studied here, the frequency of detection of S. aureus ranged from 60 to 76% and 53 to 79% for samples of beach seawater and sand, respectively. The frequency of detection of MRSA ranged from 2 to 9% and 0 to 12% for samples of seawater and sand, respectively.

  15. The Research Progress of Extra Fine Sand Concrete%特细砂混凝土的研究进展

    Institute of Scientific and Technical Information of China (English)

    张贺

    2016-01-01

    砂是混凝土的重要组成成分。目前我国中砂和粗砂的产量已经逐渐不能满足建筑需求,而特细砂给建筑行业带来了新的曙光,亟需将特细砂资源的潜在价值挖掘出来。对国内外特细砂混凝土的研究情况进行系统论述,并展望特细砂混凝土的发展前景,以期为新的建筑材料的开发提供参考。%Sand is the important composition of concrete. Now the production of medium sand and coarse sand have been gradually can-not meet the construction need in our country, however extra fine sand has brought a new dawn to the construction industry, therefore it is urgent to tap the potential value of extra fine sand resources. In this paper, it systematically discussed the study status about extra fine sand in China and aboard, and described the development prospect of extra fine sand so as to provide reference for the development of new building materials.

  16. Provenance, transport and composition of Dendê Coast beach sands in Bahia, central coast of Brazil

    Directory of Open Access Journals (Sweden)

    Renata Cardia Rebouças

    2011-12-01

    Full Text Available The great physiographic diversity of the Dendê Coast favors the production of different beach sediment types, including bioclastic components. In this study 74 beach samples collected at 2 km intervals were used to evaluate beach sediment composition. For each sample, 300 grains were identified for each grain size class coarser than 0.125 mm, using a binocular microscope. The beach sediments of the Dendê Coast are essentially siliciclastic (80-100%. Quartz is the major component (70-100%. Only at the Tinharé and Boipeba islands bioclasts are major components of beach sands reaching up to 80-100%. These sediments are made up essentially of fragments of Halimeda, reaching percentages up to 70%. Coralline algae and mollusks also contribute significantly to these sediments (up to 30%. The results obtained show that the spatial distribution of the bioclastic components provide important information on the environmental conditions present at the shoreline (energy levels, availability of hard substrates and protected areas, pattern of sediment dispersion and on the sediment sources as well. The composition of the beach sediments on the Dendê Coast reflects the present day environmental conditions and show that these sediments do not experience significant lateral transport. This situation is favored by an impeded longshore transport that characterizes most of the region. Although, in general, the rivers that discharge on the Dendê Coast appear to transport few sediments to the coastal zone, the presence of heavy minerals, micas and feldspars suggests river contributions to the beach sediments. On the other hand, the coral and coralline algae reefs, besides offering a natural protection to the shoreline, also represent an important source of beach sands.A grande diversidade fisiográfica da Costa do Dendê favorece a deposição de diferentes tipos de sedimentos em suas praias, inclusive sedimentos ricos em carbonato de cálcio. Neste estudo 86

  17. SOURCE PROFILES AND FINGERPRINTS OF FINE AND COARSE SANDS RESUSPENDED FROM SOILS SAMPLED IN CENTRAL INNER MONGOLIA

    Institute of Scientific and Technical Information of China (English)

    Chung-Shin Yuan; Chun-Xing Hai; Ming Zhao

    2006-01-01

    Fingerprints and source profiles of fine and coarse sands that originate from Central Inner Mongolia during Asian continental sandstorms (ACS) can be used to identify the origin of Asian sands and to trace them as they travel downwind. Soil samples collected at various land surfaces in Central Inner Mongolia were resuspended using a dry powder atomizer in an enclosure chamber. The resuspended sands were then sampled by two dichotomous samplers situated at the bottom of the enclosure chamber for fine (PM2.5) and coarse (PM2.5-10) sands, respectively. The chemical composition of sands, including water-soluble ionic species, metallic contents, and carbonaceous contents, were further analyzed. Results from resuspension tests indicated that the soils contained considerably more coarse particles than fine.Moreover, Mg, K, Al, and Fe in coarse sand had strong correlations with each other. The ratio of Mg, K, Fe (or Al) to Al (or Fe) and OC/EC in the coarse sands can be used as the fingerprints of Asian sands originating from Central Inner Mongolia.

  18. An Investigation into the Use of Manufactured Sand as a 100% Replacement for Fine Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    Martins Pilegis

    2016-06-01

    Full Text Available Manufactured sand differs from natural sea and river dredged sand in its physical and mineralogical properties. These can be both beneficial and detrimental to the fresh and hardened properties of concrete. This paper presents the results of a laboratory study in which manufactured sand produced in an industry sized crushing plant was characterised with respect to its physical and mineralogical properties. The influence of these characteristics on concrete workability and strength, when manufactured sand completely replaced natural sand in concrete, was investigated and modelled using artificial neural networks (ANN. The results show that the manufactured sand concrete made in this study generally requires a higher water/cement (w/c ratio for workability equal to that of natural sand concrete due to the higher angularity of the manufactured sand particles. Water reducing admixtures can be used to compensate for this if the manufactured sand does not contain clay particles. At the same w/c ratio, the compressive and flexural strength of manufactured sand concrete exceeds that of natural sand concrete. ANN proved a valuable and reliable method of predicting concrete strength and workability based on the properties of the fine aggregate (FA and the concrete mix composition.

  19. 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.

  20. Experimental research on accelerated consolidation using filter jackets in fine oil sands tailings

    Energy Technology Data Exchange (ETDEWEB)

    Tol van, F.; Yao, Y.; Paaseen van, L.; Everts, B. [Delft Univ. of Technology, Delft (Netherlands). Dept. of Geotechnology

    2010-07-01

    This PowerPoint presentation discussed prefabricated vertical drains used to enhance the dewatering of fine oil sand tailings. Filtration tests conducted with thickened tailings on standard PVD jackets were presented. Potential clogging mechanisms included clogging of the filter jacket by particles, blinding of the jackets by filter cake, the decreased permeability of consolidated tailings around the drain, and the clogging of the filter jacket with bitumen. Polypropylene and polyester geotextiles were tested in a set-up that replicated conditions observed at 5 to 10 meters below mud level in an oil sand tailings pond. A finite strain consolidation model was used to interpret results obtained in the experimental study. The relationship between the void ratio and hydraulic conductivity was investigated. Results of the study showed that neither the bitumen nor the fines in the sludge cause serious blinding of the filter jackets during the 40 day test period. The consolidation process was adequately simulated with the finite strain consolidation model. tabs., figs.

  1. Development of accelerated dewatering technology for managing oil sands fine fluid tailings

    Energy Technology Data Exchange (ETDEWEB)

    Lahaie, R. [Syncrude Canada Ltd., Fort McMurray, AB (Canada); Seto, J.T.C. [BGC Engineering Inc., Edmonton, AB (Canada); Chapman, D. [O' Kane Consultants Inc., Saskatoon, SK (Canada); Carrier, W.D. III [Argila Enterprises Inc., Lakeland, FL (United States)

    2010-07-01

    This article discussed an accelerated dewatering technique being applied and tested for managing fine fluid tailings produced from oil sands mining. The process involved rim ditching and a decant system to promote the drainage of surface waters and enhance the drying and densification of mature fine tailings (MFT). To field test the procedure, a deposit containing 60,000 cubic metres of in-line flocculated MFT was constructed and instrumented to monitor consolidation and dewatering response of the MFT deposit over time. Ten months after being filled, the deposit had settled about 1.2 metres, which corresponds to a 19 percent reduction in volume relative to initial filling. The field test will continue for several more years, during which time the deposit will continue to be monitored and sampled. The Florida phosphate industry has used rim ditching for over 20 years, but the process had never before been applied to oil sand tailings. The paper discussed the particular consolidation behaviour of MFT, the rim ditch concept, the layout of the containment pit and instrumentation, the pit filling procedure, and post-filling observations. 6 refs., 12 figs.

  2. Sex, Status, and Sand: California Academy of Sciences' Teen Interns Examine Trends of the Pacific Mole Crab (Emerita analoga) at Ocean Beach, San Francisco

    Science.gov (United States)

    Chu, J. B.; Conrad-Saydah, A.; Cohen, S.; Tom, R.; Robins-Moloney, M.; Masters, D.; Mason, K.; Alfaro, F.

    2003-12-01

    Student interns from the California Academy of Sciences' Careers in Sciences program monitored the Pacific mole crab (Emerita analoga), or sand crabs, in collaboration with the Farallones Marine Sanctuary Association. These small crustaceans live in the swash zone of the sandy beach habitat. Sand crabs are important in the food web, and therefore their status can help indicate the health of the larger environment. The interns helped the Gulf of the Farallones National Marine Sanctuary by monitoring the abundance and distribution of sand crabs at Ocean Beach in San Francisco, California. Students set up transects perpendicular to the shoreline, collected 10 samples along the transect, measured the carapace length, determined the sex of each crab, and checked for the presence of eggs. Students monitored June through September, 2003. Trends examined included differences in the gender ratio, size frequency, and distribution along the beach. Students also compared their data to other student data taken from other sites in San Francisco and Marin counties during 2001-2003 from the online database at http://www.sandcrabs.org. Using comparisons, interns were able to better understand the processes and significance of studying marine species. Implementation of the project was invaluable in aiding the interns in their understanding of the natural sciences and the role of monitoring habitats in environmental health.

  3. Sediment dynamics on a steep, megatidal, mixed sand-gravel-cobble beach

    Science.gov (United States)

    Hay, A. E.; Zedel, L.; Stark, N.

    2014-08-01

    Results are presented from a pilot study of shore-face sediment dynamics on a steep, poorly sorted, coarse-grained, megatidal beach at the head of the Bay of Fundy, Nova Scotia, Canada. The experiment involved the first field deployment of a prototype wideband, pulse-coherent, bistatic acoustic Doppler profiling system. Measurements of the vertical structure of flow and turbulence above a sloping bed, as well as bed material velocity, demonstrate the capabilities of this instrument vis-à-vis studies of nearshore sediment dynamics at the field scale. The second focus of the paper is the unexpected observation that the surficial sediment median diameter, across the lower two-thirds of the intertidal zone, underwent a pronounced decrease when wave forcing was more energetic, compared to values observed during calmer conditions. The explanation for this result appears to involve the formation - in wave-dominated conditions - of metre-scale wavelength, 20 cm high ripples on the rising tide, which are then planed flat by the swash and/or the shore break on the subsequent ebb.

  4. Exploring the versatility of liquid phase exfoliation: producing 2D nanosheets from talcum powder, cat litter and beach sand

    Science.gov (United States)

    Harvey, Andrew; Boland, John B.; Godwin, Ian; Kelly, Adam G.; Szydłowska, Beata M.; Murtaza, Ghulam; Thomas, Andrew; Lewis, David J.; O'Brien, Paul; Coleman, Jonathan N.

    2017-06-01

    Liquid phase exfoliation (LPE) has proven to be a versatile technique to produce uncharged 2D nanosheets from layered crystals. However, almost all studied starting materials consist of pure powder or crystals purchased from chemical suppliers. To test the true versatility of this process, we have attempted to process three starting materials with varying degrees of purity and composition. We subjected talcum powder (principle component: the layered compound talc), Fuller’s earth cat litter (known to contain layered silicate compounds, most notably palygorskite and montmorillonite/bentonite) and beach sand (suspected to contain small amounts of layered clays) to a standard LPE procedure (sonication in a surfactant solution followed by centrifugation). In all cases, we produced dispersions containing large quantities of nanosheets with almost all non-nanosheet material removed by the centrifugation step. Powder x-ray diffraction identified the nanosheets produced to be talc, a bentonite/palygorskite mixture and mica for the three starting materials respectively. Particularly interesting is the fact that bentonite, palygorskite and mica sheets are charged and are always accompanied by charge balancing counterions. We believe this is the first example of LPE being used to exfoliate and purify charged layered crystals.

  5. Service Learning Course in Which Undergraduates and Middle School Students Investigate Levels of Pathogen Indicating Bacteria in Beach Sand

    Science.gov (United States)

    Imamura, G.; Mika, K.; Lin, T.; Lee, C.; Lin, C.; Jay, J.

    2007-12-01

    Service-learning is a pedagogy that combines academic rigor with activities that address human and community needs. Over the past three years, we have developed a service-learning course that involves UCLA students working with 6th graders in an economically disadvantaged neighborhood to address issues of environmental science and health. This past year UCLA students conducted a research project in collaboration with a middle school class to investigate levels of pathogen-indicating organisms in beach sand near the Santa Monica pier. All students were taught necessary methods in class by the UCLA professor, and then met at the field site. Fieldwork involved collection of water and sand samples from various locations, extraction of bacteria from sand by shaking with buffer and decanting, and addition of sample to growth media that allow quantification of two organisms, Escherichia coli and enterococci. These organisms are typically used to indicate fecal contamination of water. Methods were straightforward and were accomplished by the 6th graders with only modest supervision by the UCLA students. Results showed extremely high levels of pathogen indicating organisms in the vicinity of a diverted stormdrain, indicating a continuing problem with the diversion. Levels decreased with distance away from the stormdrain, indicating migration of the organisms from the site of the diversion. UCLA students then visited the sixth grade classroom to help the sixth graders create Powerpoint posters including statement of hypotheses, graphs of the results, pictures of the entire process, and conclusions. Middle school students then visited UCLA to tour the campus and present their posters at a poster session hosted by the Center for Embedded Networked Sensing at UCLA. Desired outcomes at the 6th grade level included: 1) increased interest in science; 2) greater knowledge of and interest in attending college; and 3) enhanced knowledge of and feeling of political empowerment

  6. Vibration pore water pressure characteristics of saturated fine sand under partially drained condition

    Institute of Scientific and Technical Information of China (English)

    王炳辉; 陈国兴

    2008-01-01

    Vibration pore water pressure characteristics of saturated fine sand under partially drained condition were investigated through stress-controlled cyclic triaxial tests employed varied fine content of samples and loading frequency. In order to simulate the partially drained condition, one-way drainage for sample was implemented when cyclic loading was applied. The results show that the vibration pore water pressure’s response leads the axial stress and axial strain responses, and is lagged behind or simultaneous with axial strain-rate’s response for all samples in this research. In addition, the satisfactory linear relationship between vibration pore water pressure amplitude and axial strain-rate amplitude is also obtained. It means that the direct cause of vibration pore water pressure generation under partially drained conditions is not the axial stress or axial strain but the axial strain-rate. The lag-phase between pore water pressure and axial strain-rate increases with the increase of the fine content or the loading frequency.

  7. Effect of liming on yield and quality of peppermint and Sachalin mint in fine sand soil of Northern Finland

    OpenAIRE

    Aflatuni, Abbas; Uusitalo, Jouko; Ek, Sari; Hohtola, Anja

    2003-01-01

    Soil acidity commonly limits plant production in the fine sand soil of Northern Finland, which often has a low pH (5.5-6.5) and contains low levels of Ca and Mg. The effect of five liming (10% Mg and 19% Ca) levels, 0, 4, 8, 12, and 16 tons ha -1 , on the herb and essential oil yield and menthol and menthone content of two mint species (peppermint, Mentha x piperita, a variety of Black Mitcham and Sachalin mint, Mentha arvensis var. sacchalinensis) cultivated in fine sand soil in Northern Fin...

  8. The impact of particle shape on the angle of internal friction and the implications for sediment dynamics at a steep, mixed sand-gravel beach

    Science.gov (United States)

    Stark, N.; Hay, A. E.; Cheel, R.; Lake, C. B.

    2014-08-01

    The impact of particle shape on the angle of internal friction, and the resulting impact on beach sediment dynamics, is still poorly understood. In areas characterized by sediments of specific shape, particularly non-rounded particles, this can lead to large departures from the expected sediment dynamics. The steep slope (1 : 10) of the mixed sand-gravel beach at Advocate Harbour is stable in large-scale morphology over decades, despite a high tidal range of 10 m or more, and intense shore-break action during storms. The Advocate sand (d plate-like shape (Corey Shape Index, CSI ≈ 0.2-0.6). High angles of internal friction of this material were determined using direct shear, ranging from φ ≈ 41 to 49°, while the round to angular gravel was characterized as φ = 33°. The addition of 25% of the elliptic plate-like sand-sized material to the gravel led to an immediate increase in friction angle to φ = 38°. Furthermore, re-organization of the particles occurred during shearing, characterized by a short phase of settling and compaction, followed by a pronounced strong dilatory behavior and an accompanying strong increase of resistance to shear and, thus, shear stress. Long-term shearing (24 h) using a ring shear apparatus led to destruction of the particles without re-compaction. Finally, submerged particle mobilization was simulated using a tilted tray submerged in a water-filled tank. Despite a smooth tray surface, particle motion was not initiated until reaching tray tilt angles of 31° and more, being ≥7° steeper than for motion initiation of the gravel mixtures. In conclusion, geotechnical laboratory experiments quantified the important impact of the elliptic, plate-like shape of Advocate Beach sand on the angles of internal friction of both pure sand and sand-gravel mixtures. The resulting effect on initiation of particle motion was confirmed in tilting tray experiments. This makes it a vivid example of how particle shape can contribute to the

  9. Mature fine tailings from oil sands processing harbour diverse methanogenic communities.

    Science.gov (United States)

    Penner, Tara J; Foght, Julia M

    2010-06-01

    Processing oil sands to extract bitumen produces large volumes of a tailings slurry comprising water, silt, clays, unrecovered bitumen, and residual solvent used in the extraction process. Tailings are deposited into large settling basins, where the solids settle by gravity to become denser mature fine tailings (MFT). A substantial flux of methane, currently estimated at ~40 million L/day, is being emitted from the Mildred Lake Settling Basin. To better understand the biogenesis of this greenhouse gas, the methanogenic consortia in MFT samples from depth profiles in 2 tailings deposits (Mildred Lake Settling Basin and West In-Pit) were analyzed by constructing clone libraries of amplified archaeal and bacterial 16S rRNA genes. The archaeal sequences, whose closest matches were almost exclusively cultivated methanogens, were comparable within and between basins and were predominantly (87% of clones) affiliated with acetoclastic Methanosaeta spp. In contrast, bacterial clone libraries were unexpectedly diverse, with the majority (~55%) of sequences related to Proteobacteria, including some presumptive nitrate-, iron-, or sulfate-reducing, hydrocarbon-degrading genera (e.g., Thauera, Rhodoferax, and Desulfatibacillum). Thus, MFT harbour a diverse community of prokaryotes presumptively responsible for producing methane from substrates indigenous to the MFT. These findings contribute to our understanding of biogenic methane production and densification of MFT in oil sands tailings deposits.

  10. Fine root dynamics in lodgepole pine and white spruce stands along productivity gradients in reclaimed oil sands sites.

    Science.gov (United States)

    Jamro, Ghulam Murtaza; Chang, Scott X; Naeth, M Anne; Duan, Min; House, Jason

    2015-10-01

    Open-pit mining activities in the oil sands region of Alberta, Canada, create disturbed lands that, by law, must be reclaimed to a land capability equivalent to that existed before the disturbance. Re-establishment of forest cover will be affected by the production and turnover rate of fine roots. However, the relationship between fine root dynamics and tree growth has not been studied in reclaimed oil sands sites. Fine root properties (root length density, mean surface area, total root biomass, and rates of root production, turnover, and decomposition) were assessed from May to October 2011 and 2012 using sequential coring and ingrowth core methods in lodgepole pine (Pinus contorta Dougl.) and white spruce (Picea glauca (Moench.) Voss) stands. The pine and spruce stands were planted on peat mineral soil mix placed over tailings sand and overburden substrates, respectively, in reclaimed oil sands sites in Alberta. We selected stands that form a productivity gradient (low, medium, and high productivities) of each tree species based on differences in tree height and diameter at breast height (DBH) increments. In lodgepole pine stands, fine root length density and fine root production, and turnover rates were in the order of high > medium > low productivity sites and were positively correlated with tree height and DBH and negatively correlated with soil salinity (P productivity gradient and was negatively correlated with soil compaction. In conclusion, fine root dynamics along the stand productivity gradients were closely linked to stand productivity and were affected by limiting soil properties related to the specific substrate used for reconstructing the reclaimed soil. Understanding the impact of soil properties on fine root dynamics and overall stand productivity will help improve land reclamation outcomes.

  11. Initial geochemical characteristics of fluid fine tailings in an oil sands end pit lake

    Energy Technology Data Exchange (ETDEWEB)

    Dompierre, Kathryn A. [Department of Civil and Geological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5A9 (Canada); Lindsay, Matthew B.J., E-mail: matt.lindsay@usask.ca [Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Cruz-Hernández, Pablo [Department of Geology, University of Huelva, Campus ‘El Carmen’, E-21071 Huelva (Spain); Halferdahl, Geoffrey M. [Environmental Research and Development, Syncrude Canada Limited, Edmonton, Alberta T6N 1H4 (Canada)

    2016-06-15

    Geochemical characteristics of fluid fine tailings (FFT) were examined in Base Mine Lake (BML), which is the first full-scale demonstration oil sands end pit lake (EPL) in northern Alberta, Canada. Approximately 186 Mm{sup 3} of FFT was deposited between 1994 and 2012, before BML was established on December 31, 2012. Bulk FFT samples (n = 588) were collected in July and August 2013 at various depths at 15 sampling sites. Temperature, solid content, electrical conductivity (EC), pH, Eh and alkalinity were measured for all samples. Detailed geochemical analyses were performed on a subset of samples (n = 284). Pore-water pH decreased with depth by approximately 0.5 within the upper 10 m of the FFT. Major pore-water constituents included Na (880 ± 96 mg L{sup −1}) and Cl (560 ± 95 mg L{sup −1}); Ca (19 ± 4.1 mg L{sup −1}), Mg (11 ± 2.0 mg L{sup −1}), K (16 ± 2.3 mg L{sup −1}) and NH{sub 3} (9.9 ± 4.7 mg L{sup −1}) were consistently observed. Iron and Mn concentrations were low within FFT pore water, whereas SO{sub 4} concentrations decreased sharply across the FFT–water interface. Geochemical modeling indicated that FeS{sub (s)} precipitation was favoured under SO{sub 4}-reducing conditions. Pore water was also under-saturated with respect to gypsum [CaSO{sub 4}·2H{sub 2}O], and near saturation with respect to calcite [CaCO{sub 3}], dolomite [CaMg(CO{sub 3}){sub 2}] and siderite [FeCO{sub 3}]. X-ray diffraction (XRD) suggested that carbonate-mineral dissolution largely depleted calcite and dolomite. X-ray absorption near edge structure (XANES) spectroscopy revealed the presence of FeS{sub (s)}, pyrite [FeS{sub 2}], and siderite. Carbonate-mineral dissolution and secondary mineral precipitation have likely contributed to FFT dewatering and settlement. However, the long-term importance of these processes within EPLs remains unknown. These results provide a reference for assessing the long-term geochemical evolution of oil sands EPLs, and offer

  12. Four-season variation of 2014 year in the surface sediments of the Gochang beach, southwestern coast of Korea

    Science.gov (United States)

    Ryang, Woo Hun; Kang, Sol-Ip

    2015-04-01

    The marco-tide, open-coast Gochang beach, located on the southwestern coast of Korea, was studied in terms of four season variations in surface sediment and sedimentary environment. During the four seasons of winter (February), spring (May), summer (August), and fall (November) in 2014 year, surface sediments of total 252 sites were sampled across three survey lines, consisting of 21 sites at 30 m intervals in each transverse line to the coast, respectively. The Gochang beach comprises the Dongho, Kwangseungri, and Myeongsasipri beaches from north to south. The pocket-type Dongho beach is mainly composed of very fine sands to very coarse sands, and the ratio of fine sand is the largest. The average of grain size is the coarsest in the winter. The spatial distribution of surface sediments shows a coast-parallel trend of fine and medium sands during the four seasons. During the winter, the upper tidal flat was dominated by medium sand, while the lower tidal flat was dominated by find sand. The surface sediments of the Kwangseungri beach are mainly composed of fine-grained sands, and the mean grain size is the coarsest in winter. Grain-size distribution shows a uni-mode pattern in the four seasons. Mud facies partly exist in spring and summer seasons, whereas it is rarely shown in autumn and winter. The spatial distribution of surface sediments shows a coast-parallel trend of fine to coarse sand during the four seasons. The Myeongsasipri beach is mainly composed of very fine sands to very coarse sands, and the ratio of fine sand is the largest. Grain-size distribution shows a weak bi-modal trend in the autumn and a uni-mode pattern in the spring, summer and winter. The mean grain size of the winter is the coarsest among those of four seasons. The spatial distribution of four seasons also shows a coast-parallel trend. During the four seasons of 2014 year in the Gochang beach, overall distribution of the grain sizes represents a fining trend from upper to lower tidal

  13. Short to long-term evolution of the shoreline and the subaerial sand beach driven by extreme forcings : Wan-Tzu-Liao, Taïwan

    Science.gov (United States)

    Campmas, Lucie; Bouchette, Frederic; Meulé, Samuel; Sous, Damien; Liou, Jiing-Yih; Leroux-Mallouf, Romain; Sabatier, François; Hwung, Hwung-Hweng

    2015-04-01

    This study aims at investigating the interactions between wave conditions, water level and morphology of a sand barrier driven by paroxysmal conditions over instantaneous swash event, storm event, monsoon/typhoons seasons and decadal time scales. In the framework of the KUN-SHEN project, 7 months of monitoring (2011-2012) provided 20 topobathymetric surveys (from the subtidal zone to the back-barrier) and acquisitions of offshore, nearshore and shallow water hydrodynamics including velocity profiling, free surface measurement and absolute pressure. Offshore waves were extracted at Cigu buoy (18 m of water depth). Nearshore waves were acquired from the current profiler deployed 400 m off the coast in 4 m of water depth and water level on the subaerial beach were acquired from pressure sensors deployed from the subtidal zone to the dune crest. Morphologic changes of the emerged beach were monitored using D-GPS each week during the winter monsoon season and just before and after each event during the summer typhoons season. The long-term shoreline changes (1993-2009) of the sand barrier is based on aerial photographs and satellites images. The short-term study focus on the sand bed elevation changes associated with individual swash events during the most energetic storm recorded. During this Talim tropical storm (offshore significant wave height up to 10.3 m with period about 14.6 s), pressure sensors deployed in the subaerial beach display a sand bed nourishment about +3.02 cm/h during the storm rising. The numerous swash-swash interactions during the falling period of the storm appear more erosive. Morphological changes of Talim storm in the whole emerged beach included 6.7 m of dunefoot retreat and a sand transfer from a dune breach to wash-over deposits in the lagoon. Additionally, the foreshore was nourished +2261 m3 +/-268 m3 as well as the whole sand barrier (+1920 m3 +/-1071 m3). The summer season of typhoons appears to be an accretive period (3556 m3 +/-1071

  14. Distribution and structure of the upper sublittoral macrobenthic communities of Tróia sand beaches (Setúbal, Portugal) and their relationship with environmental factors.

    Science.gov (United States)

    Vale, Maria; Cabral, Henrique; Andrade, Francisco

    2010-04-01

    The present study dealt with the spatial and temporal variability of the distribution of the upper sublittoral benthic macrofauna of the Tróia peninsula sand beaches and its relationship with abiotic environmental factors. The existence of a relationship between the data set of macrobenthic species distribution and community structure in the Sado estuary (432 individual samples) and the environmental factors in analysis was investigated. Morpho-sedimentary data analysis revealed an environmental gradient, from the marine margin (exposed marine environment) to the estuarine margin (sheltered estuarine environment). Benthic macrofauna analysis showed a gradient of increasing number of individuals, species richness and diversity from the marine margin (Exposed) to the estuarine margin (Sheltered). Canonical Correspondence Analysis showed the dominant patterns in the community structure to be explained by the environmental factors considered, the most important, of which in influencing the spatial and temporal pattern, being beach slope, organic matter and calcium carbonate contents. The structure of the sandy beach communities studied showed a clear dominance of the spatial patterns over the seasonal ones. Four assemblages were defined-(1) an assemblage dominated by Angulus tenuis, on the marine margin of the peninsula; (2) an assemblage dominated by Euclymene sp. and Apseudes latreillei, on the sea-estuary transition area and related to the presence of a Zostera spp. meadow; (3) an assemblage dominated by Glycera sp. and Scoloplos armiger, on the sea-estuary transition area; (4) an assemblage dominated by Notomastus latericeus, Nassarius reticulatus and Cyathura carinata, on the estuarine margin.

  15. Assessment of natural radioactivity of sands in beaches from Great Vitoria, ES, Brazil; Avaliacao da radioatividade natural em areias das praias da Grande Vitoria, ES

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Reginaldo Ribeiro de

    2010-07-01

    In this work the concentrations of natural radionuclides {sup 226}Ra, {sup 232}Th and {sup 40}K were determined in superficial sand samples for 16 locations throughout the coast of the Great Victory, metropolitan region of the state of Espirito Santo, Southeast of Brazil. The assessed beaches were Manguinhos and Jacaraipe in Serra county, Camburi, Praia do Canto and Curva da Jurema in Vitoria county, Praia da Costa and Itapua in Vila Velha county, Setibao, Setibinha, Praia do Morro, Praia das Castanheiras and Areia Preta in Guarapari county and sand of the Paulo Cesar Vinha Reserve also located in Guarapari county. Three sand samples of each beach were sealed in 100 mL high density polyethylene flasks. After approximately 4 weeks in order to reach secular equilibrium in the {sup 238}U and {sup 2}'3{sup 2}Th series, the samples were measured by high resolution gamma spectrometry and the spectra analyzed with the WinnerGamma software. The self absorption correction was performed for all samples. The {sup 226}Ra concentration was determined from the weighted average concentrations of {sup 214}Pb and {sup 21}'4Bi, the {sup 232}Th concentration was determined from the weighted average concentrations of {sup 228}Ac, {sup 2}'1{sup 2}Pb and {sup 212}Bi and the concentration of {sup 40}K is determined by its single gamma transition of 1460 keV. The radium equivalent concentration and the external hazard index where obtained from the concentrations of {sup 226}Ra, {sup 232}Th and {sup 4}'0K. {sup 226}Ra concentrations show values varying from 3 +- 1 Bq.kg-1 to 738 +- 38 Bq.kg{sup -1}, with the highest values for the central locality of the Camburi beach. {sup 232}Th concentrations show values varying from 7 +- 3 Bq.kg{sup -1} to 7422 +- 526 Bq.kg{sup -1}, with the highest values for Areia Preta beach. {sup 40}K concentrations show values varying from 14 +- 6 Bq.kg{sup -1} to 638 +- 232 Bq.kg{sup -1}, with the highest values for Areia Preta beach

  16. Initial geochemical characteristics of fluid fine tailings in an oil sands end pit lake.

    Science.gov (United States)

    Dompierre, Kathryn A; Lindsay, Matthew B J; Cruz-Hernández, Pablo; Halferdahl, Geoffrey M

    2016-06-15

    Geochemical characteristics of fluid fine tailings (FFT) were examined in Base Mine Lake (BML), which is the first full-scale demonstration oil sands end pit lake (EPL) in northern Alberta, Canada. Approximately 186Mm(3) of FFT was deposited between 1994 and 2012, before BML was established on December 31, 2012. Bulk FFT samples (n=588) were collected in July and August 2013 at various depths at 15 sampling sites. Temperature, solid content, electrical conductivity (EC), pH, Eh and alkalinity were measured for all samples. Detailed geochemical analyses were performed on a subset of samples (n=284). Pore-water pH decreased with depth by approximately 0.5 within the upper 10m of the FFT. Major pore-water constituents included Na (880±96mgL(-1)) and Cl (560±95mgL(-1)); Ca (19±4.1mgL(-1)), Mg (11±2.0mgL(-1)), K (16±2.3mgL(-1)) and NH3 (9.9±4.7mgL(-1)) were consistently observed. Iron and Mn concentrations were low within FFT pore water, whereas SO4 concentrations decreased sharply across the FFT-water interface. Geochemical modeling indicated that FeS(s) precipitation was favoured under SO4-reducing conditions. Pore water was also under-saturated with respect to gypsum [CaSO4·2H2O], and near saturation with respect to calcite [CaCO3], dolomite [CaMg(CO3)2] and siderite [FeCO3]. X-ray diffraction (XRD) suggested that carbonate-mineral dissolution largely depleted calcite and dolomite. X-ray absorption near edge structure (XANES) spectroscopy revealed the presence of FeS(s), pyrite [FeS2], and siderite. Carbonate-mineral dissolution and secondary mineral precipitation have likely contributed to FFT dewatering and settlement. However, the long-term importance of these processes within EPLs remains unknown. These results provide a reference for assessing the long-term geochemical evolution of oil sands EPLs, and offer insight into the chemistry of pore water released from FFT to the overlying water cover.

  17. Potential of natural gamma-ray spectrometry for mapping and environmental monitoring of black-sand beach deposits on the northern coast of Sinai, Egypt.

    Science.gov (United States)

    Aboelkhair, Hatem; Zaaeimah, Mostafa

    2013-04-01

    The concentrations and distributions of naturally occurring radioactive materials were studied with the aim of detecting and mapping radioactive anomalies as well as monitoring the environment for black-sand beach deposits in Northern Sinai, Egypt. For this purpose, ground gamma-ray spectrometric surveys were conducted using a portable GS-512 spectrometer, with an NaI (Tl) detector, on an area 77.5 km(2) in surface area located between the cities of Rafah and Elareish on the Mediterranean Sea coast. The results revealed that the black-sand beach deposits could be differentiated according to their total-count (TC) radioactivity into five normally distributed interpreted radiometric lithologic (IRL) units denoted by U1, U2, U3, U4 and U5. The computed characteristic TC radiometric statistics of these five IRL units range from 4.67  to 9.96 Ur for their individual arithmetic means. The computed arithmetic means for the three radioelements K, eU and eTh reach 0.46 %, 2.25 and 6.17 ppm, respectively for the whole study area. Monitoring the environmental effects of radioelement concentrations on the study area showed that the mean natural equivalent radiation dose rate from the terrestrial gamma-radiation of the whole area attains 0.33 mSv y(-1). This average value remains on the safe side and within the maximum permissible safe radiation dose (radioactive dose generated mainly by monazite and zircon minerals, two of the main constituents of black sands.

  18. Iron oxides and monazite from sands of two beaches in Espirito Santo, Brazil; Oxidos de ferro e monazita de areias de praias do Espirito Santo

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Flavia dos Santos; Couceiro, Paulo Rogerio da Costa; Lopes, Ana Lucia; Fabris, Jose Domingos [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: jdfabris@ufmg.br

    2005-04-01

    Sand samples collected from two sampling sites on Guarapari and Iriri beaches, state of Espirito Santo, Brazil, were studied in an attempt to better describe their chemical and mineralogical compositions and radioactive behaviors. The sands were found to contain about 6 (Guarapari) and 2 dag kg{sup -1} (Iriri) of rare earth and thorium that, if allocated to the monazite-(Ce) structure, lead to the averaged formulae Ce{sup 3+}{sub 0,494G}d{sup 3+}{sub 0,012}La{sup 3+}{sub 0,209}Nd{sup 3+}{sub 0,177}Pr{sup 3+}{sub 0,0=} 4{sub 0}Sm{sup 3+}{sub 0,024}Th{sup 4+}{sub 0,033} (PO{sub 4}) and Ce {sup 3+}{sub 0,474}La {sup 3+}{sub 0,227}Nd {sup 3+}{sub 0,190}Pr {sup 3+}{sub 0,044}Sm {sup 3+}{sub 0,032}Th{sup 4+}{sub 0,024} (PO{sub 4}). From Moessbauer spectroscopy data, the magnetic fractions of these sands were found to contain stoichiometric hematite (47.4 dag kg{sup -1}, from Guarapari, and 25.1 dag kg{sup -1}, from Iriri) and magnetite (44.1 and 58.8 dag kg{sup -1}). The specific {alpha} and {beta} radiation activities were also measured for both samples. (author)

  19. Modeling fine-scale geological heterogeneity-examples of sand lenses in tills

    DEFF Research Database (Denmark)

    Kessler, Timo Christian; Comunian, Alessandro; Oriani, Fabio;

    2013-01-01

    Sand lenses at various spatial scales are recognized to add heterogeneity to glacial sediments. They have high hydraulic conductivities relative to the surrounding till matrix and may affect the advective transport of water and contaminants in clayey till settings. Sand lenses were investigated o...

  20. Imidacloprid transport and sorption nonequilibrium in single and multilayered columns of Immokalee fine sand.

    Science.gov (United States)

    Leiva, Jorge A; Nkedi-Kizza, Peter; Morgan, Kelly T; Kadyampakeni, Davie M

    2017-01-01

    Imidacloprid (IMD) is a neonicotinoid pesticide soil-drenched to many crops to control piercing-sucking insects such as the Asian citrus psyllid (ACP). Neonicotinoids are persistent in the environment and transport analyses are helpful estimate leaching potential from soils that could result in groundwater pollution. The objective of this study was to analyze IMD breakthrough under saturated water flow in soil columns packed with three horizons (A, E, Bh) of Immokalee Fine Sand (IFS). Also, we used the dimensionless form of the convective-dispersive model (CD-Model) to compare the optimized transport parameters from each column experiment (retardation factor, R; fraction of instantaneous-to-total retardation, β; and mass transfer coefficient, ω) with the parameters obtained from sorption batch equilibria and sorption kinetics. The tracer (Cl-) breakthrough curves (BTCs) were symmetrical and properly described by the CD-Model. IMD BTCs from A, Bh, and multilayered [A+E+Bh] soil columns showed steep fronts and tailing that were well described by the one-site nonequilibrium (OSNE) model, which was an evidence of non-ideal transport due to IMD mass transfer into the soil organic matter. In general, IMD was weakly-sorbed in the A and Bh horizons (R values of 3.72 ± 0.04 and 3.08 ± 0.07, respectively), and almost no retardation was observed in the E horizon (R = 1.20 ± 0.02) due to its low organic matter content (0.3%). Using the HYDRUS-1D package, optimized parameters (R, β, ω) from the individual columns successfully simulated IMD transport in a multilayered column mimicking an IFS soil profile. These column studies and corresponding simulations agreed with previous findings from batch sorption equilibria and kinetics experiments, where IMD showed one-site kinetic mass transfer between soil surfaces and soil solution. Ideally, sandy soils should be maintained unsaturated by crop irrigation systems and rainfall monitoring during and after soil-drench application

  1. Numerical simulation of fine oil sand tailings drying in test cells

    NARCIS (Netherlands)

    Vardon, P.J.; Nijssen, T.; Yao, Y.; Van Tol, A.F.

    2014-01-01

    As a promising technology in disposal of mature fine tailings (MFT), atmospheric fines drying (AFD) is currently being implemented on a commercial scale at Shell Canada’s Muskeg River Mine near Fort McMurray, Alberta. AFD involves the use of a polymer flocculent to bind fine particles in MFT

  2. Pleistocene and holocene beaches and estuaries along the Southern Barrier of Buenos Aires, Argentina

    Science.gov (United States)

    Isla, Federico I.; Cortizo, Luis C.; Schnack, Enrique J.

    The Buenos Aires aggradation plain has a good record of Quaternary sea-level fluctuations. To the east of the Tandilia Range, the elevations of the Pleistocene beaches respond to the tectonic behaviour of the Salado Basin. Holocene beaches indicate a maximum transgression higher than 2 m. The low relief permitted an extended horizontal record of beach/chenier plains interfingered with estuarine environments (coastal lagoons, marshes) covered by a sandy (Eastern) barrier. Between the Tandilia and Ventania ranges, the location of Pleistocene and Holocene beaches are related to a former higher relief; i.e. they are attached to low-altitude cliffs and underneath cliff-top dunes composing the Southern Barrier. At Claromecó, Pleistocene gravel beaches, mostly composed of caliche pebbles, occur at heights between 4 and 7 m, and are overlying estuarine Pleistocene environments. Beaches of the same age are at a level of 10 m at Mar del Plata Harbour and Arroyo Sotelo (west of Mar Chiquita Lagoon). Holocene beaches found at Punta Mogotes and Costa Bonita are at higher altitudes than on the Eastern Barrier (ca. 2-4 m). The Holocene estuarine sequences are related laterally to present operating inlets (Las Brusquitas, La Ballenera, Quequén Grande, Claromecó, Quequén Salado). They are seldon thicker than 2.4 m, and comprise basal layers of black muds; towards the top, the layers are thinner, of coarser grain size and white colours. Grain-size analyses were performed comparatively on Pleistocene, mid-Holocene and present beaches. Sangamonian beaches aregravelly or coarser than medium sand (mean). Holocene beaches are usually coarser than medium sand, but dominantly shelly to the north of Mar del Plata, and composed of volcanic clasts to the south of this city. Modern beaches are dominated by fine sand, except at some erosive beaches between the Mar del Plata capes. They have a lesser content of shells than those of mid-Holocene.

  3. Specific activities and radiological hazard assessment in beach sand samples in Songkhla province, Thailand after Fukushima Dai-Ichi nuclear power plant accident in Japan

    Science.gov (United States)

    Kessaratikoon, P.; Boonkrongcheep, R.; Choosiri, N.; Daoh, M.; Udomsomporn, S.

    2017-06-01

    According to the Fukushima Dai-Ichi Nuclear Power Plant Accident in Japan on March 11, 2011, specific activities of natural (40K, 226Ra and 232Th) and anthropogenic (137Cs) radionuclides in 210 beach sand samples which were collected from Maharat, Sai Kaew, Samila, Chalatat, Na Thab, Sakom and Soi Sawan beaches in Songkhla Province along the eastern coast of Thailand, have been studied and evaluated. The specific activity levels of 40K, 226Ra, 232Th and 137Cs in the area were found in the range 110.13 - 4574.12, 6.99 - 451.87, 3.75 - 665.76 and 0.58- 9.91 Bq/Kg, respectively. Furthermore, the median values of specific activities of 40K, 226Ra, 232Th and 137Cs were calculated and compared with other research data in Thailand as well as global measurements and evaluations. Moreover, four radiological hazard indices for the studied area were also assessed by using the median values of specific activities of 40K, 226Ra and 232Th.

  4. Provenance of coastal dune sands along Red Sea, Egypt

    Indian Academy of Sciences (India)

    Samir M Zaid

    2017-06-01

    Texture, mineralogy, and major and trace element geochemistry of 26 coastal dune sand samples were studied to determine the provenance and tectonic environment of two dune fields close to the beaches of Safaga (SF) and Quseir (QS) at the Egyptian Red Sea coast. Onshore winds generate fine, moderate, moderately-well to well-sorted, coarse-skewed to near-symmetrical dune sands with mesokurtic distributions. Winds pick up and transport grains from nearby beach sands and alluvial deposits into a wide Red Sea coastal plain at the border of the beach. The mineralogical (Qt–Ft–Lt) and geochemical composition of the sands, indicate that SF and QS coastal dune sands are mature and influenced by quartz-rich sands. The average CIA values in SF and QS coastal dune sands are low relative to the range of the PAAS, suggesting an arid climate and a low intensity of chemical weathering. The SF and QS coastal dune sand samples are plotted in the recycled orogen and partly in craton interior fields suggesting recycled older sedimentary and partly metamorphic-plutonic sources. The high content of quartz with shell debris and carbonates in coastal dune sands support the recycled sedimentary beach and alluvial sand sources. The dominance of heavy minerals like amphiboles (hornblende) and biotite in the coastal dune sands also supports the effect of metamorphic-plutonic source rocks. The new tectonic discriminant-function diagrams suggest that the coastal dune sands were deposited in a passive margin of a synrift basin. The results provide a good evidence for the extension in the Red Sea rift system during Oligocene-post Pliocene, which is consistent with the general geology of Egypt.

  5. Effect of liming on yield and quality of peppermint and Sachalin mint in fine sand soil of Northern Finland

    Directory of Open Access Journals (Sweden)

    A. AFLATUNI

    2008-12-01

    Full Text Available Soil acidity commonly limits plant production in the fine sand soil of Northern Finland, which often has a low pH (5.5-6.5 and contains low levels of Ca and Mg. The effect of five liming (10% Mg and 19% Ca levels, 0, 4, 8, 12, and 16 tons ha -1 , on the herb and essential oil yield and menthol and menthone content of two mint species (peppermint, Mentha x piperita, a variety of Black Mitcham and Sachalin mint, Mentha arvensis var. sacchalinensis cultivated in fine sand soil in Northern Finland (6440’N and 2505’E was studied during 1998-2000. Liming clearly increased the pH levels and the Ca and Mg content of the soil. The dry matter content, essential oil quantity, and the menthol or menthone content in mints were not affected by liming. In comparison with no liming however, liming at a rate of 4 t ha -1 doubled the herb yield. The highest yield was achieved in Sachalin mint by liming at 4 or 8 t ha -1 in the second and third year (soil pH 6-6.5 (Ca 725-871 mg l -1 and Mg 122- 219 mg l -1 , and in peppermint by liming at 4, 8 or 16 t ha -1 (soil pH 6-6.6 (Ca 725-1272 mg l -1 and Mg 122-245 mg l -1 . Therefore, we conclude that a higher peppermint and Sachalin mint yield is achieved by increasing soil pH to values above 6.0 in the fine sand soil of Northern Finland.;

  6. Thin lift dewatering of oil sand tailings: optimizing dewatering of fluid fine tailings by controlling polymer mixing

    Energy Technology Data Exchange (ETDEWEB)

    Demoz, A.; Munoz, V.; Mikula, R. [Natural Resources Canada, CanmetENERGY, Devon, Alberta (Canada)

    2011-07-01

    In the oil sands industry, dewatering of tailings is an important issue. Recent work has shown that the addition of polymer helps to enhance dewatering of fluid fine tailings. High molecular weight polymers are used to bind small solids which results in a higher floc strength with no significant effect on water chemistry. The problem of this technique is that polymers only achieve optimal performance within a narrow window. This paper aimed at assessing the effect of mixing on the dewatering performance of polymer treatment on mature fine tailings. Tests were performed with different impeller types, mixing speeds and durations. Results demonstrated that the flocculation process is critical in the dewatering process and that working at the optimal flocculation conditions presents considerable benefits. This paper investigated the importance of mixing on the dewatering process and highlighted that further work has to be undertaken to optimize this process.

