WorldWideScience

Sample records for north sea oil

  1. North Sea oil directory 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    This edition of the North Sea Oil Directory has been revised to keep pace with the ever-changing North Sea industry. The information is grouped under the following topics: exploration and production; group licensees; Dutch and Norwegian licensees; UK Offshore Operators Association Committees; drilling contractors; offshore exploration and surveys; cement, drilling fluids, and related equipment; drilling equipment; prime mover, transmission equipment; production and process equipment; rig and platform equipment suppliers; rig builders, ship builders; rig and platform logistics; ports, supply bases; marine civil engineering; specialized equipment and services; classified index; and an alphabetical index. (MCW)

  2. North Sea oil and the environment

    International Nuclear Information System (INIS)

    Cairns, W.J.

    1992-01-01

    This book, which is arranged in five sections, provides an historical record of the development of North Sea oil and gas over the past twenty years and records the lessons learnt from this experience. This first section provides an introductory framework to the three main themes, namely resources, environment and development. Section 2 is primarily concerned with the economic and social consequences of oil related development at two levels; firstly on the national economy and secondly the impact on local communities. Section 3 deals with impacts upon the physical environment and introduces the statutory land use planning system in Scotland. The Scottish approach to environmental assessment is reviewed and the need for mitigation by design explored. Section 4 examines specific field developments, and reviews the statutory controls and international initiatives regulating the extent of environmental disturbance and pollution from offshore operations. The effects of oil spillage and submarine pipelines on the environment and their impact on the fishing industry is followed by a discussion on the decommissioning and abandonment of offshore installations. Section 5 deals with the role and value of hazard and risk analysis in the siting, layout and safety zoning of onshore facilities and develops a case study on a major fractionation facility. The means of mitigating acute and chronic environmental risks are considered. A postscript provides a range of past comments and criticisms and finally draws some conclusions on the performance of environmental management and North Sea oil development. The North Sea oil and gas development experience proves that with wisdom, forethought and goodwill, industrial exploiters of natural resources can operate economically within legislative, policy, scientific, technical and design parameters without causing long-term irreversible environmental damage. (author)

  3. North Sea oil taxation in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, A G; Crichton, D

    1979-01-01

    The Norwegian government has developed a complex fiscal regime since 1963 to cover the activities of oil companies in the North Sea. The purpose of this article is to identify and quantify the financial effects of the fiscal system on operating companies involved in the Norwegian sector. The emphasis is on the effect of the tax package introduced by the government in the Odelsting Proposition No. 26 of February 1975. The impact of the tax is not found to be well related to the profitability of fields and the sensitivity of the tax burden to key variables such as reserves, oil price, capital and operating costs and inflation is examined. The most promising change appears to be a discriminatory refund or remission of royalty payments to marginal fields. The Act's main innovation, Special Tax, fails to discriminate between fields of profitability and could influence development decisions in marginal fields. The special allowance provision, by reducing the real cost of capital expenditure and favoring capital-intensive operations, could influence the techniques of exploitation. The effect of quasi-fiscal measures, particularly of government participation via Statoil, is also examined. 10 references.

  4. Lifestyle survey amongst North Sea oil workers

    Energy Technology Data Exchange (ETDEWEB)

    Horsley, Harry [RGIT Ltd., Research Unit, Aberdeen (United Kingdom); MacKenzie, I.G. [Robert Gordon Univ., School of Computer and Mathematical Sciences, Aberdeen (United Kingdom)

    1997-12-31

    Recognition is growing of the influence of the workplace on lifestyle, and its consequent effect on health. This relation between work, lifestyle and health is highly relevant to the North Sea oil and gas industry where employment often demands the adoption of, and exposure to, a lifestyle far removed from that of comparable onshore occupations. This risk factors for Coronary Heart Disease (CHD) which is the largest single cause of premature adult death in Great Britain can be classified according to those that are immodifiable (eg gender), and those that result from lifestyle choices (eg smoking, diet). The demographic profile (predominant gender, age group and nationality) of the offshore workforce is thought to place it in an inherently high risk group for CHD. Anecdotal evidence further suggests that the offshore lifestyle may expose the workforce to increased CHD risk factors, particularly in terms of diet, tobacco consumption and exercise habits. The lifestyle of offshore workers may be considered as a form of occupational hazard, comparable with recognised occupational risks. A sample of 500 offshore workers undertaking survival training were surveyed using a structured questionnaire to investigate aspects of their lifestyle. Subjects compared their smoking, dietary and exercise habits between periods onshore and offshore. Analysis of results pointed to some significant differences in lifestyle between these two periods. Additional factors such as occupation status (whether directly employed or contracted), onshore alcohol consumption, and subjects` perception of job and family satisfaction were also analysed in relation to lifestyle. Results indicate the potential benefits of health promotion intervention. Opportunities for such intervention are identified and discussed within the context of caring for an efficient utilisation of the Offshore Industry`s human resources. (Author)

  5. North Sea oil and gas: a geographical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, K

    1976-01-01

    Only ten years after the first rig moved into position, British oil has been piped ashore from the North Sea and, by 1980, will be making a substantial contribution to UK energy supplies. The discovery of natural gas in 1967--for initially gas was the primary objective--has transformed the gas supply so that 90% of the UK's needs already come from the North Sea. The speed and concentration of exploration pinpoints the vital importance of this new energy source. Until now the major oil 'pipeline' in the world has been led between the Middle East and Western Europe, so this new energy source has far reaching implications, both political and economic. Keith Chapman examines these implications starting from events in the North Sea itself; the geological background, agreement on the division of the North Sea, relations between oil companies, and government embodied in offshore mining legislation. The latter part of the book concentrates on the onshore repercussions of offshore activities; how North Sea oil fits into the international oil system, the various options open for its utilisation, the attitude of the EEC towards Scottish-based resources, government policy for the North coast of Scotland--an area which planners classed as ''peripheral'' but which must now accommodate extensive support facilities and service industries for the oil sites. There is also the question of relations between national and commercial interests--government versus the giant multi-national companies which took the initial gamble in the North Sea and are now responsible for the development of a resource vital to the economic well-being of Western Europe.

  6. The importance of North Sea oil to European energy supply

    International Nuclear Information System (INIS)

    Bauw, R. De

    1992-01-01

    There is no doubt about the importance of North Sea oil to the energy supply of the European Community. One might however be used to it and forget about the nature and the size of its impact on our economies. Firstly, this paper intends to estimate this impact - past, present and future. Secondly, a more qualitative approach will explore possible consequences of the implementation of the internal market for North Sea oil. Thirdly, the assistance given by the Community to innovative technologies which enabled North Sea oil to contribute, under better economic conditions and within a safer environment, to our supply is recalled. And finally, some remarks on energy policy form an EC perspective, are offered. (author)

  7. Emissions from oil platforms in the North Sea

    International Nuclear Information System (INIS)

    Kanowski, S.

    1991-01-01

    When oil and gas are extracted from below the sea bed, emissions generally occur drilling and extraction and when offshore installations are abandoned. The sources of such emissions are the drilling fluids which contain many chemicals, cuttings, extracted hydrocarbons, substances released as a result of accidents, and the improper disposal of substances used in drilling and production. Platforms are regarded as land-based installations. Regulations to limit emissions have been put into effect within the scope of the Paris Convention on the protection of the North Sea and the North-East Atlantic. (orig.) [de

  8. UK wants more revenue from North Sea oil

    Energy Technology Data Exchange (ETDEWEB)

    1973-03-09

    The first report from the Committee of Public Accounts of the UK Parliament on North Sea gas and oil has revealed a situation under which the UK Exchequer apparently does not receive cash intake comparable to the Exchequers of other oil producing countries. So important are these findings that some of them are presented so that the industry at large, and particularly those engaged in North Sea exploration and production, will be aware of the UK situation. Recomendations are made that the government should take action substantially to improve the effective tax yield from operations on the continental shelf, and should consider among other methods the possibility of imposing a system of quantity taxation.

  9. Phase equilibrium of North Sea oils with polar chemicals: Experiments and CPA modeling

    DEFF Research Database (Denmark)

    Frost, Michael Grynnerup; Kontogeorgis, Georgios M.; von Solms, Nicolas

    2016-01-01

    This work consists of a combined experimental and modeling study for oil - MEG - water systems, of relevance to petroleum applications. We present new experimental liquid-liquid equilibrium data for the mutual solubility of two North Sea oils + MEG and North Sea oils + MEG + water systems...

  10. Emerald oil field on production in North Sea

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that Midland and Scottish Energy Ltd. (MSE) has placed Emerald oil field on stream in the U.K. North Sea with a floating production unit. Initial production, from two satellite wells, will be used to commission facilities. Three water injection wells have been unplugged and are ready for start-up. MSE will place a central cluster of wells-five producers and one water injector-on stream during the next few weeks. Production will build to an expected 25,000 b/d from 35 million bbl of reserves. Field development has undergone an unusually large number of setbacks and changes

  11. Britain's North Sea oil and gas production: a critical review

    International Nuclear Information System (INIS)

    Odell, P.R.

    1996-01-01

    The size and longevity of Britain's offshore hydrocarbons resources have been underestimated. Gas reserves were seriously under-exploited for almost 20 years from the late 1960s, given a belief that gas should be used only as a premium fuel and in the context of an uncompetitive market. Oil reserves' development and production has suffered from time to time from inappropriate politico-economic conditions. Nevertheless, offshore oil and gas has come to dominate the UK's energy production over the past 20 years and currently accounts for 85% of the country's total energy output. Fears for resources' exhaustion remain unjustified, as the industry continues to replace oil and gas reserves used each year. The North Sea is still not comprehensively explored: the continuation of the process will enable oil production to remain at high levels and that of gas to expand further. Supplementary output from the new west of Shetland province will become progressively more important after 2000. But continued intensive production overall depends on the maintenance of attractive politico-economic conditions and on present oil prices. It also requires the European gas market to remain firm but, ironically, the planned flow of UK gas to the mainland constitutes a threat to this condition. (Author)

  12. The North Sea oil and gas industry and the environment

    International Nuclear Information System (INIS)

    Kingston, P.F.

    1992-01-01

    The North Sea environment is described. Inputs into this environment from oil and gas installations are relatively modest compared with the pollution from effluent discharged or directly dumped into the sea by its highly populated and industrialized enclosing nations. Hydrocarbon discharges provide the greatest input from the oil and gas industry and make a substantial contribution to the total hydrocarbon input. The sources from offshore installations are analysed. Accidental spills, flaring, atmospheric emissions and other inputs are discussed. Biological and chemical monitoring over many year has shown that the most common environmental effect is a marked fall in the number of species of marine fauna and an increase in the number of individuals. These effects appear within 1000 metres of the installation. The spread of contaminants may be more widespread than the biological response indicates, though. The cost of environmental protection is briefly considered. A need to determined the wider impact of low levels of contamination detected at greater distances from platform activities and the development of effective environmental management plans are identified as two objectives for the future. (UK)

  13. Effects of changes in UK North Sea oil taxation

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, A G; Crichton, D

    1979-10-01

    Changes in North Sea oil tax structure were introduced by the United Kingdom government in mid-1979. The new system is aimed at increasing revenues to the state without damage to exploitation and production. The effects that the new tax regime and each of its components will have on different types of fields being exploited under various circumstances are examined. The analysis also considers sensitivity to capital-cost inflation, effects on multi-field operation, and the results of two other possible tax schemes. It is found that the new tax scheme will considerably alter the structure of the tax burden and will increase the overall tax take. Marginal tax rates will also increase, not least for some fields with low expected returns. The new scheme will, however, continue to favor capital-intensive exploitation techniques. 2 references, 17 tables.

  14. Investigation of a North Sea oil platform drill cuttings pile

    International Nuclear Information System (INIS)

    Hartley, J.P.; Watson, T.N.

    1993-01-01

    A comprehensive study of the drill cuttings pile at North West Hutton was undertaken in August, 1992. Fifty one wells have been drilled in the field, mainly using mineral oil based drill fluids, with the cuttings discharged to sea. The cuttings pile was mapped using a 3D side scan sonar system and the periphery was defined by towed side scan sonar and gamma ray spectrometer surveys. The pile was cored by vibrocorer to a maximum depth of 2.35m. The cores were assessed geotechnically and subsampled for physical and chemical analyses. Environmental impact was investigated by grab sampling at 12 stations out to 7,500m, selected on the basis of cuttings distribution. The results are relevant to the corrosion and long-term environmental effects of oily cuttings piles, the remove/leave alone debate, and abandonment planning. The cores were subsampled for hydrocarbon, trace metals and sulphide content and grain size analysis. Metals analyses included identification of metal species to estimate bioavailability and implications of pile disturbance. Estimates of oil migration within the pile are made from correlation of the chemical analyses results with the drilling history, in particular the change from diesel to low toxicity base oil in 1984. Strong gradients were found in the faunal data which correlate well with the physical and chemical results. Dense populations of opportunists species were present adjacent to the platform, including a novel molluscan opportunist. This is the first comprehensive study of an oily cuttings pile and is a contribution to the debate on their long term impact and fate on abandonment

  15. Exploration and development of offshore oil and gas fields. [North Sea

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    In the last 9 years, the British companies, based on their rich engineering and commercial experience, have directed a considerable part of their material and manpower resources at developing oil and gas fields in the North Sea. The technological innovations used by British industry are: aero- and marine surveys to prospect for oil, underwater laying of pipelines, arrangement of platforms, etc.; exploratory drilling in the open sea and on dry land; design of platforms with regard for the depth of the water and unique weather conditions of the North Sea, their assembly and development; use of auxiliary ships and helicopters, and diving equipment.

  16. Density and viscosity behavior of a North Sea crude oil, natural gas liquid, and their mixtures

    DEFF Research Database (Denmark)

    Schmidt, KAG; Cisneros, Sergio; Kvamme, B

    2005-01-01

    to accurately model the saturation pressures, densities, and viscosities of petroleum systems ranging from natural gases to heavy crude oils. The applicability of this overall modeling technique to reproduce measured bubble points, densities, and viscosities of a North Sea crude oil, a natural gas liquid...

  17. The continuing investment attraction af the North Sea to a large oil company

    International Nuclear Information System (INIS)

    Bijur, P.

    1992-01-01

    The North Sea is a success story of a partnership between government and industry in which everyone is winning. This paper considers what it will take to keep the success story going - to keep the North Sea attractive to large investors. First, the most significant of the future challenges facing investors here are outlined -competing investments, declining prospectivity and technical barriers. Some positive recommendations follow that may enable the oil industry to overcome the challenges and keep the North Sea a centre for petroleum investment into the next century. (author)

  18. Modelling and analysis of offshore energy systems on North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Elmegaard, Brian; Pierobon, Leonardo

    2012-01-01

    export, and power generation. In this paper, a generic model of a North Sea oil and gas platform is described and the most thermodynamically inefficient processes are identified by performing an exergy analysis. Models and simulations are built and run with the tools Aspen Plus R, DNA and Aspen HYSYS R...

  19. North Sea oil, the UK economy and macroeconomic adjustment -an overview, theoretical and simulation analysis

    International Nuclear Information System (INIS)

    Harvie, Charles

    1992-01-01

    The discovery and production of oil from the UK sector of the North Sea has had, and will continue to have for some time yet, an important impact upon developments in that economy. This paper is concerned with identifying the major characteristics of this oil production, and the macroeconomic developments which have arisen in the UK during its period of production. A theoretical framework, incorporating these characteristics, is developed, to identify the contribution of oil production and price changes to these as well as future developments. (author)

  20. Water scaling in the North Sea oil and gas fields and scale prediction: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, M

    1997-12-31

    Water-scaling is a common and major production chemistry problem in the North Sea oil and gas fields and scale prediction has been an important means to assess the potential and extent of scale deposition. This paper presents an overview of sulphate and carbonate scaling problems in the North Sea and a review of several widely used and commercially available scale prediction software. In the paper, the water chemistries and scale types and severities are discussed relative of the geographical distribution of the fields in the North Sea. The theories behind scale prediction are then briefly described. Five scale or geochemical models are presented and various definitions of saturation index are compared and correlated. Views are the expressed on how to predict scale precipitation under some extreme conditions such as that encountered in HPHT reservoirs. 15 refs., 7 figs., 9 tabs.

  1. Wettability Improvement with Enzymes: Application to Enhanced Oil Recovery under Conditions of the North Sea Reservoirs

    DEFF Research Database (Denmark)

    Khusainova, Alsu; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    (Nasiri et al., 2009), working mechanisms are poorly known and understood. The main goal of the present work is to establish possible mechanisms in which enzymes may enhance oil recovery. Improvement of the brine wettability of the rock and decrease of oil adhesion to it by addition of an enzyme is one...... of the possible mechanisms of enzymatic action. This mechanism has been investigated experimentally, by measurements of the contact angles between oil drops and enzyme solutions in brine on the mineral surfaces. Fifteen enzyme samples belonging to different enzyme classes, such as esterases/lipases, carbohydrases......, proteases and oxidoreductases, provided by Novozymes, have been investigated. Two commercial mixtures containing enzymes: Apollo-GreenZyme™ and EOR-ZYMAX™ have also been applied. The North Sea dead oil and the synthetic sea water were used as test fluids. Internal surface of a carbonate rock has been...

  2. Sulfate-Reducing Prokaryotes from North Sea Oil reservoirs; organisms, distribution and origin

    Energy Technology Data Exchange (ETDEWEB)

    Beeder, Janiche

    1996-12-31

    During oil production in the North Sea, anaerobic seawater is pumped in which stimulates the growth of sulphate-reducing prokaryotes that produce hydrogen sulphide. This sulphide causes major health hazards, economical and operational problems. As told in this thesis, several strains of sulphate reducers have been isolated from North Sea oil field waters. Antibodies have been produced against these strains and used to investigate the distribution of sulphate reducers in a North Sea oil reservoir. The result showed a high diversity among sulphate reducers, with different strains belonging to different parts of the reservoir. Some of these strains have been further characterized. The physiological and phylogenetic characterization showed that strain 7324 was an archaean. Strain A8444 was a bacterium, representing a new species of a new genus. A benzoate degrading sulphate reducing bacterium was isolated from injection water, and later the same strain was detected in produced water. This is the first field observations indicating that sulphate reducers are able to penetrate an oil reservoir. It was found that the oil reservoir contains a diverse population of thermophilic sulphate reducers able to grow on carbon sources in the oil reservoir, and to live and grow in this extreme environment of high temperature and pressure. The mesophilic sulphate reducers are established in the injection water system and in the reservoir near the injection well during oil production. The thermophilic sulphate reducers are able to grow in the reservoir prior to, as well as during production. It appears that the oil reservoir is a natural habitat for thermophilic sulphate reducers and that they have been present in the reservoir long before production started. 322 refs., 9 figs., 11 tabs.

  3. Sulfate-Reducing Prokaryotes from North Sea Oil reservoirs; organisms, distribution and origin

    Energy Technology Data Exchange (ETDEWEB)

    Beeder, Janiche

    1997-12-31

    During oil production in the North Sea, anaerobic seawater is pumped in which stimulates the growth of sulphate-reducing prokaryotes that produce hydrogen sulphide. This sulphide causes major health hazards, economical and operational problems. As told in this thesis, several strains of sulphate reducers have been isolated from North Sea oil field waters. Antibodies have been produced against these strains and used to investigate the distribution of sulphate reducers in a North Sea oil reservoir. The result showed a high diversity among sulphate reducers, with different strains belonging to different parts of the reservoir. Some of these strains have been further characterized. The physiological and phylogenetic characterization showed that strain 7324 was an archaean. Strain A8444 was a bacterium, representing a new species of a new genus. A benzoate degrading sulphate reducing bacterium was isolated from injection water, and later the same strain was detected in produced water. This is the first field observations indicating that sulphate reducers are able to penetrate an oil reservoir. It was found that the oil reservoir contains a diverse population of thermophilic sulphate reducers able to grow on carbon sources in the oil reservoir, and to live and grow in this extreme environment of high temperature and pressure. The mesophilic sulphate reducers are established in the injection water system and in the reservoir near the injection well during oil production. The thermophilic sulphate reducers are able to grow in the reservoir prior to, as well as during production. It appears that the oil reservoir is a natural habitat for thermophilic sulphate reducers and that they have been present in the reservoir long before production started. 322 refs., 9 figs., 11 tabs.

  4. Comparative study of the sources of exergy destruction on four North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian

    2013-01-01

    temperatures and pressures, gas- and water-to-oil ratios in the feed, crude oil properties, product specifications and recovery strategies. These differences imply that some platforms naturally need less power for oil and gas processing than others. Reservoir properties and composition also vary over......In this paper, the oil and gas processing systems on four North Sea offshore platforms are reported and discussed. Sources of exergy destruction are identified and the findings for the different platforms are compared. Different platforms have different working conditions, such as reservoir...... the lifetime of an oil field, and to maintain the efficiency of an offshore platform is therefore challenging. In practice, variations in the process feed result in the use of control strategies such as anti-surge recycling, which cause additional power consumption and exergy destruction. For all four...

  5. Finance and North Sea oil: the challenge of non-recourse finance

    Energy Technology Data Exchange (ETDEWEB)

    White, N A

    1976-04-01

    Many companies operating in the North Sea feel that the financial community is not responding to the complexity of their situation brought about by the interplay between national legislation and fiscal measures, technological development, extreme weather conditions, OPEC decisions, or falling oil demand. The financial community feels it is lending its depositors' money and the kind of innovations required by some companies in the oil industry would reduce its level of security. After reviewing the possible solutions, the author concludes that it is highly unlikely that non-resource finance in large amounts will be available without collateral, or other security, from outside the North Sea area. The author offers his suggestion and preference for a new kind of vehicle to be designed by the financial institutions that would provide the necessary guarantees to the lending consortium in accordance with the needs of the individual participant in the license or field project. (MCW)

  6. CO2 enhanced oil recovery and storage in the North Sea - a UK perspective

    International Nuclear Information System (INIS)

    Beckly, Andy; Hughes, David S.

    2006-01-01

    Considerable technical and economic challenges must be overcome if the potential for CO 2 injection and sequestration is to be fully realised. However, there is an opportunity to exploit the synergy between the need to reduce CO 2 emissions and the potential to use CO 2 to increase North Sea oil reserves and extend the life of the basin. This opportunity is available now, while the infrastructure remains in place

  7. North Sea oil taxation: principles, methods and evidence

    International Nuclear Information System (INIS)

    Rutledge, I.; Wright, P.

    1998-01-01

    The analysis of fiscal systems in the World oil and gas industry has become rather narrowly abstract and technical over the past decade. Wider issues of political economy have often been ignored while attention has focused on forecasting the fiscal systems on ex ante profitability and investment decisions using increasingly sophisticated computer models. At a time when the UK government has been considering reform of the UK oil and gas fiscal system it is appropriate to remind ourselves that there is a rich literature on the subject stretching back to the nineteen sixties and beyond, and that many of the insights of these earlier writers are well worth our close consideration. At the same time some more recent contributors have injected new elements into the debate which also depart from what we would see as 'neo-classical' orthodoxy on this subject. Their work is also briefly reviewed in this paper. The related questions of methods and evidence have also, in our view, become focused in a rather narrow direction with little consideration being given to either ex post historical data or the considerable body of empirical material to be found in oil and gas companies. This paper therefore also seeks to widen our horizons about the different sorts of 'raw material' which might be drawn upon in determining the right direction for current UK fiscal policy or indeed oil and gas fiscal policy in general. (author)

  8. Improved oil recovery using bacteria isolated from North Sea petroleum reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Davey, R.A.; Lappin-Scott, H. [Univ. of Exeter (United Kingdom)

    1995-12-31

    During secondary oil recovery, water is injected into the formation to sweep out the residual oil. The injected water, however, follows the path of least resistance through the high-permeability zones, leaving oil in the low-permeability zones. Selective plugging of these their zones would divert the waterflood to the residual oil and thus increase the life of the well. Bacteria have been suggested as an alternative plugging agent to the current method of polymer injection. Starved bacteria can penetrate deeply into rock formations where they attach to the rock surfaces, and given the right nutrients can grow and produce exo-polymer, reducing the permeability of these zones. The application of microbial enhanced oil recovery has only been applied to shallow, cool, onshore fields to date. This study has focused on the ability of bacteria to enhance oil recovery offshore in the North Sea, where the environment can be considered extreme. A screen of produced water from oil reservoirs (and other extreme subterranean environments) was undertaken, and two bacteria were chosen for further work. These two isolates were able to grow and survive in the presence of saline formation waters at a range of temperatures above 50{degrees}C as facultative anaerobes. When a solution of isolates was passed through sandpacks and nutrients were added, significant reductions in permeabilities were achieved. This was confirmed in Clashach sandstone at 255 bar, when a reduction of 88% in permeability was obtained. Both isolates can survive nutrient starvation, which may improve penetration through the reservoir. Thus, the isolates show potential for field trials in the North Sea as plugging agents.

  9. Performance indicators for evaluation of North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian

    2013-01-01

    Well-defined performance indicators can motivate optimal operation of offshore oil and gas platforms. This paper aims to develop such parameters, indicating possibilities for reducing power consumption and emissions of pollutants. Different platforms have different oilfield conditions and process...... specifications. Such conditions determine the theoretical minimum work required to operate the platforms, and can have a high impact on the power consumption. We introduce performance indicators based on energy and exergy. The specific energy use and specific exergy consumption evaluate the resources spent...... required under ideal conditions (i.e. reversible operation), and specific exergy destruction illustrates the amount of resources lost due to irreversibilities. We use these indicators to evaluate the oil and gas processing at four different North Sea platforms that differ by the field lifetime, system...

  10. Exergetic assessment of energy systems on North Sea oil and gas platforms

    International Nuclear Information System (INIS)

    Nguyen, Tuong-Van; Pierobon, Leonardo; Elmegaard, Brian; Haglind, Fredrik; Breuhaus, Peter; Voldsund, Mari

    2013-01-01

    Oil and gas platforms in the North Sea region are associated with high power consumption and large CO 2 -emissions, as the processing and utility plants suffer from significant changes in production rates and performance losses over the field lifespan. In this paper, a generic model of the overall offshore system is described: its thermodynamic performance is assessed by performing an exergy accounting and rules of thumb for oil and gas platforms are derived. Simulations are built and conducted with the tools Aspen Plus ® , Dynamic Network Analysis and Aspen HYSYS ® . 62–65% of the total exergy destruction of an offshore platform is attributable to the power generation and waste heat recovery system, and 35–38% to the oil and gas processing. The variability of the feed composition has little effect on the split of the thermodynamic irreversibilities between both plants. The rejection of high-temperature gases from the utility and flaring systems is the major contributor to the exergy losses. These findings suggest to focus efforts on a better use of the waste heat contained in the exhaust gases and on the ways in which the gas compression performance can be improved. - Highlights: • North Sea oil and gas platforms are investigated and a generic model is developed. • Exergy analysis of these offshore facilities is performed. • Most of the total exergy destruction is attributable to the utility systems producing the electrical power required onsite. • Rejection of the exhaust gases from the utility systems is the major exergy loss of this system. • The highest thermodynamic performance is reached with low well-fluid content of water and gas

  11. Exergetic assessment of energy systems on North Sea oil and gas platforms

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tuong-Van [Section of Thermal Energy, Department of Mechanical Engineering, Technical University of Denmark, Building 403, Nils Koppels Allé, 2800 Kongens Lyngby (Denmark); Pierobon, Leonardo; Elmegaard, Brian; Haglind, Fredrik [Section of Thermal Energy, Department of Mechanical Engineering, Technical University of Denmark, Building 403, Nils Koppels Allé, 2800 Kongens Lyngby (Denmark); Breuhaus, Peter [Department of Energy, International Research Institute of Stavanger, Professor Olav Hanssens vei 15, 4021 Stavanger (Norway); Voldsund, Mari [Department of Chemistry, Norwegian University of Science and Technology, Høgskoleringen 5, 7491 Trondheim (Norway)

    2013-12-01

    Oil and gas platforms in the North Sea region are associated with high power consumption and large CO{sub 2}-emissions, as the processing and utility plants suffer from significant changes in production rates and performance losses over the field lifespan. In this paper, a generic model of the overall offshore system is described: its thermodynamic performance is assessed by performing an exergy accounting and rules of thumb for oil and gas platforms are derived. Simulations are built and conducted with the tools Aspen Plus{sup ®}, Dynamic Network Analysis and Aspen HYSYS{sup ®}. 62–65% of the total exergy destruction of an offshore platform is attributable to the power generation and waste heat recovery system, and 35–38% to the oil and gas processing. The variability of the feed composition has little effect on the split of the thermodynamic irreversibilities between both plants. The rejection of high-temperature gases from the utility and flaring systems is the major contributor to the exergy losses. These findings suggest to focus efforts on a better use of the waste heat contained in the exhaust gases and on the ways in which the gas compression performance can be improved. - Highlights: • North Sea oil and gas platforms are investigated and a generic model is developed. • Exergy analysis of these offshore facilities is performed. • Most of the total exergy destruction is attributable to the utility systems producing the electrical power required onsite. • Rejection of the exhaust gases from the utility systems is the major exergy loss of this system. • The highest thermodynamic performance is reached with low well-fluid content of water and gas.

  12. Assessment of undiscovered conventional oil and gas resources in the West Korea Bay–North Yellow Sea Basin, North Korea and China, 2017

    Science.gov (United States)

    Schenk, Christopher J.; Tennyson, Marilyn E.; Mercier, Tracey J.; Hawkins, Sarah J.; Finn, Thomas M.; Gaswirth, Stephanie B.; Marra, Kristen R.; Klett, Timothy R.; Le, Phuong A.; Leathers-Miller, Heidi M.; Woodall, Cheryl A.

    2017-07-11

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable conventional resources of 1.1 billion barrels of oil and 2.2 trillion cubic feet of gas in the West Korea Bay–North Yellow Sea Basin, North Korea and China.

  13. CO2 Enhanced Oil Recovery from the Residual Zone - A Sustainable Vision for North Sea Oil Production

    Science.gov (United States)

    Stewart, Jamie; Haszeldine, Stuart; Wilkinson, Mark; Johnson, Gareth

    2014-05-01

    This paper presents a 'new vision for North Sea oil production' where previously unattainable residual oil can be produced with the injection of CO2 that has been captured at power stations or other large industrial emitters. Not only could this process produce incremental oil from a maturing basin, reducing imports, it also has the capability to store large volumes of CO2 which can offset the emissions of additional carbon produced. Around the world oil production from mature basins is in decline and production from UK oil fields peaked in 1998. Other basins around the world have a similar story. Although in the UK a number of tax regimes, such as 'brown field allowances' and 'new field allowances' have been put in place to re-encourage investment, it is recognised that the majority of large discoveries have already been made. However, as a nation our demand for oil remains high and in the last decade imports of crude oil have been steadily increasing. The UK is dependent on crude oil for transport and feedstock for chemical and plastics production. Combined with the necessity to provide energy security, there is a demand to re-assess the potential for CO2 Enhanced Oil Recovery (CO2-EOR) in the UK offshore. Residual oil zones (ROZ) exist where one of a number of natural conditions beyond normal capillary forces have caused the geometry of a field's oil column to be altered after filling [1]. When this re-structuring happens the primary interest to the hydrocarbon industry has in the past been in where the mobile oil has migrated to. However it is now considered that significant oil resource may exist in the residual zone play where the main oil column has been displaced. Saturations within this play are predominantly close to residual saturation (Sr) and would be similar to that of a water-flooded field [2]. Evidence from a number of hydrocarbon fairways shows that, under certain circumstances, these residual zones in US fields are comparable in thickness to the

  14. Assessing, planning, and management of North Sea oil development effects in the Shetland Islands

    International Nuclear Information System (INIS)

    Nelson, J.G.; Butler, R.W.

    1993-01-01

    The Shetland Islands have long had the reputation of having planned and managed the onshore effects of offshore petroleum development very well. The islands are seen as something of a model for others to follow and have frequently been visited since the beginning of northern North Sea oil development in the early 1970s by those wishing to learn how to best approach offshore petroleum development in their home areas. In this assessment the authors wish to focus on views expressed on the effectiveness of the planning and managing of onshore effects of petroleum development and present an overview of interviewee statements on future issues. Emphasis will be placed on the environmental aspects, where that term is taken for present purposes, to include fauna, flora, water quality, and other resources and their relationships to industries such as fishing and tourism--although observations will also be made about planning and management of land use and socio-economic effects. The paper concludes with an attempt to set their findings in a broader pluralist context by relating them to the views expressed in recent books by Shetland residents that contain observations on oil effects although written for more general purposes

  15. Development of an operational digital photogrammetric system for the North Sea oil and gas industry

    Science.gov (United States)

    Turner, John

    1993-02-01

    The Offshore Oil and Gas Industry in the North Sea has many requirements for three- dimensional measurements in air and underwater. A market audit found that use of conventional photogrammetry was being rejected for many applications because the information was not available fast enough. A development project was set up to replace the photographic cameras with a choice of video or high resolution digital electronic cameras, and the analysis system with a personal computer based image processing system. This solution is now in operation. The paper details the in-house development of the high resolution digital electronic camera and the personal computer based measurement hardware and software. It includes a discussion of the technological parameters, including the method for pixel for pixel correlation within the digital system, camera calibration techniques, the system algorithms, sub-pixel measurement and dimensional accuracy. It introduces the work that was carried out to make the final product acceptable to structural engineers, who now use it to transfer three- dimensional measurements to their CAD systems. It also looks at the work that is being carried out to transform the system into a closed loop control system for underwater robotic manipulators, which includes binary conversion, convolution filtering and tracking functions.

  16. Modeling North Sea oil-based mud cuttings discharges to assess environmental loading: An E ampersand P forum study

    International Nuclear Information System (INIS)

    Brandsma, M.G.; McKelvie, S.

    1994-01-01

    Oil concentrations in the water column and benthic sediments caused by the discharge of oily cuttings were predicted at four North Sea sites using a computer model. The cuttings were drilled with oil based mud and were treated to reduce oil content prior to discharge. The predictions allowed the results of biological experiments to be related to field conditions in a multi-disciplinary research project. The goal of the project was to determine what amount of oil remaining on the cuttings is environmentally acceptable. Model results suggested that treatment reduced maximum and average oil concentrations in benthic sediments by more than 93%. Frequently, the maximum concentration was reduced below the 1,000 ppm identified in the biological experiments as the sediment oil concentration above which significant effects on biological communities may be observed. Reductions of oil concentrations in the cuttings were accompanied by reduced particle sizes and settling velocities. This resulted in increased dispersion at the seabed and caused water column oil concentrations to increase. The increased water column concentrations were still several orders of magnitude below toxic levels

  17. Can Producing Oil Store Carbon? Greenhouse Gas Footprint of CO2EOR, Offshore North Sea.

    Science.gov (United States)

    Stewart, R Jamie; Haszeldine, R Stuart

    2015-05-05

    Carbon dioxide enhanced oil recovery (CO2EOR) is a proven and available technology used to produce incremental oil from depleted fields while permanently storing large tonnages of injected CO2. Although this technology has been used successfully onshore in North America and Europe, there are currently no CO2EOR projects in the United Kingdom. Here, we examine whether offshore CO2EOR can store more CO2 than onshore projects traditionally have and whether CO2 storage can offset additional emissions produced through offshore operations and incremental oil production. Using a high-level Life Cycle system approach, we find that the largest contribution to offshore emissions is from flaring or venting of reproduced CH4 and CO2. These can already be greatly reduced by regulation. If CO2 injection is continued after oil production has been optimized, then offshore CO2EOR has the potential to be carbon negative--even when emissions from refining, transport, and combustion of produced crude oil are included. The carbon intensity of oil produced can be just 0.056-0.062 tCO2e/bbl if flaring/venting is reduced by regulation. This compares against conventional Saudi oil 0.040 tCO2e/bbl or mined shale oil >0.300 tCO2e/bbl.

  18. Exergy destruction and losses on four North Sea offshore platforms: A comparative study of the oil and gas processing plants

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian

    2014-01-01

    The oil and gas processing plants of four North Sea offshore platforms are analysed and compared, based on the exergy analysis method. Sources of exergy destruction and losses are identified and the findings for the different platforms are compared. Different platforms have different working...... conditions, which implies that some platforms need less heat and power than others. Reservoir properties and composition vary over the lifetime of an oil field, and therefore maintaining a high efficiency of the processing plant is challenging. The results of the analysis show that 27%-57% of the exergy...... destruction take place in the gas treatment sections, 13%-29% take place in the gas recompression sections and 10%-24% occur in the production manifolds. The exergy losses with flared gas are significant for two of the platforms. The exact potential for energy savings and for enhancing system performances...

  19. The pollution of the North Sea

    International Nuclear Information System (INIS)

    1981-01-01

    The subject is covered in chapters entitled: the North Sea and its rivers; the uses of the North Sea (shipping; exploitation of oil and gas; fishing; recreation; land reclamation; industrial islands; waste dumping); the nature of the dumping problem (nuclear waste; organic chemicals; inorganic chemicals; oil; sewage; rubble and dredged spoils; ash); pollution legislation; Greenpeace activities in the North Sea (the nuclear campaigns (Windscale; Cap de la Hague; Atlantic waste dumping); the chemical campaigns); what is needed in the future; references; the Oslo Convention. (U.K.)

  20. Off-shore enhanced oil recovery in the north sea: matching CO_2 demand and supply given uncertain market conditions

    Science.gov (United States)

    Compernolle, Tine; Welkenhuysen, Kris; Huisman, Kuno; Piessens, Kris; Kort, Peter

    2015-04-01

    Introduction CO2 enhanced oil recovery (CO2-EOR) entails the injection of CO2 in mature oil fields in order to mobilize the oil. In particular, the injected CO2 reduces the oil's viscosity and acts as a propellant, resulting in an increased oil extraction rate (Leach et al., 2011). Given uncertainty in both oil price and CO2 price under the EU ETS system, aim of this study is to analyze under which economic conditions a CO2 exchange can be established between a CO2 supplier (an electricity producer for whom CO2 is a by-product) and a CO2 user (an offshore oil company that exploits oil fields in the North Sea and needs CO2 for enhanced oil recovery). Methodology A techno-economic simulation tool, PSS IV, was developed to provide investment decision support on integrated CO2-EOR projects (Welkenhuysen et al., 2014). Until now, a fixed onshore supply of CO2 was presumed. An economic optimization model is now developed for both the CO2 producer and the CO2 user. Because net present value and discounted cash flow methods are inadequate to deal with issues like uncertainty and the irreversibility of an investment decision, the real options theory is applied (Dixit and Pindyck, 1994). The way in which cooperation between the companies can take place, will be studied using game theoretical concepts (Lukas and Welling, 2014). Economic and technical data on CO2 capture are available from the PSS database (Piessens et al., 2012). Data on EOR performance, CO2 requirements and various costs are taken from literature (BERR, 2007; Klokk et al., 2010; Pershad et al., 2012). Results/Findings It will be shown what the impact of price uncertainty is on the investment decision of the electricity producer to capture and sell CO2, and on the decision of the oil producer to make the necessary investments to inject CO2 for enhanced oil recovery. Based on these results, it will be determined under which economic conditions a CO2 exchange and transport can take place. Furthermore, also the

  1. Probing the intrinsically oil-wet surfaces of pores in North Sea chalk at subpore resolution

    DEFF Research Database (Denmark)

    Hassenkam, Tue; Skovbjerg, Lone Lindbæk; Stipp, Susan Louise Svane

    2009-01-01

    been drilled in a water-bearing formation. At this site, the chalk has never seen oil, though at other locations, the same stratigraphic horizon with the same rock properties is known to be a productive oil reservoir. Thus the properties of the investigated particle surfaces are inherent to the chalk......Ultimate Oil recovery from chalk reservoirs is limited by many factors - including the grain size and the surface properties of the small mainly biogenic calcite particles that chalk is made off . Wettability, the tendency for water or oil to spread over a surface, of the particle surfaces is one...... of the controlling factors for the effectiveness of water flooding, one of the most common methods to improve oil recovery in Chalk reservoirs. Understanding surface wetting and its variability at scales smaller than the pore dimension will potentially provide clues for more effective oil production methods. We used...

  2. Investigation of spore forming bacterial flooding for enhanced oil recovery in a North Sea chalk Reservoir

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna

    2015-01-01

    Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focuses on core flooding experiments designed to see microbial plugging and its effect on oil recovery. A pressure tapped core holder was used for this purpose. A spore forming bacteria...... Bacillus licheniformis 421 was used as it was shown to be a good candidate in a previous study. Bacterial spore can penetrate deeper into the chalk rock, squeezing through the pore throats. Our results showed that injection of B. licheniformis 421 as a tertiary oil recovery method, in the residual oil...... saturation state, was able to produce additionally 1.0-2.3% original oil in place (OOIP) in homogeneous cores and 6.9-8.8% OOIP in heterogeneous cores. In addition, the pressure gradient was much higher in the heterogeneous cores, which confirms that bacterial selective plugging plays an important role...

  3. Thermodynamic Performance Indicators for Offshore Oil and Gas Processing: Application to Four North Sea Facilities

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian

    2014-01-01

    Well-defined performance indicators can motivate optimal operation of offshore oil and gas platforms. We evaluate several thermodynamic performance indicators presented in the literature according to three criteria: Thermodynamic performance indicators should evaluate the use of technically...

  4. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    of the temperature dependence of the oil recovery indicated that the interaction of the ions contained in brine with the rock cannot be the only determining mechanism of enhanced recovery. We observed no substitution of Ca2+ ions with Mg2+ ions at high temperatures for both rocks. Not only the injection brine......In recent years, many core displacement experiments of oil by seawater performed on chalk rock samples have reported SO42–, Ca2+, and Mg2+ as potential determining ions for improving oil recovery. Most of these studies were carried out with outcrop chalk core plugs. The objective of this study...... is to investigate the potential of the advanced waterflooding process by carrying out experiments with reservoir chalk samples. The study results in a better understanding of the mechanisms involved in increasing the oil recovery with potential determining ions. We carried out waterflooding instead of spontaneous...

  5. Optimization of Spore Forming Bacteria Flooding for Enhanced Oil Recovery in North Sea Chalk Reservoir

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna

    2015-01-01

    .2-3.8 cm) during bacteria injection. Further seawater flooding after three days shut in period showed that permeability gradually increased in the first two sections of the core and started to decrease in the third section of the core (3.8-6.3 cm). Complete plugging was never observed in our experiments.......Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focused on core flooding experiments to see microbial plugging and its effect on oil recovery. A pressure tapped core holder with pressure ports at 1.2 cm, 3.8 cm, and 6.3 cm from the inlet...

  6. Exergetic assessment of energy systems on North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Pierobon, Leonardo; Elmegaard, Brian

    2013-01-01

    offshore system is described: its thermodynamic performance is assessed by performing an exergy accounting and rules of thumb for oil and gas platforms are derived. Simulations are built and conducted with the tools Aspen Plus_, Dynamic Network Analysis and Aspen HYSYS_. 62e65% of the total exergy...

  7. Modeling of phase equilibrium of North Sea oils with water and MEG

    DEFF Research Database (Denmark)

    Frost, Michael Grynnerup; Kontogeorgis, Georgios; von Solms, Nicolas

    2016-01-01

    The complex phase equilibrium between reservoir fluids and associating compounds like water and glycols has become very important as the increasing global energy demand pushes the oil industry to use advanced methods to increase oil recovery, such as increasing the use of various chemicals...... to ensure a constant and safe production. The CPA equation of state has been successfully applied in the past to well defined systems and gas condensates containing associating compounds. It has also been extended to reservoir fluids in presence of water and polar chemicals using modified correlations...... for critical temperature, pressure and acentric factor.In this work, we evaluate CPA using recently developed correlations for predicting the binary interaction parameters between MEG/hydrocarbons and water/hydrocarbons, for a wide range of systems containing reservoir fluids and production chemicals...

  8. World crude oil prices and the North Sea after the Gulf conflict

    International Nuclear Information System (INIS)

    Kemp, A.

    1992-01-01

    A large computerised financial model has been developed to simulate future activity in the United Kingdom continental shelf. Primary inputs into the model include all the publicly available information on currently producing fields relating to their historic and expected production rates, investment costs, operating costs and abandonment costs. From a variety of sources information has also been gathered on all new discoveries which have not yet been developed or even fully appraised in some cases. Estimates were made of the time periods at which such fields would be ready for development work and production to commence. For these future fields estimates were made of the likely investment costs, operating costs and abandonment costs. In making such calculations only limited technological progress was assumed. The bank of future fields is also conservative as it does not include any new discoveries from further exploration successes. Key inputs into the financial model are future oil and gas price scenarios. In this study, three price scenarios have been chosen for investigation - a base case, a high price case and a low price case. From the analysis, the possible consequences of a very modest real growth in oil and gas prices on the development of the very large numbers of discovered, but as yet undeveloped, oil and gas fields in the United Kingdom continental shelf are presented. (author)

  9. Composition and dynamics of biostimulated indigenous oil-degrading microbial consortia from the Irish, North and Mediterranean Seas: a mesocosm study.

    Science.gov (United States)

    Gertler, Christoph; Näther, Daniela J; Cappello, Simone; Gerdts, Gunnar; Quilliam, Richard S; Yakimov, Michail M; Golyshin, Peter N

    2012-09-01

    Diversity of indigenous microbial consortia and natural occurrence of obligate hydrocarbon-degrading bacteria (OHCB) are of central importance for efficient bioremediation techniques. To investigate the microbial population dynamics and composition of oil-degrading consortia, we have established a series of identical oil-degrading mesocosms at three different locations, Bangor (Menai Straits, Irish Sea), Helgoland (North Sea) and Messina (Messina Straits, Mediterranean Sea). Changes in microbial community composition in response to oil spiking, nutrient amendment and filtration were assessed by ARISA and DGGE fingerprinting and 16Sr RNA gene library analysis. Bacterial and protozoan cell numbers were quantified by fluorescence microscopy. Very similar microbial population sizes and dynamics, together with key oil-degrading microorganisms, for example, Alcanivorax borkumensis, were observed at all three sites; however, the composition of microbial communities was largely site specific and included variability in relative abundance of OHCB. Reduction in protozoan grazing had little effect on prokaryotic cell numbers but did lead to a decrease in the percentage of A. borkumensis 16S rRNA genes detected in clone libraries. These results underline the complexity of marine oil-degrading microbial communities and cast further doubt on the feasibility of bioaugmentation practices for use in a broad range of geographical locations. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  10. A tax reprieve for the North Sea?

    International Nuclear Information System (INIS)

    Kemp, A.

    1998-01-01

    The United Kingdom government has for the time being put to one side its intended review of the fiscal regime in the North Sea. Consistently low oil prices over the last year and the consequent effect on production have given rise to this decision. The ongoing debate on oil taxation in the UK over the past 18 months since the advent of a new government is examined. It has its roots in the last major changes to the oil tax regime which were made in 1993. It has been made clear by the government that the taxation review has not been abandoned and could come to the fore again should there be a substantial increase in oil and gas prices or if companies sought premature decommissioning of North Sea fields. (UK)

  11. The occurrence of the cold-water coral Lophelia pertusa (Scleractinia) on oil and gas platforms in the North Sea: Colony growth recruitment and environmental controls on distribution

    Energy Technology Data Exchange (ETDEWEB)

    Gass, S.E.; Roberts, J.M. [Scottish Association for Marine Science, Dunstaffnage Marine Laboratory, Oban, Argyll (United Kingdom)

    2006-05-15

    This study reports a newly established sub-population of Lophelia pertusa, the dominant reef-framework forming coral species in the north-east Atlantic, on oil and gas platforms in the northern North Sea. L. pertusa was positively identified on 13 of 14 platforms examined using existing oil and gas industry visual inspections. Two platforms were inspected in more detail to examine depth and colony size distributions. We recorded 947 colonies occurring between 59 and 132 m depth that coincides with cold Atlantic water at depths below the summer thermocline in the northern North Sea. We suggest that these colonies provide evidence for a planktonic larval stage of L. pertusa with recruits initially originating from populations in the north-east Atlantic and now self recruiting to the platforms. Size class distribution showed a continuous range of size classes, but with few outlying large colonies. The break between the largest colonies and the rest of the population is considered as the point when colonies began self recruiting to the platforms, resulting in greater colonization success. We present the first documented in situ colony growth rate estimate (26 {+-} 5 mm yr{sup -1}) for L. pertusa based on 15 colonies from the Tern Alpha platform with evidence for yearly recruitment events starting the year the platform was installed. Evidence of contamination from drill muds and cuttings was observed on the Heather platform but appeared limited to regions close to drilling discharge points, where colonies experience partial as well as whole colony mortality. (author)

  12. The North Sea Bird Club

    International Nuclear Information System (INIS)

    Doyle, P.A.T.; Gorman, M.L.; Patterson, I.J.; Howe, S.

    1991-01-01

    This paper reports that the creation of a club for the purpose of encouraging oil and gas workers to watch birds may not at first seem a viable proposition. To the layperson, birds offshore conjures up an image of hundreds of seagulls following fishing boats, and very little else. Also, the act of birdwatching is not seen as a typical offshore worker's activity. Anyone who has worked on an installation offshore and who has any interest in wildlife will be aware of the occasional presence of land-birds. Two decades ago, prompted by some keen offshore workers, a single oil company set up a monitoring program, which quickly became popular with a number of its employees. Birds seem offshore were recorded on data forms and collected together. At this stage the club was purely another recreation facility; however, when the data were collated it was soon realized that installations offshore were being used as staging posts by birds on migration, and that the information being collected would be of great interest in the study of bird movements. All over Britain, at strategic points on the coastline, there are bird observatories which record the arrival and departure of migrating birds. The presence of several hundred solid structures up and down the North Sea, which are used by birds en route, represents a huge, unique bird observatory, capable of uncovering facts about bird migration which have long eluded land-based scientists. Eleven years ago, the North Sea Bird Club began, composed of eight member companies, a recorder from Aberdeen University and a representative from the Nature Conservancy Council. The club received data from 41 installations, and the recorder collated these on Aberdeen University's computer and produced an annual report of sightings

  13. The Impact of Tax Shocks and Oil Price Volatility on Risk - A Study of North Sea Oilfield Projects

    OpenAIRE

    Kretzschmar, Gavin Lee; Moles, Peter

    2006-01-01

    We examine the impact of market volatility and increased fiscal take on risk in strategic natural resource projects. An increase in 2006 UK oilfield taxation is used as a natural experiment for assessing the impact of a fiscal increase on oilfield projects comprising 73% of UK reserves. Stochastic cash flow at risk models combine market volatility and tax-take at the oilfield level to extend earlier North Sea studies. We demonstrate that a 10% Secondary tax increase in a composite UKCS fiscal...

  14. Report from Holland: the economics of North Sea hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Ellman, M

    1977-09-01

    The article describes how, despite huge revenues from North Sea gas, Holland is currently suffering from unemployment and its long-term prospects are poor. In light of this, Mr. Ellman discusses the implications of North Sea oil for the UK economy. He sites three distinguishable policies that the UK government could adopt in the face of the huge import saving and export creation that North Sea hydrocarbons will soon bring--sound finance, demand management, and structural modernization. (MCW)

  15. Rural population mixing and childhood leukaemia: effects of the North Sea oil industry in Scotland, including the area near Dounreay nuclear site

    International Nuclear Information System (INIS)

    Kinlen, L.J.; O'Brien, F.; Clarke, K.; Balkwill, A.; Matthews, F.

    1993-01-01

    The objective of this study was to determine if any excess of childhood leukaemia and non-Hodgkin's lymphoma was associated with certain striking examples of population mixing in rural Scotland produced by the North Sea oil industry. Details were traced for over 30 000 workers (25 yrs old) involved in the construction of the large oil terminals in the Shetland and Orkney islands in northern Scotland or employed offshore. Home addresses of the 17160 Scottish residents were postcoded, integrated with census data, and then classified as urban or rural. Rural postcode sectors, ranked by proportion of oil workers, were grouped into three categories with similar numbers of children but contrasting densities of oil workers. The incidence of leukaemia and non-Hodgkin's lymphoma was examined in these rural (and also in urban) categories in the periods 1974-8, 1979-83 and 1984-8. A significant excess of leukaemia and non-Hodgkin's lymphoma was found in 1979-83 in the group of rural home areas with the largest proportion of oil workers, following closely on large increases in the workforce. The area near the Dounreay nuclear installation, where an excess of leukaemia is already well known, was within the rural high oil category. (Author)

  16. 3d Operational Hydrodinamic Modelling System as a Support to Oil Spill Responses in the Ligurian Sea (North-Western Mediterranean)

    Science.gov (United States)

    Del Giudice, T.; Quagliati, M.; Bertolotto, R.; Pedroncini, A.; Cusati, L. A.

