WorldWideScience

Sample records for causeways

  1. Modeling the effect of Causeways on Circulation in the Banana River

    Science.gov (United States)

    Saberi, A.; Weaver, R. J.

    2015-12-01

    The Indian River Lagoon (IRL) is a restricted estuary along the east coast of Florida. Although Banana River, a 50 km long sub-basin of IRL, has an outlet to the ocean through the Port Canaveral locks, the locks remain closed when there is no passing vessel. The lack of direct ocean connection results in limited circulation, long flushing time and poor water quality. Existence of the causeways limits the circulation even more. In this study, the impact of the causeways on flushing time is studied. This study also examines the extent to which constructing a low crested weir adjacent to Port Canaveral can improve flushing in this region. ADCIRC 2DDI is forced with meteorological inputs as well as tides to simulate the hydrodynamic properties of the study area and determine the 2D depth-averaged velocity field for four separate cases: Existing System with and without consideration of the causeways, and modified system (adding a weir near port Canaveral) with and without consideration of the causeways. Passive particles are placed in Banana River, and their movement is tracked using a Lagrangian Particle Tracking Model (LPTM). Transport timescales are then computed, and residence time contours as well as pathlines of selected particles are plotted. Results indicate that the narrow raised pathway section of the causeways acts as a plate which diverts the flow direction and generates eddies in the downstream which causes the particles in the vicinity of the causeways remain in the domain for a longer duration. There is a longer residence time for the case in which the causeways are considered. The results with the added weir suggest a noticeable improvement in flushing time and residence time even for the case in which the causeways are considered in the model.

  2. 78 FR 20451 - Drawbridge Operation Regulations; Pelican Island Causeway, Galveston, Channel, TX

    Science.gov (United States)

    2013-04-05

    ... CFR Code of Federal Regulations DHS Department of Homeland Security FR Federal Register NPRM Notice of... discretionary regulatory actions. In particular, the Act addresses actions that may result in the expenditure by a State, local, or tribal government, in the aggregate, or by the private sector of...

  3. Exposure to methyl tert-butyl ether, benzene, and total hydrocarbons at the Singapore-Malaysia causeway immigration checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.; Ong, H.Y.; Kok, P.W. [and others

    1996-12-31

    The primary aim of this study was to determine the extent and levels of exposure to volatile organic compounds (VOCs) from automobile emissions in a group of immigration officers at a busy cross-border checkpoint. A majority (80%) of the workers monitored were exposed to benzene at levels between 0.01 and 0.5 ppm, with only 1.2% exceeding the current Occupational Safety and Health Administration occupational exposure limit of 1 ppm. The geometric mean (GM) concentrations of 8-hr time-weighted average exposure were 0.03 ppm, 0.9 ppm, and 2.46 ppm for methyl-tert-butyl ether (MTBE), benzene, and total hydrocarbons (THC), respectively. The highest time-weighted average concentrations measured were 1.05 ppm for MTBE, 2.01 ppm for benzene, and 34 ppm for THC. It was found that motorbikes emitted a more significant amount of pollutants compared with motor cars. On average, officers at the motorcycle booths were exposed to four to five times higher levels of VOCs (GMs of 0.07 ppm, 0.23 ppm, and 4.7 ppm for MTBE, benzene, and THC) than their counterparts at the motor car booths (GMs of 0.01 ppm, 0.05 ppm, and 1.5 ppm). The airborne concentrations of all three pollutants correlated with the flow of vehicle traffic. Close correlations were also noted for the concentrations in ambient air for the three pollutants measured. Benzene and MTBE had a correlation coefficient of 0.97. The overall findings showed that the concentrations of various VOCs were closely related to the traffic density, suggesting that they were from a common source, such as exhaust emissions from the vehicles. The results also indicated that although benzene, MTBE, and THC are known to be volatile, a significant amount could still be detected in the ambient environment, thus contributing to our exposure to these compounds. 4 refs., 6 figs.

  4. 77 FR 50929 - Security Zones; 2012 RNC Bridge Security Zones, Captain of the Port St. Petersburg Zone, Tampa, FL

    Science.gov (United States)

    2012-08-23

    ... Causeway (60); Sand Key Bridge (699); Belleair Causeway Bridge; Walsingham Rd Bridge (688); Park Blvd. (co... of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory Information... surrounding waters to stop or impede maritime traffic during the event. The security zones and...

  5. 19 CFR 103.1 - Public reading rooms.

    Science.gov (United States)

    2010-04-01

    ... copied: United States Customs Service (Headquarters), 1300 Pennsylvania Avenue, NW., Washington, DC 20229 Boston, 10 Causeway Street, Boston, Massachusetts 02222 New York, One Penn Plaza, 10th Floor, New...

  6. Natural and Artificial Connections between Atoll Islets in the Pacific, Their Process and Environmental Impact

    Institute of Scientific and Technical Information of China (English)

    XUE Chunting; Russell Howorth

    2003-01-01

    Three types of natural connection between atoll islets are described. Causeway, as an artificial way of connecting islets, makes a connection to be completed in a few months. In this case shore adjustment becomes more vigorous than that in natural conditions, resulting in lagoon shore erosion. A causeway without short bridges or culverts should be built close to the lagoon shore to reduce lagoon shore erosion. A causeway-crossing channel assemblage is the worst type among all of the connection engineering constructions because the crossing channel traps sediment and further transports it out of the channel, resulting in long period coastal erosion. Reforming Nippon Causeway in Tarawa Atoll, Kiribati by simple means will stop sand loss, reduce shore erosion and greatly upgrade its stability.

  7. 76 FR 40751 - National Environmental Policy Act; Wallops Flight Facility; Site-Wide

    Science.gov (United States)

    2011-07-11

    ... From the Federal Register Online via the Government Publishing Office NATIONAL AERONAUTICS AND...: National Aeronautics and Space Administration. ACTION: Notice of intent to prepare a Site-wide Programmatic... Wallops Island; replacement of the Wallops causeway bridge; maintenance dredging between the boat docks...

  8. 78 FR 33400 - Free Flow Power Corporation; Notice Soliciting Scoping Comments

    Science.gov (United States)

    2013-06-04

    ... Energy Regulatory Commission Free Flow Power Corporation; Notice Soliciting Scoping Comments Take notice... filed: December 3, 2012. d. Applicant: Free Flow Power Corporation (Free Flow Power), on behalf of its...: Ramya Swaminathan, Chief Operating Officer, Free Flow Power Corporation, 239 Causeway Street, Suite...

  9. 78 FR 4070 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway and Biscayne Bay, Miami, FL

    Science.gov (United States)

    2013-01-18

    ... Biscayne Bay, Miami, FL AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviations from regulations... the following two bridges in Miami, Florida: The Venetian Causeway Bridge (West), mile 1088.6, across... deviations are necessary due to the high volume of vessel and vehicle traffic anticipated during the...

  10. 77 FR 4247 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway and Biscayne Bay, Miami, FL

    Science.gov (United States)

    2012-01-27

    ... Biscayne Bay, Miami, FL AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviations from regulations... governing the operation of the following two bridges in Miami, Florida: The Venetian Causeway Bridge (West... because of the Miami International Boat Show. These deviations will result in the bridges only opening...

  11. 77 FR 55693 - Safety Zone; Miami Paddle Challenge, Biscayne Bay, Miami, FL

    Science.gov (United States)

    2012-09-11

    ... DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA08 Safety Zone; Miami Paddle Challenge, Biscayne Bay, Miami... Causeway in Miami, Florida during the Miami Paddle Challenge, a series of paddle boat races. The...

  12. 77 FR 75553 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Biscayne Bay, and Miami River...

    Science.gov (United States)

    2012-12-21

    ..., Biscayne Bay, and Miami River, Miami, FL AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviations... governing the operation of the following four bridges in Miami, Florida: The Venetian Causeway Bridge (West... Biscayne Bay; the Miami Avenue Bridge, mile 0.3, across the Miami River; and the Brickell Avenue...