  7. Sources of organic compounds in fine soil and sand particles during winter in the metropolitan area of Riyadh, Saudi Arabia.

    Science.gov (United States)

    Rushdi, Ahmed I; Al-Mutlaq, Khalid; Simoneit, Bernd R T

    2005-11-01

    Major advances have been made in molecular marker analysis to distinguish between natural and anthropogenic organic matter inputs to the atmosphere. Resuspension of soil and sand by wind is one of the major mechanisms that produces particle dusts in the atmosphere. Soil and sand samples from the Riyadh area were collected in winter 2002, sieved to remove coarse particles and extracted with a mixture of dichloromethane and methanol (3:1, v:v). The total extracts were analyzed by gas chromatography-mass spectrometry in order to characterize the contents and identify the potential sources of the organic components. The major organic compounds of these extracts were derived from natural biogenic and anthropogenic sources. Organic compounds from natural sources, mainly vegetation, were major in samples from outside the city of Riyadh and included n-alkanes, n-alkanoic acids, n- alkanols, methyl alkanoates, and sterols. Anthropogenic inputs were significant in the fine particles of soil and sand samples collected from populated areas of the city. They consisted mainly of n-alkanes, hopanes, UCM (from vehicular emissions), and plasticizers (from discarded plastics, e.g., shopping bags). Carbohydrates had high concentrations in all samples and indicate sources from decomposed cellulose fibers and/or the presence of viable microbiota such as bacteria and fungi.

  8. Molecular and culture dependent characterization of endolithic bacteria in two beach sand samples and description of Rhizobium endolithicum sp. nov.

    Science.gov (United States)

    Parag, B; Sasikala, Ch; Ramana, Ch V

    2013-12-01

    Endolithic metagenome analysis of two beach samples collected form Chilika, Odisha, India indicated rich bacterial diversity. While the metagenome analysis of sample one yielded 16S rRNA gene sequences which represent six phyla and 16 genera, sample two yielded very rich diversity representing 17 phyla and 286 genera. Six species of bacteria were isolated from the endolithic enrichments and most of them have 16S rRNA gene sequence similarity of >99 % with known taxa, except for strain JC140(T) having Rhizobium yanglingense SH22623(T) (96.8 %), R. alkalisoli CCBAU 01393(T) (96.3 %), R. vignae CCBAU 05176(T) (96.2 %), R. mesosinicum CCBAU 25010(T) (96.1 %) and other members of the genus Rhizobium with Rhizobium for which, the name R. endolithicum sp. nov. is proposed. The type strain is JC140(T) (= KCTC32077(T) = CCUG64352(T) = MTCC11723(T) = HAMBI 2447(T)).

  9. A Conceptual Model for Spatial Grain Size Variability on the Surface of and within Beaches

    Directory of Open Access Journals (Sweden)

    Edith Gallagher

    2016-05-01

    Full Text Available Grain size on the surface of natural beaches has been observed to vary spatially and temporally with morphology and wave energy. The stratigraphy of the beach at Duck, North Carolina, USA was examined using 36 vibracores (~1–1.5 m long collected along a cross-shore beach profile. Cores show that beach sediments are finer (~0.3 mm and more uniform high up on the beach. Lower on the beach, with more swash and wave action, the sand is reworked, segregated by size, and deposited in layers and patches. At the deepest measurement sites in the swash (~−1.4 to −1.6 m NAVD88, which are constantly being reworked by the energetic shore break, there is a thick layer (60–80 cm of very coarse sediment (~2 mm. Examination of two large trenches showed that continuous layers of coarse and fine sands comprise beach stratigraphy. Thicker coarse layers in the trenches (above mean sea level are likely owing to storm erosion and storm surge elevating the shore break and swash, which act to sort the sediment. Those layers are buried as water level retreats, accretion occurs and the beach recovers from the storm. Thinner coarse layers likely represent similar processes acting on smaller temporal scales.

  10. Construction of an Environmentally Sustainable Development on a Modified Coastal Sand Mined and Landfill Site—Part 2. Re-Establishing the Natural Ecosystems on the Reconstructed Beach Dunes

    Directory of Open Access Journals (Sweden)

    Anne-Laure Markovina

    2010-03-01

    Full Text Available Mimicking natural processes lead to progressive colonization and stabilization of the reconstructed beach dune ecosystem, as part of the ecologically sustainable development of Magenta Shores, on the central coast of New South Wales, Australia. The retained and enhanced incipient dune formed the first line of storm defence. Placement of fibrous Leptospermum windrows allowed wind blown sand to form crests and swales parallel to the beach. Burial of Spinifex seed head in the moist sand layer achieved primary colonization of the reconstructed dune and development of a soil fungal hyphae network prior to introduction of secondary colonizing species. Monitoring stakes were used as roosts by birds, promoting re-introduction of native plant species requiring germination by digestive tract stimulation. Bush regeneration reduced competition from weeds, allowing native vegetation cover to succeed. On-going weeding and monitoring are essential at Magenta Shores until bitou bush is controlled for the entire length of beach. The reconstructed dunes provide enhanced protection from sand movement and storm bite, for built assets, remnant significant vegetation and sensitive estuarine ecosystems.

  11. Investigating the Microbial Degradation Potential in Oil Sands Fluid Fine Tailings Using Gamma Irradiation: A Metagenomic Perspective.

    Science.gov (United States)

    VanMensel, Danielle; Chaganti, Subba Rao; Boudens, Ryan; Reid, Thomas; Ciborowski, Jan; Weisener, Christopher

    2017-08-01

    Open-pit mining of the Athabasca oil sands has generated large volumes of waste termed fluid fine tailings (FFT), stored in tailings ponds. Accumulation of toxic organic substances in the tailings ponds is one of the biggest concerns. Gamma irradiation (GI) treatment could accelerate the biodegradation of toxic organic substances. Hence, this research investigates the response of the microbial consortia in GI-treated FFT materials with an emphasis on changes in diversity and organism-related stimuli. FFT materials from aged and fresh ponds were used in the study under aerobic and anaerobic conditions. Variations in the microbial diversity in GI-treated FFT materials were monitored for 52 weeks and significant stimuli (p tailings biogeochemistry and the impacts of GI treatment on microorganisms as an effect for targeting toxic organics. The outcomes of this study highlight the potential for this approach to accelerate stabilization and reclamation end points. Graphical Abstract.

  12. Assessment of Natural Radioactivity and radiation hazards in beach sand samples from Kanyakumari District, TamilNadu

    Science.gov (United States)

    Ajithra, A. K.; Shanthi, G.

    2016-07-01

    Natural radionuclides of terrestrial origin have very long half - lives or driven from very long - lived parent radionuclides, which have been created in stellar processes before the earth formation. The study of natural radioactivity in marine and coastal environments is of significant importance for better understanding of oceanographic and sedimentological processes. The sampling sites are selected to cover randomly to cover the southern part. The soil samples have been collected in beach sides. In situ gamma measurements were conducted using a high-purity germanium (HPGe) detector (coaxial cylinder of 50.1 mm in diameter and 44 mm in length) with a relative efficiency of 50% and an energy resolution (FWHM) of 1.8 keV at the 1.33 MeV reference transition of 60Co. The measurements shows that the values of the absorbed dose rates in air in the investigated area are lower than the recommended limit by the United Nations Scientific Committee on the Effect of Atomic Radiation.

  13. Chemical mass transport between fluid fine tailings and the overlying water cover of an oil sands end pit lake

    Science.gov (United States)

    Dompierre, Kathryn A.; Barbour, S. Lee; North, Rebecca L.; Carey, Sean K.; Lindsay, Matthew B. J.

    2017-06-01

    Fluid fine tailings (FFT) are a principal by-product of the bitumen extraction process at oil sands mines. Base Mine Lake (BML)—the first full-scale demonstration oil sands end pit lake (EPL)—contains approximately 1.9 × 108 m3 of FFT stored under a water cover within a decommissioned mine pit. Chemical mass transfer from the FFT to the water cover can occur via two key processes: (1) advection-dispersion driven by tailings settlement; and (2) FFT disturbance due to fluid movement in the water cover. Dissolved chloride (Cl) was used to evaluate the water cover mass balance and to track mass transport within the underlying FFT based on field sampling and numerical modeling. Results indicated that FFT was the dominant Cl source to the water cover and that the FFT is exhibiting a transient advection-dispersion mass transport regime with intermittent disturbance near the FFT-water interface. The advective pore water flux was estimated by the mass balance to be 0.002 m3 m-2 d-1, which represents 0.73 m of FFT settlement per year. However, the FFT pore water Cl concentrations and corresponding mass transport simulations indicated that advection rates and disturbance depths vary between sample locations. The disturbance depth was estimated to vary with location between 0.75 and 0.95 m. This investigation provides valuable insight for assessing the geochemical evolution of the water cover and performance of EPLs as an oil sands reclamation strategy.

  14. INFLUENCE OF TIDE AND WAVES ON WASHOUT OF DISSOLVED NUTRIENTS FROM THE BIOREMEDIATION ZONE OF A COARSE-SAND BEACH: APPLICATION IN OIL-SPILL BIOREMEDIATION

    Science.gov (United States)

    Successful bioremediation of oil-contaminated beaches requires maintenance of a sufficient quantity of growth-limiting nutrients in contact with the oiled beach materials. A conservative tracer study was conducted on a moderate-energy, sandy beach on Delaware Bay to estimate the...

  15. INFLUENCE OF TIDE AND WAVES ON WASHOUT OF DISSOLVED NUTRIENTS FROM THE BIOREMEDIATION ZONE OF A COARSE-SAND BEACH: APPLICATION IN OIL-SPILL BIOREMEDIATION

    Science.gov (United States)

    Successful bioremediation of oil-contaminated beaches requires maintenance of a sufficient quantity of growth-limiting nutrients in contact with the oiled beach materials. A conservative tracer study was conducted on a moderate-energy, sandy beach on Delaware Bay to estimate the...

  16. Bio-physicochemical effects of gamma irradiation treatment for naphthenic acids in oil sands fluid fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Boudens, Ryan; Reid, Thomas; VanMensel, Danielle; Sabari Prakasanm, M.R. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON (Canada); Ciborowski, Jan J.H. [Biological Sciences, University of Windsor, Windsor, ON (Canada); Weisener, Christopher G., E-mail: weisener@uwindsor.ca [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON (Canada)

    2016-01-01

    Naphthenic acids (NAs) are persistent compounds that are components of most petroleum, including those found in the Athabasca oil sands. Their presence in freshly processed tailings is of significant environmental concern due to their toxicity to aquatic organisms. Gamma irradiation (GI) was used to reduce the toxicity and concentration of NAs in oil sands process water (OSPW) and fluid fine tailings (FFT). This investigation systematically studied the impact of GI on the biogeochemical development and progressive reduction of toxicity using laboratory incubations of fresh and aged tailings under anoxic and oxic conditions. GI reduced NA concentrations in OSPW by up to 97% in OSPW and in FFT by 85%. The GI-treated FFT exhibited increased rates of biogeochemical change, dependent on the age of the tailings source. Dissolved oxygen (DO) flux was enhanced in GI-treated FFT from fresh and aged source materials, whereas hydrogen sulfide (HS{sup −}) flux was stimulated only in the fresh FFT. Acute toxicity to Vibrio fischeri was immediately reduced following GI treatment of fresh OSPW. GI treatment followed by 4-week incubation reduced toxicity of aged OSPW to V. fischeri. - Highlights: • Gamma irradiation substantially reduced concentrations of ecotoxic naphthenic acids • Acute toxicity was reduced in gamma irradiated process water • Gamma irradiated tailings exhibited increased rates of microbial respiration.

  17. Life on the beach for a sand crab (Emerita rathbunae (Decapoda, Hippidae: parasite-induced mortality of females in populations of the Pacific sand crab caused by Microphallus nicolli (Microphallidae

    Directory of Open Access Journals (Sweden)

    Juan Violante-González

    2016-09-01

    Full Text Available Parasites, by definition, can affect mortality of their host, making parasitism an important biotic determinant of animal population dynamics and community structure. Reduction in the number of larger, reproductive age females in populations of the Pacific sand crab, Emerita rathbunae (Decapoda, Hippidae, was observed in studies of the helminth community of this host. The aim of this study was to determine if high abundance of the metacercaria of the trematode, Microphallus nicolli (Microphallidae, causes mortality in this host. Females of E. rathbunae were collected from four sandy beaches in Guerrero State, Mexico, and helminths were collected from each crab. An analysis of variance (Anova was applied to these data in order to identify differences in abundance between sizes of crabs, and an analysis of covariance (Ancova was applied to identify differences in the abundance of metacercariae between locations. Parasite-related mortality was inferred by a decrease in abundance in older hosts. Linear and polynomial regressions of mean abundance of helminths (log x+1 transformed data vs. cephalothorax length of crabs were significant for the four populations of E. rathbunae, indicating increased mortality of older, more heavily infected female crabs and resultant removal from the population. Encapsulation and melanization of cysts by crabs was observed, indicating that an immune response by crabs also killed a portion of the cysts from subsequent exposures. Mortality of hosts through behavioral modification favoring transmission of highly infected crabs was suggested as the driving force behind this process.

  18. Provenance analysis of heavy minerals in beach sands (Falkland Islands/Islas Malvinas) - A view to mineral deposits and the geodynamics of the South Atlantic Ocean

    Science.gov (United States)

    Dill, Harald G.; Skoda, Radek

    2017-10-01

    Beach sands are ideal traps to collect heavy minerals (HM) from different geodynamic settings and mineral deposits. The coastal sediments contain a mixture of HM derived from the submarine shelf and from source rocks in the hinterland. This is true in a transgressive periglacial regime, where drowned valleys and estuaries are instrumental in draining HM to the arenaceous beach sediments from more distal basement lithologies. A scenario like this can be found in the Falkland Islands/Islas Malvinas. The site under study is the missing link between South Africa and South America, the splitting-apart of which is mirrored by the HM distribution predominantly concentrated in the backshore and dune belt along the coast. The HM are subdivided into three HM associations reflecting the geodynamic evolution of the South Atlantic Ocean and of some of the prominent mineral deposits on the Gondwana Continent: (1) Gondwana cratons and Proterozoic orogens, with Cr and BIF deposits (rutile, zircon, ilmenite, tourmaline, garnet, Cr spinel), (2) rift-related and break-apart magmatic lithologies with mantle-derived pipe rocks such as kimberlites (zircon, pyroxene, spinel, Mg ilmenite), (3) Cordillera-type lithologies with polymetallic stratabound deposits (tourmaline, amphibole, chlorite, REE phosphates). The variation of the major HM from the stable craton (Kalahari-Kaapvaal Craton) in the East to the mobile fold belt (Andes) in the West follows the order of stability of HM. In addition to these 3 geodynamic HM groups, sporadic occurrences of HM originating from alteration (leucoxene, chlorite s.s.s. (= solid solution series)) are part of armored relics such as ;nigrine; which on transport disintegrated and thereby released these HM. The major ultrastable and stable HM zircon, rutile, tourmaline s.s.s., spinel s.s.s., and garnet s.s.s. are displayed in a synoptical x-y plot showing the mantle and crustal trends of fractionation and formation of cumulates by means of particular

  19. Applied technique of the cemented fill with fly ash and fine-sands

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Traditional stabilization of backfilling material is done by using Portland cement. However, the high price of cement forced mining engineers to seek cheaper binding materials. Fly ash, which is the industrial waste from thermal power plant, possess the potential activity of jellification, and can be used in cemented fill as a partial substitute for cement to reduce the fill cost. Tests were done during the past few years in Xinqiao Pyrite Mine and Phoenix Copper Mine to determine the technology parameters and the suitable content of fly ash. Specimens with different cement/fly/ash tailings (sands) ratios were tested to obtain the strength values of the fill mass based on the analyses of both the chemical composition and physical and mechanical properties of fly ash. The compressive strength of specimens with a ratio of 1: 2: 8 (cement to fly ash to tailings)can reach 2 MPa after 90 d curing, totally meeting the requirement of artificial pillar and reducing the fill cost by 20%-30%.

  20. Silica nanoparticles for fines stabilization in Ottawa sand packed beds; Uso de nanopartículas de sílice para la estabilización de finos en lechos empacados de arena Ottawa

    Directory of Open Access Journals (Sweden)

    Farid Bernardo Cortes

    Full Text Available To determine the problem of fines migration on packed beds and offer a possible solution for this issue, an adsorptive system of packed beds was developed for experimental simulation of fines migration and stabilization by using silica nanoparticles. The adsorbent beds were prepared with Ottawa sand and glass spheres (average radius of 0.53 mm. Three different sand beds were used in the investigation: clean sand (water- wet system, sand submitted to a damage process using an extra-heavy Colombian crude oil (oil-wet system and sand treated with silica nanoparticles (5-15 nm. Fines suspension was prepared with alumina nanoparticles (50 nm and distilled water. Results show that beds treated with silica nanoparticles present idealized patterns for the rupture curve, indicating that silica nanoparticles capture and retain fines, decreasing fines migration due to their adsorption capacity.

  1. The discharge of fine silica sand in a silo under different ambient air pressures

    Science.gov (United States)

    Hsiau, Shu-San; Liao, Chun-Chung; Lee, Jie-Hsien

    2012-04-01

    Silos are widely used for the industrial scale handling and transportation of powdered and granular materials. The process of discharging powder in a silo involves the flow of both solid particles and an interstitial fluid, usually air. In this study, we experimentally investigate the effects of particle size and ambient pressure on the discharge process in open- and closed-top silos. The discharge rate, pressure drop, and pressure recovery rate are measured and discussed. The results show that the particle size, the diameter of the orifice, and the ambient pressure significantly influence the process of discharge. The effect of air flow is stronger on fine-powdered flow in a closed-top silo. The results indicate that the effects of air flow could be reduced by lowering the ambient pressure. In addition, a normalized critical pressure can be defined beyond which the discharge rate increases dramatically. With reduced ambient pressure, this normalized critical pressure decreases with increasing particle size. Finally, the experimental results are compared with results calculated using the Beverloo equation and Darcy's law.

  2. Variation of surface sediments in the Dongho beach before and after the typhoon Kompasu in 2010, southwestern coast of Korea

    Science.gov (United States)

    Ryang, Woo Hun; So, Kwang-Suk

    2015-04-01

    The Dongho beach, located on the southwestern coast of Korea, is marco-tide, open-coast, and pocket-type. In the Dongho beach, this study has focused on the typhoon effects of topography, surface sediment, and sedimentary environment, appeared before and after the typhoon Kompasu in 2010. The typhoon Kompasu moved along the southwestern coasts and across midlands of the Korean Peninsula from 1 to 2 September in 2010. Coastal effect of the moving typhoon was investigated in terms of the surface variations of surface sediment facies and sedimentary environment. Surface topography and sediments before and after the typhoon (August - September 2010) were measured and sampled along the Dongho survey line of 23 sites, respectively. The surface topography in the mid-to-low tidal zone became low after the typhoon rather than that before the typhoon. The lower topographic change is indicative of surface sediment erosion caused by the typhoon wave. The pocket-type Dongho beach is mainly composed of fine to coarse sands, and the ratio of fine sand is the largest. The spatial distribution of surface sediments shows a coast-parallel band of fine and medium sands during three seasons of spring, fall, and winter, whereas medium sands dominated in the northern part of the study area during the summer. Before the typhoon, spatial distribution pattern of sedimentary facies showed a trend of coast-parallel bands of fine sand facies and medium sand facies, whereas that after the typhoon was partly different. Keywords: coastal effect, Typhoon Kompasu in 2010, surface sediment, macro-tide, beach Acknowledgements: This research was supported by the Korea Institute of Marine Science and Technology Promotion (KIMST) through the project grant of Tracking and Prediction on Impacts of Ancient Extreme Climatic Events in the West and South Coastal Zone of Korea and by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education

  3. The well sorted fine sand community from the western Mediterranean Sea: A resistant and resilient marine habitat under diverse human pressures.

    Science.gov (United States)

    Dauvin, Jean-Claude; Bakalem, Ali; Baffreau, Alexandrine; Delecrin, Claire; Bellan, Gérard; Lardicci, Claudio; Balestri, Elena; Sardá, Rafael; Grimes, Samir

    2017-02-18

    The Biocoenosis of Well Sorted Fine Sands (WSFS) (SFBC, Sables Fins Bien Calibrés in French) is a Mediterranean community very well delimited by bathymetry (2-25 m) and sedimentology (>90% of fine sand) occurring in zones with relatively strong hydrodynamics. In this study focused on sites located along the Algerian, French, Italian and Spanish coasts of the Western Basin of the Mediterranean Sea (WBMS) we aim to compare the structure, ecological status and diversity of the macrofauna of the WSFS and examine the effects of recent human pressures on the state of this shallow macrobenthic community. We assess the ecological status and functioning of these WSFS using three categories of benthic indices: a) five indices based on classification of species into ecological groups, AMBI, BO2A, BPOFA, IQ and IP, b) the ITI index based on classification of species in trophic groups, and c) the Shannon H' index, and the Biological Traits Analysis (BTA), which is an alternative method to relative taxon composition analysis and integrative indices. Cluster analyses show that each zone show a particular taxonomic richness and dominant species. The seven benthic indices reveal that the macrobenthos of the WSFS of the four coastal zones show good or high Quality Status, except for one location on the Algerian coast (the Djendjen site) in 1997. BTA highlights the presence of three groups of species: 1) typical characteristic species; 2) indicator species of enrichment of fine particles and organic matter, and 3) coarse sand species which are accessorily found on fine sand. Finally, the WSFS which are naturally subject to regular natural physical perturbations show a high resilience after human pressures but are very sensitive to changes in the input of organic matter.

  4. Recent morphodynamics of a chenier beach in the Amazon-influenced mud-bank setting of Suriname, South America.

    Science.gov (United States)

    Anthony, Edward; Brunier, Guillaume; Hiwat, Micheal; Bilo, Karin

    2017-04-01

    The 350-km long coast of Suriname is part of a unique system in the world characterized by large-scale muddy sedimentation and chenier development. The mud is organized into discrete banks migrating alongshore under the influence of waves and currents, separated by 'inter-bank' zones, where cheniers commonly form. Braamspunt beach is a fine example of an open-coast chenier between the mouths of the Maroni and the Suriname Rivers. The former is the primary sand source for the beach, whereas the latter, near which the presently subsisting remnant of the beach is situated, forms a downdrift sink zone for this chenier. Satellite images between 1987 and 2016 shows that Braamspunt beach has significantly shortened over this period. This process has resulted from much of the sand supply coming from updrift (the Maroni) being integrated into a chenier driven landward by waves over mangroves and becoming overwhelmed by a mud bank migrating between the Maroni and Suriname Rivers. Two ground (hydrodynamics, GPS) and drone-photogrammetry surveys in 2016 show that Braamspunt beach is characterized by clear-cut longshore morphodynamic variations reflecting between the 'source' and the 'sink' zones. This gradient is related to different updrift (approaching mud bank) and downdrift (approaches to the Suriname estuary) contexts. The northern sector comprised two elements: the leading edge of the mud bank where the existing chenier (former open beach) has been isolated from the sea by mud and fossilized inland, and the 'terrestrial' shoreline junction with the leading edge of the mud bank. The latter segment consisted of a narrow 150 m-long sandy chenier migrating landward as mud has gained ground, resulting in shortening of the beach. As the chenier migrated inland over back-beach stands of Avicennia germinans mangroves, it left in its wake a muddy foreshore with subsisting mangroves that were part of the muddy mangrove-colonized muddy plain. The southern sector also comprised two

  5. Programs to obtain vertical heights from mean sea level and for computing volume of sand/mineral along beaches:A case study with Kalbadevi beach profiling data and results.

    Digital Repository Service at National Institute of Oceanography (India)

    Ganesan, P.

    profile studies with collection of field data. The main purpose for undertaking this study was to compare the beach profiles done at different periods, using the newly developed programs in GWBASIC language. The benchmark pillars were established...: --------------------------------------------------------------------------------------------------------------------- Bench mark Position in Position in Remarks Pillar No WGS-1984 Indian -1975 Latitude (N) Longitude (E) Latitude (N) Longitude (E) BP - 1...

  6. Óxidos de ferro e monazita de areias de praias do Espírito Santo Iron oxides and monazite from sands of two beaches in Espirito Santo, Brazil

    Directory of Open Access Journals (Sweden)

    Flávia dos Santos Coelho

    2005-03-01

    Full Text Available Sand samples collected from two sampling sites on Guarapari and Iriri beaches, state of Espírito Santo, Brazil, were studied in an attempt to better describe their chemical and mineralogical compositions and radioactive behaviors. The sands were found to contain about 6 (Guarapari and 2 dag kg-1 (Iriri of rare earth and thorium that, if allocated to the monazite-(Ce structure, lead to the averaged formulae Ce3+0,494Gd3+0,012La3+0,209Nd3+0,177Pr3+0,040Sm3+0,024Th4+0,033 (PO4 and Ce3+0,474La3+0,227Nd3+0,190Pr3+0,044Sm3+0,032Th4+0,024 (PO4. From Mössbauer spectroscopy data, the magnetic fractions of these sands were found to contain stoichiometric hematite (47.4 dag kg-1, from Guarapari, and 25.1 dag kg-1, from Iriri and magnetite (44.1 and 58.8 dag kg-1. The specific alpha and beta radiation activities were also measured for both samples.

  7. Microbial contamination of sand from major beaches in Fortaleza, Ceará State, Brazil Contaminação microbiológica da areia de algumas praias de Fortaleza,Ceará, Brasil

    Directory of Open Access Journals (Sweden)

    Regine Helena Silva dos Fernandes Vieira

    2001-06-01

    Full Text Available The presence of faecal contamination and pathogenic microorganisms in samples of dry and wet sand collected from three major beaches in Fortaleza, Ceará State, Brazil: (Praia do Mucuripe, Praia do Futuro and Praia do Caça e Pesca, during the period of May 1999 to January 2000 was evaluated. Praia do Caça e Pesca had the highest incidence of E. coli in dry sand (56% followed by Praia do Mucuripe (28% and Praia do Futuro (16%. In wet sand, results were 48%, 28% and 24% for Praia do Caça e Pesca, Praia do Futuro and Praia do Mucuripe, respectively. Only two samples from Praia do Futuro, one from dry sand and another one from wet sand, were positive for Salmonella. V. parahaemolyticus was isolated from four samples from Praia do Caça e Pesca (two from dry-sand samples and two from wet-sand, one from Praia do Futuro (wet sand, and three and four from Praia do Mucuripe (wet and dry sand, respectively. Yeasts belonged to the Candida genus. Dry-sand samples presented higher yeast contaminations level than wet-sand ones. Praia do Futuro had the highest level of yeast contamination (41%, followed by Praia do Caça e Pesca (33% and Praia do Mucuripe (26%.No presente trabalho, avaliou-se a presença de contaminação fecal e de microrganismos patogênicos em areia seca e areia úmida de três praias de Fortaleza, Ceará: Praia do Mucuripe, Praia do Futuro e Praia do Caça e Pesca. A praia que apresentou maior índice de contaminação com E.coli em areia seca foi a do Caça e Pesca (56%, seguido das praias do Mucuripe (28% e Futuro (16%. Em areia úmida a ordem decrescente de contaminação por E. coli foi Praia da Caça e Pesca, Futuro e Mucuripe com 48%, 28% e 24% de contaminação, respectivamente. Salmonella foi isolada de duas amostras da Praia do Futuro, uma de areia seca e outra de areia úmida. V. parahaemolyticus foi isolado em 2 amostras de areia seca e 2 de úmida da Praia da Caça e Pesca. Esse patógeno foi isolado de uma amostra de areia

  8. Modeling the transport of shigella in silty and fine sand in shallow aquifers in Caostal area of bonny Niger delta; rivers state of Nigeria

    Directory of Open Access Journals (Sweden)

    Solomon Ndubuisi Eluozo

    2012-11-01

    Full Text Available Modeling the transport of shigella in silty and fine sand formation in shallow aquifer has been developed, the model were generated to monitor the transport of shigella in coastal area of bonny, as coastal environment  there are lots of  influence in the soil formation, the major variable were considered in the development of the theoretical model, this condition were assessed and were integrated , this variables were  considered and it  develop a system that generated the model equation since the microbes are  found to be in exponential phase ,because of high degree of porosity and permeability of the soil formation, the mathematical equation  were found to  consider  these variables to ensure it predict the rate of deposition of shigella in  silty and fine sand formation, the model developed predict the transport of shigella in the coastal area of bonny, Niger Delta area of Nigeria, the model will be one of the baseline to reduce high rate of shigella  in the study area, the study has also provide a design benchmark for practicing  engineers and scientist to ensure that thorough ground are provide by application of the these design model.  

  9. Haeundae beach in Korea: Seasonal-to-decadal wave statistics and impulsive beach responses to typhoons

    Science.gov (United States)

    Lee, Hee Jun; Do, Jong-Dae; Kim, Sun Sin; Park, Won-Kyung; Jun, Kicheon

    2016-12-01

    Haeundae Beach represents Korean pocket beaches that are currently erosional and dominated by summertime typhoons. The decadal wave characteristics 9 km offshore of Haeundae Beach were analyzed using the WAM model that was validated through the 2007 wave observations. The wave statistics modelled for 1979-2007 indicates that the seasonal mean significant wave height (H s) is highest (0.6-0.7 m) in summer due to typhoons, in contrast to the lowest (around 0.5 m) autumn analog. The wave direction is also pronouncedly seasonal with the principal bearings of SSW and NE in the summer and winter seasons, respectively. The WAM results additionally show that the H s has gradually increased over the region of Haeundae Beach since 1993. Beach profiling during June-November 2014 shows the opposite processes of the typhoon and fair-weather on beach sands. During a typhoon, foreshore sands were eroded and then accumulated as sand bars on the surf zone. In the subsequent fair-weather, the sand bars moved back to the beach resulting in the surf-zone erosion and foreshore accretion. A total of 5 cycles of these beach-wide sand movements yielded a net retreat (up to 20 m) of the shoreline associated with large foreshore erosion. However, the surf zone only slightly accumulated as a result of the sand cycles. This was attributed to the sand escape offshore from the westernmost tip of the beach. The present study may provide an important clue to understanding the erosional processes in Haeundae Beach.

  10. Hawaii Beach Monitoring Program: Beach Profile Data

    Science.gov (United States)

    Gibbs, Ann E.; Richmond, Bruce M.; Fletcher, Charles H.; Hillman, Kindra P.

    2001-01-01

    Coastal erosion is widespread and locally severe in Hawaii and other low-latitude areas. Typical erosion rates in Hawaii are in the range of 15 to 30 cm/yr (0.5 to 1 ft/yr; Hwang, 1981; Sea Engineering, Inc., 1988; Makai Ocean Engineering, Inc. and Sea Engineering, Inc.,1991). Recent studies on Oahu (Fletcher et al., 1997; Coyne et al., 1996) have shown that nearly 24%, or 27.5 km (17.1 mi) of an original 115 km (71.6 mi) of sandy shoreline (1940's) has been either significantly narrowed (17.2 km; 10.7 mi) or lost (10.3 km; 6.4 mi). Nearly one-quarter of the islands' beaches have been significantly degraded over the last half-century and all shorelines have been affected to some degree. Oahu shorelines are by far the most studied, however, beach loss has been identified on the other islands as well, with nearly 13 km (8 mi) of beach likely lost due to shoreline hardening on Maui (Makai Engineering, Inc. and Sea Engineering, Inc., 1991). Causes of coastal erosion and beach loss in Hawaii are numerous but, unfortunately, poorly understood and rarely quantified. Construction of shoreline protection structures limits coastal land loss, but does not alleviate beach loss and may actually accelerate the problem by prohibiting sediment deposition in front of the structures. Other factors contributing to beach loss include: a) reduced sediment supply; b) large storms; and, c) sea-level rise. Reduction in sand supply, either from landward or seaward (primarily reef) sources, can have a myriad of causes. Obvious causes such as beach sand mining and emplacement of structures that interrupt natural sediment transport pathways or prevent access to backbeach sand deposits, remove sediment from the active littoral system. More complex issues of sediment supply can be related to reef health and carbonate production which, in turn, may be linked to changes in water quality. Second, the accumulated effect of large storms is to transport sediment beyond the littoral system. Third

  11. Sanitary quality of sands from marine recreational beaches of São Paulo, Brazil Qualidade sanitária de areia de praias recreacionais em São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Maria Inês Zanoli Sato

    2005-12-01

    Full Text Available A sanitary evaluation of sand and water from 16 beaches of São Paulo State, Brazil, was undertaken during spring of 1997 and summer of 1998. Ninety six samples each of wet and dry sand and seawater were collected and analysed for fecal indicator bacteria. A parasitological examination and Candida albicans analysis were also performed in sand samples and F-specific bacteriophages were determined in seawater. Statistical analysis of the results demonstrated higher concentrations of fecal coliforms and fecal streptococci in dry sand during summer. Correlation analysis indicated a significant relationship between fecal indicator densities in wet sand and seawater. There was a significant correlation between the densities of fecal coliforms and fecal streptococci for both types of sand, and this correlation was higher in wet sand. Cysts and eggs of parasites were detected in 4.2% of the samples and Candida albicans was isolated in 18% of the samples. The high concentrations of fecal indicators detected in sand during summer demonstrate that there is a health risk to the users of these recreational areas and suggest the necessity of some criteria for microbiological control. Preventive measures, such as education campaings and some management actions are important precautionary measures.Foi realizada uma avaliação sanitária das águas e areias de 16 praias do litoral do Estado de São Paulo, Brasil, durante a primavera de 1997 e verão de 1998. Cento e noventa e duas amostras de areia seca e úmida, e 96 amostras de água do mar, foram coletadas e analisadas quanto à presença de bactérias indicadoras de contaminação fecal. Também foram realizados exames parasitológicos e análises de Candida albicans nas amostras de areia, e a determinação de bacteriófagos F-específicos nas amostras de água. A análise estatística dos resultados demonstrou concentrações mais elevadas de coliformes e estreptococos fecais na areia seca, durante o ver

  12. Characterization of physical mass transport through oil sands fluid fine tailings in an end pit lake: a multi-tracer study

    Science.gov (United States)

    Dompierre, Kathryn A.; Barbour, S. Lee

    2016-06-01

    Soft tailings pose substantial challenges for mine reclamation due to their high void ratios and low shear strengths, particularly for conventional terrestrial reclamation practices. Oil sands mine operators have proposed the development of end pit lakes to contain the soft tailings, called fluid fine tailings (FFT), generated when bitumen is removed from oil sands ore. End pit lakes would be constructed within mined-out pits with FFT placed below the lake water. However, the feasibility of isolating the underlying FFT has yet to be fully evaluated. Chemical constituents of interest may move from the FFT into the lake water via two key processes: (1) advective-diffusive mass transport with upward pore water flow caused by settling of the FFT; and (2) mixing created by wind events or unstable density profiles through the lake water and upper portion of the FFT. In 2013 and 2014, temperature and stable isotopes of water profiles were measured through the FFT and lake water in the first end pit lake developed by Syncrude Canada Ltd. Numerical modelling was undertaken to simulate these profiles to identify the key mechanisms controlling conservative mass transport in the FFT. Shallow mixing of the upper 1.1 m of FFT with lake water was required to explain the observed temperature and isotopic profiles. Following mixing, the re-establishment of both the temperature and isotope profiles required an upward advective flux of approximately 1.5 m/year, consistent with average FFT settling rates measured at the study site. These findings provide important insight on the ability to sequester soft tailings in an end pit lake, and offer a foundation for future research on the development of end pit lakes as an oil sands reclamation strategy.

  13. Speleothems and Sand Castles

    Science.gov (United States)

    Hance, Trevor; Befus, Kevin

    2015-01-01

    The idea of building sand castles evokes images of lazy summer days at the beach, listening to waves crash, enjoying salty breezes, and just unplugging for a while to let our inner child explore the wonderful natural toys beneath our feet. The idea of exploring caves might evoke feelings and images of claustrophobia or pioneers and Native…

  14. 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.

  15. Upper Cretaceous bioturbated fine-to-medium sands: A problem for deep-water exploration in Campos Basin, Offshore Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Carminatti, M.; Zimmermann, L.; Jahnert, R.; Pontes, C.

    1996-08-01

    The presence of bioturbation in oil-prone turbidite deposits has detained a better exploration of upper Cretaceous siliciclastic reservoirs in Campos Basin. Bioturbated sandstones have degraded their permo-porosity with impact in oil production. They occur associated to unbioturbated sandstones with similar seismic amplitude, becoming difficult to separate them in seismic mapping. A comprehensive study in order to reduce the exploratory risk must consider firstly the recognition of genetic facies association through cores, and secondly the calibration of sonic well-logs and seismic velocity sections with rock data. This study deals with sedimentary facies association. The range of main facies in such reservoirs includes: (1) medium-to-coarse siliciclastic sandstone with cross stratification; (2) fine-to-medium massive sandstone with thin traction carpets, bioturbated by opportunistic ichnofabrics and, (3) bioturbated, muddy, fine-to-medium, quartz-feldspatic and glauconitic sandstone over 60 in thick. The genetic facies associations suggest that the sandwich reservoirs were formed by high density turbidite currents deposited en masse or by thin traction carpets. The bioturbated sandstone was originated by reworking of bottom currents rich in nutrients and oxygen. Detritic and biogenic glauconite covered and/or filled bioturbations indicate a basinward movement of the bottom currents. The successive alternation of high-energy with low-energy ichnofabrics reflects cyclic variations in current velocities.

  16. Beach ridges and prograded beach deposits as palaeoenvironment records

    Science.gov (United States)

    Tamura, Toru

    2012-09-01

    resolution and continuity inherent to beach ridge and beach deposits. The plan-view geomorphic expression of beach ridges typically consists of ridge sets with multi-decadal intervals, whereas their internal sedimentary structures define shorter time scales. Records of beach sedimentation and erosion are likely to be reworked by episodic high-magnitude beach retreat, and the resultant record of the net progradation is likely to be sporadic and discontinuous. The height of sandy beach ridges is often variable due to differing degrees of aeolian sand accumulation, and they are thus not used as sea-level indicators unless purely wave-built. Gravel ridge height is a relatively reliable indicator of sea level, but can vary in response to storminess fluctuations. Subsurface sediment facies boundaries are preferred as sea-level indicators, and those proposed include: boundaries of aeolian/beach, foreshore/shoreface, and upper/lower shorefaces. Catastrophic events are expressed in both erosional and depositional records. Erosion surfaces, or scarp imprints, revealed in a cross section of beach deposits, indicate storm or tsunami events. However, erosional events are likely to rework previous records of sedimentation and even other erosional events, and thus the apparent history decoded from the resultant deposits tends to be biased. Several attempts for estimating the frequency and intensity of prehistoric cyclones rely on assumed relationships between the level of coarse sand beach ridges and cyclone inundation. The formative process of coarse sand ridges remains uncertain and needs to be clarified, as it constitutes the fundamental basis of these attempts. The growth rates of beach-ridge systems are expected to reflect fluctuations in river sediment discharge to the coast and in aeolian sand flux due to onshore winds, both of which are affected by climate change. Assessment of the growth rate is potentially improved by ground-penetrating radar survey of subsurface structure and by

  17. The effect of beach slope on tidal influenced saltwater intrusion

    Science.gov (United States)

    Zhao, Z.; Shen, C.; Jin, G.; Xin, P.; Hua, G.; Tao, X.; Zhao, J.

    2015-12-01

    Beach slope changes the tidal induced saltwater-freshwater circulations in coastal aquifers. However, the effect of beach slope on tidal influenced saltwater-freshwater mixing process is far from understood. Based on sand flume experiments and numerical simulations, we investigated the intrusion process of saltwater into freshwater under tidal forcing and variable beach slopes. The sand flume experiment results show that milder slope induces larger upper saline plume (USP) and seaward salt wedge interface (SWI) under tidal forcing. While, the steady state SWI keeps stagnant with different beach slopes. Consistent with the previous research, our numerical simulations also show a lager flux exchange across the milder beach induced by the tidal fluctuations. The groundwater table fluctuates more intensify with deeper beach slope. The next step of our study will pay attention to the effect of beach slope on the instability of USP which induces the salt-fingering flow.

  18. Fine-scale patterns of vegetation assembly in the monitoring of changes in coastal sand-dune landscapes

    Directory of Open Access Journals (Sweden)

    J. Honrado

    2010-02-01

    Full Text Available Understanding dune ecosystem responses to multi-scale environmental changes can provide the framework for reliable forecasts and cost-efficient protocols for detecting shifts in prevailing coastal dynamics. Based on the hypothesis that stress and disturbance interact as primary community controls in coastal dunes, we studied the fine-scale floristic assembly of foredune vegetation, in its relation to topography, along regional and local environmental gradients in the 200 km long coastline of northern Portugal, encompassing a major biogeographic transition in western Europe. Thirty topographic profiles perpendicular to the shoreline were recorded at ten sites along the regional climate gradient, and vegetation was sampled by recording the frequency of plant species along those profiles. Quantitative topographic attributes of vegetated dune profiles (e.g. length or height exhibited wide variations relatable to differences in prevailing coastal dynamics. Metrics of taxonomic diversity (e.g. total species richness and its additive beta component and of the functional composition of vegetation were highly correlated to attributes of dune topography. Under transgressive dynamics, vegetation profiles have fewer species, increased dominance, lower turnover rates, and lower total vegetation cover. These changes may drive a decrease in structural and functional diversity, with important consequences for resistance, resilience and other ecosystem properties. Moreover, differences in both vegetation assembly (in meta-stable dunes and response to increased disturbance (in eroding dunes between distinct biogeographic contexts highlight a possible decline in facilitation efficiency under extreme physical stress (i.e. under Mediterranean climate and support the significance of functional approaches in the study of local ecosystem responses to disturbance along regional gradients. Our results strongly suggest that assessing fine-scale community assembly can

  19. Coastal engineering: vol II. Harbor and beach problems

    OpenAIRE

    Massie, W.W.

    1986-01-01

    Ship motions, channel depth, channel width, ship maneuvering models, maneuverability improvement, total channel optimization, coastal sand transport, radiation stress, wave set-up, radiation stress gradient, tidal forces, turbulent forces, bottom friction forces, longshore current computations, early coastal transport formula, sand transport mechanisms, model coastal transport formula, coastal dynamics with single line theory, sand transport along a beach profile, coastal changes with multipl...

  20. Beach Volume Change Using Uav Photogrammetry Songjung Beach, Korea

    Science.gov (United States)

    Yoo, C. I.; Oh, T. S.

    2016-06-01

    Natural beach is controlled by many factors related to wave and tidal forces, wind, sediment, and initial topography. For this reason, if numerous topographic data of beach is accurately collected, coastal erosion/acceleration is able to be assessed and clarified. Generally, however, many studies on coastal erosion have limitation to analyse the whole beach, carried out of partial area as like shoreline (horizontal 2D) and beach profile (vertical 2D) on account of limitation of numerical simulation. This is an important application for prevention of coastal erosion, and UAV photogrammetry is also used to 3D topographic data. This paper analyses the use of unmanned aerial vehicles (UAV) to 3D map and beach volume change. UAV (Quadcopter) equipped with a non-metric camera was used to acquire images in Songjung beach which is located south-east Korea peninsula. The dynamics of beach topography, its geometric properties and estimates of eroded and deposited sand volumes were determined by combining elevation data with quarterly RTK-VRS measurements. To explore the new possibilities for assessment of coastal change we have developed a methodology for 3D analysis of coastal topography evolution based on existing high resolution elevation data combined with low coast, UAV and on-ground RTK-VRS surveys. DSMs were obtained by stereo-matching using Agisoft Photoscan. Using GCPs the vertical accuracy of the DSMs was found to be 10 cm or better. The resulting datasets were integrated in a local coordinates and the method proved to be a very useful fool for the detection of areas where coastal erosion occurs and for the quantification of beach change. The value of such analysis is illustrated by applications to coastal of South Korea sites that face significant management challenges.