    2014-12-01

    Accidental oil spills have a significant impact on marine ecosystems reminding us the importance of an efficiency emergency planning to ensure a quick and proper response. In this phase, the numerical modelling approach emerges as a useful tool in order to simulate the scenarios and addresses the issue of oil dispersion in the case of a spill. The 3D operational hydrodynamic modelling system of the Ligurian Sea (North-Western Mediterranean) is used as a base to predict the possible oil trajectory and to track the path and fate of spilled oil under the prevailing hydrodynamic and meteorological conditions. The operative chain of the hydrodynamic model was developed by DHI Italia for the Regional Environment Protection Agency (ARPAL) operating in the Ligurian region (Italy) with the objective to preserve the environment, support the activities of the Civil Protection Department and promote a sustainable, healthy and safety management of the local resources. In this chain the MFS Mediterranean 3D model (operated within MyOcean EU Project - Copernicus Programme) was downscaled from 6.5 km to finer nearshore mesh (500 m). The increased spatial resolution allows the correct simulation of current developments in the vicinity of morphological discontinuities such as the promontory of Portofino on the Ligurian coast. The meteorological forcing is provided by MOLOCH, a LAM model operated by ARPAL together with fresh water discharges from the main rivers through hydrological modelling. Since the Ligurian Sea recently hosted the transfer of wreck Costa Concordia some real time simulations of hypothetical oil spill were performed to support the crisis unit of the Genoa Coast Guard. Simulations led to interesting results concerning the importance of updated weather conditions, which strongly influence current trends, focusing on the importance of the continuity of the modelling chain.

  17. Worldwide market forces threaten North Sea wealth

    Energy Technology Data Exchange (ETDEWEB)

    Booth, D

    1977-01-01

    The challenges that the petroleum industry faces in winning all the oil resources in the North Sea are reviewed. All these hydrocarbons that will soon sustain governments, bolster the standard of living, and bring profits to investors will one day be gone, perhaps. The author says, ''if demand for oil continues to rise by a few percent each year for the next 25 years the prospect of the North Sea drained of its riches is real. Even if Britain makes no more demands on it than those needs of today, the global concept of the oil business will mean that other markets will place the North Sea reserves at risk of exhaustion. Two major factors affect this assumption: market forces and government-implemented depletion rates.'' After explaining these two assumptions, the author graphically portrays what life will be like when petrol becomes a luxury item. It is forgotten that the hydrocarbons are being consumed in a lifetime, when it took several millions of years to put them together. (MCW)

  18. Opportunities for suppliers in the North Sea

    International Nuclear Information System (INIS)

    D'Ancona, J.E.

    1992-01-01

    If European suppliers to the offshore industry are to prosper, it has to be on the basis of a single internationally competitive North Sea market. If we continue to talk and think in terms of a British sector, a Norwegian sector, Dutch and Danish sectors, then we will inhibit the full development of contractors and suppliers. The long term future in oilfield supplies lies in a mixed portfolio of international projects. Oil and gas exploration and development, particularly offshore, is notoriously cyclical. To survive the downturns in one market supply, companies need to have access to the upswing in others. The significance of a single North Sea market is that it presents an international arena for the best companies to demonstrate their technical and commercial abilities. Individual national sectors do not - cannot - provide that opportunity to anything like the same extent. Taking then the North Sea as a single competitive market, it represents the most important offshore area in the world at the present time, and this is likely to continue during the 1990s. The prospects of achieving a single North Sea market are discussed. (author)

  19. North American oil demand outlook

    International Nuclear Information System (INIS)

    Stewart, M.B.

    1995-01-01

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC's pricing power. Such price increases could depress North American oil demand growth. (author)

  20. Air-sea exchange studies at the North Sea

    NARCIS (Netherlands)

    Leeuw, G. de; Eijk, A.M.J. van; Kunz, G.J.; Veefkind, P.J.

    1996-01-01

    The North Sea can be considered as a local 'inner' sea in which many processes are quite different from these over the open ocean. The surrounding land has a major influence, being the source for man-made aerosols and gases, whereas the North Sea acts as a sink for these. At the same time the North

  1. Management and control of microbiologically influenced corrosion (MIC) in the oil and gas industry-Overview and a North Sea case study.

    Science.gov (United States)

    Skovhus, Torben Lund; Eckert, Richard B; Rodrigues, Edgar

    2017-08-20

    the conflicting historic results obtained through serial dilution of culture media using the most probable number (MPN) method as compared to data obtained from corrosion monitoring and the quantitative polymerase chain reaction (qPCR) method. Results from qPCR application in the field case have changed the way MIC is monitored on the oil production facility in the North Sea. A number of high quality resources have been published as technical conference papers, books, educational videos and peer-reviewed scientific papers, and thus we end the review with an updated list of state-of-the-art resources for anyone desiring to become more familiar with the topic of MIC in the upstream oil and gas sector. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Petroleum Economist's 1993 North Sea survey

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A survey is presented for 51 oil fields in the North Sea belonging to the United Kingdom, 17 belonging to Norway, 4 belonging to the Netherlands and 7 belonging to Denmark. Similarly data is presented for 32 gas fields belonging to the United Kingdom, 5 belonging to Norway, 42 belonging to the Netherlands, and 1 belonging to Denmark. The information given in the surveys includes the original recoverable reserves, remaining reserves, water depth, gravity, sulphur content, discovery date, start-up date, participants and production. (U.K.)

  3. The North Sea field development guide. V.1: Northern North Sea. V.2: Southern North Sea. 6. ed.

    International Nuclear Information System (INIS)

    Anon.

    1996-08-01

    The 1997/8, sixth edition is the first to be divided into two volumes. Volume 1 covers the central and northern North Sea areas; volume 2 contains the southern North Sea as well as the Irish and German sectors. The pages are numbered consecutively over the two volumes, with page numbers greater than 702 contained in the second volume. There are three index sections. Main index. Arranged by national sector (UK, Norway etc.) Within each sector the entries are alphabetical by operator name. This index contains page numbers for the book entries: the other two index sections should be used with the main index to find the exact location of an entry; Index by field. If the reader knows a field name (e.g. Kittiwake) but not the operator or the national sector, this index will reference them; Index by installation. Each installation (''Fulmar SALM'', ''Togi'') is named, giving the operator, field and national sector where it is located. This index is also useful for locating particular kinds of installations, such as subsea completions; The book is intended to provide a factual overview of field development activity in the North Sea (a term loosely used to include the Irish Sea and the Baltic Sea). The aim is therefore to provide some background, specifications and history on every offshore installation in that area. Speculative or evaluative commentary is avoided where possible. No attempt has been made to forecast the form or probability of future developments, except in those few instances where announcements have been made by the oil company itself, and these are, clearly indicated. (UK)

  4. Off-shore enhanced oil recovery in the North Sea : The impact of price uncertainty on the investment decisions

    NARCIS (Netherlands)

    Compernolle, T.; K, Welkenhuysen,; Huisman, Kuno; K, Piessens,; Kort, Peter

    2017-01-01

    Although CO2 Capture and Storage (CCS) is considered a key solution for CO2 emission mitigation, it is currently not economically feasible. CO2 enhanced oil recovery can play a significant role in stimulating CCS deployment because CO2 is used to extract additional quantities of oil. This study

  5. Distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea

    International Nuclear Information System (INIS)

    Bruns, K.; Dahlmann, G.; Gunkel, W.

    1993-01-01

    Data were collected in 1988 and 1989 on the distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea. Crude oil degrading bacteria and the number of bacteria which in particular degrade naphthalene were quantified using a modified dilution method (MPN). Crude oil degrading bacteria were present in all of about 100 water samples, with as many as 10 3 ml -1 in some samples. Numbers of naphthalene degrading bacteria were at least tenfold lower. There is obviously a greater connection between this bacteria group and petroleum hydrocarbon (PHC) contamination than between the more nonspecific group of crude oil degrading bacteria and PHC contamination. Data from the North Sea show an extremely high abundance of hydrocarbon degrading bacteria, even in winter, while in the southern Baltic Sea low numbers of bacteria were found and slower crude oil degradation was observed. (orig.)

  6. Off-shore enhanced oil recovery in the North Sea: The impact of price uncertainty on the investment decisions

    International Nuclear Information System (INIS)

    Compernolle, T.; Welkenhuysen, K.; Huisman, K.; Piessens, K.; Kort, P.

    2017-01-01

    Although CO_2 Capture and Storage (CCS) is considered a key solution for CO_2 emission mitigation, it is currently not economically feasible. CO_2 enhanced oil recovery can play a significant role in stimulating CCS deployment because CO_2 is used to extract additional quantities of oil. This study analyzes the investment decision of both a carbon emitting source and an oil company separately by adopting a real options approach. It is shown that when uncertainty is integrated in the economic analysis, CO_2 and oil price threshold levels at which investments in CO_2 capture and enhanced oil recovery will take place, are higher than when a net present value approach is adopted. We also demonstrate that a tax on CO_2 instead of an emission trading system results in a lower investment threshold level for the investment in the CO_2 capture unit. Furthermore, we determine a minimum CO_2 selling price between the two firms and show that CO_2-EOR has the potential to pull CCS into the market by providing an additional revenue on the capture plant. However, when CO_2 permit prices are above an identifiable level, the EU ETS does not necessarily result in the adoption of CCS and stimulates oil production. - Highlights: • Real options theory is applied to study how uncertainty affects CO2EOR investments. • Compared to an NPV approach, investment threshold levels are higher. • A tax on CO2 would result in lower investment threshold levels compared to EUETS. • A minimum CO2 selling price is determined • The CO2 needed for enhanced oil recovery is not necessarily a cost.

  7. The North Sea contracting industry

    International Nuclear Information System (INIS)

    Wright, P.J.C.

    1996-09-01

    The North Sea Contracting Industry provides in-depth profiles of major contracting organisations including manpower, facilities, expertise, future directions and financial details. It addresses key issues such as: how will the role of operators and contractors change toward 2000 and beyond?; how will the contractor-operator relationship develop?; will the contractors take a more speculative role in projects such as leasing and contract to produce?; does the future belong to broad skilled providers or small specialised niche players, or both?; and how will rapid technological improvements affect the industry? (author)

  8. Oil and the Caspian Sea

    International Nuclear Information System (INIS)

    Mohammad Poure Daryaei, N.

    2000-01-01

    Caspian Sea is the biggest lake in the world. It is almost F-shape and located between five Countries of Iran, Turkmenistan, Russia, Azarbayjohn, Ghazaghestan. Un fortunately, in the different region of the sea there are highly contaminated oil, in addition with other source of pollutants such as: agricultural, industrial and domestic pollution, which causes to eliminate the natural habitats of aquatic life and thus, the Caspian sea with all of the valuable natural sources of foods and energy is close to be destroyed. This paper studies the pollution by oil industry which causes the elimination of aquatic life and natural ecosystem, as well as, necessary plan to over come the present situation

  9. North Africa oil and gas

    International Nuclear Information System (INIS)

    Priddle, R.

    1996-01-01

    During the last decade, Algeria, Egypt and Libya have improved their fiscal terms for oil and gas development to attract more investment in this area. As a group, the three countries are implementing plans to increase crude oil production capacity 16 % from 3.15 million barrels per day (Mb/d) in 1995 to 3.65 Mb/d in the year 2000. Natural gas liquid are also being developed and their production capacity is planned to increase 30 % to 0.82 Mb/d in 2000. Concurrently, natural gas production capacity is being expanded about 50 % by 200 and natural gas exporting capacity should see a 92 % increase in 2000 over 1995 levels in short, the North Africa hydrocarbon producers are rapidly expanding their production and export capacity of gaseous and liquid hydrocarbons. This is the first IEA study to focus on North Africa. It shows how changing hydrocarbon legislation or production sharing agreements can result in changes in crude oil and natural gas production capacity. Much of the expansion outlined in this study is being guided by international oil companies attracted by the improved fiscal terms

  10. The carbon budget of the North Sea

    NARCIS (Netherlands)

    Thomas, H.; Bozec, Y.; Baar, H.J.W. de; Elkalay, K.; Frankignoulle, M.; Schiettecatte, L.-S.; Kattner, G.; Borges, A.V.; Gattuso, J.-P.

    2005-01-01

    A carbon budget has been established for the North Sea, a shelf sea on the NW European continental shelf. The carbon exchange fluxes with the North Atlantic Ocean dominate the gross carbon budget. The net carbon budget – more relevant to the issue of the contribution of the coastal ocean to the

  11. Environmental assessment after decommissioning at the North Sea- Froey oil production site: a field study with biomarkers in fish and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Pinturier, Laurence; Beyer, Jonny; Moltu, Ulf; Plisson, Saune Stephan; Berland, Harald; Sundt, Rolf; Bjoernstad, Anne; Sanni, Steinar

    2006-03-15

    The Froey field is situated in the North Sea and was operated by Total Exploration and Production Norge. Oil production started in 1995 and ceased in 2001, when the wells were permanently plugged and abandoned. The jacket was removed in 2002, and in 2003 the first post-production sediment monitoring survey was carried out at the field as a part of the regional sediment environmental monitoring survey of Region II. In parallel to the sediment monitoring survey and cuttings survey, Total E and P Norge decided to conduct an environmental survey based on the use of biological effects parameters (or biomarkers) to document the environmental condition of the site after decommissioning. A series of pollutant responsive biomarkers was selected in order to answer the following questions: is the environmental condition in the bottom water at the Froey location significantly different to the background situation as measured in the reference station? And does the cutting deposit affect the nearby environment. Conclusion: This paper present a selection of the results obtained during an environmental survey carried out at a decommissioned field, the Froey field, by Total E and P Norge and RF-Akvamiljoe. Detailed results and discussion will be presented more extensively in a peer review publication by Beyer et al. (2005). The objective of the survey was to evaluate the environmental condition at the Froey site by comparing it to a background situation measured at a reference site. The environmental condition was assessed by measuring biological effects parameters in invertebrates and fish living in close connection with the sediments. The results of this survey indicate only a very local pollutant effect in the vicinity of the cuttings limited to the invertebrates living and feeding on the sediment. No signal effects were measured in the selected fish species known to swallow large quantity of sediment when feeding. These results corroborate well the ones obtained from the

  12. What is the pollution status of North Sea sediments?

    International Nuclear Information System (INIS)

    Chapman, P.M.; Heip, C.; Cofino, W.

    1993-01-01

    A March 1990 international sea-going workshop in Bremerhaven, Germany provided the opportunity to conduct detailed sediment toxicity testing in concert with studies of fish histopathology, bioaccumulation, benthic community structure, and sediment chemical contamination in the North Sea. Two gradients of sediment chemical contamination were tested, one from an abandoned oil platform and the other from the mouth of the Elbe River northward to the Dogger Bank. Using a preponderance of evidence approach, it was determined that sediments nearest the Elbe are moderately polluted (pollution is defined as contamination, toxicity, and community alteration) and that sediments offshore and at the Dogger Bank are unpolluted. Sediments nearest the oil platform showed evidence for a low level of pollution, but there was no evidence of pollution 125 m from the platform. The results suggest the testable hypothesis that North Sea sediments away from point sources of pollution such as coastal areas and drilling platforms are presently not polluted. 46 refs., 2 figs., 6 tabs

  13. Middle East and North African Oil.

    Science.gov (United States)

    Al-Quazzaz, Ayad

    1981-01-01

    Traces the history of oil and natural gas in the Middle East and relates the importance of the Middle East's current stores of oil to economic development. Information is presented on the relationship of major oil companies and local governments, OPEC, rate of production, and the impact of oil on the societies of the Middle East and North Africa.…

  14. North Sea oil and Britain's balance of payments. An investigation with the aid of a simulation model. Das Nordseeoel und die britische Zahlungsbilanz. Eine Untersuchung mit Hilfe eines Simulationsmodells

    Energy Technology Data Exchange (ETDEWEB)

    Juergensen, H [ed.

    1979-01-01

    An introduction outlining the complex of problems and discussing the chosen method is followed by the development of a computerized simulation model. Starting from oil exploration, the whole process of opening, financing, production, and taxation of discovered North Sea oil fields is analysed and modelled up to the effects they have on the balance of payments. The statements are characterized by the opinion that even formalized, complex model relations can be delivered in a way which is intelligible to all. In the final part, predicted results are presented and discussed in detail, which were achieved under conditions alternatively assumed for the future on the basis of the model calculations. Furthermore, in the annexes flowcharts and the FORTRAN program of the model as well as comprehensive tables of results are shown. With this work, the author breaks through the narrow concept of a pure simulation model. For the first time he shows opportunities and limit, the set to the restoration of Britain's balance of payments by means of North Sea oil.

  15. SeaWiFS: North Pacific Storm

    Science.gov (United States)

    2002-01-01

    An extratropical storm can be seen swirling over the North Pacific just south of Alaska. This SeaWiFS image was collected yesterday at 23:20 GMT. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  16. North Sea trends typify industry's worldwide adjustment to change

    International Nuclear Information System (INIS)

    Nicandros, C.S.

    1993-01-01

    In response to rapid industry changes, oil companies are employing new practices and entering new relationships. In the U.K. North Sea's Britannia field, Conoco (U.K.) Ltd. and Chevron (U.K.) Ltd. share duties of field operator in the region's first such business arrangement. Here, the Neddrill 6 semisubmersible drills a Britannia appraisal well. This report tells how companies are using teamwork and other techniques to derive maximum value from their assets and technologies

  17. Independent companies in the North Sea - exploration and operations opportunities

    International Nuclear Information System (INIS)

    Greentree, C.

    1992-01-01

    The North Sea was the launching pad for many independent oil companies, particularly through exploration success in the UK and the Netherlands. Norway has an excellent history of oil exploration but, for the independents, the onerous tax regime, long lead times, and terms of trade are simply not conducive to the higher rate of return demanded by shareholders of independent E and P companies in exchange for shouldering the heavy burden of risk. The UK in particular has pursued imaginative licensing, tax and legislative policies which have allowed the independents an opportunity to participate and grow. The attraction of the UK is clearly reflected by the constant arrival of new entrants, even at this stage of maturity. This was demonstrated in the recent round of license awards. Such has been the success of the independents in the UK that, beginning with virtually nothing, they now hold a net 28% of the UK North Sea acreage, and a net 25% of its oil reserves. Equally, the independents play an important role in ensuring the comprehensive exploration of the offshore areas. Because of size and significance, a prime objective of the independents will remain the early evaluation, through drilling, and development of offshore interests to generate a financial return. This paper addresses the question of how independent companies can expand in the North Sea when the size and quality of new range acreage available through new license awards is reducing. (author)

  18. Benthic community structures in the North Sea

    Science.gov (United States)

    Heip, C.; Craeymeersch, J. A.

    1995-03-01

    Coherent assemblages of marine benthic species have been recognized from the early twentieth century, and the classical papers of Petersen (1914, 1918) were based on studies of limited areas in the North Sea. In 1986, a synoptic survey of the North Sea north to 57°N was undertaken by a group of ten laboratories from seven North Sea countries. The results of this survey have recently been published (Heip et al., 1992a, b; Künitzer et al., 1992; Huys et al., 1992), and some of the results are summarized in this paper. The analysis of the macrofauna is based on slightly more than 700 taxa. In general, the North Sea macrofauna consists of northern species extending south to the northern margins of the Dogger Bank, and southern species extending north to the 100 m depth line. The central North Sea is an area of overlap of southern and northern species, especially around the 70 m depth contour. Consistent groupings of species are recognized that were summarized in seven faunal groupings. Macrofaunal body weight, density and diversity increase linearly towards the north. Macrofaunal biomass for the whole area averages 7 g adwt. m-2 and decreases from south to north. Distribution patterns and trends within the meiofauna were very different. Nematodes, which are the dominant taxon overall, are least abundant in the sandy sediments of the Southern Bight, then increase to a maximum around 53° 30' N and slowly decrease again towards the north. Copepod density and diversity are highest in the Southern Bight, due to the presence of many interstitial species. A large number of species new to science were recorded by the North Sea Benthos Survey and about 1500 species are expected to occur. Copepods show very distinct assemblages according to water depth and sediment type. The contrasting patterns in latitudinal gradients of body weight and number of species of macro- and meiofauna can be only partially explained. Latitude and sediment characteristics, such as grain size and

  19. Use of unmanned aerial vehicle (UAV) for the detection and surveillance of marine oil spills in the Belgian part of the North Sea

    International Nuclear Information System (INIS)

    Donnay, E.

    2009-01-01

    This paper discussed the use of unmanned aerial vehicles (UAV) deployed by the Belgian Army in order to detect oil spills as well as for intelligence, reconnaissance and surveillance missions. The UAV are fitted with a dual sensor gyro-stabilized turret which combines a daylight camera and a thermal infrared camera. Live images of the sensors are transmitted in real time to control stations. All Belgian marine pollution surveillance platforms are coordinated by the Maritime Security Center of the Belgian Coast Guard. Satellite surveillance services provide real time information related to potential oil spills and other anomalies on the sea surface. Stand-by helicopters are also used for the rapid assessment of reported spills. The B-Hunter system is undetectable due to its small size and low noise signature, and can be used for the continuous monitoring of specific areas or for the tracking of suspect vessels. The system will also be used to monitor the progress of oil spill response operations as well as to provide information and guidance to response vessels. 6 refs., 2 figs

  20. Use of unmanned aerial vehicle (UAV) for the detection and surveillance of marine oil spills in the Belgian part of the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Donnay, E. [Federal Public Service Health, Food Chain Safety and Environment, Brussels (Belgium)

    2009-07-01

    This paper discussed the use of unmanned aerial vehicles (UAV) deployed by the Belgian Army in order to detect oil spills as well as for intelligence, reconnaissance and surveillance missions. The UAV are fitted with a dual sensor gyro-stabilized turret which combines a daylight camera and a thermal infrared camera. Live images of the sensors are transmitted in real time to control stations. All Belgian marine pollution surveillance platforms are coordinated by the Maritime Security Center of the Belgian Coast Guard. Satellite surveillance services provide real time information related to potential oil spills and other anomalies on the sea surface. Stand-by helicopters are also used for the rapid assessment of reported spills. The B-Hunter system is undetectable due to its small size and low noise signature, and can be used for the continuous monitoring of specific areas or for the tracking of suspect vessels. The system will also be used to monitor the progress of oil spill response operations as well as to provide information and guidance to response vessels. 6 refs., 2 figs.

  1. Geology of the North Sea and Skagerrak

    Energy Technology Data Exchange (ETDEWEB)

    Michelsen, O. [ed.

    1995-12-31

    The Marine Geology Unit of the Department of Earth Sciences organized the second Marine Geology symposium at Aarhus University, 7-8 October 1993. The intention was to bring together people working especially with the geology of the North Sea and Skagerrak. Approximately 60 people from different Danish and Norwegian institutions attended the symposium. 28 oral presentations were given and 2 posters presented. A large range of geological topics was covered, embracing biostratigraphy, sequence stratigraphy, sedimentology and structural geology. The majority of the presentations dealt with Quaternary geology and Cenozoic sequence stratigraphy, but also Jurassic and Lower Cretaceous stratigraphy was treated. Studies from the major part of the Danish sector were presented, spanning from Bornholm to the central North Sea, and further into the Norwegian North Sea sector. (au)

  2. Wind fluctuations over the North Sea

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Pinson, Pierre; Giebel, Gregor

    2011-01-01

    Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms. The Hil......Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms...

  3. Tender moments in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Fox, C

    1991-04-01

    Described is tender-assisted drilling (TAD) on the UK North Sea Gannet field. The Gannet field is developed by Shell UK Exploration and Production (Shell Expro). In March 1990, Shell Expro awarded Sedco Forex the design and engineering contract to convert the semisubmersible drilling rig Sedco 704 into the Gannet TSV (Tender Support Vessel). The only semisubmersible TSV operation so far to have completed drilling in the North Sea has been in the Norwegian sector. The Odin field, operated by Esso Norge a/s, was developed using the converted drilling rig Treasure Hunter. 1 fig., 1 ill., 3 refs.

  4. Sensitivity mapping of the German North Sea Coast II. Data update and development of an operational model for precaution measures of oil spill response; Sensititivaetsraster Deutsche Nordseekueste II. Aktualisierung und Erstellung eines operationellen Modells zur Vorsorgeplanung bei der Oelbekaempfung

    Energy Technology Data Exchange (ETDEWEB)

    Bernem, K.H. van; Doerffer, R.; Heymann, K.; Kleeberg, U.; Krasemann, H.; Schiller, H. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Kuestenforschung; Grohnert, A.; Reichert, J. [IfaB - Institut fuer Angewandte Biologie Freiburg/Niederelbe (Germany); Reichert, M. [ARCADIS, Rostock (Germany)

    2007-07-01

    The Wadden Sea is an area of tidal flats and salt marshes extending between the North Sea coasts of Denmark, Germany and the Netherlands. It has enormous value as a cleansing site for North Sea water, as a nursery for young fish and as a feeding ground for many bird species. Due to the proximity of important shipping routes and harbours, this region is especially threatened by oil spills. Thus, for oil spill response and precaution measures, a sensitivity study of the entire intertidal area was badly needed in order to assess and minimize the potential ecological and economical damage. Based on comprehensive field surveys and in close cooperation with the Central Command for Maritime Emergencies, an automated expert-model for the german part of Wadden Sea areas was developed at the Institute for Coastal Research (GKSS-Research Centre). As an operational model it will serve as important instrument for decision making processes, precautionary measures and the further design of oil spill response strategies. Since it is not possible to protect the entire German North Sea coast equally at all levels, oil spill contingency planning requires a more detailed classification. For this reason, individual soft bottom habitats, communities and stocks of saltmarshes, macrofauna, waterfowl and estuarine biotop types were evaluated and classified according to their vulnerability to oil pollution. Hence, the fieldwork for habitat mapping during 2003-2006 was a central part of the study. For this part, the experiences and results obtained from the previous GKSS-project ''Thematic mapping and sensitivity study of Intertidal flats'' during the years 1987-1992 served as an valuable basis. For example, the documentation of changes during these periods of observation provides information on stability features of the ecosystems. During the first project nearly 5000 locations were processed and characterised using about 70 parameters for each site. The in-situ mapping

  5. Seabird biomass and food consumption in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Furness, R.W.

    1984-07-01

    Calculations presented by Bourne contain some order-of-magnitude errors, and give the misleading impression that estimates of fish consumption by seabirds in the North Sea may be as low as 0.25%, or as high as 48%, of fish production, depending on the method of calculation. It is likely that the true figure is closer to 20% once the errors in Bourne's calculations are corrected, but several areas of uncertainty require further study; particularly seabird diets and foraging ranges, fish distribution and movements. Studies from other parts of the world show that seabird numbers can dramatically alter in response to changes in food abundance. Some changes result from natural perturbations and others from effects of overexploitation of fish stocks by man. Effects of overfishing seem likely to be potentially, at least as serious, as effects of oil or chemical pollution in many regions, possibly including the North Sea. 48 references.

  6. The outlook for investment in the Norwegian North Sea

    International Nuclear Information System (INIS)

    Enger, T.

    1992-01-01

    An outline of the investment potential for oil and gas production on the Norwegian continental shelf is given. The continental shelf includes the Haltenbanken area and the Barents Sea as well as the North Sea. A description of existing projects and present knowledge of future prospects is given. The total production of oil and gas in 1990 was 107 million toe, the ratio of oil to gas production being 4:1. The relationship between oil and gas will change dramatically in the future however as the gas share in fields under development is much greater than in currently producing fields. The greatest potential for gas is expected to be in the Barents Sea which, being located at a considerable distance from existing gas markets presents a great challenge for commercial development. The conclusion drawn from the outline is that the present level of investment will be maintained or increase slightly over the next four to five years. For the period up to the turn of the century there is increasing uncertainty over the investment level which will become more and more dependent upon further expansion of gas exports but a best estimate is for continued investment stability beyond the year 2000. The production level can be expected to increase and reach a peak during the late 1990s. The resource base is sufficient to maintain a high production level for several decades after the year 2000. (UK)

  7. Draft Memorandum for the North Sea

    International Nuclear Information System (INIS)

    2008-12-01

    In the National Water Plan it is described which measures must be taken to keep the Netherlands safe and livable for future generations and to make use of the chances offered by water. This memorandum serves as a document by means of which political choices for the North Sea policy, as formulated in the National Water Plan, are made more transparent [nl

  8. Elastic behaviour of North Sea chalk

    DEFF Research Database (Denmark)

    Gommesen, Lars; Fabricius, Ida Lykke; Mukerji, T.

    2007-01-01

    -consistent approximation, which here represents the unrelaxed scenario where the pore spaces of the rock are assumed to be isolated, and the Gassmann theory, which assumes that pore spaces are connected, as tools for predicting the effect of hydrocarbons from the elastic properties of brine-saturated North Sea reservoir...

  9. Satellite observations of oil spills in Bohai Sea

    International Nuclear Information System (INIS)

    Wei, Y L; Tang, Z Y; Li, X F

    2014-01-01

    Several oil spills occurred at two oil platforms in Bohai Sea, China on June 4 and 17, 2011. The oil spills were subsequently imaged by different types of satellite sensors including SAR (Synthetic Aperture Radar), Chinese HJ-1-B CCD and NOAA MODIS. In order to detect the oil spills more accurately, images of the former three sensors were used in this study. Oil spills were detected using the semi-supervised Texture-Classifying Neural Network Algorithm (TCNNA) in SAR images and gradient edge detection algorithm in HJ-1-B and MODIS images. The results show that, on June 11, the area of oil slicks is 31 km 2 and they are observed in the vicinity and to the north of the oilfield in SAR image. The coverage of the oil spill expands dramatically to 244 km 2 due to the newly released oil after June 11 in SAR image of June 14. The results on June 19 show that under a cloud-free condition, CCD and MODIS images capture the oil spills clearly while TCNNA cannot separate them from the background surface, which implies that the optical images play an important role in oil detection besides SAR images

  10. How attractive is the North Sea to the financial community?

    International Nuclear Information System (INIS)

    Arnott, R.

    1992-01-01

    How attractive is the North Sea to the financial community? This question is answered by discussing the type of investment opportunity that the North Sea offers the investor. It is shown how North Sea investments have performed and some of the methods used to measure that performance are discussed. Finally, some thoughts on the future importance of the North Sea to the financial community reach the conclusion that it will remain important for some years to come. (author)

  11. Jurassic domes in the North Sea - northern North Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Surlyk, F. [Univ. of Copenhagen, Geological Inst., Copenhagen (Denmark)

    1996-12-31

    The stratigraphic and tectonic evolution of the Jurassic of East Greenland, the Norwegian Shelf and the North Sea is remarkably similar. A major Middle Jurassic unconformity occurs in all three areas. In the North Sea it is commonly termed the `Mid-Cimmerian Unconformity` and is characterized by progressive truncation of the underlying section towards a centre at the triple junction between the Central Graben, Viking Graben and Moray Firth. Strata above the unconformity show a progressive Late Aalenian-Early Kimmeridgian onlap in the same direction. These relations have been interpreted as caused by Early Jurassic uplift and of a major thermal dome in the central North Sea, followed by Medial and Late Jurassic rifting, erosion, deflation and transgression of the dome. The East Greenland unconformity shows progressive truncation of underlying strata from south to north, and Bajocian to Callovian onlap in the same direction. The same pattern seems to be developed on the conjugate Norwegian margin. This suggests the possibility that the three unconformities have similar causes for their development. It is proposed that major rift domes formed in the Central North Sea and in the Greenland-Norway seaway in Early Jurassic times. The domes were eroded and gradually deflated during Medial Jurassic times and were finally submerged by the Late Oxfordian-Kimmeridgian. They were associated with volcanism and rifting which was delayed with respect to dome initiation. Roughly contemperaneous domes were present west of Britain, north of the Porcupine Seabight, and in Scania, southern Sweden, as reflected by development of asymmetrical unconformities showing progressive truncation of underlying strata, onlap of overlying Jurassic strata, and associated intrusive and extrusive volcanism. The domes are related to impingement of the heads of transient mantle plumes at the base of the lithosphere. The associated unconformities are thus of non-eustatic nature. Domal uplift and

  12. Chemical composition of Pechora Sea crude oil

    Directory of Open Access Journals (Sweden)

    Derkach S. R.

    2017-03-01

    Full Text Available The physicochemical properties of the Pechora Sea shelf oil and its chemical composition have been studied using the methods of refractometry, titrimetry, viscometry, rheometry and standard methods for the analysis of oil and petroleum products. The fractionation of oil is held at atmospheric pressure, some fractions boiling at the temperature below and above 211 °C have been received. Chemical structural-group composition of oil and its components has been investigated using a Fourier infrared (IR spectroscopy method. The density of oil has been obtained, it is equal to 24.2 API. The chemical composition analysis shows that water content in the investigated oil sample is about 0.03 % (by weight. The oil sample contains hydrocarbons (including alkanes, naphthenes, arenes and asphaltenes with resins; their content is equal to 89 and 10 % (by weight respectively. Alkane content is about 66 %, including alkanes of normal structure – about 37 %. The solidification temperature of oil sample is equal to –43 °C. This low temperature testifies obliquely low content of solid alkanes (paraffin. Bearing in mind the content of asphaltenes with resins we can refer the investigated oil sample to resinous oils. On the other hand spectral coefficient values (aromaticity quotient and aliphaticity quotient show that oil sample belongs to naphthenic oils. According to the data of Fourier IR spectroscopy contents of naphthenes and arenes are 5.9 and 17.8 % respectively. Thus, the obtained data of chemical structural-group composition of crude oil and its fractions indicate that this oil belongs to the heavy resinous naphthenic oils. The rheological parameters obtained at the shear deformation conditions characterize the crude oil as a visco-plastic medium.

  13. Hydrogeochemical modelling of fluid–rock interactions triggered by seawater injection into oil reservoirs: Case study Miller field (UK North Sea)

    International Nuclear Information System (INIS)

    Fu, Yunjiao; Berk, Wolfgang van; Schulz, Hans-Martin

    2012-01-01

    A hydrogeochemical model is presented and applied to quantitatively elucidate interdependent reactions among minerals and formation water–seawater mixtures at elevated levels of CO 2 partial pressure. These hydrogeochemical reactions (including scale formation) occur within reservoir aquifers and wells and are driven by seawater injection. The model relies on chemical equilibrium thermodynamics and reproduces the compositional development of the produced water (formation water–seawater mixtures) of the Miller field, UK North Sea. This composition of the produced water deviates from its calculated composition, which could result solely from mixing of both the end members (formation water and seawater). This indicates the effect of hydrogeochemical reactions leading to the formation and/or the dissolution of mineral phases. A fairly good match between the modelled and measured chemical composition of produced water indicates that hydrogeochemical interactions achieve near-equilibrium conditions within the residence time of formation water–seawater mixtures at reservoir conditions. Hence the model enables identification of minerals (including scale minerals), to quantitatively reproduce and to predict their dissolution and/or formation. The modelling results indicate that admixing of seawater into formation water triggers the precipitation of Sr–Barite solid solution, CaSO 4 phases and dolomite. In contrast, calcite and microcrystalline quartz are dissolved along the seawater flow path from the injection well towards the production well. Depending on the fraction of seawater admixed, interdependent reactions induce profound modifications to the aquifer mineral phase assemblage. At low levels of seawater admixture, Ba–Sr sulfate solid solution is precipitated and coupled to concurrent dissolution of calcite and microcrystalline quartz. Massive dissolution of calcite and the formation of CaSO 4 phases and dolomite are triggered by intense seawater admixture

  14. Responding to the Sea Empress oil spill

    International Nuclear Information System (INIS)

    Leonard, D.R.P.; Law, R.J.; Kelly, C.A.

    1999-01-01

    The Ministry of Agriculture, Fisheries and Food (MAFF) is a government department which has responsibility in England and in Wales (acting on behalf of the Secretary of State for Wales) for controlling deposits in the sea, including approving the use of dispersants in oil spill response. MAFF also has responsibility in relation to the management of sustainable commercial fish and shellfish fisheries. Following the grounding of the tanker Sea Empress on 15 February 1996, over 72,000 tonnes of crude oil and bunker fuel was lost. This paper summarises the involvement of MAFF staff in the response phase, and in the subsequent assessment of the environmental impact of the oil spill and the associated clean up operations on commercial fisheries. After two and a half years of environmental monitoring and complementary research, it is concluded that the oil spill has had an insignificant impact on these fisheries beyond their closure during the incident response phase. Suggestions for further work are discussed. (author)

  15. Shallow gas in Cenozoic sediments of the Southern North Sea

    Science.gov (United States)

    Trampe, Anna F.; Lutz, Rüdiger; Franke, Dieter; Thöle, Hauke; Arfai, Jashar

    2013-04-01

    Shallow petroleum systems in the southern North Sea are known for several decades but they were not actively explored for a long time. In recent years these unconventional shallow petroleum systems are studied in greater detail and one shallow gas field (A-12) is in production in the Netherlands. Additionally, oil was encountered in Miocene sandstones in the southern Danish North Sea (Lille John well) just north of the Danish-German border. Seismic amplitude anomalies are an indication for hydrocarbons in sediments. Therefore we have mapped the occurrence of seismic amplitude anomalies in the German North Sea based on more than 25.000 km of 2D seismic data and around 4.000 km2 of 3D seismic data. Amplitude anomalies are ubiquitous phenomena in the study area. These anomalies are not only caused by hydrocarbons but also by changing lithologies e.g. peat or fluid migration. Therefore several classes of seismic anomalies, e.g. bright spots, chimneys, blanking areas and velocity pull-down were mapped. Examples for these classes were studied with AVO (amplitude variation with offset) analyses to verify the existence or non-existence of gas in the sediments. Shallow gas can be produced and transported through the dense pipeline grid of the southern and central North Sea or it could be burned offshore close to wind parks in small power plants and the electric energy then transported through the existing power connections of the wind parks. Thus enabling a continuous energy supply during calm wind periods. This study is carried out within the framework of the project "Geoscientific Potential of the German North Sea (GPDN)" in which the Cenozoic sedimentary system was mapped in great detail. A detailed model of delta evolution (Baltic river system) was developed which serves as a structural framework. The studied interval is time equivalent to the Utsira formation which is used offshore Norway for sequestration of CO2. These different possibilities of using or exploiting

  16. The North Cape oil spill assessment: PAHs in oil

    International Nuclear Information System (INIS)

    Brown, J.; Boehm, P. D.; Hardestine, J. H.; Douglas, G. S.

    1997-01-01

    The North Cape oil spill in January 1996 resulted in the release of an estimated 827,000 gallons of No. 2 home heating oil into the nearshore turbulent waters of coastal Rhode Island. The oil was mixed into the water column and was transported on the surface as well as below the surface. Some of the spilled oil entered the coastal ponds behind the beaches. Sampling and chemical analysis for detailed suites of petroleum saturated and polycyclic aromatic hydrocarbons (PAHs) was undertaken as part of the assessment of the fate of the oil spill and of the exposure to the marine environment. The ponds were found to contain significant quantities of background petroleum hydrocarbons, including petrogenic PAHs and combustion PAHs. Initial assessment pointed (incorrectly as it turned out) to widespread contamination due only to the North Cape spill. Application of advanced chemical fingerprinting approaches, and geochemical biomarker data illustrated that many of the PAHs consisted of combustion-related 4- and 5-ringed PAHs, attributable to diesel fuel used routinely by boats in the area. The analysis demonstrated that the use of non-specific total PAH data and insufficient fingerprinting and allocation of petrogenic residues has the potential to overestimate contamination and hence injury to the environment in similar oil spill situations

  17. Pseudocollapse and rebuilding of North Sea mackerel (Scomber scombrus)

    DEFF Research Database (Denmark)

    Jansen, Teunis

    2014-01-01

    The largest observed change in mackerel (Scomber scombrus) abundance in the North Atlantic happened when the so-called “North Sea mackerel” collapsed due to overfishing. Despite protection, it has remained in a depleted state. Central to this interpretation was that the “North Sea mackerel...

  18. Oil pollution in the Baltic Sea

    International Nuclear Information System (INIS)

    Kostianoy, Andrey G.; Lavrova, Olga Yu.

    2014-01-01

    This thorough review is based on observational satellite, airborne and in-situ data, scientific literature and technical reports, as well as the substantial experience of the authors, who hail from several Baltic Sea countries. They pay special attention to national practices, HELCOM and EMSA CleanSeaNet activities in oil pollution monitoring, and show different applications of the Seatrack Web model for oil spill drift prediction and the identification of illegal polluters, as well as for environmental risk assessment. Furthermore, some of the results on satellite monitoring of the Nord Stream gas pipeline construction in the Gulf of Finland are presented. This volume addresses the needs of specialists working in different fields of marine, environmental, and remote sensing sciences. It is a useful handbook on oil pollution for international and governmental agencies, as well as for policy makers who plan and manage oil and gas projects, the construction of ports and terminals, shipping, fishery, recreation, and tourist activities in the Baltic Sea.

  19. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  20. Oil spill preparedness in the Mediterranean Sea

    International Nuclear Information System (INIS)

    Jorigne, E.M.; Wong, K.V.

    1993-01-01

    Over 15% of the world's consumption of crude oil and refined products is shipped through the Mediterranean Sea each year. The sea is one of the most polluted areas in the world and has areas of high risk for oil spills, notably those places where there is a very narrow passage between coasts or islands. The region also needs to modernize its ports by developing more deballasting facilities, since a large percentage of spill accidents happens during terminal operations. Release of oily wastes from ships is also significant. The World Bank Global Environment Facility trust fund is working on a project to help the southwest Mediterranean countries modernize reception facilities for ballast water, bilge water, and oily waste water. The Regional Marine Pollution Emergency Response Center (REMPEC) in Malta acts as the coordinating center for regional contingency planning for oil spill response. The cost of the port facilities modernization program and oil spill contingency plan implementation for the Mediterranean is estimated at US$444 million. An allocation of costs is suggested which will help those countries needing more financial aid to implement the proposed programs. In the long run, the cost of these programs will be much lower than that of a massive oil spill cleanup. 7 refs., 2 figs., 4 tabs

  1. Management and control of microbiologically influenced corrosion (MIC) in the oil and gas industry - Overview and a North Sea case study

    DEFF Research Database (Denmark)

    Skovhus, Torben Lund; Eckert, Richard B; Rodrigues, Edgar

    2017-01-01

    the oil and gas industry has seen regarding MIC research over the past decade. The paper starts out with an overview of where in the process stream MIC occurs - from the oil reservoir to the consumer. Both biotic and abiotic corrosion mechanisms are explained in the context of managing MIC using...... to manage the corrosion threat, operators commonly use models to support decision making. The models use qualitative, semi-quantitative or quantitative measures to help assess the rate of degradation caused by MIC. The paper reviews four existing models for MIC Threat Assessment and describe a new model...

  2. North Sea focus on radwaste disposal

    International Nuclear Information System (INIS)

    Cope, D.

    1990-01-01

    At the recent North Sea Conference in the Netherlands possible future strategies for managing radioactive waste (radwaste) proved to be a contentious issue. Several of its North Sea littoral neighbours sought a categorical assurance that the UK would forego the option of constructing a subterranean radwaste repository which though accessed from land, extends under the coastline, or a sub-seabed facility reached from an offshore structure. It was pointed out that the UK has no present plans for such a radwaste repository. However, sub-seabed designs as a possibility for future repositories were not ruled out. NIREX has decided to concentrate its exploration work at two sites -Sellafield and Dounreay. Both sites are coastal locations and the government is aware that detailed geological exploration may favour extension of a radwaste repository beyond the shoreline, even if initially developed entirely on land. The design of such a radioactive waste repository is outlined. The position of NIREX and the Radioactive Waste Management Advisory Committee is discussed. (author)

  3. Change of Static and Dynamic Elastic Properties due to CO² Injection in North Sea Chalk

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Hjuler, M.L.; Christensen, H.F.

    2012-01-01

    important in enhanced oil recovery by CO2 injection (CO2-EOR) in chalk as, chalk reservoirs are vulnerable to compaction under changed stress and pore fluid. From South Arne field, North Sea, we used Ekofisk Formation chalk having approximately 20% non-carbonate and Tor Formation chalk having less than 5...

  4. Islands of steel rise over North Sea gas. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Hind, J A

    1965-10-27

    Nowhere is the offshore oil and gas prospecting boom more enthusiastic, urgent, and crowded than in the North Sea. The type of rig required for this type of offshore drilling mainly depends upon how far offshore drilling is to take place. The fixed jack-up type is most suitable where depth of water is not excessive and for actual drilling operations were the drill is most easily held steady over the hole. This type of rig presents a stability problem under tow from location to location with a shallow depth of hull. Depth of water limits the operational mobility of the submerged-type rig and it is the most prone to scouring effects. Fully floating and ship-mounted rigs solve the depth of water problem and many others associated with ocean transportation. However, this is at the expense of more difficult drilling operations and complexity of equipment. Semi-submersibles are a popular compromise between fixed sit-on-bottom rigs and fully floating types. From a naval architectural point of view they have much to recommend them as all- round units. Typical North Sea drill rigs are described and a table is given for complete details.

  5. Scientific symposium on the North Sea quality status report 1993

    International Nuclear Information System (INIS)

    Andersen, J.; Karup, H.; Nielsen, U.B.

    1996-01-01

    The Scientific Symposium on the 1993 North Sea quality Status Report took place in Ebeltoft, Denmark from 18 to 21 April 1994. The aim was to bring together scientists, researchers and administrators from governments, industries and environmental organizations from the countries around the North Sea in order to review new information which may supplements the 1993 North Sea Quality Status Report and to discuss the Quality Status Report and its possible implications. The 1993 North Sea Quality Status Report has been prepared by the North Sea Task force as a comprehensive statement of circulation patterns, inputs and dispersion of contaminants, ecological conditions and effects of human activities in the North Sea including the Skagerrak and the Kattegat. The programme of the Scientific Symposium on the 1993 North Sea Quality Status Report included 8 sessions for oral presentations, a poster session presenting the North Sea Task Force subregional reports and a poster session presenting individual posters. The headings of the sessions were as follows: Oceanography, Models and Remote Sensing; Ecosystem Structure; Contaminants -Distribution and Effects; Nutrients and Eutrophication Problems; Effects of Fishery; Habitats and Species; Management Implications; Conclusions and Recommendations. The proceedings includes a total of 45 contributed papers. (EG)

  6. Cleaning up the sea bed in the North Sea. 1994

    International Nuclear Information System (INIS)

    1995-01-01

    The yearly raid was executed in an efficient way and without excess technical equipment interruptions. The vessel ''Lance'' owned by the Norwegian Sea Mapping Authorities which was used for the sonar mapping of the sea bed, was equipped with a Klein 531T side seeking sonar, a Simrad echo sounder of the type EM100 (multiray) and differential GPS navigation system. The executive committee has earlier expressed desire for a strengthening of the co-operation with the Norwegian Sea Mapping Authorities. The use of the vessel was in accordance with this wish. Stolt Comex Seaway A/S used the vessel M/S ''Seaway Commander'' and the underwater vessel ''Solo'' for the cleaning up project. The systems worked satisfactory during the entire operation. The cleaning operation was in 1994 carried out in 2 sections. The Petroleum Directorate agreed to letting the M/S ''Seaway Commander'' complete the project for Norsk Hydro at the Troll field in order to avoid delays in the Troll Oil project. In both periods there were good weather conditions. There was no extensive discontinuations due to the weather. During the two periods of 13,5 days 259 out of 370 positions were investigated visually through the systems. This is in average about 20 inspected positions a day. The reason for the high average is that the sailing distances are short between the positions and the findings corresponded to stated positions and sonar interpretations. Also this year there was installed a side seeking sonar in the underwater vessel which resulted in reduced investigation time at each aim. It was possible with this type of sonar to identify the goal quicker and to seek during transit between goals at moderate distances. Few articles with certainty contributed by the petroleum activities were retrieved

  7. Submarine pipelines and the North Sea environment

    International Nuclear Information System (INIS)

    Haldane, D.; Paul, M.A.; Reuben, R.L.; Side, J.C.

    1992-01-01

    The function and design of pipelines for use on the United Kingdom continental shelf are described. Environmental influences which can threaten the integrity of seabed pipelines in the North Sea include hydrodynamic forces due to residual, tidal and wave currents, the nature of seabed sediments and corrosion by seawater. Damage may be caused to pipelines by interaction with vessel anchors and with fishing gear. Special care has to be taken over the selection of the general area for the landfall of a pipeline and the engineering of the installation where the pipeline comes ashore. Trenching and other protection techniques for pipelines are discussed together with hydrostatic testing and commissioning and subsequent inspection, maintenance and repair. (UK)

  8. Deposition of nitrogen into the North Sea

    DEFF Research Database (Denmark)

    Leeuw, G. de; Skjøth, C.A.; Hertel, O.

    2003-01-01

    The flux of nitrogen species from the atmosphere into the ocean, with emphasis on coastal waters, was addressed during the ANICE project (Atmospheric Nitrogen Inputs into the Coastal Ecosystem). ANICE focused on quantifying the deposition of atmospheric inputs of inorganic nitrogen compounds (HNO3...... and Harwich/Newcastle. These measurements provided data for sensitivity studies of a variety of problems associated with the coastal region that are not easily evaluated with larger scale models, to constrain models and to test model results. Concentrations of nitrogen compounds over the North Sea...... on experimental results and small-scale model studies. In particular, effects of the aerosol size distribution on the nitrogen deposition are discussed. (C) 2003 Elsevier Ltd. All rights reserved....

  9. Enrichment of Fusobacteria in Sea Surface Oil Slicks from the Deepwater Horizon Oil Spill

    OpenAIRE

    Gutierrez, Tony; Berry, David; Teske, Andreas; Aitken, Michael D.

    2016-01-01

    The Deepwater Horizon (DWH) oil spill led to rapid microbial community shifts in the Gulf of Mexico, including the formation of unprecedented quantities of marine oil snow (MOS) and of a massive subsurface oil plume. The major taxa that bloomed in sea surface oil slicks during the spill included Cycloclasticus, and to a lesser extent Halomonas, Alteromonas, and Pseudoalteromonas?organisms that grow and degrade oil hydrocarbons aerobically. Here, we show that sea surface oil slicks at DWH cont...

  10. Influence of oil pollution to the total biological productivity of the Caspian sea

    International Nuclear Information System (INIS)

    Salmanov, M.A.

    2005-01-01

    Full text : As a result of a numerous researches it was defined that among all the species of pollutants polluting water reservoirs, oil and its components has a leading role. In this respect the Caspian Sea is in a special condition, as it exists as an isolated water reservoirs it had a direct relation with oil and oil products earlier than others and more than the rest. For this reason the oil in the Caspian Sea in its turn has become a permanent substrate. The main reservoirs of contamination of environmental medium of the Caspian Sea by oil and oil products are oil industries, oil pipelines, oil processing ventures, oil transportation, oil-gas service and oil drilling. At the same time oil components due to dried lands appear in the sea by river floods that are a heavy showers. Oil is a complex environmental compound of carbohydrogenes and distributed in environmental medium. Its characteristic that no other pollutant as dangerous it hasn't been and cannot be compared with oil according to the range of distribution, amount of pollutant resources and range of pressure to all the compounds of environmental medium. During the involvement of oil in the hydrosphere deep, often inattentive changes of its chemical, physiological and microbiological features and even reconstruction of all the hydrospheric profile take place. Being dynamic and mobile it penetrates toxic metals increasing their emigrational ability, subsides to the bottom and oppresses benthofauna. At the same time oil products in water reservoirs in common negatively influence to the balance of oxygen and position of biocenoses in the surface layers of sea water. In the given information the results of many years and monitoring character of researches about the influence of pollution in the base of total biological productivity of the Caspian Sea are presented (as well as oil pollution). It was defined that in the basins of the North (Makachkala - from Berbash, Bautina, Shevchenko fleet), Middle (Sand

  11. Why is the North Sea West of Us?

    DEFF Research Database (Denmark)

    Gammeltoft, Peder

    2016-01-01

    . Occurrences of sea names such as the North Sea are examined and analysed to see how they spread from an original one-language form to exist in multiple languages, and analyses them from a linguistic, geographic and nautical perspective. It is found that Seas or bodies of water in stretches of sea are named......This article focuses on the motivations behind sea-naming, by means of examples from Europe but also elsewhere. Why do certain sea names become dominant while others retract into local forms or simply die out? The article takes us back in time to the early days of map-making and, indeed, earlier...

  12. Ecology and conservation of North American sea ducks

    Science.gov (United States)

    Savard, Jean-Pierre L.; Derksen, Dirk V.; Esler, Daniel N.; Eadie, John M.

    2015-01-01

    The past decade has seen a huge increase in the interest and attention directed toward sea ducks, the Mergini tribe. This has been inspired, in large part, by the conservation concerns associated with numerical declines in several sea duck species and populations, as well as a growing appreciation for their interesting ecological attributes. Reflecting the considerable research recently conducted on this tribe, Ecology and Conservation of North American Sea Ducks examines the 15 extant species of sea ducks from North America.