  13. Density-stratified flow events in Great Salt Lake, Utah, USA: implications for mercury and salinity cycling

    Science.gov (United States)

    Naftz, David L.; Carling, Gregory T.; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Pazmiño, Eddy

    2014-01-01

    Density stratification in saline and hypersaline water bodies from throughout the world can have large impacts on the internal cycling and loading of salinity, nutrients, and trace elements. High temporal resolution hydroacoustic and physical/chemical data were collected at two sites in Great Salt Lake (GSL), a saline lake in the western USA, to understand how density stratification may influence salinity and mercury (Hg) distributions. The first study site was in a causeway breach where saline water from GSL exchanges with less saline water from a flow restricted bay. Near-surface-specific conductance values measured in water at the breach displayed a good relationship with both flow and wind direction. No diurnal variations in the concentration of dissolved (total and MeHg loadings was observed during periods of elevated salinity. The second study site was located on the bottom of GSL where movement of a high-salinity water layer, referred to as the deep brine layer (DBL), is restricted to a naturally occurring 1.5-km-wide “spillway” structure. During selected time periods in April/May, 2012, wind-induced flow reversals in a railroad causeway breach, separating Gunnison and Gilbert Bays, were coupled with high-velocity flow pulses (up to 55 cm/s) in the DBL at the spillway site. These flow pulses were likely driven by a pressure response of highly saline water from Gunnison Bay flowing into the north basin of Gilbert Bay. Short-term flow reversal events measured at the railroad causeway breach have the ability to move measurable amounts of salt and Hg from Gunnison Bay into the DBL. Future disturbance to the steady state conditions currently imposed by the railroad causeway infrastructure could result in changes to the existing chemical balance between Gunnison and Gilbert Bays. Monitoring instruments were installed at six additional sites in the DBL during October 2012 to assess impacts from any future modifications to the railroad causeway.

  14. Holocene morphogenesis of Alexander the Great's isthmus at Tyre in Lebanon

    OpenAIRE

    Marriner, Nick; Morhange, Christophe; Meulé, Samuel

    2007-01-01

    In 332 B.C., Alexander the Great constructed an ≈1,000-m-long causeway to seize the offshore island of Tyre. The logistics behind this engineering feat have long troubled archaeologists. Using the Holocene sedimentary record, we demonstrate that Alexander's engineers cleverly exploited a shallow proto-tombolo, or sublittoral sand spit, to breach the offshore city's defensive impregnability. We elucidate a three-phase geomorphological model for the spit's evolution. Settled since the Bronze Ag...

  15. Tidal dynamics in a frictionally dominated tropical lagoon

    Science.gov (United States)

    Tenorio-Fernandez, L.; Gomez-Valdes, J.; Marino-Tapia, I.; Enriquez, C.; Valle-Levinson, A.; Parra, S. M.

    2016-02-01

    This study examined the dynamics of tidal propagation inside a tropical lagoon. Sea surface elevation (inside) and current profiles (at the inlet) were examined over 60 days at the Chelem lagoon, which is a branched tropical lagoon located in the northern Yucatan Peninsula. Tides were predominantly diurnal with a wavelength at least 20 times longer than the total length of the basin. Spatial variations of sea surface elevation and the longitudinal transport were described in each branch by applying a linear analytical model and the results were compared to observations. Results showed that the coastal lagoon was highly frictional. The tidal signal was attenuated between 30% and 40% toward the lagoon heads, a result of the balance between pressure gradient and frictional forces. A causeway that chokes the western side of the lagoon allowed the propagation of the diurnal signal toward the west head of the basin but damped the semidiurnal signal. The causeway acted as a hydraulic low-pass filter, as in natural choked systems. The causeway's filter effect was included in the analytical model by optimizing the frictional parameters.

  16. Non-proportional bioaccumulation of trace metals and metalloids in the planktonic food web of two Singapore coastal marine inlets with contrasting water residence times.

    Science.gov (United States)

    Calbet, Albert; Schmoker, Claire; Russo, Francesca; Trottet, Aurore; Mahjoub, Mohamed-Sofiane; Larsen, Ole; Tong, Hor Yee; Drillet, Guillaume

    2016-08-01

    We analyzed the concentrations of trace metals/metalloids (TMs) in the water, sediment and plankton of two semi-enclosed marine coastal inlets located north of Jurong Island and separated by a causeway (SW Singapore; May 2012-April 2013). The west side of the causeway (west station) has residence times of approximately one year, and the east side of the causeway (east station) has residence times of one month. The concentrations of most of the TMs in water and sediment were higher in the west than in the east station. In the water column, most of the TMs were homogeneously distributed or had higher concentrations at the surface. Preliminary evidence suggests that the TMs are primarily derived from aerosol depositions from oil combustion and industry. Analyses of TMs in seston (>0.7μm; mostly phytoplankton) and zooplankton (>100μm) revealed that the seston from the west station had higher concentrations of most TMs; however, the concentrations of TMs in zooplankton were similar at the two stations. Despite the high levels of TMs in water, sediment and seston, the bioaccumulation detected in zooplankton was moderate, suggesting either the presence of effective detoxification mechanisms or/and the inefficient transfer of TMs from primary producers to higher trophic levels as a result of the complexity of marine planktonic food webs. In summary, the TM concentrations in water and seston are not reliable indicators of the bioaccumulation at higher trophic levels of the food web. PMID:27104581

  17. Przemiany stosunków wodnych w dolinie górnej Noteci do połowy XIX wieku związane z antropopresją

    OpenAIRE

    Kaniecki, Alfred

    2011-01-01

    The start of the great drainage work in the Upper Noteć valley is connected with the construction of the Bydgoszcz Canal in the years 1772–1774. Earlier, the economic ventures, like building of water mills or causeways, affected the area water conditions only locally. A reconstruction of the initial look of the valley still rests on historical source materials because no research has been conducted in the region to date. Here, we made use of the information from the 15th-century chronicle by ...

  18. Masdar City: a critical retrospection

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2014-01-01

    infrastructure such as global container ports, free zones, inter-island causeways and metro lines. This volume argues that these endeavours are not simply part of a strategy to prepare for the post-oil era for future economic survival and prosperity in the Lower Gulf region, but that they are also aiming...... Dubai appeared - at least until the financial crisis - to be leading the construction race and has already completed a large number of its landmark architecture and strategic facilities. In contrast, cities like the Qatari capital Doha still appear to be heavily ‘under construction’ and in countries...

  19. Architecture, cobbled roads and chronology of the main sector of the site Las Mercedes-1, Central Caribbean of Costa Rica

    International Nuclear Information System (INIS)

    Results from test-pit excavations, survey, and mapping at Las Mercedes-1, plus the center of a paramount chiefly polity in the Central Caribbean region of Costa Rica, are presented. Information on architecture, construction system, ceramic chronology, and funerary features, are reported. Radiocarbon dates have suggested that important construction works at the site's center were carried out circa A.D. 1000. Two cobble-paved, causeways, perpendicular to the river drainage system, were found to be linked to the main monumental compound as roads for formal access. Interest in the site has been revived and points the way to further researches at the site and its regional sphere. (author)

  20. Holocene morphogenesis of Alexander the Great's isthmus at Tyre in Lebanon

    Science.gov (United States)

    Marriner, Nick; Morhange, Christophe; Meulé, Samuel

    2007-05-01

    In 332 B.C., Alexander the Great constructed an ≈1,000-m-long causeway to seize the offshore island of Tyre. The logistics behind this engineering feat have long troubled archaeologists. Using the Holocene sedimentary record, we demonstrate that Alexander's engineers cleverly exploited a shallow proto-tombolo, or sublittoral sand spit, to breach the offshore city's defensive impregnability. We elucidate a three-phase geomorphological model for the spit's evolution. Settled since the Bronze Age, the area's geological record manifests a long history of natural and anthropogenic forcings. (i) Leeward of the island breakwater, the maximum flooding surface (e.g., drowning of the subaerial land surfaces by seawater) is dated ≈8000 B.P. Fine-grained sediments and brackish and marine-lagoonal faunas translate shallow, low-energy water bodies at this time. Shelter was afforded by Tyre's elongated sandstone reefs, which acted as a 6-km natural breakwater. (ii) By 6000 B.P., sea-level rise had reduced the dimensions of the island from 6 to 4 km. The leeward wave shadow generated by this island, allied with high sediment supply after 3000 B.P., culminated in a natural wave-dominated proto-tombolo within 1-2 m of mean sea level by the time of Alexander the Great (4th century B.C.). (iii) After 332 B.C., construction of Alexander's causeway entrained a complete anthropogenic metamorphosis of the Tyrian coastal system.