  1. BEACH VOLUME CHANGE USING UAV PHOTOGRAMMETRY SONGJUNG BEACH, KOREA

    Directory of Open Access Journals (Sweden)

    C. I. Yoo

    2016-06-01

    Full Text Available Natural beach is controlled by many factors related to wave and tidal forces, wind, sediment, and initial topography. For this reason, if numerous topographic data of beach is accurately collected, coastal erosion/acceleration is able to be assessed and clarified. Generally, however, many studies on coastal erosion have limitation to analyse the whole beach, carried out of partial area as like shoreline (horizontal 2D and beach profile (vertical 2D on account of limitation of numerical simulation. This is an important application for prevention of coastal erosion, and UAV photogrammetry is also used to 3D topographic data. This paper analyses the use of unmanned aerial vehicles (UAV to 3D map and beach volume change. UAV (Quadcopter equipped with a non-metric camera was used to acquire images in Songjung beach which is located south-east Korea peninsula. The dynamics of beach topography, its geometric properties and estimates of eroded and deposited sand volumes were determined by combining elevation data with quarterly RTK-VRS measurements. To explore the new possibilities for assessment of coastal change we have developed a methodology for 3D analysis of coastal topography evolution based on existing high resolution elevation data combined with low coast, UAV and on-ground RTK-VRS surveys. DSMs were obtained by stereo-matching using Agisoft Photoscan. Using GCPs the vertical accuracy of the DSMs was found to be 10 cm or better. The resulting datasets were integrated in a local coordinates and the method proved to be a very useful fool for the detection of areas where coastal erosion occurs and for the quantification of beach change. The value of such analysis is illustrated by applications to coastal of South Korea sites that face significant management challenges.

  2. Age and morphodynamics of a sandy beach fronted by a macrotidal mud flat along the west coast of Korea: a lateral headland bypass model for beach-dune formation

    Science.gov (United States)

    Chang, Tae Soo; Hong, Seok Hwi; Chun, Seung Soo; Choi, Jeong-Heon

    2016-11-01

    The Dasari beach-dune system fronted by an intertidal mud flat is a typical example of numerous small beaches found both in embayments and along the open macrotidal west coast of Korea. The beach is frequently exposed to energetic wave action at high tide in winter. Although this coastal dune-sandy beach-intertidal mud flat system has previously been described, its origin and morphodynamic behavior has to date not been firmly established. To clarify these issues, elevation profiles and surficial sediment samples were collected seasonally along five monitoring transects across the tidal flat. In addition, box-cores as well as vibro- and drill-cores were acquired along the middle transect. Optically stimulated luminescence (OSL) and 14C- AMS (accelerator mass spectrometry) dating methods were applied to determine the age of the tidal flat, the beach and the dune deposits. The results show that Dasari beach is topographically composed of two distinct morphological and sedimentological sectors, comprising a high-tide sandy beach that merges seaward into an extensive low-tide tidal flat composed of mud. The transition between the two sectors is marked by a sharp break in slope and change in internal sedimentary structures. At the boundary, the subtle shoreward fining trend in mean grain size on the intertidal flat switches to a pronounced shoreward coarsening trend. Near the transition, mixing between the beach sand and the mud is observed. Another striking feature is a seasonal rotation of the beach system centered on the middle sector, with the northern sector eroding in winter and accreting in summer, and the southern sector accreting in winter and eroding in summer. The spatial grain-size pattern reveals that the beach is fed from the neighboring beach in the north by lateral headland bypassing, rather than onshore transport across the tidal flat, the intermittent lateral supply of sand explaining the seasonal rotation of the beach. Stratigraphically, the beach

  3. Age and morphodynamics of a sandy beach fronted by a macrotidal mud flat along the west coast of Korea: a lateral headland bypass model for beach-dune formation

    Science.gov (United States)

    Chang, Tae Soo; Hong, Seok Hwi; Chun, Seung Soo; Choi, Jeong-Heon

    2017-08-01

    The Dasari beach-dune system fronted by an intertidal mud flat is a typical example of numerous small beaches found both in embayments and along the open macrotidal west coast of Korea. The beach is frequently exposed to energetic wave action at high tide in winter. Although this coastal dune-sandy beach-intertidal mud flat system has previously been described, its origin and morphodynamic behavior has to date not been firmly established. To clarify these issues, elevation profiles and surficial sediment samples were collected seasonally along five monitoring transects across the tidal flat. In addition, box-cores as well as vibro- and drill-cores were acquired along the middle transect. Optically stimulated luminescence (OSL) and 14C- AMS (accelerator mass spectrometry) dating methods were applied to determine the age of the tidal flat, the beach and the dune deposits. The results show that Dasari beach is topographically composed of two distinct morphological and sedimentological sectors, comprising a high-tide sandy beach that merges seaward into an extensive low-tide tidal flat composed of mud. The transition between the two sectors is marked by a sharp break in slope and change in internal sedimentary structures. At the boundary, the subtle shoreward fining trend in mean grain size on the intertidal flat switches to a pronounced shoreward coarsening trend. Near the transition, mixing between the beach sand and the mud is observed. Another striking feature is a seasonal rotation of the beach system centered on the middle sector, with the northern sector eroding in winter and accreting in summer, and the southern sector accreting in winter and eroding in summer. The spatial grain-size pattern reveals that the beach is fed from the neighboring beach in the north by lateral headland bypassing, rather than onshore transport across the tidal flat, the intermittent lateral supply of sand explaining the seasonal rotation of the beach. Stratigraphically, the beach

  4. Analysis of beachgrass ecomorphodynamics and foredune morphology along US Pacific Northwest coastal sand dunes using a Bayesian network

    Science.gov (United States)

    Biel, R.; Hacker, S.; Ruggiero, P.

    2016-12-01

    Coastal dunes provide valuable infrastructure for mitigating flooding and erosion hazard exposure by dissipating wave energy. Although vegetation is essential for foredune establishment and growth by facilitating sand deposition and stabilization, few have examined how plant distribution and abundance relates to foredune morphology in the field. The US Pacific Northwest coastal dune system presents an excellent case study for examining ecomorphodynamic processes on sand dunes. It exhibits a diverse array of geomorphological conditions, including a range of dissipative to reflective beaches and highly varied foredune morphology. Ecologically, the region contains two invasive, dune-building beachgrasses of the same genus (Ammophila arenaria and A. breviligulata). To explore how geomorphological and ecological drivers alter foredune morphology, we used a Bayesian network to assess the role of nearshore bathymetry, sand supply (measured as shoreline change rate), and beachgrass species identity and density in determining foredune morphology. At a finer scale, we also examined whether beachgrass density and species identity altered sand accretion between 2012 and 2014 at multiple points across the foredune using a mixed model. Our Bayesian network analysis indicates that nearshore slope, shoreline change rate, beach width, and beachgrass density directly or indirectly affect foredune width, slope, and height. However, we observed no relationships between species identity and foredune morphology. When examining the finer-scale relationship between beachgrass density and sand accretion at points along the foredune, we found that sand accretion was correlated with beachgrass stem density in 2012, new stem growth between 2012 and 2014, beach width, and elevation. Moreover, A. arenaria accreted more sand than A. breviligulata on the foredune face, suggesting that subtle differences in beachgrass morphology or growth patterns may produce differing accretion patterns across

  5. Microbiology and biochemistry of placer rich beach sediment: Short-term response to small scale simulated mining

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, C.E.G.; Das, A.; Faria, D.; LokaBharathi, P.A.

    In order to understand the influence of sand mining on the bacterial community of a placer rich beach ecosystem, a mechanical disturbance was simulated in Kalbadevi beach, Ratnagiri. Core samples from dune, berm, high tide, mid tide and low tide...

  6. Study of effects of fines content on dynamic elastic modulus and damping ratio of saturated sand%细粒含量对饱和砂土动弹性模量与阻尼比的影响研究

    Institute of Scientific and Technical Information of China (English)

    王勇; 王艳丽

    2011-01-01

    With the GDS dynamic triaxial system, undrained dynamic triaxial tests on the saturated sand of different fines contents were performed; and effects of fines content on the dynamic elastic modulus and damping ratio were analyzed. Results show that the dynamic elastic modulus of sand decreases with increasing of fines content; but the trend is reversed beyond the critical value of fines content of 30%. The damping ratio of sand firstly increases and then decreases with increasing fines content at the same critical value of fines content of 30%. When fines content is less than 30%, the dynamic characteristics of sand is determined mainly by the coarse grains; the skeleton void ratio between coarse grains increases with the increase of fines content; and the ability to resist deformation under the same strain level weakens so that the elastic modulus decreases. Meanwhile, the stress wave propagation speed slows down because of the reduction of contact points between soil particles, hysteresis quality of the soil dynamic load response strengthens and the damping ratio increases; when the fines content is greater than 30%, the dynamic characteristics of sand is determined mainly by the fine grains; the interfine void ratio decreases with increasing of fines content; so that the dynamic properties of sand shows a reverse trend.%利用GDS循环三轴试验系统,进行一系列不同细粒含量砂土的不排水动三轴试验,研究细粒含量对饱和砂土动弹性模量与阻尼比的影响.试验结果表明,砂土的动弹性模量随细粒含量的增加而减小,但当超过细粒含量的临界值30%后,变化趋势则相反;阻尼比随着细粒含量的增加呈现先增大后减小的趋势,其细粒含量的临界值也为30%.当细粒含量小于30%时,砂土的动力特性主要由粗粒决定,粗粒间形成的骨架孔隙比随细粒含量的增加而增大,相同应变水平下抵抗变形的能力随之减弱,从而使动弹性模量减小.同

  7. Experimental study of surface texture and resonance mechanism of booming sand

    Institute of Scientific and Technical Information of China (English)

    QU; JianJun; ZHANG; KeCun; SUN; Bo; JIANG; ShengXiang; DONG; GuangRong; ZU; RuiPing; FANG; HaiYan

    2007-01-01

    The sound-producing mechanism of booming sand has long been a pending problem in the blown sand physics. Based on the earlier researches, the authors collected some silent sand samples from Tengger Desert, Australian Desert, Kuwait Desert, beaches of Hainan Island and Japanese coast as well as the soundless booming sand samples from the Mingsha Mountain in Dunhuang to make washing experiments. In the meantime the chemical corrosion experiment of glass micro-spheres, surface coating experiment and SEM examination were also conducted. The experimental results show that the sound production of booming sand seems to have nothing to do with the presence of SiO2 gel on the surface of sand grains and unrelated to the surface chemical composition of sand grains but is related to the resonance cavities formed by porous (pit-like) physical structure resulting from a number of factors such as wind erosion, water erosion, chemical corrosion and SiO2 gel deposition, etc. Its resonance mechanism is similar to that of Hemholz resonance cavity. Under the action of external forces, numerous spherical and sand grains with smooth surface and porous surface are set in motion and rub with each other to produce extremely weak vibration sound and then become audible sound by human ears through the magnification of surface cavity resonance. However the booming sands may lose their resonance mechanism and become silent sand due to the damping action caused by the invasion of finer particles such as dust and clay into surface holes of sand grains. Therefore, clearing away fine pollutants on the quartz grain surface is an effective way to make silent sand emit audible sound.

  8. Biofilm formation, gel and esp gene carriage among recreational beach Enterococci.

    Science.gov (United States)

    Asmat, Ahmad; Dada, Ayokunle Christopher; Gires, Usup

    2014-06-12

    Biofilm production, gel and esp gene carriage was enumerated among forty six vancomycin resistant enterococci (VRE) and vancomycin susceptible enterococci (VSE) beach isolates. A higher proportion (61.54%) of biofilm producers was observed among beach sand as compared to beach water enterococci isolates (30%) indicating that enterococci within the sand column may be more dependent on biofilm production for survival than their beach water counterparts. Correlation analysis revealed strongly negative correlation (r=-0.535, p=0.015) between vancomycin resistance and biofilm formation. Given the observation of high prevalence of biofilm production among beach sand and the concomitant absence of esp gene carriage in any of the isolate, esp gene carriage may not be necessary for the production of biofilms among beach sand isolates. On the whole beach sand and water isolates demonstrated clearly different prevalence levels of vancomycin resistance, biofilm formation, esp and gel gene carriage. Application of these differences may be found useful in beach microbial source tracking studies. Tested starved cells still produced biofilm albeit at lower efficiencies. Non-dividing enterococci in beach sand can survive extended periods of environmental hardship and can resume growth or biofilm production in appropriate conditions thus making them infectious agents with potential health risk to recreational beach users.

  9. Fine study on single sand body and measures for tapping the potential of residual oil during polymer flooding in Pubei reservoir of Daqing

    Science.gov (United States)

    Meng, Y. J.

    2016-08-01

    In order to effectively guide the narrow channel sand body oil fields to exploit, according to the sand body distribution characteristics and geological genesis of narrow channel sand body oil fields, the type of single sand body is clarified. By means of identification of logging curves and correlation of well-tie profile, the internal structure of single sand body is recognized. and then the remaining oil genesis, distribution characteristics and the potential areas for polymer flooding are clarified by combining numerical simulation technology and dynamic analysis technology, and the remaining oil potential tapping method is designed by taking into consideration various factors including the characteristics of the remaining oil, reservoir property and product dynamic character. The result shows that the single sand body is divided into five types including multiphase channel superposition, distributary channel, single channel, sheet sand and lenticular sand. Potential remaining oil mainly are distributed in thick oil layers of multiphase channel superposition type and distributary channel type in which channel sands were developed and sedimentary environment are stable inner front facies and lake regressive inner front facies. The remaining oil is developed by optimizing the parameters of polymer flooding and combining many different measures. The study provides technical support for the efficient exploration for polymer flooding.

  10. A Beach and Dune Community. 4-H Marine Science. Member's Guide. Activity I. MSp 1.

    Science.gov (United States)

    Auburn Univ., AL. Cooperative Extension Service.

    The investigation in this booklet is designed to provide 4-H members with opportunities to identify common plants and animals found on beaches and sand dunes and to determine the role of the plants and animals in this community. Learners are provided with a picture of a hypothetical beach and sand dune and a list of organisms (included in the…

  11. Shifts in the microbial community composition of Gulf Coast beaches following beach oiling.

    Directory of Open Access Journals (Sweden)

    Ryan J Newton

    Full Text Available Microorganisms associated with coastal sands serve as a natural biofilter, providing essential nutrient recycling in nearshore environments and acting to maintain coastal ecosystem health. Anthropogenic stressors often impact these ecosystems, but little is known about whether these disturbances can be identified through microbial community change. The blowout of the Macondo Prospect reservoir on April 20, 2010, which released oil hydrocarbons into the Gulf of Mexico, presented an opportunity to examine whether microbial community composition might provide a sensitive measure of ecosystem disturbance. Samples were collected on four occasions, beginning in mid-June, during initial beach oiling, until mid-November from surface sand and surf zone waters at seven beaches stretching from Bay St. Louis, MS to St. George Island, FL USA. Oil hydrocarbon measurements and NOAA shoreline assessments indicated little to no impact on the two most eastern beaches (controls. Sequence comparisons of bacterial ribosomal RNA gene hypervariable regions isolated from beach sands located to the east and west of Mobile Bay in Alabama demonstrated that regional drivers account for markedly different bacterial communities. Individual beaches had unique community signatures that persisted over time and exhibited spatial relationships, where community similarity decreased as horizontal distance between samples increased from one to hundreds of meters. In contrast, sequence analyses detected larger temporal and less spatial variation among the water samples. Superimposed upon these beach community distance and time relationships, was increased variability in bacterial community composition from oil hydrocarbon contaminated sands. The increased variability was observed among the core, resident, and transient community members, indicating the occurrence of community-wide impacts rather than solely an overprinting of oil hydrocarbon-degrading bacteria onto otherwise

  12. Research on Super Fine Sand Mortar Oerformance and Mixture Ratio of Masonry Mortar%特细砂砂浆性能及砌筑砂浆配合比研究

    Institute of Scientific and Technical Information of China (English)

    宓永宁; 王振国; 孙荣华; 赵津霆; 邵欣

    2014-01-01

    采用特细砂作为细骨料配制水泥砌筑砂浆,探求其质量是否能满足工程建设要求。通过试验研究了灰砂比、水泥用量、用水量、砂子用量等因素对特细砂砂浆性能的影响,并对砌筑砂浆配合比进行了设计。结果表明:用特细砂配制的砂浆7、28 d 抗压强度比用中砂配制的砂浆的强度小。灰砂比为1:2.8和1:3.2时,P. S42.5水泥配制的砂浆的抗压强度大于P. S32.5水泥配制的砂浆。砂浆强度与灰砂比密切相关,灰砂比是衡量砂浆强度的一个计算变量。粉煤灰掺量在30%以内,砂浆的抗压强度都比不掺粉煤灰时有所增大,掺量为10%的砂浆抗压强度增长的速率最快,其抗压强度也最大。%It mixed cement masonry mortar by using super fine sand as fine aggregate and explored whether the quality could meet the requirement in project construction. It researched the influence of the cement-sand ratio,dosage of cement,water and sand to the performances of fine sand mortar through experiment and designed the masonry mortar mixture. The results show that 7 days and 28 days compressive strength of mortar pre-pared with special fine sand are smaller than prepared with medium sand. Cement-sand ratio of 1: 1. 28 and 1: 1. 32,compressive strength of mortar prepared with P. S42. 5 cement is greater than prepared with P. S32. 5 cement. Mortar strength is closely related to the cement-sand ratio,and the cement-sand ratio is one of its calculation variables. When the dosage of fly ash is within 30% ,the compressive strength of mortar is greater than that of without mixing fly ash. For The dosage of 10% mortar,its compressive strength growth rate is the biggest and it has the biggest compressive strength.

  13. Understanding beach health throughout the Great Lakes-Entering a new era of investigations

    Science.gov (United States)

    ,

    2010-01-01

    For over a decade, the U.S. Geological Survey (USGS) has been a leader in the science of beach health. The overall mission of this work is to provide science-based information and methods that will allow beach managers to more accurately make beach closure and advisory decisions, understand the sources and physical processes affecting beach contaminants, and understand how science-based information can be used to mitigate and restore beaches and protect the public. The work consists of four science elements-real-time assessments; pathogens and microbial source tracking; coastal processes; and data analysis, interpretation, and communication - which are described in this fact sheet. Some of the key questions for USGS beach research are the following: Are there better ways to inform the public whether they can use a beach without risking their health? How do new rapid analytical methods compare to traditional methods for determining concentrations of fecal-indicator bacteria at beaches? Are pathogens present at beaches and, if so, how do they get to the beach, and what is their source? How do sand movement and wave action on the beach affect fecal-indicator-bacteria and pathogen concentrations in the lake water? What are the best indicators of pathogenic microorganisms? With so many potential sources of fecal contamination at a beach, what methods can be used to distinguish the contributions from humans? What characteristics of beaches contribute most to influencing bacterial indicator and pathogen concentrations in beach sands and groundwater?

  14. Sedimentary Characteristics of Buried Sand Layers Deposited in a Coastal Swamp in West Aceh, Indonesia, in the Early 15th Century

    Science.gov (United States)

    Morgan, T.; Monecke, K.; Meilianda, E.; Pilarczyk, J.; Rusydy, I.; Moena, A.; Muzhaffat, H.; Rais, A.; Yolanda, I. P.

    2016-12-01

    Sediment cores from the coastal region of West Aceh, Indonesia, an area largely affected by the December 2004 Sumatra Andaman earthquake and resulting Indian Ocean tsunami, preserve evidence of two buried sand layers of possible tsunamigenic origin deposited in the early 15th century. The study site is dominated by beach ridge morphology with an alternation of beach ridges and swales characteristic of long-term coastal progradation. We targeted a low-lying area landward of a prominent beach ridge that is thought to have formed in the aftermath of the last predecessor of the 2004 event, and marks the position of the coastline in the late 14th and early 15th century. Using a hand auger and plastic tubes, 80 core samples up to 2.5 m in depth were recovered. Sand samples were analyzed using a laser diffraction particle size analyzer and prepared for microfossil analysis. The swale deposits are mostly composed of peat and overlie shallow marine sands forming the base of the beach ridge plain. Within the uppermost centimeters, a number of cores show a <1 cm thick sand layer possibly deposited during tsunami inundation in 2004. Intercalated within the peat deposits we found two buried sand layers at a depth of 70-100 cm below the surface. The lower sand layer is 1-6 cm thick and could only be traced in a handful of cores; the upper layer is more widespread and consistently thicker, measuring 11-17 cm, with 5-14 cm of peat in between the two sand sheets. The sand layers consist of massive to normally graded fine to medium sand and show sharp upper and lower boundaries indicating abrupt depositional events. Grain size distributions of the 2004 tsunami sand as well as of buried sand layers match shoreface sediment samples retrieved in 10 m water depth, suggesting a predominantly offshore source. Based on initial radiocarbon ages and estimates of sedimentation rates, the two buried sand layers were deposited in the early 15th century and are separated by only a few decades.

  15. Fine-scale thermal adaptation in a green turtle nesting population

    Science.gov (United States)

    Weber, Sam B.; Broderick, Annette C.; Groothuis, Ton G. G.; Ellick, Jacqui; Godley, Brendan J.; Blount, Jonathan D.

    2012-01-01

    The effect of climate warming on the reproductive success of ectothermic animals is currently a subject of major conservation concern. However, for many threatened species, we still know surprisingly little about the extent of naturally occurring adaptive variation in heat-tolerance. Here, we show that the thermal tolerances of green turtle (Chelonia mydas) embryos in a single, island-breeding population have diverged in response to the contrasting incubation temperatures of nesting beaches just a few kilometres apart. In natural nests and in a common-garden rearing experiment, the offspring of females nesting on a naturally hot (black sand) beach survived better and grew larger at hot incubation temperatures compared with the offspring of females nesting on a cooler (pale sand) beach nearby. These differences were owing to shallower thermal reaction norms in the hot beach population, rather than shifts in thermal optima, and could not be explained by egg-mediated maternal effects. Our results suggest that marine turtle nesting behaviour can drive adaptive differentiation at remarkably fine spatial scales, and have important implications for how we define conservation units for protection. In particular, previous studies may have underestimated the extent of adaptive structuring in marine turtle populations that may significantly affect their capacity to respond to environmental change. PMID:21937495

  16. Can beaches survive climate change?

    Science.gov (United States)

    Vitousek, Sean; Barnard, Patrick L.; Limber, Patrick

    2017-04-01

    Anthropogenic climate change is driving sea level rise, leading to numerous impacts on the coastal zone, such as increased coastal flooding, beach erosion, cliff failure, saltwater intrusion in aquifers, and groundwater inundation. Many beaches around the world are currently experiencing chronic erosion as a result of gradual, present-day rates of sea level rise (about 3 mm/year) and human-driven restrictions in sand supply (e.g., harbor dredging and river damming). Accelerated sea level rise threatens to worsen coastal erosion and challenge the very existence of natural beaches throughout the world. Understanding and predicting the rates of sea level rise and coastal erosion depends on integrating data on natural systems with computer simulations. Although many computer modeling approaches are available to simulate shoreline change, few are capable of making reliable long-term predictions needed for full adaption or to enhance resilience. Recent advancements have allowed convincing decadal to centennial-scale predictions of shoreline evolution. For example, along 500 km of the Southern California coast, a new model featuring data assimilation predicts that up to 67% of beaches may completely erode by 2100 without large-scale human interventions. In spite of recent advancements, coastal evolution models must continue to improve in their theoretical framework, quantification of accuracy and uncertainty, computational efficiency, predictive capability, and integration with observed data, in order to meet the scientific and engineering challenges produced by a changing climate.

  17. Can beaches survive climate change?

    Science.gov (United States)

    Vitousek, Sean; Barnard, Patrick L.; Limber, Patrick W.

    2017-01-01

    Anthropogenic climate change is driving sea level rise, leading to numerous impacts on the coastal zone, such as increased coastal flooding, beach erosion, cliff failure, saltwater intrusion in aquifers, and groundwater inundation. Many beaches around the world are currently experiencing chronic erosion as a result of gradual, present-day rates of sea level rise (about 3 mm/year) and human-driven restrictions in sand supply (e.g., harbor dredging and river damming). Accelerated sea level rise threatens to worsen coastal erosion and challenge the very existence of natural beaches throughout the world. Understanding and predicting the rates of sea level rise and coastal erosion depends on integrating data on natural systems with computer simulations. Although many computer modeling approaches are available to simulate shoreline change, few are capable of making reliable long-term predictions needed for full adaption or to enhance resilience. Recent advancements have allowed convincing decadal to centennial-scale predictions of shoreline evolution. For example, along 500 km of the Southern California coast, a new model featuring data assimilation predicts that up to 67% of beaches may completely erode by 2100 without large-scale human interventions. In spite of recent advancements, coastal evolution models must continue to improve in their theoretical framework, quantification of accuracy and uncertainty, computational efficiency, predictive capability, and integration with observed data, in order to meet the scientific and engineering challenges produced by a changing climate.

  18. The Usumacinta-Grijalva beach-ridge plain in southern Mexico: a high-resolution archive of river discharge and precipitation

    Science.gov (United States)

    Nooren, Kees; Hoek, Wim Z.; Winkels, Tim; Huizinga, Annika; Van der Plicht, Hans; Van Dam, Remke L.; Van Heteren, Sytze; Van Bergen, Manfred J.; Prins, Maarten A.; Reimann, Tony; Wallinga, Jakob; Cohen, Kim M.; Minderhoud, Philip; Middelkoop, Hans

    2017-09-01

    The beach-ridge sequence of the Usumacinta-Grijalva delta borders a 300 km long section of the southern Gulf of Mexico coast. With around 500 beach ridges formed in the last 6500 years, the sequence is unsurpassed in the world in terms of numbers of individual ridges preserved, continuity of the record, and temporal resolution. We mapped and dated the most extensively accreted part of the sequence, linking six phases of accretion to river mouth reconfigurations and constraining their ages with 14C and OSL dating. The geomorphological and sedimentological reconstruction relied on lidar data, coring transects, GPR measurements, grain-size analyses, and chemical fingerprinting of volcanic glass and pumice encountered within the beach and dune deposits. We demonstrate that the beach-ridge complex was formed under ample long-term fluvial sediment supply and shorter-term wave- and aeolian-modulated sediment reworking. The abundance of fluvially supplied sand is explained by the presence of easily weatherable Los Chocoyos ignimbrites from the ca. 84 ka eruption of the Atitlán volcano (Guatemala) in the catchment of the Usumacinta River. Autocyclic processes seem responsible for the formation of ridge-swale couplets. Fluctuations in their periodicity (ranging from 6-19 years) are governed by progradation rate, and are therefore not indicative of sea level fluctuations or variability in storm activity. The fine sandy beach ridges are mainly swash built. Ridge elevation, however, is strongly influenced by aeolian accretion during the time the ridge is located next to the beach. Beach-ridge elevation is negatively correlated with progradation rate, which we relate to the variability in sediment supply to the coastal zone, reflecting decadal-scale precipitation changes within the river catchment. In the southern Mexican delta plain, the coastal beach ridges therefore appear to be excellent recorders of hinterland precipitation.

  19. The Usumacinta–Grijalva beach-ridge plain in southern Mexico: a high-resolution archive of river discharge and precipitation

    Directory of Open Access Journals (Sweden)

    K. Nooren

    2017-09-01

    Full Text Available The beach-ridge sequence of the Usumacinta–Grijalva delta borders a 300 km long section of the southern Gulf of Mexico coast. With around 500 beach ridges formed in the last 6500 years, the sequence is unsurpassed in the world in terms of numbers of individual ridges preserved, continuity of the record, and temporal resolution. We mapped and dated the most extensively accreted part of the sequence, linking six phases of accretion to river mouth reconfigurations and constraining their ages with 14C and OSL dating. The geomorphological and sedimentological reconstruction relied on lidar data, coring transects, GPR measurements, grain-size analyses, and chemical fingerprinting of volcanic glass and pumice encountered within the beach and dune deposits. We demonstrate that the beach-ridge complex was formed under ample long-term fluvial sediment supply and shorter-term wave- and aeolian-modulated sediment reworking. The abundance of fluvially supplied sand is explained by the presence of easily weatherable Los Chocoyos ignimbrites from the ca. 84 ka eruption of the Atitlán volcano (Guatemala in the catchment of the Usumacinta River. Autocyclic processes seem responsible for the formation of ridge–swale couplets. Fluctuations in their periodicity (ranging from 6–19 years are governed by progradation rate, and are therefore not indicative of sea level fluctuations or variability in storm activity. The fine sandy beach ridges are mainly swash built. Ridge elevation, however, is strongly influenced by aeolian accretion during the time the ridge is located next to the beach. Beach-ridge elevation is negatively correlated with progradation rate, which we relate to the variability in sediment supply to the coastal zone, reflecting decadal-scale precipitation changes within the river catchment. In the southern Mexican delta plain, the coastal beach ridges therefore appear to be excellent recorders of hinterland precipitation.

  20. Megascale rhythmic shoreline forms on a beach with multiple bars

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2008-06-01

    Full Text Available The study, carried out in 2003 and 2006 at the Lubiatowo Coastal ResearchStation (Poland, located on the non-tidal southern Baltic coast(tidal range < 0.06 m, focused on larger rhythmic forms (mega-cusps withwavelengths in the interval 500 m > Lc > 20 m. Statistical analyses of detailed shoreline configurations were performed mostly with the Discrete Wavelet Transformmethod (DWT. The beach is composed of fine sand with grain diameter D50 ≈ 0.22 mm, which produces 4 longshore sandbars and a gently sloping seabed with β = 0.015. The analysis confirms the key role of bars in hydro- and morphodynamic surf zone processes.The hypothesis was therefore set up that, in a surf zone with multiple bars, the bars and mega-scale shoreline rhythmic forms form one integrated physical system; experimental evidence to substantiate this hypothesis was also sought.In such a system not only do self-regulation processes include swash zone phenomena, they also incorporate processes in offshore surf zone locations.The longshore dimensions of large cusps are thus related to the distances between periodically active large bed forms (bars. The spatial dimension of bar system activity (number of active bars depends, at a given time scale, on the associated hydrodynamic conditions. It was assumed that such a time scale could include either the development and duration of a storm, or a period of stable, yet distinct waves, capable of remodelling the beach configuration.The indentation to wavelength ratio of mega-cusps for the studied non-tidal dissipative environment may be one order of magnitude greater than for mesotidal, reflective beaches.

  1. Effects of sedimentation on soil physical and chemical properties and vegetation characteristics in sand dunes at the Southern Dongting Lake region, China

    Science.gov (United States)

    Pan, Ying; Zhang, Hao; Li, Xu; Xie, Yonghong

    2016-11-01

    Sedimentation is recognized as a major factor determining the ecosystem processes of lake beaches; however, the underlying mechanisms, especially in freshwater sand dunes, have been insufficiently studied. To this end, nine belt transects from nine freshwater sand dunes, classified into low (28.1 m) based on their elevations in 1972, were sampled to investigate differences in sedimentation rate and soil and vegetation characteristics in Southern Dongting Lake, China. Sedimentation rate, soil sand content, and soil pH increased, whereas soil clay, fine silt, moisture (MC), organic matter (OM), total N, and total K content, in addition to the growth and biodiversity of sand dune plants generally decreased with decreasing belt transect elevation. Regression analyses revealed that the negative effects of sedimentation on the ecosystem functions of sand dunes could be attributed to higher fine sand content in deposited sediments and stronger inhibition of plant growth. These results are consistent with previous studies performed in coastal sand dunes, which highlights the importance of sedimentation in determining ecological processes.

  2. 粗砂-砾石海滩溢油污染的现场生物修复%Field-Scale Bioremediation of Coarse Sand-Gravel Beach Contaminated by Oil Spill

    Institute of Scientific and Technical Information of China (English)

    梁生康; 周平; 李广茹; 陈宇; 郭利果; 杨仕美; 吴亮

    2012-01-01

    在天津港六号码头的粗砂-砾石海滩进行了人工模拟溢油条件下的生物修复现场实验,考察了添加水溶性肥料、添加缓释肥料以及同时添加缓释肥料和石油烃降解菌等修复措施的有效性.结果表明,在120 d的修复时间内,同时添加缓释肥料和石油烃降解菌的体系石油烃生物降解常数(Ks)最高,达0.007 2 d-1,为对照体系的2.4倍,该体系中氮、磷浓度和石油烃降解菌数量在较长时间内都维持较高水平,表明接种的石油烃降解菌能够直接利用缓释肥料所释放出来的营养元素而快速生长繁殖;添加水溶性肥料的体系短期内氮、磷含量显著提高,石油烃降解菌密度明显增大,石油烃降解速率加快,Ks为对照试验池的1.8倍;而添加缓释肥料的体系氮、磷含量尽管明显高于对照体系,Ks却略低于对照体系,这可能是由于土著微生物无法直接利用缓释肥料所释放的营养元素,甚至其释放的尿素在局部形成高氨氮环境而抑制微生物的生长.%A series of field bioremediation experiments were undertaken on the coarse sand-gravel beach in Tianjin Port NO. 6 jetty, in which crude oil had been intentionally added into plots to simulate oil spill. The objectives were to evaluate the effectiveness of various bioremediation strategies, including addition of slow-release fertilize (SRF), addition of water-soluble fertilizer (WSF) and addition of SRF supplemented with oil-degrading bacteria (ODB). The results showed that the plots treated with addition of SRF and ODB had the highest biodegradation rate constant (ks) of hydrocarbons, which was as high as 0.007 2 d-1 and was 2.4 times that of the control plot, and accordingly the contents of dissolved nitrogen and phosphorus, as well as the density of ODB could keep a high level in a longer period of time. This indicated that ODB could directly utilize the nutrients realsed from SRF to multiply rapidly. The contents of

  3. Beach profiling studies at Yarada beach, Visakhapatnam, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ganesan, P.; Raju, N.S.N.

    keeping the May 2009 profile as the base reference, over which the values of other seasons are compared and is presented in Table 9(iii). �A program to compute the volume of sand along beach Profiles� (Ganesan, P., 2006) was used for computation of volumes...

  4. Tidal flow separation at protruding beach nourishments

    OpenAIRE

    Rademacher, Max; de Schipper, Matthieu A.; Swinkels, Cilia; MacMahan, Jamie H.; Reniers, Ad J.H.M.

    2017-01-01

    The article of record as published may be found at http://dx.doi.org/10.1002/2016JC011942 In recent years, the application of large-scale beach nourishments has been discussed, with the Sand Motor in the Netherlands as the first real-world example. Such protruding beach nourishments have an impact on tidal currents, potentially leading to tidal flow separation and the generation of tidal eddies of length scales larger than the nourishment itself. The present study examines the cha...

  5. Namibia : triaxial test on sand

    DEFF Research Database (Denmark)

    Steenfelt, Jørgen S.; Jacobsen, Kim P.

    In connection with a harbour project the friction angle of a fine sand is required. On Friday 13 March 1998 the Danish Geotechnical Institute (DGI) delivered app. 2.5 kg sand for testing at the Geotechnical Engineering Laboratory, Aalborg University. The present Data Report summarises the results...

  6. Faraday, Jets, and Sand

    NARCIS (Netherlands)

    Sandtke, M.; van der Meer, Roger M.; Versluis, Andreas Michel; Lohse, Detlef

    2003-01-01

    When a 6-mm layer of fine sand with an average grain size of 40 µm is poured into a cylindrical container and shaken vertically, thin jets are seen to emerge from an airy cloud of grains, almost like protuberances from the corona of the sun. A quasi two-dimensional setup reveals the jet-formation

  7. Beach Profile Locations

    Data.gov (United States)

    California Department of Resources — Beaches are commonly characterized by cross-shore surveys. The resulting profiles represent the elevation of the beach surface and nearshore seabed from the back of...

  8. Beach Profile Locations

    Data.gov (United States)

    California Department of Resources — Beaches are commonly characterized by cross-shore surveys. The resulting profiles represent the elevation of the beach surface and nearshore seabed from the back of...

  9. Wave energy level and geographic setting correlate with Florida beach water quality.

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Kelly, Elizabeth A

    2016-03-15

    Many recreational beaches suffer from elevated levels of microorganisms, resulting in beach advisories and closures due to lack of compliance with Environmental Protection Agency guidelines. We conducted the first statewide beach water quality assessment by analyzing decadal records of fecal indicator bacteria (enterococci and fecal coliform) levels at 262 Florida beaches. The objectives were to depict synoptic patterns of beach water quality exceedance along the entire Florida shoreline and to evaluate their relationships with wave condition and geographic location. Percent exceedances based on enterococci and fecal coliform were negatively correlated with both long-term mean wave energy and beach slope. Also, Gulf of Mexico beaches exceeded the thresholds significantly more than Atlantic Ocean ones, perhaps partially due to the lower wave energy. A possible linkage between wave energy level and water quality is beach sand, a pervasive nonpoint source that tends to harbor more bacteria in the low-wave-energy environment.

  10. Beach morphology and coastline evolution in the southern Bohai Strait

    Science.gov (United States)

    Zhang, Wei; Wu, Jianzheng; Li, Weiran; Zhu, Longhai; Hu, Rijun; Jiang, shenghui; Sun, Yonggen; Wang, Huijuan

    2015-10-01

    The beach studied in this paper spans a length of 51 km and is one of several long sandy beaches in the southern Bohai Strait. Due to the obstruction of islands in the northeast and the influence of the underwater topography, the wave environment in the offshore area is complex; beach types and sediment transport characteristics vary along different coasts. The coastlines extracted from six aerial photographs in different years were compared to demonstrate the evolving features. Seven typical beach profiles were selected to study the lateral beach variation characteristics. Continuous wind and wave observation data from Beihuangcheng ocean station during 2009 were employed for the hindcast of the local wave environment using a regional spectral wave model. Then the results of the wave hindcast were incorporated into the LITDRIFT model to compute the sediment transport rates and directions along the coasts and analyze the longshore sand movement. The results show that the coastline evolution of sand beaches in the southern Bohai Strait has spatial and temporal variations and the coast can be divided into four typical regions. Region (I), the north coast of Qimudao, is a slightly eroded and dissipative beach with a large sediment transport rate; Region (II), the southwest coast of Gangluan Port, is a slightly deposited and dissipative beach with moderate sediment transport rate; Region (III), in the central area, is a beach that is gradually transformed from a slightly eroded dissipative beach to a moderately or slightly strong eroded bar-trough beach from west to east with a relatively moderate sediment transport rate. Region (IV), on the east coast, is a strongly eroded and reflective beach with a weak sediment transport rate. The wave conditions exhibit an increasing trend from west to east in the offshore area. The distribution of the wave-induced current inside the wave breaking region and the littoral sediment transport in the nearshore region exhibit a gradual

  11. Beach and Morphology Change Using Lidar

    Science.gov (United States)

    2016-11-01

    were imported as (x, y, z) scatter points into the Scatter Module of the SMS (Figure 3) decimated by 5 meters (m) in the cross- shore and 50 m in...morphodynamics of sandy and mixed sand and gravel beaches. Graduate thesis and dissertation. Tampa, FL: University of South Florida. http...Engineers (USACE), Jacksonville District (SAJ). 2010. Pinellas County, Florida, shore protection project: Long Key & Treasure Island segments, 2006

  12. The influence of anthropic actions on the evolution of an urban beach: Case study of Marineta Cassiana beach, Spain.

    Science.gov (United States)

    Pagán, J I; Aragonés, L; Tenza-Abril, A J; Pallarés, P

    2016-07-15

    Coastal areas have been historically characterized as being a source of wealth. Nowadays, beaches have become more relevant as a place for rest and leisure. This had led to a very high population pressure due to rapid urbanisation processes. The impacts associated with coastal tourism, demand the development of anthropic actions to protect the shoreline. This paper has studied the impacts of these actions on the Marineta Cassiana beach, in Denia, Spain. This particular Mediterranean beach has traditionally suffered a major shoreline regression, and the beach nourishments carried out in the 1980s would not have achieved the reliability desired. This research has analysed the historic evolution of the beach and its environment for a period of 65years (1950-2015). A Geographic Information System (GIS) has been used to integrate and perform a spatial analysis of urban development, soil erosion, stream flow, swell, longshore transport, submerged vegetation species and shoreline evolution. The results show how the anthropic actions have affected the shoreline. After the excessive urban development of the catchments, there is no natural sediment supply to the beach. The change in the typology of the sediment, from pebbles to sand, during the beach nourishments has led to a crucial imbalance in the studied area. Moreover, the beach area gained has disappeared, affecting the Posidonia oceanica meadow, and incrementing the erosion rates. The findings obtained are relevant, not only in the management and maintenance of the beaches, but also, in the decision-making for future nourishments.

  13. Fontainebleau Sand

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    2006-01-01

    The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

  14. Beach science in the Great Lakes

    Science.gov (United States)

    Nevers, Meredith B.; Byappanahalli, Murulee N.; Edge, Thomas A.; Whitman, Richard L.

    2014-01-01

    Monitoring beach waters for human health has led to an increase and evolution of science in the Great Lakes, which includes microbiology, limnology, hydrology, meteorology, epidemiology, and metagenomics, among others. In recent years, concerns over the accuracy of water quality standards at protecting human health have led to a significant interest in understanding the risk associated with water contact in both freshwater and marine environments. Historically, surface waters have been monitored for fecal indicator bacteria (fecal coliforms, Escherichia coli, enterococci), but shortcomings of the analytical test (lengthy assay) have resulted in a re-focusing of scientific efforts to improve public health protection. Research has led to the discovery of widespread populations of fecal indicator bacteria present in natural habitats such as soils, beach sand, and stranded algae. Microbial source tracking has been used to identify the source of these bacteria and subsequently assess their impact on human health. As a result of many findings, attempts have been made to improve monitoring efficiency and efficacy with the use of empirical predictive models and molecular rapid tests. All along, beach managers have actively incorporated new findings into their monitoring programs. With the abundance of research conducted and information gained over the last 25 years, “Beach Science” has emerged, and the Great Lakes have been a focal point for much of the ground-breaking work. Here, we review the accumulated research on microbiological water quality of Great Lakes beaches and provide a historic context to the collaborative efforts that have advanced this emerging science.

  15. Reconstruction of an interrupted primary beach plain succession using a Geographical Information System

    NARCIS (Netherlands)

    Veen, A. van der; Grootjans, A.P.; de Jong, J.; Rozema, J.

    1997-01-01

    This study reports on a primary succession on a beach plain on the Dutch Wadden island of Schiermonnikoog. Vegetation succession started in 1959 when a sand dike was constructed to prevent structural erosion of the area by storm floods. Since then the sandy beach behind the dike has been protected f

  16. Modes of embayed beach dynamics: analysis reveals emergent timescales

    Science.gov (United States)

    Murray, K. T.; Murray, A.; Limber, P. W.; Ells, K. D.

    2013-12-01

    Embayed beaches, or beaches positioned between rocky headlands, exhibit morphologic changes over many length and time scales. Beach sediment is transported as a result of the day-to-day wave forcing, causing patterns of erosion and accretion. We use the Rocky Coastline Evolution Model (RCEM) to investigate how patterns of shoreline change depend on wave climate (the distribution of wave-approach angles) and beach characteristics. Measuring changes in beach width through time allows us to track the evolution of the shape of the beach and the movement of sand within it. By using Principle Component Analysis (PCA), these changes can be categorized into modes, where the first few modes explain the majority of the variation in the time series. We analyze these modes and how they vary as a function of wave climate and headland/bay aspect ratio. In the purposefully simple RCEM, sediment transport is wave-driven and affected by wave shadowing behind the headlands. The rock elements in our model experiments (including the headlands) are fixed and unerodable so that this analysis can focus purely on sand dynamics between the headlands, without a sand contribution from the headlands or cliffs behind the beach. The wave climate is characterized by dictating the percentage of offshore waves arriving from the left and the percentage of waves arriving from high angles (very oblique to the coastline orientation). A high-angle dominated wave climate tends to amplify coastline perturbations, whereas a lower-angle wave climate is diffusive. By changing the headland/bay aspect ratio and wave climate, we can perform PCA analysis of generalized embayed beaches with differing anatomy and wave climate forcings. Previous work using PCA analysis of embayed beaches focused on specific locations and shorter timescales (beach dynamics over longer timescales. The first two PCA modes, which explain a majority of the beach width time series variation (typically >70%), are a 'breathing' mode and a

  17. Beach nourishment in the USA, the history, the impacts, and the future

    Science.gov (United States)

    Young, Robert; Coburn, Andrew

    2017-04-01

    Currently, the primary tool being used at the local, state, and federal level in the USA to adapt to rising sea level, and to reduce potential storm damage is the addition of sand to the coastal system in the form of engineered beaches and dunes (commonly referred to as beach nourishment or beach replenishment). At the Program for the Study of Developed Shorelines, we have built a comprehensive database of all beach dredge and fill projects in the USA. The database tracks a history of beach projects that date back to 1923 with continual updates as new projects are implemented today. The projects in the database represent the movement of over 950 million cubic meters of sand covering over 3700 km of shoreline. This massive program of shoreline stabilization is being carried out with little long-term vision or planning, and no consideration for the cumulative environmental impacts of mining and placing so much sand. It is no exaggeration to say that a significant portion of the US East and Gulf Coasts are now completely artificial constructs, with engineering replacing natural processes. Along many shorelines, beach nourishment has become unsustainable as sand sources diminish. In addition, the cost of moving the sand has increased dramatically as communities scramble to build beaches and dunes. This program is not sustainable into the future, but there has been no widespread recognition of this reality, nor any move towards sensible retreat from the coast.