  13. Occurrence, effects, and fate of oil polluting the sea

    Energy Technology Data Exchange (ETDEWEB)

    ZoBell, C E

    1963-01-01

    A major source of oil polluting the sea is ships which use their cargo or fuel tanks alternately for carrying different kinds of oil and salt water ballast. Wash waters, wrecks, bilge water, and accidental spills account for large volumes of oils being discharged into the sea. Recreational beaches and sea birds are most adversely affected by oil pollution. Oysters and other shellfish in certain beds are injured by oil. Only at its worst does oil pollution appear to be injurious to animal and plant life in the sea. The movement, modification, and persistence of oil in the sea or on its shores are influenced by the properties of the oil, its dispersion in water, ocean currents, wind, sunlight, and many other factors. Most beached oils and tars become mixed with or smeared on solids to be buried, decomposed, or carried back into the sea by the tidal currents and the backwash of waves. Virtually all kinds of oils are susceptible to microbial oxidation, which is most rapid at temperatures ranging from 15 to 35 degrees C. In the marine environment oil persists only when protected from bacterial action. 78 references, 5 figures, 2 tables.

  14. Histopathologic lesions in sea otters exposed to crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Lipscomb, T.P.; Harris, R.K.; Moeller, R.B.; Pletcher, J.M.; Haebler, R.J.; Ballachey, B.E. (Armed Forces Institute of Pathology, Washington, DC (United States))

    1993-01-01

    Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters (Enhydra lutris) that appeared to be contaminated with oil, that were in danger of becoming contaminated, or that were behaving abnormally were captured and taken to rehabilitation centers. Exposure to oil was assessed by visual examination when otters arrived at the centers. Degree of oil exposure was graded according to the following criteria: oil covering greater than 60% of the body--heavily contaminated; oil covering 30-60% of the body--moderately contaminated; oil covering less than 30% of the body or light sheen on fur--lightly contaminated. If there was no oil visible, otters were considered uncontaminated. Tissues from 51 oil-contaminated sea otters (14 males, 37 females) and from six uncontaminated sea otters (three males, three females) that died in rehabilitation centers were examined histologically. Among oil-contaminated sea otters, 19/46 had interstitial pulmonary emphysema, 13/40 had gastric erosion and hemorrhage, 11/47 had centrilobular hepatic necrosis, 14/47 had periportal to diffuse hepatic lipidosis, and 10/42 had renal tubular lipidosis. Of the uncontaminated sea otters, 1/6 had gastric erosion and hemorrhage and 1/6 had diffuse hepatic lipidosis. Histologic examinations were performed on tissues from five sea otters found dead with external oil present 15 to 16 days after the spill. Periportal hepatic lipidosis and renal tubular lipidosis were found in 3/5, and interstitial pulmonary emphysema was found in 1/5. Tissues from six apparently normal sea otters collected from an area not affected by an oil spill were examined histologically, and none of these lesions were found. We conclude that interstitial pulmonary emphysema, centrilobular hepatic necrosis, and hepatic and renal lipidosis of sea otters were associated with exposure to crude oil. Gastric erosion and hemorrhage may have been associated with stress of captivity and/or oil exposure.

  15. Histopathologic lesions in sea otters exposed to crude oil

    Science.gov (United States)

    Lipscomb, T.P.; Harris, R.K.; Moeller, R.B.; Pletcher, J.M.; Haebler, R.J.; Ballachey, Brenda E.

    1993-01-01

    Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters (Enhydra lutris) that appeared to be contaminated with oil, that were in danger of becoming contaminated, or that were behaving abnormally were captured and taken to rehabilitation centers. Exposure to oil was assessed by visual examination when otters arrived at the centers. Degree of oil exposure was graded according to the following criteria: oil covering greater than 60% of the body - heavily contaminated; oil covering 30–60% of the body - moderately contaminated; oil covering less than 30% of the body or light sheen on fur - lightly contaminated. If there was no oil visible, otters were considered uncontaminated. Tissues from 51 oil-contaminated sea otters (14 males, 37 females) and from six uncontaminated sea otters (three males, three females) that died in rehabilitation centers were examined histologically. Among oil-contaminated sea otters, 19/46 had interstitial pulmonary emphysema, 13/40 had gastric erosion and hemorrhage, 11/47 had centrilobular hepatic necrosis, 14/47 had periportal to diffuse hepatic lipidosis, and 10/42 had renal tubular lipidosis. Of the uncontaminated sea otters, 1/6 had gastric erosion and hemorrhage and 1/6 had diffuse hepatic lipidosis. Histologic examinations were performed on tissues from five sea otters (three males, two females) found dead with external oil present 15 to 16 days after the spill. Periportal hepatic lipidosis and renal tubular lipidosis were found in 3/5, and interstitial pulmonary emphysema was found in 1/5. Tissues from six apparently normal sea otters (four males, two females) collected from an area not affected by an oil spill were examined histologically, and none of these lesions were found. We conclude that interstitial pulmonary emphysema, centrilobular hepatic necrosis, and hepatic and renal lipidosis of sea otters were associated with exposure to crude oil. Gastric erosion and hemorrhage may have been associated with

  16. Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian Sea and White Sea from R/Vs Artemovsk, Atlantida, Okeanograf, Professor Rudovits, and ice observations, 1957 - 1995 (NODC Accession 0073674)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, Salinity, Oxygen, Phosphate, pH and Alkalinity data collected in the North Atlantic Ocean, Baltic Sea, Barents Sea, Greenland Sea, North Sea, Norwegian...

  17. North Sea ecosystem change from swimming crabs to seagulls.

    Science.gov (United States)

    Luczak, C; Beaugrand, G; Lindley, J A; Dewarumez, J-M; Dubois, P J; Kirby, R R

    2012-10-23

    A recent increase in sea temperature has established a new ecosystem dynamic regime in the North Sea. Climate-induced changes in decapods have played an important role. Here, we reveal a coincident increase in the abundance of swimming crabs and lesser black-backed gull colonies in the North Sea, both in time and in space. Swimming crabs are an important food source for lesser black-backed gulls during the breeding season. Inhabiting the land, but feeding mainly at sea, lesser black-backed gulls provide a link between marine and terrestrial ecosystems, since the bottom-up influence of allochthonous nutrient input from seabirds to coastal soils can structure the terrestrial food web. We, therefore, suggest that climate-driven changes in trophic interactions in the marine food web may also have ensuing ramifications for the coastal ecology of the North Sea.

  18. Alaskan North Slope Oil & Gas Transportation Support

    Energy Technology Data Exchange (ETDEWEB)

    Lilly, Michael Russell [Geo-Watersheds Scientific LLC, Fairbanks, AK (United States)

    2017-03-31

    North Slope oil and gas resources are a critical part of US energy supplies and their development is facing a period of new growth to meet increasing national energy needs. While this growth is taking place in areas active in development for more than 20 years, there are many increasing environmental challenges facing industry and management agencies. A majority of all exploration and development activities, pipeline maintenance and other field support activities take place in the middle of winter, when the fragile tundra surface is more stable. The window for the critical oil and gas winter operational season has been steadily decreasing over the last 25 years. The number of companies working on the North Slope is increasing. Many of these companies are smaller and working with fewer resources than the current major companies. The winter operations season starts with the tundra-travel opening, which requires 15 cm of snow on the land surface in the coastal management areas and 23 cm in the foothills management areas. All state managed areas require -5°C soil temperatures at a soil depth of 30 cm. Currently there are no methods to forecast this opening date, so field mobilization efforts are dependent on agency personnel visiting field sites to measure snow and soil temperature conditions. Weeks can be easily lost in the winter operating season due to delays in field verification of tundra conditions and the resulting mobilization. After the season is open, a significant percentage of exploration, construction, and maintenance do not proceed until ice roads and pads can be built. This effort is dependent on access to lake ice and under-ice water. Ice chipping is a common ice-road construction technique used to build faster and stronger ice roads. Seasonal variability in water availability and permitting approaches are a constant constraint to industry. At the end of the winter season, projects reliant on ice-road networks are often faced with ending operations

  19. Sea turtles sightings in North Carolina

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea turtles sightings are reported to the NMFS Beaufort Laboratory sea turtle program by the general public as they are fishing, boating, etc. These sightings...

  20. Space weather effects on drilling accuracy in the North Sea

    Directory of Open Access Journals (Sweden)

    S. J. Reay

    2005-11-01

    Full Text Available The oil industry uses geomagnetic field information to aid directional drilling operations when drilling for oil and gas offshore. These operations involve continuous monitoring of the azimuth and inclination of the well path to ensure the target is reached and, for safety reasons, to avoid collisions with existing wells. Although the most accurate method of achieving this is through a gyroscopic survey, this can be time consuming and expensive. An alternative method is a magnetic survey, where measurements while drilling (MWD are made along the well by magnetometers housed in a tool within the drill string. These MWD magnetic surveys require estimates of the Earth's magnetic field at the drilling location to correct the downhole magnetometer readings. The most accurate corrections are obtained if all sources of the Earth's magnetic field are considered. Estimates of the main field generated in the core and the local crustal field can be obtained using mathematical models derived from suitable data sets. In order to quantify the external field, an analysis of UK observatory data from 1983 to 2004 has been carried out. By accounting for the external field, the directional error associated with estimated field values at a mid-latitude oil well (55° N in the North Sea is shown to be reduced by the order of 20%. This improvement varies with latitude, local time, season and phase of the geomagnetic activity cycle. By accounting for all sources of the field, using a technique called Interpolation In-Field Referencing (IIFR, directional drillers have access to data from a "virtual" magnetic observatory at the drill site. This leads to an error reduction in positional accuracy that is close to matching that of the gyroscopic survey method and provides a valuable independent technique for quality control purposes.

  1. Compositional Analysis of North Sea Oils

    DEFF Research Database (Denmark)

    Dandekar, Abhijit; Andersen, Simon Ivar; Stenby, Erling Halfdan

    2000-01-01

    The molar fluid composition of either the reservoir fluid or the well stream is determined by combining the true boiling point (TBP) distillation data with gas chromatographic (GC) analysis of the light ends. For the purpose of thermodynamic simulation of phase behavior of petroleum reservoir...... fluids, in addition to the compositional data, physical properties of the pseudo fractions, i.e. density and molecular weight are required. A major drawback of the TBP distillation is the fact that the fractions contain typically 20 - 30% of the material outside the defined boiling range. Another...

  2. Microbial biogeography of the North Sea during summer

    NARCIS (Netherlands)

    Brandsma, J.; Martínez Martínez, J.; Slagter, H.A.; Evans, C.; Brussaard, C.P.D.

    2013-01-01

    Micro-organisms are vital for the functioning of all food webs and are the major drivers of the global biogeochemical cycles. The microbial community compositions and physicochemical conditions of the different water masses in the North Sea, a biologically productive sea on the northwestern European

  3. Acute health effects of the Sea Empress oil spill.

    Science.gov (United States)

    Lyons, R A; Temple, J M; Evans, D; Fone, D L; Palmer, S R

    1999-05-01

    To investigate whether residents in the vicinity of the Sea Empress tanker spill suffered an increase in self reported physical and psychological symptoms, which might be attributable to exposure to crude oil. Retrospective cohort study; postal questionnaire including demographic details, a symptom checklist, beliefs about health effects of oil and the Hospital Anxiety and Depression and SF-36 mental health scales. Populations living in four coastal towns on the exposed south Pembrokeshire coast and two control towns on the unexposed north coast. 539 exposed and 550 unexposed people sampled at random from the family health services authority age-sex register who completed questionnaires. Adjusted odds ratios for self reported physical symptoms; scores on the Hospital Anxiety and Depression and SF-36 mental health scales, in 1089 people who responded out of a possible 1585 (69%). Living in areas exposed to the crude oil spillage was significantly associated with higher anxiety and depression scores, worse mental health; and self reported headache (odds ratio = 2.35, 95% CI 1.56, 3.55), sore eyes (odds ratio = 1.96, 95% CI 1.06, 3.62), and sore throat (odds ratio = 1.70, 95% CI 1.12, 2.60) after adjusting for age, sex, smoking status, anxiety, and the belief that oil had affected health. People living in exposed areas reported higher rates of physical and psychological symptoms than control areas. Symptoms significantly associated with exposure after adjustment for anxiety and health beliefs were those expected from the known toxicological effect of oil, suggesting a direct health effect on the exposed population.

  4. The North sea, one of the group's anchorage points

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The North Sea is one of the pillars of the Elf Aquitaine group's Exploration-Production strategy. The most recent start-up in the North Sea, last february, concerned the Froy field where Elf Petroleum Norge (AS) is an operator with a 24.573 % interest alongside Statoil, Total Norge AS (15.2346 %) and Norsk Hydro. The first gas sales occurred on June 15, as scheduled. The oil production marketed by Elf (net of royalties) remained stable at 13.9 Gm 3 . At january 1,1995, Elf Aquitaine's mining area covered a gross surface area of 435,894 km 2 . In countries where the group is already established, the policy is : - to withdraw from exploration licenses considered as being the least promising in terms of discovery or profitability; - to concentrate on sectors where the existing production means allow for an optimisation of later developments ; - to penetrate more extensive exploration areas with good targets. In the British zone, the additional reserves revealed in the Elgin and Franklin condensate fields have doubled the initial forecast, placing the former among the major fields. All the discoveries made in the British zone have allowed the group to renew productions until now. Elf's production in Piper, Saltire, Chanter is 100,000 b/d which is added to the production of the Claymore and Scapa fields (100,000 b/d). The Flotta terminal processes the crude coming from these fields to which is added the production from the neighbouring fields of Tartan (Texaco) and Ivanhoe-Rob Roy (Amerada Hess), i.e. a total of more than 300,000 b/d. Other than Elgin or the Viking Graben, the future of the Elf group in Great Britain will most certainly come from the West Shetlands and the Irish Sea. In the Norwegian zone, the group has interest in the Frigg, Heimldal, Ekofisk, Valhall, Lille-Frigg, Froy, Oseberg, Hod, Sleipner East an Sleipner West Brage, Troll, Snorre, Statfjord East and Tordis production fields. (authors). 3 tabs., 1 photo

  5. Oil pollution of the sea – global and regional aspects

    Directory of Open Access Journals (Sweden)

    Marek Begányi

    2006-10-01

    Full Text Available Transport of oil is very important for the world economic and industry. Oil is transported to the countries and states, where it is transformed for the industry. The oil transport is connected with some advantages and disadvantages. One of the disadvantages is the pollution of seas. The pollution is very dangerous for everything and everyone. Transport companies of oil must stop the pollution with new, safety and effective transport technologies.

  6. The importance of North Sea gas to European energy supply

    International Nuclear Information System (INIS)

    Probert, R.

    1992-01-01

    Natural gas can, of course, be transported over very long distances but, because of the economics of gas transmission, its impact is most often local. This has certainly been the case with North Sea gas, which has clearly contributed significantly to European energy supply and will continue to do so for some time to come. The historical importance of the discovery of gas in the North Sea has been that it has enabled natural gas industries to grow rapidly in North West Europe. Without North Sea gas and Dutch gas it is difficult to see how town gas would have been replaced in North West Europe. Certainly, a much smaller natural gas industry would have emerged. North Sea gas has inevitably had the greatest impact on gas markets in the countries of the European Community and this will remain the case in future. Nevertheless, it is inevitable that gas will, in future, flow across more national boundaries than in the past, and that North Sea gas will have an important part to play in meeting the Central European demand for competitively priced, secure supplies. This paper discusses the United Kingdom market for gas and future demand both in the United Kingdom and more widely in Europe. An examination of the availability of gas supplies from the North Sea suggests that it is unlikely that there will be a surplus of gas for export from the United Kingdom continental shelf. Norway will remain the main source of exports, with the Netherlands also in a strong position. Transportation and political aspects are also considered. (author)

  7. The new players - what's happening?[Talisman's petroleum activity in the North Sea]; De nye aktoerene - hva skjer?

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Baard

    2005-03-15

    The oil company Talisman Energy and its activities in the North Sea are presented. The global corporation's strategy is briefly outlined, and this includes focus on upstream activities, area and product mix, having operator responsibility and exploration activities. North America and the North Sea represent 69 percent of the company's reserves and 76 percent of the production. the North Sea challenges for the future are among others the Norwegian fiscal system which does not stimulate marginal activities, leading to a lower level of activity, less focus on cost, premature removal of offshore infrastructure and fewer discoveries of new reserves (ml)

  8. Sea Surface Temperature (14 KM North America)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Product shows local sea surface temperatures (degrees C). It is a composite gridded-image derived from 8-km resolution SST Observations. It is generated every 48...

  9. Situation in the sea area between the North Sea and the Baltic Sea. Situationen i havsomraadet mellan Nordsjoen och Oestersjoen

    Energy Technology Data Exchange (ETDEWEB)

    Dybern, B.I.; Soederstroem, J.; Thorell, L.

    1984-01-01

    Due to the special topographical and hydrological features the seas surrounding Sweden are very sensitive to both natural changes and changes caused by man. The sea area between the North Sea and the Baltic Sea has come into focus during the last few decades due to problems with pollution and its impact on the ecosystems and to overfishing of some commer- cially important species. In order to elucidate the present situation from the Swedish viewpoint, the National Board of Fisheries, the National Environment Protection Board and the County Council of the County Goeteborg and Bohyslaen arranged a Symposium on the Situation in the Sea Area between the North Sea and the Baltic Sea in Goeteborg, 14-16 March, 1983. This volume contains lectures given at that Symposium. In most cases there are English summaries and English translations of texts to figures and tables.

  10. Regulating Offshore Energy Sources in the North Sea : Reinventing the Wheel or a Need for More Coordination?

    NARCIS (Netherlands)

    Müller, Hannah Katharina; Roggenkamp, Martha M.

    In this article we examine the legal frameworks for developing oil, gas and wind energy in the North Sea. We discuss whether there are parallels to be seen and lessons to be learned from these different sectors and suggest that experience in the offshore petroleum sector could be used to improve the

  11. Dynamic and static elastic moduli of North Sea and deep sea chalk

    DEFF Research Database (Denmark)

    Gommesen, Lars; Fabricius, Ida Lykke

    2001-01-01

    We have established an empirical relationship between the dynamic and the static mechanical properties of North Sea and deep sea chalk for a large porosity interval with respect to porosity, effective stress history and textural composition. The chalk investigated is from the Tor and Hod Formatio...

  12. Mechanisms controlling the air–sea CO2 flux in the North Sea

    NARCIS (Netherlands)

    Prowe, A.E.F.; Thomas, Helmuth; Pätsch, Johannes; Kühn, Wilfried; Bozec, Yann; Schiettecatte, Laure-Sophie; Borges, Alberto V.; Baar, Hein J.W. de; Paetsch, J; Kuehn, W

    2009-01-01

    The mechanisms driving the air–sea exchange of carbon dioxide (CO2) in the North Sea are investigated using the three-dimensional coupled physical–biogeochemical model ECOHAM (ECOlogical-model, HAMburg). We validate our simulations using field data for the years 2001–2002 and identify the controls

  13. Terrestrial dissolved organic matter distribution in the North Sea.

    Science.gov (United States)

    Painter, Stuart C; Lapworth, Dan J; Woodward, E Malcolm S; Kroeger, Silke; Evans, Chris D; Mayor, Daniel J; Sanders, Richard J

    2018-07-15

    The flow of terrestrial carbon to rivers and inland waters is a major term in the global carbon cycle. The organic fraction of this flux may be buried, remineralized or ultimately stored in the deep ocean. The latter can only occur if terrestrial organic carbon can pass through the coastal and estuarine filter, a process of unknown efficiency. Here, data are presented on the spatial distribution of terrestrial fluorescent and chromophoric dissolved organic matter (FDOM and CDOM, respectively) throughout the North Sea, which receives organic matter from multiple distinct sources. We use FDOM and CDOM as proxies for terrestrial dissolved organic matter (tDOM) to test the hypothesis that tDOM is quantitatively transferred through the North Sea to the open North Atlantic Ocean. Excitation emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC) revealed a single terrestrial humic-like class of compounds whose distribution was restricted to the coastal margins and, via an inverse salinity relationship, to major riverine inputs. Two distinct sources of fluorescent humic-like material were observed associated with the combined outflows of the Rhine, Weser and Elbe rivers in the south-eastern North Sea and the Baltic Sea outflow to the eastern central North Sea. The flux of tDOM from the North Sea to the Atlantic Ocean appears insignificant, although tDOM export may occur through Norwegian coastal waters unsampled in our study. Our analysis suggests that the bulk of tDOM exported from the Northwest European and Scandinavian landmasses is buried or remineralized internally, with potential losses to the atmosphere. This interpretation implies that the residence time in estuarine and coastal systems exerts an important control over the fate of tDOM and needs to be considered when evaluating the role of terrestrial carbon losses in the global carbon cycle. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  14. Challenging oil bioremediation at deep-sea hydrostatic pressure

    Directory of Open Access Journals (Sweden)

    Alberto Scoma

    2016-08-01

    Full Text Available The Deepwater Horizon (DWH accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (biotechnology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons at deep-sea remain unanswered, as much as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil take up are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled-oil. The fate of solid alkanes (tar and that of hydrocarbons degradation rates was largely overlooked, as the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea, despite being present at hydrocarbon seeps at the Gulf of Mexico. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation.

  15. Radioactive inputs to the North Sea and the Channel

    International Nuclear Information System (INIS)

    1984-01-01

    The subject is covered in sections: introduction (radioactivity; radioisotopes; discharges from nuclear establishments); data sources (statutory requirements); sources of liquid radioactive waste (figure showing location of principal sources of radioactive discharges; tables listing principal discharges by activity and by nature of radioisotope); Central Electricity Generating Board nuclear power stations; research and industrial establishments; Ministy of Defence establishments; other UK inputs of radioactive waste; total inputs to the North Sea and the Channel (direct inputs; river inputs; adjacent sea areas); conclusions. (U.K.)

  16. Regionalization of climate model results for the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Kauker, F.

    1999-07-01

    A dynamical downscaling is presented that allows an estimation of potential effects of climate change on the North Sea. Therefore, the ocean general circulation model OPYC is adapted for application on a shelf by adding a lateral boundary formulation and a tide model. In this set-up the model is forced, first, with data from the ECMWF reanalysis for model validation and the study of the natural variability, and, second, with data from climate change experiments to estimate the effects of climate change on the North Sea. (orig.)

  17. Interannual variability of north Atlantic Sea surface temperatures

    International Nuclear Information System (INIS)

    Bhatt, U.S.; Battisiti, D.S.; Alexander, M.A.

    1994-01-01

    In the midlatitude north Atlantic Ocean the pattern of sea surface temperature anomalies (ssta) is characterized by a north-south dipole. Bjerknes was the first to propose that the banded structure was associated with the interannual variability. Recently, these patterns have been studied more extensively. In this study the quantitative aspects of these patterns are examined through the use of a mixed-layer model (MLM)

  18. Regionalization of climate model results for the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Kauker, F. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany); Storch, H. von [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik

    2000-07-01

    A dynamical downscaling for the North Sea is presented. The numerical model used for the study is the coupled ice-ocean model OPYC. In a hindcast of the years 1979 to 1993 it was forced with atmospheric forcing of the ECMWF reanalysis. The models capability in simulating the observed mean state and variability in the North Sea is demonstrated by the hindcast. Two time scale ranges, from weekly to seasonal and the longer-than-seasonal time scales are investigated. Shorter time scales, for storm surges, are not captured by the model formulation. The main modes of variability of sea level, sea-surface circulation, sea-surface temperature, and sea-surface salinity are described and connections to atmospheric phenomena, like the NAO, are discussed. T106 ''time-slice'' simulations with a ''2 x CO{sub 2}'' horizon are used to estimate the effects of a changing climate on the shelf sea ''North Sea''. The ''2 x CO{sub 2}'' changes in the surface forcing are accompanied by changes in the lateral oceanic boundary conditions taken from a global coupled climate model. For ''2 x CO{sub 2}'' the time mean sea level increases up to 25 cm in the German Bight in the winter, where 15 cm are due to the surface forcing and 10 cm due to thermal expansion. This change is compared to the ''natural'' variability as simulated in the ECMWF integration and found to be not outside the range spanned by it. The variability of sea level on the weekly-to-seasonal time-scales is significantly reduced in the scenario integration. The variability on the longer-than-seasonal time-scales in the control and scenario runs is much smaller then in the ECMWF integration. This is traced back to the use of ''time-slice'' experiments. Discriminating between locally forced changes and changes induced at the lateral oceanic boundaries of the model in the circulation and

  19. Geology and assessment of undiscovered oil and gas resources of the Laptev Sea Shelf Province, 2008

    Science.gov (United States)

    Klett, Timothy; Pitman, Janet K.; Moore, Thomas E.; Gautier, Donald L.

    2017-12-21

    The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the Laptev Sea Shelf Province as part of the 2008 Circum-Arctic Resource Appraisal (CARA) program. The province is situated in the Russian Federation and is located between the Taimyr Peninsula and the Novosibirsk (New Siberian) Islands. Three assessment units (AUs) were defined for this study: the West Laptev Grabens AU, the East Laptev Horsts AU, and the Anisin-Novosibirsk AU, two of which were assessed for undiscovered, technically recoverable resources. The East Laptev Horsts AU was not quantitatively assessed. The estimated mean volumes of undiscovered oil and gas for the Laptev Sea Shelf Province are approximately 3 billion barrels of crude oil, 32 trillion cubic feet of natural gas, and <1 billion barrels of natural gas liquids, all north of the Arctic Circle.

  20. Sea Surface Temperature Climate Data Record for the North Sea and Baltic Sea

    DEFF Research Database (Denmark)

    Høyer, Jacob L.; Karagali, Ioanna

    2016-01-01

    A 30-yr climate data record (CDR) of sea surface temperature (SST) has been produced with daily gap-free analysis fields for the North Sea and the Baltic Sea region from 1982 to 2012 by combining the Pathfinder AVHRR satellite data record with the Along-Track Scanning Radiometer (ATSR) Reprocessing...... for Climate (ARC) dataset and with in situ observations. A dynamical bias correction scheme adjusts the Pathfinder observations toward the ARC and in situ observations. Largest Pathfinder-ARC differences are found in the summer months, when the Pathfinder observations are up to 0.4 °C colder than the ARC...... observations on average. Validation against independent in situ observations shows a very stable performance of the data record, with a mean difference of -0.06 °C compared to moored buoys and a 0.46 °C standard deviation of the differences. The mean annual biases of the SST CDR are small for all years...

  1. Hyperspectral and Radar Airborne Imagery over Controlled Release of Oil at Sea

    Directory of Open Access Journals (Sweden)

    Sébastien Angelliaume

    2017-08-01

    Full Text Available Remote sensing techniques are commonly used by Oil and Gas companies to monitor hydrocarbon on the ocean surface. The interest lies not only in exploration but also in the monitoring of the maritime environment. Occurrence of natural seeps on the sea surface is a key indicator of the presence of mature source rock in the subsurface. These natural seeps, as well as the oil slicks, are commonly detected using radar sensors but the addition of optical imagery can deliver extra information such as thickness and composition of the detected oil, which is critical for both exploration purposes and efficient cleanup operations. Today, state-of-the-art approaches combine multiple data collected by optical and radar sensors embedded on-board different airborne and spaceborne platforms, to ensure wide spatial coverage and high frequency revisit time. Multi-wavelength imaging system may create a breakthrough in remote sensing applications, but it requires adapted processing techniques that need to be developed. To explore performances offered by multi-wavelength radar and optical sensors for oil slick monitoring, remote sensing data have been collected by SETHI (Système Expérimental de Télédection Hyperfréquence Imageur, the airborne system developed by ONERA (the French Aerospace Lab, during an oil spill cleanup exercise carried out in 2015 in the North Sea, Europe. The uniqueness of this dataset lies in its high spatial resolution, low noise level and quasi-simultaneous acquisitions of different part of the EM spectrum. Specific processing techniques have been developed to extract meaningful information associated with oil-covered sea surface. Analysis of this unique and rich dataset demonstrates that remote sensing imagery, collected in both optical and microwave domains, allows estimating slick surface properties such as the age of the emulsion released at sea, the spatial abundance of oil and the relative concentration of hydrocarbons remaining on

  2. Regulation of CO2 Air Sea Fluxes by Sediments in the North Sea

    Science.gov (United States)

    Burt, William; Thomas, Helmuth; Hagens, Mathilde; Brenner, Heiko; Pätsch, Johannes; Clargo, Nicola; Salt, Lesley

    2016-04-01

    A multi-tracer approach is applied to assess the impact of boundary fluxes (e.g. benthic input from sediments or lateral inputs from the coastline) on the acid-base buffering capacity, and overall biogeochemistry, of the North Sea. Analyses of both basin-wide observations in the North Sea and transects through tidal basins at the North-Frisian coastline, reveal that surface distributions of the δ13C signature of dissolved inorganic carbon (DIC) are predominantly controlled by a balance between biological production and respiration. In particular, variability in metabolic DIC throughout stations in the well-mixed southern North Sea indicates the presence of an external carbon source, which is traced to the European continental coastline using naturally-occurring radium isotopes (224Ra and 228Ra). 228Ra is also shown to be a highly effective tracer of North Sea total alkalinity (AT) compared to the more conventional use of salinity. Coastal inputs of metabolic DIC and AT are calculated on a basin-wide scale, and ratios of these inputs suggest denitrification as a primary metabolic pathway for their formation. The AT input paralleling the metabolic DIC release prevents a significant decline in pH as compared to aerobic (i.e. unbuffered) release of metabolic DIC. Finally, long-term pH trends mimic those of riverine nitrate loading, highlighting the importance of coastal AT production via denitrification in regulating pH in the southern North Sea.

  3. Loss of sea ice during winter north of Svalbard

    Directory of Open Access Journals (Sweden)

    Ingrid H. Onarheim

    2014-06-01

    Full Text Available Sea ice loss in the Arctic Ocean has up to now been strongest during summer. In contrast, the sea ice concentration north of Svalbard has experienced a larger decline during winter since 1979. The trend in winter ice area loss is close to 10% per decade, and concurrent with a 0.3°C per decade warming of the Atlantic Water entering the Arctic Ocean in this region. Simultaneously, there has been a 2°C per decade warming of winter mean surface air temperature north of Svalbard, which is 20–45% higher than observations on the west coast. Generally, the ice edge north of Svalbard has retreated towards the northeast, along the Atlantic Water pathway. By making reasonable assumptions about the Atlantic Water volume and associated heat transport, we show that the extra oceanic heat brought into the region is likely to have caused the sea ice loss. The reduced sea ice cover leads to more oceanic heat transferred to the atmosphere, suggesting that part of the atmospheric warming is driven by larger open water area. In contrast to significant trends in sea ice concentration, Atlantic Water temperature and air temperature, there is no significant temporal trend in the local winds. Thus, winds have not caused the long-term warming or sea ice loss. However, the dominant winds transport sea ice from the Arctic Ocean into the region north of Svalbard, and the local wind has influence on the year-to-year variability of the ice concentration, which correlates with surface air temperatures, ocean temperatures, as well as the local wind.

  4. Considering economic and geological uncertainty in the simulation of realistic investment decisions for CO2-EOR projects in the North Sea

    NARCIS (Netherlands)

    Welkenhuysen, Kris; Rupert, Jort; Compernolle, Tine; Ramirez, Andrea|info:eu-repo/dai/nl/284852414; Swennen, Rudy; Piessens, Kris

    2017-01-01

    The use of anthropogenic CO2 for enhancing oil recovery from mature oil fields in the North Sea has several potential benefits, and a number of assessments have been conducted. It remains, however, difficult to realistically simulate the economic circumstances and decisions, while including the

  5. Estimating the effective nitrogen import: An example for the North Sea-Baltic Sea boundary

    Science.gov (United States)

    Radtke, H.; Maar, M.

    2016-10-01

    Semienclosed water bodies such as the Baltic Sea are prone to eutrophication problems. If local nutrient abatement measures are taken to tackle these problems, their success may be limited if a strong nutrient exchange with the adjacent waters exists. The quantification of this exchange is therefore essential to estimate its impact on the ecosystem status. At the example of the Baltic Sea and the North Sea, we illustrate that neither gross transports nor net transports of nutrients have a strong informative value in this context. Instead, we define an "effective import" as the import of nutrients which have not been inside the Baltic Sea before and estimate it in an ecological model with a nutrient-tagging technique. This effective import of bioreactive nitrogen from the Skagerrak to the Kattegat amounts to 103 kt/yr; from Kattegat to Belt Sea it is 54 kt/yr. The nitrogen exchange is therefore 30% stronger than other estimates, e.g., based on import in the deep water, suggest. An isolated view on the Baltic Sea and the North Sea in terms of eutrophication, as it is practiced in management today, is therefore questionable. Nitrogen imported from the North Sea typically spreads eastward up to the Bornholm Basin but can be transported into the deep waters of the Gotland Basin during Major Baltic Inflows in a significant amount.

  6. Ecologically least vulnerable sites for exploration drilling in the Wadden Sea and the North Sea coastal area

    International Nuclear Information System (INIS)

    Lindeboom, H.J.; Bergman, M.J.N.; De Gee, A.

    1996-01-01

    The Dutch Oil Company (NAM, abbreviated in Dutch) applied for a number of exploration drilling in the Dutch part of the Wadden Sea and the North Sea coastal area. NAM is obliged to draft a so-called MER (environmental impact report) to indicate the most environment-friendly alternative for the test drilling. By order of NAM, NIOZ and the IBN-DLO (Institute for Research on Forests and Nature) analyzed samples of the animal life in all the potential sites. Based on the results of the analyses, literature and expert knowledge the ecologically least vulnerable sites and the ecologically least vulnerable season were selected during a workshop. In this report the results are given of the workshop, the field sample analyses and a sailing trip along the sites

  7. Sediment volume in the north polar sand seas of Mars

    International Nuclear Information System (INIS)

    Lancaster, N.; Greeley, R.

    1990-01-01

    Data from studies of the cross-sectional area of terrestrial transverse dunes have been combined with maps of dune morphometry derived from Viking orbiter images to generate new estimates of sediment thickness and dune sediment volume in the north polar sand seas of Mars. A relationship between dune spacing and equivalent sediment thickness (EST) was developed from field data on Namibian and North American dunes and was applied to data on dune spacing and dune cover measured on Viking orbiter images to generate maps of dune sediment thickness for Martian north polar sand seas. There are four major sand seas in the north polar region of Mars, covering an area of 6.8 x 10 5 km 2 . Equivalent sediment thickness ranges between 0.5 and 6.1 m with a mean of 1.8 m. The sand seas contain a total of 1158 km 3 of dune sediment, which may have been derived by erosion of polar layered deposits and concentrated in its present location by winds that change direction seasonally

  8. Arctic fox (Alopex lagopus) from the North Sea

    NARCIS (Netherlands)

    Langeveld, Bram W.; Mol, Dick; van der Plicht, Hans

    2018-01-01

    The first record of arctic fox Alopex lagopus (Linnaeus, 1758) from the Eurogeul area (North Sea) is reported based on a distal humerus fragment collected by private collectors from dredged sediments on ‘De Zandmotor’. It was radiocarbon dated to 29,900 + 550/- 490 BP (GrA-69520), which is younger

  9. The European anchovy (Engraulis encrasicolus) increase in the North Sea

    NARCIS (Netherlands)

    Raab, K.E.

    2013-01-01

    Small pelagic fish such as anchovy are of high socio-economic importance worldwide. They are known for strong fluctuations in abundance, for which the mechanisms are not always understood. European anchovy (Engraulis encrasicolus) increased its population in the North Sea starting in

  10. Anchovy Engraulis encrasicolus diet in the North and Baltic Seas

    NARCIS (Netherlands)

    Raab, K.E.; Nagelkerke, L.A.J.; Boerée, L.A.J.; Rijnsdorp, A.D.; Temming, A.; Dickey-Collas, M.

    2011-01-01

    The diet of anchovy (Engraulis encrasicolus) in the North and Baltic Seas was studied using stomach analysis from four sampling events in different areas. Zooplanktivory was confirmed; the most frequent prey items (in over 40% of stomachs) were copepods, malacostracan larvae and fish larvae. In the

  11. A southern North Sea Miocene dinoflagellate cyst zonation

    NARCIS (Netherlands)

    Munsterman, D.K.; Brinkhuis, H.

    2004-01-01

    An integrated stratigraphical analysis emphasizing organic-walled dinoflagellate cyst (dinocyst) distribution has been carried out on multiple boreholes penetrating the Miocene in the subsurface of the Netherlands (southern North Sea Basin). The bulk of the investigated successions is attributed to

  12. Sleep and Alertness in North Sea Helicopter Operations

    NARCIS (Netherlands)

    Simons, M.; Wilschut, E.S.; Valk, P.J.L.

    2011-01-01

    Introduction : Dutch North Sea helicopter operations are characterized by multiple sector flights to offshore platforms under difficult environmental conditions. In the context of a Ministry of Transport program to improve safety levels of helicopter operations, we assessed effects of pre-duty

  13. Analysis of North Sea Offshore Wind Power Variability

    NARCIS (Netherlands)

    Buatois, A.; Gibescu, M.; Rawn, B.G.; Van der Meijden, M.A.M.M.

    2014-01-01

    This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind

  14. The Potential for Wave Energy in the North Sea

    DEFF Research Database (Denmark)

    Sørensen, H. C.; Chozas, Julia Fernandez

    2010-01-01

    The North Sea has not yet been regarded as prime area for wave energy development in Europe except in Denmark, Benelux and Germany. The reason is the relatively low intensity of waves (12-17kW/m) compared to the Atlantic with a wave climate of 24-48kW/m. Further on the design wave load is almost ...... is resulting in a prediction of a yearly production of 23TWh; the latter is estimating a yearly production of 77TWh. This equals to 6% of the electricity demand around the North Sea, where the annual electricity consumption is about 1,300TWh.......The North Sea has not yet been regarded as prime area for wave energy development in Europe except in Denmark, Benelux and Germany. The reason is the relatively low intensity of waves (12-17kW/m) compared to the Atlantic with a wave climate of 24-48kW/m. Further on the design wave load is almost...... as in the Atlantic and the distance to shore relatively long compared to sites with good wave climate like Ireland, Portugal, Spain and the west coast of UK. The increasing activities within offshore wind in the North Sea and the attempt to build a super grid connecting the wind sites with the major consumers around...

  15. Quaternary evolution of the North Sea and the English Channel

    NARCIS (Netherlands)

    Gibbard, P.L.; Cohen, K.M.

    The island of Britain is surrounded by a ‘moat’ of water, of which the English Channel and the North Sea are two major components. This talk described some major events that occurred to shape these seaways and, in particular, the evidence preserved on the Channel seabed. Here a system of valleys

  16. The maximum significant wave height in the Southern North Sea

    NARCIS (Netherlands)

    Bouws, E.; Tolman, H.L.; Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.

    1995-01-01

    The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is

  17. Temporal Variation of Iodine Isotopes in the North Sea

    DEFF Research Database (Denmark)

    He, Peng; Aldahan, Ala; Possnert, Göran

    2014-01-01

    Monitoring temporal variability of 129I in the North Sea, a relatively large reservoir of radioactive discharges from the nuclear fuel reprocessing facilities, is vital for the environmental situation in the region. New information on concentration levels and distribution of 129I and 127I and the...

  18. Spatial patterns of infauna, epifauna and demersal fish communities in the North Sea.

    NARCIS (Netherlands)

    Reiss, H.; Degraer, S.; Duineveld, G.C.A.; Craeymeersch, J.A.M.

    2010-01-01

    Understanding the structure and interrelationships of North Sea benthic invertebrate and fish communities and their underlying environmental drivers is an important prerequisite for conservation and spatial ecosystem management on scales relevant to ecological processes. Datasets of North Sea

  19. A problem of incentive compatibility in the North Sea petroleum industry

    International Nuclear Information System (INIS)

    Kashani, Hossein A.

    2006-01-01

    The principal-agent relationship between the governments of the UK and Norway, and the multinational oil companies active in the North Sea petroleum industry is, to some extent, different from a typical principal-agent interaction. For almost three decades, the major criterion for allowing a company to take part in the activity was its previous and planned contribution to the domestic economy by means of applying the highest possible domestic inputs. This study applies mathematical modeling to show that the authorities had the opportunity to offer an incentive scheme to persuade the oil companies to involve domestic suppliers at the governments' preferred level. Unlike a typical government regulatory framework, which aims to increase efficiency in terms of price and/or quality, the incentive compatible scheme discussed in this paper could, in certain circumstances, generate inefficiency in the daily operation of the oil and gas fields

  20. The latest oil spills in the Mediterranean Sea

    International Nuclear Information System (INIS)

    Bergueiro Lopez, J.R.; Morales Correas, N.; Dominguez Laseca, F.

    1992-01-01

    The oil spills from the Agip Abruzzo and the Haven in April 1991 are described. The Agip Abruzzo collided with a ferry near Livorno, Italy and spilled 3,000 tonnes of Iranian crude oil. Another 12,000 tonnes burned and 140 people were killed in the incident. The spill had little effect on the sea environment as most of the spilled oil was removed. The Haven oil tanker exploded just after unloading crude oil at Arenzano, Italy, spilling 3,000 tonnes of oil along the Ligurian coast. A series of nine explosions occurred over the next few days and the ship finally sank in 60 m of water. Spill cleanup procedures used at sea and along the affected coast are reviewed. Crude oil residues drifting along the coast of the Balearic Islands were sampled and analyzed in May and July 1991 to determine whether they came from the Haven tanker. Experiments were also conducted to determine the evaporated fraction of heavy Iranian crude oil as a function of time when spilled on sea water or different sizes of beach sand. The analyzed samples were concluded not to have come from the Haven spill. 9 refs., 9 figs., 1 tab

  1. Status and perspectives of fish industry of Azerbaijan in conditions of increased oil and gas extraction in the Caspian Sea

    International Nuclear Information System (INIS)

    Gadjiev, R.V; Kasimov, R.Yu; Akhundov, M.M; Karaev, A.I.

    2002-01-01

    Full text:The Caspian Sea plays important role in supply of the population of Azerbaijan Republic with fish products. Furthermore, the Caspian Sea is the single pond where more than 70% of sturgeons are harvested all over the world. Besides, more than 80% of the big bony fishes harvested in the ponds of Azerbaijan, are caught in the Caspian Sea. On the other hand, the entrails of the Caspian Sea contain tremendous amounts of oil and gas deposits whose extraction disturbs partially the ecological equilibrium in this unique pond. It should be noticed that since 1973-1974 the increase of sturgeon harvest was observed. The special scientific Institute of Fish Industry in Astrakhan city with its branch in Azerbaijan was founded. In the same years top amount of oil was extracted in the Caspian Sea and simultaneously high pollution level of the sea with oil and oil products, having been clearly seen in the Sea-attached Boulevard, was fixed. However, in spite of these unfavorable conditions, the sturgeon harvests, due to their reproduction in the hatcheries and following release into the sea, increased not only in Azerbaijan, but also all over the whole Caspian Sea basin. It is impossible to keep serenity today owing to the fact that broadening of oil extraction in the Caspian Sea for new deposits are situated near to the fattening areas of juveniles of valuable fish species, in the estuary of the Kura river and other small rivers where sex-mature fishes migrate. Besides, the migration ways of sturgeons the North origin pass through these zones: in autumn- from the North to the South, while in early and middle spring- in opposite direction

  2. The Sea Empress oil spill: cytochrome P450 levels, ethoxyresorufin O-deethylase activity and bile metabolites in migrating sea trout

    International Nuclear Information System (INIS)

    Bird, D.J.; Rotchell, J.M.; Newton, L.C.

    1997-06-01

    Following concern that migrating sea trout in the Afon Tywi and Eastern Cleddau in Wales may have been exposed to oil from the Sea Empress, either directly or via their food, biomarkers of oil pollution were investigated in 14 fish from these rivers and compared with 8 fish from that of a control on the River Dee in North Wales. Sea trout 'whitling' were collected by electrofishing from the tidal limits of each river in later August/early September, 1996. The mean total cytochrome P450 content in the livers were not significantly different between fish from the Tywi (341 pmol mg -1 protein), Cleddau (212 pmol mg -1 protein) or from those caught in the Dee (121 pmol mg -1 protein). The report concludes that some individual sea trout from the rivers Tywi and Cleddau may have been exposed to oil from the Sea Empress while feeding in estuarine waters. However, by the time they were captured in these rivers, compared to control fish caught in the Dee, differences between the mean P450 content, mean EROD activity and the bile metabolite profiles were not apparent. There was no evidence that the Sea Empress oil spill had serious detrimental effects on populations of migrating sea trout in Welsh rivers. (author)

  3. Development of an oil skimming and separating system to combat oil spills at sea

    Energy Technology Data Exchange (ETDEWEB)

    Klimek, R.; Clauss, G.

    1983-02-01

    For efficiently combatting oil pollution at sea, it is intended to combine a hopper dredger with two oil skimmers. This system consists of two oil skimmers, which are permanently stowed on deck of the ship. In case of operation, the oil skimmers work connected beside the ship, but decoupled from the ship concerning motions of sea. Hopper dredgers have already sufficient pump and tank capacity and are well-suited for operation in offshore areas and river deltas. They are characterized by low draught and are capable of lightening their cargo very quickly so that they are ready for oil skimming operation within 2 hours. Model tests with regard to the behaviour and function of the oil skimmer system were carried out at scales of 1:15, 1:10, and 1:5. Tests with the system ship/oil skimmer were performed at a scale of 1:15.

  4. Variability of North Sea pH and CO2 in response to North Atlantic Oscillation forcing

    DEFF Research Database (Denmark)

    Salt, Lesley A.; Thomas, Helmuth; Prowe, Friederike

    2013-01-01

    [1] High biological activity causes a distinct seasonality of surface water pH in the North Sea, which is a strong sink for atmospheric CO2 via an effective shelf pump. The intimate connection between the North Sea and the North Atlantic Ocean suggests that the variability of the CO2 system...... of the North Atlantic Ocean may, in part, be responsible for the observed variability of pH and CO2 in the North Sea. In this work, we demonstrate the role of the North Atlantic Oscillation (NAO), the dominant climate mode for the North Atlantic, in governing this variability. Based on three extensive...... observational records covering the relevant levels of the NAO index, we provide evidence that the North Sea pH and CO2 system strongly responds to external and internal expressions of the NAO. Under positive NAO, the higher rates of inflow of water from the North Atlantic Ocean and the Baltic outflow lead...

  5. Storing CO2 under the North Sea Basin - A key solution for combating climate change

    International Nuclear Information System (INIS)

    Skogen, T; Morris, B; Agerup, M; Svenningsen, S Oe; Kropelien, K F; Solheim, M; Northmore, B; Dixon, T; O'Carroll, K; Greaves, A; Golder, J; Selmer-Olsen, S; Sjoeveit, A; Kaarstad, O; Riley, N; Wright, I; Mansfield, C

    2007-06-01

    This report represents the first deliverable of the North Sea Basin Task Force, which Norway and the UK established in November 2005 to work together on issues surrounding the transport and storage of CO 2 beneath the North Sea. The North Sea represents the best geological opportunity for storing our CO 2 emissions away from the atmosphere for both the UK and Norway

  6. Combining airborne and satellite remote sensing programs to repress illegal oil discharges in restricted sea areas

    International Nuclear Information System (INIS)

    Price, M.

    2005-01-01

    An airborne surveillance program has been conducted over the Belgian part of the North Sea since 1991. The role of the program is to detect infringements on the Marpol Convention via remote sensing, and to take legal action against polluters through the use of recorded observations. Although Belgium has a restricted sea area of about 3,500 km with no fixed offshore oil installations, a pollution risk is constantly present due to 2 dense traffic separation schemes close to the shoreline. The Belgian marine areas and adjacent waters are regularly scanned with a Side Looking Airborne Radar (SLAR) on board a remote sensing aircraft. This paper describes an evaluation trial that the Belgian Management Unit of the North Sea Mathematical Models (MUMM) joined in 2004, together with various agencies from the United Kingdom, Germany and the Netherlands. The trial consists of a cost-sharing satellite service for oil detection with ENVISAT ASAR data. The trial was co-funded by the European Space Agency (ESA) and run by Kongsberg Satellite Services. MUMM's objective was to evaluate the effectiveness and operational character of satellite services for detecting oil spills at sea. The results of the 3 month trial have indicated that aerial remote sensing for the detection of illegal oil discharges at sea increases the chances of catching polluters more efficiently, with improved chances of evidence collecting. It was concluded that when various services are integrated and strict operational conditions are met, satellite services may prove to be valuable in restricted, very densely navigated national waters that are easily reached by airborne means. 12 refs., 8 tabs., 3 figs

  7. Mechanisms of long-term mean sea level variability in the North Sea

    Science.gov (United States)

    Dangendorf, Sönke; Calafat, Francisco; Øie Nilsen, Jan Even; Richter, Kristin; Jensen, Jürgen

    2015-04-01

    We examine mean sea level (MSL) variations in the North Sea on timescales ranging from months to decades under the consideration of different forcing factors since the late 19th century. We use multiple linear regression models, which are validated for the second half of the 20th century against the output of a state-of-the-art tide+surge model (HAMSOM), to determine the barotropic response of the ocean to fluctuations in atmospheric forcing. We demonstrate that local atmospheric forcing mainly triggers MSL variability on timescales up to a few years, with the inverted barometric effect dominating the variability along the UK and Norwegian coastlines and wind (piling up the water along the coast) controlling the MSL variability in the south from Belgium up to Denmark. However, in addition to the large inter-annual sea level variability there is also a considerable fraction of decadal scale variability. We show that on decadal timescales MSL variability in the North Sea mainly reflects steric changes, which are mostly remotely forced. A spatial correlation analysis of altimetry observations and baroclinic ocean model outputs suggests evidence for a coherent signal extending from the Norwegian shelf down to the Canary Islands. This supports the theory of longshore wind forcing along the eastern boundary of the North Atlantic causing coastally trapped waves to propagate along the continental slope. With a combination of oceanographic and meteorological measurements we demonstrate that ~80% of the decadal sea level variability in the North Sea can be explained as response of the ocean to longshore wind forcing, including boundary wave propagation in the Northeast Atlantic. These findings have important implications for (i) detecting significant accelerations in North Sea MSL, (ii) the conceptual set up of regional ocean models in terms of resolution and boundary conditions, and (iii) the development of adequate and realistic regional climate change projections.

  8. The Cenozoic geological evolution of the Central and Northern North Sea based on seismic sequence stratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Jordt, Henrik

    1996-03-01

    This thesis represents scientific results from seismic sequence stratigraphic investigations. These investigations and results are integrated into an ongoing mineralogical study of the Cenozoic deposits. the main results from this mineralogical study are presented and discussed. The seismic investigations have provided boundary conditions for a forward modelling study of the Cenozoic depositional history. Results from the forward modelling are presented as they emphasise the influence of tectonics on sequence development. The tectonic motions described were important for the formation of the large oil and gas fields in the North Sea.

  9. Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19 by multiple Soviet Union institutes (NODC Accession 0077413)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, and nutrients data collected from North Atlantic Ocean, White Sea, Mediterranean Sea, Black Sea, and Sea of Azov from 1924-03-19 to 1989-11-19...

  10. Job retention in the British offshore sector through greening of the North Sea energy industry

    International Nuclear Information System (INIS)

    Esteban, Miguel; Leary, David; Zhang, Qi; Utama, Agya; Tezuka, Tetsuo; Ishihara, Keiichi N.

    2011-01-01

    For the case of the UK there are currently three ways of obtaining energy from sea areas, namely from wind, tides and waves. A methodology was developed to determine the future size of the offshore renewable industry based on the concept of employment factor, or the number of people required to maintain each unit of electricity production. An assessment was made of the decline in the number of people employed in oil related jobs in the North Sea and the gap that this could create in the UK's economy unless this pool of offshore expertise could find an alternative employment in the renewable sector. The paper will also investigate the effect of gradually transforming the UK's oil and gas sector into offshore renewables. If this was to happen by 2050 the UK offshore renewable industry could produce between 127 and 146 TWh of electricity, equivalent to around 57-66% of the current energy consumption in the country. - Research highlights: → There are three possible sources of energy from sea areas in the UK: wind, tide and waves. → As the number of jobs in the offshore oil industry reduces they should be compensated with jobs in the renewable offshore sector. → By 2050 the UK offshore renewable industry could produce between 127 and 146TWh of electricity. → This would represent around 57-66% of the current energy consumption in the UK.

  11. The impact of the 'Sea Empress' oil spill on seabass recruitment

    International Nuclear Information System (INIS)

    Lancaster, J.E.; Pawson, M.G.; Pickett, G.D.; Jennings, S.