  1. Effects of eutrophication on the planktonic food web dynamics of marine coastal ecosystems: The case study of two tropical inlets.

    Science.gov (United States)

    Schmoker, Claire; Russo, Francesca; Drillet, Guillaume; Trottet, Aurore; Mahjoub, Mohamed-Sofiane; Hsiao, Shih-Hui; Larsen, Ole; Tun, Karenne; Calbet, Albert

    2016-08-01

    We studied the plankton dynamics of two semi-enclosed marine coastal inlets of the north of Jurong Island separated by a causeway (SW Singapore; May 2012-April 2013). The west side of the causeway (west station) has residence times of ca. one year and is markedly eutrophic. The east side (east station) has residence times of one month and presents lower nutrient concentrations throughout the year. The higher nutrient concentrations at the west station did not translate into significantly higher concentrations of chlorophyll a, with the exception of some peaks at the end of the South West Monsoon. Microzooplankton were more abundant at the west station. The west station exhibited more variable abundances of copepods during the year than did the east station, which showed a more stable pattern and higher diversity. Despite the higher nutrient concentrations at the west station (never limiting phytoplankton growth), the instantaneous phytoplankton growth rates there were generally lower than at the east station. The phytoplankton communities at the west station were top-down controlled, largely by microzooplankton grazing, whereas those of the east station alternated between top-down and bottom-up control, with mesozooplankton being the major grazers. Overall, the trophic transfer efficiency from nutrients to mesozooplankton in the eutrophic west station was less efficient than in the east station, but this was mostly because a poor use of inorganic nutrients by phytoplankton rather than an inefficient trophic transfer of carbon. Some hypotheses explaining this result are discussed. PMID:27326462

  2. Three dimensional model evaluation of physical alterations of the Caloosahatchee River and Estuary: Impact on salt transport

    Science.gov (United States)

    Sun, Detong; Wan, Yongshan; Qiu, Chelsea

    2016-05-01

    Numerical hydrodynamic modeling provides quantitative understanding of how physical alterations of an estuary may alter the waterbody hydrodynamics and the rate of mixing with the ocean. In this study, a three dimensional hydrodynamic model (CH3D) was used to compare simulated salinities between the existing condition and five historical cases representing varying physical alterations of the Caloosahatchee Estuary involving (1) removal of the headwater structure (S-79); (2) removal of the downstream causeway to Sanibel Island; (3) backfilling an oyster bar near the estuary month; (4) refilling the navigation channel; and (5) the pre-development bathymetric condition. The results suggested that some alterations including the Sanibel Causeway, backfilling the oyster bar and the S-79 structure may have some local effects but did not change estuarine salinity structure significantly. Refilling the navigation channel had a more profound effect, resulting in a dry season salinity reduction of about 5 when compared with the existing condition. The reduced salt transport was more pronounced with the pre-development bathymetry because the estuary as a whole was much shallower than today. The significant system-wide increase in salt transport caused by the historic dredging of the navigation channel in the Caloosahatchee Estuary has significant implications in the development of attainable environmental flow targets for protecting the estuarine ecosystem.

  3. Risk factors and spatial distribution of Schistosoma mansoni infection among primary school children in Mbita District, Western Kenya.

    Directory of Open Access Journals (Sweden)

    Sachiyo Nagi

    2014-07-01

    Full Text Available An increasing risk of Schistosoma mansoni infection has been observed around Lake Victoria, western Kenya since the 1970s. Understanding local transmission dynamics of schistosomiasis is crucial in curtailing increased risk of infection.We carried out a cross sectional study on a population of 310 children from eight primary schools. Overall, a total of 238 (76.8% children were infected with S. mansoni, while seven (2.3% had S. haematobium. The prevalence of hookworm, Trichuris trichiura and Ascaris lumbricoides were 6.1%, 5.2% and 2.3%, respectively. Plasmodium falciparum was the only malaria parasite detected (12.0%. High local population density within a 1 km radius around houses was identified as a major independent risk factor of S. mansoni infection. A spatial cluster of high infection risk was detected around the Mbita causeway following adjustment for population density and other potential risk factors.Population density was shown to be a major factor fuelling schistosome infection while individual socio-economic factors appeared not to affect the infection risk. The high-risk cluster around the Mbita causeway may be explained by the construction of an artificial pathway that may cause increased numbers of S. mansoni host snails through obstruction of the waterway. This construction may have, therefore, a significant negative impact on the health of the local population, especially school-aged children who frequently come in contact with lake water.

  4. Hydrogeochemistry of seasonal variation of Urmia Salt Lake, Iran.

    Science.gov (United States)

    Alipour, Samad

    2006-01-01

    Urmia Lake has been designated as an international park by the United Nations. The lake occupies a 5700 km2 depression in northwestern Iran. Thirteen permanent rivers flow into the lake. Water level in the lake has been decreased 3.5 m in the last decade due to a shortage of precipitation and progressively dry climate. Geologically the lake basin is considered to be a graben of tectonic origin. Na, K, Ca, Li and Mg are the main cations with Cl, SO4, and HCO3 as the main anions. F & Br are the other main elements in the lake. A causeway crossing the lake is under construction, which may affect the lake's annual geochemistry. The main object of this project is mainly to consider the potential of K-mineral production along with ongoing salt production. Seven hundred and four samples were taken and partially analyzed for the main cations and anions. Surface water (0.5 m. depth) was analyzed for Na, K, Mg, Ca, Br and Li, and averaged 87.118 g/lit, 1.48 g/lit, 4.82 g/lit, 4.54 g/lit, 1.19 ppm and 12.7 ppm respectively for the western half of the lake. Sodium ranged between 84 to 91.2 g/lit, and showed higher concentrations in the south than in the north. This unexpected result may be caused by shallower depth in the south and a higher net evaporation effect. Calcium ranged between 4.2 to 5 g/lit, apparently slightly higher in the north. K is higher in the south, possibly due to rivers entering from south that may carry slightly higher K in solution. In the middle-range samples (0.5-5 m.), K averaged 1.43 g/lit and ranged from 1.40 to 1.46 g/lit. At this intermediate depth the distribution of K is clearly higher to the south of the causeway that is currently under construction. It is not clear whether this increase is the effect of the causeway or the effect of the salty Aji-Chay River to the east, and the Khoy salt domes to the north of the lake. At depth (5 m-10 m), K averaged 1.48 g/lit and ranged from 1.4 to 1.49 g/lit, differing only in the second decimal from the

  5. Alexander the Great's tombolos at Tyre and Alexandria, eastern Mediterranean

    Science.gov (United States)

    Marriner, N.; Goiran, J. P.; Morhange, C.

    2008-08-01

    Tyre and Alexandria's coastlines are today characterised by wave-dominated tombolos, peculiar sand isthmuses that link former islands to the adjacent continent. Paradoxically, despite a long history of inquiry into spit and barrier formation, understanding of the dynamics and sedimentary history of tombolos over the Holocene timescale is poor. At Tyre and Alexandria we demonstrate that these rare coastal features are the heritage of a long history of natural morphodynamic forcing and human impacts. In 332 BC, following a protracted seven-month siege of the city, Alexander the Great's engineers cleverly exploited a shallow sublittoral sand bank to seize the island fortress; Tyre's causeway served as a prototype for Alexandria's Heptastadium built a few months later. We report stratigraphic and geomorphological data from the two sand spits, proposing a chronostratigraphic model of tombolo evolution.

  6. The pursuit of perfect packing

    CERN Document Server

    Weaire, Denis

    2000-01-01

    In 1998 Thomas Hales dramatically announced the solution of a problem that has long teased eminent mathematicians: what is the densest possible arrangement of identical spheres? The Pursuit of Perfect Packing recounts the story of this problem and many others that have to do with packing things together. The examples are taken from mathematics, physics, biology, and engineering, including the arrangement of soap bubbles in foam, atoms in a crystal, the architecture of the bee''s honeycomb, and the structure of the Giant''s Causeway. Using an informal style and with key references, the book also includes brief accounts of the lives of many of the scientists who devoted themselves to problems of packing over many centuries, together with wry comments on their efforts. It is an entertaining introduction to the field for both specialists and the more general public.