  18. Sand transport processes in the surf and swash zones

    NARCIS (Netherlands)

    Zanden, van der Joep

    2016-01-01

    Long-term predictions of beach morphology using numerical models contribute to cost-effective coastal protection strategies. The physics of sand transport in the wave breaking region and the swash zone are not fully understood, leading to poor predictive capability of existing sand transport models

  19. The role of beach morphodynamic state on infragravity swash on beaches: field observations.

    Science.gov (United States)

    Gomes da Silva, Paula; González, Mauricio; Medina, Raul

    2017-04-01

    The runup generated by waves can be defined as the maximum height above sea water level on the coastline and is an important criterion for costal structures/nourishment design and erosion/flooding risk analysis. Given the complexity of nonlinear processes involved in the runup generation, its prediction is commonly made by means of empirical formulations that relate wave and beach parameters. The most accepted parametrization presented till the moment was proposed by Stockdon et al. (2006), in which the runup exceeded by 2 percent of the waves (R2) is described in terms of setup (η - the steady superelevation of the mean water level caused by breaking waves) and incident and infragravity swash (Sinc and Sig- time-varying fluctuations around the setup caused by non-breaking waves). Such formulation has been widely accepted and its efficiency was appraised in many works. Nevertheless, although empirical parametrization of infragravity swash using incident wave's parameters shows reasonable skill, the correlation can still present considerable scatter. The amount of infragravity energy on swash is directly related to the morphodynamic beach state, in a way that beach profiles classified as reflective (low wave energy, coarse sediment and higher beach slope) tend to show lower Sig values than dissipative ones (high wave energy, fine sediment and lower beach slope). However, since Stockdon's formula for predicting infragravity swash consider only wave parameters, its use implies that beaches receiving the same wave energy but with different grain size and beach slope would present the same Sig values. This work assumed the hypothesis that the scatter verified on the predictions of the infragravity swash is mainly related to the lack of information about the beach state in Stockdon formula. Based on that, a field campaign was designed and carried out in Somo-El Puntal beach, north Spain, with the aim of generating data to be analyzed in terms of infragravity swash. An

  20. LEARNING ABOUT THE OCEANS FROM SAND

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    As a young geophysicist in the 1980s, Rob Holman attended a conference in San Francisco that included a field trip to a beach. Dr Holman, who grew up inland, stared at the ocean, assessing the strengths of the waves. But when he looked around, everyone else was studying the sand.

  1. Preliminary risk assessment of the wet landscape option for reclamation of oil sands mine tailings: bioassays with mature fine tailings pore water.

    Science.gov (United States)

    Madill, R E; Orzechowski, M T; Chen, G; Brownlee, B G; Bunce, N J

    2001-06-01

    Chemical and biological assays have been carried out on the "pore water" that results from the settling of the tailings that accompany bitumen recovery from the Athabasca oil sands. Examination of the nonacidic extracts of pore water by gas chromatography-mass spectroscopy allowed the identification of numerous two- to three-ring polycyclic aromatic compounds (PACs), to a total concentration of 2.6 micrograms/L of pore water. The PACs were biodegraded by microflora naturally present in the pore water. Acute toxicity was associated principally with the acidic fraction (naphthenic acids) of pore water extracts according to the Microtox assay; other work has shown that acute toxicity dissipates fairly rapidly. Both individual PACs and concentrated pore water extracts showed minimal levels of binding to the rat Ah receptor and induced minimal ethoxyresorufin-O-deethylase activity in primary rat hepatocytes, showing an insignificant risk of inducing monooxygenase activity. Taken together with previous work showing negligible mutagenic activity of these extracts, we conclude that it should be possible to develop tailing slurries into biologically productive artificial lakes.

  2. 海滩湿润沙面起动摩阻风速的风洞实验%Wind Tunnel Experiment of the Threshold Friction Wind Velocity on Wet Beach Sand Surface

    Institute of Scientific and Technical Information of China (English)

    韩庆杰; 屈建军; 张克存; 俎瑞平; 廖空太; 牛清河

    2011-01-01

    Wind erosion is one kind of important geomorphology processes and geological disasters,which has significant impacts on dune growth and desertification,and causes damages to architecture on sea coasts.The moisture of sand surface layer greatly affects the threshold wind velocity and sand stability,thus,it is also one of the important influence factors on wind erosion.In this study,we investigated the influence of surface moisture content at 1-mm depth on sand erosion in tropical humid coast of southern China,and established a new predicting model.The modeling results indicated that the threshold friction velocity increased linearly with increasing of ln100M(M is gravimetric moisture content) in condition of given sand diameters.Evaluation was given to seven popular models for predicting the threshold friction velocity on moisture sediments,and found that there were significant differences among their predicted results.At a surface sand moisture content of 0.0124(M1.5),the predicted threshold friction velocity predicted by the seven models were 34% to 195% larger than the observed threshold friction velocity on dry sands;at a surface sand moisture content of lower than 0.0062(0.5 M1.5),the predicted values by models of Chepil and Saleh well matched the experimental data;but when surface sand moisture content of more than 0.0062(0.5 M1.5),the data simulated by the Belly's empirical model were seem same as the experimental data.%风蚀是一种重要的地貌过程和地质灾害,它影响海岸沙丘的增长,加速土地沙漠化并危害沿岸建筑。沙面湿度强烈影响沙粒的临界起动风速和沙面稳定性,因此,也是影响风蚀过程的一个重要因子。本项风洞实验使用华南热带湿润海岸的海滩沙,研究了表面湿度(1mm深)对海滩沙风蚀起动的影响,建立了一个新的预测热带湿润海滩湿沙起动摩阻风速的模型,该模型指明给定粒径下,湿沙的起动摩阻风速随ln100 M

  3. Developing a Sand Management Plan for Galveston Island

    Science.gov (United States)

    2015-10-16

    US Army Corps of Engineers BUILDING STRONG® Developing a Sand Management Plan for Galveston Island Ashley E. Frey, P. E. Research Civil...GenCade Alternatives • Sand Management Alternatives and Plan • Beach Nourishment Project 2 Innovative solutions for a safer, better world...BUILDING STRONG® Problem Statement/Approach Recommend a long-term plan of actions to better manage sands on Galveston Island Initial Tasks

  4. 75 FR 3915 - Environmental Documents Prepared in Support of Sand and Gravel Activities on the Outer...

    Science.gov (United States)

    2010-01-25

    ... Minerals Management Service Environmental Documents Prepared in Support of Sand and Gravel Activities on... for three sand and gravel activities proposed on the Outer Continental Shelf (OCS) and described in... noncompetitive basis, the rights to OCS sand, gravel, or shell resources for shore protection, beach or...

  5. Miramar (Goa) Beach Management Project: An Oceanographic Evaluation

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.; Ingole, B.S.

    and permanently eliminate faunal diversity. Human actions are responsible for the degradation of vegetation resulting in exposed dunes at Miramar. When wind speed attains around 20 km/h, continuous eolian transport and loss of beach sand onto roads is one major...

  6. Substituição de areia de quartzo por finos de gnaisse em massa cerâmica para telhas: teste industrial Replacing quartz sand for gnaisse fines waste into roofing tile body: industrial test

    Directory of Open Access Journals (Sweden)

    C. M. F. Vieira

    2008-12-01

    Full Text Available Foi avaliado o efeito da substituição de areia por um resíduo de beneficiamento de rocha ornamental, finos de gnaisse, em uma massa de cerâmica vermelha utilizada para fabricação de telhas. Foram preparadas telhas prensadas, do tipo "portuguesa", para queima a 900 ºC em forno industrial. As seguintes propriedades foram determinadas: retração linear, absorção de água e carga de ruptura na flexão. Além disso, avaliaram-se as características das matérias-primas e a plasticidade das composições por meio dos limites de Atterberg. Os resultados indicaram que a utilização de finos de gnaisse em substituição à areia possibilitou uma melhoria na trabalhabilidade/plasticidade da massa cerâmica e acarretou uma pequena redução na absorção de água das telhas. A resistência mecânica não se alterou, dentro da precisão estatística das medidas.The effect of replacing sand for gnaisse sawing waste into a red ceramic body used for roofing tile fabrication was evaluated. Pressed roofing tiles, "portuguese" style, were prepared before firing at 900 ºC in an industrial furnace. The following properties were evaluated: linear shrinkage, water absorption and load rupture strength. The plasticity of the elaborated compositions was determined by the Atterberg limits. The results show that the use of gnaisse fines replacing the sand, improved the workability of the ceramic body and promoted a slight decrease on the water absorption of the roofing tiles. The mechanical strength was not changed within the statistical error.

  7. Tidal flow separation at protruding beach nourishments

    Science.gov (United States)

    Radermacher, Max; de Schipper, Matthieu A.; Swinkels, Cilia; MacMahan, Jamie H.; Reniers, Ad J. H. M.

    2017-01-01

    In recent years, the application of large-scale beach nourishments has been discussed, with the Sand Motor in the Netherlands as the first real-world example. Such protruding beach nourishments have an impact on tidal currents, potentially leading to tidal flow separation and the generation of tidal eddies of length scales larger than the nourishment itself. The present study examines the characteristics of the tidal flow field around protruding beach nourishments under varying nourishment geometry and tidal conditions, based on extensive field observations and numerical flow simulations. Observations of the flow field around the Sand Motor, obtained with a ship-mounted current profiler and a set of fixed current profilers, show that a tidal eddy develops along the northern edge of the mega-nourishment every flood period. The eddy is generated around peak tidal flow and gradually gains size and strength, growing much larger than the cross-shore dimension of the coastline perturbation. Based on a 3 week measurement period, it is shown that the intensity of the eddy modulates with the spring-neap tidal cycle. Depth-averaged tidal currents around coastline perturbations are simulated and compared to the field observations. The occurrence and behavior of tidal eddies is derived for a large set of simulations with varying nourishment size and shape. Results show that several different types of behavior exist, characterized by different combinations of the nourishment aspect ratio, the size of the nourishment relative to the tidal excursion length, and the influence of bed friction.

  8. Erosion Negril Beach

    NARCIS (Netherlands)

    Ten Ham, D.; Henrotte, J.; Kraaijeveld, R.; Milosevic, M.; Smit, P.

    2006-01-01

    The ongoing erosion of the Negril Beach has become worse the past decade. In most places along the coast line, the beach will be gone in approximately 10 years. This will result in a major decrease of incomes that are made by the local tourist sector. To prevent the erosion this study has been perfo

  9. Measurement of fine particulate matter water-soluble inorganic species and precursor gases in the Alberta Oil Sands Region using an improved semicontinuous monitor.

    Science.gov (United States)

    Hsu, Yu-Mei; Clair, Thomas A

    2015-04-01

    The ambient ion monitor-ion chromatography (AIM-IC) system, which provides hourly measurements of the main chemical components of PM2.5 (particulate matter with an aerodynamic diameterPM2.5 sampler. The correlation coefficients of SO4(2-) concentrations between the AIM-IC and ADSS and between the AIM-IC and the Partisol PM2.5 sampler were 0.98 and 0.95, respectively. The comparisons also showed no statistically significant difference between the measurement sets, suggesting that the AIM-IC measurements of the PM2.5 chemical composition are comparable to the ADSS and Partisol PM2.5 methods. NH3 concentration in the summer (mean±standard deviation, 1.9±0.7 µg m(-3)) was higher than in the winter (1.3±0.9 µg m(-3)). HNO3 and NO3- concentrations were generally low in the AOSR, and especially in the winter months. NH4+ (0.94±0.96 µg m(-3)) and SO4(2-) (0.58±0.93 µg m(-3)) were the major ionic species of PM2.5. Direct SO2 emissions from oil sands processing operations influenced ambient particulate NH4+ and SO4(2-) values, with hourly concentrations of NH4+ and SO4(2-) measured downwind (~30 km away from the stack) at 10 and 28 µg m(-3). During the regional forest fire event in 2011, high concentrations of NO3-, NH4+, HNO3, NH3, and PM2.5 were observed and the corresponding maximum hourly concentrations were 31, 15, 9.6, 89, and >450 (the upper limit of PM2.5 measurement) µg m(-3), suggesting the formation of NH4NO3. The AOSR in Canada is one of the most scrutinized industrial regions in the developed world due to the extent of oil extraction activities. Because of this, it is important to accurately assess the effect of these operations on regional air quality. In this study, we compare a new analytical approach, AIM-IC, with more standard analytical approaches to understand how local anthropogenic and nonanthropogenic sources (e.g., forest fires) impact regional air quality. With this approach, we also better characterize PM2.5 composition and its precursor

  10. Louisiana's statewide beach cleanup

    Science.gov (United States)

    Lindstedt, Dianne M.; Holmes, Joseph C.

    1989-01-01

    Litter along Lousiana's beaches has become a well-recognized problem. In September 1987, Louisiana's first statewide beach cleanup attracted about 3300 volunteers who filled 16,000 bags with trash collected along 15 beaches. An estimated 800,173 items were gathered. Forty percent of the items were made of plastic and 11% were of polystyrene. Of all the litter collected, 37% was beverage-related. Litter from the oil and gas, commercial fishing, and maritime shipping industries was found, as well as that left by recreational users. Although beach cleanups temporarily rid Louisiana beaches of litter, the real value of the effort is in public participation and education. Civic groups, school children, and individuals have benefited by increasing their awareness of the problems of trash disposal.

  11. 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.

  12. 番禺30-1气田水平井精细防砂研究与实践%Research and practice of fine sand control for horizontal well in Panyu 30-1 offshore gas field

    Institute of Scientific and Technical Information of China (English)

    熊友明; 张伟国; 罗俊丰; 刘理明; 熊泳杰; 朱玥

    2011-01-01

    番禺30-1气田是以水平井开发为主的海上深水气田,生产时地层出砂,必须采用先期防砂完井才能投产.海上深水气田开发的高成本决定了其防砂措施必须可靠,因此需要确定该气田水平井采用的高级优质筛管的防砂层结构和综合挡砂精度.采用实际的地层岩心,通过室内出砂模拟实验确定了高级优质筛管防砂的合理挡砂精度,获得了不同于常规的防砂设计准则.生产实践表明,采用出砂模拟实验确定的挡砂精度比直接采用防砂准则设计的挡砂精度更加可靠,防砂后产量高,防砂效果好,为此类气田进行精细防砂设计提供了新的思路.%The Panyu 30-1 gas field in deep water is mainly developed by horizontal wells and its formation is easy to sand, so it is necessary to adopt pre-sand control when put into production. The high investment cost for deep offshore gas fields' development has determined that sand control must be reliable and secure, and the research about the advanced high quality screen structure and block sand precision is necessary. By using the actual formation core, this paper determined the suitable precision of sand blocking with advanced high quality screen through experiments, and got the new sand controlling design criteria which is different from the conventional one. The actual production figures show the gas wells had high yield and good sand control effect after sand controlling, which provides a new fine-sand design idea for the sand control in such kinds of gas fields. At the same time, specific research and practice indicate that the block sand precision determined by the sanding simulation experiment is more reliable than those by sanding design criteria.

  13. Physical Characterizations of Sands and Their Influence in Fall Velocity

    Directory of Open Access Journals (Sweden)

    R. M. Gabriel

    2008-01-01

    Full Text Available Cancun beach is one of the most important tourist resorts on the Mexican coast, and is of prime importance to the local and national economies. As a result of the intense use of the beach and the unavailability of sand reserves, the extreme weather events that occur in the region (hurricanes have permanently damaged the beach. Over the last two decades several strong hurricanes severely weakened the system, but hurricane Wilma, October 2005, caused devastating erosion to the beach. After Wilma, an emergency nourishment project was implemented pumping a volume of 2.7 million m3 of sand onto the beach. Clearly, the sand used for the nourishment has a different shape factor, diameter distribution and density property compared to the native sand. The main goal of this paper is to characterize and compare the fall velocities of sand samples taken in and around Cancun. The settling velocities obtained for several samples were compared with the empirical formulations proposed by various authors. The influence of several parameters measured in the laboratory is discussed and a new formulation is presented.

  14. The Geomorphic System and the Effects of Human Interference at Gold Coast Beach in Tainan, Taiwan

    Science.gov (United States)

    Lin, Tsung-Yi

    2017-04-01

    The Gold Coast beach in Tainan, Taiwan, located between Anping harbor and Ur-Jen river mouth, is the subject of this study, which characterizes the beach's geomorphic system through the analysis of information such as sediment grain size, mineral composition, and periodic measurements of morphological changes of the beach. Based upon such characterizations, further analysis is conducted on the effects that human activities of the last 15 years have upon the geomorphic changes within the Gold Coast beach. The study shows that the median grain size of the Gold Coast beach's sediment is medium sand. The mineral composition includes mainly slate fragments and quartz grains, with small amounts of feldspar, sandstone and shell fragments. Based on a comprehensive study of the longshore distribution of beach sediment size and mineral composition of southwestern coast of Taiwan, as well as, the long-term, monitored data of waves, tides, and currents in this region, we conclude that the main process responsible for the sand accumulation at Gold Coast beach is the prevailing longshore sand transport from south to north. The southern breakwater of Anping harbor plays a role in intercepting the longshore transport sand and helps form the beach. Since the Ur-Jen river flows through a mudstone region, the suspended sediment plume during the flood season does not provide much sediment source to the sandy beach. A monthly beach profile survey project conducted between the years 1999 to 2000 revealed that the beach elevation and width had experienced an obvious seasonal change. The beach widened during the winter, but narrowed in the summer due to typhoon wave erosion. When the subaerial beach was eroded, a submerged longshore bar that was oriented almost parallel to the shoreline had formed at a distance about 400-600 meter away. With this observation, we can conclude that beach morphology is also influenced by various seasonal wave actions that affect onshore and offshore sand

  15. Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

    Science.gov (United States)

    Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

    2016-06-01

    The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

  16. Holocene cemented beach deposits in Belize

    Science.gov (United States)

    Gischler, Eberhard; Lomando, Anthony J.

    1997-06-01

    Two types of cemented beach deposits occur on reef islands off the coast of Belize. These are (1) intertidal beachrock that is dominantly cemented by marine aragonite and high-magnesium-calcite cements, and (2) supratidal cayrock that is cemented mainly by vadose low-magnesium-calcite cements. Besides differences in position relative to present sea level and resulting early diagenesic features, beachrock and cayrock can be distinguished on the basis of differences in composition, texture, geographical position, and age. Whereas the composition of beachrock is similar to that of the adjacent marginal reef sediments, cayrock is enriched in benthic foraminifera. Intertidal beachrock is moderately to well sorted and well cemented, while supratidal cayrock is very well sorted, poorly cemented and friable. Beachrock occurs preferentially on windward beaches of sand-shingle Gays on the middle and southern barrier reefs and on the isolated platforms Glovers and Lighthouse Reefs. Cayrock only occurs on larger mangrove-sand Gays of the isolated platforms Turneffe Islands, Lighthouse Reef, and the northern barrier reef. 14C-dating of ten whole-rock and mollusk shell samples produced calibrated dates between AD 345 and AD 1435 for beachrock and between BC 1085 and AD 1190 for cayrock. The large-scale distribution of beachrock in Belize supports the contention that physical processes such as water agitation rather than biological processes control beachrock formation and distribution. Only on windward sides of cays that are close to the reef crest, where large amounts of seawater flush the beaches, considerable amounts of cements can be precipitated to produce beachrock. Cayrock forms due to cementation in the vadose zone and is only preserved on larger, stable mangrove-sand cays.

  17. Short- and medium-term response to storms on three Mediterranean coarse-grained beaches

    Science.gov (United States)

    Grottoli, Edoardo; Bertoni, Duccio; Ciavola, Paolo

    2017-10-01

    The storm response of three Italian coarse-grained beaches was investigated to better understand the morphodynamics of coarse-clastic beaches in a microtidal context. Two of the studied sites are located on the eastern side of the country (Portonovo and Sirolo) and the third one (Marina di Pisa) is on the western side. Portonovo and Sirolo are mixed sand and gravel beaches where the storms approach from two main directions, SE and NE. Marina di Pisa is a coarse-grained, gravel-dominated beach, exposed to storms driven by SW winds. Gravel nourishments were undertaken in recent years on the three sites. Beach topography was monitored measuring the same network of cross sections at a monthly (i.e. short-term) to seasonal frequency (i.e. medium-term). Geomorphic changes were examined before and after storm occurrences by means of profile analyses and shoreline position evaluations. The beach orientation and the influence of hard structures are the main factors controlling the transport and accumulation of significant amount of sediments and the consequent high variability of beach morphology over the medium-term. For Marina di Pisa, storms tend to accumulate material towards the upper part of the beach with no shoreline rotation and no chance to recover the initial configuration. Sirolo and Portonovo showed a similar behaviour that is more typical of pocket beaches. Both beaches show shoreline rotation after storms in a clockwise or counter-clockwise direction according to the incoming wave direction. The wider and longer beach at Sirolo allows the accumulation of a thin layer of sediment during storms, rather than at Portonovo where, given its longshore and landward boundaries, the beach material tends to accumulate in greater thickness. After storms, Sirolo and especially Portonovo can quickly recover the initial beach configuration, as soon as another storm of comparable energy approaches from the opposite direction of the previous one. Large morphological

  18. Bores and Swash on Natural Beaches.

    Science.gov (United States)

    1982-07-01

    MODERATE ENERGY -Im Punk ~ -- -- -- ... .. !60~~ 50 o f5 TsCS) --- -midsurf zone -----U - midsurf zone -U - swosh FIGURE 5 .2 burf zone and awash spectra from...pp 401-410. 2Bascom, N.., 1951, 8Th* relationship between sand size and beach face slope, Trans. Am. GOophys. Union, Vol 32 () pp 866-874. Bradshaw...dry bed*, ASCS. Jour. Hyd. Div., HY2, pp 187-216. 100 Friedman, G.F., 1967, nDynamic processes and statistical measures compared for size frequency

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

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, W.F.; Demirpolat, S.

    1988-09-01

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

  20. National List of Beaches

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPA has published a list of coastal recreation waters adjacent to beaches (or similar points of access) used by the public in the U.S. The list, required by the...

  1. Beach Ball Coronagraph Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The “Beach Ball” Coronagraph will be the first steps to simplify and revolutionize the next generation solar coronagraph design.  The solar corona...

  2. 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.

  3. Does beach nourishment have long-term effects on intertidal macroinvertebrate species abundance?

    Science.gov (United States)

    Leewis, Lies; van Bodegom, Peter M.; Rozema, Jelte; Janssen, Gerard M.

    2012-11-01

    Coastal squeeze is the largest threat for sandy coastal areas. To mitigate seaward threats, erosion and sea level rise, sand nourishment is commonly applied. However, its long-term consequences for macroinvertebrate fauna, critical to most ecosystem services of sandy coasts, are still unknown. Seventeen sandy beaches - nourished and controls - were sampled along a chronosequence to investigate the abundance of four dominant macrofauna species and their relations with nourishment year and relevant coastal environmental variables. Dean's parameter and latitude significantly explained the abundance of the spionid polychaete Scolelepis squamata, Beach Index (BI), sand skewness, beach slope and latitude explained the abundance of the amphipod Haustorius arenarius and Relative Tide Range (RTR), recreation and sand sorting explained the abundance of Bathyporeia sarsi. For Eurydice pulchra, no environmental variable explained its abundance. For H. arenarius, E. pulchra and B. sarsi, there was no relation with nourishment year, indicating that recovery took place within a year after nourishment. Scolelepis squamata initially profited from the nourishment with "over-recolonisation". This confirms its role as an opportunistic species, thereby altering the initial community structure on a beach after nourishment. We conclude that the responses of the four dominant invertebrates studied in the years following beach nourishment are species specific. This shows the importance of knowing the autecology of the sandy beach macroinvertebrate fauna in order to be able to mitigate the effects of beach nourishment and other environmental impacts.

  4. Occurrence of soft sediment deformation at Dive Agar beach, west coast of India: possible record of the Indian Ocean tsunami (2004)

    Digital Repository Service at National Institute of Oceanography (India)

    Meshram, D.C.; Sangode, S.J.; Gujar, A.R.; Ambre, N.V.; Dhongle, D.; Porate, S.

    by approx.30-cm-thick intermixed beach sand and terrigenous sand (layer B1) followed by complex load structures and convolutions (8–15 cm) within a coarse sandy layer (B2). The layer B2 is scoured by terrigenous sand (layer C1) which is capped with a silty...

  5. Modeling the Economics of Beach Nourishment Decisions in Response to Coastal Erosion

    Science.gov (United States)

    Ware, M.; Ashton, A. D.; Hoagland, P.; Jin, D.; Kite-Powell, H.; Lorenzo-Trueba, J.

    2012-12-01

    Beaches are constantly moving and changing. The dynamic transformations of beaches are mostly the result of the erosion of sand, which can occur through movements alongshore caused by waves, movements off-shore due to storms, or submersion due to sea-level rise. Predicted climate change impacts include potential changes in storminess and accelerated sea-level rise, which will lead to increased coastal erosion. At the same time, the number of people residing in coastal communities is increasing. The risks from eroding beaches (increased coastal flooding, damage to infrastructure, and displaced residents) are therefore increasing in number and scale; and coastal residents are taking actions to protect their homes. One such action is beach nourishment, where sand is added to a resident's property in order to widen the beach. We have developed an economic model of beach nourishment decision-making to investigate the relationship between the optimal volume and timing of beach nourishment and factors such as property value, erosion rate, and initial beach width. In this model, waterfront property owners nourish a beach when the losses in net rental income exceed the costs incurred from nourishing the beach. (Rental income is a function of property value, which in turn depends upon the width of the beach.) It is assumed that erosion and sea-level rise are related. We examine different nourishment scenarios, including one-time nourishment in the first year; constant annual nourishment; and a myopic decision process in which the homeowner nourishes the beach if property losses from erosion over the next five years are expected to exceed the cost of nourishment. One-time nourishment delays property flooding for both constant and accelerating sea level rise; however, this delay is more substantial under constant sea level rise. With continual nourishment, the beach can be maintained under constant sea-level rise, provided that the erosion rate is comparable to the additional

  6. Factors Influencing the Accumulation and Subsurface Transport of Fecal Indicator Bacteria near the Shoreline at Freshwater Beaches

    Science.gov (United States)

    Wu, M. Z.; O'Carroll, D. M.; Vogel, L. J.; Robinson, C. E.

    2015-12-01

    Beach sand near the shoreline acts as a reservoir for fecal contaminants with fecal indicator bacteria (FIB) often orders of magnitude higher than in adjacent surface waters. This reservoir poses a human health risk and can also act as an important non-point contamination source for surface waters. Beach water quality advisories or closures can be issued when FIB (Escherichia coli (E. coli), enterococci (ENT)) concentrations are elevated in the surface water. The factors controlling the transport and accumulation of FIB in the foreshore sand are not well understood, though this is required to manage and mitigate this source. Multiple sources may contribute to the accumulation of FIB in sand, with recent studies suggesting that the continuous influx of surface water across the sediment-water interface may be a dominant source at many beaches.The study objective was to develop understanding of the physical processes controlling the accumulation and transport of FIB in beach sand. Field measurements were combined with numerical modelling to evaluate the role of low-energy lapping waves in delivering FIB to the saturated foreshore sand at freshwater beaches. E. coli and ENT were measured at two beaches in Ontario, Canada at depths of up to 1 and 2 m, respectively, below the water table. A numerical model simulating wave-induced groundwater recirculations coupled with microbial transport (using colloid filtration theory) showed that the different FIB distributions measured at the two beaches was due mainly to the different beach slope and terrestrial groundwater flow. The model was applied to assess the impact of beach, wave and bacterial parameters on FIB accumulation. The infiltration zone width, average infiltration velocity and infiltration rate were shown to ultimately control the amount and spatial distribution of FIB in the sand. The study findings are important in understanding factors controlling the transport of FIB at the sediment-water interface of

  7. 76 FR 19122 - Record of Decision (ROD) for Authorizing the Use of Outer Continental Shelf (OCS) Sand Resources...

    Science.gov (United States)

    2011-04-06

    ... the Use of Outer Continental Shelf (OCS) Sand Resources in National Aeronautics and Space... Availability (NOA) of the Record of Decision. SUMMARY: BOEMRE has issued a ROD to authorize the use of OCS sand... for the purpose of making sand available from a shoal on the OCS for placement on the beach in...

  8. 77 FR 24980 - Record of Decision for Authorizing the Use of Outer Continental Shelf (OCS) Sand Resources in the...

    Science.gov (United States)

    2012-04-26

    ... (OCS) Sand Resources in the Martin County, Florida Hurricane Storm Damage Reduction Project AGENCY... Decision. SUMMARY: BOEM has issued a Record of Decision (ROD) to authorize the use of OCS sand resources by... agreement for the purpose of making sand available from a shoal on the OCS for placement on the beach...

  9. The sedimentary source, planform stability and shore normal morphological change of the Xichong beach on the southern coast of the Dapeng Peninsula of Shenzhen, Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Song; WANG Wei; HUANG Rihui; XU Liubing

    2015-01-01

    The coast of the Dapeng Peninsula has been honored as one of “the eight most beautiful coasts in China”. The most precious tourism resource for the peninsula is headland bay beaches, among which the beach at Xichong on the southern coast of the peninsula is the longest and the most important one. The information of the stability, sedimentary source and shape change of the beach is very important for maintaining the beach in terms of sustainable development of the peninsula. Heavy minerals in the sand of the beach and the inland stream at Xichong are compared with those of a nearby beach on the same coast to determine the beach sand source; with help of a computer software, MEPBAY, the equilibrium planforms of the beaches on the peninsula are compared with those of an island without rivers to evaluate the stream's effects on the beach stability; cross shore profiles along the Xichong beach are also surveyed in different seasons of a year to assess the annual shore normal beach changes affected by the stream input, and the relation between the equilibrium planform state and cross shore changes of the beach. It is shown that (1) stream is the main sedimentary source of the beach and the weathering materials of the rocky headlands on both sides of the bay transported by waves are the second source for the beach but it is limited, sand from an inner shelf is not the sedimentary source for the beach at present and was not even during the Holocene transgression; (2) the Xichong beach cannot reach static equilibrium around the entire bay shoreline, the segment of the shore-line where a stream outlet is located is in dynamic equilibrium, and the unstable section occurs in the wave shadow region in the lee of an offshore island; (3) no matter whether the section of the beach shoreline at Xichong is in an equilibrium state or not, it is eroded in the typhoon season and recovered after the season, the maximum change in erosion and accretion occurs in the unstable segment

  10. Coastal processes influencing water quality at Great Lakes beaches

    Science.gov (United States)

    ,

    2013-01-01

    In a series of studies along the Great Lakes, U.S. Geological Survey scientists are examining the physical processes that influence concentrations of fecal indicator bacteria and related pathogens at recreational beaches. These studies aim to estimate human health risk, improve management strategies, and understand the fate and transport of microbes in the nearshore area. It was determined that embayed beaches act as traps, accumulating Escherichia coli (E. coli) and other bacteria in the basin and even in beach sand. Further, shear stress and wave run-up could resuspend accumulated bacteria, leading to water-contamination events. These findings are being used to target beach design and circulation projects. In previous research, it was determined that E. coli followed a diurnal pattern, with concentrations decreasing throughout the day, largely owing to solar inactivation, but rebounding overnight. Studies at a Chicago beach identified the impact of wave-induced mass transport on this phenomenon, a finding that will extend our understanding of bacterial fate in the natural environment. In another series of studies, scientists examined the impact of river outfalls on bacteria concentrations, using mechanistic and empirical modeling. Through these studies, the models can indicate range and extent of impact, given E. coli concentration in the source water. These findings have been extended to extended lengths of coastlines and have been applied in beach management using empirical predictive modeling. Together, these studies are helping scientists identify and eliminate threats to human and coastal health.

  11. Population structure and reproductive biology of Metamysidopsis neritica (Crustacea: Mysidacea in a sand beach in south Brazil Estrutura populacional e biologia reprodutiva de Metamysidopsis neritica (Crustacea: Mysidacea em uma praia arenosa do sul do Brasil

    Directory of Open Access Journals (Sweden)

    Patrícia Calil

    2008-09-01

    Full Text Available Mysidacea are common sublittoral crustaceans that inhabit all coasts in the world. In this study, the population characteristics and the reproductive biology of Metamysidopsis neritica Bond-Buckup & Tavares, 1992 were studied in the surf zone of a south Brazilian beach (Atami. Mysids were sampled at monthly intervals from August, 1999 to July, 2000 (total of 29,490 individuals. Individuals were classified into six population categories. The highest abundance occurred in May (8,665 and August (6,415, and lowest in September (336 and December (368. Three main generations were identified, namely the summer, fall and winter generations. The winter generation was the longest (four to five months. The fall generation lasted four months, and the summer one extended from three to four months. Ovigerous females occurred throughout the year, with a greater proportion in July. The number of eggs or larvae varied from one to 16. Weak associations were found between female length and egg number, egg volume, and the number of larvae with and without eyes. Egg volume increased during the coldest season, whereas the smallest values were recorded during summer. These results suggest a possible direct relationship between egg volume and generation longevity.Misidáceos são crustáceos comuns no sublitoral de todo o mundo. Neste estudo as características populacionais e a biologia reprodutiva de Metamysidopsis neritica Bond-Buckup & Tavares, 1992 foram estudadas na zona de arrebetação de uma praia no sul brasileiro (Atami. Os misidáceoa foram coletados mensalmente no período de agosto/1999 a julho/2000 (total de 29490 exemplares. Os indivíduos foram classificados em seis categorias populacionais. A maior abundância ocorreu em maio (8665 e em agosto (6415, e a menor, em setembro (336 e dezembro (368. Foram identificadas três principais gerações, nomeadas de geração do verão, do outono e do inverno. A com maior longevidade foi a do inverno (quatro a

  12. Beach morphodynamics and types of foredune erosion generated by storms along the Emilia-Romagna coastline, Italy

    Science.gov (United States)

    Armaroli, Clara; Grottoli, Edoardo; Harley, Mitchell D.; Ciavola, Paolo

    2013-10-01

    The objectives of this study are to examine the response of a dune and beach system on the Adriatic coastline in northern Italy to the arrival of storms, compare it with seasonal (months) and medium-term (3-year) morphodynamic change, and evaluate results predicted by the numerical model XBeach. The studied coastline stretches 4 km from the Bevano River mouth to the north of the site to the township of Lido di Classe to the south, where the beach is protected by coastal structures. Fieldwork consisted of topographic profile surveys using RTK-DGPS technology (7 times over an approx. 3-year period). 103 samples of surface sediment were collected along 20 of the cross-shore profiles at 6 distinct cross-shore positions, selected on the basis of morphological beach characteristics. Data analyses of dune and beach slopes enabled the study area to be divided into 6 separate morphological zones using the spatial (longshore and cross-shore) variation of morphologies located on the backshore and intertidal beach observed in a preliminary survey of the area. Other criteria were a spatial consistency in beach slopes and/or presence/absence of intertidal morphologies identified in the aerial photographs and Lidar data. The swash zone slope did not show any significant variability for the entire area. A weak seasonal trend in the variability of the mean foredune slope was observed, with steeper slopes typically during winter and flatter slopes during summer. Analysis of grain size revealed that the beach sediment is well-sorted fine sand tending to medium, with a decreasing trend in size from the Bevano River mouth southwards towards Lido di Classe. According to the Masselink and Short (1993) classification, the natural part of the study site has an Intermediate Barred Beach (IBB) and following the Short (1999) classification, results in a modally LBT (longshore bar-trough) or LTT (low tide terrace) with a small section being TBR (transverse bar and rip). Storms are considered

  13. A quantitative analysis of fine scale distribution of intertidal meiofauna in response to food resources

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Gauns, M.

    Fine scale vertical and spatial distribution of meiofauna in relation to food abundance was studied in the intertidal sediment at Dias Beach. The major abiotic factors showed significant changes and progressive fine scale decrease in vertical...

  14. Trajectories of saltating sand particles behind a porous fence

    Science.gov (United States)

    Zhang, Ning; Lee, Sang Joon; Chen, Ting-Guo

    2015-01-01

    Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a 'no-fence' case. A wind fence (ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles.

  15. Beach rock from Goa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.; Wagle, B.G.

    temperature under the beach and inland. However, the thickness depends upon variabilities of precipitation, hinterland, water table fluctuations, temperature changes, composition and changes in sea level. Since the beach rock is formed in the tidal or spray...

  16. Summary of Annual Beach Notifications

    Data.gov (United States)

    U.S. Environmental Protection Agency — To help beachgoers make informed decisions about swimming at U.S. beaches, EPA gathers state-by-state data about beach closings and advisories. Between 1999 and...

  17. First Year Sedimentological Characteristics and Morphological Evolution of an Artificial Berm at Fort Myers Beach, Florida

    Science.gov (United States)

    2011-06-17

    Harbor in 1992 and 1993 resulted in a nearshore berm disposal in Port Canaveral, Florida, offshore of Cocoa Beach. Bodge (1994) evaluated the...samples. The carbonate grains are mostly shell debris. Table 2 provides an example summary of the sedimentological characteristics across a beach...located a 3-6) and f the berm ine sand, a shell debri . Similar to medium sh ly sorted ve e 11 shows a southeas Profile Sou t the toe of offshore (F

  18. Virtual Beach 3: User's Guide

    Science.gov (United States)

    Virtual Beach version 3 (VB3) is a decision support tool that constructs site-specific statistical models to predict fecal indicator bacteria (FIB) concentrations at recreational beaches. VB3 is primarily designed for beach managers responsible for making decisions regarding beac...

  19. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

    2014-01-01

    Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

  20. Southeast Florida Sediment Assessment and Needs Determination (SAND) Study

    Science.gov (United States)

    2014-09-01

    Study team. Linda Lillycrop is the Program Manager of the Regional Sediment Management Program (RSM), Coastal Engineering Branch (HNC), Navigation...report and findings were presented to the SAND Study Team, who requested a third-party peer review be conducted. Coastal Planning and Engineering...feasible for beach nourishment . Carbonate-content testing of vibracore samples (SAND Study vibracores and historic data when available) indicated

  1. Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Haider Abbas Khwaja

    2015-08-01

    Full Text Available Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM and Laser Scanning Microscopy (LSM analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0. Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

  2. A novel wastewater cleaning system for the stone-crushing and sand-making process

    Institute of Scientific and Technical Information of China (English)

    Zhang Wenjun; Li Yanfeng; Tang Jie

    2012-01-01

    The nature of the slurry from the stone-crushing and sand-making processes is analyzed to develop a novel separation process.The process comprises hydro-cyclone separation followed by screening of the fines,clarification,and filtration.Recovering fine sand and clean wastewater for recycle is demonstrated.The +0.045 mm fine sand fraction and-0.045 mm ultra-fine clay in the slurry are separated and recovered.Fine sand that was previously lost and wasted is now recoverable.The cleaned and reused water is as much as 94% of the total.

  3. Altitude of the top of the Sparta Sand and Memphis Sand in three areas of Arkansas

    Science.gov (United States)

    Pugh, Aaron L.; Westerfield, Paul W.; Gonthier, Gerard; Poynter, David T.

    1998-01-01

    The Sparta Sand and Memphis Sand form the second most productive aquifer in Arkansas. The Sparta Sand and Memphis Sand range in thick- ness from 0 to 900 feet, consisting of fine- to medium-grained sands interbedded with layers of silt, clay, shale, and minor amounts of lignite. Within the three areas of interest, the top surface of the Sparta Sand and Memphis Sand dips regionally east and southeast towards the axis of the Mississippi Embayment syncline and Desha Basin. Local variations in the top surface may be attributed to a combination of continued development of structural features, differential compaction, localized faulting, and erosion of the surface prior to subsequent inundation and deposition of younger sediments.

  4. ESTIMATE OF THE HEAVY MINERAL-CONTENT IN SAND AND ITS PROVENANCE BY RADIOMETRIC METHODS

    NARCIS (Netherlands)

    DEMEIJER, RJ; LESSCHER, HME; SCHUILING, RD; ELBURG, ME

    1990-01-01

    A comparison has been made of the traditional gravimetric method for measuring the heavy mineral mass fraction in sand with a method based on the emission of gamma-rays from the uranium and thorium series by radiogenic heavy-minerals. The comparision reveals that beach sand along the Dutch coast may

  5. Natural and Anthropogenic Controls on Beach Morphology from Analysis of Terrestrial Scanning Laser Time Series Data, Waimea Bay, Oahu.

    Science.gov (United States)

    Brooks, B. A.; Becker, J.; Merrifield, M.; Foster, J.; Ericksen, T.; Hilmer, T.; Vitousek, S.

    2008-12-01

    To determine the environmental conditions and timing leading to long time scale (O(years)) and specific event (O(days-hours)) changes in beach morphology we collected terrestrial scanning laser (TLS) topographic time series, offshore wave data, and high resolution digital photographs of the entire beach at Waimea Bay, Oahu from January through June 2007. Each survey had better than 1cm range-resolution, average spot-spacing of 10 cm, and had tilts removed using GPS-based geocoding. The TLS surveys on monthly time-scales quantify the seasonal transition in beach morphology and volume forced by high waves (winter) to small waves (summer). The surveys over daily to hourly time scales quantify the evolution of discrete morphological features. For instance, two surveys taken three hours apart on 27 April 2007 when significant wave height was roughly 0.7m document an order 0.1 m increase in sand elevation occurring along the foreshore indicating active sand accretion following an erosion event on 24 April 2007 when significant wave height was roughly 2.5m. Well-defined fore-beach and back-beach cuspate features were present during the surveys. The elevation difference map shows that the main area of accretion occurred in the fore-beach cusp embayments, i.e., the beach cusps appear to be filling in with sand. We further use the TLS time series data to quantify the subaerial morphologic signal and volumetric beach change budget of foot-traffic on the beach. Our initial observations indicate that the upper portions of the beach, rarely affected by waves but receiving hundreds to thousands of visitors per day, exhibits convex upward character typical of diffusive forcing. We assess whether a diffusive landscape evolution model based on linear or non-linear flux laws describes the temporal and spatial evolution of the upper parts of beaches where wave forcing rarely occurs.

  6. THE APPLICATION OF PEPTIDE NUCLEIC ACID PROBES FOR RAPID DETECTION AND ENUMERATION OF EUBACTERIA, STAPHYLOCOCCUS AUREUS AND PSEUDOMONAS AERUGINOSA IN RECREATIONAL BEACHES OF S. FLORIDA. (R828830)

    Science.gov (United States)

    A novel chemiluminescent in situ hybridization technique using peptide nucleic acids (PNA) was adapted for the detection of bacteria in beach sand and recreational waters in South Florida. The simultaneous detection and enumeration of eubacteria and the novel indicators, S...

  7. Summer Love at Beaches

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Spanish Sand Situated on the Iberian Peninsula in Southwestern Europe, Spain is richly endowed with pic- turesque natural attractions, allur- ing visitors with its pleasant climate, bright sunshine, green hills and limpid waters.

  8. The Sediment and Hydrographic Characteristics of Three Horseshoe Crab Nursery Beaches in Hong Kong

    Institute of Scientific and Technical Information of China (English)

    Helen M.C. Chiu; Brian Morton

    2003-01-01

    Horseshoe crab juveniles have been recorded from sand and sandy-mud nursery beaches at Pak Nai (western New Territories ), San Tau and Shui Hau (Lantau Island), Hong Kong. In order to provide a better understanding of these beaches and to identify those plausible factors which have made them preferred by spawning horseshoe crabs, environmental parameters, including temperature, salinity, pH and dissolved oxygen content of the water, and particle size distribution and organic matter content of the sediments at the three sites, were determined and compared. The hydrographic and sediment data obtained for the three study sites have revealed some common environmental features. The three nursery beaches are relatively remote, and far (in Hong Kong terms) from urbanized and densely populated areas. The beaches are generally well sheltered from strong wave action and inundated regularly by estuarine waters. Horseshoe crab adults tend to select these beaches for spawning as their protected features ensures the laid eggs are less likely to be washed out of the sand, and hatched juveniles can feed on the meiofauna and grow. Sediments of the three beaches largely comprise medium-sized sand particles and are moderately sorted, suggesting medium porosity and good water permeability. Such a sand type, with the generally high oxygen levels in incursing waters, may help create a well-oxygenated micro-environment for the normal development of horseshoe crab eggs, larvae and juveniles. Lantau Island beaches at San Tau and Shui Hau are relatively free from organic pollution, as reflected in generally high dissolved oxygen level, and low BOD5 and ammonia nitrogen values. Pak Nai is, however, more polluted.

  9. The sediment and hydrographic characteristics of three horseshoe crab nursery beaches in hong kong

    Science.gov (United States)

    Chiu, Helen M. C.; Morton, Brian

    2003-04-01

    Horseshoe crab juveniles have been recorded from sand and sandy-mud nursery beaches at Pak Nai (western New Territories), San Tau and Shui Hau (Lantau Island), Hong Kong. In order to provide a better understanding of these beaches and to identify those plausible factors which have made them preferred by spawning horseshoe crabs, environmental parameters, including temperature, salinity, pH and dissolved oxygen content of the water, and particle size distribution and organic matter content of the sediments at the three sites, were determined and compared. The hydrographic, and sediment data obtained for the three study sites have revealed some common environmental features. The three nursery beaches are relatively remote, and far (in Hong Kong terms) from urbanized and densely populated areas. The beaches are generally well sheltered from strong wave action and inundated regularly by estuarine waters. Horseshoe crab adults tend to select these beaches for spawning as their protected features ensures the laid eggs are less likely to be washed out of the sand, and hatched juveniles can feed on the meiofauna and grow. Sediments of the three beaches largely comprise medium-sized sand particles and are moderately sorted, suggesting medium porosity and good water permeability. Such a sand type, with the generally high oxygen levels in incursing waters, may help create a well-oxygenated micro-environment for the normal development of horseshoe crab eggs, larvae and juveniles. Lantau Island beaches at San Tau and Shui Hau are relatively free from organic pollution, as reflected in generally high dissolved oxygen level, and low BOD5 and ammonia nitrogen values. Pak Nai is, however, more polluted.