    1998-01-01

    Young-of-the-year (O-group) sea bass (Dicentrarchus labrax L.) were collected during 1996 from 12 inshore sites in the Bristol Channel in order to investigate possible effects of the Sea Empress oil spill on their growth and survival. O-group bass were more abundant on the south side of the Bristol Channel than in South Wales nurseries, and particularly scarce within Milford Haven. Some bass caught in nursery areas on the north Cornish coast had spawned in early March, but only fish spawned after late April appeared in South Wales nurseries, where the first arrival data of bass post-larvae was later than in nursery areas in north Devon and Cornwall. O-group bass grew faster within the latter nurseries than in the north coast of the Bristol Channel, where a much higher proportion of fish failed to reach 60 mm, the critical length for survival through the first winter. There were no significant differences in fish condition or in the weight of their stomach contents between sites. Whilst the Sea Empress oil spill may have contributed to the differences in the survival of early-spawned bass larvae and the abundance of O-group bass in nursery areas on either side of the Bristol Channel, these differences are likely to be less significant than the year to year variation due to natural causes. (author)

  12. Geology and assessment of undiscovered oil and gas resources of the North Kara Basins and Platforms Province, 2008

    Science.gov (United States)

    Klett, Timothy R.; Pitman, Janet K.; Moore, T.E.; Gautier, D.L.

    2017-11-15

    The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the North Kara Basins and Platforms Province as part of the its Circum-Arctic Resource Appraisal. This geologic province is north of western Siberia, Russian Federation, in the North Kara Sea between Novaya Zemlya to the west and Severnaya Zemlya to the east. One assessment unit (AU) was defined, the North Kara Basins and Platforms AU, which coincides with the geologic province. This AU was assessed for undiscovered, technically recoverable resources. The total estimated mean volumes of undiscovered petroleum resources in the province are ~1.8 billion barrels of crude oil, ~15.0 trillion cubic feet of natural gas, and ~0.4 billion barrels of natural-gas liquids, all north of the Arctic Circle.

  13. CRUDE OIL TRANSPORT FROM THE CASPIAN SEA REGION TO EUROPE

    Directory of Open Access Journals (Sweden)

    Adam Przybyłowski

    2014-07-01

    Full Text Available In the contemporary world, despite the growing importance and scale of the use of renewable energy , conventional energy resources still play a huge role. The European Union countries are dependent on the oil imports and the their main supplier of crude oil and natural gas has been the Russian Federation. After the collapse of the Soviet Union , the Caspian Sea region has become an alternative to Russian energy resources. The Unit-ed States , European Union, China and many other countries have shown their interest about this region. Despite a relatively large oil and natural gas reserves, the export of the-se commodities to the West is still problematic. Based on the available data and infor-mation, the publication explores the issue of energy resources transport directions with a particular emphasis on the crude oil from the Caspian Sea region to Europe.

  14. Illicit drugs and their metabolites in 36 rivers that drain into the Bohai Sea and north Yellow Sea, north China.

    Science.gov (United States)

    Wang, De-Gao; Zheng, Qiu-Da; Wang, Xiao-Ping; Du, Juan; Tian, Chong-Guo; Wang, Zhuang; Ge, Lin-Ke

    2016-08-01

    Illicit drugs and their metabolites have recently been recognized as an emerging group of contaminants due to their potential ecotoxicological impact in aquatic ecosystems. To date, information on the occurrence of these compounds in the aquatic environment of China remains limited. In this study, we collected surface water samples from 36 rivers in north China that discharge into the Bohai Sea and north Yellow Sea and measured the concentrations of amphetamine-like compounds, ketamines, cocainics, and opioids. The occurrence and spatial patterns of these substances show significant differences between the rivers and regions. Two designer drugs, methamphetamine (METH) and ketamine (KET), were the most abundant compounds detected in the entire set of samples (detection frequency of 92 and 69 %). The concentrations of METH and KET ranged from illicit drugs consumed in China. The high concentrations of these illicit drugs and their metabolites were found in areas that have a high population density. The riverine input of total illicit drugs into the Bohai Sea and north Yellow Sea was estimated to be in the range of 684 to 1160 kg per year.

  15. Countermeasure Study on Deep-sea Oil Exploitation in the South China Sea——A Comparison between Deep-sea Oil Exploitation in the South China Sea and the Gulf of Mexico

    Science.gov (United States)

    Zhao, Hui; Qiu, Weiting; Qu, Weilu

    2018-02-01

    The unpromising situation of terrestrial oil resources makes the deep-sea oil industry become an important development strategy. The South China Sea has a vast sea area with a wide distribution of oil and gas resources, but there is a phenomenon that exploration and census rates and oil exploitation are low. In order to solve the above problems, this article analyzes the geology, oil and gas exploration and exploration equipment in the South China Sea and the Gulf of Mexico. Comparing the political environment of China and the United States energy industry and the economic environment of oil companies, this article points out China’s deep-sea oil exploration and mining problems that may exist. Finally, the feasibility of oil exploration and exploitation in the South China Sea is put forward, which will provide reference to improve the conditions of oil exploration in the South China Sea and promoting the stable development of China’s oil industry.

  16. Two centuries of extreme events over the Baltic Sea and North Sea regions

    Science.gov (United States)

    Stendel, Martin; den Besselaar Else, van; Abdel, Hannachi; Jaak, Jaagus; Elizabeth, Kent; Christiana, Lefebvre; Gudrun, Rosenhagen; Anna, Rutgersson; Frederik, Schenk; der Schrier Gerard, van; Tim, Woolings

    2017-04-01

    Two centuries of extreme events over the Baltic Sea and North Sea regions In the framework of the BACC 2 (for the Baltic Sea) and NOSCCA projects (for the North Sea region), studies of past and present variability and changes in atmospheric variables within the North Sea region over the instrumental period (roughly the past 200 years) have been investigated. Findings on trends in temperature and precipitation have already been presented. Here we focus on data homogeneity issues and examine how reliable reanalyses are in this context. Unlike most other regions in the world, there is a wealth of old observations available for the Baltic and North Sea regions, most of it in handwritten form in meteorological journals and other publications. These datasets need to be carefully digitised and homogenized. For this, a thorough quality control must be applied; otherwise the digitised datasets may prove useless or even counterproductive. We present evidence that this step cannot be conducted without human interference and thus cannot be fully automated. Furthermore, inhomogeneities due to e.g. instrumentation and station relocations need to be addressed. A wealth of reanalysis products is available, which can help detect such inhomogeneities in observed time series, but at the same time are prone to biases and/or spurious trends themselves e.g. introduced by changes in the availability and quality of the underlying assimilated data. It therefore in general remains unclear in how far we can simulate the pre-satellite era with respect to homogeneity with reanalyses based only on parts of the observing system. Extreme events and changes in extreme situations are more important and of greater (societal) significance than changes in mean climate. However, changes in extreme weather events are difficult to assess not only because they are, per definition, rare events, but also due to the homogeneity issues outlined above. Taking these into account, we present evidence for changes

  17. Research on a dispersing solution for burnt crude oils: Aegean Sea oil spill

    International Nuclear Information System (INIS)

    Bergueiro, J.R.; Morales, N.; Dominguez, F.

    1993-01-01

    The oil tanker Aegean Sea spilled oil when it grounded during severe storm conditions near La Coruna, Spain. Much of the oil burned after an explosion was caused by the hull breaking apart. Oil which contaminated several beaches was affected by both combustion and weathering. Experiments were conducted on oil sampled from the beaches to investigate dispersion of the oil using Beep Enersperse 1990 at different shaking speeds. Biodegradation experiments were also conducted in the presence of Beep Enersperse 1990 but with seawater absent. Although emulsification of the burnt and weathered oil was very difficult, good dispersion and biodegradation were obtained. After 42 d in a stirred reactor, biodegradation of the oil reached at least 80%. 3 refs., 3 figs., 4 tabs

  18. Ecology of the North Sea: Problems, successes, failures, future needs

    Science.gov (United States)

    Kinne, O.

    1995-03-01

    After defining ‘ecology’, outlining the basic categories of ecological research and listing examples of modern ecological investigations, this introductory paper focusses on basic considerations; it is, in essence, a programmatic contribution. Research details on the ecology of the North Sea are the subject of the following papers. The problems of ecological North Sea research are formidable. Hydrological and biological fluctuations and variabilities are pronounced. Exchange patterns with the Atlantic are complex, and the inputs of rivers and rain defy exact measurement and prediction. Season, weather, climate—and as yet insufficiently known and controlled human-caused impacts—further complicate the situation. All this results in an unusually high degree of uncertainty. New questions and problems arise before the old ones can be answered or solved. Nevertheless, ecological North Sea research has achieved many successes. The North Sea is the most intensively investigated sea area on our planet. Generations of zoologists, botanists and hydrographers — and more recently microbiologists, meteorologists, climatologists, chemists, pathologists and toxicologists — have produced an impressive body of knowledge. Slowly we are beginning to understand the forces that govern energy budgets and balances, material fluxes, and the factors that control and direct ecosystem dynamics. Essential driving forces of ecosystem dynamics result from microbial, especially bacterial, activities. Ecological modelling has paved the way for new theories and insights, and holds promise for progress towards a predictive ecology. Failures and shortcomings include insufficient long-term research, inadequately designed experiments, and misconceptions in environmental protection. Net changes in ecological processes of an heterogeneous and intensely varying environment such as the North Sea can only be comprehended adequately against the background of sustained measurements over decades

  19. North African oil and foreign investment in changing market conditions

    International Nuclear Information System (INIS)

    Fattouh, Bassam; Darbouche, Hakim

    2010-01-01

    Since the 1960s, the experiences of the North African oil producers of Libya, Algeria, Egypt and Sudan within the oil industry have followed separate paths, which have led them into different relations with foreign oil companies. While reflecting broader trends of 'resource nationalism', these relations have also been affected by a number of factors specific to these countries. In tracing the evolution of the oil investment frameworks of these countries, as well as their concomitant relations with IOCs, this paper probes the roles played by these factors and argues that the type and size of remaining reserves as well as the capability of NOCs are likely to determine the most future developments in the region's oil industry.

  20. Maps of mesoscale wind variability over the North Sea region

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Hahmann, Andrea N.; Badger, Jake

    Mesoscale wind fluctuations affect the operation of wind farms, particularly as the number of geographically concentrated wind farms in the North Sea increases (Akhmatov et al. 2007). The frequency and intensity of wind fluctuations could be considered as a new siting criterion, together with exi...... for a 1 year period. The model was run with a horizontal grid spacing of 2 km. The variability maps are created by integrating the average 24 hour spectra at every grid point over different time-scales....

  1. A synthesis of Cenozoic sedimentation in the North Sea

    DEFF Research Database (Denmark)

    Anell, Ingrid Anna Margareta; Thybo, Hans; Rasmussen, E.S.

    2012-01-01

    study provides a regional synthesis of sedimentation based on a comprehensive interpretation of a regionally covering reflection seismic data set. We relate observations of sediment characteristics and unconformities to the geological evolution. The timing, regional expression and stratigraphic...... characteristics of many unconformities indicate that they were generated by eustatic sea-level fall, often in conjunction with other processes. Early Cenozoic unconformities, however, relate to tectonism associated with the opening of the North Atlantic. From observation on a regional scale, we infer...

  2. North Sea market update: Changes in both concept and content

    International Nuclear Information System (INIS)

    Scruton, M.; Bru, J.G.

    1997-01-01

    The current paradox facing the North Sea offshore industry is that while it is experiencing a current market boom, within two years contractors may be scrambling around in a much reduced market. West Europe is running at a massive $15.1 billion. A veritable feast giving contractors, especially in Norway, a full workload and the headache of a severe skilled workforce shortage. Themes discussed cover Norwegian needs, Danish developments, UK utilisation, Dutch demand, and new breed. 4 figs

  3. Airborne gravity survey of Lincoln Sea and Wandel Sea, north Greenland

    DEFF Research Database (Denmark)

    Olesen, Arne Vestergaard; Forsberg, René; Keller, K.

    2000-01-01

    In June 1998 National Survey and Cadastre Denmark (KMS) carried out an airborne gravity survey over the Polar Sea to the north of Greenland. A Twin Otter from Greenlandair, equipped with autopilot and additional fuel tanks, was employed for the survey. A modified marine LaCoste & Romberg gravimet...

  4. Climate change in the North and the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Rottem, Svein Vigeland; Moe, Arild

    2007-11-15

    How will climate change affect oil industry operations in the High North? The report analyses impacts in the North that are different from, or come in addition to, the impacts felt globally, from two angles: One outlining climate-related changes in nature and their impacts on oil industry operations, and the second discussing actual and possible policy responses and their impact. Forecasts and scenarios developed by climate scientists indicate that the situation is volatile. The climate and weather will be less predictable. Although the long term tendency is clear, there will be large variations in ice from year to year, with some seasons colder and with more ice than what has been 'normal' in recent years. The industry cannot count on areas remaining ice-free, and when it comes to fixed installations it will have to prepare for a situation in 2030 with maximum ice not much different than today. Climate policies are not likely to have a strong direct impact on the operations of oil companies in the north, but the climate development in the North is likely to impact other political processes, public opinion and consumers. In turn they may affect the conditions for oil industry operations. (author). 49 refs., 7 figs

  5. The North Atlantic Oscillation: variability and interactions with the North Atlantic ocean and Artic sea ice

    Energy Technology Data Exchange (ETDEWEB)

    Jung, T

    2000-07-01

    The North Atlantic oscillation (NAO) represents the dominant mode of atmospheric variability in the North Atlantic region and describes the strengthening and weakening of the midlatitude westerlies. In this study, variability of the NAO during wintertime and its relationship to the North Atlantic ocean and Arctic sea ice is investigated. For this purpose, observational data are analyzed along with integrations of models for the Atlantic ocean, Arctic sea ice, and the coupled global climate system. From a statistical point of view, the observed NAO index shows unusually high variance on interdecadal time scales during the 20th century. Variability on other time scales is consistent with realizations of random processes (''white noise''). Recurrence of wintertime NAO anomalies from winter-to-winter with missing signals during the inbetween nonwinter seasons is primarily associated with interdecadal variability of the NAO. This recurrence indicates that low-frequency changes of the NAO during the 20th century were in part externally forced. (orig.)

  6. First report of the planktonic copepod Oithona davisae in the northern Wadden Sea (North Sea): Evidence for recent invasion?

    Science.gov (United States)

    Cornils, Astrid; Wend-Heckmann, Britta

    2015-06-01

    In October 2010, specimens of Oithona were taken from the List Tidal Basin in the northern Wadden Sea (North Sea) for a biogeographic study on Oithona similis. These specimens could not be assigned to O. similis or any of the other Oithona species known from the North Sea genetically. These specimens were identified as Oithona davisae Ferrari and Orsi 1984, a Northwest Pacific species, known as an invasive species from the Black Sea and the northwestern Mediterranean Sea. Recent sampling provided evidence that O. davisae is still present in the northern Wadden Sea and may thus now be a permanent plankton species.

  7. Regulatory policies for using oil dispersants in the Barents Sea

    Directory of Open Access Journals (Sweden)

    Natalia Belkina

    2015-04-01

    Full Text Available Use of dispersants requires assessment of which environmental values are at stake. In the Barents Sea this issue is of high concern as large oil spills can cause transboundary pollution, affecting the interests of two neighbouring countries. The Joint Contingency Plan in the Barents Sea does not set any specific requirements for use of dispersants and lets Norway and Russia follow their national procedures. The Plan emphasizes that in case of transboundary pollution the decision to use dispersants shall only be undertaken upon common agreement. The paper presents a comparison of the national regulatory approaches of Norway and Russia to using dispersants. The research is based on the analysis of legislative documents and interviews with oil companies, oil spill responders and relevant national authorities. The research reveals that in both countries use of dispersants requires preliminary authorization of the national agencies. In Norway the pre-approval procedure and the algorithm of dispersants involvement in response to a real accident are clearly documented and are regularly tested. This has made the process of approval for using dispersants more efficient. In Russia the lack of practical experience in using dispersants and well-established approval procedures can result in a long and unclear permitting process for each oil spill case. This could seriously hinder the use of dispersants to combat transboundary pollution in the Barents Sea, even if it is considered to be beneficial. We conclude that the development of a harmonized approach for dispersants use in the Barents Sea should be thoroughly assessed.

  8. Temperature and salinity profile data collected by bottle on multiple cruises in the Baltic Sea, Baffin Bay, Davis Strait, the North Atlantic Ocean, and the North Sea from 02 January 1985 to 13 November 1989 (NODC Accession 0000056)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and nutrients data were collected using bottle casts from DANA and other platforms in Baffin Sea, Baltic Sea, Davis Strait, North Sea, and North...

  9. Insight conference reports : Far north oil and gas forum

    International Nuclear Information System (INIS)

    2005-01-01

    The emerging issues and opportunities for developing oil and gas resources in the North were outlined during this conference, along with recent developments, the current climate from an exploration perspective and the current state of play in the North. It highlighted Yukon's oil and gas potential and emphasized the importance of both the Mackenzie Gas Project and the Alaska Highway Pipeline Project. The activities of gas producers, pipeline proponents and governments regarding the construction of gas pipelines to connect northern gas to markets in North America were reviewed along with net fiscal and social benefits; community and First Nations' involvement; federal regulatory processes that have First Nations support; and securing federal funding to help prepare for the pipelines. The conference featured 19 presentations, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs

  10. Modeling the buoyancy-driven Black Sea Water outflow into the North Aegean Sea

    Directory of Open Access Journals (Sweden)

    Nikolaos Kokkos

    2016-04-01

    Full Text Available A three-dimensional numerical model was applied to simulate the Black Sea Water (BSW outflux and spreading over the North Aegean Sea, and its impact on circulation and stratification–mixing dynamics. Model results were validated against satellite-derived sea surface temperature and in-situ temperature and salinity profiles. Further, the model results were post-processed in terms of the potential energy anomaly, ϕ, analyzing the factors contributing to its change. It occurs that BSW contributes significantly on the Thracian Sea water column stratification, but its signal reduces in the rest of the North Aegean Sea. The BSW buoyancy flux contributed to the change of ϕ in the Thracian Sea by 1.23 × 10−3 W m−3 in the winter and 7.9 × 10−4 W m−3 in the summer, significantly higher than the corresponding solar heat flux contribution (1.41 × 10−5 W m−3 and 7.4 × 10−5 W m−3, respectively. Quantification of the ϕ-advective term crossing the north-western BSW branch (to the north of Lemnos Island, depicted a strong non-linear relation to the relative vorticity of Samothraki Anticyclone. Similar analysis for the south-western branch illustrated a relationship between the ϕ-advective term sign and the relative vorticity in the Sporades system. The ϕ-mixing term increases its significance under strong winds (>15 m s−1, tending to destroy surface meso-scale eddies.

  11. Warming in the Nordic Seas, North Atlantic storms and thinning Arctic sea ice

    Science.gov (United States)

    Alexeev, Vladimir A.; Walsh, John E.; Ivanov, Vladimir V.; Semenov, Vladimir A.; Smirnov, Alexander V.

    2017-08-01

    Arctic sea ice over the last few decades has experienced a significant decline in coverage both in summer and winter. The currently warming Atlantic Water layer has a pronounced impact on sea ice in the Nordic Seas (including the Barents Sea). More open water combined with the prevailing atmospheric pattern of airflow from the southeast, and persistent North Atlantic storms such as the recent extremely strong Storm Frank in December 2015, lead to increased energy transport to the high Arctic. Each of these storms brings sizeable anomalies of heat to the high Arctic, resulting in significant warming and slowing down of sea ice growth or even melting. Our analysis indicates that the recently observed sea ice decline in the Nordic Seas during the cold season around Svalbard, Franz Joseph Land and Novaya Zemlya, and the associated heat release from open water into the atmosphere, contributed significantly to the increase in the downward longwave radiation throughout the entire Arctic. Added to other changes in the surface energy budget, this increase since the 1960s to the present is estimated to be at least 10 W m-2, which can result in thinner (up to at least 15-20 cm) Arctic ice at the end of the winter. This change in the surface budget is an important contributing factor accelerating the thinning of Arctic sea ice.

  12. Priority volatile organic compounds in surface waters of the southern North Sea

    International Nuclear Information System (INIS)

    Huybrechts, Tom; Dewulf, Jo; Langenhove, Herman van

    2005-01-01

    The occurrence of 25 volatile organic compounds (VOCs) was studied from April 1998 to October 2000 in the southern North Sea. Target VOCs were selected from lists of priority pollutants for the marine environment and included, e.g., chlorinated short-chain hydrocarbons (CHCs), monocyclic aromatic hydrocarbons (MAHs), and chlorinated monocyclic aromatic hydrocarbons (CMAHs). Water samples were taken from the Channel, the Belgian Continental Shelf, the mouth of the Scheldt estuary and the Southern Bight, and were analysed by purge-and-trap and high-resolution gas chromatography-mass spectrometry. All data were produced by analyses deemed 'in control' by a rigorous quality assurance/quality control program provided by QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring in Europe). Chloroform and trichloroethene were commonly detected at concentrations up to 1900 and 270 ng l -1 , respectively. The other CHCs were generally found below 5 ng l -1 , and rarely exceeded 10 ng l -1 . Concentrations of MAHs were at least one order of magnitude higher than those of the CHCs. The higher levels were attributed to anthropogenic emissions from oil-related activities in coastal areas. CMAHs, except chlorobenzene and 1,4-dichlorobenzene, were hardly detected in North Sea waters. The levels of several CHCs and MAHs were shown to decrease compared to previous investigations in 1994-1995, probably as a result of on-going emission reduction efforts. The occurrence of 1,1,1-trichloroethane, for instance, was substantially reduced since the Montreal Protocol was implemented in 1995. - Volatile aromatics are a major group of volatile organic compounds in the North Sea, and are attributed to discharges from shipping and oil related activities

  13. Application of magnetic techniques to lateral hydrocarbon migration - Lower Tertiary reservoir systems, UK North Sea

    Science.gov (United States)

    Badejo, S. A.; Muxworthy, A. R.; Fraser, A.

    2017-12-01

    Pyrolysis experiments show that magnetic minerals can be produced inorganically during oil formation in the `oil-kitchen'. Here we try to identify a magnetic proxy that can be used to trace hydrocarbon migration pathways by determining the morphology, abundance, mineralogy and size of the magnetic minerals present in reservoirs. We address this by examining the Tay formation in the Western Central Graben in the North Sea. The Tertiary sandstones are undeformed and laterally continuous in the form of an east-west trending channel, facilitating long distance updip migration of oil and gas to the west. We have collected 179 samples from 20 oil-stained wells and 15 samples from three dry wells from the British Geological Survey Core Repository. Samples were selected based on geological observations (water-wet sandstone, oil-stained sandstone, siltstones and shale). The magnetic properties of the samples were determined using room-temperature measurements on a Vibrating Sample Magnetometer (VSM), low-temperature (0-300K) measurements on a Magnetic Property Measurement System (MPMS) and high-temperature (300-973K) measurements on a Kappabridge susceptibility meter. We identified magnetite, pyrrhotite, pyrite and siderite in the samples. An increasing presence of ferrimagnetic iron sulphides is noticed along the known hydrocarbon migration pathway. Our initial results suggest mineralogy coupled with changes in grain size are possible proxies for hydrocarbon migration.

  14. The economics of CO2-EOR cluster developments in the UK Central North Sea

    International Nuclear Information System (INIS)

    Kemp, Alexander G.; Kasim, Sola

    2013-01-01

    Studies to date have generally shown that individual CO 2 -EOR offshore projects are uneconomic except under questionable assumptions. The present study is based on an interconnected cluster of nine oilfields in the Central North Sea linked to an onshore CO 2 collection hub by a set of existing and new pipelines. Monte Carlo simulation modelling was undertaken of the prospective returns to investments in CO 2 -EOR in the fields. Relatively high oil prices were employed for the study period (2020–2050) and two contrasting CO 2 transfer price scenarios, the first being the Carbon Price Floor (CPF) introduced by the UK Government and the second being relatively low negotiated prices reflecting recent and prospective levels under the EU-ETS. At CPF prices the investment returns were all found to be negative, but at prices averaging £10 per tonne positive returns were generally achieved. The study emphasises the importance of CO 2 prices and the taxation system in determining the viability of the investments. - Highlights: • Detailed modelling of CO 2 EOR in nine North Sea oil fields. • Overall investment risks are demonstrated to be very high. • Sharing of pipelines in network and cluster of CO 2 -EOR fields significantly reduces investment costs. • Range of plausible CO 2 prices paid by investor results in very wide range of returns from CO 2 -EOR. • CO 2 pricing and tax arrangements for EOR need further attention by policy makers

  15. Brief: Refloating Maureen platform for reuse in waters away from the North Sea

    International Nuclear Information System (INIS)

    Tilling, G.M.

    1996-01-01

    The Maureen platform in the U.K. sector of the North Sea is refloatable by virtue of being a steel, gravity-base structure with large oil storage tanks as legs. The fields producing into the Maureen platform will soon be depleted, and plans are to decommission the platform from its present location. The attractive disposal options all involve refloating the platform as a first step. Of these, reuse of the facility is potentially the most attractive. Once afloat, the platform becomes a towable 110,000-tonne vessel available for use in areas of the world away from the North Sea, with location determined by environmental conditions and water depth. The bulk of the weight (92,000 tonnes) is in the jacket structure; topsides weight is 18,000 tonnes. Subject to detailed tow-route and naval-stability calculations, moving the structure long distances appears to be feasible. This paper discusses the refloating and marine stability of the Maureen oil platform as a vessel under tow. Development and maintenance aspects are presented

  16. Inter-annual variability of North Sea plaice spawning habitat

    Science.gov (United States)

    Loots, C.; Vaz, S.; Koubbi, P.; Planque, B.; Coppin, F.; Verin, Y.

    2010-11-01

    Potential spawning habitat is defined as the area where environmental conditions are suitable for spawning to occur. Spawning adult data from the first quarter (January-March) of the International Bottom Trawl Survey have been used to study the inter-annual variability of the potential spawning habitat of North Sea plaice from 1980 to 2007. Generalised additive models (GAM) were used to create a model that related five environmental variables (depth, bottom temperature and salinity, seabed stress and sediment type) to presence-absence and abundance of spawning adults. Then, the habitat model was applied each year from 1970 to 2007 to predict inter-annual variability of the potential spawning habitat. Predicted responses obtained by GAM for each year were mapped using kriging. A hierarchical classification associated with a correspondence analysis was performed to cluster spawning suitable areas and to determine how they evolved across years. The potential spawning habitat was consistent with historical spawning ground locations described in the literature from eggs surveys. It was also found that the potential spawning habitat varied across years. Suitable areas were located in the southern part of the North Sea and along the eastern coast of England and Scotland in the eighties; they expanded further north from the nineties. Annual survey distributions did not show such northward expansion and remained located in the southern North Sea. This suggests that this species' actual spatial distribution remains stable against changing environmental conditions, and that the potential spawning habitat is not fully occupied. Changes in environmental conditions appear to remain within plaice environmental ranges, meaning that other factors may control the spatial distribution of plaice spawning habitat.

  17. Evidence for a Middle Pleistocene glaciation of MIS 8 age in the southern North Sea

    NARCIS (Netherlands)

    Beets, C.J.

    2005-01-01

    In the coresof borehole 89/2, situated at 541 00 010N and 51 00 040E about 70 km north of the Frisian Islands in the southern North Sea, two diamictonsle vels are found at 770 and 100m below sea floor (i.e. 7110 and 140 below present sea level), respectively. Both diamictonsap pear to be older than

  18. Geology and assessment of undiscovered oil and gas resources of the Northwest Laptev Sea Shelf Province, 2008

    Science.gov (United States)

    Klett, Timothy; Pitman, Janet K.; Moore, Thomas E.; Gautier, Donald L.

    2017-12-22

    The U.S. Geological Survey (USGS) has recently assessed the potential for undiscovered oil and gas resources in the Northwest Laptev Sea Shelf Province as part of the USGS Circum-Arctic Resource Appraisal. The province is in the Russian Arctic, east of Severnaya Zemlya and the Taimyr fold-and-thrust belt. The province is separated from the rest of the Laptev Sea Shelf by the Severnyi transform fault. One assessment unit (AU) was defined for this study: the Northwest Laptev Sea Shelf AU. The estimated mean volumes of undiscovered petroleum resources in the Northwest Laptev Sea Shelf Province are approximately 172 million barrels of crude oil, 4.5 trillion cubic feet of natural gas, and 119 million barrels of natural-gas liquids, north of the Arctic Circle.

  19. Features and application of amino acid oil gelatinizer for controlling oil spills on the sea

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, Hiroyuki

    1987-10-01

    Diffusion of oil spills is prevented and the oil can be easily recovered if it is solidified. Features and application of gelling agent for amino acid series oil are introduced. The gelatinizer for amino acid is made of amino acid derivative with solvent added thereto so that oil can be gelatinized by mere spraying of the agent over oil spills. The agent can be intermixed with oil because it floats on the sea. Oil spill is gelatinized instantly and diffusion of the oils is prevented. The oil can easily be recovered with a fishing net and the like. The influence of oil spills to living aquatic resources is greatly lessened, and the gel is safe for workers. It can gelatinize everything except alcohol. Gelatinization has the depressor effect for volatization and is effective for the prevention of fire. The gelatized oil can be burnt up although it contains 10-20 % of water. Oil film on the water can be completely controlled when the agent is sprayed over it. It contributes to the purification of nature since it is readily decomposed. (1 fig, 4 tabs, 3 refs)

  20. Magnetically tunable oil droplet lens of deep-sea shrimp

    Science.gov (United States)

    Iwasaka, M.; Hirota, N.; Oba, Y.

    2018-05-01

    In this study, the tunable properties of a bio-lens from a deep-sea shrimp were investigated for the first time using magnetic fields. The skin of the shrimp exhibited a brilliantly colored reflection of incident white light. The light reflecting parts and the oil droplets in the shrimp's skin were observed in a glass slide sample cell using a digital microscope that operated in the bore of two superconducting magnets (maximum strengths of 5 and 13 T). In the ventral skin of the shrimp, which contained many oil droplets, some comparatively large oil droplets (50 to 150 μm in diameter) were present. A distinct response to magnetic fields was found in these large oil droplets. Further, the application of the magnetic fields to the sample cell caused a change in the size of the oil droplets. The phenomena observed in this work indicate that the oil droplets of deep sea shrimp can act as lenses in which the optical focusing can be modified via the application of external magnetic fields. The results of this study will make it possible to fabricate bio-inspired soft optical devices in future.

  1. Air-sea exchange fluxes of synthetic polycyclic musks in the North Sea and the Arctic.

    Science.gov (United States)

    Xie, Zhiyong; Ebinghaus, Ralf; Temme, Christian; Heemken, Olaf; Ruck, Wolfgang

    2007-08-15

    Synthetic polycyclic musk fragrances Galaxolide (HHCB) and Tonalide (AHTN) were measured simultaneously in air and seawater in the Arctic and the North Sea and in the rural air of northern Germany. Median concentrations of gas-phase HHCB and AHTN were 4 and 18 pg m(-3) in the Arctic, 28 and 18 pg m(-3) in the North Sea, and 71 and 21 pg m(-3) in northern Germany, respectively. Various ratios of HHCB/AHTN implied that HHCB is quickly removed by atmospheric degradation, while AHTN is relatively persistent in the atmosphere. Dissolved concentrations ranged from 12 to 2030 pg L(-1) for HHCB and from below the method detection limit (3 pg L(-1)) to 965 pg L(-1) for AHTN with median values of 59 and 23 pg L(-1), respectively. The medians of volatilization fluxes for HHCB and AHTN were 27.2 and 14.2 ng m(-2) day(-1) and the depositional fluxes were 5.9 and 3.3 ng m(-2) day(-1), respectively, indicating water-to-air volatilization is a significant process to eliminate HHCB and AHTN from the North Sea. In the Arctic, deposition fluxes dominated the air-sea gas exchange of HHCB and AHTN, suggesting atmospheric input controls the levels of HHCB and AHTN in the polar region.

  2. THE POLLUTION OF THE BOTTOM SEDIMENTSIN THE NORTH-WESTERN PART OF THE CASPIAN SEA HYDROCARBONS AND PERSISTENT ORGANIC POLLUTANTS

    Directory of Open Access Journals (Sweden)

    E. V. Ostrovskaya

    2014-01-01

    Full Text Available Aim. The pollution of the bottom sediments in the north-western part of the Caspian sea hydrocarbons and persistent organic pollutants. Location.Caspian Sea. Methods. The materials for this article is based on the results of monitoring conducted in 2012-2013 years. Results. Sediments in the north-western part of the Caspian Sea as a whole slightly contaminated YV and SOZ, although localized areas of high pollution are marked, especially characteristic of the Middle Caspian. Mainconclusions.The studies were showed, PAY in the sediments are mixed genesis, but most of them, in all probability, were petroleum origin. The not weathered hydrocarbons are presented in sediments, which indicates to the presence of the local sources of the fresh oil pollution on the surveyed area.

  3. Weathering of oils at sea: model/field data comparisons

    International Nuclear Information System (INIS)

    Daling, Per S.; Stroem, Tove

    1999-01-01

    The SINTEF Oil Weathering Model (OWM) has been extensively tested with results from full-scale field trials with experimental oil slicks in the Norwegian NOFO Sea trials in 1994 and 1995 and the AEA 1997 trials in UK. The comparisons between oil weathering values predicted by the model and ground-truth obtained from the field trials are presented and discussed. Good laboratory weathering data of the specific oil as input to the model is essential for obtaining reliable weathering predictions. Predications provided by the SINTEF-OWM enable oil spill personnel to estimate the most appropriate 'window of opportunity' for use of chemical dispersants under various spill situations. Pre-spill scenario analysis with the SINTEF Oil Spill Contingency and Response (OSCAR) model system, in which the SINTEF-OWM is one of several components, has become an important part of contingency plans as well as contingency training of oil spill personnel at refineries, oil terminals and offshore installations in Norway. (Author)

  4. Not normally manned compression platforms for the North Sea

    International Nuclear Information System (INIS)

    Kumaran, K.S.

    1994-01-01

    Gas turbine driven gas compressors have been widely used on manned offshore facilities. Similarly unmanned gas turbine driven compressor stations have been in operation onshore with major gas transmission companies in Europe, North America and elsewhere. This paper summarizes a recent joint industry study to investigate the technical and economic feasibility of Not Normally Manned (NNM) Offshore Compression Facilities in terms of reliability, availability and maintainability. Classification of not normally manned (or unmanned) offshore facilities in the UK North Sea is in accordance with HSE Operations Notice 8. ON8 specifies criteria for offshore visits, visit hours and number of personnel on board for the operation of NNM platforms. This paper describes a typical Southern North Sea gas platform being considered for NNM compressor application. The conclusions from the study was that NNM compression is technically feasible with the facilities being able to provide an availability in excess of 98%. Life cycle costs were of the order of 70% of manned facilities thus significantly improving field development economics

  5. Modelling the atmospheric transport of trace metals from Europe to the North Sea and the Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, G; Weber, H; Grassl, H [GKSS-Forschungszentrum Geesthacht G.m.b.H., Geesthacht-Tesperhude (Germany, F.R.). Inst. fuer Physik

    1989-01-01

    Within the framework of a research contract with the German Federal Environmental Agency the long range transport of trace metals over Europe and the deposition of trace metals into the North Sea and the Baltic Sea are estimated using the EMEP- (European Monitoring and Evaluation Programme) trajectory model. The methodology for the model calculations is explained. Preliminary results for the total deposition of lead into the North Sea and the Baltic Sea show, that the calculated values are lower than previous estimates based on extrapolations from measurements at coastal sites and ship measurements in the southern Baltic Sea, respectively. (orig.).

  6. Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Astrup, Poul; Zhu, Rong

    2016-01-01

    We study the wind climate and its long-term variability in the North Sea and South China Sea, areas relevant for offshore wind energy development, using satellite-based wind data, because very few reliable long-term in-situ sea surface wind observations are available. The Special Sensor Microwave...

  7. Phytoplankton of the North Sea and its dynamics: A review

    Science.gov (United States)

    Reid, P. C.; Lancelot, C.; Gieskes, W. W. C.; Hagmeier, E.; Weichart, G.

    Phytoplankton is the major contributor to algal biomass and primary production of the North Sea, although crops of macroalgae can locally be up to 2000 g C.m -2 along the coast of the U.K. and Norway, and microphytobenthos dominates production in the shallow tidal flat areas bordering the coasts of England, the Netherlands, Germany and Denmark. Data collected since 1932 during the Continuous Plankton Recorder Survey show consistent patterns of geographical, seasonal and annual variation in the distribution of phytoplankton and its major taxonomic components. There is a trend of increased colouration in Recorder silks in the southern North Sea until approximately 1975 since when Colour levels (assumed to be indicative of algal biomass) have declined. In the eutrophic Dutch Wadden Sea the algal crop continued to increase; in Dutch coastal North Sea waters a trend of biomass increase reversed since 1984, apparently due to a reduction in Rhine river outflow. Long-term observations made at Helgoland since the 60's also show trends of increasing nutrients and phytoplankton biomass only to 1984. Adverse effects such as deoxygenation, foam formation and toxin production have been linked to mass concentrations of algae known as blooms. There is no evidence from existing reports for an increase in their frequency, although some years stand out with larger numbers. Occurrence of blooms can partly be explained by hydrographic conditions. More than 30 taxa are recognised as occurring in bloom proportions in the North Sea, approximately one third of which can be toxic. The crop of Bacillariophyceae (diatoms) is not likely to increase with eutrophication due to silicate limitation. An extensive subsurface maximum of armoured dinoflagellates, its abundance gouverned by hydrographic conditions, is the most characteristic feature of the central and northern North Sea in the summer months. Abundance, sometimes dominance, of picoplankton and of species that are not readily detected by

  8. Mutual aid in oil spill response: The Alaskan north slope model

    International Nuclear Information System (INIS)

    McKenzie, B.; Ingram, N.

    1993-01-01

    The Alaskan Arctic Region provides one of the world's most remote and challenging environments in which to mount an oil spill response. To facilitate the timeliness and appropriateness of the response, Alaska Clean Seas (ACS) and the operators of the North Slope oil fields have implemented a mutual aid concept for spill response. The concept is based upon each operator on the North Slope maintaining its own inventory of personnel [a spill response team (SRT)] and equipment that is available on short notice to respond to a spill. If the spill exceeds the responsible operator's resources, additional resources can be obtained from other operators and/or ACS through mutual aid. Individuals from diverse organizations are brought together in a mutual aid event. To allow different organizations to function effectively in a multi-organizational environment, a common management structure was required. The structure chosen for the North Slope was the incident command system (ICS). A key concern when discussing mutual aid is the provision of indemnification from liability for responders. For the North Slope, ACS and its member companies are indemnified when responding to a spill through provisions in the ACS charter and the ACS response action contract

  9. Development of Oil Spill Monitoring System for the Black Sea, Caspian Sea and the Barents/Kara Seas (DEMOSS)

    Science.gov (United States)

    Sandven, Stein; Kudriavtsev, Vladimir; Malinovsky, Vladimir; Stanovoy, Vladimir

    2008-01-01

    DEMOSS will develop and demonstrate elements of a marine oil spill detection and prediction system based on satellite Synthetic Aperture Radar (SAR) and other space data. In addition, models for prediction of sea surface pollution drift will be developed and tested. The project implements field experiments to study the effect of artificial crude oil and oil derivatives films on short wind waves and multi-frequency (Ka-, Ku-, X-, and C-band) dual polarization radar backscatter power and Doppler shift at different wind and wave conditions. On the basis of these and other available experimental data, the present model of short wind waves and radar scattering will be improved and tested.A new approach for detection and quantification of the oil slicks/spills in satellite SAR images is developed that can discriminate human oil spills from biogenic slicks and look-alikes in the SAR images. New SAR images are obtained in coordination with the field experiments to test the detection algorithm. Satellite SAR images from archives as well as from new acquisitions will be analyzed for the Black/Caspian/Kara/Barents seas to investigate oil slicks/spills occurrence statistics.A model for oil spills/slicks transport and evolution is developed and tested in ice-infested arctic seas, including the Caspian Sea. Case studies using the model will be conducted to simulate drift and evolution of oil spill events observed in SAR images. The results of the project will be disseminated via scientific publications and by demonstration to users and agencies working with marine monitoring. The project lasts for two years (2007 - 2009) and is funded under INTAS Thematic Call with ESA 2006.

  10. Sea Ice and Hydrographic Variability in the Northwest North Atlantic

    Science.gov (United States)

    Fenty, I. G.; Heimbach, P.; Wunsch, C. I.

    2010-12-01

    Sea ice anomalies in the Northwest North Atlantic's Labrador Sea are of climatic interest because of known and hypothesized feedbacks with hydrographic anomalies, deep convection/mode water formation, and Northern Hemisphere atmospheric patterns. As greenhouse gas concentrations increase, hydrographic anomalies formed in the Arctic Ocean associated with warming will propagate into the Labrador Sea via the Fram Strait/West Greenland Current and the Canadian Archipelago/Baffin Island Current. Therefore, understanding the dynamical response of sea ice in the basin to hydrographic anomalies is essential for the prediction and interpretation of future high-latitude climate change. Historically, efforts to quantify the link between the observed sea ice and hydrographic variability in the region has been limited due to in situ observation paucity and technical challenges associated with synthesizing ocean and sea ice observations with numerical models. To elaborate the relationship between sea ice and ocean variability, we create three one-year (1992-1993, 1996-1997, 2003-2004) three-dimensional time-varying reconstructions of the ocean and sea ice state in Labrador Sea and Baffin Bay. The reconstructions are syntheses of a regional coupled 32 km ocean-sea ice model with a suite of contemporary in situ and satellite hydrographic and ice data using the adjoint method. The model and data are made consistent, in a least-squares sense, by iteratively adjusting several model control variables (e.g., ocean initial and lateral boundary conditions and the atmospheric state) to minimize an uncertainty-weighted model-data misfit cost function. The reconstructions reveal that the ice pack attains a state of quasi-equilibrium in mid-March (the annual sea ice maximum) in which the total ice-covered area reaches a steady state -ice production and dynamical divergence along the coasts balances dynamical convergence and melt along the pack’s seaward edge. Sea ice advected to the

  11. Prediction of wax buildup in 24 inch cold, deep sea oil loading line

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.; Pitchford, A.C.

    1981-10-01

    When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100 F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.

  12. Neogene dinocyst zonation for the eastern North Sea Basin, Denmark

    DEFF Research Database (Denmark)

    Dybkjær, Karen; Piasecki, Stefan

    2010-01-01

    A dinocyst zonation for the Neogene succession in the eastern part of the North Sea Basin (Denmark) is presented. The zonation is based on an extensive database comprising data from more than fifty onshore and offshore boreholes and about twenty five outcrops. Most of the nineteen dinocyst zones......, of the Lower Miocene, and of the Upper Miocene and Pliocene successions. The previous zonation of the onshore Danish Middle Miocene is reconsidered and partly redefined. The zonation is correlated with other biostratigraphic subdivisions of the Neogene succession in the Danish region in addition to litho...

  13. Fluid substitution studies for North Sea chalk logging data

    DEFF Research Database (Denmark)

    Gommesen, Lars; Mavko, G.; Mukerji, T.

    2002-01-01

    We have tested the application of respectively the Kuster-Toksöz and the Gassmann theory as a tool for predicting pore fluid from the elastic properties of brine-saturated North Sea reservoir chalk. We confirm that the Kuster-Toksöz model predicts a larger fluid effect thant the Gassmann model......, and show that the Kuster-Toksöz model fails to predict the presence of hydrocarbons. The Gassmann prediction for the near and potentially invaded zone corresponds more closely to logging data, than the Gassmann prediction for the far, virgin zone. We hereby conclude that the Gassmann theory predicts...

  14. RKU North Sea. Update on the regional consequence examination concerning the petroleum industry in the North Sea

    International Nuclear Information System (INIS)

    2006-12-01

    An overview over prognoses for oil and gas production and the emissions related to these activities is provided for the years 2005-2025. A description of the Norwegian Continental Shelf's ecosystem, environmental technology employed, and considerations regarding the petroleum industry's effect on the ecosystem are considered. Emissions to air, planned emissions to the sea and accident emissions and spills are treated, as well as other possible environmental effects. Consequences for fishery, cultural monuments and for the society in general are also examined (ml)

  15. Assessment of the environmental status for the North Sea and Baltic Sea

    DEFF Research Database (Denmark)

    Larsen, Martin Mørk; Fryer, Rob; Andersen, Jesper H.

    to or at background”, green for “no harmful effect to the environment” and red for unacceptable. The HELCOM goals set out in the Baltic Sea action plan are similar, “concentrations of hazardous substances close to natural levels”, “all fish safe to eat”, and “healthy wildlife”. The assessment criteria used......The two Conventions for the Baltic Sea (Helsinki, HELCOM) and the North Sea (Oslo-Paris, OSPAR) both are in the process of assessing the state of the marine environment and producing Quality Status reports for their regions for publication in 2010. These assessments will be part of the basis...... for Marine Strategy work in the EU. An overview of the time trends and status for metals, PCBs and PAHs in biota and sediment for the convention areas will be presented, and the scientific basis for the assessments and how results from different contaminant groups and wider areas are aggregated...

  16. Geothermal studies in oil field districts of North China

    Science.gov (United States)

    Wang, Ji-An; Wang, Ji-Yang; Yan, Shu-Zhen; Lu, Xiu-Wen

    In North China, Tertiary sediments give the main oil-genetic series. The mean value of terrestrial heat flow density has been considered to be 60 - 65 mW/m2, and the geothermal gradient in Tertiary sediments usually ranges from 30 to 40° C/km in the region studied. Supposing that the onset of oil generation lies at about 90° C, the upper limit of the depth of oil-generation is at about 2000 to 2500 m depth. Recent paleogeothermal studies using vitrinite reflectance, clay and authigenic minerals, as well as other methods showed that in Eocene the geothermal gradient has been higher than at present. Some results were obtained and discussed.

  17. Formation of Barents Sea Branch Water in the north-eastern Barents Sea

    Directory of Open Access Journals (Sweden)

    Vidar S. Lien

    2013-09-01

    Full Text Available The Barents Sea throughflow accounts for approximately half of the Atlantic Water advection to the Arctic Ocean, while the other half flows through Fram Strait. Within the Barents Sea, the Atlantic Water undergoes considerable modifications before entering the Arctic Ocean through the St. Anna Trough. While the inflow area in the south-western Barents Sea is regularly monitored, oceanographic data from the outflow area to the north-east are very scarce. Here, we use conductivity, temperature and depth data from August/September 2008 to describe in detail the water masses present in the downstream area of the Barents Sea, their spatial distribution and transformations. Both Cold Deep Water, formed locally through winter convection and ice-freezing processes, and Atlantic Water, modified mainly through atmospheric cooling, contribute directly to the Barents Sea Branch Water. As a consequence, it consists of a dense core characterized by a temperature and salinity maximum associated with the Atlantic Water, in addition to the colder, less saline and less dense core commonly referred to as the Barents Sea Branch Water core. The denser core likely constitutes a substantial part of the total flow, and it is more saline and considerably denser than the Fram Strait branch as observed within the St. Anna Trough. Despite the recent warming of the Barents Sea, the Barents Sea Branch Water is denser than observed in the 1990s, and the bottom water observed in the St. Anna Trough matches the potential density at 2000 m depth in the Arctic Ocean.

  18. Effect of pollutant oscillations on oil spreading on the sea

    International Nuclear Information System (INIS)

    Abbey, T.M.; Amakiri, J.O.; Bestman, A.R.

    1997-01-01

    Analytical solutions for oil spreading on the sea are deduced when the pollutant source fluctuates with time for a simple rectangular geometry. Both asymmetrical and symmetrical solutions in the direction perpendicular to the uniform tidal stream are derived. The asymmetrical solution, though ad hoc, sheds light on the necessary adjustment to the simpler symmetric problem. Only a micro computer is necessary to simulate these solutions. (Author)

  19. Current oil and gas production from North American Upper Cretaceous chalks

    Science.gov (United States)

    Scholle, Peter A.

    1977-01-01

    Production of oil and natural gas from North American chalks has increased significantly during the past five years, spurred by the prolific production from North Sea chalks, as well as by higher prices and improved production technology. Chalk reservoirs have been discovered in the Gulf Coast in the Austin Group, Saratoga and Annona Chalks, Ozan Formation, Selma Group, Monroe gas rock (an informal unit of Navarro age), and other Upper Cretaceous units. In the Western Interior, production has been obtained from the Cretaceous Niobrara and Greenhorn Formations. Significant, though subcommercial, discoveries of natural gas and gas condensate also have been made in the Upper Cretaceous Wyandot Formation on the Scotian Shelf of eastern Canada. All North American chalk units share a similar depositional and diagenetic history. The chalks consist primarily of whole and fragmented coccoliths with subordinate planktonic and benthonic Foraminifera, inoceramid prisms, oysters, and other skeletal grains. Most have between 10 and 35 percent HCl-insoluble residue, predominantly clay. Deposition was principally below wave base in tens to hundreds of meters of water. The diagenetic history of a chalk is critical in determining its reservoir potential. All chalk has a stable composition (low-Mg calcite) and very high primary porosity. With subsequent burial, mechanical and chemical (solution-transfer) compaction can reduce or completely eliminate pore space. The degree of loss of primary porosity in chalk sections is normally a direct function of the maximum depth to which it has been buried. Pore-water chemistry, pore-fluid pressures, and tectonic stresses also influence rates of cementation. Oil or gas reservoirs of North American chalk fall into three main groups: 1. Areas with thin overburden and significant primary porosity retention (for example, Niobrara Formation of Kansas and eastern Colorado). 2. Areas with thicker overburden but considerable fracturing. Here primary

  20. Analysis of North Sea Offshore Wind Power Variability

    Directory of Open Access Journals (Sweden)

    Aymeric Buatois

    2014-05-01

    Full Text Available This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind farms, and this total production is analyzed to identify the largest aggregated hourly power variations. Based on publicly available information, a simplified representation of the coastal power grid is built for the countries bordering the North Sea. Wind farms less than 60 km from shore are connected radially to the mainland, while the rest are connected to a hypothetical offshore HVDC (High-Voltage Direct Current power grid, designed such that wind curtailment does not exceed 1% of production. Loads and conventional power plants by technology and associated cost curves are computed for the various national power systems, based on 2030 projections. Using the MATLAB-based MATPOWER toolbox, the hourly optimal power flow for this regional hybrid AC/DC grid is computed for high, low and medium years from the meso-scale database. The largest net load variations are evaluated per market area and related to the extra load-following reserves that may be needed from conventional generators.

  1. In situ flume measurements of resuspension in the North Sea

    Science.gov (United States)

    Thompson, C. E. L.; Couceiro, F.; Fones, G. R.; Helsby, R.; Amos, C. L.; Black, K.; Parker, E. R.; Greenwood, N.; Statham, P. J.; Kelly-Gerreyn, B. A.

    2011-07-01

    The in situ annular flume, Voyager II, was deployed at three sites in the North Sea in order to investigate resuspension events, to determine the physical characteristics of the seabed, to determine the threshold of resuspension of the bed and to quantify erosion rates and erosion depths. These are the first controlled, in situ flume experiments to study resuspension in the North Sea, and were combined with long-term measurements of waves and currents. Resuspension experiments were undertaken at two muddy, and one sandy site: north of the Dogger Bank (DG: water depths ˜80 m, very fine, poorly sorted, very fine-skewed sediment experiencing seasonal thermal stratification of the water column along with oxygen depletion); the Oyster Grounds (OG: ˜40 m, similar bed properties, year round water column thermal stratification, Atlantic forcing); and in the Sean Gas Field (SGF: ˜20 m, moderately sorted, very coarse-skewed sand, and well mixed water column). The erosion thresholds of the bed were found to be 0.66-1.04 Pa (DG) and 0.91-1.27 Pa (OG), with corresponding erosion depths of 0.1-0.15 mm and 0.02-0.06 mm throughout the experiments. Evaluation of a year of current velocities from 2007 indicated that at OG, resuspension of the consolidated bed was limited to on average ˜8% of the time as a result of tidal forcing alone for short (properties of the bed. Therefore, while complex variations in biogeophysical factors affected the critical threshold of erosion, once exceeded, erosion rates were related to the nature of the sediment.

  2. Simulation of an oil film at the sea surface and its radiometric properties in the SWIR

    NARCIS (Netherlands)

    Schwenger, F.; Eijk, A.M.J. van

    2017-01-01

    The knowledge of the optical contrast of an oil layer on the sea under various surface roughness conditions is of great interest for oil slick monitoring techniques. This paper presents a 3D simulation of a dynamic sea surface contaminated by a floating oil film. The simulation considers the damping

  3. The North Atlantic Oscillation: variability and interactions with the North Atlantic ocean and Artic sea ice

    Energy Technology Data Exchange (ETDEWEB)

    Jung, T.