  7. Use of an Acoustic Doppler Current Profiler (ADCP) to Measure Hypersaline Bidirectional Discharge

    Science.gov (United States)

    Johnson, K.K.; Loving, B.L.; ,

    2002-01-01

    The U.S. Geological Survey measures the exchange of flow between the north and south parts of Great Salt Lake, Utah, as part of a monitoring program. Turbidity and bidirectional flow through the breach in the causeway that divides the lake into two parts makes it difficult to measure discharge with conventional streamflow techniques. An acoustic Doppler current profiler (ADCP) can be used to more accurately define the angles of flow and the location of the interface between the layers of flow. Because of the high salinity levels measured in Great Salt Lake (60-280 parts per thousand), special methods had to be developed to adjust ADCP-computed discharges for the increased speed of sound in hypersaline waters and for water entrained at the interface between flow layers.

  8. The architectonic encoding of the minor lunar standstills in the horizon of the Giza pyramids.

    Science.gov (United States)

    Hossam, M. K. Aboulfotouh

    The paper is an attempt to show the architectonic method of the ancient Egyptian designers for encoding the horizontal-projections of the moon's declinations during two events of the minor lunar standstills, in the design of the site-plan of the horizon of the Giza pyramids, using the methods of descriptive geometry. It shows that the distance of the eastern side of the second Giza pyramid from the north-south axis of the great pyramid encodes a projection of a lunar declination, when earth's obliquity-angle was ~24.10°. Besides, it shows that the angle of inclination of the causeway of the second Giza pyramid, of ~13.54° south of the cardinal east, encodes the projection of another lunar declination when earth's obliquity-angle reaches ~22.986°. In addition, it shows the encoded coordinate system in the site-plan of the horizon of the Giza pyramids.

  9. Las Pozas (Casaseca de las Chanas, Zamora: dos nuevos recintos de fosos calcolíticos en el Valle del Duero

    Directory of Open Access Journals (Sweden)

    García García, Marcos

    2013-06-01

    Full Text Available Since 1975 the site of Las Pozas has given its name to the prebeaker horizon in the Spanish Northern Plateau. In the last decade several causewayed enclosures dated to this period have been discovered. This new situation has led us to revise the foundation site using remote sensing techniques. The infrared images have allowed us to distinguish two overlapping enclosures at Las Pozas: a north one with three interrupted ditches and a southern group composed of two circles. This paper describes the characteristics of both enclosures using as well the information provided by the 1979 and 1987 excavations. We believe this discovery certifies that causewayed enclosures were a common feature in the Douro Valley during the Copper Age.Desde 1975 el yacimiento de Las Pozas ha dado nombre al horizonte precampaniforme de la Submeseta Norte de la Península Ibérica. En la última década se han localizado varios recintos de fosos adscritos a este periodo que han motivado una revisión del yacimiento fundacional utilizando técnicas de teledetección. Las imágenes de infrarrojo han permitido distinguir en Las Pozas dos recintos de fosos superpuestos: el septentrional con tres líneas de foso y el meridional con dos. En este artículo se describen las características de ambos empleando la información revelada por las excavaciones de 1979 y 1987. Consideramos que el hallazgo certifica que este tipo de yacimientos no son una excepción en el Calcolítico del Valle del Duero.

  10. Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004

    Science.gov (United States)

    Nentwig, Vanessa; Bahlburg, Heinrich; Monthy, Devis

    2015-03-01

    The Seychelles, an archipelago in the Indian Ocean at a distance of 4,500-5,000 km from the west coast of Sumatra, were severely affected by the December 26, 2004 tsunami with wave heights up to 4 m. Since the tsunami history of small islands often remains unclear due to a young historical record, it is important to study the geological traces of high energy events preserved along their coasts. We conducted a survey of the impact of the 2004 Indian Ocean tsunami on the inner Seychelles islands. In detail we studied onshore tsunami deposits in the mangrove forest at Old Turtle Pond in the Curieuse Marine National Park on the east coast of Curieuse Island. It is thus protected from anthropogenic interference. Towards the sea it was shielded until the tsunami in 2004 by a 500 m long and 1.5 m high causeway which was set up in 1909 as a sediment trap and assuring a low energetic hydrodynamic environment for the protection of the mangroves. The causeway was destroyed by the 2004 Indian Ocean Tsunami. The tsunami caused a change of habitat by the sedimentation of sand lobes in the mangrove forest. The dark organic rich mangrove soil (1.9 Φ) was covered by bimodal fine to medium carbonate sand (1.7-2.2 Φ) containing coarser carbonate shell fragments and debris. Intertidal sediments and the mangrove soil acted as sources of the lobe deposits. The sand sheet deposited by the tsunami is organized into different lobes. They extend landwards to different inundation distances as a function of the morphology of the onshore area. The maximum extent of 180 m from the shoreline indicates the minimum inundation distance to the tsunami. The top parts of the sand lobes cover the pneumatophores of the mangroves. There is no landward fining trend along the sand lobes and normal grading of the deposits is rare, occurring only in 1 of 7 sites. The sand lobe deposits also lack sedimentary structures. On the surface of the sand lobes numerous mostly fragmented shells of bivalves and

  11. The Writing on the Wall: National and Global Implications of the Ruling Chinese Communist Party’s Domestic and Foreign Policies

    Directory of Open Access Journals (Sweden)

    Emile Kok-Kheng Yeoh

    2016-04-01

    Full Text Available The December 2015 crackdown on labour activists was the culmination of a year of the Chinese Communist Party regime’s war on China’s civil society kicked off with the arrests of the “Feminist Five” in March, followed by the infamous crackdown on civil rights lawyers that began on 5th July and lasted till August. At around the same time, from mid-October to end of December 2015, five owners and staff members of Hong Kong’s Mighty Current publishing company and Causeway Bay bookshop which respectively publishes and sells politically dissident books banned by China disappeared under mysterious circumstances (including one while vacationing in Pattaya, Thailand, and another while inspecting warehouse in Hong Kong and reemerged in mainland China under the custody of the Chinese authorities. While these volatile incidents were unfolding domestically, the year also witnessed the continued rise of China’s economic might in the global system. With specific focus on the latest events unfolding from year 2015 to the present, this paper attempts to interpret such developments especially in terms of government policies with respect to the State’s relations with the civil society since the leadership transition from Hu-Wen to Xi-Li administration, the implications of the global reach of China’s economic might and soft power in this regard, as well as the current nature of the governing regime of the Chinese Communist Party.

  12. Discovering the Ancient Maya from Space

    Science.gov (United States)

    Sever, T. L.

    2008-01-01

    The Pet6n region of northern Guatemala contains some of the most significant Mayan archeological sites in Latin America. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper, IKONOS, and QuickBird satellite, and airborne STAR-3i and AIRSAR radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as sites, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the bajos, which are seasonally flooded swamps that cover over 40% of the land surface. Through the use of various airborne and satellite sensor systems we have been able to detect and map ancient causeways, temples, reservoirs, and land forms, and locate these features on the ground through GPS technology. Recently, we have discovered that there is a strong relationship between a tropical forest vegetation signature in satellite imagery and the location of archeological sites. We believe that the use of limestone and lime plasters in ancient Maya construction affects the moisture, nutrition, and plant species of the surface vegetation. We have mapped these vegetation signatures in the imagery and verified through field survey that they are indicative of archeological sites. Through the use of remote sensing and GIS technology it is possible to identify unrecorded archeological features in a dense tropical forest environment and monitor these cultural features for their protection.