  10. Sands styrke

    DEFF Research Database (Denmark)

    Jacobsen, H. Moust; Jørgensen, Mogens B.; Poulsen, H. Serup

    1975-01-01

    På grundlag af triaxialforsøg med D=7 og 20 cm og varierende højde på løse og faste lejringer af Blokhussand kan effekten af varierende højde-breddeforhold og spændingsniveau samt skalaeffekten bestemmes. Ved sammenligning med pladeforsøg med overfladelast op til 8 t/m2 kan den almindelige fremga...... fremgangsmåde ved bæreevneberegninger på sand undersøges....

  11. Transport of fine sediment over a coarse, immobile riverbed

    Science.gov (United States)

    Grams, Paul E.; Wilcock, Peter R.

    2014-01-01

    Sediment transport in cobble-boulder rivers consists mostly of fine sediment moving over a coarse, immobile bed. Transport rate depends on several interrelated factors: boundary shear stress, the grain size and volume of fine sediment, and the configuration of fine sediment into interstitial deposits and bed forms. Existing models do not incorporate all of these factors. Approaches that partition stress face a daunting challenge because most of the boundary shear is exerted on immobile grains. We present an alternative approach that divides the bed into sand patches and interstitial deposits and is well constrained by two clear end-member cases: full sand cover and absence of sand. Entrainment from sand patches is a function of their aerial coverage. Entrainment from interstices among immobile grains is a function of sand elevation relative to the size of the immobile grains. The bed-sand coverage function is used to predict the ratio of the rate of entrainment from a partially covered bed to the rate of entrainment from a completely sand-covered bed, which is determined using a standard sand transport model. We implement the bed-sand coverage function in a morphodynamic routing model and test it against observations of sand bed elevation and suspended sand concentration for conditions of nonuniform fine sediment transport in a large flume with steady uniform flow over immobile hemispheres. The results suggest that this approach may provide a simple and robust method for predicting the transport and migration of fine sediment through rivers with coarse, immobile beds.

  12. The mobilization of toxic trace elements due to pyrite oxidation at the mega-nourishment The Sand Motor, the Netherlands

    Science.gov (United States)

    Pit, I.; Doodeman, L.; Van Heteren, S.; van Bruggen, M.; Griffioen, J.

    2014-12-01

    Pilot project "The Sand Motor" is a 21.5 million m3 nourishment of sandy sediment situated along the coast of the Netherlands close to The Hague (figure 1). It was constructed in 2011 and initially spans the shore over a 2.4 km stretch and extends up to 1 km offshore creating a hook-shaped peninsula. Due to wind, waves and currents the Sand Motor will gradually change in shape and eventually be fully incorporated into the dunes and beach. This concept is expected to be more environmentally friendly compared to traditional beach and shoreface nourishments. The aim of this project is to understand how oxidation changed the geochemistry of the sediment applied and to address possible toxic element mobilization. The sediment was taken 10 km out of shore from the sea floor, which was at a depth of 20 m. Grab samples of the upper 25 cm seabed analyzed for geochemical mapping of Southern North Sea sediments, show locally high contents of sulfur, iron and trace elements like arsenic indicating presence of pyrite with impurities. Sediment was removed to a maximum depth of 6 m below sea floor, reaching different geological layers including bog iron ore layers. Different degrees of pyrite oxidation are expected with depth at the Sand Motor. First, minimum oxidation when sediment was deposited from the ship directly by opening the bottom floor, which is now present under water at the deepest part of the nourishment. Second, limited oxidation when sediment was applied from the ship under high pressure through the air, and settled below sea level. Last, maximum oxidation when the same method was used but the sediment remains located in a surface layer having a maximum height of 4 m above sea level. At the Sand Motor, samples were taken of surface water, pore water and sediment from the surface to a depth of 10 m, the bottom of the nourishment. Analyses show that pyrite oxidation has occurred above sea level and mobilization of arsenic is present up to a maximum concentration of

  13. Beach Profiles Characteristics Along Giao Thuy and Hai Hau Coasts,Vietnam: A Field Study

    Institute of Scientific and Technical Information of China (English)

    NGUYEN Viet Thanh; ZHENG Jin-hai; ZHANG Chi

    2012-01-01

    Giao Thuy and Hai Hau coasts are located in Nam Dinh province,Vietnam,with a total coastline of 54.42 km in length.The sea-dike system has been seriously damaged and there have been many dike breaches which caused floods and losses.This situation is considered of a general representative for coastal area in the northern part of Vietnam.A variety of studies have shown that the gradient in the longshore sediment transport rate and the offshore fine sediment lost are the main mechanisms causing the beach erosion.This study presents a field investigation of the beach profiles at Giao Thuy and Hai Hau beaches.Three types of empirical functions for the equilibrium beach profile are applied and compared with the observations.Results show that all observed beach profiles can be described by a single function.However,one specific equilibrium profile equation is not sufficient to assess all beach profiles.In Section 1 of Giao Thuy and Section 3 of Hai Thinh beaches,beach profiles are consistent with the logarithmic function,while the exponential function fits well in Section 2.This difference is explained with respect to coastal morphology,sediment characteristics and hydrodynamic conditions which vary in site.An analysis of the validity of the beach profile functions is recommended for the numerical modeling and engineering designs in this area.

  14. 11 things a geologist thinks an engineer should know about carbonate beaches

    Science.gov (United States)

    Halley, Robert B.; Magoon, Orville T.; Robbins, Lisa L.; Ewing, Lesley

    2002-01-01

    This is a review of the geological aspects of carbonate beaches that a geologist thinks may be useful for an engineer. Classical geologic problems of carbonate beaches, for example how ancient examples are recognized in rock sequences, are of little interest to engineers. Geologists not involved in engineering problems may find it difficult to know what an engineer should understand about carbonate beaches. Nevertheless, there are at least eleven topics that are potentially very useful for engineers to keep in mind. These eleven are chosen with as much thought going into what has been omitted as has been given to the eleven included topics. Some qualifications are in order: First, this paper does not discuss certain kinds of carbonate shorelines that are beyond the scope of engineering issues. For example, this review does not discuss very high-energy carbonate boulder beaches. These beaches are comprised of pieces of carbonate material ganging in size from ten centimeters to meters. Typically, these are high-energy storm deposits formed from pieces of either eroded carbonate rock or other large carbonate pieces such as pieces of large corals. This paper focuses on sand-sized (0.0625–2.0 mm) coastal carbonate deposits. Second, offshore beaches will not be discussed. There are many carbonate beaches that form on banks or shoals exposed at low tide, but our discussion is confined to what most people think of when they go to some tropical island and/or resort and walk out to lay on the beach. Third, this paper does not consider mixed carbonate/quartz sand beaches. While mixed beaches are common, only the end member of purely carbonate sand beaches is considered. Fourth, there will be no order of preference of the eleven topics. And lastly, these eleven topics are not consensus items. These are simply one geologist s thoughts about the aspects of carbonate beaches that would be useful for engineering colleagues to keep in mind. Where possible, general reference is

  15. Response to storm conditions of two different beaches at the Mediterranean coast of Morocco

    Science.gov (United States)

    El Mrini, Aldelmounim; Anfuso, Giorgio; Nachite, Driss; Taaouati, Mohamed

    2010-05-01

    In recent decades the increased demand for the recreational use of beaches has resulted in the uptake of studies on the morphodynamic processes which are acting on beaches. This knowledge is fundamental for appropriate coastal erosion management, suitable tourist use of littoral and for the design and shape of human construction. The Mediterranean sectors of Moroccan littoral investigated in this study, Ksar Rimal and Cabo Negro beaches, are respectively located north and south of Cabo Negro promontory and, over recent years, have been subject to increasing tourist activity. This has consisted mainly of the construction of two tourist ports (Marina Smir and Kabila), residential developments, hotels and a motorway which runs parallel to the coast, affecting the dune ridges and two lagoons which are of great ecological interest. In detail, the dunes located in the backshore at Ksar Rimal beach, are nowadays occupied by summer houses threaten by coastal retreat. A wide, partially urbanized, backshore is observed at Cabo Negro beach. With the intention of characterize the morphodynamic and seasonal behavior and the response of the studied beaches to storm impact, a beach monitoring program was carried out in the period 2006-2008, with special attention to the February-March 2008 stormy period. On analyzing the information obtained, it was possible to characterize the morphology and sedimentology of the studied beaches, and to calculate beach volumetric variations. Ksar Rimal is an open, exposed beach characterized by an intermediate slope (tan β = 0.10) with medium-coarse sands. The beach showed a reflective beach state characterized by plunging breakers. Small morphological seasonal changes were observed, most important morphological and volumetric variations (about 20 m3/m) taking place after winter storms which usually gave rise to a more dissipative beach profile (tan β = 0.05) characterized by spilling breakers. Beach recovery was quite rapid, usually lasting 2

  16. Microalgae associated with Leptoconops breeding sites in selected sandy beaches of Malaysia.

    Science.gov (United States)

    Rohani, A; Khadri, M S; Lee, H L

    2006-12-01

    A study was carried out to investigate correlation between presence of specific microalgal species and Leptoconops biting midge larvae in its breeding habitats. Sand samples containing microalgae were collected from the beach where the midges were most commonly biting and from sand beaches which are potential as breeding habitats of Leptoconops. The survey covered sand beaches from 12 seperate islands. At all sites, the Bacillariophyta constituted the largest representatives of the microalgae community with the majority from the Naviculaceae family. A total of 24 microalgal species were identified from the sand samples collected from the study sites. Sand samples from Kentot Kecil Island had the highest number of algal species (11.0) and the highest algae species diversity ( Shanon-Weiner Diversity Index, H' = 0.884). Besar Island (Johor) had the lowest number of algal species (2.0) whereas Tengol A Island had the lowest algae species diversity (H'=0.234). Highest similarity index was recorded between sand samples collected from Tengol A Island and Tengol B Island (75.0%) followed by Besar Island (Melaka) and Tengol B Island (62.0 %). The variation between other islands were relatively high. Virtually many kinds of algae were found where Leptoconops were breeding but Fragilaria intermedia, Mastigloia minuta and Navicula advena were particularly common.

  17. New methodology for describing the equilibrium beach profile applied to the Valencia's beaches

    Science.gov (United States)

    Aragonés, L.; Serra, J. C.; Villacampa, Y.; Saval, J. M.; Tinoco, H.

    2016-04-01

    Mathematical models used for the understanding of coastal seabed morphology play a key role in beach nourishment projects. These projects have become the fundamental strategy for coastal maintenance during the last few years. Accordingly, the accuracy of these models is vital to optimize the costs of coastal regeneration projects. Planning of such interventions requires methodologies that do not generate uncertainties in their interpretation. A study and comparison of mathematical simulation models of the coastline is carried out in this paper, as well as elements that are part of the model that are a source of uncertainty. The equilibrium profile (EP) and the offshore limit corresponding to the depth of closure (DoC) have been analyzed taking into account different timescale ranges. The results have thus been compared using data sets from three different periods which are identified as present, past and future. Accuracy in data collection for the beach profiles and the definition of the median grain size calculation using collected samples are the two main factors that have been taken into account in this paper. These data can generate high uncertainties and can produce a lack of accuracy in nourishment projects. Together they can generate excessive costs due to possible excess or shortage of sand used for the nourishment. The main goal of this paper is the development of a new methodology to increase the accuracy of the existing equilibrium beach profile models, providing an improvement to the inputs used in such models and in the fitting of the formulae used to obtain seabed shape. This new methodology has been applied and tested on Valencia's beaches.

  18. Tar sand

    Energy Technology Data Exchange (ETDEWEB)

    McLendon, T.R.; Bartke, T.C.

    1990-01-01

    Research on tar sand is briefly discussed. The research program supported by the US Department of Energy (DOE) includes a variety of surface extraction schemes. The University of Utah has process development units (PDU) employing fluidized bed, hot, water-assisted, and fluidized-bed/heat-pipe, coupled combustor technology. Considerable process variable test data have been gathered on these systems: (1) a rotary kiln unit has been built recently; (2) solvent extraction processing is being examined; and (3) an advanced hydrogenation upgrading scheme (hydropyrolysis) has been developed. The University of Arkansas, in collaboration with Diversified Petroleum, Inc., has been working on a fatty acid, solvent extraction process. Oleic acid is the solvent/surfactant. Solvent is recovered by adjusting processing fluid concentrations to separate without expensive operations. Western Research Institute has a PDU-scale scheme called the Recycle Oil Pyrolysis and Extraction (ROPE) process, which combines solvent (hot recycle bitumen) and pyrolytic extraction. 14 refs., 19 figs.

  19. Dispersal of fine sediment in nearshore coastal waters

    Science.gov (United States)

    Warrick, Jonathan A.

    2013-01-01

    Fine sediment (silt and clay) plays an important role in the physical, ecological, and environmental conditions of coastal systems, yet little is known about the dispersal and fate of fine sediment across coastal margin settings outside of river mouths. Here I provide simple physical scaling and detailed monitoring of a beach nourishment project near Imperial Beach, California, with a high portion of fines (40% silt and clay by weight). These results provide insights into the pathways and residence times of fine sediment transport across a wave-dominated coastal margin. Monitoring of the project used physical, optical, acoustic, and remote sensing techniques to track the fine portion of the nourishment sediment. The initial transport of fine sediment from the beach was influenced strongly by longshore currents of the surf zone that were established in response to the approach angles of the waves. The mean residence time of fine sediment in the surf zone—once it was suspended—was approximately 1 hour, and rapid decreases in surf zone fine sediment concentrations along the beach resulted from mixing and offshore transport in turbid rip heads. For example, during a day with oblique wave directions and surf zone longshore currents of approximately 25 cm/s, the offshore losses of fine sediment in rips resulted in a 95% reduction in alongshore surf zone fine sediment flux within 1 km of the nourishment site. However, because of the direct placement of nourishment sediment on the beach, fine suspended-sediment concentrations in the swash zone remained elevated for several days after nourishment, while fine sediment was winnowed from the beach. Once offshore of the surf zone, fine sediment settled downward in the water column and was observed to transport along and across the inner shelf. Vertically sheared currents influenced the directions and rates of fine sediment transport on the shelf. Sedimentation of fine sediment was greatest on the seafloor directly offshore

  20. Experimental Study of Preparation of C70 Manufactured Sand High Strength Concrete with Ultra-Fine Fly Ash%超细粉煤灰制备C70机制砂高强混凝土的试验研究

    Institute of Scientific and Technical Information of China (English)

    黄肖颖

    2013-01-01

    通过对超细粉煤灰掺量、水胶比、集料和胶凝材料体系等配合比参数进行设计和分析,利用超细粉煤灰制备出 C70机制砂高强混凝土,解决了机制砂高强混凝土拌合物黏度大的问题,并对混凝土耐久性能和收缩性能进行了评价。结果表明,该混凝土具有良好的工作性能、力学性能和耐久性能。%C70 manufactured sand high strength concrete was prepared by using ultra-fine fly ash, based on design and analysis of the mix proportion parameters of the ultra-fine fly ash content, water to binder ratio, aggregates and cmentitious materials. The problem of high viscosity of manufactured sand high strength concrete resolved. The performances of durability and shrinkage of concrete were evaluated. The results showed that the concrete had good workability,mechanical and durability properties.

  1. Human-associated methicillin-resistant Staphylococcus aureus from a subtropical recreational marine beach

    Science.gov (United States)

    Reports of Staphylococcus aureus detected in marine environments have occurred since the early 1990’s. This investigation sought to isolate and characterize S. aureus from marine waters and sand at a subtropical recreational beach, with and without bathers present, in order to investigate possible s...

  2. Using LiDAR derivatives to estimate sediment grain size on beaches in False Bay

    CSIR Research Space (South Africa)

    Burns, J

    2017-05-01

    Full Text Available to global and climate change in particular, continues to have a big impact on coastal environments. The vulnerability of the sandy coast is dependent on the physical characteristics such as orientation/exposure, beach slope, and sand grain size...

  3. Studies on nearshore processes at Yarada beach (South of Visakhapatnam harbour) east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Rao, T.V.N.; Rao, D.P.; Rao, B.P.

    induced longshore currents and visual observations on breaker heights and breaker angles were made at 8 stations from January 1978 to January 1979. There was accretion in Yarads Beach with a net addition of about 12,000 m super(3) of sand during the study...

  4. It's in the sand

    OpenAIRE

    Mitchell, Clive

    2016-01-01

    Sand is sand isn’t it? Sand gets everywhere but rather than a nuisance it is a valuable, high-purity raw material. Clive Mitchell, Industrial Minerals Specialist at the British Geological Survey (BGS), talks us through what sand is, what it can be used for and how to find it. His exploration of sand takes us from the deserts of Arabia to the damp sand pits of Mansfield!

  5. Santa Barbara Littoral Cell CRSMP Offshore Sand Sources 2009

    Data.gov (United States)

    California Department of Resources — Offshore sand sources exist at four known locations and potentially other yet to be explored regions within the nearshore coastal shelf. Significant reserves of fine...

  6. Santa Barbara Littoral Cell CRSMP Offshore Sand Sources 2009

    Data.gov (United States)

    California Department of Resources — Offshore sand sources exist at four known locations and potentially other yet to be explored regions within the nearshore coastal shelf. Significant reserves of fine...

  7. GPR studies over the tsunami affected Karaikal beach, Tamil Nadu, south India.

    Digital Repository Service at National Institute of Oceanography (India)

    Loveson, V.J.; Gujar, A.R.; Barnwal, R.P.; Khare, R.; Rajamanickam, G.V.

    is approximately a quarter of the GPR wavelength, and ranges from 0.08 m for saturated sands with 200 MHz antennae to 0.4 m for dry sands with 100 MHz antenna. The application of GPR, especially, in coastal studies is well known and is being widely employed... in identifying and tracing various buried struc- tures and facies in the beaches (Neal and Roberts 2000), dunes, bars, spits (Jol et al. 2002; Shukla et al. 2008) as well as in sand barriers (Meyers et al. 1994; Jol et al. 1996; Costas et al. 2006). Also, the GPR...

  8. Multi-year persistence of beach habitat degradation from nourishment using coarse shelly sediments.

    Science.gov (United States)

    Peterson, Charles H; Bishop, Melanie J; D'Anna, Linda M; Johnson, Galen A

    2014-07-15

    Beach nourishment is increasingly used to protect public beach amenity and coastal property from erosion and storm damage. Where beach nourishment uses fill sediments that differ in sedimentology from native beach sands, press disturbances to sandy beach invertebrates and their ecosystem services can occur. How long impacts persist is, however, unclear because monitoring after nourishment typically only extends for several months. Here, monitoring was extended for 3-4 years following each of two spatially separated, replicate nourishment projects using unnaturally coarse sediments. Following both fill events, the contribution to beach sediments of gravel-sized particles and shell fragments was enhanced, and although diminishing through time, remained elevated as compared to control sites at the end of 3-4 years of monitoring, including in the low intertidal and swash zones, where benthic macroinvertebrates concentrate. Consequently, two infaunal invertebrates, haustoriid amphipods and Donax spp., exhibited suppressed densities over the entire post-nourishment period of 3-4 years. Emerita talpoida, by contrast, exhibited lower densities on nourished than control beaches only in the early summer of the first and second years and polychaetes exhibited little response to nourishment. The overall impact to invertebrates of nourishment was matched by multi-year reductions in abundances of their predators. Ghost crab abundances were suppressed on nourished beaches with impacts disappearing only by the fourth summer. Counts of foraging shorebirds were depressed for 4 years after the first project and 2 years after the second project. Our results challenge the view that beach nourishment is environmentally benign by demonstrating that application of unnaturally coarse and shelly sediments can serve as a press disturbance to degrade the beach habitat and its trophic services to shorebirds for 2-4 years. Recognizing that recovery following nourishment can be slow, studies

  9. DINÂMICA DA PAISAGEM NA PRAIA DE VALHA-ME DEUS, CURURUPU-MA / LANDSCAPE DYNAMICS OF THE BEACH OF VALHA-ME DEUS IN CURURUPU – MA

    Directory of Open Access Journals (Sweden)

    Francisco Wendell Dias Costa

    2017-08-01

    Full Text Available The landscape dynamics in Valha-me Deus beach, located in the county of Cururupu, in the state of Maranhão, Brazil. The study was carried out based on the geosystemic theory and considering the following methodological procedures: bibliographical and cartographic research and analysis of the area of study, field search intended to measure the climatic parameters and the observations according to the dynamics integrated in the landscape, involving the behavior of the morphogenetic agents of climatic, oceanographic, biotic and anthropic origin. The results show that the area is formed an unconsolidated sedimentary formation, constituted of quartz-like sand with fine and very fine size, submitted to climatic and oceanographic agents and processes which determine intense alterations of the morphology, allowing it to infer a high degree of vulnerability of the natural landscape, despite the low interference from men as the morphogenetic agent. The thermo averages and the wind speed are higher in the dry season if compared to the rain season, and the action of the waves and the ocean currents determines the morphodymanic pattern of the beach.

  10. Seasonal impact on beach morphology and the status of heavy mineral deposition – central Tamil Nadu coast, India

    Indian Academy of Sciences (India)

    V Joevivek; N Chandrasekar

    2014-02-01

    The aim of the present research was to investigate the seasonal impact on nearshore beach dynamics and the status of heavy mineral distribution along central Tamil Nadu coast, India. Beach profile measurements were made in 10 profiling sites between Thirukadaiyur and Velankanni on monthly and seasonal basis from January 2011 to July 2012. Using beach profile data, variation in beach width, slope and volumetric changes have been calculated. Beach slope and nearshore wave parameters were used to quantify the longshore sediment transport rate. Beaches between Thirukadaiyur and Karaikkal attained predominant transport rate in northern direction whereas, the rest of the beaches are in southern direction. The seasonal action of wind and wave currents create nearshore bar during northeast (NE) monsoon and frequent berms at tidal zone during southwest (SW) monsoon. Surface sediment samples were collected in each location for quantifying the heavy mineral weight percentage during the period of pre- and post-Thane cyclone. Sediments were also studied by X-ray diffraction (XRD) to evaluate the changes and occurrence of heavy minerals in beach sands. The XRD results show that sediments in the study area have enriched heavy mineral distribution even after strong cyclonic event. It confirms the redistribution of heavy mineral deposits present in the coast. The results suggested that monsoonal action has influenced the seasonal changes in beach morphology and it does not affect the heavy mineral distribution.

  11. Seasonal impact on beach morphology and the status of heavy mineral deposition - central Tamil Nadu coast, India

    Science.gov (United States)

    Joevivek, V.; Chandrasekar, N.

    2014-02-01

    The aim of the present research was to investigate the seasonal impact on nearshore beach dynamics and the status of heavy mineral distribution along central Tamil Nadu coast, India. Beach profile measurements were made in 10 profiling sites between Thirukadaiyur and Velankanni on monthly and seasonal basis from January 2011 to July 2012. Using beach profile data, variation in beach width, slope and volumetric changes have been calculated. Beach slope and nearshore wave parameters were used to quantify the longshore sediment transport rate. Beaches between Thirukadaiyur and Karaikkal attained predominant transport rate in northern direction whereas, the rest of the beaches are in southern direction. The seasonal action of wind and wave currents create nearshore bar during northeast (NE) monsoon and frequent berms at tidal zone during southwest (SW) monsoon. Surface sediment samples were collected in each location for quantifying the heavy mineral weight percentage during the period of pre- and post-Thane cyclone. Sediments were also studied by X-ray diffraction (XRD) to evaluate the changes and occurrence of heavy minerals in beach sands. The XRD results show that sediments in the study area have enriched heavy mineral distribution even after strong cyclonic event. It confirms the redistribution of heavy mineral deposits present in the coast. The results suggested that monsoonal action has influenced the seasonal changes in beach morphology and it does not affect the heavy mineral distribution.

  12. Applying Uav and Photogrammetry to Monitor the Morphological Changes Along the Beach in Penghu Islands

    Science.gov (United States)

    Lu, Cheng-Hao

    2016-06-01

    Penghu islands, in the southern Taiwan Strait, is a remnant of a middle-late Miocene basaltic shield volcano. We present a procedure to use UAV (Unmanned Aerial Vehicles) to perform photogrammetry survey and monitoring analysis in beach evolution scenarios. The aim of this study is to understand spatial-temporal change along the sandy beach in Penghu islands, especially as for the effects of typhoon and coastal structures. According to the study result, this example of application is provided to show the results and the potential of this methodology in real beach changes. In addition, we found the typhoon and coastal structures play important roles to shape the beach morphology and its evolution. The result of beach monitoring reveals that the reduction and change of sand volume in Shanshui beach resulted from the placement of detached breakwater complexes. This coastal structure likely resulted in the development of tombolo and therefor make the beach unstable and subject to conduct rip current and more erosion.

  13. The extraction of bitumen from western tar sands. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  14. The extraction of bitumen from western tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  15. PAH concentrations in Coquina (Donax spp.) on a sandy beach shoreline impacted by a marine oil spill.

    Science.gov (United States)

    Snyder, Richard A; Vestal, Alexandra; Welch, Christina; Barnes, Gracie; Pelot, Robert; Ederington-Hagy, Melissa; Hileman, Fredrick

    2014-06-15

    The BP MC252 well failure in the Gulf of Mexico, April 2010 caused concern for crude oil and polycyclic aromatic hydrocarbon (PAHs) exposure along the sandy beaches of the Florida Panhandle. We began collections of Coquina clams (Donax spp.) from the surf zone of Florida Panhandle beaches to monitor PAH contamination to compliment analysis of surf zone sand samples. These clams had higher levels of PAHs relative to ambient sand, and this allowed us to continue to monitor PAH levels after sand concentrations fell below limits of detection. PAH levels in the Coquina tissues were highly variable, perhaps indicative of the heterogeneous distribution of oil and tar on the beaches and exposure to tar particles. Overall, PAH levels decreased continuously in both sand and Coquina tissues, reaching limits of detection within one and two years respectively after oil landed on Florida Panhandle beaches. Our work suggests these surf zone molluscs may be used to monitor pollutant exposure along high energy sandy beach shorelines.

  16. Industrial sand and gravel

    Science.gov (United States)

    Dolley, T.P.

    2013-01-01

    Domestic production of industrial sand and gravel in 2012 was about 49.5 Mt (55 million st), increasing 13 percent compared with that of 2011. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

  17. Performance of a data-driven technique to changes in wave height and its effect on beach response

    Directory of Open Access Journals (Sweden)

    Jose M. Horrillo-Caraballo

    2016-01-01

    Full Text Available In this study the medium-term response of beach profiles was investigated at two sites: a gently sloping sandy beach and a steeper mixed sand and gravel beach. The former is the Duck site in North Carolina, on the east coast of the USA, which is exposed to Atlantic Ocean swells and storm waves, and the latter is the Milford-on-Sea site at Christchurch Bay, on the south coast of England, which is partially sheltered from Atlantic swells but has a directionally bimodal wave exposure. The data sets comprise detailed bathymetric surveys of beach profiles covering a period of more than 25 years for the Duck site and over 18 years for the Milford-on-Sea site. The structure of the data sets and the data-driven methods are described. Canonical correlation analysis (CCA was used to find linkages between the wave characteristics and beach profiles. The sensitivity of the linkages was investigated by deploying a wave height threshold to filter out the smaller waves incrementally. The results of the analysis indicate that, for the gently sloping sandy beach, waves of all heights are important to the morphological response. For the mixed sand and gravel beach, filtering the smaller waves improves the statistical fit and it suggests that low-height waves do not play a primary role in the medium-term morphological response, which is primarily driven by the intermittent larger storm waves.

  18. Governance in a beach seine fishery

    NARCIS (Netherlands)

    Medard, Modesta; Dijk, Van Han; Hebinck, Paul; Geheb, Kim

    2016-01-01

    Beach seine gear is one of the prominent fishing gears in Nile Perch fishery. Before Nile Perch was introduced to the lake, beach seines the species targeted with beach seine were Tilapia, Bagrus, Haplochromis, Protopterus and Labeo. In 1994, beach seines were banned in Tanzania and by 2004, this

  19. Galveston Island, Texas, Sand Management Strategies

    Science.gov (United States)

    2016-07-01

    68 Figure 28. Jetty segment used for computation of aeolian sand transport. Background photograph 22 May 2012...113 Figure 68 . Total shoreline change after 50 years for 500,000 yd3 placed every 2 years in different locations...The berm at Ft. Myers, FL, was constructed with dredged material from Matanzas Pass. The dredged material contained greater than 10% fines, which

  20. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between...... void ratio and permeability is established....

  1. Morphological developments after a beach and shoreface nourishment at Vlugtenburg beach, the Netherlands

    Science.gov (United States)

    de Schipper, M. A.; de Vries, S.; Ranasinghe, R.; Reniers, A. J. H. M.; Stive, M. J. F.

    2012-04-01

    For the last decades Dutch coastal policy requires sand nourishments to mitigate the effects of coastal erosion. Over time, the nourishment strategy has evolved from direct protection approach to a feeder approach; instead of placing the sand on the beach or dune where it directly benefits safety, sand is placed on the shoreface or alongshore concentrated. Subsequently natural processes redistribute the sand over the profile and alongshore. With the shift in nourishment approach, a study was started to investigate in detail how nourished sand is redistributed in space and time. Here we present results from a high resolution bathymetric survey campaign conducted at Vlugtenburg beach at the south west coast of the Netherlands. At this site a beach and shoreface nourishment of 5.4 million m3 was installed in spring 2009, moving the shoreline approximately 250 m forward. Since the completion of the project, a total of 22 profiles were measured monthly extending from the dunefoot to 9 m below mean sea level. These surveys are executed using walking GPS surveys for the subaerial part and jetski surveys for the subaqueous part. Observations show that the morphodynamic evolution can be characterized by two stages; first a period of rapid changes followed by a period of more stable topography. In the first period, 12 to 15 months after construction, a large cross shore (offshore) movement of the nourished sand is found. The cross shore movement results from a rapid adaptation of the construction profile (characterized by a steep foreshore slope from -2 to -4 m) to a more natural profile with a large subtidal bar. A sediment budget analysis over all 28 surveys up to present shows a gradual loss of volume. As topographic changes below the -8 m and above +3 m are small, it is most likely that the majority of the sediment deficit can be contributed to alongshore losses. Furthermore, the domain itself is subdivided in various coastal sections, revealing that the cross shore

  2. Novel foraging in the swash zone on Pacific sand crabs (Emerita analoga, Hippidae) by mallards

    Science.gov (United States)

    Lafferty, Kevin D.; McLaughlin, John P.; Dugan, Jenifer E.

    2013-01-01

    Mallards (Anas platyrhynchos) have been observed foraging on intertidal Pacific sand crabs (Hippidae, Emerita analoga) in the swash zone of sandy beaches around Coal Oil Point Reserve, California, and several other beaches on the west coast since at least November 2010. Unlike foraging shorebirds, Mallards do not avoid incoming swashes. Instead, the incoming swash lifts and deposits them down the beach. Shorebirds and diving ducks commonly feed on sand crabs, but sand crabs appear to be a novel behavior and food source for Mallards. Previous surveys of beaches did not report foraging Mallards on regional beaches, whereas foraging Mallards were common in contemporary (recent) surveys and anecdotal reports. Observations of this potentially new behavior were separated by as much as 1,300 km, indicating that this was not a local phenomenon. Mallards foraged singly, in pairs, and in flocks. An expansion of diet to sand crabs carries risks of exposure to surf, human disturbance, high salt intake, and transmission of acanthocephalan and trematode parasites for Mallards but has the benefit of providing a dependable source of animal protein.

  3. Basic Remote Sensing Investigations for Beach Reconnaissance.

    Science.gov (United States)

    Progress is reported on three tasks designed to develop remote sensing beach reconnaissance techniques applicable to the benthic, beach intertidal...and beach upland zones. Task 1 is designed to develop remote sensing indicators of important beach composition and physical parameters which will...ultimately prove useful in models to predict beach conditions. Task 2 is designed to develop remote sensing techniques for survey of bottom features in

  4. Carbonate Beaches: A Balance Between Biological and Physical Processes

    Science.gov (United States)

    Nairn, R.; Risk, M.

    2004-12-01

    Carbonate beaches are a unique example of the interaction between biological processes, creating the sediments, and physical processes, moving and often removing the sediments. On the sediment supply side, carbonate sediments are born, not made. They exist in dynamic equilibrium between production and destruction. Following the creation of carbonate sediment in coral reef and lagoon environments, the sediments are moved shoreward to the beach, transport along the shore and sometimes, eventually lost offshore, often as the result of tropical storms. Comprehensive studies of the balance between the supply and loss of carbonate sediments and beach dynamics have been completed for the islands of Mauritius and Barbados. Field studies and remote sensing (Compact Airborne Spectrometry Imaging) have been applied to develop carbonate sediment production rates for a range of reef and lagoon conditions. Using GIS, these production rates have been integrated to determine sediment supply rates for different segments of the coastline. 1-D and 2-D models of waves, hydrodynamics, sediment transport and morphodynamics were set-up and tested against observed beach response to storm events or a sequence of storm events. These complex deterministic models are not suitable for application over periods of decades. However, it was possible to characterize storm events by the extent of sand loss, and relate this to key descriptive factors for groups of storm events, thereby encapsulating the erosion response. A long-term predictive tool for evaluating beach erosion and accretion response, over a period of several decades, was developed by combining the supply rates for carbonate sediment and the encapsulated representation of the loss rates through physical processes. The ability of this predictive tool was successfully tested against observed long term beach evolution along sections of the coast in Barbados and Mauritius using air photo analysis in GIS for shoreline change over periods

  5. Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takayuki, E-mail: sasaki@nucleng.kyoto-u.ac.jp [Kyoto University, Department of Nuclear Engineering (Japan); Rajib, Mohammad [Bangladesh Atomic Energy Commission, Nuclear Minerals Unit, Atomic Energy Research Establishment (Bangladesh); Akiyoshi, Masafumi; Kobayashi, Taishi; Takagi, Ikuji [Kyoto University, Department of Nuclear Engineering (Japan); Fujii, Toshiyuki [Kyoto University, Research Reactor Institute (Japan); Zaman, Md. Mashrur [Bangladesh Atomic Energy Commission, Nuclear Minerals Unit, Atomic Energy Research Establishment (Bangladesh)

    2015-06-15

    The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of {sup 40}K. The maximum values of {sup 232}Th and {sup 238}U, estimated from the radioactivity of {sup 208}Tl and {sup 234}Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed.

  6. Eastern Scheldt Sand, Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

    The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...

  7. Patterns of sand fractions influence on microalgae of the marine coast

    Directory of Open Access Journals (Sweden)

    Anastasiya Snigirova

    2015-04-01

    Full Text Available To study effect of grain size on microalgae a new method is proposed: sand of different fractions is glued to the surface of microscope slides. Microalgae abundance was higher on fine sand grains (<0,25 mm. To forecast microalgae abundance the pattern is proposed depending on size of sand grains. 

  8. 1933 Long Beach, USA Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 5 kilometers southwest of Newport Beach. Seriously affected area: 1,200 square kilometers. Damage: $40 million. Schools were among the buildings most severely...

  9. Human Health at the Beach

    Science.gov (United States)

    ... day at the beach are from swimming. Food poisoning from improperly refrigerated picnic lunches may also have ... simple steps to protect against overexposure to UV radiation as well as how to check the UV ...

  10. Horry County Beach Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Horry County has coordinated with DHEC OCRM to fully inventory, analyze, and documenteach of the ten required elements for an approvable local comprehensive beach...

  11. Aeolian transport of seagrass (Posidonia oceanica) beach-cast to terrestrial systems

    Science.gov (United States)

    Jiménez, Maria A.; Beltran, Rafel; Traveset, Anna; Calleja, Maria Ll; Delgado-Huertas, Antonio; Marbà, Núria

    2017-09-01

    The annual export of the Mediterranean seagrass (Posidonia oceanica) litter to adjacent beaches and coastal dunes was quantified by examining the fortnight evolution of seagrass beach-cast volume on two beaches in the NW Mediterranean (Son Real and Es Trenc, Mallorca Island, Spain) for two years and analyzing the wind speed and direction obtained from the closest Meteorological Spanish Agency surface weather stations. The decomposition stage of the deposits was examined by analyzing the total hydrolysable amino acids, its percentage distribution and derived degradation indexes. Prevalent winds exceeding 6 m s-1, the coastline morphology and type of terrestrial vegetation determine the annual dynamics of the seagrass beach-cast. In the most protected beach (Son Real) the seagrass beach-cast remained nearly stationary during the two studied years while it exhibited wide annual fluctuations in the less protected one (Es Trenc). The amounts of P. oceanica wrack washed on Son Real and Es Trenc beaches, respectively, were estimated at 309 kg DW m coastline-1 yr-1 and 1359 kg DW m coastline-1 yr-1. They supplied between 20 kg CaCO3 m coastline-1 yr-1 and 47 kg CaCO3 m coastline-1 yr-1. Between 54% (Son Real) and 70% (Es Trenc) of seagrass beach-cast, respectively accounting for 1.5 kg N m coastline-1 yr-1 and 8.6 kg N m coastline-1 yr-1, were annually exported from the beaches to adjacent dune systems. Our results reveal that Mediterranean seagrass meadows might be an important source of materials, including sand and nutrients, for adjacent terrestrial systems, able to support their functioning.

  12. Aeolian transport of seagrass ( Posidonia oceanica ) beach-cast to terrestrial systems

    KAUST Repository

    Jiménez, Maria A.

    2017-06-29

    The annual export of the Mediterranean seagrass (Posidonia oceanica) litter to adjacent beaches and coastal dunes was quantified by examining the fortnight evolution of seagrass beach-cast volume on two beaches in the NW Mediterranean (Son Real and Es Trenc, Mallorca Island, Spain) for two years and analyzing the wind speed and direction obtained from the closest Meteorological Spanish Agency surface weather stations. The decomposition stage of the deposits was examined by analyzing the total hydrolysable amino acids, its percentage distribution and derived degradation indexes. Prevalent winds exceeding 6 m s−1, the coastline morphology and type of terrestrial vegetation determine the annual dynamics of the seagrass beach-cast. In the most protected beach (Son Real) the seagrass beach-cast remained nearly stationary during the two studied years while it exhibited wide annual fluctuations in the less protected one (Es Trenc). The amounts of P. oceanica wrack washed on Son Real and Es Trenc beaches, respectively, were estimated at 309 kg DW m coastline−1 yr−1 and 1359 kg DW m coastline−1 yr−1. They supplied between 20 kg CaCO3 m coastline−1 yr−1 and 47 kg CaCO3 m coastline−1 yr−1. Between 54% (Son Real) and 70% (Es Trenc) of seagrass beach-cast, respectively accounting for 1.5 kg N m coastline−1 yr−1 and 8.6 kg N m coastline−1 yr−1, were annually exported from the beaches to adjacent dune systems. Our results reveal that Mediterranean seagrass meadows might be an important source of materials, including sand and nutrients, for adjacent terrestrial systems, able to support their functioning.

  13. Creep Behavior of Frozen Sand.

    Science.gov (United States)

    1981-06-01

    temperature and stress range. There was a 2strong stress dependance to S (r =0.95) for saturated Manchester Fine Sand which does not agree with RPT. The...Curves at High Stress 161 Ratio D/Du = 0.505 for Frozen HF’S at w=10% IV-20 Minimum Strain Rate Dependance on Stress 162 Ratio for Frozen MFS IV-21 Minimum...Strain Rate Dependance on Relative 163 Density for Frozen MFS IV-22 Temperature Stage Test on Frozen Saturated 164 MFS under a Load of D=9.24MPa Fig

  14. Mineralogy, chemistry and radioactivity of the heavy minerals in the black sands, along the northern coast of Egypt

    Science.gov (United States)

    Abdel-Karim, Abdel-Aal M.; Zaid, Samir M.; Moustafa, Mohammed I.; Barakat, Mohammed G.

    2016-11-01

    Three hundreds and six black sand samples have been collected from the beach areas along the northern coast of Egypt, parallel and perpendicular to the shoreline. The mineralogy and chemistry of the economic heavy minerals were studied. The grain size distribution of the studied economic minerals shows a unimodal class that mostly in the very fine sand size. The microscopic investigation indicates that the study area is enriched with six economic heavy minerals. These are ilmenite, magnetite, garnet, zircon, rutile and monazite; in addition to leucoxene, arranged in decreasing order of their abundance. The studied black sands suggest a reserve of 329, 183, 24, 21, 7, 1 and 14 thousand tons of ilmenite, magnetite, garnet, zircon, rutile, monazite and leucoxene, respectively. The spherical magnetite grains are higher in Fe2O3 than those of euhedral shaped grains. Ilmenite grains display sub-rounded to euhedral shapes. The altered ilmenite grains have higher TiO2 and lower Fe2O3 in comparison with the euhedral fresh ones. Garnet occurs as angular (49%), sub-spherical (45%), spherical (5%) and euhedral grains (1%). Garnet grains containing mineral inclusions represent 10% of their concentrate. The euhedral garnet grains have Al, Fe, Mn, Mg and Ca that arranged in decreasing order of their abundance. The magnetic zircon fraction obtained from their bulk concentrate is particularly rich in colored grains (70%). Their common colors are red and brown with some malacons. The reddish-brown color of zircon may be due to iron oxide stains. Some magnetic zircon grains are enriched in Hf and REEs contents. Rutile grains are sub-to well rounded (70%), and rich in TiO2. Monazite is enriched in Ce, La, Nd, Th and U. Detectable inclusions of gold, copper, lead, galena, cinnabar, platinum group elements (PGES) and silver are recorded in cassiterite. The radiometric measurements revealed that the black sands of the western zone (4 km2) have high values of specific activity, absorbed

  15. Critical state of sand matrix soils.

    Science.gov (United States)

    Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

    2014-01-01

    The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803-0.998, 0.144-0.248, and 1.727-2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated.

  16. Critical State of Sand Matrix Soils

    Directory of Open Access Journals (Sweden)

    Aminaton Marto

    2014-01-01

    Full Text Available The Critical State Soil Mechanic (CSSM is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803–0.998, 0.144–0.248, and 1.727–2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated.

  17. Sand and nest temperatures and an estimate of hatchling sex ratio from the Heron Island green turtle ( Chelonia mydas) rookery, Southern Great Barrier Reef

    Science.gov (United States)

    Booth, David T.; Freeman, Candida

    2006-11-01

    Sand and nest temperatures were monitored during the 2002-2003 nesting season of the green turtle, Chelonia mydas, at Heron Island, Great Barrier Reef, Australia. Sand temperatures increased from ˜ 24°C early in the season to 27-29°C in the middle, before decreasing again. Beach orientation affected sand temperature at nest depth throughout the season; the north facing beach remained 0.7°C warmer than the east, which was 0.9°C warmer than the south, but monitored nest temperatures were similar across all beaches. Sand temperature at 100 cm depth was cooler than at 40 cm early in the season, but this reversed at the end. Nest temperatures increased 2-4°C above sand temperatures during the later half of incubation due to metabolic heating. Hatchling sex ratio inferred from nest temperature profiles indicated a strong female bias.

  18. Landing Techniques in Beach Volleyball

    Science.gov (United States)

    Tilp, Markus; Rindler, Michael

    2013-01-01

    The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ2(2) = 18.19, p volleyball revealed overall differences both in men (χ2(2) = 161.4, p volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key Points About 1/3 of all jumping actions in beach volleyball result in a landing on one foot. Especially following block situations men land on one foot more often than women. Landing techniques are related to different techniques and positions. Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions. PMID:24149150

  19. The Influence of Ephemeral Beaches on Alongshore Variability of Hard-rock Cliff Erosion

    Science.gov (United States)

    Vann Jones, E. C.; Rosser, N. J.; Brain, M.; Varley, S. J.

    2015-12-01

    The role of abrasion of rock cliffs is typically considered in the long-term presence of a beach. During monthly monitoring of hard rock cliff erosion along the North Yorkshire coast, UK, we have observed a number of small ephemeral beaches of highly variable duration and extent. The erosive significance of the temporary presence of sediment at the cliffs is unknown and we set out to examine whether observed alongshore variability in erosion can be linked to the presence of ephemeral beaches. We explore the temporal and spatial variability in sediment deposition and transport along a low-sediment rock coast foreshore, the controlling marine conditions and the effects on cliff erosion. We focus on a 500 m wide embayment set into 70 m high hard rock cliffs consisting of horizontally bedded Jurassic mudstone, shale, siltstone and sandstone. The bay has a wide, shallow gradient foreshore up to 300 m wide with highly variable topography. With the exception of an ephemeral beach (of widths up to approximately 150 m alongshore and 10 m cross-shore) the rock foreshore is typically sand-free, with failed material from the cliffs quickly removed from the cliff toe by the sea leaving only boulders. The high tidal range (6 m) and storm wave environment of the North Sea result in variable marine conditions at the site. We use magnetic sand tracers and a grid of foreshore and cliff face magnets to examine the sand transport across the foreshore and to identify the vertical extent of cliff face impacted by sand. We monitor the driving marine conditions on the foreshore using a network of current meters and wave pressure sensors. Erosion of the cliff face across the whole bay is monitored at high-resolution using terrestrial laser scanning to examine the spatial distribution of abrasion and the influence of the ephemeral beach.