    2000-07-01

    The North Atlantic oscillation (NAO) represents the dominant mode of atmospheric variability in the North Atlantic region and describes the strengthening and weakening of the midlatitude westerlies. In this study, variability of the NAO during wintertime and its relationship to the North Atlantic ocean and Arctic sea ice is investigated. For this purpose, observational data are analyzed along with integrations of models for the Atlantic ocean, Arctic sea ice, and the coupled global climate system. From a statistical point of view, the observed NAO index shows unusually high variance on interdecadal time scales during the 20th century. Variability on other time scales is consistent with realizations of random processes (''white noise''). Recurrence of wintertime NAO anomalies from winter-to-winter with missing signals during the inbetween nonwinter seasons is primarily associated with interdecadal variability of the NAO. This recurrence indicates that low-frequency changes of the NAO during the 20th century were in part externally forced. (orig.)

  4. Morphological response to a North Sea bed depression induced by gas mining

    NARCIS (Netherlands)

    Fluit, C.C.J.M.; Hulscher, Suzanne J.M.H.

    2002-01-01

    Gas mining leads to saucer-like surface depressions. In the North Sea, gas is currently mined at several offshore locations. The associated bed depression has a similar spatial extent as offshore tidal sandbanks, which are large-scale bed patterns covering a significant part of the North Sea bottom.

  5. Diversity and community structure of epibenthic invertebrates and fish in the North Sea

    DEFF Research Database (Denmark)

    Callaway, R.; Alsväg, J.; de Boois, I.

    2002-01-01

    The structure of North Sea benthic invertebrate and fish communities is an important indicator of anthropogenic and environmental impacts. Although North Sea fish stocks are monitored regularly, benthic fauna are not. Here, we report the results of a survey carried out in 2000, in which five...

  6. Modelling thermal stratification in the North Sea: Application of a 2-D potential energy model

    DEFF Research Database (Denmark)

    Nielsen, Morten Holtegaard; St. John, Michael

    2001-01-01

    is forced with wind, dew point temperature from Ekofisk oilfield in the central North Sea, and tidal current and atmospheric radiation. The model is used to simulate the seasonal cycle of stratification in the central North Sea in the years 1988, 1989 and 1990 and is compared to density profiles...

  7. Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

    DEFF Research Database (Denmark)

    Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

    1986-01-01

    Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were co...

  8. Prey selection by North Sea herring (Clupea harengus) with special reference to fish eggs

    NARCIS (Netherlands)

    Segers, F.H.I.D.; Dickey-Collas, M.; Rijnsdorp, A.D.

    2007-01-01

    The herring stock in the North Sea in recent years has recovered to a relatively high biomass, and here we investigate prey selection of individual North Sea herring when population numbers are high. The diet composition, and specifically pelagic fish eggs, was investigated in February 2004. Samples

  9. North Sea mackerel egg survey: dutch participation may and June 2011

    NARCIS (Netherlands)

    Damme, van C.J.G.

    2012-01-01

    Every three years an international North Sea survey is carried out by two European institutes, Institute for Marine Research (IMR) from Norway and Institute for Marine Resources and Ecosystem Studies (IMARES) from the Netherlands, to monitor the spatial and seasonal distribution of North Sea

  10. Micro contaminants in surface sediments and macrobenthic invertebrates of the North Sea

    NARCIS (Netherlands)

    Everaarts, J.M.; Fischer, C.V.

    1989-01-01

    Trace metal concentrations (copper, zinc, cadmium and lead) were measured in the silt fraction (grainsize < 63 µm) of surface sediment of the North Sea. The concentrations varied in different areas of the Dutch continental shelf of the North Sea. The trace metal concentrations were highly related

  11. The Pleistocene reindeer of the North Sea - initial palaeontological data and archaeological remarks

    NARCIS (Netherlands)

    Glimmerveen, J; Mol, D; van der Plicht, H

    The interdisciplinary North Sea Project aims at investigating the biotic history of the Pleistocene in the Southern Bight of the North Sea. Humans were part of these biotopes too as Palaeolithic flint artefacts prove. Based on a large fossil record and radiocarbon dating, it becomes clear that

  12. Quantitative estimation of lithofacies from seismic data in a tertiary turbidite system in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Joerstad, A.K.; Avseth, P.Aa; Mukerji, T.; Mavko, G.; Granli, J.R.

    1998-12-31

    Deep water clastic systems and associated turbidite reservoirs are often characterized by very complex sand distributions and reservoir description based on conventional seismic and well-log stratigraphic analysis may be very uncertain in these depositional environments. There is shown that reservoirs in turbidite systems have been produced very inefficiently in conventional development. More than 70% of the mobile oil is commonly left behind, because of the heterogeneous nature of these reservoirs. In this study there is examined a turbidite system in the North Sea with five available wells and a 3-D seismic near and far offset stack to establish most likely estimates of facies and pore fluid within the cube. 5 figs.

  13. Time-lapse seismic analysis of the North Sea Fulmar Field

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, David H.; McKenny, Robert S.; Burkhart, Tucker D.

    1998-12-31

    Time-lapse seismic analysis has been applied to two 3-D seismic surveys acquired over the central North Sea Fulmar field in a pre-production survey shot in 1977, reprocessed in 1987, and a survey in 1992. The Upper Jurassic reservoirs in the field have been under production since 1982. Differences in averaged impedance between the 1977 and 1992 surveys clearly show the effects of water influx and pressure decline. The changes observed in the seismic data are overall consistent with predictions obtained from a full-field, history-matched simulation. Differences in details may suggest areas of bypassed oil. Dta quality is not sufficient to serve as the sole basis for drilling decisions. 1 ref., 6 figs.

  14. Creating artificial reefs from decommissioned platforms in the North Sea: review of knowledge and proposed programme of research. Vol. 1 of a 2 vol. report. Summary of the main report, with an executive overview

    Energy Technology Data Exchange (ETDEWEB)

    Aabel, Jens Petter; Cripps, Simon; Jensen, Antony; Picken, Gordon

    1997-12-31

    In the continuing debate on the decommissioning and disposal of North Sea oil and gas platforms, the use of redundant structures as artificial reefs remains an untried possibility. It has been suggested that selected, clean, inert steel components could be used to create offshore reefs to attract finfish, to the benefit fisheries and fishermen. This might be an innovative and cost-effective use of these ``materials and opportunity``, and therefore should be examined more fully before the predicted 20-30 year period of steady decommissioning activity in the North Sea begins in earnest. This report relates on reviewing the use and effectiveness of artificial reefs, summarize existing knowledge of the reef effect of North Sea platforms, outline possible scenarios for the creation and exploitation of platform reefs in the North Sea, highlight gaps in knowledge, and to propose programmes of work to study the reef effect at an inshore and an offshore site in the North Sea. 5 tabs.

  15. Creating artificial reefs from decommissioned platforms in the North Sea: review of knowledge and proposed programme of research. Vol. 1 of a 2 vol. report. Summary of the main report, with an executive overview

    Energy Technology Data Exchange (ETDEWEB)

    Aabel, Jens Petter; Cripps, Simon; Jensen, Antony; Picken, Gordon

    1998-12-31

    In the continuing debate on the decommissioning and disposal of North Sea oil and gas platforms, the use of redundant structures as artificial reefs remains an untried possibility. It has been suggested that selected, clean, inert steel components could be used to create offshore reefs to attract finfish, to the benefit fisheries and fishermen. This might be an innovative and cost-effective use of these ``materials and opportunity``, and therefore should be examined more fully before the predicted 20-30 year period of steady decommissioning activity in the North Sea begins in earnest. This report relates on reviewing the use and effectiveness of artificial reefs, summarize existing knowledge of the reef effect of North Sea platforms, outline possible scenarios for the creation and exploitation of platform reefs in the North Sea, highlight gaps in knowledge, and to propose programmes of work to study the reef effect at an inshore and an offshore site in the North Sea. 5 tabs.

  16. Trace elements in a North Sea drill core

    DEFF Research Database (Denmark)

    Kunzendorf, Helmar; Gwozdz, R.; Svendsen, N.

    1986-01-01

    , V, Sr, Dy, Mg, Ti, Ba and Eu. The major elements Ca and Al could be related to petrophysical parameters, particularly Al which shows a correlation with the silicification/argillaceous content. Na (and Cl) has a low content in the hydrocarbon-bearing section of the drill core suggesting that the pore......Chalk samples, systematically taken along a drill core from one of the hydrocarbon producing fields of the North Sea (Tyra field), were analysed by a neutron activation technique involving measurement of radioisotopes with relatively short half-lives. Elements determined include Na, Al, Cl, Ca, Mn...... space is filled mainly by hydrocarbons. A significant decrease of Mn with depth probably suggests diagenesis of chalk prior to, or with, hydrocarbon emplacement. Investigations of drilling fluids and cuttings reveal a strong contamination of the latter, mainly by Ba. Chalk data from comparable onshore...

  17. Subsurface phytoplankton blooms fuel pelagic production in the North Sea

    DEFF Research Database (Denmark)

    Richardson, Kathrine; Visser, Andre; Pedersen, Flemming

    2000-01-01

    The seasonal phytoplankton biomass distribution pattern in stratified temperate marine waters is traditionally depicted as consisting of spring and autumn blooms. The energy source supporting pelagic summer production is believed to be the spring bloom. However, the spring bloom disappears...... relatively quickly from the water column and a large proportion of the material sedimenting to the bottom following the spring bloom is often comprised of intact phytoplankton cells. Thus, it is easy to argue that the spring bloom is fueling the energy demands of the benthos, but more difficult to argue...... convincingly that energy fixed during the spring bloom is fueling the pelagic production occurring during summer months. We argue here that periodic phytoplankton blooms are occurring during the summer in the North Sea at depths of >25 m and that the accumulated new production [sensu (Dugdale and Goering...

  18. Well data summary sheets. Vol. 33: North sea wells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This 33rd volume of the `Well Data Summary sheets` includes data from seven recently released offshore wells from the North Sea. The wells Baron-2, S.E. Adda-1 and Skjold Flank-1 were presented in our `Well Data Summary Sheets, special volume`, published May 1, 1997. In volume 33, the wells Baron-2 and Skjold Flank-1 are updated with respect to information on sidewall cores. Information regarding all released well data, included in our well data summary sheets, are available on GEUS homepage: http://www.geus.dk/ or the departments homepage: http://www.geus.dk/departments/geol-info-data-centre/geoldata.htm/. A complete index of releases wells in volumes 17-33 is included. (au)

  19. Coastal Erosion and Flooding Hazards on the North Sea Coast at Thyboron, Denmark

    DEFF Research Database (Denmark)

    Sørensen, Per; Sørensen, Carlo Sass; Nielsen, Peter

    Since a breach of the coastal barrier in 1862, the Thyboron Channel connecting the North Sea and the Lim Fiord has been artificially maintained by construction of breakwaters and groins on the North Sea coast and inside the channel, respectively. Sand nourishment schemes have since the 1980s coun...... counteracted the natural erosion in the upper profile on the North Sea coast where the alongshore sediment transport converges towards the channel and deposits up to 1 million m3/y on the flood tidal delta inside the fiord, Figure 1.......Since a breach of the coastal barrier in 1862, the Thyboron Channel connecting the North Sea and the Lim Fiord has been artificially maintained by construction of breakwaters and groins on the North Sea coast and inside the channel, respectively. Sand nourishment schemes have since the 1980s...

  20. Impact of Expanded North Slope of Alaska Crude Oil Production on Crude Oil Flows in the Contiguous United States

    Energy Technology Data Exchange (ETDEWEB)

    DeRosa, Sean E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flanagan, Tatiana Paz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    The National Transportation Fuels Model was used to simulate a hypothetical increase in North Slope of Alaska crude oil production. The results show that the magnitude of production utilized depends in part on the ability of crude oil and refined products infrastructure in the contiguous United States to absorb and adjust to the additional supply. Decisions about expanding North Slope production can use the National Transportation Fuels Model take into account the effects on crude oil flows in the contiguous United States.

  1. Potential Impacts of Offshore Wind Farms on North Sea Stratification

    Science.gov (United States)

    Carpenter, Jeffrey R.; Merckelbach, Lucas; Callies, Ulrich; Clark, Suzanna; Gaslikova, Lidia; Baschek, Burkard

    2016-01-01

    Advances in offshore wind farm (OWF) technology have recently led to their construction in coastal waters that are deep enough to be seasonally stratified. As tidal currents move past the OWF foundation structures they generate a turbulent wake that will contribute to a mixing of the stratified water column. In this study we show that the mixing generated in this way may have a significant impact on the large-scale stratification of the German Bight region of the North Sea. This region is chosen as the focus of this study since the planning of OWFs is particularly widespread. Using a combination of idealised modelling and in situ measurements, we provide order-of-magnitude estimates of two important time scales that are key to understanding the impacts of OWFs: (i) a mixing time scale, describing how long a complete mixing of the stratification takes, and (ii) an advective time scale, quantifying for how long a water parcel is expected to undergo enhanced wind farm mixing. The results are especially sensitive to both the drag coefficient and type of foundation structure, as well as the evolution of the pycnocline under enhanced mixing conditions—both of which are not well known. With these limitations in mind, the results show that OWFs could impact the large-scale stratification, but only when they occupy extensive shelf regions. They are expected to have very little impact on large-scale stratification at the current capacity in the North Sea, but the impact could be significant in future large-scale development scenarios. PMID:27513754

  2. Biocorrosive Thermophilic Microbial Communities in Alaskan North Slope Oil Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Kathleen E.; Gieg, Lisa M.; Parisi, Victoria A.; Tanner, Ralph S.; Green Tringe, Susannah; Bristow, Jim; Suflita, Joseph M.

    2009-09-16

    Corrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon, with standard treatment methods targeting mesophilic sulfatereducing bacteria. In assessing biocorrosion potential at an Alaskan North Slope oil field, we identified thermophilic hydrogen-using methanogens, syntrophic bacteria, peptideand amino acid-fermenting bacteria, iron reducers, sulfur/thiosulfate-reducing bacteria and sulfate-reducing archaea. These microbes can stimulate metal corrosion through production of organic acids, CO2, sulfur species, and via hydrogen oxidation and iron reduction, implicating many more types of organisms than are currently targeted. Micromolar quantities of putative anaerobic metabolites of C1-C4 n-alkanes in pipeline fluids were detected, implying that these low molecular weight hydrocarbons, routinely injected into reservoirs for oil recovery purposes, are biodegraded and provide biocorrosive microbial communities with an important source of nutrients.

  3. Coccolithophore assemblage response to Black Sea Water inflow into the North Aegean Sea (NE Mediterranean)

    Science.gov (United States)

    Karatsolis, B.-Th.; Triantaphyllou, M. V.; Dimiza, M. D.; Malinverno, E.; Lagaria, A.; Mara, P.; Archontikis, O.; Psarra, S.

    2017-10-01

    This study aims to presents the species composition of living coccolithophore communities in the NE Aegean Sea, investigating their spatial and temporal variations along a north-south transect in the area receiving the inflowing surface Black Sea Water (BSW) over the deeper Levantine Water (LW) layer. Coccolithophores in the area were relatively diverse and a total of 95 species over 3 sampling periods studied were recognized using Scanning Electron Microscope (SEM) techniques. R-mode hierarchical cluster analysis distinguished two coccolithophore Groups (I, IIa, IIb, IIc) with different ecological preferences. Emiliania huxleyi was the most abundant species of Group I, whereas Syracosphaera spp., Rhabdosphaera spp. and holococcolithophores were prevailing in the highly diversified Group II assemblages. Biometric analysis conducted on E. huxleyi coccoliths from Aegean water column and Black Sea sediment trap samples, indicated that during autumn, NE Aegean specimens in samples under BSW influence were featured by unimodal distribution concerning the coccolith relative tube width, with values similar to those provided by the Black Sea specimens. In early spring, coccoliths in the stations with increased BSW influx displayed a bimodal pattern of relative tube width with smaller values found mostly in the surface layers, while the distribution became again unimodal and dominated by larger values within the deeper LW layers. In the summer period, the typical LW holococcolithophore species (Group II) presented low cell numbers in the surface layer (huxleyi was almost absent in the NE Aegean during the summer sampling period.

  4. Clean-up of the sea bed in the North Sea 1996

    International Nuclear Information System (INIS)

    1997-01-01

    The petroleum activities in the North Sea have inadvertently caused some conflict with fishermen getting their trawls etc. into trash from littering of the sea bed. In the present report, the Norwegian Petroleum Directorate describes a clean-up operation undertaken in 1996 and paid by the State. A clean-up area of 1000 km 2 off Karmoey was selected. This area was mapped by side scan sonar along survey lines 300 m equidistant and a sonar range of 200 m. The sonar data were continuously interpreted by a geophysicist. Selected targets were then identified by ROV and eventually removed. Of the 59 targets examined, 11 were removed and dumped onshore. The largest part elevated was a chain cable of 9 tons. There is also a brief discussion of the compensation agreement with Norwegian fishermen. 4 figs

  5. Sea Spray Aerosol Production over the North Atlantic

    Science.gov (United States)

    Bates, T. S.; Quinn, P.

    2017-12-01

    Breaking waves on the ocean surface generate air bubbles that scavenge organic matter from the surrounding seawater. When injected into the atmosphere, these bubbles burst, yielding sea spray aerosol (SSA), a mixture of organic and inorganic compounds with the organic matter enriched relative to seawater. SSA mass is well documented as the dominant component of aerosol light scattering over the remote oceans. The importance of SSA number to marine boundary layer cloud condensation nuclei (CCN) is much less certain. During the Western Atlantic Climate Study cruises (WACS-1 - August 2012 and WACS-2 - May-June 2014) and the North Atlantic Aerosols and Marine Ecosystem Study cruises (NAAMES-1 - November 2015, NAAMES-2 - May 2016, and NAAMES-3 - September 2017), we generated and measured freshly emitted SSA using the Sea Sweep SSA generator. During the 2017 cruise we also generated SSA with a Marine Aerosol Reference Tank (MART). Using the data generated on these 5 cruises and a large database of remote marine boundary layer aerosol measurements we will address three questions during this presentation: 1 - Do phytoplankton ecosystems affect the organic enrichment of freshly emitted SSA?, 2 - Do plankton ecosystems affect the number production flux of SSA?, and 3 - Is SSA a significant source of atmospheric CCN?

  6. UK North Sea Strathspey Field development: How use of a satellite tie-back to a third party host created a ''win-win'' situation

    International Nuclear Information System (INIS)

    Cheifetz, S.A.; Hale, J.E.

    1994-01-01

    The Texaco operated Strathspey Field lies in the Northern Sector of the UK North Sea. Development options for the 150 million barrel oil equivalent field included use of a fixed platform, floating production system and sub-sea tieback to an existing platform. Decision Analysis was used to examine the risk profile of the different options. The choice of a subsea tieback to the Chevron operated Ninian Field (North ampersand South Platforms) created economic benefits for partners in both fields as compared to the use of a stand-alone development for Strathspey

  7. Impact of North Atlantic Current changes on the Nordic Seas and the Arctic Ocean

    OpenAIRE

    Kauker, Frank; Gerdes, Rüdiger; Karcher, Michael; Köberle, Cornelia

    2005-01-01

    The impact of North Atlantic Current (NAC) volume, heat, and salt transport variability onto the NordicSeas and the Arctic Ocean is investigated using numerical hindcast and sensitivity experiments. Theocean-sea ice model reproduces observed propagation pathways and speeds of SST anomalies.Part of the signal reaching the entrance to the Nordic Seas between Iceland and Scotland originatesin the lower latitude North Atlantic. Response experiments with different prescribed conditionsat 50N show ...

  8. Transport and hydraulically-induced recycling of phosphorous in the North Sea-Baltic Sea transition zone

    DEFF Research Database (Denmark)

    Kepp, Rikke; Struve, Anke; Christiansen, Christian

    2006-01-01

    to barotropic and tidal currents the gross transport is 5 times larger. The net transport is directed towards the North Sea mainly in the top 32 m of the water column but towards the Baltic Sea it occurs in the lower 5 m of the water column. The resulting transport of phosphorus is strongly affected by vertical...

  9. Land-sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

    NARCIS (Netherlands)

    Donders, Timme; Van Helmond, Niels A.G.M.; Verreussel, Roel; Munsterman, Dirk; Veen, Johan Ten; Speijer, Robert P.; Weijers, Johan W.H.; Sangiorgi, Francesca; Peterse, Francien; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.; Lourens, Lucas; Kuhlmann, Gesa; Brinkhuis, Henk

    2018-01-01

    We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (ĝ1/4 2.6-1.8ĝ€Ma) multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of

  10. An Ichthyophonus hoferi epizootic in herring in the North Sea, the Skagerrak, the Kattegat and the Baltic Sea

    DEFF Research Database (Denmark)

    Mellergaard, Stig; Spanggaard, Bettina

    1997-01-01

    An epizootic caused by the internal parasite Ichthyophonus hoferi in herring Clupea harengus was recorded from 1991 to 1993 in the waters around Denmark. A surveillance programme from research vessels and commercial fishing boats was conducted in the North Sea, Skagerrak, Kattegat and Baltic Sea...

  11. Bioaccumulation of petroleum hydrocarbons in arctic amphipods in the oil development area of the Alaskan Beaufort Sea.

    Science.gov (United States)

    Neff, Jerry M; Durell, Gregory S

    2012-04-01

    An objective of a multiyear monitoring program, sponsored by the US Department of the Interior, Bureau of Ocean Energy Management was to examine temporal and spatial changes in chemical and biological characteristics of the Arctic marine environment resulting from offshore oil exploration and development activities in the development area of the Alaskan Beaufort Sea. To determine if petroleum hydrocarbons from offshore oil operations are entering the Beaufort Sea food web, we measured concentrations of hydrocarbons in tissues of amphipods, Anonyx nugax, sediments, Northstar crude oil, and coastal peat, collected between 1999 and 2006 throughout the development area. Mean concentrations of polycyclic aromatic hydrocarbons (PAH), saturated hydrocarbons (SHC), and sterane and triterpane petroleum biomarkers (StTr) were not significantly different in amphipods near the Northstar oil production facility, before and after it came on line in 2001, and in amphipods from elsewhere in the study area. Forensic analysis of the profiles (relative composition and concentrations) of the 3 hydrocarbon classes revealed that hydrocarbon compositions were different in amphipods, surface sediments where the amphipods were collected, Northstar crude oil, and peat from the deltas of 4 North Slope rivers. Amphipods and sediments contained a mixture of petrogenic, pyrogenic, and biogenic PAH. The SHC in amphipods were dominated by pristane derived from zooplankton, indicating that the SHC were primarily from the amphipod diet of zooplankton detritus. The petroleum biomarker StTr profiles did not resemble those in Northstar crude oil. The forensic analysis revealed that hydrocarbons in amphipod tissues were not from oil production at Northstar. Hydrocarbons in amphipod tissues were primarily from their diet and from river runoff and coastal erosion of natural diagenic and fossil terrestrial materials, including seep oils, kerogens, and peat. Offshore oil and gas exploration and development

  12. Satellite observations and modeling of oil spill trajectories in the Bohai Sea

    DEFF Research Database (Denmark)

    Xu, Qing; Li, Xiaofeng; Wei, Yongliang

    2013-01-01

    On June 4 and 17, 2011, separate oil spill accidents occurred at two oil platforms in the Bohai Sea, China. The oil spills were subsequently observed on different types of satellite images including SAR (Synthetic Aperture Radar), Chinese HJ-1-B CCD and NASA MODIS. To illustrate the fate of the oil...

  13. Oil spills in open seas and harbours - impact on marine environment

    International Nuclear Information System (INIS)

    Siddiqui, S.H.

    1995-01-01

    In this article the environmental impacts of sea water near Karachi (Pakistan) harbour (Arabian Sea) are discussed. The water pollution is caused due to oil leakage from ships. The toxicity of various oils (crude oils and refined oils) to different species of marine varies greatly. The second main source of water is municipal waste water. For the control of sea water pollution, there must be education as lack of awareness of the public to ask for clean beaches and absence of coordination between concerned oil companies, tanker operating agencies, port authorities and government (A.B.)

  14. Simulation of an oil film at the sea surface and its radiometric properties in the SWIR

    Science.gov (United States)

    Schwenger, Frédéric; Van Eijk, Alexander M. J.

    2017-10-01

    The knowledge of the optical contrast of an oil layer on the sea under various surface roughness conditions is of great interest for oil slick monitoring techniques. This paper presents a 3D simulation of a dynamic sea surface contaminated by a floating oil film. The simulation considers the damping influence of oil on the ocean waves and its physical properties. It calculates the radiance contrast of the sea surface polluted by the oil film in relation to a clean sea surface for the SWIR spectral band. Our computer simulation combines the 3D simulation of a maritime scene (open clear sea/clear sky) with an oil film at the sea surface. The basic geometry of a clean sea surface is modeled by a composition of smooth wind driven gravity waves. Oil on the sea surface attenuates the capillary and short gravity waves modulating the wave power density spectrum of these waves. The radiance of the maritime scene is calculated in the SWIR spectral band with the emitted sea surface radiance and the specularly reflected sky radiance as components. Wave hiding and shadowing, especially occurring at low viewing angles, are considered. The specular reflection of the sky radiance at the clean sea surface is modeled by an analytical statistical bidirectional reflectance distribution function (BRDF) of the sea surface. For oil at the sea surface, a specific BRDF is used influenced by the reduced surface roughness, i.e., the modulated wave density spectrum. The radiance contrast of an oil film in relation to the clean sea surface is calculated for different viewing angles, wind speeds, and oil types characterized by their specific physical properties.

  15. State of oil pollution in the northern Arabian Sea after the 1991 Gulf oil spill

    Digital Repository Service at National Institute of Oceanography (India)

    Sengupta, R.; Fondekar, S.P.; Alagarsamy, R.

    stream_size 30182 stream_content_type text/plain stream_name Mar_Pollut_Bull_27_85.pdf.txt stream_source_info Mar_Pollut_Bull_27_85.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Marine Pollution... Bulletin, Volume 27, pp. 85-91, 1993. 0025-326X/93 $6.00+0.00 Printed in Great Britain. O 1993 Pergamon Press Ltd State of Oil Pollution in the Northern Arabian Sea after the 1991 Gulf Oil Spill R. SEN GUPTA, S. P. FONDEKAR and R. ALAGARSAMY National...

  16. Oil spill hazard assessment using a reverse trajectory method for the Egadi marine protected area (Central Mediterranean Sea).

    Science.gov (United States)

    Ciappa, Achille; Costabile, Salvatore

    2014-07-15

    The Egadi Marine Protected Area (MPA) on the western side of the Sicily Channel (Central Mediterranean) is exposed to a high risk of oil pollution from the tanker routes connecting the eastern and western basins of the Mediterranean Sea. Areas where an oil spill would do most damage, and thus where surveillance should be concentrated, are identified in this study by Lagrangian tracers tracked backwards in time from points along the MPA perimeter using data spanning six years from 2006 to 2011. Results indicate that the areas where oil surveillance would be most beneficial are segments of the tanker routes south of Sicily (highly frequented) and north of Sicily (scarcely frequented), both extending about 150 miles from November to March and 100 miles in the other months. The third route, close to the Tunisian shore, is the most frequented by oil tankers but the threat period is limited to November and December. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Changes in size and trends of North American sea duck populations associated with North Pacific oceanic regime shifts

    Science.gov (United States)

    Flint, Paul L.

    2013-01-01

    Broad-scale multi-species declines in populations of North American sea ducks for unknown reasons is cause for management concern. Oceanic regime shifts have been associated with rapid changes in ecosystem structure of the North Pacific and Bering Sea. However, relatively little is known about potential effects of these changes in oceanic conditions on marine bird populations at broad scales. I examined changes in North American breeding populations of sea ducks from 1957 to 2011 in relation to potential oceanic regime shifts in the North Pacific in 1977, 1989, and 1998. There was strong support for population-level effects of regime shifts in 1977 and 1989, but little support for an effect of the 1998 shift. The continental-level effects of these regime shifts differed across species groups and time. Based on patterns of sea duck population dynamics associated with regime shifts, it is unclear if the mechanism of change relates to survival or reproduction. Results of this analysis support the hypothesis that population size and trends of North American sea ducks are strongly influenced by oceanic conditions. The perceived population declines appear to have halted >20 years ago, and populations have been relatively stable or increasing since that time. Given these results, we should reasonably expect dramatic changes in sea duck population status and trends with future oceanic regime shifts.

  18. An Ichthyophonus hoferi epizootic in herring in the North Sea, the Skagerrak, the Kattegat and the Baltic Sea

    OpenAIRE

    Mellergaard, Stig; Spanggaard, Bettina

    1997-01-01

    An epizootic caused by the internal parasite Ichthyophonus hoferi in herring Clupea harengus was recorded from 1991 to 1993 in the waters around Denmark. A surveillance programme from research vessels and commercial fishing boats was conducted in the North Sea, Skagerrak, Kattegat and Baltic Sea. A total of 15769 hearts of adult herring were examined macroscopically for evidence of infection. The prevalence of the infection in this period decreased from 10.6 to 2.0% in the North Sea, from 8.0...

  19. Climate change facilitated range expansion of the non-native angular crab Goneplax rhomboides into the North Sea

    NARCIS (Netherlands)

    Neumann, H.; Boois, de I.J.; Kroncke, I.; Reiss, H.

    2013-01-01

    The angular crab Goneplax rhomboides is native to the north-eastern Atlantic and Mediterranean Sea. It has rarely been reported from the North Sea, with no evidence of sustainable populations. Compiled survey data, however, revealed an increasing abundance of this species in the North Sea since

  20. What Causes the North Sea Level to Rise Faster over the Last Decade ?

    Science.gov (United States)

    Karpytchev, Mikhail; Letetrel, Camille

    2013-04-01

    We combined tide gauge records (PSMSL) and satellite altimetry data (TOPEX/POSEIDON-JASON 1-2) to reconstruct the mean level of the North Sea and the Norwegian Sea Shelf (NS-NSS) over 1950-2012. The reconstructed NS-NSS mean sea level fluctuations reveal a pronounced interannual variability and a strong sea level acceleration since the mid-1990's. In order to understand the causes of this acceleration, the NS-NSS mean sea level was cross-correlated with the North Atlantic Oscillation and Arctic Oscillation indices. While the interannual variability of the mean sea level correlates well with the NAO/AO indices, the observed acceleration in the NS-NSS mean level is not linked linearly to the NAO/AO fluctuations. On the other hand, the Empirical Orthogonal Functions (EOF) analysis of steric sea level variations in the eastern North Atlantic gives a dominant EOF pattern (55% of variance explained) that varies on a decadal scale very closely to the NS-NSS mean level flcutuations. Also, the amplification in the temporal amplitude of the dominant steric sea level EOF corresponds to the acceleration observed in the NS-NSS mean sea level signal. This suggests that decadal variations in the mean level of the North Sea - the Norwegian Sea Shelf reflect changes in the Subpolar Front currents (Rossby, 1996).

  1. Towards uncertainty estimation for operational forecast products - a multi-model-ensemble approach for the North Sea and the Baltic Sea

    Science.gov (United States)

    Golbeck, Inga; Li, Xin; Janssen, Frank

    2014-05-01

    Several independent operational ocean models provide forecasts of the ocean state (e.g. sea level, temperature, salinity and ice cover) in the North Sea and the Baltic Sea on a daily basis. These forecasts are the primary source of information for a variety of information and emergency response systems used e.g. to issue sea level warnings or carry out oil drift forecast. The forecasts are of course highly valuable as such, but often suffer from a lack of information on their uncertainty. With the aim of augmenting the existing operational ocean forecasts in the North Sea and the Baltic Sea by a measure of uncertainty a multi-model-ensemble (MME) system for sea surface temperature (SST), sea surface salinity (SSS) and water transports has been set up in the framework of the MyOcean-2 project. Members of MyOcean-2, the NOOS² and HIROMB/BOOS³ communities provide 48h-forecasts serving as inputs. Different variables are processed separately due to their different physical characteristics. Based on the so far collected daily MME products of SST and SSS, a statistical method, Empirical Orthogonal Function (EOF) analysis is applied to assess their spatial and temporal variability. For sea surface currents, progressive vector diagrams at specific points are consulted to estimate the performance of the circulation models especially in hydrodynamic important areas, e.g. inflow/outflow of the Baltic Sea, Norwegian trench and English Channel. For further versions of the MME system, it is planned to extend the MME to other variables like e.g. sea level, ocean currents or ice cover based on the needs of the model providers and their customers. It is also planned to include in-situ data to augment the uncertainty information and for validation purposes. Additionally, weighting methods will be implemented into the MME system to develop more complex uncertainty measures. The methodology used to create the MME will be outlined and different ensemble products will be presented. In

  2. Biomarkers reveal sea turtles remained in oiled areas following the Deepwater Horizon oil spill

    Science.gov (United States)

    Vander Zanden, Hannah B.; Bolten, Alan B.; Tucker, Anton D.; Hart, Kristen M.; Lamont, Margaret M.; Fujisaki, Ikuko; Reich, Kimberly J.; Addison, David S.; Mansfield, Katherine L.; Phillips, Katrina F.; Pajuelo, Mariela; Bjorndal, Karen A.

    2016-01-01

    Assessments of large-scale disasters, such as the Deepwater Horizon oil spill, are problematic because while measurements of post-disturbance conditions are common, measurements of pre-disturbance baselines are only rarely available. Without adequate observations of pre-disaster organismal and environmental conditions, it is impossible to assess the impact of such catastrophes on animal populations and ecological communities. Here, we use long-term biological tissue records to provide pre-disaster data for a vulnerable marine organism. Keratin samples from the carapace of loggerhead sea turtles record the foraging history for up to 18 years, allowing us to evaluate the effect of the oil spill on sea turtle foraging patterns. Samples were collected from 76 satellite-tracked adult loggerheads in 2011 and 2012, approximately one to two years after the spill. Of the 10 individuals that foraged in areas exposed to surface oil, none demonstrated significant changes in foraging patterns post spill. The observed long-term fidelity to foraging sites indicates that loggerheads in the northern Gulf of Mexico likely remained in established foraging sites, regardless of the introduction of oil and chemical dispersants. More research is needed to address potential long-term health consequences to turtles in this region. Mobile marine organisms present challenges for researchers to monitor effects of environmental disasters, both spatially and temporally. We demonstrate that biological tissues can reveal long-term histories of animal behavior and provide critical pre-disaster baselines following an anthropogenic disturbance or natural disaster.

  3. Creating artificial reefs from decommissioned platforms in the North Sea: review of knowledge and proposed programme of research

    Energy Technology Data Exchange (ETDEWEB)

    Aabel, J.P.; Cripps, S.J.; Jensen, A.C.; Picken, G.

    1997-12-31

    This report relates to the case for research and development work on North Sea artificial reefs. There are potentially many benefits that can be derived from platform reefs, for example as an aid to increased fishing yield for commercial fishermen, a means of enhancing fish stocks and protecting habitat for physical damage. In addition there may be a reduction in decommissioning costs for the oil industry and in negative environmental impacts inherent with land-based decommissioning techniques. Negative impacts could be loss of fishing area and changes in the ecosystem. The report will be focused towards practically applicable results that will aid the decision making process. 129 refs., 13 figs., 18 tabs.

  4. Creating artificial reefs from decommissioned platforms in the North Sea: review of knowledge and proposed programme of research

    Energy Technology Data Exchange (ETDEWEB)

    Aabel, J P; Cripps, S J; Jensen, A C; Picken, G

    1998-12-31

    This report relates to the case for research and development work on North Sea artificial reefs. There are potentially many benefits that can be derived from platform reefs, for example as an aid to increased fishing yield for commercial fishermen, a means of enhancing fish stocks and protecting habitat for physical damage. In addition there may be a reduction in decommissioning costs for the oil industry and in negative environmental impacts inherent with land-based decommissioning techniques. Negative impacts could be loss of fishing area and changes in the ecosystem. The report will be focused towards practically applicable results that will aid the decision making process. 129 refs., 13 figs., 18 tabs.

  5. Differentiation of Palaeogene sand by glauconitic and geochemical fingerprinting, Siri Canyon, Danish North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Olivarius, M.; Knudsen, Christian; Svendsen, Johan B.

    2011-07-01

    The submarine Siri Canyon is NE-SW-oriented and located in the Danish North Sea. It contains a number of oil reservoirs with glauconite-rich sand. The reservoirs of interest in the Nini oil field are the Late Paleocene Tyr Member of the Lista Formation and the Kolga Member of the Sele Formation, presumably of Early Eocene age. These members have previously been known as the Ty and Hermod members. The sand shows signs of injection, both in cores and in seismic data. The aim of this work is to chemically characterise and fingerprint the sand in order to reveal the origin of the sand found in three horizontal wells, which could have been injected from one or both of the Tyr and Kolga members. Core samples were collected from two vertical wells of known stratigraphy to make a basis of comparison, whereas samples of the cuttings were collected from the three horizontal wells with ages primarily corresponding to the Kolga Member. The purpose was moreover to evaluate whether cuttings samples can be used for fingerprinting as an alternative to core samples. The interest in discriminating between the ages of the injected sand is the fact that the reservoir properties (porosity and permeability) are largely controlled by the original composition of the sand. Consequently, results from this study could affect the property modelling of the field. (LN)

  6. Assessment of oil pollution as consequence of the oil leaks from seabed pipeline in the Bohai Sea

    International Nuclear Information System (INIS)

    Wang, J.; Li, X.; Goncharov, V.K.; Klementieva, N.Y.

    2005-01-01

    Although oil leaks from pipelines are less dangerous than a blowout of oil as a result of a pipeline break, the presence of oil in the ocean can have a devastating affect on the marine environment, particularly as oil leaks are difficult to detect and can occur over long periods of time. This paper discussed oil pollution in the Bohai Sea. Most of the crude oil in the Bohai oil fields is heavy and contains both paraffin and sand, both of which contribute to greater incidences of cracks and corrosion wormholes in pipes. The Main Points of Model for Assessment of Environmental Consequence of the Oil Leaks from Marine Pipeline (MAECOLMP) is based on the assumption that oil leaks from wormholes on seabed pipelines generate separate oil drops which float up to create a plume in the water. After their emergence on the sea surface, an oil slick forms, which has the shape of a serpentine strip extending along the surface in the direction of the current. The main parameters that define environmental oil pollution are: the dimensions of oil drops in the water; the dimension of the oil slick on the sea surface; and the carryover of crude oil on the coastline. According to the model, the assessment of environmental effects of the oil leaks from the sea bed consist of the following stages: selection of the probable position of wormholes in the pipeline and their size; calculation of the rate of the oil leak from the wormhole for selected sizes and positions; estimation of probable average sizes of oil drops for the selected diameter of wormhole; calculation of boundaries of the plume; calculation of the width and extension of the oil slicks for each selected position of the wormhole; and estimation of the volume of crude oil that can be carried over to the coastline in each case and detection of the most dangerous accident variant. This model permits the use of the Lagrangian description in order to take into account the difference in the velocities of emerging oil drops. It

  7. Distributions of freak wave heights measured in the North Sea

    International Nuclear Information System (INIS)

    Stansell, P.

    2004-01-01

    We present a statistical analysis of some of the largest waves occurring during 793 h of surface elevation measurements collected during 14 severe storms in the North Sea. This data contains 104 freak waves. It is found that the probability of occurrence of freak waves is only weekly dependent on the significant wave height, significant wave steepness and spectral bandwidth. The probability does show a slightly stronger dependency on the skew and kurtosis of the surface elevation data, but on removing the contribution to these measures from the presence of the freakwaves themselves, this dependency largely disappears. Distributions of extreme waves are modelled by fitting Generalised Pareto distributions, and extreme value distributions and return periods are given for freak waves in terms of the empirical fitted parameters. It is shown by comparison with these fits that both the Rayleigh distribution and the fit of Nerzic and Prevosto severely under-predict the probability of occurrence of extreme waves. For the most extreme freak wave in our data, the Rayleigh distribution over-predicts the return period by about 300 times when compared to the fitted model. (author)

  8. Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

    Science.gov (United States)

    Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

    2016-04-01

    In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

  9. The effects of the Sea Empress oil spill on the plankton of the southern Irish Sea

    International Nuclear Information System (INIS)

    Batten, S.; Allen, R.; Wotton, C.

    1997-07-01

    This report describes the methodology used to determine any effects of the Sea Empress oil spill on the plankton communities of the southern Irish Sea. The Continuous Plankton Recorder (CPR) survey has monitored the plankton in this area since 1970 so there is a long time series of data collected before the spill, almost 2000 samples, with which to compare the post-spill data. The analytical procedures applied and results obtained are presented and reveal that in the majority of cases no significant effects were evident. Some exceptions are also described. The results suggest that no further analysis of the plankton communities is necessary, unless other studies reveal that other marine habitats which may have an influence on the plankton of this area are continuing to display effects of the spill. There is scope for further investigation of the trends and events described in this report but this is outside the remit of the project. (author)

  10. Spatial differences in growth of lesser sandeel in the North Sea

    DEFF Research Database (Denmark)

    Rindorf, Anna; Wright, Peter J.; Jensen, Henrik

    2016-01-01

    Lesser sandeel, Ammodytes marinus, is a key prey to a variety of North Sea predators, including species such as single load seabirds which are highly sensitive to prey size and condition. Whilst differences in weight at age across the North Sea have been investigated previously, the scale and cause...... of this variation as well as the potential link to spatial differences in predator performance remains unknown. This study presents an analysis of spatial patterns in length and condition of the lesser sandeel in the North Sea and the relationship of these with physical and biological factors. Both mean length...... considerably both spatially and temporally, resulting in 4 fold and 1.9 fold variations in the number of sandeels required to obtain a specific weight, respectively. Hence, the value of sandeel as prey to single load predators varies considerably with values in central and northeastern North Sea being...

  11. Evaluating environmental effects of oil spills by simulating the behaviour and spreading of oil on the sea surface

    International Nuclear Information System (INIS)

    Goncharov, V.K.; Ivanov, I.V.; Sokolov, A.N.

    2005-01-01

    The area of polluted surface of the sea and the volume of crude oil carried to the coastline are the main parameters that determine ecological damage. This paper considered some of the problems surrounding the assessment of environmental impacts caused by oil spills in the marine environment. Assessment of potential damage involves the analysis of many possible scenarios and the conditions that accompany them, including varying weather conditions. Computer simulations of the behaviour of spilled oil on the sea surface along with other criteria allow for the evaluation of the predicted scenario. Computer simulations provide knowledge of the spreading and drift of oil, as well as its volume and thickness. Knowledge of the following factors, combined with a knowledge of weather conditions is important in emergency response planning: vulnerability of oil pollution areas on shore; calculation of impact factors; detection of vulnerability to oil pollution; the possibility of incidents of the inadmissible oil pollution forecast; and results of a simulation of 48 hour drift of oil slick formed due to a spill in Devkin Zavod Bay. Adequate meteorological information is crucial for the development of valid data. Further progress is currently being developed for specific water areas around oil fields, tanker routes, seabed crude oil pipeline, wind currents, heaving, hydrological and environmental characteristics of sea water. 5 refs., 3 figs

  12. Sea level anomaly in the North Atlantic and seas around Europe: Long-term variability and response to North Atlantic teleconnection patterns.

    Science.gov (United States)

    Iglesias, Isabel; Lorenzo, M Nieves; Lázaro, Clara; Fernandes, M Joana; Bastos, Luísa

    2017-12-31

    Sea level anomaly (SLA), provided globally by satellite altimetry, is considered a valuable proxy for detecting long-term changes of the global ocean, as well as short-term and annual variations. In this manuscript, monthly sea level anomaly grids for the period 1993-2013 are used to characterise the North Atlantic Ocean variability at inter-annual timescales and its response to the North Atlantic main patterns of atmospheric circulation variability (North Atlantic Oscillation, Eastern Atlantic, Eastern Atlantic/Western Russia, Scandinavian and Polar/Eurasia) and main driven factors as sea level pressure, sea surface temperature and wind fields. SLA variability and long-term trends are analysed for the North Atlantic Ocean and several sub-regions (North, Baltic and Mediterranean and Black seas, Bay of Biscay extended to the west coast of the Iberian Peninsula, and the northern North Atlantic Ocean), depicting the SLA fluctuations at basin and sub-basin scales, aiming at representing the regions of maximum sea level variability. A significant correlation between SLA and the different phases of the teleconnection patterns due to the generated winds, sea level pressure and sea surface temperature anomalies, with a strong variability on temporal and spatial scales, has been identified. Long-term analysis reveals the existence of non-stationary inter-annual SLA fluctuations in terms of the temporal scale. Spectral density analysis has shown the existence of long-period signals in the SLA inter-annual component, with periods of ~10, 5, 4 and 2years, depending on the analysed sub-region. Also, a non-uniform increase in sea level since 1993 is identified for all sub-regions, with trend values between 2.05mm/year, for the Bay of Biscay region, and 3.98mm/year for the Baltic Sea (no GIA correction considered). The obtained results demonstrated a strong link between the atmospheric patterns and SLA, as well as strong long-period fluctuations of this variable in spatial and

  13. Exporting Alaskan North Slope crude oil: Benefits and costs

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Department of Energy study examines the effects of lifting the current prohibitions against the export of Alaskan North Slope (ANS) crude. The study concludes that permitting exports would benefit the US economy. First, lifting the ban would expand the markets in which ANS oil can be sold, thereby increasing its value. ANS oil producers, the States of California and Alaska, and some of their local governments all would benefit from increased revenues. Permitting exports also would generate new economic activity and employment in California and Alaska. The study concludes that these economic benefits would be achieved without increasing gasoline prices (either in California or in the nation as a whole). Lifting the export ban could have important implications for US maritime interests. The Merchant Marine Act of 1970 (known as the Jones Act) requires all inter-coastal shipments to be carried on vessels that are US-owned, US-crewed, and US-built. By limiting the shipment of ANS crude to US ports only, the export ban creates jobs for the seafarers and the builders of Jones Act vessels. Because the Jones Act does not apply to exports, however, lifting the ban without also changing US maritime law would jeopardize the jobs associated with the current fleet of Jones Act tankers. Therefore the report analyzes selected economic impacts of several maritime policy alternatives, including: Maintaining current law, which allows foreign tankers to carry oil where export is allowed; requiring exports of ANS crude to be carried on Jones Act vessels; and requiring exports of ANS crude to be carried on vessels that are US-owned and US-crewed, but not necessarily US-built. Under each of these options, lifting the export ban would generate economic benefits.

  14. Exporting Alaskan North Slope crude oil: Benefits and costs

    International Nuclear Information System (INIS)

    1994-06-01

    The Department of Energy study examines the effects of lifting the current prohibitions against the export of Alaskan North Slope (ANS) crude. The study concludes that permitting exports would benefit the US economy. First, lifting the ban would expand the markets in which ANS oil can be sold, thereby increasing its value. ANS oil producers, the States of California and Alaska, and some of their local governments all would benefit from increased revenues. Permitting exports also would generate new economic activity and employment in California and Alaska. The study concludes that these economic benefits would be achieved without increasing gasoline prices (either in California or in the nation as a whole). Lifting the export ban could have important implications for US maritime interests. The Merchant Marine Act of 1970 (known as the Jones Act) requires all inter-coastal shipments to be carried on vessels that are US-owned, US-crewed, and US-built. By limiting the shipment of ANS crude to US ports only, the export ban creates jobs for the seafarers and the builders of Jones Act vessels. Because the Jones Act does not apply to exports, however, lifting the ban without also changing US maritime law would jeopardize the jobs associated with the current fleet of Jones Act tankers. Therefore the report analyzes selected economic impacts of several maritime policy alternatives, including: Maintaining current law, which allows foreign tankers to carry oil where export is allowed; requiring exports of ANS crude to be carried on Jones Act vessels; and requiring exports of ANS crude to be carried on vessels that are US-owned and US-crewed, but not necessarily US-built. Under each of these options, lifting the export ban would generate economic benefits

  15. Dispersion of radionuclides in the European north-western seas: observations and modelling

    International Nuclear Information System (INIS)

    Bailly du Bois, Pascal

    2013-01-01

    In this report for an Accreditation to supervise research (HDR), the author reports the use over 30 years by the Cherbourg-Octeville IRSN Laboratory of artificial radionuclides in solution in sea water as oceanographic markers. Such measurements on radio-markers which are soluble in sea water, enabled a better knowledge of dissolved substance displacements in north-western seas of Europe, notably the Channel, the North Sea, the Celtic Sea, and the Irish Sea. The author reports researches which aimed at studying the dispersion of radionuclides in seawater and their use as water mass markers, at validating hydrodynamic models of dispersion at different time-space scales, at the understanding and simulation of the sedimentary transport, and at studying the transfer to living species. These different topics give the document its structure [fr

  16. Chemical and temperature profile data from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean (NODC Accession 9700022)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical and temperature profile data were collected from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean. Data were submitted by the Japan...

  17. Transport, preservation and accumulation of organic carbon in the North Sea

    NARCIS (Netherlands)

    Haas, H. de

    1997-01-01

    This thesis contains the results of the research on the burial of organic carbon in the North Sea as it was carried out at the Netherlands Institute for Sea Research in the period 1993-1997. Carbon in the form of carbon dioxide (C02 ) is one of the major contributors to the natural greenhouse

  18. Transport, preservation and accumulation of organic carbon in the North Sea

    NARCIS (Netherlands)

    de Haas, H.

    1997-01-01

    This thesis contains the results of the research on the burial of organic carbon in the North Sea as it was carried out at the Netherlands Institute for Sea Research in the period 1993-1997. Carbon in the form of carbon dioxide (CO2 ) is one of the major contributors to the natural greenhouse

  19. A Triple P review of the feasibility of sustainable offshore seaweed production in the North Sea

    NARCIS (Netherlands)

    Burg, van den S.W.K.; Stuiver, M.; Veenstra, F.A.; Bikker, P.; Lopez Contreras, A.M.; Palstra, A.P.; Broeze, J.; Jansen, H.M.; Jak, R.G.; Gerritsen, A.L.; Harmsen, P.F.H.; Kals, J.; Blanco Garcia, A.; Brandenburg, W.A.; Krimpen, van M.M.; Duijn, van A.P.; Mulder, W.J.; Raamsdonk, van L.W.D.

    2013-01-01

    This study focused on the potential of seaweed, cultivated in the North Sea, as a sustainable and profitable resource for feed and non-food applications. Seawood production can take place as part of multi-use platforms at sea (MUPS). A review of the state-of-the-art in seaweed production and its

  20. Scottish Sea Lochs: High Resolution Archives of North Atlantic Climate

    Science.gov (United States)

    Norgaard-Pedersen, N.; Austin, W. E.; Cage, A. G.; Shimmield, T. M.; Gillibrand, P. A.

    2002-12-01

    The sea lochs (fjords) of NW Scotland bridge the land-ocean interface in a region of Europe which is particularly well situated to monitor changes in westerly air flow. Inter-annual atmospheric circulation changes at this latitude are largely governed by the North Atlantic Oscillation (NAO), in turn influencing both westerlies and precipitation. Comparing two extreme recent NAO years, circulation modelling results from Loch Sunart, NW Scotland, reveal a clear response to freshwater runoff and wind forcing in both magnitude and rate of deep-water renewal events. Scottish fjords, because of the relatively small impact which salinity has on d18Owater (0.18 % per salinity unit), potentially provide NW Europe's most useful study sites in coastal palaeoclimate research, particularly where palaeotemperature is the primary record of interest. New data from a high-resolution record (7 yr sample resolution), spanning the last two millennia, from the deepest part of the main basin of Loch Sunart illustrate significant multi-decadal to centennial scale variability in the sedimentary and stable isotope record of epibenthic foraminifera Cibicides lobatulus. The long-term pattern in benthic d18O appears to reflect bottom water temperature differences of 1-2§C, resolving climatic periods such as the Medieval Warm Period and the Little Ice Age. Since the core site is connected with shelf waters (i.e. no shallow sill) it seems likely that this paleotemperature reflects changing shelf water, not the exchange process as a function of long-term runoff/wind forcing. Grain size data and XRF data point to catchment-wide responses (weathering and erosion) which appear to show the largest variability during the last millennium, driven either by rainfall and temperature and/or land-use. Pb-isotope data, constraining the modern and industrial period, suggest accelerated sedimentation rates over this interval. On-going work attempts to calibrate proxy data with instrumental historical data.

  1. Oil Droplet Clouds Suspended in the Sea: Can They Be Remotely Detected?

    Directory of Open Access Journals (Sweden)

    Zbigniew Otremba

    2016-10-01

    Full Text Available Oil floating on the sea surface can be detected by both passive and active methods using the ultraviolet-to-microwave spectrum, whereas oil immersed below the sea surface can signal its presence only in visible light. This paper presents an optical model representing a selected case of the sea polluted by an oil suspension for a selected concentration (10 ppm located in a layer of exemplary thickness (5 m separated from the sea surface by an unpolluted layer (thickness 1 m. The impact of wavelength and state of the sea surface on reflectance changes is presented based on the results of Monte Carlo ray tracing. A two-wavelength index of reflectance is proposed to detect oil suspended in the water column (645–469 nm.