  13. Google Earth: Inspiration and Instrument for the Study of Ancient Civilizations

    Directory of Open Access Journals (Sweden)

    Jaroslav Klokočník

    2011-12-01

    Full Text Available Satellite imaging is well known as a useful tool in many scientific disciplines and various applications.  Google Earth, with its free access, is now - thanks to increasing resolution and precision - such a tool. It can be very inspiring. It improves the visualization and dissemination of scientific data, and opens doors to new discoveries. For example, many Nasca geoglyphs are now visible to Google Earth and so are the orientations of Chinese pyramids, which appear to be laid out with the aid of a magnetic compass. Google Earth also infor-med us about the “new” archaeological locality Atzompa close to the well known “Monte Alban” near Oaxaca (Mexico, which we then visited (in March 2010. Google Earth can also “see” prehistoric causeways in Mesoamerica, “sacbeob” and in the Chaco valley (New Mexico. We find that Google Earth can save time and resources to researches significantly: before, during and after field works and measurements; we present examples.

  14. An evaluation of temporal changes in sediment accumulation and impacts on carbon burial in Mobile Bay, Alabama, USA

    Science.gov (United States)

    Smith, Christopher G.; Osterman, Lisa E.

    2014-01-01

    The estuarine environment can serve as either a source or sink of carbon relative to the coastal ocean carbon budget. A variety of time-dependent processes such as sedimentation, carbon supply, and productivity dictate how estuarine systems operate, and Mobile Bay is a system that has experienced both natural and anthropogenic perturbations that influenced depositional processes and carbon cycling. Sediments from eight box cores provide a record of change in bulk sediment accumulation and carbon burial over the past 110 years. Accumulation rates in the central part of the basin (0.09 g cm−2) were 60–80 % less than those observed at the head (0.361 g cm−2) and mouth (0.564 g cm−2) of the bay. Sediment accumulation in the central bay decreased during the past 90 years in response to both anthropogenic (causeway construction) and natural (tropical cyclones) perturbations. Sediment accumulation inevitably increased the residence time of organic carbon in the oxic zone, as observed in modeled remineralization rates, and reduced the overall carbon burial. Such observations highlight the critical balance among sediment accumulation, carbon remineralization, and carbon burial in dynamic coastal environments. Time-series analysis based solely on short-term observation would not capture the long-term effects of changes in sedimentation on carbon cycling. Identifying these relationships over longer timescales (multi-annual to decadal) will provide a far better evaluation of coastal ocean carbon budgets.

  15. Overseas Voter Mobilisation in Singapore: Implications from Malaysia’s 13th General Election

    Directory of Open Access Journals (Sweden)

    James Gomez

    2013-01-01

    Full Text Available This paper discusses voter mobilisation and other election-related activities of Malaysian voters living, studying and working in Singapore in the context of Malaysia’s 13th general election (GE13. According to the World Bank, nearly 400,000 Malaysians reside in the city-state. Thus these figures represent a significant Malaysian voter pool based in Singapore. Efforts to mobilise these voters for general elections or other causes have political implications for both countries, which became apparent following Singapore-based Malaysians’ activities to encourage Malaysians to return home to cast their votes during the 13th general election. Singapore’s strict public assembly laws led to several legal issues related to the voter mobilisation and election campaign activities undertaken by Malaysians in the city-state. These legal issues became a source of friction between the two countries during the elections as government leaders and authorities on both sides of the causeway accused the other of interfering in domestic political matters. Given the growing number of Malaysians in Singapore and the likely repeat of Malaysian voter mobilisation activities in Singapore in the run-up to the fourteenth general election (GE14 in 2018, issues related to the election activities of Malaysian voters in Singapore stand to be another set of factors that will shape the health of bilateral relations between these two countries.

  16. Summary of 1987 and 1988 manatee aerial surveys at Kennedy Space Center

    Science.gov (United States)

    Provancha, Jane A.; Provancha, Mark J.

    1989-01-01

    Aerial surveys of manatees conducted since 1977 at Kennedy Space Center (KSC) have provided a very useful and cost effective monitoring tool in the assessment of abundance and distribution of manatees in the northern Banana River. Data collected in the mid 1980's as part of the KSC Environmental Monitoring Program indicated that the numbers of manatees utilizing the northern Banana River had increased dramatically from earlier years and that the animals appeared to have changed their distribution patterns within the area as well (Provancha and Provancha 1988). United States Fish and Wildlife Service (USFWS) and Florida Department of Natural Resources (FLDNR) conducted bimonthly aerial surveys in 1986 for the entire Florida east coast. Their data clearly show that the Banana River has the highest concentration of manatees during the non-winter months when compared to all other segments of the east coast surveys (B. Wiegle/FLDNR, unpublished data). They further show that, in spring, an average of 71 percent of the manatees in Brevard county were located in the Banana River. During that period 85 percent of the animals were north of the NASA Causeway (State Road (SR) 402) in the KSC security zone. These data indicate the importance of the KSC waters to the Florida east coast manatee population. We reinitiated KSC surveys in 1987 to document distributions and numbers of manatees during the spring influx. Aerial censuses were continued throughout the year in 1988 and this report provides a summary of our findings for the two years.

  17. The Writing on the Wall: National and Global Implications of the Ruling Chinese Communist Party’s Domestic and Foreign Policies

    Directory of Open Access Journals (Sweden)

    Emile Kok-Kheng Yeoh

    2016-04-01

    Full Text Available The December 201 5 crackdown on labour activists was the culmination of a year of the Chinese Communist Party regime’s war on China’s civil society kicked off by of the arrests of the “Feminist Five” in March followed by the infamous crackdown on civil rights lawyers that began on 5th July and lasted till August. At around the same time, from mid-October to end of December 2015, five owners and staff members of Hong Kong’s Mighty Current publishing company and Causeway Bay bookshop which respectively publishes and selling politically dissident books banned by China disappeared under mysterious circumstances (including one while vacationing in Pattaya, Thailand, and another while inspecting warehouse in Hong Kong and reemerged in mainland China under the custody of the Chinese authorities. While these volatile incidents were unfolding domestically, the year also witnessed the continued rise of China’s economic might in the global system. With specific focus on the latest events unfolding from year 2015 to the present, this paper attempts to interpret such developments especially in terms of government policies with respect to the State’s relations with the civil society since the leadership transition from Hu-Wen to Xi-Li administration, the implications of the global reach of China’s economic might and soft power in this regard, as well as the current nature of the governing regime of the Chinese Communist Party.

  18. Foreword – Upon the Second Anniversary of Occupy Campaign / Umbrella Movement in Hong Kong: Essays in Honour of a Pro-Democracy Sociopolitical Movement

    Directory of Open Access Journals (Sweden)

    Emile Kok-Kheng Yeoh

    2016-08-01

    Full Text Available 28th September 2016 is the second anniversary of the Occupy Campaign / Umbrella Movement in Hong Kong. It is also the last anniversary of the said sociopolitical event, which arguably represented a most important milestone in Hong Kong’s post-1997 development, before 1st July 2017 that will mark the 20th anniversary of the “Handover”. It was on 28th September two years ago that pro-democracy protestors occupy the Admiralty, Causeway Bay, Mong Kok and Tsim Sha Tsui areas of Hong Kong in a momentous campaign initially planned out earlier by the “Occupy Central with Love and Peace” (OCLP movement, but launched earlier than scheduled when overtaken by the development of events, metamorphosed into unprecedented scale of demonstrations at multiple locations and was transformed into what was dubbed by the world media as the “Umbrella Movement” when umbrellas, which protestors were using to protect themselves when the police attacked them with tear gas and pepper spray, became a symbol of the occupation campaign. To commemorate this second anniversary of this Occupy Campaign a.k.a. Umbrella Movement, the present issue of Contemporary Chinese Political Economy and Strategic Relations: An International Journal entitled From Handover to Occupy Campaign: Democracy, Identity and the Umbrella Movement of Hong Kong represents a collection of specially selected articles focusing on this momentous event, its background of determining factors, theoretical and ideological underpinnings, as well as its implications for the future of the Hong Kong people’s valiant struggle for democracy against the backdrop of the formidable odds, since the 1997 “Handover”, as being under the sovereignty of a gigantic country with a entrenched ruling Chinese Communist Party (CCP6 regime that has no foreseeable intention of allowing for a transition from the present repressive one-party dictatorship to liberal democracy that would respect political freedom and

  19. Socioeconomic impacts and management ciguatera in the Pacific.

    Science.gov (United States)

    Lewis, R J

    1992-01-01

    population, pollution and development (e.g. causeways) pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Eco-engineered rock pools: a concrete solution to biodiversity loss and urban sprawl in the marine environment