  20. Abundancias poblacionales, crecimiento y mortalidad natural de la macroinfauna de crustáceos en dos tipos morfodinámicos de playas arenosas del sur de Chile Population abundances, growth and natural mortality of the crustacean macroinfauna at two sand beach morphodynamic types in southern Chile

    Directory of Open Access Journals (Sweden)

    HERALDO CONTRERAS

    2003-12-01

    íodo primavera-verano; durante el segundo, mostraron sus máximas abundancias durante octubre en ambas playas. Las curvas de crecimiento y parámetros de crecimiento de O. tuberculata, E. braziliensis y E. hirsuticauda no difirieron significativamente entre playas, aun cuando O. tuberculata tendió a crecer más rápido en Calfuco. Las curvas de crecimiento y parámetros de crecimiento de E. analoga fueron diferentes solo para las hembras, las que tuvieron mayor crecimiento en el sitio disipativo. Las mortalidades naturales de las cuatro especies no difirieron significativamente entre playas. Así, la mayoría de nuestros resultados no soportan nuestra hipótesis, sugiriendo que otros factores, aparte de las morfodinámica de la playa, son importantes en explicar la variabilidad espacial en las abundancias poblacionales y biología poblacional de la macroinfauna de playas arenosasMonthly samplings were carried out during 1994-1996 at an intermediate and at a dissipative sandy beaches of southern Chile (Calfuco and Mehuín, respectively; ca. 39º S, to evaluate the predictions of the swash exclusion hypothesis on the population abundances and life history of the crustacean macroinfauna inhabiting the intertidal of that beaches. It is hypothesized that only true intertidal species (i.e., that directly affected by the swash will be affected by differences in beach morphodynamic types. That species were the cirolanid isopods Excirolana braziliensis and Excirolana hirsuticauda and the anomuran crab Emerita analoga. On the other hand, the almost supralittoral amphipod Orchestoidea tuberculata should not be affected by differences in beach morphodynamic types. The total population abundances of O. tuberculata and E. analoga were significantly higher at the intermediate beach of Calfuco, that of E. braziliensis and E. hirsuticauda at the dissipative beach of Mehuín. While the abundances of ovigerous females of O. tuberculata and E. analoga were higher at Calfuco, that of the ovigerous

  1. The erosion of the beaches on the coast of Alicante: Study of the mechanisms of weathering by accelerated laboratory tests.

    Science.gov (United States)

    López, I; López, M; Aragonés, L; García-Barba, J; López, M P; Sánchez, I

    2016-10-01

    One of the main problems that coasts around the world present, is the regression and erosion of beaches. However, the factors involved in these processes are unclear. In this study, the influence of sediment erosion on beach regression has been analysed. In order to do that, a three-step investigation has been carried out. Firstly, coastline variations of four Spanish beaches have been analysed. Secondly, a study on sediment position along the beach profile has been developed. Finally, the process that beach sediments undergo along the surf zone when they are hit by the incident waves has been simulated by an accelerated particle weathering test. Samples of sand and shells were subjected to this accelerated particle weathering test. Results were supplemented with those from carbonate content test, XRD, SEM and granulometric analysis. Results shows a cross-shore classification of sediments along the beach profile in which finer particles move beyond offshore limit. Besides, it was observed that sediment erosion process is divided into three sages: i) particles wear due to crashes ii) dissolution of the carbonate fraction, and iii) breakage and separation of mineral and carbonate parts of particles. All these processes lead to a reduction of particle size. The mechanism responsible of beach erosion would consist of multiples and continuous particle location exchanges along the beach profile as a consequence of grain-size decrease due to erosion.

  2. Evaluation of a small beach nourishment project to enhance habitat suitability for horseshoe crabs

    Science.gov (United States)

    Jackson, N.L.; Smith, D.R.; Tiyarattanachai, R.; Nordstrom, K.F.

    2007-01-01

    This field study evaluates the effect of nourishing an estuarine beach with gravel to enhance spawning rates by horseshoe crabs. A total of 564??m3 of coarse sand and gravel were emplaced in two 90??m-long treatment segments at Bowers Beach, Delaware, USA from 9 to 11 April 2002. Field data were gathered between 6 April and 24 May 2002 to characterize the two fill segments and the un-nourished segments between them as well as two control segments at the adjacent Ted Harvey Beach. Sediment samples were taken from the foreshore surface and at depth before and after the nourishment. Bay water levels, wave heights, and beach ground water characteristics were monitored over a 12-hour tidal cycle at one of the nourished (15 May 2002) and the unnourished segment (16 May 2002) at Bowers Beach and at one of the control segments at Ted Harvey Beach (21 May 2002) using piezometers and pressure transducers inserted in wells. The beaches were cored to estimate the density of horseshoe crab eggs deposited during the spawning season. Horseshoe crab eggs were buried in pouches at 0.15 to 0.20??m depth for 30 to 40??days to evaluate their survival in developing into embryo or larval stage. Bulk sediment samples were taken to evaluate moisture characteristics near locations where egg pouches were buried. Density of spawning females at Bowers Beach was 1.04??m- 2 in 2001 and 1.20??m- 2 in 2002. These rates are lower than at Ted Harvey Beach but reveal an increase in spawning while Ted Harvey Beach underwent a considerable decrease (2.63??m- 2 to 1.35??m- 2). Sediments low on the foreshore remained nearly saturated throughout the tidal cycle at both beaches. The average hydraulic conductivity on the upper foreshore at the non-treatment section at Bowers Beach (0.19??cm s- 1) was less than at Ted Harvey Beach (0.27??cm s- 1), and the finer, better sorted sediments at depth at Bowers Beach resulted in a higher porosity, creating greater moisture retention potential. Egg development was

  3. 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

  4. 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

  5. Sedimentation process of saturated sand under impact loading

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Junfeng; MENG; Xiangyue

    2005-01-01

    The initial small inhomogeneity of saturated sand could be amplified during the sedimentation process after liquefaction, and cracks could be observed in the sand column. Layers of fine sand could also be found at the exact place where cracks developed and disappeared. The phenomena and the whole process were experimentally shown by X-rays images. To account for the phenomena, a linearized stability analysis of the sedimentation of saturated sand was conducted; however, it did not produce a satisfactory result. A three-phase flow model describing the transportation of fine sand is presented in this paper. It is shown that such a kind of erosion/deposition model was qualitatively in good agreement with the experimental observation.

  6. Citizen science datasets reveal drivers of spatial and temporal variation for anthropogenic litter on Great Lakes beaches.

    Science.gov (United States)

    Vincent, Anna; Drag, Nate; Lyandres, Olga; Neville, Sarah; Hoellein, Timothy

    2017-01-15

    Accumulation of anthropogenic litter (AL) on marine beaches and its ecological effects have been a major focus of research. Recent studies suggest AL is also abundant in freshwater environments, but much less research has been conducted in freshwaters relative to oceans. The Adopt-a-BeachTM (AAB) program, administered by the Alliance for the Great Lakes, organizes volunteers to act as citizen scientists by collecting and maintaining data on AL abundance on Great Lakes beaches. Initial assessments of the AAB records quantified sources and abundance of AL on Lake Michigan beaches, and showed that plastic AL was >75% of AL on beaches across all five Great Lakes. However, AAB records have not yet been used to examine patterns of AL density and composition among beaches of all different substrate types (e.g., parks, rocky, sandy), across land-use categories (e.g., rural, suburban, urban), or among seasons (i.e., spring, summer, and fall). We found that most AL on beaches are consumer goods that most likely originate from beach visitors and nearby urban environments, rather than activities such as shipping, fishing, or illegal dumping. We also demonstrated that urban beaches and those with sand rather than rocks had higher AL density relative to other sites. Finally, we found that AL abundance is lowest during the summer, between the US holidays of Memorial Day (last Monday in May) and Labor Day (first Monday in September) at the urban beaches, while other beaches showed no seasonality. This research is a model for utilizing datasets collected by volunteers involved in citizen science programs, and will contribute to AL management by offering priorities for AL types and locations to maximize AL reduction. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Multidecadal Shoreline Evolution Due to Large-scale Beach Nourishment in Japan

    Science.gov (United States)

    Banno, M.; Takewaka, S.; Kuriyama, Y.

    2016-12-01

    A large-scale beach nourishment in the Netherlands, the Sand Engine, is getting attention as a new type of nourishment. As a similar case in Japan, here, we investigated morphological changes from 1961 to 2013 on the Hasaki coast, where approximately 50 million cubic meters of sands were dumped into the nearshore zone. The Hasaki coast, which is located in the eastern Japan facing the Pacific Ocean, has 16 km long sandy beach. From 1965 to 1977, approximately 50 million cubic meters of sediments were dumped into the nearshore zone on the north side of the beach for disposal of the earth and sand generated during the construction of the Kashima Port, which is an artificially-excavated port. A part of the shoreline-advanced area due to the dump was reclaimed for a land space. Therefore, in practice, approximately 26 million cubic meters of them was the volume of the sediment supply contributed to the morphological change. The volume is comparable to the nourishment of the Sand Engine, of which the volume is 21.5 million cubic meters. An increase in the sediment budgets due to the dump resulted in the mean shoreline advance of approximately 40 meters from 1969 to 1984. After that, although the advance was abated from 1984 to 1993, the shoreline began to advance again from 1993. As the result, the mean shoreline position in 2013 was located approximately 70 meters seaward compared to the position in 1961.

  8. The influence of fluvial dynamics and North Atlantic swells on the beach habitat of leatherback turtles at Grande Riviere Trinidad.

    Science.gov (United States)

    Darsan, Junior; Jehu, Adam; Asmath, Hamish; Singh, Asha; Wilson, Matthew

    2016-09-15

    Grande Riviere beach, located on the north coast of Trinidad, West Indies, is internationally recognised as a critical habitat/nesting ground for the endangered leatherback turtles (Dermochelys coriacea). Episodic extreme flooding of the Grande Riviere River led to the shifting of the river mouth and resulted in backshore beach erosion, with the most recent recorded event occurring in 2012. Following this event, the construction of a sand dam to arrest further erosion which threatened coastal infrastructure, precipitated a host of new problems ranging from beach instability to public health threats. In January 2013, high energy swell waves naturally in-filled the erosion channel, and the beach recovery continued over the successive months, thereby rendering the intervention in the previous year questionable. This paper presents a geomorphological analysis of beach dynamics for Grande Riviere, within the context of this erosion event. Data on beach profiles, sediment and coastal processes were collected using standard geomorphological techniques. Beach topographic analysis and water quality tests on impounded water in the erosion channel were conducted. Results indicate that the event created an erosion channel of 4843.42 m(3) over a contiguous area of 2794.25 m(2). While swell waves were able to naturally infill the channel, they also eroded 17,762 m(3) of sand overall across the beach. Water quality tests revealed that the impounded water was classified as a pollutant, and created challenges for remediation. Hydrologic and coastal geomorphologic interplay is responsible for the existence and sustainability of this coastal system. It is also evident that the beach system is able to recover naturally following extreme events. Our results demonstrate that effective and integrated management of such critical habitats remains dependent upon continuous monitoring data which should be used to inform policy and decision making.

  9. Groundwater flow due to a nonlinear wave set-up on a permeable beach

    Directory of Open Access Journals (Sweden)

    Anna Przyborska

    2014-06-01

    Full Text Available Water flow through the beach body plays an important role in the biological status of the organisms inhabiting the beach sand. For tideless seas, the groundwater flow in shallow water is governed entirely by the surface wave dynamics on the beach. As waves propagate towards the shore, they become steeper owing to the decreasing water depth and at some depth, the waves lose their stability and start to break. When waves break, their energy is dissipated and the spatial changes of the radiation stress give rise to changes in the mean sea level, known as the set-up. The mean shore pressure gradient due to the wave set-up drives the groundwater circulation within the beach zone. This paper discusses the circulation of groundwater resulting from a nonlinear set-up. The circulation of flow is compared with the classic Longuet-Higgins (1983 solution and the time series of the set-up is considered for a 24 h storm. Water infiltrates into the coastal aquifer on the upper part of the beach near the maximum run-up and exfiltration occurs on the lower part of the beach face near the breaking point.

  10. 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

  11. 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.

  12. Influence green sand system by core sand additions

    OpenAIRE

    N. Špirutová; J. Beňo; V. Bednářová; J. Kříž; M. Kandrnál

    2012-01-01

    Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron) are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this co...

  13. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Borup, Marianne; Hedegaard, Jette

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development og the theory of building up pore pressure in sand, L. B. Ibsen 1993....

  14. Evaluation of Bajo Blanco Sandbar as a Potential Beach Nourishment Borrow Site for Eroding Beaches in Rincon, Puerto Rico

    Science.gov (United States)

    Rojas, C. A.; Canals, M.

    2016-02-01

    The municipality of Rincón, Puerto Rico is recognized for its world-class surfing beaches. Unfortunately, the coast from Punta Higüero to Punta Cadena in Rincón is experiencing long-term erosion (Thieler 2007), which has caused the destruction of many beachfront homes and hotels and had negative impacts on the local tourism-driven economy. The purpose of this project is to evaluate whether the nearby Bajo Blanco sandbar, located just offshore of these eroded beaches, could be used as a possible beach nourishment borrow site. A high-resolution bathymetric survey of Bajo Blanco sandbar was conducted along with a grain size analysis to compare the grain size distribution of the Bajo Blanco sandbar with the sediment properties of the eroded beaches. It was found that the sediment from Bajo Blanco is finer yet may be suitable as beach fill material for these beaches according to Dean's overfill ratio. Compatibility analysis suggests a total volume of sandbar sediment of approximately 685,555 cubic meters to allow successful beach equilibrium. To evaluate the potential effects of the sand extraction on the nearshore wave climate, numerical simulations were performed using the spectral wave model of the USACE Coastal Modeling System (CMS-Wave). Wave model results for several dredging scenarios suggest that wave energy flux concentrates around the shoal causing an increase in wave height at the northern and southern edges of the shoal. Therefore, conservation of energy leads to a reduction of wave energy flux shoreward of the shoal, causing a shadow of reduced wave height. In addition, the Tres Palmas Marine reserve is located just north of Bajo Blanco sandbar and features some of the healthiest Elkorn Corals in the Caribbean. To avoid excessive sedimentation of these reefs during dredging activities, the Particle Tracking Module (PTM), integrated in the Surface-water Modeling System (SMS), was used to evaluate the Lagrangian particle transport processes along Bajo

  15. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...

  16. The effect of off-road vehicles on barrier beach invertebrates at Cape Cod and Fire Island National Seashores

    Science.gov (United States)

    Kluft, J. M.; Ginsberg, Howard S.

    2009-01-01

    The effects of off-road vehicles (ORVS) on invertebrates inhabiting seaweed debris (wrack) and supratidal sands on energetic beaches in the northeastern United States were studied at Cape Cod National Seashore, MA, and Fire Island, NY. Cores, wrack quadrats, and pitfall traps were used to sample four beaches, which all had vehicle-free sections in close proximity to ORV corridors, allowing for paired traffic/no-traffic samples at these sites. A manipulative experiment was also performed by directly driving over nylon-mesh bags filled with eelgrass (Zostera marina) wrack that had been colonized by beach invertebrates, then subjected to treatments of high-, low-, and no-traffic. Pitfall trap samples had consistently higher overall invertebrate abundances in vehicle-free than in high-traffic zones on all four beaches. In contrast, both wrack quadrats (with intact wrack clumps) and the cores taken directly beneath them did not show consistent differences in overall invertebrate abundances in areas open and closed to vehicles. Overall abundance of wrack was lower on beaches with vehicle traffic. The talitrid amphipod Talorchestia longicornis and the lycosid spider Arctosa littoralis, both of which roam widely on the beach and burrow in supratidal bare sands as adults, were always less abundant in beach sections open to vehicle traffic, regardless of the sampling method used. Other invertebrates, such as oligochaetes (family Enchytraeidae) and Tethinid flies (Tethina parvula), both of which spend most of their lives within/beneath wrack detritus, showed either no response or a positive response to traffic disturbance. In the drive-over experiment, different species responded differently to traffic. The tenebrionid beetle Phaleria testacea (85% larvae) was significantly less abundant in disturbed wrack bags than in controls, while Tethina parvula (90% larvae) showed the reverse trend. Therefore, ORVs adversely affected beach invertebrates, both by killing or displacing

  17. LANDING TECHNIQUES IN BEACH VOLLEYBALL

    Directory of Open Access Journals (Sweden)

    Markus Tilp

    2013-09-01

    Full Text Available The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ²(2 = 18.19, p < 0.01 but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (χ²(2 = 161.4, p < 0.01 and women (χ²(2 = 84.91, p < 0.01. Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball

  18. Laboratory studies of dune sand for the use of construction industry in Sri Lanka

    Science.gov (United States)

    de Silva Jayawardena, Upali; Wijesuriya, Roshan; Abayaweera, Gayan; Viduranga, Tharaka

    2015-04-01

    With the increase of the annual sand demand for the construction industry the excessive excavation of river sand is becoming a serious environmental problem in Sri Lanka. Therefore, it is necessary to explore the possibility for an alternative to stop or at least to minimize river sand mining activities. Dune sand is one of the available alternative materials to be considered instead of river sand in the country. Large quantities of sand dunes occur mainly along the NW and SE coastal belt which belong to very low rainfall Dry Zone coasts. The height of dune deposits, vary from 1m to about 30 meters above sea level. The objective of this paper is to indicate some studies and facts on the dune sand deposits of Sri Lanka. Laboratory studies were carried out for visual observations and physical properties at the initial stage and then a number of tests were carried out according to ASTM standards to obtain the compressive strength of concrete cylinders and mortar cubes mixing dune sand and river sand in different percentages keeping a constant water cement ratio. Next the water cement ratio was changed for constant dune sand and river sand proportion. Microscopic analysis shows that the dune sand consist of 95 % of quartz and 5 % of garnet, feldspar, illmenite and other heavy minerals with clay, fine dust, fine shell fragments and organic matters. Grains are sub-rounded to angular and tabular shapes. The grain sizes vary from fine to medium size of sand with silt. The degree of sorting and particle size observed with dune sands are more suited with the requirement of fine aggregates in the construction industry. The test result indicates that dune sand could be effectively used in construction work without sieving and it is ideal for wall plastering due to its'-uniformity. It could also be effectively used in concrete and in mortars mixing with river sand. The best mixing ratio is 75% dune sand and 25% river sand as the fine aggregate of concrete. For mortar the mixing

  19. California Shoreline Sand Retention: Existing Structure Performance and Future Potential

    Science.gov (United States)

    Kinsman, N. E.; Griggs, G. B.

    2008-12-01

    Amidst rising sea level, climate change and expanding coastal populations, sandy beaches are frequently exposed to erosional processes. Effective sea level rise will lead to recreational beach loss as a result of coastal inundation. Beach nourishment is growing in popularity as a mitigation approach to meet the increasing need to protect coastal resources. The practice of beach nourishment along high energy shorelines, such as in California, is often improved by the construction of sediment retention structures (groins) to enhance project lifespans. However, our current ability to design effective littoral barriers is extremely limited. An underutilized and cost-effective resource for critically analyzing engineered retention structure performance is the record of existing structures within California. The impacts of 205 structures along California's 1700 km shoreline have been systematically explored though measurements collected from aerial imagery and historic shoreline positions. The findings of this study suggest that approximately 30 million m3 of sand and 18% of California's total exposed sandy beach area is presently retained in fillet and salient beaches associated with man-made structures such as groins, breakwaters, piers and jetties. Preliminary results suggest statistically significant correlations between structure effectiveness and key characteristics such as orientation, littoral cell position and construction materials. The central product of this study is a complete and robust GIS catalog of retention structures along California's coastline. A detailed analysis of historic structure performance combined with a systematically measured record of structure characteristics for the entire state results in a useful product to help coastal planners use the lessons of the past to plan future beach management.

  20. Varadero Beach, Hicacos Península, Cuba: relief génesis and evolution, and environmental experience linked to its artificial regeneration

    Directory of Open Access Journals (Sweden)

    José Ramón Hernández Santana

    2012-03-01

    Full Text Available The coastal system constitutes one of the most fragüe systems of the Earth's surface, specially in cumulative áreas such as beaches. Dumping sand is one of the main ways to artificially promote the sedimentary enrichment and temporary stability of beaches, thus contributing to their environmental protection and sustainable development. The present work improves our knowledge on the structure, morphology, génesis and dynamícs of the peninsular relief of Hicacos, Cuba, fundamentally at its northern sector, focusing on its use and optimized management. The study proposes an evolutionary model for its geomorphological consolidation; it describes the environmental experiences related to dumping sand in Varadero beach in 1998 as a beach-recovering measure, and suggests a number of preventive and corrective measures that favor geomorphic stability, in harmony with current and projected resorts and services.

  1. Concentración de metales pesados (Cu, Ni, Zn, Cd, Pb en la biota y sedimentos de una playa artificial, en la bahía San Jorge 23°S, norte de Chile Heavy metals concentration (Cu, Ni, Zn, Cd, Pb, in biota and sediments of an artificial beach, in San Jorge bay 23°S, northern Chile

    Directory of Open Access Journals (Sweden)

    Gabriel Castro

    2012-07-01

    that area. Equidistant stations were located at each beach in which the organisms were extracted, that ranged from the intertidal to the subtidal. Sediment samples were taken at each beach and slopes were determined with the Emery method. The granulometric analysis evidenced the predominance of medium sand in El Lenguado beach, and medium and fine sand in Paraíso beach. The organic matter content was greater in El Lenguado. In Paraíso beach were determined 5 phylum/superclass, grouped in 19 taxa, while in El Lenguado were found 4 phylum/superclass grouped in cc taxa. The metal content in sediments and in the majority of organisms shows higher values in Paraíso beach. This results along with the Chilean and American quality norms suggest an evident deterioration of the environmental quality of Paraíso beach, which is demonstrated by an increase in the concentrations of these metals from its construction, which exceed the established limits by both norms.

  2. 78 FR 35596 - Special Local Regulation; Long Beach Regatta, Powerboat Race, Atlantic Ocean, Long Beach, NY

    Science.gov (United States)

    2013-06-13

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; Long Beach Regatta, Powerboat Race, Atlantic Ocean, Long Beach, NY AGENCY: Coast Guard, DHS. ACTION: Notice of Proposed Rulemaking... Atlantic Ocean off Long Beach, NY during the Long Beach Regatta Powerboat Race scheduled for August...

  3. 33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Annual Fort Myers Beach air show; Fort Myers Beach, FL. 100.736 Section 100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Fort Myers Beach air show; Fort Myers Beach, FL. (a)(1) Regulated Area. The regulated area is formed...

  4. 77 FR 50019 - Safety Zone; Cocoa Beach Air Show, Atlantic Ocean, Cocoa Beach, FL

    Science.gov (United States)

    2012-08-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Cocoa Beach Air Show, Atlantic Ocean, Cocoa... establishing a temporary safety zone on the waters of the Atlantic Ocean located east of Cocoa Beach, Florida during the Cocoa Beach Air Show. The Cocoa Beach Air Show will include aircraft engaging in...

  5. Improving Oasis Beach: Creating a sustainable and attractive beach around hotel Oasis in Varadero Cuba

    NARCIS (Netherlands)

    Vrolijk, E.F.; Poelhekke, L.; Schlepers, M.H.; De Boer, G.G.

    2014-01-01

    In the North of Cuba, the Oasis beach area is situated. The beach suffers from structural erosion and earlier measures to deal with this have not succeeded. In this project, a solution is offered to reach two goals: foremost, a beach improvement to the Oasis beach sector and second, a halt to the s

  6. 76 FR 54703 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

    Science.gov (United States)

    2011-09-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Myrtle Beach Triathlon, Atlantic... Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach Triathlon, which is comprised of a series of triathlon races, is scheduled to take place on Saturday, October 8, 2011 and...

  7. 76 FR 37700 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

    Science.gov (United States)

    2011-06-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Myrtle Beach Triathlon, Atlantic... Waterway in Myrtle Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach Triathlon, which is comprised of a series of triathlon races, is scheduled to take place on Saturday, October...

  8. 77 FR 14321 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

    Science.gov (United States)

    2012-03-09

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Myrtle Beach Triathlon, Atlantic... Waterway in Myrtle Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach Triathlon, which is comprised of a series of triathlon races, is scheduled to take place on Saturday, October...

  9. Lake Beach Monitoring Locations in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Monitored state lake beach locations in Iowa. The Watershed Monitoring & Assessment Section of the Iowa DNR takes regular water samples at these listed beaches...

  10. Santa Barbara Littoral Cell CRSMP Beaches 2009

    Data.gov (United States)

    California Department of Resources — Several criteria were used for beach selection. BEACON 's Coastal Regional Sediment Management Plan included all of the most popular beaches in the two counties...

  11. Amchitka beach surveys, 1978-1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Surveys of 16 beaches on Amchitka Island began 28 October 1978 as part of Alaska Beached Bird Survey. The purpose of the surveys is to provide baseline data on...

  12. Santa Barbara Littoral Cell CRSMP Beaches 2009

    Data.gov (United States)

    California Department of Resources — Several criteria were used for beach selection. BEACON 's Coastal Regional Sediment Management Plan included all of the most popular beaches in the two counties...

  13. 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...

  14. Behavior and identification of ephemeral sand dunes at the backshore zone using video images

    Directory of Open Access Journals (Sweden)

    PEDRO V. GUIMARÃES

    2016-01-01

    Full Text Available ABSTRACT The backshore zone is transitional environment strongly affected by ocean, air and sand movements. On dissipative beaches, the formation of ephemeral dunes over the backshore zone plays significant contribution in the beach morphodynamics and sediment budget. The aim of this work is to describe a novel method to identify ephemeral dunes in the backshore region and to discuss their morphodynamic behavior. The beach morphology is identified using Argus video imagery, which reveals the behavior of morphologies at Cassino Beach, Rio Grande do Sul, Brasil. Daily images from 2005 to 2007, topographic profiles, meteorological data, and sedimentological parameters were used to determine the frequency and pervasiveness of these features on the backshore. Results indicated that coastline orientation relative to the dominant NE and E winds and the dissipative morphological beach state favored aeolian sand transport towards the backshore. Prevailing NE winds increase sand transportation to the backshore, resulting in the formation of barchans, transverse, and barchanoid-linguiod dunes. Precipitation inhibits aeolian transport and ephemeral dune formation and maintains the existing morphologies during strong SE and SW winds, provided the storm surge is not too high.

  15. Behavior and identification of ephemeral sand dunes at the backshore zone using video images.

    Science.gov (United States)

    Guimarães, Pedro V; Pereira, Pedro S; Calliari, Lauro J; Ellis, Jean T

    2016-09-01

    The backshore zone is transitional environment strongly affected by ocean, air and sand movements. On dissipative beaches, the formation of ephemeral dunes over the backshore zone plays significant contribution in the beach morphodynamics and sediment budget. The aim of this work is to describe a novel method to identify ephemeral dunes in the backshore region and to discuss their morphodynamic behavior. The beach morphology is identified using Argus video imagery, which reveals the behavior of morphologies at Cassino Beach, Rio Grande do Sul, Brasil. Daily images from 2005 to 2007, topographic profiles, meteorological data, and sedimentological parameters were used to determine the frequency and pervasiveness of these features on the backshore. Results indicated that coastline orientation relative to the dominant NE and E winds and the dissipative morphological beach state favored aeolian sand transport towards the backshore. Prevailing NE winds increase sand transportation to the backshore, resulting in the formation of barchans, transverse, and barchanoid-linguiod dunes. Precipitation inhibits aeolian transport and ephemeral dune formation and maintains the existing morphologies during strong SE and SW winds, provided the storm surge is not too high.

  16. Structural aspects of the surf-zone fish assemblage at King's Beach, Algoa Bay, South Africa: Long-term fluctuations

    Science.gov (United States)

    Lasiak, Theresa A.

    1984-04-01

    Regular collections of fish were obtained from the surf-zone at King's Beach, Algoa Bay. A total of 3970 fish, representing 50 species was caught with a coarse net and 16 857 fish, representing 37 species, were caught with a fine net. Predominant species were the blacktail, Diplodus sargus; the sand steenbras, Lithognathus mormyrus; the mullet, Liza richardsoni; the gorrie, Pomadasys olivaceum; the white stumpnose, Rhabdosargus globiceps; the sandshark, Rhinobatos annulatus; and the streepie, Sarpa salpa. No seasonal trends were discernible in the overall abundance or species diversity. The species composition of the dominant component of the fish assemblage varied considerably. This indicated instability in the community structure and cast doubts on the applicability of a classic community concept and the use of diversity indices. Neither classification nor correspondence analysis were of any use in identifying a characteristic species component. Multiple regression analysis indicated that short-term variations in wind conditions might be a primary determinant of fluctuations in abundance. The lack of seasonality in the community parameters may reflect the fact that short-term variability masks seasonal perturbations.

  17. Geophysical and Geotechnical Determination of Sand Resources on the Florida Atlantic Continental Shelf: Preliminary Results

    Science.gov (United States)

    Finkl, C. W.; Andrews, J. L.; Suthard, B. C.; Robertson, W.

    2007-12-01

    The State of Florida is committed to maintaining beaches to sustain beach width and protect coastal infrastructure. Nearshore sand resources must be identified and cataloged for potential beach nourishment projects in response to sea-level rise and increased tropical storm activity. Given the vast length of Florida coastline, application of a variety of remote sensing techniques are required for measuring large areas in a short amount of time. The study area encompasses a shelf area of about 2,053,220 ha (20,532 km2) from Miami to the Georgia State line (about 653 km shoreline length) and extends up to 27 km offshore to about the 45 m isobath offshore Jacksonville. The continental shelf along the east coast of the Florida peninsula contains a wide range of seafloor environments that lie above the Florida-Hatteras Slope on the shoreface and inner, middle, and outer shelf floors. This study used Airborne Laser Bathymetry (ALB), 3D digital terrain models based on reformatted NOAA bathymetric data, sidescan sonar, and seismic reflection profiling to map seafloor geomorphological conditions that range from coralline-algal reef systems to drowned karst, submerged paleo shorelines (drowned beach ridge plains), and buried paleo channels. Seatruthing of morphosedimentary features is achieved via jetprobe and vibracore surveys in the study of inter-reefal sand troughs, ebb-tidal deltas, transverse bars, shoals, sand waves, ridges, and banks. Preliminary results, which visualize seafloor topography as color-ramped morphoforms, indicate the presence of sedimentary deposits that may constitute viable sand resources for shore protection in the form of beach renourishment. Use of ALB and reformatted NOAA bathymetric data in the form of 3D terrain models permits classification of submarine landform topologies that was heretofore not possible using isobaths. The combination of multiple remote sensing methods showed the spatial distribution of morphosedimentary features and provided

  18. Distribution and quantity of microplastic on sandy beaches along the northern coast of Taiwan.

    Science.gov (United States)

    Kunz, Alexander; Walther, Bruno A; Löwemark, Ludvig; Lee, Yao-Chang

    2016-10-15

    Plastic pollution is now ubiquitous in the world's oceans, and studies have shown macroplastic and microplastic pollution of beaches in several East Asian countries. However, to our knowledge, no study of microplastic pollution has been conducted in Taiwan yet. Therefore, we collected sand samples from four beaches along the northern coast of Taiwan in 2015 and extracted microplastic particles using a saturated NaCl solution. Microplastic particles were identified using synchrotron-based FTIR spectroscopy. We recovered 4 to 532 particles from eight 0.0125m(3) samples, with a total of 1097 particles weighing 0.771g. A negative trend between the size of the particles and their numbers was documented. We thus established that microplastic pollution was ubiquitous along Taiwan's northern coast. Future research should more comprehensively sample beaches around the entirety of Taiwan's coast, and special emphasis should be placed on identifying different sources and movements of microplastic.

  19. Differentiating Experts' Anticipatory Skills in Beach Volleyball

    Science.gov (United States)

    Canal-Bruland, Rouwen; Mooren, Merel; Savelsbergh, Geert J. P.

    2011-01-01

    In this study, we examined how perceptual-motor expertise and watching experience contribute to anticipating the outcome of opponents' attacking actions in beach volleyball. To this end, we invited 8 expert beach volleyball players, 8 expert coaches, 8 expert referees, and 8 control participants with no beach volleyball experience to watch videos…

  20. Differentiating Experts' Anticipatory Skills in Beach Volleyball

    Science.gov (United States)

    Canal-Bruland, Rouwen; Mooren, Merel; Savelsbergh, Geert J. P.

    2011-01-01

    In this study, we examined how perceptual-motor expertise and watching experience contribute to anticipating the outcome of opponents' attacking actions in beach volleyball. To this end, we invited 8 expert beach volleyball players, 8 expert coaches, 8 expert referees, and 8 control participants with no beach volleyball experience to watch videos…

  1. Sand laser-ablation as source of elements laser isotope separation: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, N.A.S.; Destro, M.G.; Vasconcelos, G; Neri, J.W.; Silveira, C.A.B.; Riva, R. [Institute for Advanced Studies, Sao Jose dos Campos, SP (Brazil)]. E-mail: nicolau@ieav.cta.br

    2008-07-01

    This paper presents preliminary results of emission spectroscopy experiments, performed with the aim to verify the presence of monoatomic neutral material in the jet produced by laser ablation of simple and complex targets. All studied materials (copper, graphite, alumina and beach sand) showed emission of single atoms, indicating the presence of monoatomic material in the ablated plume. (author)

  2. Initial spreading of a mega feeder nourishment : Observations of the Sand Engine pilot project

    NARCIS (Netherlands)

    de Schipper, Matthieu A.; de Vries, Sierd; Ruessink, Gerben|info:eu-repo/dai/nl/169093360; de Zeeuw, Roeland C.; Rutten, Jantien; van Gelder-Maas, Carola; Stive, Marcel J F

    2016-01-01

    Sand nourishments are a widely applied technique to increase beach width for recreation or coastal safety. As the size of these nourishments increases, new questions arise on the adaptation of the coastal system after such large unnatural shapes have been implemented. This paper presents the initial

  3. Plant-feeding nematodes in coastal sand dunes: occurrence, host specificity and effects on plant growth

    NARCIS (Netherlands)

    Brinkman, E.P.; Duyts, H.; Karssen, G.; Stoel, C.D.; Putten, van der W.H.

    2015-01-01

    Aims Coastal sand dunes have a well-established abiotic gradient from beach to land and a corresponding spatial gradient of plant species representing succession in time. Here, we relate the distribution of plant-feeding nematodes with dominant plant species in the field to host specialization and

  4. Reconstruction of the coastal morphodynamics of the Fulong-beach dune field in north-eastern Taiwan

    Science.gov (United States)

    Dörschner, Nina; Böse, Margot; Frechen, Manfred

    2010-05-01

    The Fulong-beach dune field is located at the north-eastern coast of Taiwan. Built up of medium and fine grained quartz rich sand, it represents a unique feature of only few kilometres along the east coast of Taiwan. This unique sedimentological regime makes the area most perfectly suitable for age estimations by optically stimulated luminescence (OSL). The dune field is crossed by the Shuangsi-river, which flows into the Pacific Ocean. The coastal area is subjected to very dynamic conditions in the transition zone between land and sea. Due to the constant force of marine and aeolian processes from tides, weather and sediment accumulation by rivers, it is a continuously changing area. Taiwan is located in a very active tectonic zone with high elevation rates, which reach from 4 mm per year at the east coast up to 7 mm per year in the southern parts of the island. Furthermore Taiwan is affected by medial 3.8 typhoons per year and minor earthquakes nearly occur every day (LIN ET AL. 2006). The consequences are high rates of erosion and sediment transport during very short time periods. The Fulong-beach coastal area is densely populated and proud for being a tourism destination. At the northern end of the dune field the Lungmen nuclear power plant is currently under construction. Four separate dune ridges could be identified from a digital elevation model and from field mapping. During the field campaign in October and November 2009 17 samples were taken for OSL-dating (MURRAY ET AL. 1995) out of the four dune ridges as well as out of a more than 30 m high elevated outcrop cut by the Shuangsi-river. The measurement and the evaluation of the OSL-samples will provide us an insight into the duration and intensity of the processes affecting the coastal area of Taiwan during the Holocene. We will give an outline during the poster presentation of the methodical approach and the morphodynamical processes affecting the Fulong-beach dune field in north-eastern Taiwan

  5. Incipient Motion of Sand and Oil Agglomerates

    Science.gov (United States)

    Nelson, T. R.; Dalyander, S.; Jenkins, R. L., III; Penko, A.; Long, J.; Frank, D. P.; Braithwaite, E. F., III; Calantoni, J.

    2016-12-01

    Weathered oil mixed with sediment in the surf zone in the northern Gulf of Mexico after the 2010 Deepwater Horizon oil spill, forming large mats of sand and oil. Wave action fragmented the mats into sand and oil agglomerates (SOAs) with diameters of about 1 to 10 cm. These SOAs were transported by waves and currents along the Gulf Coast, and have been observed on beaches for years following the spill. SOAs are composed of 70%-95% sand by mass, with an approximate density of 2107 kg/m³. To measure the incipient motion of SOAs, experiments using artificial SOAs were conducted in the Small-Oscillatory Flow Tunnel at the U.S. Naval Research Laboratory under a range of hydrodynamic forcing. Spherical and ellipsoidal SOAs ranging in size from 0.5 to 10 cm were deployed on a fixed flat bed, a fixed rippled bed, and a movable sand bed. In the case of the movable sand bed, SOAs were placed both proud and partially buried. Motion was tracked with high-definition video and with inertial measurement units embedded in some of the SOAs. Shear stress and horizontal pressure gradients, estimated from velocity measurements made with a Nortek Vectrino Profiler, were compared with observed mobility to assess formulations for incipient motion. For SOAs smaller than 1 cm in diameter, incipient motion of spherical and ellipsoidal SOAs was consistent with predicted critical stress values. The measured shear stress at incipient motion of larger, spherical SOAs was lower than predicted, indicating an increased dependence on the horizontal pressure gradient. In contrast, the measured shear stress required to move ellipsoidal SOAs was higher than predicted, even compared to values modified for larger particles in mixed-grain riverine environments. The laboratory observations will be used to improve the prediction of incipient motion, transport, and seafloor interaction of SOAs.

  6. Using UAS Hyperspatial RGB Imagery for Identifying Beach Zones along the South Texas Coast

    Directory of Open Access Journals (Sweden)

    Lihong Su

    2017-02-01

    Full Text Available Shoreline information is fundamental for understanding coastal dynamics and for implementing environmental policy. The analysis of shoreline variability usually uses a group of shoreline indicators visibly discernible in coastal imagery, such as the seaward vegetation line, wet beach/dry beach line, and instantaneous water line. These indicators partition a beach into four zones: vegetated land, dry sand or debris, wet sand, and water. Unmanned aircraft system (UAS remote sensing that can acquire imagery with sub-decimeter pixel size provides opportunities to map these four beach zones. This paper attempts to delineate four beach zones based on UAS hyperspatial RGB (Red, Green, and Blue imagery, namely imagery of sub-decimeter pixel size, and feature textures. Besides the RGB images, this paper also uses USGS (the United States Geological Survey Munsell HSV (Hue, Saturation, and Value and CIELUV (the CIE 1976 (L*, u*, v* color space images transformed from an RGB image. The four beach zones are identified based on the Gray Level Co-Occurrence Matrix (GLCM and Local Binary Pattern (LBP textures. Experiments were conducted with South Padre Island photos acquired by a Nikon D80 camera mounted on the US-16 UAS during March 2014. The results show that USGS Munsell hue can separate land and water reliably. GLCM and LBP textures can slightly improve classification accuracies by both unsupervised and supervised classification techniques. The experiments also indicate that we could reach acceptable results on different photos while using training data from another photo for site-specific UAS remote sensing. The findings imply that parallel processing of classification is feasible.

  7. Characteristics of coastal dune topography and vegetation in environments recently modified using beach fill and vegetation plantings, Veneto, Italy.

    Science.gov (United States)

    Nordstrom, Karl F; Gamper, Ulrike; Fontolan, Giorgio; Bezzi, Annelore; Jackson, Nancy L

    2009-12-01

    Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation. Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush.

  8. 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.

  9. Anne Fine

    Directory of Open Access Journals (Sweden)

    Philip Gaydon

    2015-04-01

    Full Text Available An interview with Anne Fine with an introduction and aside on the role of children’s literature in our lives and development, and our adult perceptions of the suitability of childhood reading material.Since graduating from Warwick in 1968 with a BA in Politics and History, Anne Fine has written over fifty books for children and eight for adults, won the Carnegie Medal twice (for Goggle-Eyes in 1989 and Flour Babies in 1992, been a highly commended runner-up three times (for Bill’s New Frock in 1989, The Tulip Touch in 1996, and Up on Cloud Nine in 2002, been shortlisted for the Hans Christian Andersen Award (the highest recognition available to a writer or illustrator of children’s books, 1998, undertaken the positon of Children’s Laureate (2001-2003, and been awarded an OBE for her services to literature (2003. Warwick presented Fine with an Honorary Doctorate in 2005.Philip Gaydon’s interview with Anne Fine was recorded as part of the ‘Voices of the University’ oral history project, co-ordinated by Warwick’s Institute of Advanced Study.

  10. Virtual Beach 3: user's guide

    Science.gov (United States)

    Cyterski, Mike; Brooks, Wesley; Galvin, Mike; Wolfe, Kurt; Carvin, Rebecca; Roddick, Tonia; Fienen, Mike; Corsi, Steve

    2014-01-01

    Virtual Beach version 3 (VB3) is a decision support tool that constructs site-specific statistical models to predict fecal indicator bacteria (FIB) concentrations at recreational beaches. VB3 is primarily designed for beach managers responsible for making decisions regarding beach closures or the issuance of swimming advisories due to pathogen contamination. However, researchers, scientists, engineers, and students interested in studying relationships between water quality indicators and ambient environmental conditions will find VB3 useful. VB3 reads input data from a text file or Excel document, assists the user in preparing the data for analysis, enables automated model selection using a wide array of possible model evaluation criteria, and provides predictions using a chosen model parameterized with new data. With an integrated mapping component to determine the geographic orientation of the beach, the software can automatically decompose wind/current/wave speed and magnitude information into along-shore and onshore/offshore components for use in subsequent analyses. Data can be examined using simple scatter plots to evaluate relationships between the response and independent variables (IVs). VB3 can produce interaction terms between the primary IVs, and it can also test an array of transformations to maximize the linearity of the relationship The software includes search routines for finding the "best" models from an array of possible choices. Automated censoring of statistical models with highly correlated IVs occurs during the selection process. Models can be constructed either using previously collected data or forecasted environmental information. VB3 has residual diagnostics for regression models, including automated outlier identification and removal using DFFITs or Cook's Distances.

  11. Enhanced microbubbles assisted cleaning of diesel contaminated sand.

    Science.gov (United States)

    Agarwal, Ashutosh; Liu, Yu

    2017-07-25

    In this article, we investigated the effect of low intensity pulsed ultrasound (US), temperature and salinity on cleaning efficacy of fine bubbles with diameter <50μm for diesel contaminated sands. About 47% and 76% diesel removal was achieved from 10% (w/w) diesel contaminated fine and medium sands respectively, after 30min treatment with 40kHz low intensity intermittent pulsed US together with MBs in contrast to 41% and 68% diesel removal while treatment with MBs alone. The effect of high temperature was found to be prominent during the initial stages of cleaning. In addition, MBs generated in 599mM saline water efficiently removed 85% diesel from fine sand within 30min in contrast to only 41% diesel removal with MBs in fresh water. This study provides evidence for developing highly efficient MBs based chemical free technology for diesel contaminated sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Manmade vulnerability of the Cancun Beach system: the case of hurricane Wilma

    Energy Technology Data Exchange (ETDEWEB)

    Casarin, Rodolfo Silva; Baldwin, Edgar Mendoza [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico (Mexico); Martinez, Gabriel Ruiz; Marino-Tapia, Ismael [Laboratorio de Procesos Costeros, Centro de Investigacion y Estudios Avanzados del Instituto Politecnico Nacional, Merida (Mexico); Vanegas, Gregorio Posada [Instituto EPOMEX, Universidad Autonoma de Campeche (Mexico); Mancera, Edgar Escalante [Instituto de Ciencias del Mar y Limnologia, Universidad Autonoma de Mexico, Unidad Academica Puerto Morelos (Mexico)

    2012-09-15

    Climate change and resultant coastal erosion and flooding have been the focus of many recent analyses. Often these studies overlook the effects of manmade modifications to the coastline which have reduced its resilience to storm events. In this investigation, we integrate previous reports, historical photo analysis, field work, and the application of numerical models to better understand the effects of Wilma, the most destructive hurricane to affect Cancun, Mexico. Huge waves (of significant height, >12 m), long mean wave periods (>12 s), devastating winds (>250 km/h), and powerful currents (>2 m/s) removed >7 million cubic meters of sand from the Cancun beach system, leaving 68% of the sub-aerial beach as bedrock, and the rest considerably eroded. Numerical simulations show that the modifications to the barrier island imposed by tourist infrastructure have considerably increased the rigidity of the system, increasing the potential erosion of the beach under extreme conditions. If there were no structural barriers, a series of breaches could occur along the beach, allowing exchange of water and alleviating storm surge on other sections of the beach. If the effects caused by anthropogenic changes to Cancun are ignored, the analysis is inaccurate and misleading. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Influence green sand system by core sand additions

    Directory of Open Access Journals (Sweden)

    N. Špirutová

    2012-01-01

    Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

  14. The Effect of the Kind of Sands and Additions on the Mechanical Behaviour of S.C.C

    Science.gov (United States)

    Zeghichi, L.; Benghazi, Z.; Baali, L.