  2. Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas

    OpenAIRE

    van Ginneken, Vincent JT; Helsper, Johannes PFG; de Visser, Willem; van Keulen, Herman; Brandenburg, Willem A

    2011-01-01

    Abstract Background In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (...

  3. Acute toxicities of crude oils and oil-dispersant mixtures to Red sea fishes and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Eisler, R.

    1975-11-01

    Crude oil from fields in the Persian Gulf and in the Sinai plus a chemical oil dispersant were tested, using static bioassay procedures, for toxicity to adults or juveniles of ten marine species: Heteroxenia fuscescens, a soft coral; Nerita forskali and Drupa granulata, gastropod molluscs; Mytilus variabilis, a mussel; Acanthopleura haddoni, a chiton (mollusc); Echinometra mathaei, sea urchin; Calcinus latens, a hermit crab; Palaemon pacificus, a shrimp; Parupeneus barberinus, goatfish; and Siganus rivulatus, rabbitfish. Concentrations fatal to 50 percent of individual test species in 168 hours, LC-50 (168 h), ranged from 0.74 to more than 30.0 ml/liter for Persian Gulf crude, from 14.5 to more than 30.0 ml/liter for Sinai crude, and from 0.006 to 0.064 ml/liter for the dispersant. In general, fishes and crustaceans were the most sensitive groups assayed and molluscs the most resistant. LC-50 (168 h) values for oil-dispersant mixtures of 10 parts oil to 1 part dispersant (v/v) for selected species ranged from 0.047 to 0.152 ml/liter which appears to reflect the biocidal properties of the dispersant. Some individuals that survived immersion in high concentrations of the test compounds for 168 h were adversely affected during treatment and afterwards.

  4. Native carbonoxidation microorganisms in bioremedetion Northern Caspian sea from oil pollution

    Directory of Open Access Journals (Sweden)

    V. V. Gridneva

    2010-01-01

    Full Text Available The 26 strains microorganisms - degradation oil have been isolated from shelf water North Caspian. The high emulsifying ability relative to benzine, kerosene and diesel-fuel oil relevantly were possessed the 11 strains. The 4 cultures exhibiting degradation of oil rates 43-49 %, respectively, were selected.

  5. Hourly to Decadal variability of sea surface carbon parameters in the north western Mediteranean Sea

    Science.gov (United States)

    Boutin, Jacqueline; Merlivat, Liliane; Antoine, David; Beaumont, Laurence; Golbol, Melek; Velluci, Vincenzo

    2017-04-01

    Sea surface CO2 fugacity, fCO2, is recorded hourly in the north western Mediterranean Sea since 2013 by two CARIOCA (Carbon Interface Ocean Atmosphere) sensors installed on the BOUSSOLE (Buoy for the acquisition of long term optical time series, http://www.obs-vlfr.fr/Boussole/html/project/introduction.php) mooring at 3m and 10m depth. fCO2 exhibits a large seasonal cycle, about 150 microatm peak to peak, very consistent with earlier CARIOCA measurements taken in 1995-1999 at the DYFAMED site (located 6km apart from the BOUSSOLE mooring) (Hood and Merlivat, JMR, 2001; Copin-Montegut et al., Mar. Chem., 2004): this seasonal cycle is driven primarily by intense mixing in Winter, biological uptake during Spring and warming during Summer. Interannual variability of these processes leads to interannual variability of monthly mean fCO2 that can reach more than 20 microatm. The short term variability (1 hour to 1 week) is large, especially during Summer 2014 (more than 40 microatm) due to a very strong vertical stratification and to the influence of internal waves. The hourly CARIOCA measurements allow to correctly filter out the high frequency variability while the three year long time series allow to smooth out interannual variability. Hence, for the first time, we get a precise estimate of the change of fCO2 in surface waters within 20 years. Over the 1995-2015 interval, we estimate an increase of fCO2 computed at a constant temperature of 13˚ C equal to 1.8 microatm per year. Given the alkalinity/salinity relationship in this region, we estimate mean annual rates of change of -0.0023+/-0.0001 pH unit and of +1.47+/-0.03 μmol kg-1 for pH and DIC respectively. These results give a quantitative estimate of the penetration of anthropogenic carbon in the surface waters of the northwestern Mediterranean Sea, about 80% via air-sea exchange and 20% via transport of carbon from the Atlantic across the Strait of Gibraltar as suggested by Palmieri et al (BG, 2015). We estimate

  6. Modelling the bidirectional reflectance distribution functions (BRDF of sea areas polluted by oil

    Directory of Open Access Journals (Sweden)

    Zbigniew Otremba

    2004-12-01

    Full Text Available The paper discusses the possibilities of modelling the bi-directional reflectance distribution function (BRDF in sea areas polluted by oil. Three sea basin models are considered: a coastal one free of oil, one polluted by an oil film and one polluted by an oil emulsion. The following concentrations of oil were compared: for the film, 1 cm3 of oil per 1 m2 water surface, for the emulsion 1 cm3 of oil in 1 m3 of water. The optical properties of Romashkino crude oil were taken into consideration, as were various angles of incident solar light. The conversion of BRDFs into a directional distribution of the optical contrast of polluted areas is demonstrated.

  7. Phosphorus binding by poorly crystalline iron oxides in North Sea sediments

    NARCIS (Netherlands)

    Slomp, C.P.; Gaast, S. J. van der; Raaphorst, W. van

    1996-01-01

    Differential X-ray powder diffraction (DXRD) and extraction procedures were used to characterize the iron oxides present in four sediments from contrasting environments in the North Sea. Stations were located in depositional areas on the southern shelf (German Bight) and on the north-eastern

  8. Regional cenozoic uplift and subsidence events in the southeastern North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Jordt, H.

    1995-12-31

    The Paleocene topography of the Fennoscandian Shield is indicated by outbuilding towards the Central Trough and the Ringkoebing-Fyn High. From Eocene until Pliocene time three events of relative vertical movements are indicated by changes in outbuilding directions and reflection termination patterns in the central North Sea. The firs event of uplift was in the Eocene and resulted in relative uplift of the Mid North Sea High and contemporary subsidence east of it, indicated by a change in outbuilding from north to west. A second event of uplift is indicated to the north of the study area at the Eocene-Oligocene boundary by renewed southward outbuilding in the Norwegian-Danish Basin. In Miocene until Early Pliocene time a relatively stationary, almost east-west striking, basin margin was probably located to the north along the Tornquist Zone as indicated by the continued outbuilding towards the Ringkoebing-Fyn High. A third event of relative uplift is indicated east of the study area by changes in the Pliocene outbuilding pattern. After the first event of uplift it appears that the deepest parts of the Eocene North Sea Basin was located more easterly than the deepest part are today. Apparently the two latest uplift events north and east of the study area were related to movements of, or along the Tornquist Zone or to regional uplift of the Fennoscandian Shield finally resulting in the present-day configuration of the North Sea. (au) 11 refs.

  9. Regional seesaw between the North Atlantic and Nordic Seas during the last glacial abrupt climate events

    Directory of Open Access Journals (Sweden)

    M. Wary

    2017-06-01

    Full Text Available Dansgaard–Oeschger oscillations constitute one of the most enigmatic features of the last glacial cycle. Their cold atmospheric phases have been commonly associated with cold sea-surface temperatures and expansion of sea ice in the North Atlantic and adjacent seas. Here, based on dinocyst analyses from the 48–30 ka interval of four sediment cores from the northern Northeast Atlantic and southern Norwegian Sea, we provide direct and quantitative evidence of a regional paradoxical seesaw pattern: cold Greenland and North Atlantic phases coincide with warmer sea-surface conditions and shorter seasonal sea-ice cover durations in the Norwegian Sea as compared to warm phases. Combined with additional palaeorecords and multi-model hosing simulations, our results suggest that during cold Greenland phases, reduced Atlantic meridional overturning circulation and cold North Atlantic sea-surface conditions were accompanied by the subsurface propagation of warm Atlantic waters that re-emerged in the Nordic Seas and provided moisture towards Greenland summit.

  10. Efficiency of equipment to reduce the harmful effects of oil spills at sea - an overview

    International Nuclear Information System (INIS)

    Loeset, S.

    1993-08-01

    The annual discharge of petroleum hydrocarbons to the marine environment is about 3.2 million metric tonnes. About 15% of this discharge is caused by accidental spills at sea. The paper gives an overview of the commonly available oil spill response systems with emphasis on cold waters. In principle the oil spill combat systems at sea can be divided into mechanical containment and recovery, chemical dispersants and in-situ burning. The paper highlights the applicability and efficiency of these combat systems under various conditions (weathering state of the oil, sea state and wind, etc.). 25 refs., 10 figs

  11. Palaeoenvironmental changes across the Danian–Selandian boundary in the North Sea Basin

    DEFF Research Database (Denmark)

    Clemmensen, Anne; Thomsen, Erik

    2005-01-01

    cores from Storebælt in the eastern part of the North Sea Basin, we have reconstructed the palaeoenvironmental changes across the boundary. The benthic foraminiferal faunas belong to the “Midway-type fauna”. They are extremely rich and more than 260 taxa have been recognized. Q-mode cluster analysis......, the sea bottom conditions became colder and more acidic. This resulted in partial dissolution of the carbonates and the deposition shifted from marl to clay. Comparison with records from the Western Pyrenees, the Nile Basin and the eastern North America suggests that sea-level changes across the Danian......The Danian–Selandian boundary (not, vert, similar60 Ma) marks the cessation of 40 million years of carbonate deposition in the North Sea Basin and a shift to siliciclastic deposition. On the basis of variations in lithology, benthic and planktonic foraminifera and calcareous nannofossils in three...

  12. Sensitivity of modeled atmospheric nitrogen species and nitrogen deposition to variations in sea salt emissions in the North Sea and Baltic Sea regions

    Directory of Open Access Journals (Sweden)

    D. Neumann

    2016-03-01

    Full Text Available Coarse sea salt particles are emitted ubiquitously from the ocean surface by wave-breaking and bubble-bursting processes. These particles impact the atmospheric chemistry by affecting the condensation of gas-phase species and, thus, indirectly the nucleation of new fine particles, particularly in regions with significant air pollution. In this study, atmospheric particle concentrations are modeled for the North Sea and Baltic Sea regions in northwestern Europe using the Community Multiscale Air Quality (CMAQ modeling system and are compared to European Monitoring and Evaluation Programme (EMEP measurement data. The sea salt emission module is extended by a salinity-dependent scaling of the sea salt emissions because the salinity in large parts of the Baltic Sea is very low, which leads to considerably lower sea salt mass emissions compared to other oceanic regions. The resulting improvement in predicted sea salt concentrations is assessed. The contribution of surf zone emissions is considered separately. Additionally, the impacts of sea salt particles on atmospheric nitrate and ammonium concentrations and on nitrogen deposition are evaluated. The comparisons with observational data show that sea salt concentrations are commonly overestimated at coastal stations and partly underestimated farther inland. The introduced salinity scaling improves the predicted Baltic Sea sea salt concentrations considerably. The dates of measured peak concentrations are appropriately reproduced by the model. The impact of surf zone emissions is negligible in both seas. Nevertheless, they might be relevant because surf zone emissions were cut at an upper threshold in this study. Deactivating sea salt leads to minor increases in NH3 +  NH4+ and HNO3 +  NO3− and a decrease in NO3− concentrations. However, the overall effect on NH3 +  NH4+ and HNO3 +  NO3− concentrations is smaller than the deviation from the measurements. Nitrogen wet deposition is

  13. A decision support system for assessing offshore wind energy potential in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Wanderer, T.; Schillings, C. [German Aerospace Center (DLR), Systems Analysis and Technology Assessment, Stuttgart (Germany); Cameron, L.; Veum, K. [Energy research Center of the Netherlands ECN, Policy Studies Department, Amsterdam (Netherlands); Tjalling van der Wal, J. [IMARES, Wageningen UR, Den Helder (Netherlands); Jacquemin, J. [GL Garrad Hassan, Paris (France)

    2012-10-15

    Offshore wind energy (OWE) in the North Sea has the potential to meet large share of Europe's future electricity demand. To deploy offshore wind parks in a rational way, the overall OWE potential has to be realistically determined. This has to be done on an international, cross-border level and by taking into account the existing man-made and nature-related uses of the North Sea. As spatial conflicts will arise between existing uses and the new OWE uses, a Decision Support System (DSS) based on a Geographic Information System (GIS) was developed. Based on data of existing sea uses and calculation rules for spatial prioritisation analysis, the DSS helps in identifying areas that are (1) generally suitable for offshore wind power, (2) strictly excluded or (3) negotiable with respect to other existing sea uses. The combination of this conflict analysis together with cost assumptions for offshore wind farms and their expected electricity yield leads to identification of favourable areas for OWE deployment in the North Sea. This approach helps to reduce the conflict between offshore wind deployment and existing sea uses in the North Sea for future planning. The results can assist decision makers in developing transnational roadmaps for OWE.

  14. Contrasting trends in North Atlantic deep-water formation in the Labrador Sea and Nordic Seas during the Holocene

    NARCIS (Netherlands)

    Renssen, H.; Goosse, H.; Fichefet, T.

    2005-01-01

    The Holocene North Atlantic deep-water formation is studied in a 9,000-year long simulation with a coupled climate model of intermediate complexity, forced by changes in orbital forcing and atmospheric trace gas concentrations. During the experiment, deep-water formation in the Nordic Seas is

  15. Improving the assessment and management of the plaice stock complex between the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Ulrich, Clara; Boje, Jesper; Cardinale, Massimiliano

    2012-01-01

    Plaice in Kattegat and Skagerrak have traditionally been considered as one stock unit. However the collected information on biology and fishery in areas between the North and Baltic Seas suggest changes are needed in assessment units as well as in management areas. Plaice in Skagerrak (Division 20...

  16. Connectivity of larval cod in the transition area between North Sea and Baltic Sea and potential implications for fisheries management

    DEFF Research Database (Denmark)

    Huwer, Bastian; Hinrichsen, H.-H.; Hüssy, Karin

    2016-01-01

    in the transition area between North Sea and Baltic were investigated to (i) determine long-term trends and variability in advective transport of larvae from spawning grounds to juvenile nursery areas, (ii) estimate the degree of exchange between different management areas, and (iii) compare the results...

  17. An operational search and rescue model for the Norwegian Sea and the North Sea

    Science.gov (United States)

    Breivik, Øyvind; Allen, Arthur A.

    A new operational, ensemble-based search and rescue model for the Norwegian Sea and the North Sea is presented. The stochastic trajectory model computes the net motion of a range of search and rescue objects. A new, robust formulation for the relation between the wind and the motion of the drifting object (termed the leeway of the object) is employed. Empirically derived coefficients for 63 categories of search objects compiled by the US Coast Guard are ingested to estimate the leeway of the drifting objects. A Monte Carlo technique is employed to generate an ensemble that accounts for the uncertainties in forcing fields (wind and current), leeway drift properties, and the initial position of the search object. The ensemble yields an estimate of the time-evolving probability density function of the location of the search object, and its envelope defines the search area. Forcing fields from the operational oceanic and atmospheric forecast system of The Norwegian Meteorological Institute are used as input to the trajectory model. This allows for the first time high-resolution wind and current fields to be used to forecast search areas up to 60 h into the future. A limited set of field exercises show good agreement between model trajectories, search areas, and observed trajectories for life rafts and other search objects. Comparison with older methods shows that search areas expand much more slowly using the new ensemble method with high resolution forcing fields and the new leeway formulation. It is found that going to higher-order stochastic trajectory models will not significantly improve the forecast skill and the rate of expansion of search areas.

  18. A multi-stage oil-water-separating process design for the sea oil spill recovery robot

    Science.gov (United States)

    Zhang, Min-ge; Wu, Jian-guo; Lin, Xinhua; Wang, Xiao-ming

    2018-03-01

    Oil spill have the most common pollution to the marine ecological environment. In the late stage of physical method recovery, because of the thin oil and the strong sea breeze, the recovery vessels has low efficiency and high energy consumption. This paper develops a multi-stage oil-water-separating process carried by the sea oil spill recovery robot in severe conditions. This design consists of three separation process, among which both the first and third process adopt corrugated sheets horizontal oil-water separator, while the second is hydraulic rotary breaker. This design also equiptment with rectifier and cyclone separator and other important components. This process has high flexibility and high recovery efficiency. The implement effect is significant.

  19. Virulence Profiles of Vibrio vulnificus in German Coastal Waters, a Comparison of North Sea and Baltic Sea Isolates

    Directory of Open Access Journals (Sweden)

    Nadja Bier

    2015-12-01

    Full Text Available Vibrio vulnificus is a halophilic bacterium of coastal environments known for sporadically causing severe foodborne or wound infections. Global warming is expected to lead to a rising occurrence of V. vulnificus and an increasing incidence of human infections in Northern Europe. So far, infections in Germany were exclusively documented for the Baltic Sea coast, while no cases from the North Sea region have been reported. Regional variations in the prevalence of infections may be influenced by differences in the pathogenicity of V. vulnificus populations in both areas. This study aimed to compare the distribution of virulence-associated traits and genotypes among 101 V. vulnificus isolates from the Baltic Sea and North Sea in order to assess their pathogenicity potential. Furthermore, genetic relationships were examined by multilocus sequence typing (MLST. A high diversity of MLST sequences (74 sequence types and differences regarding the presence of six potential pathogenicity markers were observed in the V. vulnificus populations of both areas. Strains with genotypes and markers associated with pathogenicity are not restricted to a particular geographic region. This indicates that lack of reported cases in the North Sea region is not caused by the absence of potentially pathogenic strains.

  20. Atmospheric input of trace substances into the North Sea and the Baltic Sea. Stoffeintrag in Nord- und Ostsee ueber die Atmosphaere

    Energy Technology Data Exchange (ETDEWEB)

    Grassl, H; Eppel, D; Petersen, G; Schneider, B; Weber, H; Gandrass, J; Reinhardt, K H; Wodarg, D; Fliess, J

    1989-01-01

    The concentrations and deposition of atmospheric trace substances were measured over the Kiel Bight and the Southern North Sea. A European longrange-transport model was used to calculate the atmospheric concentrations of trace metals and their deposition into the North Sea and the Baltic Sea. Natural and anthropogenic emitted element concentrations could be separated definitely by the measurements, and preferred transport directions of anthropogenic contributions could be found. Concentrations measured over the North Sea could be related to the surrounding emission areas by airmass trajectory analyses. The deposition measurements show that the main removal process is due to deposition by precipitation. Calculated and measured concentrations at several receptor points agreed well. The model results confirm the dominating role of wet deposition. It could be shown that extrapolations from measurements at coastal stations to the whole sea area tend to overestimate the total deposition into North Sea and Baltic Sea. (orig.) With 78 refs., 26 tabs., 85 figs.

  1. Surfactant control of air-sea gas exchange from North Sea coastal waters and the Atlantic Meridional Transect

    Science.gov (United States)

    Pereira, R.

    2016-02-01

    Suppression of gas transfer velocity (kw) by surfactants are well established, both in laboratory wind flumes and purposeful oceanic releases. However, the effects on kw of time and space varying concentrations of natural surfactant are inadequately studied. We have developed an automated gas exchange tank for simultaneous high precision measurement of kw in unmodified seawater samples. Here we present data from two studies along a coastal North Sea transect during 2012-2013 and the Atlantic Meridional Transect (AMT) 24 from September to November 2014. Measurements of surfactant activity (SA), CDOM absorbance and chlorophyll-a have enabled us to characterize the effects of variable amounts of natural surfactant on kw. North Sea coastal waters range in k660 (kw normalized to the value for CO2 in freshwater at 20oC) was 6.8-24.5 cm hr-1 (n=20), with the ranges of SA, total CDOM absorbance (200-450 nm) and chlorophyll-a measured in the surface microlayer (SML) of our seawater samples were 0.08-0.38 mg l-1 T-X-100, 0.13-4.7 and 0.09-1.54 µg l-1, respectively. The AMT k660 ranged from 7.0-23.9 cm hr-1 (n=22), with SA measured in the SML and subsurface water (SSW) of our seawater samples ranging from 0.15-1.08 mg l-1 T-X-100 and 0.07-0.43 mg l-1 T-X-100, respectively. Importantly, we found 12-45% (North Sea) and 1-43% (AMT) k660 suppression relative to Milli-Q water that relate to seasonal and spatial differences in SA. The North Sea demonstrated notable seasonal influences on k660 suppression that were related to CDOM absorbance and chlorophyll-a. The degree of k660 suppression was highest in summer consistent with k660 control by natural surfactant. The degree of k660 suppression decreased with distance offshore in the North Sea and displayed a strong relationship with SA (r2 = 0.51-0.64, p = 0.02, n = 20). The AMT demonstrated notable differences in k660 suppression between hemispheres and across the Longhurst Provinces but the overall relationship between k660

  2. A decision support system for assessing offshore wind energy potential in the North Sea

    International Nuclear Information System (INIS)

    Schillings, Christoph; Wanderer, Thomas; Cameron, Lachlan; Tjalling van der Wal, Jan; Jacquemin, Jerome; Veum, Karina

    2012-01-01

    Offshore wind energy (OWE) in the North Sea has the potential to meet large share of Europe’s future electricity demand. To deploy offshore wind parks in a rational way, the overall OWE potential has to be realistically determined. This has to be done on an international, cross-border level and by taking into account the existing man-made and nature-related uses of the North Sea. As spatial conflicts will arise between existing uses and the new OWE uses, a Decision Support System (DSS) based on a Geographic Information System (GIS) was developed. Based on data of existing sea uses and calculation rules for spatial prioritisation analysis, the DSS helps in identifying areas that are (1) generally suitable for offshore wind power, (2) strictly excluded or (3) negotiable with respect to other existing sea uses. The combination of this conflict analysis together with cost assumptions for offshore wind farms and their expected electricity yield leads to identification of favourable areas for OWE deployment in the North Sea. This approach helps to reduce the conflict between offshore wind deployment and existing sea uses in the North Sea for future planning. The results can assist decision makers in developing transnational roadmaps for OWE. - Highlights: ► Decision Support System (DSS) to identify offshore wind energy (OWE) potential in the North Sea. ► Spatial analysis of existing sea use functions and offshore wind energy potential. ► Input parameters of DSS depend on the level of OWE spatial priority assumed by the user. ► DSS performs the required calculations and provides results in form of maps and statistics. ► DSS available after registration at (www.windspeed.eu).

  3. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal

    Science.gov (United States)

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; TeSlaa, Joshua L.; Jónsson, Jón Eínar; Ballard, Jennifer R.; Harms, Naomi Jane; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology. PMID:26677841

  4. Avian influenza ecology in North Atlantic sea ducks: Not all ducks are created equal

    Science.gov (United States)

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; Teslaa, Joshua L.; Jónsson, Jón Einar; Ballard, Jennifer R.; Harms, Naomi Jnae; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  5. Radiocaesium (137Cs) in marine mammals from Svalbard, the Barents Sea and the North Greenland Sea

    International Nuclear Information System (INIS)

    Andersen, Magnus; Gwynn, Justin P.; Dowdall, Mark; Kovacs, Kit M.; Lydersen, Christian

    2006-01-01

    Specific activities of the anthropogenic radionuclide, 137 Cs, were determined in marine mammals from Svalbard and the Barents and North Greenland Seas. Muscle samples were collected from 12 polar bears, 15 ringed seals, 10 hooded seals, 7 bearded seals, 14 harp seals, one walrus, one white whale and one blue whale in the period 2000-2003. The mean concentrations (± SD) of 137 Cs were: 0.72 ± 0.62 Bq/kg wet weight (w.w.) for polar bears; 0.49 ± 0.07 Bq/kg w.w. for ringed seals; 0.25 ± 0.10 Bq/kg w.w. for hooded seals; 0.22 ± 0.11 Bq/kg w.w. for bearded seals; 0.36 ± 0.13 Bq/kg w.w. for harp seals; 0.67 Bq/kg w.w. for the white whale sample; 0.24 Bq/kg w.w. for the blue whale; and below detection limit for the walrus. Significant differences in 137 Cs specific activities between some of the species were found. Ringed seals had higher specific activities than the other seal species in the study. Bearded seals and hooded seals had similar values, which were both significantly lower than the harp seal values. The results in the present study are consistent with previous reported results, indicating low specific activities of 137 Cs in Arctic marine mammals in the Barents Sea and Greenland Sea region during the last 20 years. The species specific differences found may be explained by varying diet or movement and distribution patterns between species. No age related patterns were found in specific activities for the two species (polar bears and hooded seals) for which sufficient data was available. Concentration factors (CF) of 137 Cs from seawater were determined for polar bears, ringed, bearded, harp and hooded seals. Mean CF values ranged from 79 ± 32 (SD) for bearded seals sampled in 2002 to 244 ± 36 (SD) for ringed seals sampled in 2003 these CF values are higher than those reported for fish and benthic organisms in the literature, suggesting bioaccumulation of 137 Cs in the marine ecosystem

  6. The acclimative biogeochemical model of the southern North Sea

    Science.gov (United States)

    Kerimoglu, Onur; Hofmeister, Richard; Maerz, Joeran; Riethmüller, Rolf; Wirtz, Kai W.

    2017-10-01

    Ecosystem models often rely on heuristic descriptions of autotrophic growth that fail to reproduce various stationary and dynamic states of phytoplankton cellular composition observed in laboratory experiments. Here, we present the integration of an advanced phytoplankton growth model within a coupled three-dimensional physical-biogeochemical model and the application of the model system to the southern North Sea (SNS) defined on a relatively high resolution (˜ 1.5-4.5 km) curvilinear grid. The autotrophic growth model, recently introduced by Wirtz and Kerimoglu (2016), is based on a set of novel concepts for the allocation of internal resources and operation of cellular metabolism. The coupled model system consists of the General Estuarine Transport Model (GETM) as the hydrodynamical driver, a lower-trophic-level model and a simple sediment diagenesis model. We force the model system with realistic atmospheric and riverine fluxes, background turbidity caused by suspended particulate matter (SPM) and open ocean boundary conditions. For a simulation for the period 2000-2010, we show that the model system satisfactorily reproduces the physical and biogeochemical states of the system within the German Bight characterized by steep salinity; nutrient and chlorophyll (Chl) gradients, as inferred from comparisons against observation data from long-term monitoring stations; sparse in situ measurements; continuous transects; and satellites. The model also displays skill in capturing the formation of thin chlorophyll layers at the pycnocline, which is frequently observed within the stratified regions during summer. A sensitivity analysis reveals that the vertical distributions of phytoplankton concentrations estimated by the model can be qualitatively sensitive to the description of the light climate and dependence of sinking rates on the internal nutrient reserves. A non-acclimative (fixed-physiology) version of the model predicted entirely different vertical profiles

  7. Eddy Mediated Nutrient Pattern in the North Eastern Arabian Sea

    Science.gov (United States)

    Thachaparambil, M.; Moolakkal Antony, R.; B R, S.; V N, S.; N, C.; M, S.

    2016-02-01

    A Cold Core Eddy (CCE) mediated nutrient pattern in the North Eastern Arabian Sea (NEAS) is explained based on in situ measurments during March 2013 onboard FORV Sagar Sampada which was not reported earlier in the area. Samples for physical, chemical and biological parameters were collected in 5 stations along the diameter of the eddy and following standard protocols. The core of the CCE is identified at 21°20.38'N; 66°30.68'E with a diameter of 120Km. Earlier studies explaining the process and the forcing mechanism of the particular eddy records that, the eddy is short term (1-3 months) and is regular during the season. Surface waters were well oxygenated (>4.8 ml L-1) in the core. Surface value of nutrients viz., Nitrate, Nitrite, Silicate and phosphate in the core regions was 0.9µM, 0.01 µM, 0.5 µM and 0.7 µM respectively indicating upwelling in the core. Spring intermonsoon (SIM) is generally termed as a transition period between the active winter and summer seasons and as per earlier studies, high biological production and the regularly occurring Noctilica bloom is supported by the nutrient loading due to convective mixing during winter as well as regenerated production. However, present observations shows that, nutrient pumping due to the upwelling associated with the CCE also contributes for sustaining high biological production and are evident in the Chl a and mesozooplankton biovolume which records values of 4.35mg/m3 and 1.09ml/m3 respectively in the core. An intense Noctiluca blooms observed in the western flank of the eddy (Chl a 13.25 mg/m3; cell density 5.8×106 cells/litre), where Nitrate concentration records 1.04µM explains the role of such mesoscale processes in the sustenance of the HAB events. While eastern flank of the CCE showed typical open ocean condition of the season showing Nitrate 0.08µM; Chl a 0.23mg/m3; and phytoplankton cell density as 421 cells/litre. Keywords: Cold core eddy, nutrients, NEAS, SIM, biological production

  8. Danish oil and gas reserves in the North Sea

    DEFF Research Database (Denmark)

    Larsen, Vibe Busk

    2018-01-01

    Statistics Denmark’s Green National Accounts highlight the link between the economy and the environment through environmental-economic accounting. The feature publication titled “Green National Accounts for Denmark 2015-2016” is the final outcome of a three-year project which has developed a full...... in the report. Furthermore, the report includes a chapter presenting a number of SDG-indicators for Denmark based on data from the accounts. A summary of the recent developments based on selected key indicators from the accounts is also presented....

  9. Observed sea-level rise in the north Indian Ocean coasts during the past century

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    Content-Type text/plain; charset=UTF-8 91 Observed sea-level rise in the north Indian Ocean coasts during the past century A. S. Unnikrishnan National Institute of Oceanography, Dona Paula, Goa-403004 unni@nio.org Introduction Sea-level... rise is one of the good indicators of global warming. Rise in sea level occurs mainly through melting of glaciers, thermal expansion due to ocean warming and some other processes of relatively smaller magnitudes. Sea level rise is a global...

  10. Deglacial and Holocene sea-ice variability north of Iceland and response to ocean circulation changes

    Science.gov (United States)

    Xiao, Xiaotong; Zhao, Meixun; Knudsen, Karen Luise; Sha, Longbin; Eiríksson, Jón; Gudmundsdóttir, Esther; Jiang, Hui; Guo, Zhigang

    2017-08-01

    Sea-ice conditions on the North Icelandic shelf constitute a key component for the study of the climatic gradients between the Arctic and the North Atlantic Oceans at the Polar Front between the cold East Icelandic Current delivering Polar surface water and the relatively warm Irminger Current derived from the North Atlantic Current. The variability of sea ice contributes to heat reduction (albedo) and gas exchange between the ocean and the atmosphere, and further affects the deep-water formation. However, lack of long-term and high-resolution sea-ice records in the region hinders the understanding of palaeoceanographic change mechanisms during the last glacial-interglacial cycle. Here, we present a sea-ice record back to 15 ka (cal. ka BP) based on the sea-ice biomarker IP25, phytoplankton biomarker brassicasterol and terrestrial biomarker long-chain n-alkanols in piston core MD99-2272 from the North Icelandic shelf. During the Bølling/Allerød (14.7-12.9 ka), the North Icelandic shelf was characterized by extensive spring sea-ice cover linked to reduced flow of warm Atlantic Water and dominant Polar water influence, as well as strong meltwater input in the area. This pattern showed an anti-phase relationship with the ice-free/less ice conditions in marginal areas of the eastern Nordic Seas, where the Atlantic Water inflow was strong, and contributed to an enhanced deep-water formation. Prolonged sea-ice cover with occasional occurrence of seasonal sea ice prevailed during the Younger Dryas (12.9-11.7 ka) interrupted by a brief interval of enhanced Irminger Current and deposition of the Vedde Ash, as opposed to abruptly increased sea-ice conditions in the eastern Nordic Seas. The seasonal sea ice decreased gradually from the Younger Dryas to the onset of the Holocene corresponding to increasing insolation. Ice-free conditions and sea surface warming were observed for the Early Holocene, followed by expansion of sea ice during the Mid-Holocene.

  11. Assessment of Undiscovered Oil and Gas Resources of the Red Sea Basin Province

    Science.gov (United States)

    ,

    2010-01-01

    The U.S. Geological Survey estimated mean volumes of 5 billion barrels of undiscovered technically recoverable oil and 112 trillion cubic feet of recoverable gas in the Red Sea Basin Province using a geology-based assessment methodology.

  12. Effect of oil spill on the microbial population in Andaman Sea around Nicobar Island

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.

    The microbial studiees of the follow up cruise by FORV Sagar Sampada (cruise No. 113), 9 months after the oil spill in the Andaman Sea due to accident of VLCC Maersk Navigator revealed disturbance in the natural microbial population. Higher...

  13. Storing CO{sub 2} under the North Sea Basin - A key solution for combating climate change

    Energy Technology Data Exchange (ETDEWEB)

    Skogen, T; Morris, B; Agerup, M; Svenningsen, S Oe; Kropelien, K F; Solheim, M; Northmore, B; Dixon, T; O' Carroll, K; Greaves, A; Golder, J; Selmer-Olsen, S; Sjoeveit, A; Kaarstad, O; Riley, N; Wright, I; Mansfield, C

    2007-06-15

    This report represents the first deliverable of the North Sea Basin Task Force, which Norway and the UK established in November 2005 to work together on issues surrounding the transport and storage of CO{sub 2} beneath the North Sea. The North Sea represents the best geological opportunity for storing our CO{sub 2} emissions away from the atmosphere for both the UK and Norway

  14. Assessment of undiscovered oil and gas resources in the North-Central Montana Province, 2017

    Science.gov (United States)

    Schenk, Christopher J.; Mercier, Tracey J.; Brownfield, Michael E.; Tennyson, Marilyn E.; Woodall, Cheryl A.; Le, Phuong A.; Klett, Timothy R.; Gaswirth, Stephanie B.; Finn, Thomas M.; Pitman, Janet K.; Marra, Kristen R.; Leathers-Miller, Heidi M.

    2018-02-12

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable resources of 55 million barrels of oil and 846 billion cubic feet of gas in the North-Central Montana Province.

  15. The effects of the Sea Empress oil spill on the plankton of the Southern Irish Sea

    International Nuclear Information System (INIS)

    Batten, S.D.; Allen, R.J.S.; Wotton, C.O.M.

    1998-01-01

    This study investigates the effects of the Sea Empress oil spill on the local plankton communities which are an important component of the marine ecosystem. The Continuous Plankton Recorder survey has monitored the plankton in this area since 1970 giving an extensive time series for comparison with post-spill samples. The analytical procedures applied and results obtained are presented and reveal that, with some exceptions, no significant effects were evident. Barnacle larvae were not recorded post-spill and the spring zooplankton community was somewhat different to the previous year. A long-term trend is apparent in the community but the most common taxa showed no significant changes, suggesting a minor shift in species composition rather than a dramatic change. (author)

  16. A prototype statistical approach of oil pollution in the Mediterranean Sea

    International Nuclear Information System (INIS)

    Ventikos, N.P.; Psaraftis, H.N.

    1998-01-01

    In this paper, we present a detailed statistical survey of oil pollution in the greater area of the Mediterranean Sea (with a preference in the Greek Seas: eg. the Aegean Sea or the Ioanian Sea and the respective Greek fleet). The Mediterranean Sea exhibits a noticeable increase of oil pollution within the last 15 years as documented by data that is presented within this work. A new electronic data base tool with a multitude of operational capabilities that utilizes data from the REMPEC Organization in raw format is introduced. We further present a statistical analysis of the data which differentiates each incident according to the volume of spilled oil and we conclude with some interesting results and comments. (author)

  17. A comparison of visual observations of surface oil with Synthetic Aperture Radar imagery of the Sea Empress oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Jones, B.

    2001-06-15

    A comparison has been made between the visual observations of surface oil and four satellite-borne Synthetic Aperture Radar (SAR) images taken during the Sea Empress oil spill in February 1996. Whilst the basic oil slick imaging capabilities of SAR are well documented, to be of use at the time of a major oil spill, the imagery must be able to provide information on the thickness of oil. This analysis suggests that, under certain environmental conditions, this is possible. The optimum wind speed for the identification of heavy surface oil is around 5-6 m s{sup -1}. At this wind speed, light and medium sheen is not evident in the imagery and there is a distinction between the backscatter reductions due to heavy sheen and thick brown/black oil. At higher wind speeds, even thick oil slicks readily mix into the water column and their SAR signature weakens. In light winds, pattern recognition is very important to the identification of oil sticks. The images are more sensitive to the presence of sheen within the sheltered waters of Milford Haven than in the open coastal waters, indicating a possible relationship between sheen visibility in satellite-borne SAR and sea state. (author)

  18. Impacts of the north and tropical Atlantic Ocean on the Antarctic Peninsula and sea ice.

    Science.gov (United States)

    Li, Xichen; Holland, David M; Gerber, Edwin P; Yoo, Changhyun

    2014-01-23

    In recent decades, Antarctica has experienced pronounced climate changes. The Antarctic Peninsula exhibited the strongest warming of any region on the planet, causing rapid changes in land ice. Additionally, in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not declined, but has instead undergone a perplexing redistribution. Antarctic climate is influenced by, among other factors, changes in radiative forcing and remote Pacific climate variability, but none explains the observed Antarctic Peninsula warming or the sea-ice redistribution in austral winter. However, in the north and tropical Atlantic Ocean, the Atlantic Multidecadal Oscillation (a leading mode of sea surface temperature variability) has been overlooked in this context. Here we show that sea surface warming related to the Atlantic Multidecadal Oscillation reduces the surface pressure in the Amundsen Sea and contributes to the observed dipole-like sea-ice redistribution between the Ross and Amundsen-Bellingshausen-Weddell seas and to the Antarctic Peninsula warming. Support for these findings comes from analysis of observational and reanalysis data, and independently from both comprehensive and idealized atmospheric model simulations. We suggest that the north and tropical Atlantic is important for projections of future climate change in Antarctica, and has the potential to affect the global thermohaline circulation and sea-level change.

  19. Sea surface temperature and sea ice variability in the subpolar North Atlantic from explosive volcanism of the late thirteenth century

    DEFF Research Database (Denmark)

    Sicre, M. -A.; Khodri, M.; Mignot, J.

    2013-01-01

    In this study, we use IP25 and alkenone biomarker proxies to document the subdecadal variations of sea ice and sea surface temperature in the subpolar North Atlantic induced by the decadally paced explosive tropical volcanic eruptions of the second half of the thirteenth century. The short-and long......-term evolutions of both variables were investigated by cross analysis with a simulation of the IPSL-CM5A LR model. Our results show short-term ocean cooling and sea ice expansion in response to each volcanic eruption. They also highlight that the long response time of the ocean leads to cumulative surface cooling...... and subsurface heat buildup due to sea ice capping. As volcanic forcing relaxes, the surface ocean rapidly warms, likely amplified by subsurface heat, and remains almost ice free for several decades....

  20. Use of X-ray computed tomography in core analysis of tight North Sea Chalk. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mogensen, K.; Stenby, E.H.

    1997-12-01

    This EFP-95 final report summarizes work performed at the Engineering Research Center (IVC-SEP) on the use of CT scanning in core analysis of tight core material from the North Sea. In this work, CT scanning has been applied to chalk material from Danish North Sea oil reservoirs. Results indicate that CT is fast and reliable for prediction of porosity. Typical errors lie within 2-3%. Calculation of fluid saturations requires considerable care from the experimentalists. Saturating a core ought to be performed by pulling vacuum to avoid trapped air bubbles. These bubbles may be produced after subsequent water and gas flooding, thereby ruining the mass balance calculations. Results performed at Stanford University show that if these simple precautions are taken, fluid saturations calculated from CT scanning are generally very accurate. Moreover, it appears that contrast agents need not be added to either phase. Regarding three-phase measurements the results are somewhat disappointing. Previous work using the dual-energy technique has indicated that the accuracy is less than satisfactory, due to an increased noise level at the low-energy setting. More work needs to be done in the future to develop the necessary expertise. The image analysis of the residual oil saturation after a gas flood can be simplified if water is assumed to be immobile during the injection. In that case, the resulting prediction of residual oil saturation is in excellent agreement with measured values. The general conclusion is that CT scanning holds a great potential as an assisting tool in modern core analysis, despite its limitations and the numerous implementation-related problems encountered during this work. (au) EFP-95. 57 refs.

  1. The radon-222 transfer coefficients across air-sea interface determined in the Bering Sea, the Okhotsk Sea and the North Pacific Ocean

    International Nuclear Information System (INIS)

    Kholujskij, S.N.; Anikiev, V.V.; Popov, N.I.

    1995-01-01

    Determination of velocity coefficient for gas flow transfer across the natural sea surface into the atmosphere (K v ) was attempted by means of radon method on board the SRS Academician Alexander Nesmeyanov (July-August 1992). The measurements were conducted in the Bering Sea, the Okhotsk Sea and in the North Pacific Ocean. It is shown that the total range of the K v observed values equaled from 1.8 up to 5.4 m.day, which is within the known limits for other regions of the world ocean. 9 refs., 1 fig

  2. Oil and Natural Gas Pipelines, North America, 2010, Platts

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Oil and Natural Gas Pipeline geospatial data layer contains gathering, interstate, and intrastate natural gas pipelines, crude and product oil pipelines, and...

  3. The fate of oil on cleaned and uncleaned beaches following the Sea Empress incident

    International Nuclear Information System (INIS)

    Swannell, R.P.J.; Mitchell, D.J.; Little, D.I.; Smith, J.

    1997-09-01

    This report summarises the results of surveys of areas affected by the Sea Empress oil spill, commissioned by the Welsh Office, to compare cleaned and untreated shorelines. Details are given of the preliminary assessment of five sites, field methods and analysis of the oil at each site. Recommendations are also given. (UK)

  4. Impact of Expanded North Slope of Alaska Crude Oil Production on Oil Flows in the Contiguous United States (Summary)

    Energy Technology Data Exchange (ETDEWEB)

    DeRosa, Sean e. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flanagan, Tatiana Paz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    Crude oil produced on the North Slope of Alaska (NSA) is primarily transported on the Trans-Alaska Pipeline System (TAPS) to in-state refineries and the Valdez Marine Terminal in southern Alaska. From the Terminal, crude oil is loaded onto tankers and is transported to export markets or to three major locations along the U.S. West Coast: Anacortes-Ferndale area (Washington), San Francisco Bay area, and Los Angeles area. North Slope of Alaska production has decreased about 75% since the 1980s, which has reduced utilization of TAPS.

  5. Recruitment in a changing environment: the 2000s North Sea herring recruitment failure

    DEFF Research Database (Denmark)

    Payne, Mark; Hatfield, E.M.C.; Dickey-Collas, M.

    2009-01-01

    Environmentally induced change appears to be impacting the recruitment of North Sea herring (Clupea harengus). Despite simultaneously having a large adult population, historically low exploitation, and Marine Stewardship Council accreditation (implying sustainability), there have been an unpreced......Environmentally induced change appears to be impacting the recruitment of North Sea herring (Clupea harengus). Despite simultaneously having a large adult population, historically low exploitation, and Marine Stewardship Council accreditation (implying sustainability), there have been...... an unprecedented 6 sequential years of poor juvenile production (recruitment). Analysis suggests that the poor recruitment arises during the larval overwintering phase, with recent survival rates greatly reduced. Contemporary warming of the North Sea has caused significant changes in the plankton community...

  6. Grey gurnard ( Eutrigla gurnadus ) in the North Sea: an emerging key predator?

    DEFF Research Database (Denmark)

    Floeter, J.; Kempf, A.; Vinther, Morten

    2005-01-01

    Grey gurnard (Eutrigla gurnadus) is a widely distributed demersal species in the North Sea that has been ranked frequently among the 10 dominant species. Since the late 1980s, grey gurnard catch rates in the international bottom trawl surveys showed a pronounced increase and it was included...... as an "other predator" in the North Sea multispecies virtual population analysis (MSVPA) in 1997. The MSVPA results estimated grey gurnard to be responsible for approximately 60% of the total predation mortality on age-0 Atlantic cod (Gadus morhua). Long-term MSVPA predictions led to the extinction of North...... Sea cod. As a possible technical reason, the Holling type II functional response implemented in the model was discussed. In the current analysis, it was demonstrated that the Holling type II functional response was not responsible for the extinction of cod in the model, which was rather a true effect...

  7. The contribution of ship emissions to air pollution in the North Sea regions

    Energy Technology Data Exchange (ETDEWEB)

    Matthias, Volker, E-mail: volker.matthias@gkss.d [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Bewersdorff, Ines [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Aulinger, Armin, E-mail: armin.aulinger@gkss.d [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Quante, Markus, E-mail: markus.quante@gkss.d [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck-Strasse 1, 21502 Geesthacht (Germany)

    2010-06-15

    As a consequence of the global distribution of manufacturing sites and the increasing international division of labour, ship traffic is steadily increasing and is becoming more and more important as an origin of air pollution. This study investigates the impact of ship emissions in coastal areas of the North Sea under conditions of the year 2000 by means of a regional chemistry transport model which runs on a sufficiently high resolution to study air pollution in coastal regions. It was found that northern Germany and Denmark in summer suffer from more than 50% higher sulphate, nitrate and ammonium aerosol concentrations due to contributions from ships. The implementation of a sulphur emission control area (SECA) in the North Sea, as it was implemented at the end of 2007, directly results in reduced sulphur dioxide and sulphate aerosol concentrations while nitrate aerosol concentrations are slightly increased. - Ship emissions lead to significantly enhanced air pollution by secondary inorganic aerosols in North Sea coastal areas.

  8. Quantifying pelagic-benthic coupling in the North Sea: Are we asking the right question?

    DEFF Research Database (Denmark)

    Richardson, K.; Cedhagen, T.

    2002-01-01

    is devoted to obtaining more and better data describing this exchange. Efforts to quantify exchange between the water column and the sediment must continue. However, such studies will not, in themselves, lead to a quantification of pelagic-benthic coupling in the North Sea. We identify here other areas......The coupling between pelagic and benthic processes occurs through the signals sent between the water column and the seabed. Huge methodological challenges are associated with the quantification of the signals being sent between these two domains - especially in a relatively shallow and heavily...... fished region such as the North Sea where deployment of sediment traps or bottom mounted cameras or samplers is difficult. Thus, there are relatively few sites in the North Sea for which good data are available for describing pelagic-benthic (or near shore-offsbore) coupling and considerable effort...

  9. Estimation of new production in the North Sea: consequences for temporal and spatial variability of phytoplankton

    DEFF Research Database (Denmark)

    Richardson, Katherine; Bo Pedersen, Flemming

    1998-01-01

    By coupling knowledge of oceanographic processes and phytoplankton responses to light and nutrient availability, we estimate a total potential new (sensu Dugdale and Goering,1967) production for the North Sea of approximately 15.6 million tons C per year. In a typical year, about 40......% of this production will be associated with the spring bloom in the surface waters of the seasonally stratified (central and northern) North Sea. About 40% is predicted to occur in the coastal waters while the remaining new production is predicted to take place in sub-surface chlorophyll peaks occuring in association...... with fronts in the North Sea during summer month. By considering the inter-annual variation in heat, wind and nutrient availability (light and tidal energy input are treated as non-varying from year to year), the inter-annual variability in the new production occuring in these different regions is estimated...

  10. Critical report of current fisheries management measures implemented for the North Sea mixed demersal fisheries

    DEFF Research Database (Denmark)

    Nielsen, J. Rasmus; Ulrich, Clara; Hegland, Troels J.

    the scientific advice, the development in recent years has been towards this gap being reduced. Management of the fisheries has undergone a number of structural and behavioral changes, and these have already yielded some positive results as the state of the demersal stocks in the North Sea have globally improved......, at least in the prosperous countries around the North Sea, provides only few jobs. Despite the above trends indicating positive effects of the most recent fisheries management of the North Sea mixed demersal fisheries there are a row of general problems in the present management. Population dynamics...... states’ ministers in the Council have exercised strong control over the fisheries management measures which have been developed and adopted on the background of proposals from the Commission and the Parliament, though since the ratification of the Lisbon Treaty the Parliament has assumed a role of co...

  11. Comparative study of air quality by the North Sea and Baltic Sea; Vergleichsuntersuchungen der Luftqualitaet an Nord- und Ostsee

    Energy Technology Data Exchange (ETDEWEB)

    Moriske, H.J.; Turowski, E.; Klar, A.; Schoendube, M.; Ebert, G.; Konieczny, L. [Umweltbundesamt, Berlin (Germany). Inst. fuer Wasser-, Boden- und Lufthygiene

    2000-01-01

    Air quality measurements were carried out in the North Sea and Baltic Sea regions. The results are summarized in this contribution from the hygienic view. [German] Im Rahmen eines Forschungsprojektes des Umweltbundesamtes, das zwischen 1996 und 1998 mit dem Titel 'Erfassung gasfoermiger und partikelfoermiger Bestandteile der Umgebungsluft an Nord- und Ostsee - Untersuchungen zur hygienischen Bedeutung des maritimen Aerosols' durchgefuehrt wurde, sollte die Frage unterschiedlicher Luftqualitaet an Nord- und Ostsee beantwortet werden und eine aktuelle Bestandsaufnahme vorgenommen werden. Der Artikel fasst die Forschungsergebnisse aus hygienischer Sicht zusammen. (orig./SR)

  12. Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)

    DEFF Research Database (Denmark)

    Pham, M.K.; Sanchez-Cabeza, J.A.; Povinec, P.P.

    2006-01-01

    A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (K-40, Cs-137, Th-232, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) were...... ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units. (c) 2006 Elsevier Ltd. All...

  13. The introduction of radionuclides over the atmosphere into the North Sea

    International Nuclear Information System (INIS)

    Kautsky, H.

    1983-01-01

    Although it is barely possible to provide exact data concerning the aerosol entry and the quantities of precipitation in the region of the North Sea, an attempt will be made to estimate the annual entry of radionuclides in the North Sea. As data for the calculations, available estimations of the quantity of precipitation over the sea, the content of radionuclides in the air and in the rain over land and the activities conveyed thereby to the earth, as well as the emission quantities of radionuclides with the exhaust air from nuclear power plants, are applied. It is quite clear that Tritium represents by far the main part of the radionuclides which enter the sea via precipitation. The majority of the other artificial radio nuclides, on the other hand, are to be viewed as being quantitatively insignificant. (orig./HP) [de

  14. Glaciotectonic deformations in the Jammerbugt and glaciodynamic development in the eastern North Sea

    DEFF Research Database (Denmark)

    Pedersen, Stig A. Schack; Boldreel, Lars Ole

    2017-01-01

    –Early Weichselian Skærumhede Group, indicating a Saalian age of the glaciotectonic deformation. The balancing of the thrust fault structures shows that the thrust sheets in the tailing end of the complex had their source in the Skagerrak sea. The hole caused by displacement contributed to formation of the Skagerrak......The Quaternary geology in the eastern part of the North Sea is characterized by large-scale glaciotectonic complexes. The northernmost complex is the Jammerbugt Glaciotectonic Complex here addressed, which occupies an area of more than 300km2. It was recently recognized during an investigation...... of conventional seismic profiles located about 10km offshore the west coast of northern Denmark. The deformed bedrock includes the main part of the Cretaceous Chalk Group in the North Sea. In the northern part of the complex the detachment surface is situated in Lower Cretaceous greensand about 400m below sea...

  15. Historical marine ecology: examining the role of fisheries in changes in North Sea benthos.

    Science.gov (United States)

    Robinson, Leonie A; Frid, Chris L J

    2008-07-01

    The organisms living on and in the sea floor, the benthos, represent an important ecological group. Although some (shellfish) have an economic value, most do not, and so little long-term data are available. We have identified three sources of historic benthic data for the North Sea, a regional sea that has been subjected to multiple human impacts for at least several hundred years. Each dataset has its limitations, but by their use together some issues emerge. Wider community shifts were observed in the shorter term and a number of extirpations at the scale of the North Sea were seen over longer time scales. The extirpated taxa share a number of characteristics consistent with an effect of fisheries such as fragile morphology. We must concentrate now on furthering our understanding of the ecological significance of shifts in dominance of particular functional units and protecting those habitats and species most vulnerable to fisheries-driven extirpation.

  16. Optical measurements in the North Sea-Baltic Sea transition zone. I. On the origin of the deep water in the Kattegat

    Science.gov (United States)

    Højerslev, N. K.; Holt, N.; Aarup, T.