    Science.gov (United States)

    Firth, Louise B.; Browne, Keith A.; Knights, Antony M.; Hawkins, Stephen J.; Nash, Róisín

    2016-09-01

    In coastal habitats artificial structures typically support lower biodiversity and can support greater numbers of non-native and opportunistic species than natural rocky reefs. Eco-engineering experiments are typically trialed to succeed; but arguably as much is learnt from failure than from success. Our goal was to trial a generic, cost effective, eco-engineering technique that could be incorporated into rock armouring anywhere in the world. Artificial rock pools were created from manipulated concrete between boulders on the exposed and sheltered sides of a causeway. Experimental treatments were installed in locations where they were expected to fail and compared to controls installed in locations in which they were expected to succeed. Control pools were created lower on the structure where they were immersed on every tidal cycle; experimental pools were created above mean high water spring tide which were only immersed on spring tides. We hypothesised that lower and exposed pools would support significantly higher taxon and functional diversity than upper and sheltered pools. The concrete pools survived the severe winter storms of 2013/14. After 12 months, non-destructive sampling revealed significantly higher mean taxon and functional richness in lower pools than upper pools on the exposed side only. After 24 months the sheltered pools had become inundated with sediments, thus failing to function as rock pools as intended. Destructive sampling on the exposed side revealed significantly higher mean functional richness in lower than upper pools. However, a surprisingly high number of taxa colonised the upper pools leading to no significant difference in mean taxon richness among shore heights. A high number of rare taxa in the lower pools led to total taxon richness being almost twice that of upper pools. These findings highlight that even when expected to fail concrete pools supported diverse assemblages, thus representing an affordable, replicable means of

  1. Lake Urmia Shrinkage and its Effect on the Settlement of the Surrounding Areas Investigated Using Radar and Optical Satellite Images

    Science.gov (United States)

    Motagh, M.; Shamshiri, R.; Hosseini, F.; Sharifi, M. A.; Baes, M.

    2014-12-01

    With a total area of more than 50000 km^2 Lake Urmia basin in northwest of Iran was once one of the biggest salt lakes in the world. The lake has been shrinking in the recent years, losing in turn dramatically its area. A lot of factors have been attributed to this shrinking including construction of dams on the rivers feeding the lake and overexploitation of groundwater for agricultural and industrial purposes. In this study we first utilized time-series analysis of Landsat images to precisely quantify surface changes in the region between 1984 and 2013. We then analyzed a number of SAR images from 2002 to 2014 including 30 ASAR images from Envisat, 10 PALSAR images from ALOS, and more than 35 TerraSAR-X (TSX) in both Stripmap and Spot modes to assess surface ground deformation. Ground deformation was evaluated for both agricultural regions around the lake and Lake Urmia Causeway (LUC), connecting two provinces of East and West Azerbaijan on both sides of the lake. The InSAR results of the LUC embankments is further investigated using Finite Element approach to better understand the relation between soil parameters, lake level changes and settlement of the LUC. The classification results using optical imagery analysis show that human and anthropogenic activities have resulted in shrinking of Lake Urmia by more than 60% over the past 30 years. The agricultural areas around the lake are dominated by ground subsidence reaching to 10 cm/yr in places. The LUC embankments also show large deformation with peak settlement of more than 5 cm/yr over the last decade. FEM simulation shows that consolidation due to dissipation of excess pore pressure in embankments can satisfactorily explain its surface deformation.

  2. EL DESCUBRIMIENTO DE UN CEMENTERIO DE ÉLITE EN EL CAÑO: INDICIOS DE UN PATRÓN FUNERARIO EN EL VALLE DE RÍO GRANDE, COCLÉ, PANAMÁ (The Discovery of an Elite Cemetery at El Caño: Traces of a Mortuary Pattern in Río Grande Valley, Coclé, Panama

    Directory of Open Access Journals (Sweden)

    Julia Mayo

    2013-11-01

    Full Text Available El Caño, situado en la provincia de Coclé (Panamá, es un yacimiento arqueológico conocido por su singular estilo escultórico y por contener estructuras arqueológicas de piedra. Recientemente se han descubierto en este lugar cuatro tumbas de personas de élite con ricos ajuares, fechadas entre el 700 y el 1000 d. C. Estas son coetáneas a las halladas en el cercano Sitio Conte, una necrópolis en la que se encontraron, hace más de ochenta años, las primeras evidencias arqueológicas de la complejidad de las sociedades precolombinas del istmo. La existencia en Sitio Conte y El Caño de elementos semejantes —basaltos columnarios dispuestos en hileras, calzadas y ricas tumbas— organizados además de forma similar, indica la posibilidad de la existencia de un patrón funerario en el valle de Río Grande. ENGLISH: El Caño, located in the Coclé province, Panama, is known for its unique stone sculptural style and stone structures. Recently four lavish burials have been discovered. Dated between 700 and 1000 AD, they are broadly coeval with similar mortuary features at nearby Sitio Conte, a cemetery which provided the first archaeological evidence for the sumptuous wealth of Panamanian chiefdoms more than eighty years ago. The existence in Sitio Conte and El Caño of similar elements—alignments of basalt columns, causeways and rich tombs—with a similar spatial organization, indicates the possibility of the existence of a mortuary pattern in Río Grande.

  3. The microbial ecology of the Great Salt Lake.

    Science.gov (United States)

    Post, F J

    1977-06-01

    The Great Salt Lake is actually two lakes. A highly saline (330-gml(-1)) northern arm and a moderately saline (120-gml(-1)) southern arm separated by a semipermeable rock causeway. The lake, particularly the northern arm, has a massive accumulation of organic matter resulting from more than 100,000 years of productivity, cycling from a freshwater to a saline lake, plus the influence of human industry and agriculture in more recent times. The north arm planktonic and attached community consists principally of, in order of biomass: bacteria of at least two genera,Halobacterium andHalococcus; two algae,Dunaliella salina andD. viridis; the brine shrimp,Anemia salina; and, two species of brine fly,Ephydra gracilis andE. hians and possibly one more species. The algae and the bacteria appear to depend on each other for nutrients. The bacteria use organic matter produced by the algae and the algae use ammonia produced by the bacteria and possibly the brine shrimp. The production of ammonia appears to be the rate-limiting step although there is no shortage of other forms of nitrogen in the north arm. Based on aquarium studies, the potential for biomass production of algae and bacteria is much higher than actually observed in the north arm, leading to the postulation of two additional factors controlling population; the grazing of the algae by invertebrates with the excretion of compounds rich in nitrogen, and the effect of a low habitat temperature and winter cold on the bacteria, reducing their metabolic activities to nearly zero. Some aspects of the various organisms and their metabolism are discussed. A comparison is made with recent work on the Dead Sea. PMID:24233467

  4. Application of Sediment Trend Analysis in the Examination of Sediment Transport Dynamics of Missisquoi Bay

    Science.gov (United States)

    Kraft, M. P.; Manley, P.; Singer, J.; Manley, T.; McLaren, P.