    The sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that investigated the influence of sand quality on the properties of fresh and hardened self-compacting concrete (SCC). The dune sands are very fine materials characterized by a high intergranular porosity, high surface area and low fineness modulus; on the other hand crushed (manufactured) sand has a high rate into thin and irregular shapes which are influencing the workability of concrete. The amount of dune sand varies from (0% 50%, to 100%) by weight of fine aggregates. The effect of additions is also treated (blast furnace slag and lime stone) The results show that the rheological properties favour the use of dune sands; however the mechanical properties support the use of crushed sand.

  15. Dark grains of sand: a geological storytelling

    Science.gov (United States)

    Gallo Maresca, Magda

    2017-04-01

    In the secondary Italian school the Earth science learning begins at first year, in synergy with other natural science subjects such as Astronomy, Chemistry and Biology. Italian teachers have to focus on the landscape geomorphological aspects and often Earth processes are difficult to display since they are related to certain phenomena happened during the past and often far from the involved country. In order to better understand the environment surrounding us, very simple and poor materials, like sands, allow the teachers to create attractive lab experiences. According to the IBSE (Inquiry Based Science Education) approach, a learning unit has been implemented starting from a walking along the light carbonate beaches of the Adriatic sea: a smart look to the sands ("engage step"), stroke the students fantasy pushing them to explore some strange black grains on the sands. Dirty sands? Or rock landscape, soil degradation and Ofanto river and coastal processes (erosion, transportation and deposition)? This was the teaching challenge. Due to the youngest age, a third level, guided inquiry, was adopted so the teacher is the "guide of inquiry" encouraging the students using the research question ("Why is the sand dark?", "Do all sands look the same?", "Where does it come from?") and driving the students around their investigation plans ("How can I measure grain size?"). A procedure to answer the above questions and validate the results and explanations has been implemented to allow the students to be proactive in their study. During the learning activities will be the students to ask for field trip to elaborate their new knowledge, verify and visualize the speculated processes. The teaching skills allow to address several geosciences domains such as mineralogy, petrology, regional geology and geodynamics as well as other scientific disciplines such as mathematics (more specifically statistics), forensic science and even life sciences (the presence of bioclasts might

  16. Searching a Holocene coastal lagoon for paleotsunami deposits: Kamala Beach, Phuket, Thailand

    Science.gov (United States)

    Schmidt, J. R.; Kirby, M. E.; Rhodes, B. P.; Jankaew, K.

    2006-12-01

    In the wake of the devastating December 26, 2004 Indian Ocean tsunami, there is a renewed effort to locate and date paleotsunami deposits. As part of this effort, one piston and two push cores were extracted along a transect from a Holocene age coastal lagoon in Kamala Beach, Phuket, Thailand. The piston core (KBPISTON06-1 measures 513 cm total length. The overall sedimentology reflects a long-term sea level regression and beach progradation across the core site to the modern beach position. The sedimentology is, however, highly complex indicating variable depositional environments throughout the Holocene. Basal sands (estimated at 8,000 cy BP) are overlain by various thickness laminated clays, interbedded organic silts, and occasional sands. The upper 40 cm may reflect recent human disturbance, which includes mining of placer tin, planting of coconut trees, and tourist-related infrastructure. In addition to visual descriptions, mass magnetic susceptibility, percent total organic matter, and percent total carbonate were determined at 1 cm contiguous intervals. Micro-fossil counts and grain size measurements were also determined but at lower resolution throughout the core. Using visual description as the basic identifying criteria, we recognize four candidate deposits as potentially tsunamigenic. Each of the four units is sand-rich. Sandy clays bracket the upper two sand units; whereas, the lower two sand units are much coarser and bracketed by semi-to-well laminated clays. Considering each of the analyses above, we cannot identify any one of these candidate deposits as unequivocally tsunamigenic. Similarly, we cannot conclude that any one of these candidate deposits is not tsunamigenic. Nonetheless, our initial conclusion is that coastal lagoon environments may not represent the best location for preservation and identification of paleotsunami deposits in Thailand. Sites with less complex terrestrial-marine sediment interaction, such mangrove swamps, may be easier

  17. Cleaning oil sands drilling waste in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Mikic, N.; Nilsen, C.; Markabi, M. [Mi SWACO, Calgary, AB (Canada)

    2008-07-01

    The waste generated from steam assisted gravity drainage (SAGD) wells is brought to the surface and separated by shale shakers. The waste can include drilling fluids and sand contaminated with bitumen. This paper described a new technology developed to treat waste using the addition of hot water and various mixing and separation technologies to reduce the viscosity of the bitumen and separate it from the sand. The bitumen-contaminated drill cuttings were mixed with hot water to form a slurry that was then separated through the G-force created by a hydrocyclone. A secondary separation was then conducted in an elutriation column to remove residual contaminants from the sand. The flow rate of the process was controlled by the fine solids composition of the cuttings, the temperature of the cleaning process, and the performance of the individual components. Laboratory tests conducted to tests the method showed that the sand particles produced using the method were clean enough to be safely disposed in the environment. A pilot study will be conducted to test the sand cleaning technology at a commercial scale. 6 refs., 3 figs.

  18. Aeolian sediment transport on a beach: Thresholds, intermittency, and high frequency variability

    Science.gov (United States)

    Davidson-Arnott, R. G. D.; Bauer, B. O.

    2009-04-01

    During a field experiment designed to measure wind flow and sediment transport over the beach and foredune at Greenwich Dunes, Prince Edward Island National Park, measurements were made on October 11, 2004, during a storm with wind speeds ranging from 4 ms - 1 to over 20 ms - 1 . This paper examines thresholds of sand movement, intermittency and the relationship between fluctuating winds and transport intensity based on high frequency measurements of wind speed and saltation. Wind speed was measured at four points across the beach profile using cup anemometers set at a height of 0.6 m. The anemometers were co-located with saltation probes (set at a height of 0.02 m) that measure the impacts of saltating sand grains. The instruments were sampled at 1 Hz during runs of 1 or 2 h over an eight-hour period. Sand transport was highly intermittent early in the day when winds were only slightly above threshold and became more continuous towards the upper beach because of increasing fetch distance and decreasing surface moisture. Despite more continuous transport and increasing wind speed through the day, a zone of highly intermittent transport migrated landward across the beach as water levels rose due to storm surge. Examination of three thresholds related to measures of wind speed - the maximum wind speed without transport ( Utmax), minimum wind speed with transport ( Utmin) and the intermittency threshold ( Utγ) - showed that none provide a consistently robust measure of the threshold although they all provide some insight into conditions controlling entrainment. While graphs of instantaneous saltation intensity crudely mimic the pattern of fluctuating wind speed, statistical correlations over periods of 2-10 min were generally poor ( R2 < 0.25) even with considerable smoothing applied to the time series. Such poor correlation appears to reflect the spatial and temporal complexity of the beach surface, particularly the pattern of surface moisture as well as saltation

  19. Sands cykliske styrke

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    1992-01-01

    Sands cykliske styrke kan beskrives ved Cyclic Liquefaction, Mobilisering, Stabilization og Instant Stabilization. I artiklen beskrives hvorfor Stabilization og Instant Stabilization ikke observeres, når sands udrænede styrke undersøges i triaxial celler, der anvender prøver med dobbelt prøvehøjde....

  20. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Bødker, Lars Bødker

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...

  1. Dosimetry evaluation of the potential exposure bound to uranium and thorium natural accumulation in the sand of some beaches of the Camargue littoral; Evaluations dosimetriques de l'exposition potentielle liee a l'accumulation naturelle d'uranium et de thorium dans les sables de certaines plages du littoral de Camargue

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The aim of this report is the assessment of potential exposure to radioactive sands discovered in 2000 in two points of the coast of the Camargue (East of Beauduc and Espiguette lighthouses), where specific activity can reach up several thousands of Bq.kg{sup -1} for radionuclides of U{sup 238} and Th{sup 232} radioactive families, and environmental dose rate up to ten times of usual natural background. The excess of radioactivity is carried by small particles of sand (apatites and zircons less than 100 {mu}m). First chapter focuses on radioactivity of the coast of the Golfe du lion and of the Camargue, and more particularly on these two points (cartography, measure, radionuclide identification, mineralogical characterization of particles). This chapter concludes the excess of radioactivity is natural; particles come from several massifs of the Rhone basin, transported by the river and re-distributed on the coast. Second chapter focuses on dosimetric assessment, using reasonable scenarios for the frequenting of these sites by persons of the public in one hand, and drawing up the sizing of the sands and their solubility in gastric and intestinal fluids in an other hand. the annual effective dose, carefully calculated, is about 1 mSv, mainly due to external exposure to gamma rays. such a dose, of same levels as the dose received for 17 months of residence in Paris for example, does not involve any particular action. (authors)

  2. Sea-cliff erosion as a function of beach changes and extreme wave runup during the 1997-1998 El Nino

    Science.gov (United States)

    Sallenger, A.H.; Krabill, W.; Brock, J.; Swift, R.; Manizade, S.; Stockdon, H.

    2002-01-01

    Over time scales of hundreds to thousands of years, the net longshore sand transport direction along the central California coast has been driven to the south by North Pacific winter swell. In contrast, during the El Nin??o winter of 1997-1998, comparisons of before and after airborne lidar surveys showed sand was transported from south to north and accumulated on the south sides of resistant headlands bordering pocket beaches. This resulted in significant beach erosion at the south ends of pocket beaches and deposition in the north ends. Coincident with the south-to-north redistribution of sand, shoreline morphology became prominently cuspate with longshore wavelengths of 400-700 m. The width and elevation of beaches were least where maximum shoreline erosion occurred, preferentially exposing cliffs to wave attack. The resulting erosional hotspots typically were located in the embayments of giant cusps in the southern end of the pocket beaches. The observed magnitude of sea cliff retreat, which reached 14 m, varied with the number of hours that extreme wave runup exceeded certain thresholds representing the protective capacity of the beach during the El Nin??o winter. A threshold representing the width of the beach performed better than a threshold representing the elevation of the beach. The magnitude of cliff erosion can be scaled using a simple model based on the cross-shore distance that extreme wave runup exceeded the pre-winter cliff position. Cliff erosion appears to be a balance between terrestrial mass wasting processes, which tend to decrease the cliff slope, and wave attack, which removes debris and erodes the cliff base increasing the cliff slope. ?? 2002 Elsevier Science B.V. All rights reserved.

  3. 鄂尔多斯盆地南部延7+8油层组滨浅湖滩坝体系沉积特征%Sedimentary characteristics of the shore-shallow lacustrine beach bar system of Yan 7+8 oil reservoirs in southern Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    王建民

    2013-01-01

    Retrograding sedimentary sequence and shore-shallow lacustrine beach bar system are developed in the Meso-zoic Jurassic Yan ’ an Formation in southern Ordos Basin ,and the latter has close paragenetic relationship with the mean-dering river delta around the lake basin of the Yan ’ an stage .Retrogradation and the destruction of the meandering delta provide clastic input for the development of the low-shallow lake beach bar system .During the depostion of Yan 7+8, An’ sai and Zhidan areas in the north of Shaaxi province were in shore-shallow lacustrine environment .Beach bar deposits were widely developed as the major part of sedimentation ,and can be divided into four microfacies types including beach sand,sand bar,sand sheet and mudstone .Generally,the beach bar sand bodies occur at the side of the river mouth and the flat open shore-shallow lake environment ,and are parallel with the lake shoreline .They are dominated by medium and fine sandstone,and have massive bedding ,wavy bedding,inclined wavy bedding and lenticular bedding ,etc.Beach sand is usually in sheet-like shape and is relatively thin.Bar sand,which is the most representative deposit of the beach bar system ,usually has banded shoreline-parallel distribution ,large thickness ,and lenticular shape on section ,reverse grading at the bottom and transgressive sequences in the middle and upper parts .A series of beach bar sandbodies superimposed with each other in different phases ,forming large-scale shoreline-parallel clustered reservoirs with high net-to-gross ratio . The mudstones of shore-shallow lake facies between the beach bars act as lateral barriers or overlying seals of the beach bar sandbodies .The sedimentary characteristics of the shore-shallow lacustrine beach bar system have significant influ-ences on reservoir development and oil/gas accumulation of the Yan ’ an Formation.%鄂南中生界侏罗系延安组发育退积型沉积层序及滨浅湖滩坝沉积体系;滨浅湖滩坝

  4. Citizen Science: Dune Restoration with Sea Oats by Junior Friends of MacArthur Beach State Park

    Science.gov (United States)

    Allen, S.

    2016-12-01

    As a crucial part of the dune ecosystem, Sea Oats are a protected species in Florida. They provide excellent habitat for small birds and mammals and prevent dune erosion with their fibrous roots.Citizen science is a research and education tool that involves everyday people in real and meaningful forms of science. My volunteer group, Junior friends of Macarthur Beach State Park, used citizen science to restore dunes by growing and planting Sea Oats. Junior friends is a group of 6-12th grade students whose purpose is to support the park through monthly activities and special events. Junior Friends asked,what is the best way to germinate/grow/and plant Sea Oats to renourish the beach dune. Specifically, what planting medium is most conducive for maximizing growth of Sea Oats? We tested three scenarios: 100% potting soil, 100% sand from the beach, 50% sand-50% potting soil mixture.Using harvested Sea Oat seeds from Macarthur Beach State Park, we separated the seeds from their casings, known as spiklets. We then monitored the plant's weekly over the course of 14 weeks and charted their growth. All the seeds had similar growth rates, but the seeds that grew in 100% potting soil consistently grew the tallest. The second tallest Sea Oats were 100% sand; the 50% sand-50% potting soil mixture produced the least amount of growth. When seedlings reached their desired growth of 6-8 inches and established a root ball, we planted the Sea Oats on the dune for restoration. After planting them,we monitored the growth of the Sea Oats on the MacArthur Beach dune throughout the rest of the year, charting the height of the planted Sea Oats. Using Citizen science we had meaningful data that helped us have a better understanding of restoring Sea Oats on Florida dunes and will help further future restorations.

  5. Coastal geology and recent origins for Sand Point, Lake Superior

    Science.gov (United States)

    Fisher, Timothy G.; Krantz, David E.; Castaneda, Mario R.; Loope, Walter L.; Jol, Harry M.; Goble, Ronald J.; Higley, Melinda C.; DeWald, Samantha; Hansen, Paul

    2014-01-01

    Sand Point is a small cuspate foreland located along the southeastern shore of Lake Superior within Pictured Rocks National Lakeshore near Munising, Michigan. Park managers’ concerns for the integrity of historic buildings at the northern periphery of the point during the rising lake levels in the mid-1980s greatly elevated the priority of research into the geomorphic history and age of Sand Point. To pursue this priority, we recovered sediment cores from four ponds on Sand Point, assessed subsurface stratigraphy onshore and offshore using geophysical techniques, and interpreted the chronology of events using radiocarbon and luminescence dating. Sand Point formed at the southwest edge of a subaqueous platform whose base is probably constructed of glacial diamicton and outwash. During the post-glacial Nipissing Transgression, the base was mantled with sand derived from erosion of adjacent sandstone cliffs. An aerial photograph time sequence, 1939–present, shows that the periphery of the platform has evolved considerably during historical time, infl uenced by transport of sediment into adjacent South Bay. Shallow seismic refl ections suggest slump blocks along the leading edge of the platform. Light detection and ranging (LiDAR) and shallow seismic refl ections to the northwest of the platform reveal large sand waves within a deep (12 m) channel produced by currents fl owing episodically to the northeast into Lake Superior. Ground-penetrating radar profi les show transport and deposition of sand across the upper surface of the platform. Basal radiocarbon dates from ponds between subaerial beach ridges range in age from 540 to 910 cal yr B.P., suggesting that Sand Point became emergent during the last ~1000 years, upon the separation of Lake Superior from Lakes Huron and Michigan. However, optically stimulated luminescence (OSL) ages from the beach ridges were two to three times as old as the radiocarbon ages, implying that emergence of Sand Point may have begun

  6. Ground-water geology of the coastal zone, Long Beach-Santa Ana area, California

    Science.gov (United States)

    Poland, J.F.; Piper, A.M.

    1956-01-01

    structural features that influence the watertightness of the so-called coastal barrier. The hills and mesas of the Newport-Inglewood belt are cut by six gaps through which tongues of the central lowland extend to the coast. The gaps are trenched in the deformed late Pleistocene surface and are floored with alluvium that is highly permeable in its lower part. The Long Beach-Santa Ana area, with which this report is concerned, encompasses the central and eastern segments of the coastal plain, and includes five of the gaps in succession from northwest to south- east: Dominguez, Alamitos, Sunset, Bolsa, and Santa Ana Gaps. In the Long Beach-Santa Ana area a thick sequence of Quaternary and Tertiary sedimentary rocks has been deposited on a basement of metamorphic and crystalline rocks of pre-Tertiary age. In the broad syncline underlying tl e central part of Downey Plain these sediments probably exceed 20,000 feet in thickness. This report pertains chiefly to the geology and water-bearing character of the rocks that underlie the coastal zone of the Long Beach-Santa Ana area. This area extends some 27 miles from Dominguez Hill on the northwest to Newport Beach on the southeast, has an average width of about 6 miles, includes some 180 square miles, and borders the Pacific Ocean. Of the Quaternary deposits the youngest are of Recent age and comprise silt, sand, gravel, and clay, chiefly of fluvial origin; they are the latest contributions to the alluvial cones of the Los Angeles, San Gabriel, and Santa Ana Rivers; their thickness is as much as 175 feet. The upper division of the Recent deposits, largely fine sand and silt of low permeability, commonly furnishes water only to a few wells of small yield; the lower division is coarse sand and gravel deposited chiefly in two tongues extending respectively, from Whittier Narrows through Dominguez Gap and from Santa Ana Canyon through Santa Ana Gap. These tongues, designated in this report the Gaspur a

  7. Towards improved prediction and mitigation of beach overwash: Terrestrial LiDAR observation of dynamic beach berm erosion

    Science.gov (United States)

    Schubert, J. E.; Gallien, T.; Shakeri Majd, M.; Sanders, B. F.

    2012-12-01

    Globally, over 20 million people currently reside below high tide levels and 200 million are below storm tide levels. Future climate change along with the pressures of urbanization will exacerbate flooding in low lying coastal communities. In Southern California, coastal flooding is triggered by a combination of high tides, storm surge, and waves and recent research suggests that a current 100 year flood event may be experienced on a yearly basis by 2050 due to sea level rise adding a positive offset to return levels. Currently, Southern California coastal communities mitigate the threat of beach overwash, and consequent backshore flooding, with a combination of planning and operational activities such as protective beach berm construction. Theses berms consist of temporary alongshore sand dunes constructed days or hours before an extreme tide or wave event. Hydraulic modeling in urbanized embayments has shown that coastal flooding predictions are extremely sensitive to the presence of coastal protective infrastructure, requiring parameterization of the hard infrastructure elevations at centimetric accuracy. Beach berms are an example of temporary dynamic structures which undergo severe erosion during extreme events and are typically not included in flood risk assessment. Currently, little is known about the erosion process and performance of these structures, which adds uncertainty to flood hazard delineation and flood forecasts. To develop a deeper understanding of beach berm erosion dynamics, three trapezoidal shaped berms, approximately 35 m long and 1.5 m high, were constructed and failure during rising tide conditions was observed using terrestrial laser scanning. Concurrently, real-time kinematic GPS, high-definition time lapse photography, a local tide gauge and wave climate data were collected. The result is a rich and unique observational dataset capturing berm erosion dynamics. This poster highlights the data collected and presents methods for processing

  8. The response and recovery of coastal beach-dune systems to storms

    Science.gov (United States)

    Farrell, Eugene; Lynch, Kevin; Wilkes Orozco, Sinead; Castro Camba, Guillermo

    2017-04-01

    This two year field monitoring project examines the response and recovery of a coastal beach-dune system in the west coast of Ireland (The Maharees, Co. Kerry) to storms. Historic analyses were completed using maps, aerial photography, and DGPS surveys with the Digital Shoreline Analysis System. The results establish that the average shoreline recession along the 1.2 km site is 72 m during the past 115 years. The coastal monitoring experiment aims to link micro-scale aeolian processes and meso-scale beach-dune behaviour to identify and quantify sediment exchange between the beach and dune under different meteorological and hydrodynamic conditions. Geomorphological changes on the beach and near-shore bar migration were monitored using repeated monthly DGPS surveys and drone technology. Topographical data were correlated with atmospheric data obtained from a locally installed Campbell Scientific automatic weather station, oceanographic data from secondary sources, and photogrammetry using a camera installed at the site collecting pictures every 10 minutes during daylight hours. Changes in surface elevation on the top of the foredune caused by aeolian processes are measured using erosion pin transects. The preliminary results illustrate that natural beach building processes initiate system recovery post storms including elevated foreshores and backshores and nearshore sand bar migration across the entire 1.2 km stretch of coastline. In parallel with the scientific work, the local community have mobilized and are working closely with the lead scientists to implement short term coastal management strategies such as signage, information booklets, sand trap fencing, walkways, wooden revetments, dune planting in order to support the end goal of obtaining financial support from government for a larger, long term coastal protection plan.

  9. Low level off-road vehicle (ORV) traffic negatively impacts macroinvertebrate assemblages at sandy beaches in south-western Australia.

    Science.gov (United States)

    Davies, Rebecca; Speldewinde, Peter C; Stewart, Barbara A

    2016-04-28

    Off-road vehicle use is arguably one of the most environmentally damaging human activities undertaken on sandy beaches worldwide. Existing studies focused on areas of high traffic volumes have demonstrated significantly lower abundance, diversity and species richness of fauna in zones where traffic is concentrated. The impact of lower traffic volumes is unknown. This study aimed to investigate the impacts of relatively low-level vehicle traffic on sandy beach fauna by sampling invertebrate communities at eight beaches located in south-western Australia. We found that even low-level vehicle traffic negatively impacts the physical beach environment, and consequently, the ability of many species to survive in this habitat in the face of this disturbance. Compaction, rutting and displacement of the sand matrix were observed over a large area, resulting in significant decreases in species diversity and density, and measurable shifts in community structure on beaches that experienced off-road vehicle traffic. Communities at impact sites did not display seasonal recovery as traffic was not significantly different between seasons. Given a choice between either reducing traffic volumes, or excluding ORV traffic from beaches, our results suggest that the latter would be more appropriate when the retention of ecological integrity is the objective.

  10. Case study Piçarras Beach: Erosion and nourishment of a headland bay beach

    NARCIS (Netherlands)

    Van den Heuvel, S.; Hoekstra, R.; De Zeeuw, R.; Zoon, A.

    2008-01-01

    Master project report. Piçarras is one of the touristic beaches of Santa Catarina state in Brazil. Piçarras beach is a headland bay beach. In the bay irregular features like an island, rocky outcrops and shoals are present influencing wave propagation. In the south Piçarras is bounded by Piçarras ri

  11. 77 FR 27120 - Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA

    Science.gov (United States)

    2012-05-09

    ..., Virginia Beach, VA in the Federal Register (76 FR 13519). We received one comment on the proposed rule. No... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY:...

  12. Physical processes and landforms on beaches in short fetch environments in estuaries, small lakes and reservoirs: A review

    Science.gov (United States)

    Nordstrom, Karl F.; Jackson, Nancy L.

    2012-02-01

    This review is intended to identify differences between beaches in short-fetch environments and beaches on exposed coasts, while also distinguishing between the different subcategories of fetch-limited beaches. Subcategories are discussed largely in terms of estuaries, lakes and reservoirs. The term fetch-limited refers to basins that are small enough that distance rather than wind duration is always a limitation to wave generation. Attention is focused on basins where fetch distances are wind-induced currents, tidal currents and ice to be relatively more effective than on exposed beaches. Shoreline orientations differ greatly over short distances, causing great differences in exposure to dominant winds and isolating beach segments. Limited longshore sediment exchanges result in beach sediments that closely resemble local source materials. The absence of high-energy waves causes beaches and bar forms to be smaller, and the absence of swell waves following storms and the relatively calm conditions reduces the speed of recovery of post-storm profiles and the cyclic nature of beach response. The beaches are often fronted by flat shallow platforms that undergo little morphologic change and help dissipate waves at low water levels. The narrow beaches are poor sources of sediment for wind-blown sand and dunes are small or frequently absent. The narrow beaches and reduced wave energies allow upland vegetation and algae and seagrass to grow close to the active foreshore. This vegetation, the wrack deposited on the beach, and driftwood logs are better able to resist the low-energy waves and are more effective in resisting beach change. Erosion rates of 2-3 m yr- 1 are common in some estuaries and can be > 7 m yr- 1. Rates of up to 1.5 m yr- 1 can occur in small lakes and reservoirs. Shore parallel protection structures are common and have greater survivability in low-energy environments than high-energy environments; they are cheaper to build; and they have been implemented

  13. Microplastic concentrations in beach sediments along the German Baltic coast.

    Science.gov (United States)

    Stolte, Andrea; Forster, Stefan; Gerdts, Gunnar; Schubert, Hendrik

    2015-10-15

    The contamination with microplastic particles and fibres was evaluated on beaches along the German Baltic coast. Sediments were sampled near the Warnow and Oder/Peene estuaries, on Rügen island and along the Rostock coast to derive possible entry pathways. Seasonal variations were monitored along the Rostock coast from March to July 2014. After density separation in saline solution, floating particles were found to be dominated by sand grains. Water surface tension is shown to be sufficient to explain floatation of grains with sizes less than 1.5mm. Selecting intensely coloured particles and fibres, we find lower limits of the microplastic concentrations of 0-7 particles/kg and 2-11 fibres/kg dry sediment. The largest microplastic contaminations are measured at the Peene outlet into the Baltic Sea and in the North Sea Jade Bay. City discharges, industrial production sites, fishing activity and tourism are the most likely sources for the highest microplastic concentrations.

  14. Holocene marine transgression as interpreted from bathymetry and sand grain size parameters off Gopalpur

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, K.M.; Rajamanickam, G.V.; Rao, T.C.S.

    Grain size statistical parameters of the surface sediment samples collected from the innershelf off Gopalpur were calculated using graphic and moment methods. Fine-grained sand present up to 15 m water depth shows symmetrical skewness and good...

  15. 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...

  16. Intensified coastal development in beach-nourishment zones

    Science.gov (United States)

    Lazarus, E.; Armstrong, S.; Limber, P. W.; Goldstein, E. B.; Ballinger, R.

    2016-12-01

    Population density, housing development, and property values in coastal counties along the U.S. Atlantic and Gulf Coasts continue to rise despite increasing hazard from storm impacts. Beach nourishment, a method for mitigating coastal storm damage or chronic erosion by deliberately replacing sand on an eroded beach, has been the leading form of coastal protection in the U.S. since the 1970s. However, investment in hazard protection can have the unintended consequence of encouraging development in places especially vulnerable to damage. To quantitatively compare development in nourishing and non-nourishing zones, we examine the parcel-scale housing stock of all shorefront single-family homes in the state of Florida. We find that houses in nourishing zones are significantly larger and more numerous than in non-nourishing zones. Florida represents both an advanced case of coastal risk and an exemplar of ubiquitous, fundamental challenges in coastal management. The predominance of larger homes in nourishing zones indicates a positive feedback between nourishment and development that is compounding coastal risk in zones already characterized by high vulnerability. We offer that this phenomenon represents a variant of Jevons' paradox, a theoretical argument from environmental economics in which more efficient use of a resource spurs an increase in its consumption. Here, we suggest reductions in coastal risk through hazard protection are ultimately offset or reversed by increased coastal development.

  17. Contribution of sand-associated enterococci to dry weather water quality.

    Science.gov (United States)

    Halliday, Elizabeth; Ralston, David K; Gast, Rebecca J

    2015-01-06

    Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from mean ENT in water could be predicted by a linear regression with turbidity alone. Temperature was also positively correlated with ENT abundance in this study, which may indicate an important role of seasonal warming in temperate regions. Inundation by spring tides was the primary rewetting mechanism that sustained culturable enterococci populations in high-tide sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions.

  18. Recycled sand in lime-based mortars.

    Science.gov (United States)

    Stefanidou, M; Anastasiou, E; Georgiadis Filikas, K

    2014-12-01

    The increasing awareness of the society about safe guarding heritage buildings and at the same time protecting the environment promotes strategies of combining principles of restoration with environmentally friendly materials and techniques. Along these lines, an experimental program was carried out in order to investigate the possibility of producing repair, lime-based mortars used in historic buildings incorporating secondary materials. The alternative material tested was recycled fine aggregates originating from mixed construction and demolition waste. Extensive tests on the raw materials have been performed and mortar mixtures were produced using different binding systems with natural, standard and recycled sand in order to compare their mechanical, physical and microstructure properties. The study reveals the improved behavior of lime mortars, even at early ages, due to the reaction of lime with the Al and Si constituents of the fine recycled sand. The role of the recycled sand was more beneficial in lime mortars rather than the lime-pozzolan or lime-pozzolan-cement mortars as a decrease in their performance was recorded in the latter cases due to the mortars' structure.

  19. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described...... in the succeeding sections. Finally the test results are briefly summarised and a relationship between void ratio l and permeability is established....

  20. Sand and Gravel Deposits

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is a statewide polygon coverage of sand, gravel, and stone resources. This database includes the best data available from the VT Agency of Natural...

  1. Sand and Gravel Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes sand and gravel operations in the United States. These data were obtained from information reported voluntarily to the USGS by the aggregate...

  2. 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

  3. Morphology, grain-size and faunistic composition of the macrotidal beaches of Tierra del Fuego Morfología, tamaño de grano y composición faunística de las playas macromareales de Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    F.I. Isla

    2005-09-01

    Full Text Available Morphodynamic models have been applied to macrotidal beaches. They are based on unimodal grain sizes and average dynamic parameters as the wave height and period at the breaker zone. Bimodal gravel beaches do not fit to these models because a grain size is subject to spatial segregations (gravel and granules at the upper beach zones and fine sand at the lower-tide terrace, and b wave dynamics vary temporarily during the tidal cycle: the beach has a reflective behaviour during high tide and dissipative during low tide. Superimposed to these morphodynamical constraints, along the Atlantic coast of Tierra del Fuego inherited factors control the coastal morphology. In low-lying coasts (South-American Plate portion, the Holocene sea-level fluctuation permitted the construction of beach ridge plains. On high-relief coasts (Scotia Microplate, the same fluctuation have little enough sediment available, and therefore pocket beaches developed between capes and sand accumulations at river outlets. Two areas were found of interest by their heavy mineral content: the Rio Chico beach-ridge plain, and the coastline between Ewan and Ladrillero estuaries. With regard to the molluscan beach composition, rocky bottom specimens dominate at the capes.Los modelos morfodinámicos han sido aplicados a playas macromareales basados en granulometrías unimodales y parámetros dinámicos estables como la altura de ola y período estimados en la rompiente. Las playas bimodales de grava no se consideran en estos modelos debido a que las granulometrías están sujetas a segregaciones espaciales (gravas y gránulos en los sectores superiores de la playa, y arena fina en los sectores inferiores y variaciones temporales en la dinámica de las olas condicionadas por la marea (la playa tiene una dinámica reflectiva durante marea alta y disipativa durante marea baja. Sobreimpuestos a estas limitaciones morfodinámicas, en la costa atlántica de Tierra del Fuego se dan factores

  4. Vestled - Hvide Sande

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten; Hesselbjerg, Marianne; Schønherr, Torben

    2009-01-01

    Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side......Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side...

  5. High-speed X-ray imaging of a ball impacting on loose sand

    NARCIS (Netherlands)

    Homan, T.A.M.; Mudde, R.F.; Lohse, Detlef; van der Meer, Roger M.

    2015-01-01

    When a ball is dropped in fine very loose sand, a splash and subsequently a jet are observed above the bed, followed by a granular eruption. To directly and quantitatively determine what happens inside the sand bed, high-speed X-ray tomography measurements are carried out in a custom-made set-up

  6. Mechanical properties of sand modified resins used for bonding CFRP to concrete substrates

    Directory of Open Access Journals (Sweden)

    Aziz. I. Abdulla

    2016-12-01

    Full Text Available This study is an experimental investigation into the properties of adhesive before and after mixing with fine sand, and its behavior on reinforced concrete beams strengthened by CFRP to show the effects of modified adhesive on load-carrying capacity, ductility, stiffness and failure mode of the reinforced concrete beams. Compressive strength, flexural strength and the effect of high temperature on these properties were the focus of the current study in order to prove the efficiency of adding fine sand to improve adhesive properties and reduce cost. Based on the compressive and flexural tests, results indicated that the addition of sand to the adhesive improved its mechanical properties when sand is 50% of the total weight of the adhesive. However, its effect on the modulus of elasticity is minimal. Using adhesive with fine sand increased the ultimate load bearing capacity, ductility, stiffness and toughness of the reinforced concrete beams strengthened by CFRP. The ratio of the fine sand to the adhesive equal to 1 is considered the best in terms of the cost reduction, maintaining workability, as well as maintaining the mechanical properties. Lastly, the use of fine sand with adhesive ensured a significant reduction in the cost of the adhesive and increased the adhesive resistance to temperature.

  7. Dynamic response of dry and water-saturated sand systems

    Science.gov (United States)

    LaJeunesse, J. W.; Hankin, M.; Kennedy, G. B.; Spaulding, D. K.; Schumaker, M. G.; Neel, C. H.; Borg, J. P.; Stewart, S. T.; Thadhani, N. N.

    2017-07-01

    The effect of grain size and moisture content on the dynamic macroscopic response of granular geological materials was explored by performing uniaxial planar impact experiments on high purity, Oklahoma #1, sand samples composed of either fine (75-150 μm) or coarse (425-500 μm) grain sizes in either dry or fully water-saturated conditions. Oklahoma #1 sand was chosen for its smooth, quasi-spherical grain shapes, narrow grain size distributions, and nearly pure SiO2 composition (99.8 wt. %). The water-saturated samples were completely saturated ensuring a two-phase mixture with roughly 65% sand and 35% water. Sand samples were dynamically loaded to pressures between 1 and 11 GPa. Three-dimensional meso-scale simulations using an Eulerian hydrocode, CTH, were created to model the response of each sand sample. Multi-phase equations of state were used for both silicon dioxide, which comprised individual sand grains, and water, which surrounded individual grains. Particle velocity profiles measured from the rear surface of the sand, both experimentally and computationally, reveal that fine grain samples have steeper rise characteristics than coarse grain samples and water-saturated samples have an overall much stiffer response than dry samples. The experimentally determined particle velocity vs. shock velocity response of dry sand was linear over this pressure range, with little difference between the two grain sizes investigated. The experimental response for the water saturated sand exhibited a piecewise continuous response with a transition region between particle velocities of 0.6 km s-1 and 0.8 km s-1 and a pressure of 4.5-6 GPa. Hypotheses for the cause of this transition region are drawn based on results of the meso-scale simulations.

  8. Longshore Sediment Transport on a Macrotidal Mixed Sediment Beach, Birling Gap, United Kingdom.

    Science.gov (United States)

    Curoy, J.; Moses, C. A.; Robinson, D. A.

    2012-04-01

    Mixed beaches (MBs), with sediment sizes ranging over three orders of magnitude, are an increasingly important coastal defence on > 1/3 of the shoreline of England and Wales. In East Sussex, the combined effect of coastal defence management schemes (extensive groyning and sea wall construction) has reduced beach sediment supply. Local authorities counteract the increased flood risk by recycling or artificially recharging beaches on the most vulnerable and populated areas. Beaches lose sediment predominantly via longshore transport (LST) whose accurate quantification is critical to calculating recharge amounts needed for effective beach management. Industry does this by using sediment transport modelling which depends on reliable input data and modelling assumptions. To improve understanding of processes and quantification of LST on MBs, this study has accurately measured sediment transport on a natural, macrotidal, MB. The 1.2 km natural MB at Birling Gap, East Sussex here is located on the downdrift end of an 80 km long sub-sedimentary cell and is oriented WNW-ESE. The beach lies on a low gradient chalk shore platform backed by sub-vertical chalk cliffs. It is composed primarily of flint gravel with a peak grain size distribution of 30 to 50 mm, and a sand content of up to 30%. Sediment transport was measured using pebble tracers and GPS surface surveys during three survey periods of three to five consecutive days in March, May and December 2006. Tracer pebbles, matching the beach pebbles' D50, were made of an epoxy resin with a copper core allowing their detection and recovery to a depth of 40 cm using a metal detector. Tracers were deployed on the upper, middle and lower beach, from the surface into the beach to depths of up to 40 cm. They were collected on the low tide following deployment. The wave conditions were recorded on a Valeport DWR wave recorder located seaward of the beach on the chalk platform. Over the three study periods a large spectrum of wave

  9. MECHANICAL REGENERATION OF SAND WASTE

    Directory of Open Access Journals (Sweden)

    D. I. Gnir

    2005-01-01

    Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

  10. Close-range airborne Structure-from-Motion Photogrammetry for high-resolution beach morphometric surveys: Examples from an embayed rotating beach

    Science.gov (United States)

    Brunier, Guillaume; Fleury, Jules; Anthony, Edward J.; Gardel, Antoine; Dussouillez, Philippe

    2016-05-01

    points, we obtained a mean vertical accuracy less than ± 10 cm, with a maximum of 20 cm in marginal sectors with sparse vegetation and in the lower intertidal zone where water-saturated surfaces generated lower-resolution data as a result of a lack of coherence between photographs. The overall results show that SfM photogrammetry is a robust tool for beach morphological and sediment budget surveys. Our SfM workflow enabled the discrimination of beach surface features at a scale of a few tens of centimetres despite the low textural contrasts exhibited by the quartz beach sand and the relatively uniform upper beach topography, as well as the calculation of beach sediment budgets. 66,000 m³ of sand were removed from the northern sector of the beach, of which 22,000 m³ were transferred to the southern sector in the course of rotation. Finally, we briefly highlight: (1) the advantages of SfM photogrammetry compared to other high-resolution survey methods, (2) the advantages and disadvantages of, respectively, a microlight aircraft and an unmanned aerial vehicle (UAV) in undertaking SfM photogrammetry, and (3) areas of potential future improvement of the SfM workflow technique. These concern more extensive cross-shore deployment of ground control points to reduce possible tilt, and oblique cross-shore photography to improve parallax.

  11. Comparison of two Satellite Imaging Platforms for Evaluating Sand Dune Migration in the Ubari Sand Sea (Libyan Fazzan)

    Science.gov (United States)

    Els, A.; Merlo, S.; Knight, J.

    2015-04-01

    Sand dunes can change location, form or dimensions depending on wind direction and strength. Sand dune movements can be effectively monitored through the comparison of multi-temporal satellite images. However, not all remote sensing platforms are suitable to study sand dunes. This study compares coarse (Landsat) and fine (Worldview) resolution platforms, specifically focussing on sand dunes within the Ubari Sand Sea (Libya). Sand dune features (crest line, dune ridge basal outlines) were extracted from Landsat and Worldview 2 imagery in order to construct geomorphic maps. These geomorphic maps were then compared using image overlay and differencing, and the Root Mean Squared Error (RMSE) was used to determine if the mapped dune patterns were significantly different. It was found that Landsat is a sufficient data source when studying dune patterns within a regional sand sea, but smaller dunes identified from Worldview data were not capable of being extracted in the data sourced from Landsat. This means that for studies concerned with the dune patterns and movements within sand seas, Landsat is sufficient. But in studies where the specific dynamics of specific dunes are required, a finer resolution is required; platforms such as Worldview are needed in order to gain more detailed insight and to link the past and present day climate and environmental change.

  12. Metal Enrichment and Toxicity Levels in Sediments from the Tourist Beaches of Southern Durban, South Africa

    Science.gov (United States)

    Chari, S. V.; Vetrimurugan, E.; Jonathan, M. P.; Rodriguez-Espinosa, P. F.

    2014-12-01

    Durban city in South Africa is developing in a fast pace in the field of tourism and thereby needs to be reviewed for the enrichment of metals in tourist beaches. Geochemical studies have been done on nearly 65 beach sediments collected from inter-tidal regions of Amanzi Toti, Isipingo, Bluff, Cutting and southern part of Durban beaches. The study was done in order to unravel the anthropogenic and natural geochemical signals. Total (TTMs) and partially extracted trace metals (PETMs) (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, Zn) in sediments were evaluated along with organic carbon and carbonates. Evaluation of enrichment of geochemical elements were done using contamination factor (CF), pollution load index (PLI), ecological risk index (RI) and geoaccumulation index (Igeo) to understand the pollution status of the study area and it indicates that As, Cd, Cu, Fe, Mn, Ni, Pb, V and Zn are enriched by two to three folds from the natural background values. Uncontrolled tourism activities have led to increase of certain elements in the Durban beaches. Textural analysis provides the information regarding the dominance of sediments either in sand fraction, mud fraction or gravel. The results indicated that they are dominantly coarse grained except in regions where local river input is observed. Industrial development as well as the mining activities in few locations near the coast has led to increase in the elemental concentrations. Regular monitoring of enrichment levels of trace metals in the sediments is mandatory to assess the beach quality in order to restore them from further enrichment so that the biological system in this region is also preserved. Keywords: Tourism, Beach sediments, Trace metals, contamination indices.

  13. Vertical migration of nematodes and soil-borne fungi to developing roots of Ammophila arenaria (L.) link after sand accretion

    NARCIS (Netherlands)

    De Rooij van der Goes, P.C.E.M.; Peters, B.A.M.; Van der Putten, W.H.

    1998-01-01

    Ammophila arenaria benefits from regular burial of windblown beach sand as it allows escape from soilborne pathogens (nematodes and fungi). The present study was done to obtain more insight into the timing and order of migration of the soil organisms towards the newly formed roots. Accordingly,

  14. Managing Fine Sediment in Regulated Rivers

    Science.gov (United States)

    Schmidt, J. C.

    2015-12-01

    A paradigm useful in managing dams and diversions is that the combined effects of changing flow regime and sediment supply perturb regulated rivers into sediment deficit or sediment surplus. In the U.S. Southwest, large dams constructed on interregional rivers typically create sediment deficit segments >100 km long. Further downstream, sediment surplus may occur if desert tributaries deliver sufficient amounts of fine sediment, such as parts of the Rio Grande, lower Green River, and Colorado River delta. Sediment surplus also occurs on most smaller regional rivers. The protocols for managing rivers perturbed into sediment deficit have been refined for the Colorado River downstream from Glen Canyon Dam but are nonetheless challenged by externally determined water-supply agreements that require annual water deliveries that sometimes occur when there has been little tributary resupply. Virtually all of the naturally supplied sand to the depleted, 100-km long Marble Canyon comes from the Paria River. The sand delivery rate since 2012 was sufficiently large to trigger short-duration controlled floods under the High Flow Experiment (HFE) Protocol. The sand mass balance of Marble Canyon since 2012 when the HFE Protocol was adopted was positive due to the combination of relatively large sand delivery from the Paria River and average total annual flows. Large total annual flows have the potential to export large amounts of sand and create a negative sand mass balance. Despite the challenge of managing a scarce and highly variable sand supply and occasional years of large reservoir releases, the long-term (2006-2015) sand mass balance for the upstream half of Marble Canyon is indeterminant and is positive for the downstream half of Marble Canyon. The apparent success of managing sand in Grand Canyon under deficit conditions suggests that fine sediment management protocols might be developed for other regulated rivers. Implementation would require establishment of networks of

  15. Five years of beach drainage survey on a macrotidal beach (Quend-Plage, northern France)

    Science.gov (United States)

    Bain, Olivier; Toulec, Renaud; Combaud, Anne; Villemagne, Guillaume; Barrier, Pascal

    2016-07-01

    A drainage system was installed in 2008 on the macrotidal beach of Quend-Plage, close to Abbeville (Somme, northern France), following a period of significant erosion of recreational areas. The "Direction départementale des territoires et de la mer" (French Coastal Department Authority) has requested a biannual survey in order to validate the beach drainage setup and its efficiency. This paper presents the methodology used for this survey, and the response of the coastal system to this soft engineering method for preventing erosion. These five years of drainage operation have strongly modified the morphology of the beach. Three main modifications occurred: (i) accretion of the upper beach and foredune, (ii) erosion of the lower and middle beach and (iii) a slight shift in directions of the beach bars and troughs. These morphological changes finally led to the stabilization of the beach.

  16. Advanced testing and characterization of transportation soils and bituminous sands

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2007-12-01

    Full Text Available This research study was intended to develop laboratory test procedures for advance testing and characterization of fine-grained cohesive soils and oil sand materials. The test procedures are based on typical field loading conditions and the loading...

  17. Beach Nourishment and Artificial Surf Reef

    NARCIS (Netherlands)

    Klein, A.H.; De Menezes, J.T.; Sperb, R.S.; Siegle, E.; Fontura, R.; Van de Graaff, J.; Stive, M.J.F.; Van der Schrieck, G.L.M.; Verhagen, H.J.