    1996-08-01

    In the North Sea-Baltic Sea region, several studies have shown that yellow substance can be treated as a quasi-conservative parameter that is negatively correlated with salinity. A review of more than 5000 historic and recently gathered yellow substance absorption and salinity measurements from the transition zone between the North Sea and the Baltic Sea have been analyzed for the purpose of water mass identification. Salinity-yellow substance scatter plots show that three water masses can be identified in the area: (1) North Sea water (high salinity, low yellow substance content); (2) Baltic Sea water (low salinity, intermediate-high yellow substance content); and (3) German Bight/Southern North Sea water (intermediate-high salinity, high yellow substance content). Based on the volume flow estimates used in a two-layer box-model of the Kattegat (Jørgensen, Continental Shelf Research, 12, 103-114, 1992) and conservation of yellow substance, it is argued that the long-term average composition of the bottom layer inflow to the Kattegat from the Skagerrak consists of about 90% North Sea/Atlantic water and 10% German Bight/Southern North Sea water. The German Bight content estimate is substantially lower than the ones given in earlier studies (50-67%) and implies that the Jutland Coastal Current only has a small impact on the water quality of the Kattegat.

  17. Bacterial and archaeal communities in sediments of the north Chinese marginal seas.

    Science.gov (United States)

    Liu, Jiwen; Liu, Xiaoshou; Wang, Min; Qiao, Yanlu; Zheng, Yanfen; Zhang, Xiao-Hua

    2015-07-01

    Microbial communities of the Chinese marginal seas have rarely been reported. Here, bacterial and archaeal community structures and abundance in the surface sediment of four sea areas including the Bohai Sea (BS), North Yellow Sea (NYS), South Yellow Sea (SYS), and the north East China Sea (NECS) were surveyed by 16S ribosomal RNA (rRNA) gene pyrosequencing and quantitative PCR. The results showed that microbial communities of the four geographic areas were distinct from each other at the operational taxonomic unit (OTU) level, whereas the microbial communities of the BS, NYS, and SYS were more similar to each other than to the NECS at higher taxonomic levels. Across all samples, Bacteria were numerically dominant relative to Archaea, and among them, Gammaproteobacteria and Euryarchaeota were predominant in the BS, NYS, and SYS, while Deltaproteobacteria and Thaumarchaeota were prevalent in the NECS. The most abundant bacterial genera were putative sulfur oxidizer and sulfate reducer, suggesting that sulfur cycle processes might prevail in these areas, and the high abundance of dsrB (10(7)-10(8) copies g(-1)) in all sites verified the dominance of sulfate reducer in the north Chinese marginal seas. The differences in sediment sources among the sampling areas were potential explanations for the observed microbial community variations. Furthermore, temperature and dissolved oxygen of bottom water were significant environmental factors in determining both bacterial and archaeal communities, whereas chlorophyll a in sediment was significant only in structuring archaeal community. This study presented an outline of benthic microbial communities and provided insights into understanding the biogeochemical cycles in sediments of the north Chinese marginal seas.

  18. Interannual sedimentary effluxes of alkalinity in the southern North Sea: Model results compared with summer observations

    OpenAIRE

    Pätsch, Johannes; Kühn, Wilfried; Six, Katharina D.

    2018-01-01

    For the sediments of the central and southern North Sea different sources of alkalinity generation are quantified by a regional modelling system for the period 2000–2014. For this purpose a formerly global ocean sediment model coupled with a pelagic ecosystem model is adopted to shelf sea dynamics where much larger turnover rates than in the open and deep ocean occurs. To track alkalinity changes due to different nitrogen-related processes the open ocean sediment model was extended by t...

  19. Jurassic and Cretaceous clays of the northern and central North Sea hydrocarbon reservoirs reviewed

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M.; Haszeldine, R.S.; Fallick, A.E.

    2006-03-15

    illite occurs almost ubiquitously within the clastic sediments of the North Sea. An early pore-lining phase has been interpreted as both infiltrated clastic clay, and as an early diagenetic phase. Early clays may have been quite smectite-rich illites, or even discrete smectites. Later, fibrous illite is undoubtedly neoformed, and can degrade reservoir quality significantly. Both within sandstones and shales, there is an apparent increase in the K content deeper than 4 km of burial, which could be due to dilution of the early smectite-rich phase by new growth illite, or to the progressive illitization of existing I-S. Much of the 'illite' that has been dated by the K-Ar method may therefore actually be I-S. The factors that control the formation of fibrous illite are only poorly known, though temperature must play a role. Illite growth has been proposed for almost the entire range of diagenetic temperatures (e.g. 15-20{sup o}C, Brent Group; 35-40{sup o}C, Oxfordian Sand, Inner Moray Firth; 50-90{sup o}C, Brae formation; 100-110{sup o}C, Brent Group; 130-140{sup o}C, Haltenbanken). It seems unlikely that there is a threshold temperature below which illite growth is impossible (or too slow to be significant), though this is a recurring hypothesis in the literature. Instead, illite growth seems to be an event, commonly triggered by oil emplacement or another change in the physiochemical conditions within the sandstone, such as an episode of overpressure release. Hence fibrous illite can grow at any temperature encountered during diagenesis. Although there is an extensive dataset of K-Ar ages of authigenic illites from the Jurassic of the North Sea, there is no consensus as to whether the data are meaningful, or whether the purified illite samples prepared for analysis are so contaminated with detrital phases as to render the age data meaningless. At present it is unclear about how to resolve this problem, though there is some indication that chemical micro

  20. EDXRS study of aerosol composition variations in air masses crossing the North Sea

    International Nuclear Information System (INIS)

    Injuk, J.; Malderen, H. van; Grieken, R. van; Swietlicki, E.; Knox, J.M.; Schofield, R.

    1993-01-01

    X-ray emission techniques for bulk and individual particle analysis (EDXRF, EPXMA, micro-PIXE) were combined and applied in atmospheric research on the North Sea area as part of a field-study on air-sea exchange processes of particulate matter. The atmospheric loading for a number of elements was determined by EDXRF, yielding bulk concentrations for Mg, Al, Si, S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Br and Sr. From these EDXRF data, deposition rates were derived and, based on a classical multivariate statistical approach, different aerosol sources were identified. Complementary to this work, EPXMA combined with automated image analysis was applied to individual size-segregated aerosol particles to determine their inorganic composition, physical size and shape. Also, the first results of micro-PIXE analyses on individual North Sea aerosol particles, particularly their large-size fraction, are discussed and compared with the corresponding EPXMA results. In summary, such a joint approach with the use of different x-ray emission techniques contributed to the resolution of the mixed structure of the lower North Sea troposphere and to the determination of the atmospheric supply of material to the North Sea environment. (author)

  1. The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation.

    Science.gov (United States)

    Campeão, Mariana E; Reis, Luciana; Leomil, Luciana; de Oliveira, Louisi; Otsuki, Koko; Gardinali, Piero; Pelz, Oliver; Valle, Rogerio; Thompson, Fabiano L; Thompson, Cristiane C

    2017-01-01

    One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical-chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae , and Alcanivoracaceae ), archaea (e.g., Halobacteriaceae, Desulfurococcaceae , and Methanobacteriaceae ), and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota) from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web.

  2. The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation

    Directory of Open Access Journals (Sweden)

    Mariana E. Campeão

    2017-06-01

    Full Text Available One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C. We collected deep-sea samples in the field (about 2570 m below the sea surface, transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical–chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae, and Alcanivoracaceae, archaea (e.g., Halobacteriaceae, Desulfurococcaceae, and Methanobacteriaceae, and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web.

  3. Two centuries of observed atmospheric variability and change over the North Sea region

    Science.gov (United States)

    Stendel, Martin; van den Besselaar, Else; Hannachi, Abdel; Kent, Elizabeth; Lefebvre, Christiana; Rosenhagen, Gudrun; Schenk, Frederik; van der Schrier, Gerard; Woollings, Tim

    2016-04-01

    In the upcoming North Sea Region Climate Change Assessment (NOSCCA), we present a synthesis of current knowledge about past, present and possible future climate change in the North Sea region. A climate change assessment from published scientific work has been conducted as a kind of regional IPCC report, and a book has been produced that will be published by Springer in 2016. In the framework of the NOSCCA project, we examine past and present studies of variability and changes in atmospheric variables within the North Sea region over the instrumental period, roughly the past 200 years, based on observations and reanalyses. The variables addressed in this presentation are large-scale circulation, pressure and wind, surface air temperature, precipitation and radiative properties (clouds, solar radiation, and sunshine duration). While air temperature over land, not unexpectedly, has increased everywhere in the North Sea region, with strongest trends in spring and in the north of the region, a precipitation increase has been observed in the north and a decrease in the south of the region. This pattern goes along with a north-eastward shift of storm tracks and is in agreement with climate model projections under enhanced greenhouse gas concentrations. For other variables, it is not obvious which part of the observed changes may be due to anthropogenic activities and which is internally forced. It remains also unclear to what extent atmospheric circulation over the North Sea region is influenced by distant factors, in particular Arctic sea-ice decline in recent decades. There are indications of an increase in the number of deep cyclones (but not in the total number of cyclones), while storminess since the late 19th century shows no robust trends. The persistence of circulation types appears to have increased over the last century, and consequently, there is an indication for 'more extreme' extreme events. However, changes in extreme weather events are difficult to assess

  4. GHRSST Level 4 DMI_OI North Sea and Baltic Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the Danish...

  5. Optimization and kinetic studies of sea mango (Cerbera odollam) oil for biodiesel production via supercritical reaction

    International Nuclear Information System (INIS)

    Ang, Gaik Tin; Ooi, San Nee; Tan, Kok Tat; Lee, Keat Teong; Mohamed, Abdul Rahman

    2015-01-01

    Highlights: • Sea mango oil as feedstock for biodiesel via non-catalytic supercritical reaction. • Extracted sea mango oil with high FFA could produce high yield of FAME. • Employment of Response Surface Methodology for optimization of FAME. • Kinetic study for reversible transesterification and esterification reactions. - Abstract: Sea mango (Cerbera odollam) oil, which is rich in free fatty acids, was utilized to produce fatty acid methyl esters (FAME) via supercritical transesterification reaction. Sea mango oil was extracted from seeds and was subsequently reacted with methanol in a batch-type supercritical reactor. Response surface methodology (RSM) analysis was used to optimize important parameters, including reaction temperature, reaction time and the molar ratio of methanol to oil. The optimum conditions were found as 380 °C, 40 min and 45:1 mol/mol, respectively, to achieve 78% biodiesel content. The first kinetic modelling of FAME production from sea mango oil incorporating reversible transesterification and reversible esterification was verified simultaneously. The kinetic parameters, including reaction rate constants, k, the pre-exponential constant, A, and the activation energy, Ea, for transesterification and esterification were determined using an ordinary differential equation (ODE45) solver. The highest activation energy of 40 kJ/mol and the lowest reaction rate constant of 2.50 × 10 −5 dm 3 /mol s verified that the first stepwise reaction of TG to produce DG was the rate-limiting step

  6. Combining sea state and land subsidence rates in an assessment of flooding hazards at the Danish North Sea coast

    DEFF Research Database (Denmark)

    Sørensen, Carlo Sass; Broge, Niels; Knudsen, Per

    Sand nourishments (2-3 M3/y) counteract erosion on the central North Sea coast of Denmark and dikes and artificial dunes protect the low-lying hinterland from flooding. The fisheries towns of Thyboron, Thorsminde and Hvide Sande are all liable to flooding during storm surges. Tide gauge series fr...... the coast are presented and the town of Thyboron is used as a case where, in addition to SLR and extremes, analyses of land movement and ocean-groundwater interactions are included in an integrated method for assessing future coastal flooding hazards.......Sand nourishments (2-3 M3/y) counteract erosion on the central North Sea coast of Denmark and dikes and artificial dunes protect the low-lying hinterland from flooding. The fisheries towns of Thyboron, Thorsminde and Hvide Sande are all liable to flooding during storm surges. Tide gauge series from...

  7. Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

    OpenAIRE

    Morato, T.; Kvile, K. Ø.; Taranto, G. H.; Tempera, F.; Narayanaswamy, B. E.; Hebbeln, D.; Menezes, G. M.; Wienberg, C.; Santos, R. S.; Pitcher, T. J.

    2013-01-01

    This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic) and in the Medite...

  8. Seamount physiography and biology in North-East Atlantic and Mediterranean Sea

    OpenAIRE

    T. Morato; K. Ø. Kvile; G. H. Taranto; F. Tempera; B. E. Narayanaswamy; D. Hebbeln; G. Menezes; C. Wienberg; R. S. Santos; T. J. Pitcher

    2012-01-01

    This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (North-East Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in-situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (North-East Atlantic) and in Mediterran...

  9. Solar wind: A possible factor driving the interannual sea surface temperature tripolar mode over North Atlantic

    Science.gov (United States)

    Xiao, Ziniu; Li, Delin

    2016-06-01

    The effect of solar wind (SW) on the North Atlantic sea surface temperature (SST) in boreal winter is examined through an analysis of observational data during 1964-2013. The North Atlantic SSTs show a pronounced meridional tripolar pattern in response to solar wind speed (SWS) variations. This pattern is broadly similar to the leading empirical orthogonal function (EOF) mode of interannual variations in the wintertime SSTs over North Atlantic. The time series of this leading EOF mode of SST shows a significant interannual period, which is the same as that of wintertime SWS. This response also appears as a compact north-south seesaw of sea level pressure and a vertical tripolar structure of zonal wind, which simultaneously resembles the North Atlantic Oscillation (NAO) in the overlying atmosphere. As compared with the typical low SWS winters, during the typical high SWS winters, the stratospheric polar night jet (PNJ) is evidently enhanced and extends from the stratosphere to the troposphere, even down to the North Atlantic Ocean surface. Notably, the North Atlantic Ocean is an exclusive region in which the SW signal spreads downward from the stratosphere to the troposphere. Thus, it seems that the SW is a possible factor for this North Atlantic SST tripolar mode. The dynamical process of stratosphere-troposphere coupling, together with the global atmospheric electric circuit-cloud microphysical process, probably accounts for the particular downward propagation of the SW signal.

  10. Evaluation of sea otter capture after the Exxon Valdez oil spill, Prince William Sound, Alaska

    Science.gov (United States)

    Bodkin, James L.; Weltz, F.; Bayha, Keith; Kormendy, Jennifer

    1990-01-01

    After the T/V Exxon Valdez oil spill into Prince William Sound, the U.S. Fish and Wildlife Service and Exxon Company, U.S.A., began rescuing sea otters (Enhydra lutris). The primary objective of this operation was to capture live, oiled sea otters for cleaning and rehabilitation. Between 30 March and 29 May 1989, 139 live sea otters were captured in the sound and transported to rehabilitation centers in Valdez, Alaska. Within the first 15 days of capture operations, 122 (88%) otters were captured. Most sea otters were captured near Knight, Green, and Evans islands in the western sound. The primary capture method consisted of dipnetting otters out of water and off beaches. While capture rates declined over time, survival of captured otters increased as the interval from spill date to capture date increased. The relative degree of oiling observed for each otter captured declined over time. Declining capture rates led to the use of tangle nets. The evidence suggests the greatest threat to sea otters in Prince William Sound occurred within the first 3 weeks after the spill. Thus, in the future, the authors believe rescue efforts should begin as soon as possible after an oil spill in sea otter habitat. Further, preemptive capture and relocation of sea otters in Prince William Sound may have increased the number of otters that could have survived this event.

  11. Remarks on the sea level records of the north Indian ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    variability in the tide gauge records along the coasts of the north Indian Ocean A. S. Unnikrishnan National Institute of Oceanography, Dona Paula, Goa, India 403004 e-mail: unni@nio.org Introduction Global sea-level rise has been relatively well... studied by making use of the coastal tide gauge data that are available (Woodworth and Player, 2003) through the Permanent Service for Mean Sea Level (PSMSL). However, studies on regional sea level rise have not gathered momentum, similar to those on a...

  12. Variability and Dynamics of Dissolved Oxygen in the Transition Zone of the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Jonasson, Lars

    information about the seasonal to decadal oxygen variations in the bottom water of the Kattegat, the Danish Straits, the Sound and the Western Baltic Sea and investigates the relative importance of physical and biogeochemical processes, climate change and nutrient load reductions on the oxygen variability......The bottom water in the transition zone of the North Sea and Baltic Sea suffers from seasonal hypoxia, usually during late summer and autumn. Hypoxia is a natural phenomenon in this region because of the strong vertical stratification which prevents the bottom water to be ventilated by atmospheric...... concentrations by 15-30 μmol O2 l−1 yr−1 while the reduced nutrient concentration has increased the oxygen concentration with approximately the same amount. Thus, the positive effect on oxygen conditions from reduced nutrient concentrations have been counteracted by increased water temperatures. This has made...

  13. Tracking an Oil Tanker Collision and Spilled Oils in the East China Sea Using Multisensor Day and Night Satellite Imagery

    Science.gov (United States)

    Sun, Shaojie; Lu, Yingcheng; Liu, Yongxue; Wang, Mengqiu; Hu, Chuanmin

    2018-04-01

    Satellite remote sensing is well known to play a critical role in monitoring marine accidents such as oil spills, yet the recent SANCHI oil tanker collision event in January 2018 in the East China Sea indicates that traditional techniques using synthetic aperture radar or daytime optical imagery could not provide timely and adequate coverage. In this study, we show the unprecedented value of Visible Infrared Imaging Radiometer Suite (VIIRS) Nightfire product and Day/Night Band data in tracking the oil tanker's drifting pathway and locations when all other means are not as effective for the same purpose. Such pathway and locations can also be reproduced with a numerical model, with root-mean-square error of days of the tanker's sinking reveals much larger oil spill area (>350 km2) than previous reports, the impact of the spilled condensate oil on the marine environment requires further research.

  14. Effort allocation of the Dutch beam trawl fleet in response to a temporarily closed area in the North Sea

    NARCIS (Netherlands)

    Rijnsdorp, A.D.; Piet, G.J.; Poos, J.J.

    2001-01-01

    The spawning stock of North Sea cod is at a historic low level and immediate management measures are needed to improve this situation. As a first step, the European Commission in 2001 closed a large area in the North Sea between February 15 and April 30 to all cod related fishing fleets in order to

  15. The occurrence of the Flying Fish, Hirundichthys speculiger (Valenciennes, 1847), in the North Sea (Pisces, Atheriniformes, Exocoetidae)

    NARCIS (Netherlands)

    Boer, P.; Nijssen, H.

    1972-01-01

    The occurrence of a specimen of the Flying Fish Hirundichthys speculiger (Valenciennes, 1847) in the North Sea is recorded. This is the first record of a member of the family Exocoetidae in the coastal waters of the Netherlands. The specimen is illustrated, and its occurrence in the North Sea is

  16. North Sea Scyphomedusae; summer distribution, estimated biomass and significance particularly for 0-group Gadoid fish

    Science.gov (United States)

    Hay, S. J.; Hislop, J. R. G.; Shanks, A. M.

    Data on the by-catch of Scyphomedusae from pelagic trawls was collected during the routine ICES International 0-group Gadoid Surveys of the North Sea, in June and July of the years 1971-1986 (except 1984). These data are used to describe the distributions, abundances and biomasses of three common North Sea Scyphomedusae: Aurelia aurita (L.), Cyanea capillata (L.) and C. lamarckii (Péron & Lesuer). Information is also presented on inter-annual variability, size (umbrella diameter) frequencies and, for the Cyanea species, umbrella diameter: wet weight relationships. The general role and ecological significance of Scyphomedusae is discussed and, given the well known 'shelter' relationships between Scyphomedusae and certain 0-group fish, whiting ( Merlangius merlangus) and haddock ( Melanogrammus aeglefinus), in particular. The data were examined for evidence of such relationships. Aurelia aurita, although fairly widespread in the northern North Sea was virtually absent from the central North Sea but very abundant in coastal waters. This species was particularly abundant off the Scottish east coast and especially in the Moray Firth. Cyanea lamerckii was most abundant in the southern and eastern North Sea. More widespread than Aurelia, this species was also most abundant in coastal regions, particularly off the Danish west coast. Cyanea capillata, with a more northern distribution was also more widely distributed and abundant offshore. This species was most abundant in the area between the Orkney/Shetland Isles and the Norwegian Deep and in shelf waters of the north west approaches to the North Sea. As with C. lamarckii it was also, in some years, abundant off the Scottish east coast and west of Denmark. The abundance and the size frequency of the jellyfish show considerable inter-annual variability, and variability between regions of the North Sea. It is considered that hydrographic variability and differences in food supply to both medusae and to their sessile

  17. @iMaersk navigator@@ oil spill in the great channel (Andaman Sea) in January 1993 and its environmental impact

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Fondekar, S.P.; Shailaja, M.S.; Sankaranarayanan, V.N.

    Observations on oil slicks, tar residues and dissolved petroleum hydrocarbons (DPH) shortly after the oil spill resulting from the tanker accident in January 1993 showed negligible impact on the Indian EEZ of the Great Channel (Andaman Sea). DPH...

  18. Maersk navigator oil spill in the great channel (Andaman Sea) in January 1993 and its environmental impact

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Fondekar, S.P.; Shailaja, M.S.; Sankaranarayanan, V.N.

    Observations on oil slicks, tar residues and dissolved petroleum hydrocarbons (DPH) shortly after the oil spill resulting from the tanker accident in January 1993 showed negligible impact on the Indian EEZ of the Great Channel (Andaman Sea). DPH...

  19. Elements of seismic imaging and velocity analysis – Forward modeling and diffraction analysis of conventional seismic data from the North Sea

    DEFF Research Database (Denmark)

    Montazeri, Mahboubeh

    2018-01-01

    comprises important oil and gas reservoirs. By application of well-established conventional velocity analysis methods and high-quality diffraction imaging techniques, this study aims to increase the resolution and the image quality of the seismic data. In order to analyze seismic wave propagation......-outs and salt delineations, which can be extracted from the diffractions. The potential of diffraction imaging techniques was studied for 2D seismic stacked data from the North Sea. In this approach, the applied plane-wave destruction method was successful in order to suppress the reflections from the stacked....... This improved seismic imaging is demonstrated for a salt structure as well as for Overpressured Shale structures and the Top Chalk of the North Sea....

  20. Rapid Response of Eastern Mediterranean Deep Sea Microbial Communities to Oil

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiang; Techtmann, Stephen M.; Woo, Hannah L.; Ning, Daliang; Fortney, Julian L.; Hazen, Terry C.

    2017-07-18

    Deep marine oil spills like the Deepwater Horizon (DWH) in the Gulf of Mexico have the potential to drastically impact marine systems. Crude oil contamination in marine systems remains a concern, especially for countries around the Mediterranean Sea with off shore oil production. The goal of this study was to investigate the response of indigenous microbial communities to crude oil in the deep Eastern Mediterranean Sea (E. Med.) water column and to minimize potential bias associated with storage and shifts in microbial community structure from sample storage. 16S rRNA amplicon sequencing was combined with GeoChip metagenomic analysis to monitor the microbial community changes to the crude oil and dispersant in on-ship microcosms set up immediately after water collection. After 3 days of incubation at 14 °C, the microbial communities from two different water depths: 824 m and 1210 m became dominated by well-known oil degrading bacteria. The archaeal population and the overall microbial community diversity drastically decreased. Similarly, GeoChip metagenomic analysis revealed a tremendous enrichment of genes related to oil biodegradation, which was consistent with the results from the DWH oil spill. These results highlight a rapid microbial adaption to oil contamination in the deep E. Med., and indicate strong oil biodegradation potentia

  1. Across the North Sea : The impact of the Dutch Republic

    NARCIS (Netherlands)

    Lottum, J.-J. van

    2007-01-01

    For a long time the early modern population of North Western Europe has been looked upon as fairly sedentary. Although since the 1980s new research has shown that people were much more mobile than was earlier acknowledged, in many historical works either the industrial revolution or the Napoleonic

  2. Multidisciplinary oil spill modeling to protect coastal communities and the environment of the Eastern Mediterranean Sea

    Science.gov (United States)

    Alves, Tiago M.; Kokinou, Eleni; Zodiatis, George; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2016-11-01

    We present new mathematical and geological models to assist civil protection authorities in the mitigation of potential oil spill accidents in the Eastern Mediterranean Sea. Oil spill simulations for 19 existing offshore wells were carried out based on novel and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The simulations show a trend for east and northeast movement of oil spills into the Levantine Basin, affecting the coastal areas of Israel, Lebanon and Syria. Oil slicks will reach the coast in 1 to 20 days, driven by the action of the winds, currents and waves. By applying a qualitative analysis, seabed morphology is for the first time related to the direction of the oil slick expansion, as it is able to alter the movement of sea currents. Specifically, the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. This work suggests that oil spills in the Eastern Mediterranean Sea should be mitigated in the very few hours after their onset, and before wind and currents disperse them. We explain that protocols should be prioritized between neighboring countries to mitigate any oil spills.

  3. Modeling and detection of oil in sea water

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

    2013-01-01

    The challenge of a deep-water oil leak is that a significant quantity of oil remains in the water column and possibly changes properties. There is a need to quantify the oil settled within the water column and determine its physical properties to assist in the oil recovery. There are currently...... for inference of spatial covariance parameters is proposed to describe the scattering field in terms of its second-order statistics from the backscattered returns. The results indicate that high-frequency acoustic methods not only are suitable for large-scale detection of oil contamination in the water column...

  4. Are white-beaked dolphins Lagenorhynchus albirostris food specialst? Their diet in the southern North Sea

    NARCIS (Netherlands)

    Jansen, O.E.; Leopold, M.F.; Meesters, H.W.G.; Smeenk, C.

    2010-01-01

    The white-beaked dolphin Lagenorhynchus albirostris is the most numerous cetacean after the harbour porpoise Phocoena phocoena in the North Sea, including Dutch coastal waters. In this study, the diet of 45 white-beaked dolphins stranded on the Dutch coast between 1968 and 2005 was determined by

  5. Aerosol properties over the Arabian Sea during the north east monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Dulac, F; Leon, G.F; Desa, E.

    440, 670, 870, 936, 940 and 1020 mm, in the Arabian Sea between 15.4-17.86 degrees N and 73.28-69.3 degrees E, during the North East monsoon period of 1-10 December, 1998. The aerosol optical properties derived from these data showed variations from...

  6. Changes in pollution load and environmental trends in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Pawlak, Janet

    1998-12-01

    This publication relates to the quality of the marine environment in the North Sea. Changes in pollution load and environmental trends are analysed. Main themes discussed cover chemical contaminants, temporal trends contaminants in biota, inputs of contaminants to the marine environment, and biological effects of contaminants and biological monitoring. 14 refs., 5 figs., 4 tabs.

  7. Towards harmonised assessment and classification of "biodiversity status" in the North Sea eco-region

    DEFF Research Database (Denmark)

    Skov, H.; Andersen, Jesper; Vinther, M.

    As one of the milestones in the HARMONY-project a demonstration of the application of the integrative indicator based biodiversity assessment tool (BEAT) was undertaken for the Greater North Sea sub-region across a range of coastal and offshore areas. The first version of the BEAT tool was applie...

  8. The south-eastern North Sea : losses of vertebrate fauna during the past 2000 years

    NARCIS (Netherlands)

    Wolff, W.J.

    At least 31 species of marine mammals, marine and coastal birds, and marine and anadromous fish have disappeared temporarily or permanently from the coasts of The Netherlands and in most cases also from the south-eastern North Sea (south of 54 degrees N) during the past 2000 years-In 18-22 cases,

  9. Thermoluminescence dating of abyssal deposits in the north region of the South China Sea

    International Nuclear Information System (INIS)

    Peng Xiaoxian

    1988-01-01

    The ages of abyssal deposits have been studied by TL dating. The ages of the deposits from the wells Weima 1, 5 and 6 at the slope in the north of the South China Sea are 36,100 and 128 thousand years respectively

  10. Trophic impact of Atlantic bluefin tuna migrations in the North Sea

    DEFF Research Database (Denmark)

    Mariani, Patrizio; Andersen, Ken Haste; Lindegren, Martin

    2017-01-01

    and the stability of the fish community. The impact of a migrating top-predator is investigated here for Atlantic bluefin tuna in the North Sea. Bluefin tuna has been absent from the region for half-century, but recent years have seen recovery of migrations and a return of bluefin tuna in the area. We use a size...

  11. Simulated wind-generated inertial oscillations compared to current measurements in the northern North Sea

    Science.gov (United States)

    Bruserud, Kjersti; Haver, Sverre; Myrhaug, Dag

    2018-04-01

    Measured current speed data show that episodes of wind-generated inertial oscillations dominate the current conditions in parts of the northern North Sea. In order to acquire current data of sufficient duration for robust estimation of joint metocean design conditions, such as wind, waves, and currents, a simple model for episodes of wind-generated inertial oscillations is adapted for the northern North Sea. The model is validated with and compared against measured current data at one location in the northern North Sea and found to reproduce the measured maximum current speed in each episode with considerable accuracy. The comparison is further improved when a small general background current is added to the simulated maximum current speeds. Extreme values of measured and simulated current speed are estimated and found to compare well. To assess the robustness of the model and the sensitivity of current conditions from location to location, the validated model is applied at three other locations in the northern North Sea. In general, the simulated maximum current speeds are smaller than the measured, suggesting that wind-generated inertial oscillations are not as prominent at these locations and that other current conditions may be governing. Further analysis of the simulated current speed and joint distribution of wind, waves, and currents for design of offshore structures will be presented in a separate paper.

  12. Amino acids and hexosamines as indicators of organic matter degradation state in North Sea sediments

    NARCIS (Netherlands)

    Dauwe, B.; Middelburg, J.J.

    1998-01-01

    Sediment cores from six stations in the eastern North Sea were analyzed for protein amino acids, the nonprotein amino acids beta-alanine and gamma-aminobutyric acid and the hexosamines galactosamine and glucosamine, and bulk parameters (organic carbon, nitrogen, total hydrolyzable amino acids and

  13. Differential growth of larval sprat Sprattus sprattus across a tidal front in the eastern North Sea

    DEFF Research Database (Denmark)

    Munk, Peter

    1993-01-01

    Spatial variations in abundance and growth of larval sprat Sprattus sprattus L. were examined across a tidal front in the eastern North Sea, off the west coast of Denmark. The aim of the study was to evaluate the potential advantage for sprat larvae of residing in the vicinity of a tidal front...

  14. PHYTOPLANKTON OF THE NORTH-SEA AND ITS DYNAMICS - A REVIEW

    NARCIS (Netherlands)

    REID, PC; LANCELOT, C; GIESKES, WWC; HAGMEIER, E; WEICHART, G

    1990-01-01

    Phytoplankton is the major contributor to algal biomass and primary production of the North Sea, although crops of macroalgae can locally be up to 2000 g C.m-2 along the coast of the U.K. and Norway, and microphytobenthos dominates production in the shallow tidal flat areas bordering the coasts of

  15. Changes in the North Sea fish community: evidence of indirect effects of fishing?

    NARCIS (Netherlands)

    Daan, N.; Gislason, H.; Pope, J.G.; Rice, J.C.

    2005-01-01

    We investigate changes in the North Sea fish community with particular reference to possible indirect effects of fishing, mediated through the ecosystem. In the past, long-term changes in the slope of size spectra of research vessel catches have been related to changes in fishing effort, but such

  16. Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea

    NARCIS (Netherlands)

    Franeker, van J.A.; Blaize, C.; Danielsen, J.

    2011-01-01

    The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of

  17. Comparison between predicted and observed sand waves and sand banks in the North Sea

    NARCIS (Netherlands)

    Hulscher, Suzanne J.M.H.; van den Brink, G.M.

    2001-01-01

    For the first time a prediction model of regular morphological patterns on the seabed was tested against observations of sand wave and sand bank occurrence in the entire North Sea. The model, which originates from first physical principles, predicts this occurrence via two dimensionless parameters

  18. Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    T. Morato

    2013-05-01

    Full Text Available This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic and in the Mediterranean Sea is large with around 557 and 101 seamount-like features, respectively. Similarly, seamounts occupy large areas of about 616 000 km2 in the OSPAR region and of about 89 500 km2 in the Mediterranean Sea. The presence of seamounts in the north-east Atlantic has been known since the late 19th century, but overall knowledge regarding seamount ecology and geology is still relatively poor. Only 37 seamounts in the OSPAR area (3.5% of all seamounts in the region, 22 in the Mediterranean Sea (9.2% of all seamounts in the region and 25 in the north-east Atlantic south of the OSPAR area have in situ information. Seamounts mapped in both areas are in general very heterogeneous, showing diverse geophysical characteristics. These differences will likely affect the biological diversity and production of resident and associated organisms.

  19. EPXMA survey of shelf sediments (Southern Bight, North Sea): A glance beyond the XRD-invisible

    NARCIS (Netherlands)

    De Maeyer-Worobiec, A.; Dekov, V.M.; Laane, R.W.P.M.; van Grieken, R.

    2009-01-01

    Shelf sediments of the southern North Sea, were studied with a microanalytical [electron probe X-ray microanalysis (EPXMA)] and two bulk [X-ray diffraction (XRD) and X-ray fluorescence (XRF)] techniques. The investigation proved that the promptness of the microanalytical method is combined with a

  20. The environmental impact and recovery at two dumping sites for dredged material in the North Sea

    NARCIS (Netherlands)

    Stronkhorst, J.; Ariese, F.; Hattum, van B.; Postma, J.F.; Kluijver, de M.; Besten, den P.; Bergman, M.J.N.; Daan, R.; Murk, A.J.; Vethaak, A.D.

    2003-01-01

    The environmental impact and recovery associated with the long and uninterrupted disposal of large volumes of moderately contaminated dredged material from the port of Rotterdam was studied at nearby dumping sites in the North Sea. Observations were made on sediment contamination, ecotoxicity,

  1. PHYTOPLANKTON OF THE NORTH-SEA AND ITS DYNAMICS - A REVIEW

    NARCIS (Netherlands)

    REID, PC; LANCELOT, C; GIESKES, WWC; HAGMEIER, E; WEICHART, G

    Phytoplankton is the major contributor to algal biomass and primary production of the North Sea, although crops of macroalgae can locally be up to 2000 g C.m-2 along the coast of the U.K. and Norway, and microphytobenthos dominates production in the shallow tidal flat areas bordering the coasts of

  2. Fulmar Litter EcoQO monitoring along Durch and North Sea coasts

    NARCIS (Netherlands)

    Franeker, van J.A.

    2011-01-01

    Wastes from ships are an important source of litter in the marine environment in the Southern North Sea and cause serious economic and ecological damage. Inadequacies in the ship to shore waste delivery procedures are considered a major factor in illegal discharges. The European Union addressed the

  3. Dissolved organic nitrogen dynamics in the North Sea: A time series analysis (1995-2005)

    NARCIS (Netherlands)

    Van Engeland, T.; Soetaert, K.E.R.; Knuijt, A.; Laane, R.W.P.M.; Middelburg, J.J.

    2010-01-01

    Dissolved organic nitrogen (DON) dynamics in the North Sea was explored by means of long-term time series of nitrogen parameters from the Dutch national monitoring program. Generally, the data quality was good with little missing data points. Different imputation methods were used to verify the

  4. Detection of low numbers of microplastics in North Sea fish using strict quality assurance criteria

    NARCIS (Netherlands)

    Hermsen, E.; Pompe, R.; Besseling, E.; Koelmans, A.A.

    2017-01-01

    We investigated 400 individual fish of four North Sea species: Atlantic Herring, Sprat, Common Dab, and Whiting on ingestion of > 20 μm microplastic. Strict quality assurance criteria were followed in order to control contamination during the study. Two plastic particles were found in only 1 (a

  5. Radiological implications from the temporal development of radioactivity in marine food from the North Sea

    International Nuclear Information System (INIS)

    Kanisch, G.; Nagel, G.; Krueger, A.; Kellermann, H.-J.

    2000-01-01

    A subject of the revision of authorised limits in 1994 for the discharge of liquid radioactive waste by the reprocessing plant Sellafield (UK) was an increase of these limits for certain radionuclides ( 3 H, 14 C, 60 Co, 99 Tc and 129 I). It is investigated now how the radioactivity in marine biota from the North Sea and subsequently the public radiation exposure of seafood consumers has developed in the years since 1994. This is based on a compartment model for dispersion in the North-East Atlantic. Discharges from the reprocessing plants Dounreay (UK) and La Hague (F) are included in the assessment. It is deduced that about 60% of 137 Cs in the North Sea originate presently in the remobilisation of old Sellafield discharges from the Irish Sea sediment. A comparison with measured biota data shows that the model is conservative in most cases. The public radiation exposure (artificial radionuclides) from ingestion of fish, crustaceans and molluscs from the central North Sea as the sum over 12 considered radionuclides has decreased from 1992 to 1998 from 0.13 to 0.08 μSv y -1 . (orig.)

  6. Orbital calibration of the late Campanian carbon isotope event in the North Sea

    DEFF Research Database (Denmark)

    Perdiou, Anastasios; Thibault, Nicolas; Anderskouv, Kresten

    2016-01-01

    A new record of carbon isotopes, nannofossil biostratigraphy, gamma-ray and Fe content variations is presented for the upper Campanian of the Adda-3 core, Danish Central Graben, North Sea. The studied interval provides a revision of previously assigned late Coniacian to early Santonian ages. New...

  7. Temperature affects the timing of spawning and migration of North Sea mackerel

    DEFF Research Database (Denmark)

    Jansen, Teunis; Gislason, Henrik

    2011-01-01

    Climate change accentuates the need for knowing how temperature impacts the life history and productivity of economically and ecologically important species of fish. We examine the influence of temperature on the timing of the spawning and migrations of North Sea Mackerel using data from larvae C...

  8. Importance of ocean circulation in ecological modeling: An example from the North Sea

    Science.gov (United States)

    Skogen, Morten D.; Moll, Andreas

    2005-09-01

    There is an increasing number of ecological models for the North Sea around. Skogen and Moll (2000) [Skogen, M.D., Moll, A. 2000. Interannual variability of the North Sea primary production: comparison from two model studies. Continental Shelf Research 20 (2), 129-151] compared the interannual variability of the North Sea primary production using two state-of-the-art ecological models, NORWECOM and ECOHAM1. Their conclusion was that the two models agreed on an annual mean primary production, its variability and the timing and size of the peak production. On the other hand, there was a low (even negative dependent of area) correlation in the production in different years between the two models. In the present work, these conclusions are brought further. To try to better understand the observed differences between the two models, the two ecological models are run in an identical physical setting. With such a set-up also the interannual variability between the two models is in agreement, and it is concluded that the single most important factor for a reliable modeling of phytoplankton and nutrient distributions and transports within the North Sea is a proper physical model.

  9. Eleven bones: More fossil remains of Cave Lions and Cave Hyaenas from the North Sea area

    NARCIS (Netherlands)

    Bosscha Erdbrink, D.P.

    1983-01-01

    Six fossil Cave Lion bones and five fossil Cave Hyaena bones are described. One lion bone and one hyaena bone were dredged from the Westerschelde ( = Western Scheldt, southwestern part of the Netherlands). The other specimens were recovered from the bottom of the North Sea, in the area West and

  10. Description of the North Sea wind climate for wind energy applications

    NARCIS (Netherlands)

    Coelingh, J.P.; Wijk, A.J.M. van; Cleijne, J.W.; Pleune, R.

    1992-01-01

    In The Netherlands it is foreseen that wind turbines will be installed on offshore locations in the North Sea before the year 2010. Therefore adequate knowledge of the offshore wind climate should be obtained, both for the estimation of energy yields and for the determination of wind load

  11. Recent increase of North Sea houting and prospects for recolonization in the Netherlands

    NARCIS (Netherlands)

    Kranenbarg, J.; Winter, H.V.; Backx, J.J.G.M.

    2002-01-01

    Two monitoring programmes in estuarine and freshwater systems in the Netherlands both show a recent increase in anadromous North Sea houting Coregonus oxyrhynchus after it disappeared there in the 1940s. Most houting were immature and caught during the feeding season indicating that at present the

  12. Observations of copepod feeding and vertical distribution under natural turbulent conditions in the North Sea

    DEFF Research Database (Denmark)

    Visser, Andre; Saito, H.; Saiz, E.

    2001-01-01

    We present results of simultaneous measurements of turbulent- dissipation rate, zooplankton vertical distribution and copepod gut pigments in the northern North Sea. Analysis shows that some, but not all, copepods (by species, sex and stage) exhibit significant dependence on turbulence in respect...

  13. Dual hydraulic behaviour of the Chalk in the Netherlands North Sea

    NARCIS (Netherlands)

    Verweij, H.

    2006-01-01

    Information on the sedimentary development, seismic stratigraphy and burial compaction of the Chalk Group in the Netherlands North Sea was combined with pressure data and basin modelling to investigate the hydraulic behaviour of the Chalk Group in the Central Graben and Schill Grund High. The

  14. Mapping the spawning grounds of North Sea cod ( Gadus morhua ) by direct and indirect means

    DEFF Research Database (Denmark)

    Fox, C.J.; Taylor, M.; Dickey-Collas, M.

    2008-01-01

    Despite recent evidence for sub-stock structuring, North Sea cod are assessed as a single unit. As a consequence, knowledge of sub-stock trends is poor. In particular, there are no recent evaluations of which spawning grounds are active. Here we report results from the first ichthyoplankton survey...

  15. Mapping the spawning grounds of North Sea cod (Gadus morhua) by direct and indirect means

    NARCIS (Netherlands)

    Fox, C.J.; Taylor, M.; Dickey-Collas, M.; Fossum, P.; Kraus, G.; Rohlf, N.; Damme, van C.J.G.; Bolle, L.J.

    2008-01-01

    Despite recent evidence for sub-stock structuring, North Sea cod are assessed as a single unit. As a consequence, knowledge of sub-stock trends is poor. In particular, there are no recent evaluations of which spawning grounds are active. Here we report results from the first ichthyoplankton survey

  16. A lasting legacy for the Baltic and North Sea GLOBEC Germany program

    DEFF Research Database (Denmark)

    Peck, M.A.; Dutz, Jörg; Voss, R.

    2012-01-01

    This preface introduces four manuscripts that form a special theme section of the GLOBEC Germany program within Progress in Oceanography. The four manuscripts link changes in physical forcing to the trophodynamic structure and function of the Baltic and North Seas. The target species of GLOBEC Ge...... Germany included various species of calanoid copepods and a small pelagic fish (Sprattus sprattus)...

  17. Benthic nutrient cycling and diagenetic pathways in the North-western Black Sea

    NARCIS (Netherlands)

    Friedrich, J.; Dinkel, C.; Friedl, G.; Pimenov, N.; Wijsman, J.W.M.; Gomoiu, M-T.; Cociasu, A.; Popa, L.; Wehrli, B.

    2002-01-01

    Benthic fluxes of nutrients and metals were measured in the coastal zone of the north-western Black Sea, which is influenced by the Danube and Dniestr rivers. The results from the benthic flux chambers deployed during two EROS 21 cruises in summer 1995 and in spring 1997 yield information on benthic

  18. Covariance among North Sea nutrient and climate drivers: consequences for plankton dynamics.

    NARCIS (Netherlands)

    McQuatters-Gollop, A.; Vermaat, J.E.

    2011-01-01

    Regime shift and principal component analysis of a spatially disaggregated database capturing time-series of climatic, nutrient and plankton variables in the North Sea revealed considerable covariance between groups of ecosystem indicators. Plankton and climate time-series span the period 1958-2003,

  19. Temporal changes in plankton of the North Sea: community shfits and environmental drivers

    NARCIS (Netherlands)

    Alvarez-Fernandez, S.; Lindeboom, H.J.; Meesters, H.W.G.

    2012-01-01

    This paper analyses long-term and seasonal changes in the North Sea plankton community during the period 1970 to 2008. Based on Continuous Plankton Recorder (CPR) data covering 38 yr, major changes in both phytoplankton and zooplankton abundance and community structure were identified. Regime

  20. Quantification of seep-related methane gas emissions at Tommeliten, North Sea

    NARCIS (Netherlands)

    Schneider von Deimling, J.S.; Rehder, G.; Greinert, J.; McGinnnis, D.F.; Boetius, A.; Linke, P.

    2011-01-01

    Tommeliten is a prominent methane seep area in the Central North Sea. Previous surveys revealed shallow gas-bearing sediments and methane gas ebullition into the water column. In this study, the in situ methane flux at Tommeliten is re-assessed and the potential methane transport to the atmosphere

  1. Effects of ocean acidification on primary production in a coastal North Sea phytoplankton community

    NARCIS (Netherlands)

    Eberlein, Tim; Wohlrab, Sylke; Rost, Björn; John, Uwe; Bach, Lennart T.; Riebesell, U.; Van de Waal, D.B.

    2017-01-01

    We studied the effect of ocean acidification (OA) on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study). From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar

  2. Lithostratigraphy of the Palaeogene - Lower Neogene succession of the Danish North Sea

    DEFF Research Database (Denmark)

    Schiøler, Poul-Henrik; Andsbjerg, Jan; Clausen, Ole Rønø

    2007-01-01

    sediments of the Danish sector of the North Sea is revised. The sediment package from the top of the Chalk Group to the base of the Nordland Group is subdivided into seven formations containing eleven new members. The existing Våle, Lista, Sele, Fur, Balder, Horda and Lark Formations of previously...

  3. Tracing estuarine organic matter sources into the southern North Sea using C and N isotopic signatures

    DEFF Research Database (Denmark)

    Bristow, Laura A.; Jickells, Timothy D.; Weston, Keith

    2013-01-01

    Sources and distribution of particulate organic matter in surface waters of the Humber and Thames estuaries and in the East Anglian plume in the southern North Sea were investigated in winter 2006/2007. Carbon (C) and nitrogen (N) stable isotopes provided evidence for the presence of three partic...

  4. Developments in the North Sea and their consequences for the marine environment

    NARCIS (Netherlands)

    Eisma, D.

    1981-01-01

    Summarizing, the marine environment of the North Sea is threatened in several ways: by waterpollution, by overfishing and by bottom disturbance. Fishing is now extremely regulated, but research on and control of stocks is only extended to commercial species. Strict regulations have been made for

  5. Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size?

    DEFF Research Database (Denmark)

    Rindorf, Anna; Andersen, Bo Sølgaard

    2008-01-01

    This study presents all investigation of the relationship between stock size of North Sea cod (Gadus morhua) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a model allowing both density-dependent changes in catchability and bias...

  6. Critical report of current fisheries management measures implemented for the North Sea mixed demersal fisheries

    DEFF Research Database (Denmark)

    Nielsen, J. Rasmus; Ulrich, Clara; Hegland, Troels J.

    The present report is an EU-FP7-SOCIOEC Report giving an overview and critical evaluation of the current management measures implemented for the North Sea mixed demersal fisheries and the fish stocks involved in this. Also, this involves review and critical evaluation of the scientific advice...

  7. Development of north sea coastal plankton communities in separate plastic bags under identical conditions

    NARCIS (Netherlands)

    Kuiper, J.

    1977-01-01

    In two experiments lasting 4 to 6 weeks, communities of North Sea coastal plankton kept in separate plastic bags (of about 1400 l) and exposed to the same environmental conditions showed very similar patterns of growth and decline. This result means that the method is suitable for the evaluation of

  8. Floc size and aspects of flocculation processes of suspended particulate matter in the North Sea area

    NARCIS (Netherlands)

    Chen, S.

    1995-01-01

    Investigations on the size of suspended particulate matter in the North Sea and two adjacent estuaries were carried out using an in situ technique: image analysis of photographs from an underwater camera system. The results obtained from such an in situ method gave a new knowledge on the size

  9. Realized habitats of early-stage North Sea herring: looking for signals of environmental change

    DEFF Research Database (Denmark)

    Röckmann, C.; Dickey-Collas, M.; Payne, Mark

    2011-01-01

    Realized habitats of North Sea herring for two larval and two juvenile stages were estimated over the past 30 years, using abundances from surveys tied to modelled estimates of temperature and salinity. Newly hatched larvae (NHL) were found mainly in water masses of 9–11°C, pre-metamorphosis larvae...

  10. Gas deliveries from Haltenbanken/North Sea; Gassleveranser Haltenbanken/Nordsjoeen

    Energy Technology Data Exchange (ETDEWEB)

    Ramm, H.H.

    1995-12-31

    The conference paper relates to the development and delivery of natural gas from the Haltenbanken area and the North Sea on the Norwegian continental shelf. Alternatives of field developments and pipelines together with the allocation of contracts for securing the contractual delivery of natural gas to the European continent in future and an alternative delivery to the Scandinavian countries, are discussed. 2 figs.

  11. Shifts in North Sea forage fish productivity and potential fisheries yield

    NARCIS (Netherlands)

    Clausen, Lotte W.; Rindorf, Anna; Deurs, van Mikael; Dickey-Collas, Mark; Hintzen, Niels T.

    2018-01-01

    1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature, the

  12. The paleocene in north Africa - Sea-level changes and paleoproductivity in Tunisa, Libya and Egypt using microfossils

    NARCIS (Netherlands)

    Guasti, E.; Lüning, S.

    2009-01-01

    The Paleocene is a time of warm oceans and generally high sea levels. In North Africa, vast epicontinental seas extended far inside the African continent. In this paper we correlate sea level, primary paleoproductivity and facies distribution of the proximal, carbonate-dominated Paleocene deposits

  13. Effects of air-sea coupling over the North Sea and the Baltic Sea on simulated summer precipitation over Central Europe

    Science.gov (United States)

    Ho-Hagemann, Ha Thi Minh; Gröger, Matthias; Rockel, Burkhardt; Zahn, Matthias; Geyer, Beate; Meier, H. E. Markus

    2017-12-01

    This study introduces a new approach to investigate the potential effects of air-sea coupling on simulated precipitation inland over Central Europe. We present an inter-comparison of two regional climate models (RCMs), namely, the COSMO-CLM (hereafter CCLM) and RCA4 models, which are configured for the EURO-CORDEX domain in the coupled and atmosphere-only modes. Two versions of the CCLM model, namely, 4.8 and 5.0, join the inter-comparison being almost two different models while providing pronouncedly different summer precipitation simulations because of many changes in the dynamics and physics of CCLM in version 5.0. The coupling effect on the prominent summer dry bias over Central Europe is analysed using seasonal (JJA) mean statistics for the 30-year period from 1979 to 2009, with a focus on extreme precipitation under specific weather regimes. The weather regimes are compared between the coupled and uncoupled simulations to better understand the mechanism of the coupling effects. The comparisons of the coupled systems with the atmosphere-only models show that coupling clearly reduces the dry bias over Central Europe for CCLM 4.8, which has a large dry summer bias, but not for CCLM 5.0 and RCA4, which have smaller dry biases. This result implies that if the atmosphere-only model already yields reasonable summer precipitation over Central Europe, not much room for improvement exists that can be caused by the air-sea coupling over the North Sea and the Baltic Sea. However, if the atmosphere-only model shows a pronounced summer dry bias because of a lack of moisture transport from the seas into the region, the considered coupling may create an improved simulation of summer precipitation over Central Europe, such as for CCLM 4.8. For the latter, the benefit of coupling varies over the considered timescales. The precipitation simulations that are generated by the coupled system COSTRICE 4.8 and the atmosphere-only CCLM 4.8 are mostly identical for the summer mean

  14. MODELING OF OIL POLLUTION OF ARTIC SEA COASTAL AREAS

    Directory of Open Access Journals (Sweden)

    2017-01-01

    Full Text Available This article studies the elastic filtration oil drive of oil in a layer based on the estimation of risks of environmental oil pollution because of accidental releases. The model of oil spillage and resorption by the precoat is based on continuity equation and Darcy rule as well as on equations of state taking into account fluid compressibility due to pressure. Filtering area is a line between the precoat and air. Oil filtering area is limited by soil surface below and by free surface above, its equation is known beforehand and is to be defined. The case of soil pollution from the point source, which is the point of fracture of pipeline or borehole, is considered. Upper and approximate estimates of the oil pollution radius due to different types of underlying terrains and to oil characteristics as well as to environmental conditions. The dynamics of oil free sur- face depending on spillage radii is calculated and presented. The estimates of temporary duration of oil filtering by the pre- coat in terms of light ends and soil type are made. The thickness of the oil film and the square of the spill upon condition of constant speed of oil spillage, horizontal position of underlying terrain and the proximity of pressure to normal are deter- mined. For the numerical implementation of the model different cases of oil spillage were considered. Under given values of air temperature, soil porosity and filtration speed the pollution radii according to light end, the time from the moment of accident till the leakage suppression and the speed of oil spillage was calculated.

  15. Occurrence of Ergasilus megaceros Wilson, 1916, in the sea lamprey and other fishes from North America

    Science.gov (United States)

    Muzzall, Patrick M.; Hudson, Patrick L.

    2004-01-01

    Ergasilus megaceros (Copepoda: Ergasilidae) was recovered from the nasal fossae (lamellae) of the olfactory sac in 1 (1.8%) of 56 sea lampreys, Petromyzon marinus Linne, 1758, collected in May 2002 from the Cheboygan River, Michigan. Although the sea lamprey is a new host record for E. megaceros, this fish species may not be a preferred host because of its low prevalence. Ergasilus megaceros is the second ergasilid species reported from the sea lamprey in North America. This is the third report of an ergasilid species infecting the nasal fossae of fishes in North America, with E. rhinos being the only other species reported from this site.