    2013-12-01

    Missisquoi Bay is located between Vermont and Quebec in the northeast sector of the Restricted Arm of Lake Champlain. The average depth of the Bay is slightly less than 3 meters with a surface area covering 77.5 km2. The Bay receives water from eastern and western catchment basins, most notably via the Missisquoi, Rock, and Pike Rivers. Circulation within Missisquoi Bay has been altered by the construction of railroad causeways in the late 19th century and highway construction in the early 20th century. Over the past several decades there have also been changes in land-use practices, including the intensification of agriculture, increased animal husbandry, and urbanization. As a consequence of construction and changing land use, loadings of nitrogen and phosphorus to the Bay have increased seasonal oxygen depletion causing eutrophication. Since monitoring began in 1992, Missisquoi Bay has displayed the highest mean total phosphorus concentrations and chlorophyll a concentrations in Lake Champlain. Various efforts have taken place to reduce nutrient loading to Missisquoi Bay, but persistent release of phosphorus from bottom sediments will continue to delay for decades the recovery from nutrient diversion. To better understand the causes and timing of eutrophication in Missisquoi Bay, one component of a 5-year integrated VT EPSCoR - RACC program included an examination of N and P loadings and their distribution throughout the Bay. Internal circulation patterns are also being studied. To determine the pattern of net sediment transport and determine sediment behavior (erosion and accretion), a Sediment Trend Analysis (STA) was performed using 369 grab samples collected in the Bay. Grain size distributions for the surface sediment samples were determined using a Malvern Mastersizer 2000 particle size analyzer. Sediment maps showing the proportion of gravel, sand, and mud show that near major river distributaries sand-sized sediment was dominant with muds becoming more

  5. Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

    Directory of Open Access Journals (Sweden)

    Silwamba C

    2015-08-01

    Full Text Available Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the start Nchanga mining license surface already had NUG and many watershed divides with the Nchanga and Chingola streams being the main streams feeding into Zambias second largest river Kafue river and 42 of the year was characterised by heavy rains ranging between 800mm to 1300mm per annum. In this paper the presence of very significant amounts of seasonal rain and subsurface water in the mining area was identified as both a curse and a blessing. An excess in seasonal rain and subsurface water would disrupt both open pit and underground mining operations. In order for NOP to be operated successfully stable and free from flooding coping water management tactics were adopted from 1955 to 2015 including 1. Underground mine pump chamber pumping system 2. Piezometer instrumented boreholes 3. Underground mine 1500-ft sub-haulage east borehole dewatering beneath the open pit 4. Nchanga and Chingola stream diversionary tunnel and open drains 5. Nchanga stream causeway and embankment dam in the Matero School Golf Club area 6. Pit perimeter borehole pumping 7. Outer and inner pit perimeter drains and bund walls 8. In-pit ramp side drains 9. In-pit sub-horizontal borehole geo-drains and water and 10. Pit bottom sump pumps. Application of grout curtains along the Vistula River Poland was noted as a possibility in the right circumstances although it had never been used at Nchanga Open Pit. An additional conclusion was that forward health safety and environmental end

  6. Estimation of Selenium Loads Entering the South Arm of Great Salt Lake, Utah, from May 2006 through March 2008

    Science.gov (United States)

    Naftz, David L.; Johnson, William P.; Freeman, Michael L.; Beisner, Kimberly; Diaz, Ximena; Cross, VeeAnn A.

    2009-01-01

    Discharge and water-quality data collected from six streamflow-gaging stations were used in combination with the LOADEST software to provide an estimate of total (dissolved + particulate) selenium (Se) load to the south arm of Great Salt Lake (GSL) from May 2006 through March 2008. Total estimated Se load to GSL during this time period was 2,370 kilograms (kg). The 12-month estimated Se load to GSL for May 1, 2006, to April 30, 2007, was 1,560 kg. During the 23-month monitoring period, inflows from the Kennecott Utah Copper Corporation (KUCC) Drain and Bear River outflow contributed equally to the largest proportion of total Se load to GSL, accounting for 49 percent of the total Se load. Five instantaneous discharge measurements at three sites along the railroad causeway indicate a consistent net loss of Se mass from the south arm to the north arm of GSL (mean = 2.4 kg/day, n = 5). Application of the average daily loss rate equates to annual Se loss rate to the north arm of 880 kg (56 percent of the annual Se input to the south arm). The majority of Se in water entering GSL is in the dissolved (less than 0.45 micron) state and ranges in concentration from 0.06 to 35.7 micrograms per liter (ug/L). Particulate Se concentration ranged from less than 0.05 to 2.5 ug/L. Except for the KUCC Drain streamflow-gaging station, dissolved (less than 0.45 um) inflow samples contain an average of 21 percent selenite (SeO32-) during two sampling events (May 2006 and 2007). Selenium concentration in water samples collected from four monitoring sites within GSL during May 2006 through August 2007 were used to understand how the cumulative Se load was being processed by various biogeochemical processes within the lake. On the basis of the Mann-Kendall test results, changes in dissolved Se concentration at the four monitoring sites indicate a statistically significant (90-percent confidence interval) upward trend in Se concentration over the 16-month monitoring period. Furthermore

  7. Interaction between shallow groundwater, saline surface water and nutrient discharge in a seasonal estuary: the Swan-Canning system

    Science.gov (United States)

    Linderfelt, William R.; Turner, Jeffrey V.

    2001-09-01

    The Swan and Canning Rivers converge to form an estuary that is seasonally forced by wet winter and dry summer conditions. The estuary is also tidally forced due to its contact with the Indian Ocean. The perception that the occurrence of nuisance algal blooms has increased in frequency and severity in recent years has prompted the present investigation into the interaction of the shallow groundwater system with the Swan-Canning Estuary. The extent to which this interaction contributes to nutrient delivery to the river is a focus of the work.Groundwater interaction with the upper reaches of the Swan River is shown to occur at three length scales: (i) the scale of the river-bed sediments (i.e. 1000 m). Two-dimensional groundwater flow modelling in plan covering the regionally advected groundwater flow domain of the upper Swan River Estuary from the Causeway to Guildford shows that there is a net groundwater discharge to the Swan River of groundwater discharge of about 80 000 m3/day, or about 29 million m3/year. Between 1987 and 1996, the average surface tributary inflow to the Swan River was about 460 million m3/year. Thus groundwater discharge contributed approximately 6% of the total annual river flow. This percentage is clearly small in comparison to the total river flow. However, in the six months from November to April in summer, tributary flow into the Swan River declines sharply to an average total of approximately 12 million m3. Groundwater discharge during this six-month period is approximately 14 million m3 or about 55% of the surface tributary flow, and thus groundwater is a significant component of the total inflow to the Swan-Canning Estuary during this period. Nutrient concentrations, particularly ammonium, within the sediment pore fluids underlying the river are very high relative to concentrations in the river, such that groundwater discharge rates of this magnitude are capable of introducing significant nutrient loadings to the river. The nitrogen

  8. Anthropogenic influences on the input and biogeochemical cycling of nutrients and mercury in Great Salt Lake, Utah, USA

    Energy Technology Data Exchange (ETDEWEB)

    Naftz, David [US Geological Survey, Salt Lake City 84119, UT (United States)], E-mail: dlnaftz@usgs.gov; Angeroth, Cory; Kenney, Terry [US Geological Survey, Salt Lake City 84119, UT (United States); Waddell, Bruce; Darnall, Nathan [US Fish and Wildlife Service, Salt Lake City, UT (United States); Silva, Steven [US Geological Survey, Menlo Park, CA (United States); Perschon, Clay [Utah Division of Wildlife Resources, Salt Lake City, UT (United States); Whitehead, John [Utah Department of Environmental Quality, Salt Lake City, UT (United States)

    2008-06-15

    Despite the ecological and economic importance of Great Salt Lake (GSL), little is known about the input and biogeochemical cycling of nutrients and trace elements in the lake. In response to increasing public concern regarding anthropogenic inputs to the GSL ecosystem, the US Geological Survey (USGS) and US Fish and Wildlife Service (USFWS) initiated coordinated studies to quantify and evaluate the significance of nutrient and Hg inputs into GSL. A 6 per mille decrease in {delta}{sup 15}N observed in brine shrimp (Artemia franciscana) samples collected from GSL during summer time periods is likely due to the consumption of cyanobacteria produced in freshwater bays entering the lake. Supporting data collected from the outflow of Farmington Bay indicates decreasing trends in {delta}{sup 15}N in particulate organic matter (POM) during the mid-summer time period, reflective of increasing proportions of cyanobacteria in algae exported to GSL on a seasonal basis. The C:N molar ratio of POM in outflow from Farmington Bay decreases during the summer period, supportive of the increased activity of N fixation indicated by decreasing {delta}{sup 15}N in brine shrimp and POM. Although N fixation is only taking place in the relatively freshwater inflows to GSL, data indicate that influx of fresh water influences large areas of the lake. Separation of GSL into two distinct hydrologic and geochemical systems from the construction of a railroad causeway in the late 1950s has created a persistent and widespread anoxic layer in the southern part of GSL. This anoxic layer, referred to as the deep brine layer (DBL), has high rates of SO{sub 4}{sup 2-} reduction, likely increasing the Hg methylation capacity. High concentrations of methyl mercury (CH{sub 3}Hg) (median concentration = 24 ng/L) were observed in the DBL with a significant proportion (31-60%) of total Hg in the CH{sub 3}Hg form. Hydroacoustic and sediment-trap evidence indicate that turbulence introduced by internal waves

  9. Effects of the 26 December 2004 Indian Ocean Tsunami in the Republic of Seychelles

    Science.gov (United States)

    Jackson, L. E.; Barrie, J. V.; Forbes, D. L.; Shaw, J.; Manson, G. K.; Schmidt, M.