    2004-01-01

    Balneário Camboriú is a very touristy city in southern Brazil, situated in the five kilometer wide Camboriú Bay. Its main tourist attraction is the beach, which is 5800 m long and rather narrow with a dry width of 10 to 20 m. The city is facing several problems regarding the beach that have a

  18. Beach Nourishment and Artificial Surf Reef

    NARCIS (Netherlands)

    Klein, A.H.; De Menezes, J.T.; Sperb, R.S.; Siegle, E.; Fontura, R.; Van de Graaff, J.; Stive, M.J.F.; Van der Schrieck, G.L.M.; Verhagen, H.J.

    2004-01-01

    Balneário Camboriú is a very touristy city in southern Brazil, situated in the five kilometer wide Camboriú Bay. Its main tourist attraction is the beach, which is 5800 m long and rather narrow with a dry width of 10 to 20 m. The city is facing several problems regarding the beach that have a negati

  19. Beach Nourishment and Artificial Surf Reef

    NARCIS (Netherlands)

    Klein, A.H.; De Menezes, J.T.; Sperb, R.S.; Siegle, E.; Fontura, R.; Van de Graaff, J.; Stive, M.J.F.; Van der Schrieck, G.L.M.; Verhagen, H.J.

    2004-01-01

    Balneário Camboriú is a very touristy city in southern Brazil, situated in the five kilometer wide Camboriú Bay. Its main tourist attraction is the beach, which is 5800 m long and rather narrow with a dry width of 10 to 20 m. The city is facing several problems regarding the beach that have a negati

  20. Stability and safety of Anjuna beach, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.; Varadachari, V.V.R.

    Studies on the Anjuna Beach, Goa, India, from March to December, 1975, show that it is fairly stable though it undergoes seasonal changes and a series of short-term cuts and fills. The beach appears to be quite safe as the longshore currents...

  1. Long Beach's Pivotal Turn around RTI

    Science.gov (United States)

    Elliott, Judy

    2008-01-01

    This article briefly describes the tiered approach to intervention adopted by the Long Beach Unified School District. Long Beach Unified School District is the state's third largest urban school district with more than 90,000 students, 84 percent of whom are minority and 68 percent of whom qualify for free and reduced price lunch, and where over…

  2. Extraction of lidar-based dune-crest elevations for use in examining the vulnerability of beaches to inundation during hurricanes

    Science.gov (United States)

    Stockdon, H.F.; Doran, K.S.; Sallenger, A.H.

    2009-01-01

    The morphology of coastal sand dunes plays an important role in determining how a beach will respond to a hurricane. Accurate measurements of dune height and position are essential for assessing the vulnerability of beaches to extreme coastal change during future landfalls. Lidar topographic surveys provide rapid, accurate, high-resolution datasets for identifying the location, position, and morphology of coastal sand dunes over large stretches of coast. An algorithm has been developed for identification of the crest of the most seaward sand dune that defines the landward limit of the beach system. Based on changes in beach slope along cross-shore transects of lidar data, dune elevation and location can automatically be extracted every few meters along the coastline. Dune elevations in conjunction with storm-induced water levels can be used to predict the type of coastal response (e.g., beach erosion, dune erosion, overwash, or inundation) that may be expected during hurricane landfall. The vulnerability of the beach system at Fire Island National Seashore in New York to the most extreme of these changes, inundation, is assessed by comparing lidar-derived dune elevations to modeled wave setup and storm surge height. The vulnerability of the beach system to inundation during landfall of a Category 3 hurricane is shown to be spatially variable because of longshore variations in dune height (mean elevation 5.44 m, standard deviation 1.32 m). Hurricane-induced mean water levels exceed dune elevations along 70 of the coastal park, making these locations more vulnerable to inundation during a Category 3 storm. ?? 2009 Coastal Education and Research Foundation.

  3. Beach protection by a system of permeable groins

    Science.gov (United States)

    Boczar-Karakiewicz, B.; Romanczyk, W.; Roy, N.

    2002-12-01

    A new type of permeable groin (called System of Groins Maltec-Savard - SGMS) has been installed at three eroded sites located in the coastal area on the north shore of the St. Lawrence, Quebec, Canada. In this area, the narrow sandy beaches with sandy or sand-silty cliff of variable height (10-15~m) are exposed to obliquely incident waves arriving from both west (summer) and east (autumn), and to tidal currents (maximum tidal rate is 4.3~m). The periods of summer waves equal 3-5~s, with wave heights of about 0.4-0.7~m. In the autumn, major storm waves reach periods of up to 7-10~s, with wave heights of 1.0-1.2~m. The new groins are sediment traps formed by a central double and permeable groin with several smaller lateral, groins installed on one or both sides of the central groin (Boczar-Karakiewicz et al., 2001). The permeable central and lateral groins are structured by inserting double ranges of wooden piles (diameter of about 10 cm). The space between the ranges of piles (some 0.8~m wide) is filled with tree branches (e.g., the top parts of pine trees, a waste product of the local forest industry). A permeable grid covering the top of the groins forms a cage that holds the branches in place. The lateral groins, are identical but much shorter than the central groin. The whole system dissipates the incident energy of wave- and tidally-generated currents and causes accretion of sand transported by these currents. The GSMS also allows the by-pass of some sediment to adjacent zones without groins. Observations and results of measurements from three experiments field show that: (1) a sandy beach in front of a coastal cliff secures its stability and attenuates the erosion caused by waves and tidal currents; (2) permeability and flexibility of the SGMS causes the accretion of sediment in the protected area without erosion in the neighboring zones; (3) the SGMS does not generate wave reflection and any secondary current; (4) the materials of the groins are easily

  4. Monitoring beach changes using GPS surveying techniques

    Science.gov (United States)

    Morton, Robert; Leach, Mark P.; Paine, Jeffrey G.; Cardoza, Michael A.

    1993-01-01

    A need exists for frequent and prompt updating of shoreline positions, rates of shoreline movement, and volumetric nearshore changes. To effectively monitor and predict these beach changes, accurate measurements of beach morphology incorporating both shore-parallel and shore-normal transects are required. Although it is possible to monitor beach dynamics using land-based surveying methods, it is generally not practical to collect data of sufficient density and resolution to satisfy a three-dimensional beach-change model of long segments of the coast. The challenge to coastal scientists is to devise new beach monitoring methods that address these needs and are rapid, reliable, relatively inexpensive, and maintain or improve measurement accuracy.

  5. Sandy beaches in a coastline vulnerable to erosion in Atlantic Canada: Macrobenthic community structure in relation to backshore and physical features

    Science.gov (United States)

    MacMillan, Mitchell R.; Duarte, Cristian; Quijón, Pedro A.

    2017-07-01

    Most literature suggests that sandy beach macrobenthic communities are structured by physical factors. However, an aspect that has not been studied in detail is whether those physical factors change with erosion or the association of beaches to backshore features like sand dunes, till bluffs, and sandstone cliffs. We addressed this question by sampling 14 sandy beaches on the north shore of Prince Edward Island, Atlantic Canada. Two null hypotheses were tested: first, there is no relationship between physical factors and community descriptors across sandy beaches, and second, there is no difference among beaches associated with distinct backshore features both in terms of physical factors and community descriptors. In order to test these hypotheses, samples of macrobenthic organisms and measurements of grain size, slope, beach deposit index and erosion rates were obtained. Our surveys collected a total of 14 taxa numerically dominated by the spionid polychaete Scolelepis squamata. With regards to the first hypothesis, regression analyses showed that community descriptors were all positively related to erosion rates while unrelated to the variation in grain size, slope and beach deposit index. As for the second hypothesis, erosion rates were significantly different among beaches associated to till bluffs (highest), dunes and sandstone cliffs (lowest). Meanwhile, the other physical factors did not significantly differ among backshore features. Species richness was highest in beaches associated to till bluffs and lowest in those associated to sandstone cliffs. Abundance values were also lowest in beaches associated to sandstone cliffs, and their community composition was significantly different to those associated to dunes and till bluffs. We suggest that the relationship between erosion rates and community descriptors is complex and may be mediated by the availability of nutrients: higher erosion levels might account for higher concentrations of nutrients for

  6. Results From a Microbial Source-Tracking Study at Villa Angela Beach, Cleveland, Ohio, 2007

    Science.gov (United States)

    Bushon, Rebecca N.; Stelzer, Erin A.; Stoeckel, Donald M.

    2009-01-01

    During the 2007 recreational season at Villa Angela Beach in Cleveland, Ohio, scientists with the U.S. Geological Survey (USGS) and the Northeast Ohio Regional Sewer District (NEORSD) found high Escherichia coli (E. coli) concentrations that were not easily explained by results obtained to date in ongoing investigations of recreational water quality at the beach. To help understand the sources behind these elevated E. coli concentrations, the USGS and NEORSD sampled beach-area water for Bacteroides DNA markers. Bacteroides are a group of enteric bacteria that are being used in microbial source tracking, in hope that host-associated DNA markers could be used to indicate potential sources of E. coli in the Villa Angela environment. The USGS Ohio Water Microbiology Laboratory analyzed a total of 13 source samples (sewage and waterfowl feces) and 33 beach-area water and sand samples for three Bacteroides DNA markers. This report lists the results of those analyses, along with environmental conditions at Villa Angela on the dates that samples were collected.

  7. Morphological characteristics and sand volumes of different coastal dune types in Essaouira Province, Atlantic Morocco

    Science.gov (United States)

    Flor-Blanco, Germán; Flor, Germán; Lharti, Saadia; Pando, Luis

    2013-04-01

    Altogether three coastal dune fields, one located north and two south of the city of Essaouira, Atlantic Morocco, have been investigated to establish the distribution and overall sand volumes of various dune types. The purpose of the study was to characterize and classify the aeolian landforms of the coastal dune belt, to estimate their sand volumes and to assess the effectiveness of coastal dune stabilization measures. The northern dune field is 9 km long and lined by a wide artificial foredune complex fixed by vegetation, fences and branches forming a rectangular grid. Active and ephemeral aklé dunes border the inner backshore, while some intrusive dunes have crossed the foredune belt and are migrating farther inland. The total sand volume of the northern dune belt amounts 13,910,255 m3. The central coastal sector comprises a much smaller dune field located just south of the city. It is only 1.2 km long and, with the exception of intrusive dunes, shows all other dune types. The overall sand volume of the central dune field amounts to about 172,463 m3. The southern dune field is characterized by a narrower foredune belt and overall lower dunes that, in addition, become progressively smaller towards the south. In this sector, embryonic dunes (coppice, shadow dunes), tongue-like and tabular dunes, and sand sheets intrude from the beach, the profile of which has a stepped appearance controlled by irregular outcrops of old aeolianite and beach rock. The total volume of the southern dune field amounts 1,446,389 m3. For the whole study area, i.e. for all three dune fields combined, a sand volume of about 15,529,389 m3 has been estimated. The sand of the dune fields is derived from coastal erosion and especially the Tensift River, which enters the sea at Souira Qedima some 70 km north of Essaouira. After entering the sea, the sand is transported southwards by littoral drift driven by the mainly north-westerly swell climate and the Trade Winds blowing from the NNE. This

  8. Dynamics of Shengjini beach (Albania)

    Science.gov (United States)

    Gashi, Ferim; Nikolli, Pal

    2015-04-01

    Dynamics of Shengjini beach (Albania) Pal Nikolli , Ferim GASHI Through archaeological and historical data, presentations of ancient topographic, cartographic materials (topographic maps obtained at different periods from 1870 to 1990), aerial photographs (2007), satellite images (2014) and direct measurements, paper defines and analyzes the position of the coastline of Shengjini beach (Lezha) from century XVI until today. The coastline of the Shengjini city (port) to Drin River estuary is oriented north-south direction and is approximately 10.5 km long. This part of the coast is sandy and sediment comes mainly from the River Drin and distributed by currents along the coast. In this paper are make provision for the position of the coastline in the future and analyzed the possibilities of human intervention in the coastal environment , etc. This work forms the basis for the issuance of necessary data required for various projections at the coastal environment Shëngjini. Results of this study will have a significant impact on state policies for integrated management of the coastal zone in the study and development of tourism. Key words: GIS, Remonte Sennsing, cartography, management of coastal zone, tourism, environment.

  9. Interaction forces in bitumen extraction from oil sands.

    Science.gov (United States)

    Liu, Jianjun; Xu, Zhenghe; Masliyah, Jacob

    2005-07-15

    Water-based extraction process (WBEP) has been successfully applied to bitumen recovery from Athabasca oil sand ore deposits in Alberta. In this process, two essential steps are involved. The bitumen first needs to be "liberated" from sand grains, followed by "aeration" with air bubbles. Bitumen "liberation" from the sand grains is controlled by the interaction between the bitumen and sand grains. Bitumen "aeration" is dependent, among other mechanical and hydrodynamic variables, on the hydrophobicity of the bitumen surface, which is controlled by water chemistry and interactions between bitumen and fine solids. In this paper, the interaction force measured with an atomic force microscope (AFM) between bitumen-bitumen, bitumen-silica, bitumen-clays and bitumen-fines is summarized. The measured interaction force barrier coupled with the contacted adhesion force allows us to predict the coagulative state of colloidal systems. Zeta potential distribution measurements, in terms of heterocoagulation, confirmed the prediction of the measured force profiles using AFM. The results show that solution pH and calcium addition can significantly affect the colloidal interactions of various components in oil sand extraction systems. The strong attachment of fines from a poor processing ore on bitumen is responsible for the corresponding low bitumen flotation recovery. The identification of the dominant non-contact forces by fitting with the classical DLVO or extended DLVO theory provides guidance for controlling the interaction behavior of the oil sand components through monitoring the factors that could affect the non-contact forces. The findings provide insights into megascale industrial operations of oil sand extraction.

  10. Bituminous sands : tax issues

    Energy Technology Data Exchange (ETDEWEB)

    Patel, B. [PricewaterhouseCoopers LLP, Calgary, AB (Canada)

    2004-07-01

    This paper examined some of the tax issues associated with the production of bitumen or synthetic crude oil from oil sands. The oil sands deposits in Alberta are gaining more attention as the supplies of conventional oil in Canada decline. The oil sands reserves located in the Athabasca, Cold Lake and Peace River areas contain about 2.5 trillion barrels of highly viscous hydrocarbons called bitumen, of which nearly 315 billion barrels are recoverable with current technology. The extraction method varies for each geographic area, and even within zones and reservoirs. The two most common extraction methods are surface mining and in-situ extraction such as cyclic steam stimulation (CSS); low pressure steam flood; pressure cycle steam drive; steam assisted gravity drainage (SAGD); hot water flooding; and, fire flood. This paper also discussed the following general tax issues: bituminous sands definition; bituminous sands leases and Canadian development expense versus Canadian oil and gas property expense (COGPE); Canadian exploration expense (CEE) for surface mining versus in-situ methods; additional capital cost allowance; and, scientific research and experimental development (SR and ED). 15 refs.

  11. What drives nearshore sediment transport controls on the depletion of beach placers at Manavalakurichi, Southwest Coast of India?.

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; ManiMurali, R.; Babu, M.T.; Sudheesh, K.; Vethamony, P.; NaveenKumar, K.R.

    7000 km, large deposits of beach sand minerals have been reported at selected locations in the coastal stretches of peninsular India (Ali, Krishnan, &Banerjee, 2001; AMD, 2000; Ashwathanarayana, 1964; GSI, 1976; Gujar, 1996; Hashimi, Kidwai, & Nair...). The hydrodynamic simulation has been done for the different scenarios of bathymetry of the study region. Simulation results were validated with the field data generated therein. Hydrodynamic simulation was carried out for the following scenarios: Case (i...

  12. Trials of bioremediation on a beach affected by the heavy oil spill of the Prestige.

    Science.gov (United States)

    Fernández-Alvarez, P; Vila, J; Garrido-Fernández, J M; Grifoll, M; Lema, J M

    2006-10-11

    The objective of this study was to assess the efficiency of several bioremediation products in accelerating the in situ biodegradation of the heavy fuel oil spill of the Prestige. Trials of bioremediation were conducted in sand, rocks and granite tiles on the beach of Sorrizo (A Coruña, NW Spain) that was polluted by the spill. Neither the added microorganisms nor the nutrients significantly enhanced the degradation rate of the fuel oil in rocks, granite tiles or sand. PAH degradation up to 80% was determined in sand and tiles. In tiles the oxygen content of the residual oil increased from 1.6% up to 8% in 90 days, which could be explained by the accumulation of products coming from the partial oxidation of the hydrocarbons. Eighteen months after the spill, the rocks of the beach were still coated by a black layer of weathered fuel oil. For this reason an oleophilic product, sunflower biodiesel was tested on a rock. The application of biodiesel accelerated the gradually clean-up of the polluted surface and could also accelerate the degradation of the residual oil.

  13. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...... test, Grain density, ds, Maximum, emax, and minimum, emin, void ratio. The strength parameters of Lund No 0 are detennined by some drained and undrained triaxial tests in the Danish Triaxial Cell. The Danish Triaxial Cell prescribes smooth pressure heads and specimens with equal height and diameter....... Four series with Id equal to 0.92, 0.87 0.76 and 0.55 have been performed....

  14. Capture of Caliptrate flies with different breeding substrates on beaches in Rio de Janeiro, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    José Mário D'Almeida

    1993-06-01

    Full Text Available Muscidae flies belonging to four Familia and 13 species in a total number of 3.652 specimens were collected from beaches at Ilha do Governador, Rio de Janeiro, Brazil using different breeding substrates, and subsequently bred in the laboratory. Captures were done from April to November 1989, using in a first phase different substrates: fruits (banana and papaya, vegtable (tomato, animal viscera (bovine liver, marine animals (fish, crab, shrimp, squid, mouse carcass and feaces (human and canine. The species collected more often were: Fannia sp. (subgroup pusio, Chrysomya megacephala, Phaenicia eximia, Synthesiomyia nudiseta, Peckya chrysostoma, Musca domestica and Atherigona orientalis. In a later phase, only fish was used, as bait and placed directly on the beach sand. From a total of 189 pupae, the following adult specimen were obtained: Peckia chrysostoma (58.06%, Chrysomya megacephala (30.64% and in lesser numbers Synthesiomyia nudiseta and Phaenicia eximia.

  15. Assessing shelf aggregate environmental compatibility and suitability for beach nourishment: a case study for Tuscany (Italy).

    Science.gov (United States)

    Bigongiari, Nicola; Cipriani, Luigi E; Pranzini, Enzo; Renzi, Monia; Vitale, Giovanni

    2015-04-15

    Beach nourishment practices are a key aspect in coastal management plans for stakeholders and communities. Stemming from a concrete case-study (Tuscany), this research analyzes: (i) principal problems of current law regulating dredging, (ii) gaps in technical guidelines, (iii) advantages of integrated approaches to the decision-making process, (iv) possible applicable nourishment options and their costs and benefits. Our results show that sand compatibility is driven mainly by grain-size stability due to the occurrence of lower pollution levels in off-shore deposits than in threatened beaches, thus current laws and guidelines should be improved to fill the evident gap in the evaluation process and to include a more complete approach to data evaluation and an integrated approach to ecotoxicity evaluation, which is relevant in cases of geochemical anomalies. The cost-benefit analysis performed indicates that only dredging intended to manage more than 1 million m(3) of aggregates would represent a real advantage for local communities.

  16. Indications of a positive feedback between coastal development and beach nourishment

    Science.gov (United States)

    Armstrong, Scott; Lazarus, Eli; Limber, Patrick W.; Goldstein, Evan; Thorpe, Curtis; Ballinger, Rhoda

    2016-01-01

    Beach nourishment, a method for mitigating coastal storm damage or chronic erosion by deliberately replacing sand on an eroded beach, has been the leading form of coastal protection in the U.S. for four decades. However, investment in hazard protection can have the unintended consequence of encouraging development in places especially vulnerable to damage. In a comprehensive, parcel-scale analysis of all shorefront single-family homes in the state of Florida, we find that houses in nourishing zones are significantly larger and more numerous than in non-nourishing zones. The predominance of larger homes in nourishing zones suggests a positive feedback between nourishment and development that is compounding coastal risk in zones already characterized by high vulnerability.

  17. Modern changes of tidal troughs among the radial sand ridges in northern Jiangsu coastal zone

    Institute of Scientific and Technical Information of China (English)

    HUANG Haijun; DU Tingqin; GAO Ang

    2009-01-01

    Using satellite images taken on different dates, GIS analysis of aerial photos, bathymetric maps and other field survey data, tidal troughs and major sand ridges in the northern Jiangsu coastal area were contrasted. The results show that there have been three types of movement or migration of tidal trough in this area: (1) Periodic and restricted, this type of trough usually developed along the beaches with immobile gully head as a result of the artificial dams and the swing range increased from gully head to the low reaches, so they have been obviously impacted by human activity and have longer swing periods; (2) Periodic and actively, this kind of trough, which swung with a fast rate and moved periodically on sand ridges, were mainly controlled by the swings of the host tidal troughs and hydrodynamic forces upon tidal sand ridge and influenced slightly by human constructions; (3) Steadily and slowly, they are the main tidal troughs with large scale and a steady orientation in this area and have slow lateral movement. The differences in migration mode of tidal trough shift result in different rates of migration and impact upon tidal sand ridges. Lateral accumulation on current tidal trough and deposition on abandoned tidal troughs are the two types of sedimentation of the tidal sand ridges formation. The whole radial sand ridge was generally prone to division and retreat although sand ridges fluctuated by the analysis of changes in talwegs of tidal troughs and shorelines of sand ridges.

  18. The technique of sand control with expandable screens

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, P. [Petrochina, Liaohe (China). Liaohe Oilfield Co.

    2009-07-01

    Sand production in heavy oil reservoirs can limit the normal production of oil wells. In this study, expandable screens were used as a sand control mechanism by filtering the sand as it entered the wellbore. The screen systems consists of an expandable outer housing, an expandable base pipe and a filtering layer. The screen expands radially through an expandable cone and presses into the casing well. Axial tension is used to shrink the screens radially through a fishing anchor in order to remove them from the well. The lack of a sand ring between the screen and the casing increases the flow area of the oil and reduces flow resistance caused by fine silt blockages. A series of laboratory experiments were conducted to study the expansion and shrinkage properties of the screens. A field test conducted at a well located in the Liaohe oilfield in China demonstrated that good sand control results can be obtained without the need for pump checking. It was concluded that the sand control method is easy to use and provides good sand control results in large open flow areas. 2 refs., 2 tabs., 3 figs.

  19. UK Frac Sand Resources

    OpenAIRE

    Mitchell, C J

    2015-01-01

    Although still just a glimmer in the gas man’s eye, the prospect of shale hydrocarbon (oil and gas) development in the UK has many companies thinking about the industrial minerals it will require. Chief amongst these is silica sand which is used as a ‘proppant’ in the hydraulic fracturing, or ‘fracking’, of shales to help release the gas. The UK has large resources of sand and sandstone, of which only a small proportion have the necessary technical properties that classify them as ‘silica san...

  20. Beach Advisory and Closing Online Notification (BEACON) system

    Science.gov (United States)

    Beach Advisory and Closing Online Notification system (BEACON) is a colletion of state and local data reported to EPA about beach closings and advisories. BEACON is the public-facing query of the Program tracking, Beach Advisories, Water quality standards, and Nutrients database (PRAWN) which tracks beach closing and advisory information.

  1. Sand Behavior Induced by High-Speed Penetration of Projectile. Phenomenological studies of the response of granular and geological media to high-speed (Mach 1-5) projectiles

    Science.gov (United States)

    2011-02-07

    are summarized as follows: Sands around the penetrated projectile were smashed to fine powder of 5 µm or less like a potato starch . Circumferential...Distribution Sands around the penetrated projectile were smashed to fine powder of 5 µm or less like a potato starch as shown in Fig.11. It was found that...The major results are summarized as follows: 1. Sands around the penetrated projectile were smashed to fine powder of 5 µm or less like a potato

  2. Geologic records of Pleistocene, Holocene and Anthropocene beach profiles?

    Science.gov (United States)

    Dougherty, Amy; Choi, Jeong-Heon; Dosseto, Anthony

    2017-04-01

    morphodynamics to interpret paleoenvironmental histories. Data from prograded barriers in North America, New Zealand and Australia are used to illustrate the potential of utilizing GPR, OSL, and LiDAR. Exploiting the fundamental link between paleo-beachfaces and past ocean levels, new sea level curves were constructed by mapping their height over time. Examples from far-field sites capture Eemian and mid-Holocene highstands with a subsequent fall indicating a non-linear nature. The geometry of paleo-beachfaces, intrinsically linked to wave-energy, were analyzed in comparison to present-day beach profile data to extract storm records. The results yielded recurrence intervals with differing coastal impacts, which indicated storm intensity increased as frequency decreased. Volumes of the barrier lithesome were quantified to provide insight on sediment supply and accommodation space over time. Findings show sand supply increased drastically starting in the mid-19th century causing a shift in foredune evolution from previous millennia. Do anomalous foredunes define Anthropocene coastal barriers in the geologic record? Global stratigraphic signatures, distinct from Holocene deposits, are needed to formally establish this 'Human' Epoch. Applying this novel methodology to the more than 300 prograded barriers around the world, including 50+ in Europe, can: 1) augment traditional proxy from ice and sediment cores to help delineate the Anthropocene, 2) determine changes in coastlines since the onset of global warming, and 3) provide insight, and input to forecasting models, needed to mitigate and manage future impacts of climate change.

  3. On the role of Posidonia oceanica beach wrack for macroinvertebrates of a Tyrrhenian sandy shore

    Science.gov (United States)

    Colombini, Isabella; Mateo, Miguel Ángel; Serrano, Oscar; Fallaci, Mario; Gagnarli, Elena; Serrano, Laura; Chelazzi, Lorenzo

    2009-01-01

    The use of Posidonia oceanica beach wrack by macroinvertebrates of the sandy beach at Burano (Tuscany, Italy) was assessed by following the colonisation dynamics of the wrack and analysing the stable isotopes 'scenario' of the main local carbon and nitrogen sources and consumers. One-hundred experimental cylinders, filled with P. oceanica wrack, were placed on the beach and sampled over a 1-month period. Abundance and species richness of macroinvertebrates in wracks varied through time. Wrack was colonised by crustaceans almost immediately after deployment of the experimental cylinders. The amphipod Talitrus saltator largely dominated the faunal assembly and, together with the isopod Tylos europaeus, occupied the wracks closer to the sealine. These were followed by dipterans, staphylinids, pselaphids and tenebrionids that occurred in drier wracks higher up on the eulittoral. Moisture content of the wrack and sand decreased through space and time. This was the primary factor explaining the spatial and temporal changes observed in macroinvertebrate abundance, with species colonising or abandoning wracks according to thresholds of environmental parameters. Isotopic analysis clearly established the absence of any direct dietary link between P. oceanica wrack and macroinvertebrates. Terrestrial food sources were also discarded. Both our experimental data and a literature search showed that the organic matter from seston as filtered by the sand is the most plausible carbon and nitrogen source for beach food webs. Even if P. oceanica wrack is not a trophic source for macroinvertebrates, it is vitally important as a physical structure that provides detritivorous and predatory species with refuge from environmentally stressful conditions.

  4. Transport velocities of coal and sand particles

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J. (Inst. de Carboquimica, Zaragoza (Spain)); Diego, L.F. de (Inst. de Carboquimica, Zaragoza (Spain)); Gayan, P. (Inst. de Carboquimica, Zaragoza (Spain))

    1993-10-01

    Transport velocities of narrow cut sizes of coarse particles of sand and coal were determined at room temperature and atmospheric pressure. These velocities were obtained by four different methods previously utilized by other authors with fine particles. The four methods tested gave good predictions of the transport velocities. The method based on the measurement of the time required for all the solids to leave the bed without feeding in any fresh solid is specially interesting because of its rapidity and simplicity. The determined transport velocities were strongly dependent on the solid particle size and density. The experimental values were fitted to an equation which fitted both the experimental results obtained in this work and other published results obtained with fine particles. (orig.)

  5. Combining remote sensing with an inverse Bruun Rule for the analysis and management of almost equilibrium beaches

    Science.gov (United States)

    Eelsalu, Maris; Soomere, Tarmo; Männikus, Rain

    2016-04-01

    The management of beaches that suffer from sediment deficit and construction of nearshore infrastructure in locations with intense sediment transit require adequate predictions of the future of the relevant sedimentary systems. To a large extent, this task can be accomplished by using jointly the information about sediment texture and long-term changes in the dry beach volume and the location of the waterline. It is straightforward to evaluate relative changes in the dry beach volume from a succession of airborne laser scanning (ALS) surveys. We use in addition terrestrial laser scanning (TLS) technique to reduce ALS surveys performed with different devices and from different height to the same absolute height. This is accomplished using a TLS survey of a large horizontal surface of constant elevation within ALS snapshots. The most complicated, time-consuming and expensive task in beach management and planning of nearshore infrastructure is to get an adequate picture of the intensity and direction of underwater sediment transport processes. We demonstrate how a simple application of so-called inverse Bruun Rule makes it possible to evaluate the underwater volumetric changes for almost equilibrium beaches. The approach requires three data sets: wave statistics, sediment texture and changes in the average position of the waterline. The main properties of the wave climate, closure depths, magnitude and direction of wave-driven alongshore transport near the test areas are established using a triple nested high-resolution version of the wave model WAM that is forced for 34 years by high-quality marine winds. The relocation of the waterline is extracted from the ALS scanning of elevation isolines of 0.4-0.7 m on the subaerial beach. The technique has been applied to two basically different sections of Tallinn Bay, the Baltic Sea. Pirita Beach is gradually losing sand and requires beach refill while a moderate reclamation action is planned in the vicinity of gradually

  6. Connecting onshore and offshore near-surface geology: Delaware's sand inventory project

    Science.gov (United States)

    Ramsey, K.W.; Jordan, R.R.; Talley, J.H.

    1999-01-01

    Beginning in 1988, the Delaware Geological Survey began a program to inventory on-land sand resources suitable for beach nourishment. The inventory included an assessment of the native beach textures using existing data and developing parameters of what would be considered suitable sand textures for Delaware's Atlantic beaches. An assessment of the economics of on-land sand resources was also conducted, and it was determined that the cost of the sand was competitive with offshore dredging costs. In addition, the sand resources were put into a geologic context for purposes of predicting which depositional environments and lithostratigraphic units were most likely to produce suitable sand resources. The results of the work identified several suitable on-land sand resource areas in the Omar and Beaverdam formations that were deposited in barrier-tidal delta and fluvial-estuarine environments, respectively. The identified on-land resources areas have not been utilized due to difficulties of truck transport and development pressures in the resource areas. The Delaware Geological Survey's participation in years 8, 9, and 10 of the Continental Margins Program was developed to extend the known resource areas onshore to offshore Delaware in order to determine potential offshore sand resources for beach nourishment. Years 8 and 9 involved primarily the collection of all available data on the offshore geology. These data included all seismic lines, surface grab samples, and cores. The data were filtered for those that had reliable locations and geologic information that could be used for geologic investigations. Year 10 completed the investigations onshore by construction of a geologic cross-section from data along the coast of Delaware from Cape Henlopen to Fenwick. This cross section identified the geologic units and potential sand resource bodies as found immediately along the coast. These units and resources are currently being extended offshore and tied to known and

  7. Observation of microstructure of silty sand obtained from gelpush sampler and reconstituted sample

    Science.gov (United States)

    Yusa, Muhamad; Bowman, E. T.; Cubrinovski, Misko

    2017-06-01

    Observation of microstructure study of natural sand i.e. clean sand with fines (particles adjudged to be smaller than 75μm) content < 5% (Gel Push A) and silty sand with 35% fine content (Gel Push B) obtained by gel-push sampling was described. In addition, some observations from reconstituted samples prepared by dry pluviation and moist tamping were presented. Microstructures were investigated statistically by measuring particle orientation. It was evidence that natural sand (either gel push A and B) have a preferred orientation i.e. horizontally oriented. Similar particle orientation trend were observed by dry pluviated sample. Undisturbed and dry pluviated samples shows that they are anisotropic in terms of particles orientation. Moist tamped sample on the other hand, results in fairly random orientation with a slight bias towards vertical, thus does not replicate natural sand fabric.

  8. 78 FR 33969 - Special Local Regulations; Daytona Beach Grand Prix of the Sea, Atlantic Ocean; Daytona Beach, FL

    Science.gov (United States)

    2013-06-06

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulations; Daytona Beach Grand Prix of the Sea, Atlantic Ocean; Daytona Beach, FL AGENCY: Coast Guard, DHS. ACTION: Temporary final rule... east of Daytona Beach, Florida, during the Daytona Beach Grand Prix of the Sea, a series of...

  9. 75 FR 24997 - FPL Energy Point Beach, LLC; Point Beach Nuclear Plant, Units 1 and 2; Environmental Assessment...

    Science.gov (United States)

    2010-05-06

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION FPL Energy Point Beach, LLC; Point Beach Nuclear Plant, Units 1 and 2; Environmental Assessment... Energy Point Beach, LLC (the licensee), for operation of the Point Beach Nuclear Plant, Units 1 and 2...

  10. Human impact, geomorphological and bio-environmental indicators for mapping and monitoring of a Mediterranean urban-beach with Posidonia oceanica (Gulf of Cagliari-Sardinia)

    Science.gov (United States)

    De Muro, Sandro; Pusceddu, Nicola; Frongia, Paolo; Buosi, Carla; Passarella, Marinella; Ibba, Angelo

    2016-04-01

    This work describes the human conditioned evolution (medium term) and the short term dynamics (mainly sediment transport) in southern Sardinia beach (between Giorgino and Cala d'Orri, about 11km), composed of fine to coarse quartz sand, backed by dune ridges and lagoons. The study was founded by NEPTUNE Project, Tender6 (L n. 7/2007). Geomorphological and bio-environmental indicators as: urbanization and coastal defence expansion, dune and beach changes, biotic indices (benthic foraminifera and Posidonia meadow) have been used. Medium-term evolution, over a period of 60 years, was carried out by ortho-images (1954-2015) for reconstructing coastline changes at this temporal scale. The main modifications were the building of the canal harbor, the consequent loss of 2.5km of beach, and the construction of several coastal defense structures, which caused asymmetric accumulations (lee zones) and erosion areas. Short-term variations have been periodically monitored (2014-2015) during 5 different field surveys (DGPS and Echo-sounder data) obtaining topo-bathymetric digital models. Sedimentary and hydrodynamic characteristics have been studied. Wave propagation, coastal currents and sediment transport, have been simulated through numerical models within Delft3D software. The results obtained allowed to visualize the response of the beach to wave stress, forced from SW, S, SE (Cagliari buoy and weather data). The comparison between data collected, thematic maps and models allowed to identify the main controlling factors and distribution mechanisms of the sedimentary paths on the shoreface. Those human modifications (e.g. building of the canal harbour and jetties, lagoon mouths stabilization, the consequent modified hydrodynamics and bottom trawling) have direct influence on the Posidonia oceanica and on its upper limit. In 2002, the Italian Environment Office reported a wide area (between -4m and -20m) of degraded Posidonia and dead matte in front of the study beach

  11. Horizontal and vertical distribution of meiofauna on sandy beaches of the North Sea (The Netherlands, Belgium, France)

    Science.gov (United States)

    Kotwicki, Lech; Troch, Marleen De; Urban-Malinga, Barbara; Gheskiere, Tom; Węslawski, Jan Marcin

    2005-11-01

    Sandy intertidal zones were analysed for the presence of meiofauna. The material was collected on six macro-tidal sandy beaches along the North Sea (The Netherlands, France, Belgium), in order to analyse the vertical and horizontal meiofaunal distribution patterns. Eleven higher meiofauna taxa (one represented by larval stage—Copepoda nauplii) were recorded. The maximum total meiofauna abundance was observed on the Dutch beach (4,295±911 ind. 10 cm-2) in the Westerschelde estuary, while the lowest values (361±128 ind. 10 cm-2) were recorded in France at the Audresselles beach. Meiofauna of the different localities consisted mainly of nematodes, harpacticoids and turbellarians. Nematodes numerically dominated all sampled stations, comprising more than 45% of the total meiofauna density. Meiofauna was mainly concentrated at the sand surface with about 70% present in the uppermost 5 cm. Meiofauna occurred across the entire intertidal zone. A clear zonation pattern in the distribution of meiofauna taxa across the beaches was observed. The present work suggests that designation of exposed sandy beaches as physically controlled (McLachlan 1988) does not explain their biological variability.

  12. Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

    Science.gov (United States)

    Markewich, H.W.; Pavich, M.J.; Schultz, A.P.; Mahan, S.A.; Aleman-Gonzalez, W. B.; Bierman, P.R.

    2013-01-01

    Predominantly clastic, off-lapping, transgressive, near-shore marine sediment packages that are morphologically expressed as subparallel NE-trending barriers, beach ridges, and associated back-barrier areas, characterize the near-surface stratigraphic section between the Savannah and the Ogeechee Rivers in Effingham County, southeastern Georgia. Each barrier/back-barrier (shoreline) complex is lower than and cut into a higher/older complex. Each barrier or shoreline complex overlies Miocene strata. No direct age data are available for these deposits. Previous researchers have disagreed on their age and provenance. Using luminescence and meteoric beryllium-10 (10Be) inventory analyses, we estimated a minimum age for the largest, westernmost, morphologically identifiable, and topographically-highest, barrier/beach-ridge (the Wicomico shoreline barrier) and constrained the age of a suite of younger barrier/beach-ridges that lie adjacent and seaward of the Wicomico shoreline barrier. At the study site, the near-shore marine/estuarine deposits underlying the Wicomico shoreline barrier are overlain by eolian sand and an intervening zone-of-mixing. Optically stimulated luminescence (OSL) data indicate ages of ≤43 ka for the eolian sand and 116 ka for the zone-of-mixing. Meteoric 10Be and pedostratigraphic data indicate minimum residence times of 33.4 ka for the eolian sand, 80.6 ka for the zone-of-mixing, and 247 ka for the paleosol. The combined OSL and 10Be age data indicate that, at this locality, the barrier/beach ridge has a minimum age of about 360 ka. This age for the Wicomico shoreline-barrier deposit is the first for any Pleistocene near-shore marine/estuarine deposit in southeast Georgia that is conclusively older than 80 ka. The 360-ka minimum age is in agreement with other geochronologic data for near-coastline deposits in Georgia and South Carolina. The geomorphic position of this barrier/beach-ridge is similar to deposits in South Carolina considered to be

  13. Geochronologic evidence for a possible MIS-11 emergent barrier/beach-ridge in southeastern Georgia, USA

    Science.gov (United States)

    Markewich, H. W.; Pavich, M. J.; Schultz, A. P.; Mahan, S. A.; Aleman-Gonzalez, W. B.; Bierman, P. R.

    2013-01-01

    Predominantly clastic, off-lapping, transgressive, near-shore marine sediment packages that are morphologically expressed as subparallel NE-trending barriers, beach ridges, and associated back-barrier areas, characterize the near-surface stratigraphic section between the Savannah and the Ogeechee Rivers in Effingham County, southeastern Georgia. Each barrier/back-barrier (shoreline) complex is lower than and cut into a higher/older complex. Each barrier or shoreline complex overlies Miocene strata. No direct age data are available for these deposits. Previous researchers have disagreed on their age and provenance. Using luminescence and meteoric beryllium-10 (10Be) inventory analyses, we estimated a minimum age for the largest, westernmost, morphologically identifiable, and topographically-highest, barrier/beach-ridge (the Wicomico shoreline barrier) and constrained the age of a suite of younger barrier/beach-ridges that lie adjacent and seaward of the Wicomico shoreline barrier. At the study site, the near-shore marine/estuarine deposits underlying the Wicomico shoreline barrier are overlain by eolian sand and an intervening zone-of-mixing. Optically stimulated luminescence (OSL) data indicate ages of ≤43 ka for the eolian sand and 116 ka for the zone-of-mixing. Meteoric 10Be and pedostratigraphic data indicate minimum residence times of 33.4 ka for the eolian sand, 80.6 ka for the zone-of-mixing, and 247 ka for the paleosol. The combined OSL and 10Be age data indicate that, at this locality, the barrier/beach ridge has a minimum age of about 360 ka. This age for the Wicomico shoreline-barrier deposit is the first for any Pleistocene near-shore marine/estuarine deposit in southeast Georgia that is conclusively older than 80 ka. The 360-ka minimum age is in agreement with other geochronologic data for near-coastline deposits in Georgia and South Carolina. The geomorphic position of this barrier/beach-ridge is similar to deposits in South Carolina considered to be

  14. Morphology and composition of beach-cast Posidonia oceanica litter on beaches with different exposures

    Science.gov (United States)

    Simeone, Simone; De Falco, Giovanni

    2012-05-01

    Posidonia oceanica seagrass litter is commonly found along sandy shores in the Mediterranean region, forming structures called banquettes, which are often removed in order to allow the beach to be used for tourism. This paper evaluates the relationship between the morphology and composition of banquettes and beach exposure to dominant waves. A Real Time Kinematic Differential Global Positioning System was used to evaluate the variability of banquettes and beach morphology over a period of 1 year. Banquette samples, collected at two different levels of the beach profile (i.e. foreshore and backshore), were used to evaluate the contribution of leaves, rhizomes and sediments to the total weight. Banquettes showed a higher volume, thickness and cross-shore length on exposed beaches, whereas narrower litter deposits were found on the sheltered beach. On exposed beaches, banquettes were deposited in beach zones characterized by changes in elevation. These changes in elevation were mainly due to the deposition and erosion of sediments and secondly to the deposition and or erosion of leaf litter. On sheltered beaches, the variability in beach morphology was low and was restricted to areas where the banquettes were located. The leaf/sediment ratio changed along the cross-shore profile. On the backshore, banquettes were a mixture of sediments and leaves, whereas leaves were the main component on the foreshore, independently of the beach exposure. The processes which control the morphodynamics in the swash zone could explain the variability of banquette composition along the cross-shore profile. Finally, this study highlighted that Posidonia oceanica seagrass litter plays an important role in the geomorphology of the beachface and its removal can have a harmful impact on the beaches.

  15. Morphodynamics of a mesotidal rocky beach: Palmeras beach, Gorgona Island National Natural Park, Colombia

    Science.gov (United States)

    Gómez-García, A. M.; Bernal, G. R.; Osorio, A. F.; Botero, V.

    2014-10-01

    The response of a rocky beach to different possible combinations of hydrodynamic conditions (tides, waves, oceanic currents) has been little studied. In this work, the morphodynamic response to different hydrodynamic forcing is evaluated from sedimentological and geomorphological analysis in seasonal and medium term (19 years) scale in Palmeras beach, located in the southwest of Gorgona Island National Natural Park (NNP), a mesotidal rocky island on the Colombian Pacific continental shelf. Palmeras is an important nesting area of two types of marine turtles, with no anthropogenic stress. In the last years, coastal erosion has reduced the beach width, restricting the safe areas for nesting and conservation of these species. Until now, the sinks, sources, reservoirs, rates, and paths of sediments were unknown, as well as their hydrodynamic forcing. The beach seasonal variability, from October 2010 to August 2012, was analyzed based on biweekly or monthly measurements of five beach profiles distributed every 200 m along the 1.2 km of beach length. The main paths for sediment transport were defined from the modeling of wave currents with the SMC model (Coastal Modeling System), as well as the oceanic currents, simulated for the dry and wet seasons of 2011 using the ELCOM model (Estuary and Lake COmputer Model). Extreme morphologic variations over a time span of 19 years were analyzed with the Hsu and Evans beach static equilibrium parabolic model, from one wave diffraction point which dominates the general beach plan shape. The beach lost 672 m3/m during the measuring period, and erosional processes were intensified during the wet season. The beach trends responded directly to a wave mean energy flux change, resulting in an increase of up to 14 m in the width northward and loss of sediments in the beach southward. This study showed that to obtain the integral morphodynamic behavior of a rocky beach it is necessary to combine information of hydrodynamic, sedimentology

  16. Long-term effects of beach nourishment on intertidal invertebrates

    OpenAIRE

    Wooldridge, Tyler Brock

    2015-01-01

    Although beach nourishment is an increasingly popular means to remediate coastal erosion, no consensus exists regarding how long nourishment affects sandy beach intertidal invertebrates, key components of sandy beach ecosystems. We monitored the intertidal invertebrate community for fifteen months following a nourishment project at eight beaches across San Diego County. Each beach was split into nourished and control sections. Nearly all taxa showed major declines in abundance immediately fol...

  17. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  18. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  19. Virksomhedens sande ansigt

    DEFF Research Database (Denmark)

    Lundholt, Marianne Wolff

    2017-01-01

    Er modhistorier en byrde eller en styrke i forandringsprocesser? Hvad stiller vi op, når adgangen til organisationens sande identitet går gennem medarbejdernes modhistorier? Når vi sammenholder denne erkendelse med vores viden om, at medarbejdere helt naturligt afholder sig fra at videregive disse...

  20. Sand (CSW4)

    CSIR Research Space (South Africa)

    Estuarine and Coastal Research Unit

    1982-12-01

    Full Text Available This report is one of a series on Cape Estuaries being published under the general title "The Estuaries of the Cape, Part 2". The report provides information on sand estuary: historical background, abiotic and biotic characteristics. It is pointed...

  1. A shoreline sand wave formation event at Dungeness, UK.

    Science.gov (United States)

    Falqués, A.; Arriaga, J.; Francesca, R.; Eddie, C.

    2016-12-01

    Alongshore rhythmic morphological patterns at different length scales are quite common along sandy beaches. Well known examples are megacusps and crescen