    2005-12-01

    , whereas the highest water level in the city of Victoria (on the northeast side of Mahé) occurred about 16 hours after the first arrival (but with much lower wave energy). Damage to public works was greatest in the Victoria area. Lateral spread failures developed in artificial fills forming the fishing port. Liquefaction was induced in these fills by cyclic inundation, saturation and rapid draw-down. Washouts occurred on two sections of highway causeway crossing reclaimed land south of Victoria due to the rapid drainage of tsunami floodwaters. Similar erosion caused structural failure of hotel buildings on Praslin. Elsewhere, the greatest damage was coincident with preexisting modification of the coast by development including: removal of natural beach berms, construction of hotel structures adjacent to the high-water mark or seaward over the beach, and placement of roads immediately adjacent to beaches. The damaging effects of the tsunami were confined to the granitic islands of Seychelles archipelago. The lack of impact on the atolls is due to the deep water surrounding them: this resulted in minimal shoaling and amplification of the long wavelength and low-amplitude tsunami waves.

  10. Anthropogenic influences on the input and biogeochemical cycling of nutrients and mercury in Great Salt Lake, Utah, USA

    Science.gov (United States)

    Naftz, D.; Angeroth, C.; Kenney, T.; Waddell, B.; Darnall, N.; Silva, S.; Perschon, C.; Whitehead, J.

    2008-01-01

    Despite the ecological and economic importance of Great Salt Lake (GSL), little is known about the input and biogeochemical cycling of nutrients and trace elements in the lake. In response to increasing public concern regarding anthropogenic inputs to the GSL ecosystem, the US Geological Survey (USGS) and US Fish and Wildlife Service (USFWS) initiated coordinated studies to quantify and evaluate the significance of nutrient and Hg inputs into GSL. A 6??? decrease in ??15N observed in brine shrimp (Artemia franciscana) samples collected from GSL during summer time periods is likely due to the consumption of cyanobacteria produced in freshwater bays entering the lake. Supporting data collected from the outflow of Farmington Bay indicates decreasing trends in ??15N in particulate organic matter (POM) during the mid-summer time period, reflective of increasing proportions of cyanobacteria in algae exported to GSL on a seasonal basis. The C:N molar ratio of POM in outflow from Farmington Bay decreases during the summer period, supportive of the increased activity of N fixation indicated by decreasing ??15N in brine shrimp and POM. Although N fixation is only taking place in the relatively freshwater inflows to GSL, data indicate that influx of fresh water influences large areas of the lake. Separation of GSL into two distinct hydrologic and geochemical systems from the construction of a railroad causeway in the late 1950s has created a persistent and widespread anoxic layer in the southern part of GSL. This anoxic layer, referred to as the deep brine layer (DBL), has high rates of SO42 - reduction, likely increasing the Hg methylation capacity. High concentrations of methyl mercury (CH3Hg) (median concentration = 24 ng/L) were observed in the DBL with a significant proportion (31-60%) of total Hg in the CH3Hg form. Hydroacoustic and sediment-trap evidence indicate that turbulence introduced by internal waves generated during sustained wind events can temporarily mix the

  11. PREFACE: Kelvin and Ireland

    Science.gov (United States)

    Flood, Raymond; McCartney, Mark; Whitaker, Andrew

    2009-07-01

    frequent visitor. While the most celebrated example of his engineering work was his massive contribution to the Atlantic telegraph cable, and his maritime and other inventions were used throughout the world, he was especially pleased to contribute to two important technical accomplishments in the north of Ireland, the occulting Holywood lighthouse and the Giant's Causeway tramway. Kelvin's interest in Ireland came again to the fore in the Home Rule debate at the end of the nineteenth century; Kelvin was vehemently opposed to Home Rule and became a passionate member of the Liberal Unionist party, a crucial factor in his becoming a peer. Accounts of these aspects of Kelvin's involvement with Ireland are given in our first four papers. The fifth paper was particularly appropriate for the meeting. It describes how an important contribution of Kelvin on optimal packing has been improved in Ireland by the speaker, Denis Weaire, himself, and how the result has been seen by the whole world in Beijing. Finally there is a discussion of Kelvin's place in the story of Irish science. There have been many highly accomplished Irish scientists, and the meeting showed clearly that Kelvin certainly deserves to be included among the greatest. Acknowledgments The meeting was the second regional event of the Institute of Physics (IOP) in Ireland, the first being the meeting on John Desmond Bernal: Science and Society held in Limerick in June 2006 and published in the same series as this volume. The meeting also benefited from the support of many bodies and institutions. We would like to thank the committee of the IOP in Ireland for providing finance and also giving their full support. We would particularly mention Vincent Casey, the Chair, who also chaired the afternoon session, Emma Sokell, the Secretary, and Denise Gabuzda and Kevin McGuigan, past and present Treasurers. We would also thank Sheila Gilheany and Alison Hackett for general help and encouragement, including assisting the

  12. The Costa Maya:  Evolution of a Touristic Landscape La Costa Maya : évolution d'un paysage touristique La Costa Maya : evolución de un paisaje turístico

    Directory of Open Access Journals (Sweden)

    Klaus J. Meyer-Arendt

    2010-06-01

    ecotourism.  Development so far has been concentrated in Puerto Costa Maya, where a cruise ship pier and terminal were built in 2001.  The nearby beach resort (balneario of Majahual became dependent upon the 10-12 shiploads of tourists that descended upon it every week.  In spite of big development plans, the more remote beaches of the Costa Maya cater to fewer, but well-heeled ecotourists and dive tourists.  Hurricane Dean made landfall in August 2007 as a category-5 storm, and economic recovery only began in late 2008 when the cruise ship pier re-opened and Majahual rebuilt.  As of late 2009, the cruise-ship traffic had still not recovered to pre-Dean levels, and a global recession coupled with swine-flu and drug violence scares has lowered U.S. tourism to Mexico.  To what degree new tourism infrastructure such as an international airport at Tulum, a proposed causeway from Chetumal to the beach, and a new resort complex at Xahuayxel will stimulate tourism on the Mexican Costa Maya and eventually lead to a coastal highway link with San Pedro, Belize is still unknown.

  13. Editorial: Is This Any Way to Develop Policy?

    Directory of Open Access Journals (Sweden)

    Michael H. Miner

    2007-06-01

    investigation. Nor were they enacted after considering what the empirical research available in the mid to late 1990’s told us about sexual crimes and the effectiveness of sexual offender treatment. They were enacted to respond to public outcry following terrible, but anomalous, incidents. In fact, while each new law was justified by the high risk posed by repeat sex offenders, the empirical data indicated that at the time these laws were enacted, the rates of child sexual abuse were declining in the United States (Finkelhor & Jones, 2006 and the risk posed by convicted, identified sexual offenders was, and currently remains, actually quite low – ranging from a high of 24% (Harris & Hanson, 2004 to 5.3% (Bureau of Justice Statistics, 2003.The above process continues, unabated, here in the United States. We keep coming up with new ideas, such as residence restrictions, which have resulted in parolees in Florida living under a causeway and registered sexual offenders in Iowa living at interstate rest stops. Such residences would appear to increase public risk, rather than protect the public. Sex offender treatment, in such circumstances, would certainly appear to be a waste of time and resources, in that individuals concerned about where they can live and whether they can get a job, are in no place to work on the types of issues addressed by most treatment interventions. However, with each new heinous incident, our law makers do not appear to consider the possibility that the already enacted legislation is at best useless and at worst iatrogenic, they simply assume that the laws are not strict enough and must be “strengthened.” Thus, we in the U.S.A find ourselves in an environment where sexual offenders are society’s worst villains (although that might change now that our Federal government seems more focused on terrorists, they are all the same, and they will always be dangerous. Any suggestion that this is not the case, even though all of the available data indicate