  16. North sea: a quarter of total's reserves (excluding the Middle East)

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    In 1994, for the fifth successive year, Total increased its proven reserves of hydrocarbons which reach 4.3 Gboe (+ 6% compared to 1993). Outside the Middle East, the reserves show a development of 9% and reach the threshold of 2 Gboe. In 1994, Total's production of hydrocarbons reached 633,000 boe/d (+ 4%), despite a fall of 3% in oil production in the Middle East. Excluding the Middle East, production was increased to 345,000 boe/d (+ 12%), including 212,000 boe/d for gas (+ 20%). Exploration/production investments were 5.8 GF in 1994 (excluding labour) and the development program for reserves and production for the coming years is based on yearly investments of some 6 GF. Total's production in Europe, essentially in the North Sea, was 154,000 boe/d in 1994 (+ 12%). This zone has potential for significant growth for the group which has undertaken exploration surveys in the Western Shetlands and in Haltenbanken. In the British zone, the Dunbar field and its neighbour Ellon were brought into production in December 1994. In the Norwegian zone, the Froy field, was brought into production last June. In the Lille-Frigg field, whose production started in May, initial reserves are estimated at 6,7 Bcm of gas. Total Norge AS also has interests in the producing fields of Ekofisk, Frigg, East-Frigg, Heimdal, Sleipner East, Veslefrikk, Oseberg, Brage, in those of Sleipner West and Huldra (start-up scheduled for 1997) and in Troll (phase 1) which should be producing in 1996. In the Dutch zone, the K4b and K5a blocks brought into production last November hold reserves estimated at 20 Bcm; their production could reach 2 Bcm/year as from 1995. (authors). 1 tab., 1 photo

  17. Modeling oil spills in the Med-Sea as a mean of early response in cases of oil leakages

    Science.gov (United States)

    Zodiatis, George; De Dominicis, Michela; Perivoliotis, Leonidas; Radhakrishnan, Hari; Lardner, Robin; Pinardi, Nadia; Coppini, Giovanni; Soloviev, Dmitry; Tintore, Joaquin; Sotillo, Marcos; Drago, Aldo; Stylianou, Stavros; Nikolaidis, Andreas; Alves, Tiago; Kokinou, Eleni

    2016-04-01

    Modeling oil spills in the Med-Sea as a mean of early response in cases of oil leakages G. Zodiatis1, M. De Dominicis2, L. Perivoliotis3, H. Radhakrishnan1, R. W. Lardner1, N. Pinardi2, G. Coppini4, D. Soloviev1, J. Tintore5, M. Sotillo6 A. Drago7, S. Stylianou1, A. Nikolaidis1, T. Alves8, E. Kokinou9 and MEDESS4MS partners 1Oceanography Centre, University of Cyprus, Nicosia, Cyprus 2Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy 3Hellenic Center for Marine Research, Athens, Greece 4Centro Euro- Mediterraneo sui Cambiamenti Climatici, Italy 5SOCIB, IMEDEA, Palma de Majorca, Spain 6Puertos del Estado, Madrid, Spain 7IOI, University of Malta, La Valetta, Malta 83D Seismic Lab, School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom 9Dept. of Environmental and Natural Resources, Technological Educational Institute Crete, Chania, Greece The risk from oil spill pollution in the Mediterranean is high due to the heavy traffic of merchant vessels for transporting oil and to the increasing coastal and offshore platforms related to the hydrocarbon exploration. This is especially true in the Levantine Basin following the recent widening of the Suez canal and the increase of the offshore deep wells for the exploitation of oil and gas. In order to select the optimal response measurements to assist the response agencies, oil spill models are used to provide predictions of the drift and weathering of the oil slicks. The establishment of the operational ocean forecasting systems at regional level, within the Copernicus Marine Environmental Monitoring Service and in association with the national downscaled ones, provided the background for the implementation of a multi model integrated oil spill prediction system for the entire Mediterranean to support the maritime safety in near real time. This implementation was carried out in the frame of the medess4ms.eu project, which is dedicated to the response agencies of the riparian countries and to

  18. Evaluation of harvest and information needs for North American sea ducks.

    Science.gov (United States)

    Koneff, Mark D; Zimmerman, Guthrie S; Dwyer, Chris P; Fleming, Kathleen K; Padding, Paul I; Devers, Patrick K; Johnson, Fred A; Runge, Michael C; Roberts, Anthony J

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  19. Structural geology of the North and Middle Caspian sea on the new geophysical data interpretation

    International Nuclear Information System (INIS)

    Boris, V.S; Rais, V.Sh; Victor, L.U

    2002-01-01

    Full text:A structural and tectonic map of the North and Middle Caspian Sea is made on the basis of seismic and other geological and geophysical data analysis. According to the plotting results the total amplitude range of the heterogeneous basement depths are in the North Caspian Sea (Ukatnensky depression-over 12 km and Prorva depression-over 16 km). In the middle Caspian Sea the deppest basement point is supposed in Sulak basin (over 12 km). The least basement depths are marked in Karpinsky ridge,Buzachinky and Karabogazsky arches (1-3 km). On the whole the morphology and structure of the basement confirms the conclusion previously made by many researches that the Caspian Sea is a heterogeneous depression superimposed on the junction of regional tectonic elements of various ages.The ancient East-European platform represented by Pricaspiisky depression (Donetsko-Astrakhanskaya fault system limits the latter in the south) is situated on the North. The middle Caspian Sea is occupied with the offshore continuation of Terek-Caspian foredeep is represented by Sulak basin clearly limited in the south by a system of upthrusts and thrusts falling under North Caucasus foreland.Geological interpretation of the Yuzhmorgeologiya Center new geophysical data allows making an assumption about the biohermexistence within TriassicSea sediments on Kuma-Manychsky depression offshore continuation. Seismic exploration works show strike-slip faults and thrust structure development within the sedimentary cover on the offshore continuation of Karpinsky ridge.Some strike-slipped blocks are separated by left-side shifts of the northeast stretch.The pool location at the left-side (east) blocks of the shift areas is marked.

  20. Clay-oil flocculation during surf washing at the Sea Empress incident

    International Nuclear Information System (INIS)

    Wood, P.; Lunel, T.; Bailey, N.; Lee, K.

    1997-01-01

    Results of investigations into clay-oil flocculation during surf washing of oiled cobbles at Marros Beach, as a response to oiling during the Sea Empress incident, were summarized. Stranded oil on the cobble storm beach was found to associate with fine minerals and form flocs when introduced into sea water. The emulsions persisted for about 14 days after the oiling, after which it begun to disintegrate. After 50 days the remaining emulsion was found to be unstable and penetrated the beach to depths of up to three meters. Since no evidence of biodegradation was found during this period, oil reduction was attributed to sheening, facilitated by tidal fluctuations. Surf washing operation was undertaken over a seven day period beginning 47 days after the spill. Some 8150 tonnes of oiled cobbles were moved a distance of between 12 and 18 m seaward along a length of 850 m. Analysis of samples after two days following surf washing showed that oil concentration did not exceed 22 ppm, compared to 700 ppm before relocation. The significant reduction was considered to have been the result of enhanced oil dispersion coupled with the effects of the surf washing operations. 10 refs., 7 tabs., 10 figs

  1. Arctic Oil Spill Response Guide for the Alaskan Beaufort Sea

    Science.gov (United States)

    1988-03-01

    skimmers. Oiled soil and debris, which could not be cleaned by this technique, was removed and placed in heavy duty plastic bags and 55-gallon drums. 6.5.9...burned in a smokeless flare burner. Oiled debris was burned in the Coast Guard Trecan Incinerator which was set up at Prudhoe Bay. Oiled soil was placed...skeletons that form diatomite . Dinoflagellates: any of an order to planktonic forms important in aquatic food chains and including forms causing red tides

  2. Ecological assessment of oil-gas producing area in Kazakhstan zone of Caspian sea and using the bioremediation technology for cleaning of high level oil polluted sites

    International Nuclear Information System (INIS)

    Bigaliev, A.A.; Ishanova, N.E.; Bijazheva, S.M.; Novikova, A.; Bigaliev, A.B.

    2008-01-01

    A significant part of mineral raw material resources of Kazakhstan placed in the depth of the Caspian region, where more than 90% extracting of oil and natural gas, 100% balance store rare ground, 3.2% uranium, ore 0.3%, 90.5% sawn store concentrated. Last years, it takes intensive works by extraction of carbon raw materials in Kazakhstan sector of the Caspian sea. It brought to exceeding of coastal pollution at the North and middle the Caspian coastal pollution with oil products in average till 0.282 mg/l. Maximum meaning oil product pollution reaches 0.56 mg/l (which means exceeding of limited concentration on 11 times). How much money need to cover cost of remediation in real sites? Develop of assessment and monitoring procedures based on fate mechanisms for most of representative hydrocarbons in polluted soils. Step 1 - Collection of heavily polluted portions of soils, separation of hydrocarbons by cost efficient mechanical procedures and send HC rich material (HC>95%) to prepare of alternative fuel. Return of low HC content sand to project area (HC<5.0%). Step 2 - Development of low cost bioremediation procedures in areas transformed to moderately polluted site (HC<5% after removing of heavily polluted portions) with uniform HC content. We are needed to develop of coast efficiency approach for cleaning of high level oily polluted sites around urban areas in Kazakhstan new methodology to estimate polluted area and recover of pollution history, low cost bioremediation

  3. Transport interests and environmental regimes. The Baltic Sea transit of Russian oil exports

    International Nuclear Information System (INIS)

    Knudsen, Olav F.

    2010-01-01

    In the environmentally exposed Baltic Sea, a prolonged confrontation has set the transport interests of Russian crude oil against environmental interests, promoted by Russia's neighbours. During the 1990s all the Baltic littoral states - including Russia - collaborated well on marine environmental issues. When Russian oil exports accelerated after 1999, this environmental understanding broke down. Russian interests shifted as its oil income suddenly rose drastically. The confrontation peaked over a proposal to make the entire Baltic Sea into a particularly sensitive sea area (PSSA) under the International Maritime Organization (IMO). The proposal was adopted by the IMO in spite of Russian objections. The article shows how environmental interests trump transport interests in a manner that may not be sustainable. The case illustrates the need for environmental collaboration to be flexible in the face of shifting constellations of competing interests. (author)

  4. Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.; Deng, Y.; Nostrand, J.D. Van; He, Z.; Voordeckers, J.; Zhou, A.; Lee, Y.-J.; Mason, O.U.; Dubinsky, E.; Chavarria, K.; Tom, L.; Fortney, J.; Lamendella, R.; Jansson, J.K.; D?haeseleer, P.; Hazen, T.C.; Zhou, J.

    2011-06-15

    The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in U.S. history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared to outside the plume, indicating a great potential for intrinsic bioremediation or natural attenuation in the deep-sea. Various other microbial functional genes relevant to carbon, nitrogen, phosphorus, sulfur and iron cycling, metal resistance, and bacteriophage replication were also enriched in the plume. Together, these results suggest that the indigenous marine microbial communities could play a significant role in biodegradation of oil spills in deep-sea environments.

  5. Life cycle water demand coefficients for crude oil production from five North American locations.

    Science.gov (United States)

    Ali, Babkir; Kumar, Amit

    2017-10-15

    The production of liquid fuels from crude oil requires water. There has been limited focus on the assessment of life cycle water demand footprints for crude oil production and refining. The overall aim of this paper is address this gap. The objective of this research is to develop water demand coefficients over the life cycle of fuels produced from crude oil pathways. Five crude oil fields were selected in the three North American countries to reflect the impact of different spatial locations and technologies on water demand. These include the Alaska North Slope, California's Kern County heavy oil, and Mars in the U.S.; Maya in Mexico; and Bow River heavy oil in Alberta, Canada. A boundary for an assessment of the life cycle water footprint was set to cover the unit operations related to exploration, drilling, extraction, and refining. The recovery technology used to extract crude oil is one of the key determining factors for water demand. The amount of produced water that is re-injected to recover the oil is essential in determining the amount of fresh water that will be required. During the complete life cycle of one barrel of conventional crude oil, 1.71-8.25 barrels of fresh water are consumed and 2.4-9.51 barrels of fresh water are withdrawn. The lowest coefficients are for Bow River heavy oil and the highest coefficients are for Maya crude oil. Of all the unit operations, exploration and drilling require the least fresh water (less than 0.015 barrel of water per barrel of oil produced). A sensitivity analysis was conducted and uncertainty in the estimates was determined. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Oil demand in North America: 1980-2020

    International Nuclear Information System (INIS)

    Ghouri, S.S.

    2001-01-01

    This paper first analyses price and income elasticity of oil demand in the United States, Canada and Mexico for the period 1980-99. Economic activity is the main driving force that influences oil consumption in each country. Changes in oil consumption generally lagged by a few years before the full impact of changes in oil prices was realized. Consumers in the short run are constrained by technological and other barriers and, therefore, less sensitive to changes in oil prices; however, they are more responsive in the long run - though response is still inelastic. The use of advanced technology facilitated these countries to use less oil over time. The paper then looks at demand over the next 20 years. The best-fitting model predicts that, by the end of 2020 (reference case), the USA, Canada and Mexico will respectively consume 24,900, 2,596 and 2,321 thousand barrels daily, compared with 19,519, 1,943 and 1,970 thousand b/d in 1999. The model forecasts economic slowdown during 2000/2002. The USA and Canada are expected to recover quickly, while Mexico will take longer. (author)

  7. RKU North Sea. Update on the regional consequence examination concerning the petroleum industry in the North Sea; RKU-Nordsjoeen. Oppdatering av regional konsekvensutredning for petroleumsvirksomhet i Nordsjoeen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-12-15

    An overview over prognoses for oil and gas production and the emissions related to these activities is provided for the years 2005-2025. A description of the Norwegian Continental Shelf's ecosystem, environmental technology employed, and considerations regarding the petroleum industry's effect on the ecosystem are considered. Emissions to air, planned emissions to the sea and accident emissions and spills are treated, as well as other possible environmental effects. Consequences for fishery, cultural monuments and for the society in general are also examined (ml)

  8. RKU North Sea. Update on the regional consequence examination concerning the petroleum industry in the North Sea; RKU-Nordsjoeen. Oppdatering av regional konsekvensutredning for petroleumsvirksomhet i Nordsjoeen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-12-15

    An overview over prognoses for oil and gas production and the emissions related to these activities is provided for the years 2005-2025. A description of the Norwegian Continental Shelf's ecosystem, environmental technology employed, and considerations regarding the petroleum industry's effect on the ecosystem are considered. Emissions to air, planned emissions to the sea and accident emissions and spills are treated, as well as other possible environmental effects. Consequences for fishery, cultural monuments and for the society in general are also examined (ml)

  9. A database of archived drilling records of the drill cuttings piles at the North West Hutton oil platform

    International Nuclear Information System (INIS)

    Marsh, Roy

    2003-01-01

    Drill cuttings piles are found underneath several hundred oil platforms in the North Sea, and are contaminated with hydrocarbons and chemical products. This study characterised the environmental risk posed by the cuttings pile at the North West Hutton (NWH) oil platform. Data on the drilling fluids and chemical products used over the platform's drilling history were transferred from archived well reports into a custom database, to which were added toxicological and safety data. Although the database contained many gaps, it established that only seven chemical products used at NWH were not in the lowest category of the Offshore Chemicals Notification Scheme, and were used in only small quantities. The study therefore supports the view that the main environmental risk posed by cuttings piles comes from hydrocarbon contamination. The (dated) well records could help future core sampling to be targeted at specific locations in the cuttings piles. Data from many platforms could also be pooled to determine generic 'discharge profiles.' Future study would benefit from the existence, in the public domain, of a standardised, 'legacy' database of chemical products

  10. Temperature, salinity, oxygen and nutrients bottle and CTD data collected in the northern North Atlantic, Nordic and Arctic Seas from 1901 to 2011 (NODC Accession 0105532)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historical temperature, salinity, oxygen and nutrients bottle and CTD data collected in the Arctic Ocean, Barents Sea, Greenland Sea, Kara Sea, North Atlantic Ocean,...

  11. The oil spill modelling in the Sea of Japan: application to the tanker 'Nakhodka' 1997 incident

    International Nuclear Information System (INIS)

    Varlamov, S.M.; Yoon, J.-H.; Hirose, N.; Kawamura, H.

    1998-01-01

    In January 1997 the Russian tanker 'NAKHODKA' spilled into the Sea of Japan about 5000 tons of heavy fuel oil type C. Most of it reached the coast of Japan and damaged the environment. This incident forced the development of the operational system for the prediction of oil spills in the Sea of Japan. As a part of this system the model for oil spill modelling is presented. The modelled climatological sea currents were used in these simulators, generated by the three-dimensional primitive ocean circulation model with 10-minute horizontal resolution and 19 vertical levels. The model was forced by climatological atmospheric winds and heat fluxes. The wind currents in the upper sea layer were estimated by the wind data of ECMWF with 6 hours time and 0.5625-degree spatial resolution. The vertical structure of the total currents was interpolated using both wind driven currents and the climatological model currents data at the model levels. The oil spill was modelled with the particle tracking techniques. The model included the advection by currents, random diffusion, the buoyancy effect and the parameterisation of oil evaporation, biodegradation and beaching. For the deep sea the parameterisation of diffusion depends from the stratification, taken from the ocean circulation model output. The results demonstrated the defined relation with the observed propagation of the oil along the coast of Japan and highlighted the most important directions for the model development. The main is the realisation of the model for the real-time simulations and forecasts of the ocean currents with the fine resolution in the upper layer of the Sea of Japan. (author)

  12. 150 years of ecosystem evolution in the North Sea - from pristine conditions to acidification

    Science.gov (United States)

    Pätsch, Johannes; Lorkowski, Ina; Kühn, Wilfried; Moll, Andreas; Serna, Alexandra

    2010-05-01

    The 3-d coupled physical-biogeochemical model ECOHAM was applied to the Northwest European Shelf (47° 41‘ - 63° 53' N, 15° 5' W - 13° 55' E) for the years 1860, 1960 and continuously for the time interval 1970 - 2006. From stable nitrogen isotope analysis in sediment cores of the German Bight in the southeastern part of the North Sea (inner shelf) we found the period before 1860 unaffected by anthropogenic river inputs of nitrogen. After this period the delta15N-ratios significantly increased from ~6 per mil to more than 8 per mil in recent sediments indicating eutrophication by anthropogenic nitrate mainly from intensive agriculture fertilization. We deduced from the successful simulation of delta15N patterns in recent sediments that during pristine conditions nitrogen loads of the main continental rivers were about 10% of the modern input while the deposition of inorganic atmospheric nitrogen was 28% of the recent atmospheric flux. The 1960-sediment exhibited similar delta15N-values as the recent sediment which allows the conclusion that eutrophication in the German Bight predates the 1960 period of rapidly increasing river loads. By comparing model results with observational data in the North Sea we analyzed the variability of simulated carbon fluxes (1970-2006) constituting the so called "shelf pump" which transports atmospheric CO2 via biological fixation, vertical export and advection into the adjacent North Atlantic. Even though the highly variable North Atlantic water-inflow which correlated with the North Atlantic Oscillation Index (NAOI) supplied the northern North Sea with strongly varying nutrient inputs, the interannual variability of the strength of the shelf pump was mainly governed by the variability of the southern basin's biological productivity. The net ecosystem production (NEP) in the southern North Sea varies around zero inducing CO2 exchange with the atmosphere which is near equilibrium. In the northern North Sea the strong positive

  13. Distribution of Multipple Herbicide Resistant Eleusine Indica L. Gaertn. an Oil Palm Estate in North Sumatera

    OpenAIRE

    syahputra, ahmad bayu; Purba, Edison Purba; Hasanah, Yaya Hasanah

    2016-01-01

    Goosegrass (Eleusine indica) in a block of oil palm Estate at Serdang Bedagai, North Sumatera had been controlled using glyphosate and paraquat for more than 26 years continuously. Recently, it had been reported that the two herbicides failed to control the population. The estate consists of 4000 Ha or 437 blocks which had slightly different history in weed management. The objective of this study was to determine the distribution Eleusine indica Resistant to glyphosate and paraquat in the oil...

  14. Economics of Undiscovered Oil and Gas in the North Slope of Alaska: Economic Update and Synthesis

    Science.gov (United States)

    Attanasi, E.D.; Freeman, P.A.

    2009-01-01

    The U.S. Geological Survey (USGS) has published assessments by geologists of undiscovered conventional oil and gas accumulations in the North Slope of Alaska; these assessments contain a set of scientifically based estimates of undiscovered, technically recoverable quantities of oil and gas in discrete oil and gas accumulations that can be produced with conventional recovery technology. The assessments do not incorporate economic factors such as recovery costs and product prices. The assessors considered undiscovered conventional oil and gas resources in four areas of the North Slope: (1) the central North Slope, (2) the National Petroleum Reserve in Alaska (NPRA), (3) the 1002 Area of the Arctic National Wildlife Refuge (ANWR), and (4) the area west of the NPRA, called in this report the 'western North Slope'. These analyses were prepared at different times with various minimum assessed oil and gas accumulation sizes and with slightly different assumptions. Results of these past studies were recently supplemented with information by the assessment geologists that allowed adjustments for uniform minimum assessed accumulation sizes and a consistent set of assumptions. The effort permitted the statistical aggregation of the assessments of the four areas composing the study area. This economic analysis is based on undiscovered assessed accumulation distributions represented by the four-area aggregation and incorporates updates of costs and technological and fiscal assumptions used in the initial economic analysis that accompanied the geologic assessment of each study area.

  15. On the interpretation of SAR imagery from the Sea Empress oil spill

    International Nuclear Information System (INIS)

    Jones, B.; Mitchelson-Jacob, E.G.

    1998-01-01

    A method for monitoring oil spills using SAR imagery is suggested, based on the simulation of the wave spectrum using modelled surface winds. A first order separation of the purely wind-driven backscatter distribution and its modifications due to surfactant was made by parametrizing the effect of surfactant on the wave growth rate and on the reflective properties of the sea surface. The technique was applied to an SAR image showing the Sea Empress oil spill, in south-west Wales, UK. (author)

  16. The place of the Irish Sea oil and gas industryin the economy of the region

    International Nuclear Information System (INIS)

    Stoney, P.J.M.

    1995-01-01

    The economies of two areas close to the Irish Sea, Morecambe Bay and Liverpool Bay, are compared in order to illustrate the effect of the Irish Sea oil and gas industry on these regions. Capital investment projects connected with those industries during the construction and operational lifetime periods are considered in terms of direct, indirect and induced effects. Mathematical modelling is used to provide a conceptual basis for making inferences about the possible size of oil and gas industry effects on local economies. Information on employment in various regions and sectors of industry, including forecasts of future profitability are given. (UK)

  17. Innovative eco-friendly bio- solvent for combating sea surface and sedimented oil pollution

    Science.gov (United States)

    Theodorou, Paraskevas

    2017-04-01

    The combating of oil spill at sea surface by chemical dispersants accelerates the evaporation and disperse the oil into the water column, where it is broken down by natural processes and/or is sedimented at the sea bottom, especially at near coastal shallow areas, ports and marinas. The usual methodology for cleaning the sedimented oil from the sea bottom is mainly carried out via excavation and dumping of the polluted sediment into deeper sea areas, where the contamination is transferred from one area to another. The eco-friendly bio-solvent MSL Aqua 250 is an innovative new solution based mainly on natural constituents. The action mechanism and the effectiveness of this eco-friendly solvent is based on the high surface tension process. Organic compounds, including hydrocarbons upon coming in contact with MSL Aqua 250 solvent generate a significant surface tension reaction, which is able to alter the organic compounds to liquid form and then to drastically evaporate it. The use of MSL Aqua 250 solvent, both at sea surface and at the bottom, has the following advantages compared to the dispersants: • Efficient solution without transferring the pollution from sea surface to the water column and to the bottom or disturbing the Aquatic Eco System. • Non-Toxic. • Environmentally friendly with a restoration of marine life in the Eco System. • Cost effective. The MSL Aqua 250 solvent has been tested in cooperation with the Cyprus Department of Fisheries and Marine Research and the Technological University of Cyprus and used during the years 2015 and 2016 in marinas and fishing shelters in Cyprus faced oil pollution, with high concentration in the sea water and at the sea bottom of chemical parameters (BOD5, COD, FOG, TKN, TP, TPH), with excellent results.

  18. Detection of DNA damage in mussels and sea urchins exposed to crude oil using comet assay

    International Nuclear Information System (INIS)

    Taban, I.C.; Bechmann, R.K.; Torgrimsen, S.; Baussant, T.; Sanni, S.

    2004-01-01

    The single-cell microgel electrophoresis assay or the comet assay was used to evaluate DNA damage of dispersed crude oil on sea urchins (Strongylocentrotus droebachiensis) and mussels (Mytilus edulis L.). Sea urchins were exposed to 0.06 and 0.25 mg/L dispersed crude oil in a continuous flow system, while the mussels were exposed to 0.015, 0.06 and 0.25 mg/L dispersed crude oil. Sea urchin coelomocytes and mussel haemocytes were sampled after 4 and 5 weeks exposure, respectively. In the sea urchin coelomocytes, there was a significant concentration-related increase in the percentage of DNA in comet tail. In mussel haemocytes, there was a significantly higher percentage of DNA in comet tail for all treatments compared to the control. The responses were concentration-related up to 0.06 mg/L oil. The two highest exposure concentrations of mussels were not significantly different from each other. These results indicate that the comet assay can be used for biomonitoring of DNA damage in marine invertebrates following oil contamination. (author)

  19. Sensitivity of Calanus spp. copepods to environmental changes in the North Sea using life-stage structured models

    DEFF Research Database (Denmark)

    Maar, Marie; Møller, Eva Friis; Gürkan, Zeren

    2013-01-01

    Sea because it allows them to utilize the spring bloom more efficiently and independently of the timing and amount of oceanic inflow. The combination of lower temperatures, higher overwintering and oceanic inflow simulating the situation in the 1960s largely favoured C. finmarchicus and their relative......, overwintering and oceanic inflow in the North Sea. Life-stage structured models are validated against CPR data and vertical distributions north of the Dogger Bank in the North Sea for the reference year 2005. The model shows that 1) ± 2°C changes from the current level mainly influence the seasonal patterns...... and not the relative occurrence of the two species, 2) changes due to oceanic inflow mainly appeared in the northern and southern part of the North Sea connected to the NE Atlantic and not in the central part and 3) the abundance of Calanus species were very sensitive to the degree of overwintering within the North...

  20. In situ burning via towed boom of oil spilled at sea

    International Nuclear Information System (INIS)

    Carrier, G.; Fendell, F.; Mitchell, J.

    1992-01-01

    In this paper, operational guidance for the efficient use of combustion in the cleanup of a surface oil film, formed as a result of a spill at sea, is sought by approximate analysis. In remediation by burning, the spilled oil itself provides the energy for its cleanup. Attention is focused on situations holding relatively far from the source of the spill and/or relatively long after the spill: the oil is taken to have so dispersed that the thickness of the film is on the order of a few millimeters. Under such conditions, the oil film is unlikely to burn without the use of multiple towed booms, each boom spreading its already-ignited, localized fire to continuously collected, previously unignited portions of the oil film. A simple, quasisteady, two-dimensional analysis suggests efficient values for the tow speed and the tow--line length as functions of such parameters as the oil density, oil-film thickness, oil burn/evaporation rate, etc. The analysis leads to specific suggestions for apparently unreported laboratory experiments that may be informative prior to at-sea operation

  1. Land-sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

    Science.gov (United States)

    Donders, Timme H.; van Helmond, Niels A. G. M.; Verreussel, Roel; Munsterman, Dirk; ten Veen, Johan; Speijer, Robert P.; Weijers, Johan W. H.; Sangiorgi, Francesca; Peterse, Francien; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.; Lourens, Lucas; Kuhlmann, Gesa; Brinkhuis, Henk

    2018-03-01

    We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (˜ 2.6-1.8 Ma) multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of Northern Hemisphere glaciation (NHG) in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to early Pleistocene glacial-interglacial cycles and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS) 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high-resolution reconstructions of relative terrestrial and sea surface temperature (TT and SST), vegetation, relative sea level, and coastal influence.During the prominent cold stages MIS 98 and 96, as well as 94, the record indicates increased non-arboreal vegetation, low SST and TT, and low relative sea level. During the warm stages MIS 99, 97, and 95 we infer increased stratification of the water column together with a higher percentage of arboreal vegetation, high SST, and relative sea level maxima. The early Pleistocene distinct warm-cold alterations are

  2. Land–sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

    Directory of Open Access Journals (Sweden)

    T. H. Donders

    2018-03-01

    Full Text Available We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (∼ 2.6–1.8 Ma multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of Northern Hemisphere glaciation (NHG in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to early Pleistocene glacial–interglacial cycles and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high-resolution reconstructions of relative terrestrial and sea surface temperature (TT and SST, vegetation, relative sea level, and coastal influence.During the prominent cold stages MIS 98 and 96, as well as 94, the record indicates increased non-arboreal vegetation, low SST and TT, and low relative sea level. During the warm stages MIS 99, 97, and 95 we infer increased stratification of the water column together with a higher percentage of arboreal vegetation, high SST, and relative sea level maxima. The early Pleistocene distinct

  3. 76 FR 30956 - Outer Continental Shelf, Alaska OCS Region, Chukchi Sea Planning Area, Oil and Gas Lease Sale 193

    Science.gov (United States)

    2011-05-27

    ... Point Hope et al., v. Salazar, No. 1:08-cv-00004-RRB (D. Alaska)]. The sale was conducted in February... Continental Shelf, Alaska OCS Region, Chukchi Sea Planning Area, Oil and Gas Lease Sale 193 AGENCY: Bureau of...: BOEMRE announces the availability of a Revised Draft SEIS, OCS Oil and Gas Lease Sale 193, Chukchi Sea...

  4. Review of methods of detection of oil pollution in the sea

    Energy Technology Data Exchange (ETDEWEB)

    Gurgul, H; Pawlak, B

    1981-01-01

    In connection with the necessary of detection, recognition, and identification of oil spills in the sea, existing and prospective contactless methods of detecting oil on the water surface are reviewed, including such methods as optical (in IR, visible, and UV, including lasers, bands), radar with the use of fluorescence and interference phenomena; aerial and space photography and shooting. Parameters of instruments that use the optical and radar methods, including CO/sub 2/-, nitrogen and helium-cadmium lasers, are presented.

  5. Climate drift of AMOC, North Atlantic salinity and arctic sea ice in CFSv2 decadal predictions

    Science.gov (United States)

    Huang, Bohua; Zhu, Jieshun; Marx, Lawrence; Wu, Xingren; Kumar, Arun; Hu, Zeng-Zhen; Balmaseda, Magdalena A.; Zhang, Shaoqing; Lu, Jian; Schneider, Edwin K.; Kinter, James L., III

    2015-01-01

    There are potential advantages to extending operational seasonal forecast models to predict decadal variability but major efforts are required to assess the model fidelity for this task. In this study, we examine the North Atlantic climate simulated by the NCEP Climate Forecast System, version 2 (CFSv2), using a set of ensemble decadal hindcasts and several 30-year simulations initialized from realistic ocean-atmosphere states. It is found that a substantial climate drift occurs in the first few years of the CFSv2 hindcasts, which represents a major systematic bias and may seriously affect the model's fidelity for decadal prediction. In particular, it is noted that a major reduction of the upper ocean salinity in the northern North Atlantic weakens the Atlantic meridional overturning circulation (AMOC) significantly. This freshening is likely caused by the excessive freshwater transport from the Arctic Ocean and weakened subtropical water transport by the North Atlantic Current. A potential source of the excessive freshwater is the quick melting of sea ice, which also causes unrealistically thin ice cover in the Arctic Ocean. Our sensitivity experiments with adjusted sea ice albedo parameters produce a sustainable ice cover with realistic thickness distribution. It also leads to a moderate increase of the AMOC strength. This study suggests that a realistic freshwater balance, including a proper sea ice feedback, is crucial for simulating the North Atlantic climate and its variability.

  6. Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

    NARCIS (Netherlands)

    van Aken, H.M.; de Jong, M.F.; Yashayaev, I.

    2011-01-01

    Time series of profiles of potential temperature, salinity, dissolved oxygen, and planetary potential vorticity at intermediate depths in the Labrador Sea, the Irminger Sea, and the Iceland Basin have been constructed by combining the hydrographic sections crossing the sub-arctic gyre of the North

  7. Spatio-temporal variability of the North Sea cod recruitment in relation to temperature and zooplankton.

    Directory of Open Access Journals (Sweden)

    Delphine Nicolas

    Full Text Available The North Sea cod (Gadus morhua, L. stock has continuously declined over the past four decades linked with overfishing and climate change. Changes in stock structure due to overfishing have made the stock largely dependent on its recruitment success, which greatly relies on environmental conditions. Here we focus on the spatio-temporal variability of cod recruitment in an effort to detect changes during the critical early life stages. Using International Bottom Trawl Survey (IBTS data from 1974 to 2011, a major spatio-temporal change in the distribution of cod recruits was identified in the late 1990s, characterized by a pronounced decrease in the central and southeastern North Sea stock. Other minor spatial changes were also recorded in the mid-1980s and early 1990s. We tested whether the observed changes in recruits distribution could be related with direct (i.e. temperature and/or indirect (i.e. changes in the quantity and quality of zooplankton prey effects of climate variability. The analyses were based on spatially-resolved time series, i.e. sea surface temperature (SST from the Hadley Center and zooplankton records from the Continuous Plankton Recorder Survey. We showed that spring SST increase was the main driver for the most recent decrease in cod recruitment. The late 1990s were also characterized by relatively low total zooplankton biomass, particularly of energy-rich zooplankton such as the copepod Calanus finmarchicus, which have further contributed to the decline of North Sea cod recruitment. Long-term spatially-resolved observations were used to produce regional distribution models that could further be used to predict the abundance of North Sea cod recruits based on temperature and zooplankton food availability.

  8. Prevalence and molecular characterisation of Acanthocephala in pinnipedia of the North and Baltic Seas

    Directory of Open Access Journals (Sweden)

    Patrick Waindok

    2018-04-01

    Full Text Available Harbour seals (Phoca vitulina and grey seals (Halichoerus grypus are final hosts of acanthocephalans in the German North and Baltic Seas. Parasitic infections in seals can cause pathological changes, which may result in deteriorated health of the host. Common gastrointestinal parasites of harbour and grey seals are acanthocephalans and a number of 275 of 2460 (11.2% investigated seals from 1996 to 2013 were infected with Corynosoma spp. (Acanthocephala, Polymorphidae. The prevalence showed a wave-like pattern: it increased from 1.2% and 0.4% in 1996 and 1997, respectively, to 23.9% during the second phocine distemper epizootic in 2002 and decreased to 6.2% in 2004. In 2005, prevalence peaked again with 25.0% followed by a decrease to 9.3% in 2009 and an increase to 38.5% in 2012. Statistical analysis revealed that harbour seals originating from the North Sea showed a higher prevalence than grey seals, whereas no significant difference between grey and harbour seals from the Baltic Sea was observed. Furthermore, juvenile pinnipedia from the North Sea were significantly less infected with Corynosoma spp. than seals older than seven month. Molecular species identification as well as phylogenetic relationship analysis among the detected Corynosoma species were achieved by sequencing and comparisons of the ribosomal ITS1-5.8S-ITS2-complex and cytochrome-c-oxidase I gene. Molecular analysis resulted in a newly arranged distribution of Acanthocephala in the North Sea as in contrast to previous studies, C. strumosum could not be confirmed as predominant species. Instead, C. magdaleni and a C. magdaleni isolate (isolate Pv1NS with an atypical number of longitudinal rows of hooks at the proboscis were detected. Furthermore, morphological and molecular analyses indicate the possible finding of a cryptic species (Candidatus Corynosoma nortmeri sp. nov.. Keywords: Acanthocephala, Acantocephalans, Corynosoma, Seals, ITS, Cytochrome-c-oxidase, Marine parasites

  9. Hierarchical modeling of bycatch rates of sea turtles in the western North Atlantic

    Science.gov (United States)

    Gardner, B.; Sullivan, P.J.; Epperly, S.; Morreale, S.J.

    2008-01-01

    Previous studies indicate that the locations of the endangered loggerhead Caretta caretta and critically endangered leatherback Dermochelys coriacea sea turtles are influenced by water temperatures, and that incidental catch rates in the pelagic longline fishery vary by region. We present a Bayesian hierarchical model to examine the effects of environmental variables, including water temperature, on the number of sea turtles captured in the US pelagic longline fishery in the western North Atlantic. The modeling structure is highly flexible, utilizes a Bayesian model selection technique, and is fully implemented in the software program WinBUGS. The number of sea turtles captured is modeled as a zero-inflated Poisson distribution and the model incorporates fixed effects to examine region-specific differences in the parameter estimates. Results indicate that water temperature, region, bottom depth, and target species are all significant predictors of the number of loggerhead sea turtles captured. For leatherback sea turtles, the model with only target species had the most posterior model weight, though a re-parameterization of the model indicates that temperature influences the zero-inflation parameter. The relationship between the number of sea turtles captured and the variables of interest all varied by region. This suggests that management decisions aimed at reducing sea turtle bycatch may be more effective if they are spatially explicit. ?? Inter-Research 2008.

  10. Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)

    International Nuclear Information System (INIS)

    Pham, M.K.; Sanchez-Cabeza, J.A.; Povinec, P.P.; Arnold, D.; Benmansour, M.; Bojanowski, R.; Carvalho, F.P.; Kim, C.K.; Esposito, M.; Gastaud, J.; Gasco, C.L.; Ham, G.J.; Hegde, A.G.; Holm, E.; Jaskierowicz, D.; Kanisch, G.; Llaurado, M.; La Rosa, J.; Lee, S.-H.; Liong Wee Kwong, L.; Le Petit, G.; Maruo, Y.; Nielsen, S.P.; Oh, J.-S.; Oregioni, B.; Palomares, J.; Pettersson, H.B.L.; Rulik, P.; Ryan, T.P.; Sato, K.; Schikowski, J.; Skwarzec, B.; Smedley, P.A.; Tarjan, S.; Vajda, N.; Wyse, E.

    2006-01-01

    A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides ( 4 K, 137 Cs, 232 Th, 234 U, 235 U, 238 U, 238 Pu, 239+24 Pu and 241 Am) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides ( 9 Sr, 21 Pb( 21 Po), 226 Ra, 239 Pu, 24 Pu 241 Pu). Less frequently reported radionuclides ( 99 Tc, 129 I, 228 Th, 23 Th and 237 Np) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units

  11. Post-Glacial Development of Western North Atlantic - Labrador Sea Oceanographic Circulation

    DEFF Research Database (Denmark)

    Sheldon, Christina

    2015-01-01

    The subpolar North Atlantic Ocean – Labrador Sea region is an important site for both oceanographic and atmospheric circulation. The convergence of ocean currents causes downwelling of cold, saline water in the subpolar gyre, helping to drive the world-wide thermohaline circulation system. The main......, the subpolar gyre weakened, which carried less Gulf Stream-derived water to the western North Atlantic Ocean via the West Greenland Current and the Slopewater Current, south of Newfoundland. Changes in the subpolar gyre circulation had developed to be analogous to the modern climate by approximately 2 cal kyr...... surface currents involved in the gyre are the south-flowing, cold and relatively fresh Labrador Current and the north-flowing, warm and relatively saline Gulf Stream. The oceanic front between these two major currents moves north and south, dependent on the relative strengths of the currents, impacting...

  12. Vertical nutrient fluxes, turbulence and the distribution of chlorophyll a in the north-eastern North Sea

    Science.gov (United States)

    Bendtsen, Jørgen; Richardson, Katherine

    2017-04-01

    During summer the northern North Sea is characterized by nutrient rich bottom water masses and nutrient poor surface layers. This explains the distribution of chlorophyll a in the water column where a subsurface maximum, referred to as the deep chlorophyll maximum (DCM), often is present during the growth season. Vertical transport of nutrients between bottom water masses and the well lit surface layer stimulates phytoplankton growth and this generally explains the location of the DCM. However, a more specific understanding of the interplay between vertical transports, nutrient fluxes and phytoplankton abundance is required for identifying the nature of the vertical transport processes, e.g the role of advection versus vertical turbulent diffusion or the role of localized mixing associated with mesoscale eddies. We present results from the VERMIX study in the north-eastern North Sea where nutrients, chlorophyll a and turbulence profiles were measured along five north-south directed transects in July 2016. A high-resolution sampling program, with horizontal distances of 1-10 km between CTD-stations, resolved the horizontal gradients of chlorophyll a across the steep bottom slope from the relatively shallow central North Sea ( 50-80 m) towards the deep Norwegian Trench (>700 m). Low oxygen concentrations in the bottom water masses above the slope indicated enhanced biological production where vertical mixing would stimulate phytoplankton growth around the DCM. Measurements of variable fluorescence (Fv/Fm) showed elevated values in the DCM which demonstrates a higher potential for electron transport in the Photosystem II in the phytoplankton cells, i.e. an indication of nutrient-rich conditions favorable for phytoplankton production. Profiles of the vertical shear and microstructure of temperature and salinity were measured by a VMP-250 turbulence profiler and the vertical diffusion of nutrients was calculated from the estimated vertical turbulent diffusivity and the

  13. Histopathologic lesions associated with crude oil exposure in sea otters. Marine mammal study 6-10. Exxon Valdez oil spill state/federal natural resources damage assessment final report

    Energy Technology Data Exchange (ETDEWEB)

    Lipscomb, T.P.; Harris, R.K.; Moeller, R.B.; Pletcher, J.M.; Haebler, R.J.

    1996-06-01

    Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters (Enhydra lutris) that appeared oiled, were in danger of becoming oiled, or were behaving abnormally were captured and taken to rehabilitation centers. Oil exposure was assessed by visual examination on arrival at the centers. Tissues from 51 oiled sea otters and from 6 unoiled sea otters that died in rehabilitation centers were examined histologically. Histologic examinations were performed on tissues from 5 sea otters found dead with external oil present shortly after the spill. Necropsies were performed on 214 sea otters that had been collected and frozen in the period following the oil spill. Tissues from 6 apparently normal sea otters collected from an area not affected by the oil spill were examined histologically, and none of these lesions were found. We conclude that pulmonary interstitial emphysema, gastric erosion and hemorrhage, centrilobular hepatic necrosis, and hepatic and renal lipidosis were associated with exposure to crude oil in sea otters.

  14. Oil and natural gas prospects: Middle East and North Africa

    International Nuclear Information System (INIS)

    Khatib, Hisham

    2014-01-01

    The MENA region is endowed with enormous resources of oil and gas, rendering it the world′s richest region in this regard. Endowment differs from one country to another with few countries are almost dry; however the economic benefits proliferated to almost every country in the region. In spite of some doubts being cast about the amount of proven oil reserves, these with improved technology and new discoveries are increasing year after another. With no long term feasible alternatives to oil for transport and the increasing trade in LNG, the region′s importance as a world′s leading supplier of fossil fuels will continue for decades to come. However, these favourable prospects hide many challenges facing the MENA region, among them is the difficulty in mobilizing investment funds for sustaining and increasing output to feed growing global demand. Growing local demand, due to the proliferation of subsides, is another worrying aspect that already caused few countries with modest resources to become oil importers instead of exporters, with larger exporters decreasing their surplus output. The region is also still mainly dependant on foreign technologies and skilled manpower. Regional cooperation in oil and gas networks and electricity interconnections is still modest. The region has a long history of conflict; correspondingly it is a major importer of armaments which is increasingly eating a lot of its surplus income. With the political and social changes presently taking place in many MENA countries, due to the Arab spring and continuation of local conflicts, the sustainability of supplies from the region are increasingly a source of worry to MENA exporters and its many importers. It is also causing increasing involvement of the super powers in regional affairs. - Highlights: • Global oil and gas reserves and prices. • Energy sustainability and the Middle East. • Energy economics and investments in the Middle East

  15. Variability and connectivity of plaice populations from the Eastern North Sea to the Western Baltic Sea, and implications for assessment and management

    DEFF Research Database (Denmark)

    Ulrich, Clara; Boje, Jesper; Cardinale, Massimiliano

    2013-01-01

    and management. Plaice in Kattegat and Skagerrak have traditionally been considered as one stock unit. Current understanding indicates that several plaice components may exist in the transition area between the North Sea and the Baltic Sea. A comprehensive review of all available biological knowledge on plaice...

  16. Strategic environmental assessment for sustainable expansion of palm oil biofuels in Brazilian north region

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Carolina

    2010-09-15

    Biofuels development in Brazil is a key factor for the environment and sustainable development of the country. Brazil has great potential of available areas and has favourable climate and geography for biofuel production, such as palm oil, soy, sugar cane, etc. This research aims to evaluate palm oil production and expansion in Para state, in the north of Brazil and also Amazonian territory. Degraded land will be evaluated through remote sensing, because palm oil crops should be placed in these lands, and secondly, expansion scenarios would be created. This PhD research will be a decision support tool for public policies.

  17. Co-movements of Alaska North Slope and UK Brent crude oil prices

    International Nuclear Information System (INIS)

    Ewing, B.T.; Harter, C.L.

    2000-01-01

    In order to study the inter-relationships of international crude oil markets, empirical analyses are used to investigate univariate and multivariate relationships between Alaska North Slope and UK Brent oil prices. Using monthly data from the period 1974-1996, the results show that both price series follow a random walk and that these oil markets share a long-run common trend. The empirical results suggest that the two markets are 'unified'. That is, they are competitive, and there is price convergence in the markets. (author)

  18. The Use of the Lead and Line by Early Navigators in the North Sea?

    Directory of Open Access Journals (Sweden)

    John Kemp

    2014-12-01

    Full Text Available This paper draws attention to the lack of information as to how early North Sea sailors navigated, particularly during the one thousand year period that followed Roman times. The lead and line was the only navigational aid available for most of this period, but there is little recorded as to whether it was used simply for ensuring a ship or boat had enough water to proceed or whether, together with the knowledge it provided of the nature of the sea bed, it was used as a more positive position fixing device. The author would appreciate any information relating to navigation techniques used during this period.

  19. Derived concentration factors for caesium-137 in edible species of North Sea fish

    International Nuclear Information System (INIS)

    Steele, A.K.

    1990-01-01

    Concentration factor (CF=Bq kg -1 fillet/Bg kg -1 filtered sea water) values for 137 Cs in fillets of cod (Gadus morhua), haddock (Merlanogrammus aeglefinus), plaice (Pleuronectes platessa) and whiting (Merlangius merlangius), were derived from fish and filtered seawater concentrations. Samples were collected in twelve sampling boxes in the North Sea over an eight-year period - 1978-1985. The range of results with species, between species, and between surveys are discussed. Mean CF values of 92, 58, 39 and 150 were found in cod, haddock, plaice and whiting respectively. These support the International Atomic Energy Authority recommended CF value of 100 for fish in generalised dose assessments. (author)

  20. PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill

    Science.gov (United States)

    Ricca, Mark A.; Miles, A. Keith; Ballachey, Brenda E.; Bodkin, James L.; Esler, Daniel N.; Trust, Kimberly A.

    2010-01-01

    Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill.

  1. Prevention of oil spill pollution in sea water using locally available materials

    International Nuclear Information System (INIS)

    Anisuddin, S.; Al-Hashar, Naseer A.; Tahseen, S.

    2005-01-01

    Oil spill pollution, a severe environmental problem, which persists in marine environment or in inland water across the world, has grown to an alarming magnitude with increased levels of oil production and transport. The causes oil pollution are categorized as either accidental or operational, wherever oil is produced, transported, stored and used on the surface of sea or land. Hence, it is almost impossible for marine life to be freed from the adverse affects of oil spill, through the discharge of oil is controlled by an international convention. Prime concern for the health of marine life has created an instinct for undertaking this study by authors. Objectives of the present work include testing of four different local materials in separating oil from having different oil concentrations, and their efficiency of removal. The work also focuses on effect of time of contact and dosage of materials used for oil removal. Corchorus depressus locally available has proved to be more effective when compared to other materials utilized in addressing oil-spill related problems. At the same time its byproducts do not give rise to unwanted hazards to marine life. (author)

  2. Potential impacts of offshore oil spills on polar bears in the Chukchi Sea.

    Science.gov (United States)

    Wilson, Ryan R; Perham, Craig; French-McCay, Deborah P; Balouskus, Richard

    2018-04-01

    Sea ice decline is anticipated to increase human access to the Arctic Ocean allowing for offshore oil and gas development in once inaccessible areas. Given the potential negative consequences of an oil spill on marine wildlife populations in the Arctic, it is important to understand the magnitude of impact a large spill could have on wildlife to inform response planning efforts. In this study we simulated oil spills that released 25,000 barrels of oil for 30 days in autumn originating from two sites in the Chukchi Sea (one in Russia and one in the U.S.) and tracked the distribution of oil for 76 days. We then determined the potential impact such a spill might have on polar bears (Ursus maritimus) and their habitat by overlapping spills with maps of polar bear habitat and movement trajectories. Only a small proportion (1-10%) of high-value polar bear sea ice habitat was directly affected by oil sufficient to impact bears. However, 27-38% of polar bears in the region were potentially exposed to oil. Oil consistently had the highest probability of reaching Wrangel and Herald islands, important areas of denning and summer terrestrial habitat. Oil did not reach polar bears until approximately 3 weeks after the spills. Our study found the potential for significant impacts to polar bears under a worst case discharge scenario, but suggests that there is a window of time where effective containment efforts could minimize exposure to bears. Our study provides a framework for wildlife managers and planners to assess the level of response that would be required to treat exposed wildlife and where spill response equipment might be best stationed. While the size of spill we simulated has a low probability of occurring, it provides an upper limit for planners to consider when crafting response plans. Published by Elsevier Ltd.

  3. The Aegean Sea incident: A quantitative evaluation of the fate of the oil

    International Nuclear Information System (INIS)

    Bergueiro Lopez, J.R.; Morales Correas, N.; Dominguez Laseca, F.

    1993-01-01

    In December 1992, the tanker Aegean Sea was shipwrecked at the entrance to a harbor in northwest Spain. The accident was partly due to bad weather conditions and possibly also to the poor condition of the ship, which subsequently broke in two and caught fire. The tanker was carrying 79,000 tons of low-viscosity light oil, of which 40-60% burned. The oil slick coming from the wrecked ship spread westward and northward into nearby bays, impacting 100-200 km of coast with varying degrees of severity. Strong winds and stormy sea conditions at the time of the incident favored evaporation and natural dispersion of much of the spilled oil. Spill response and countermeasures included restriction of fishing zones, manual and mechanical cleaning of beaches and nearby rocks, use of pumps and skimmers to recover oil from water and shore, and stirring oil-penetrated sand to ca 50 cm depth to facilitate oxygenation and ensure degradation of oil traces. About 6,000 m 3 of emulsified oil were collected from the water and another 1,000 m 3 from the shore; 5,000-6,000 tons of unspilled oil was recovered from the tanker. A simulation model estimated that if no burning had occurred, 2/3 of the oil would have dispersed in the sea or evaporated into the air in ca 3 d. Ecological impacts on plankton, benthos, and pelagic and bird communities appears to have been minor or at least relatively localized. Long-term ecological impacts are being studied. However, zones of fish/shellfish breeding were affected, with short-term damages estimated at over $45 million. 9 refs., 5 figs., 1 tab

  4. Atmospheric fate of oil matter adsorbed on sea salt particles under UV light

    Science.gov (United States)

    Vaitilingom, M.; Avij, P.; Huang, H.; Valsaraj, K. T.

    2014-12-01

    The presence of liquid petroleum hydrocarbons at the sea water surface is an important source of marine pollution. An oil spill in sea-water will most likely occur due to an involuntary accident from tankers, offshore platforms, etc. However, a large amount of oil is also deliberately spilled in sea-water during the clean-out process of tank vessels (e.g. for the Mediterranean Sea, 490,000 tons/yr). Moreover, the pollution caused by an oil spill does not only affect the aquatic environment but also is of concern for the atmospheric environment. A portion of the oil matter present at the sea-water surface is transported into the atmosphere viaevaporation and adsorption at the surface of sea spray particles. Few studies are related to the presence of oil matter in airborne particles resulting from their adsorption on sea salt aerosols. We observed that the non-volatile oil matter was adsorbed at the surface of sea-salt crystals (av. size of 1.1 μm). Due to their small size, these particles can have a significant residence time in the atmosphere. The hydrocarbon matter adsorbed at the surface of these particles can also be transformed by catalyzers present in the atmosphere (i.e. UV, OH, O3, ...). In this work, we focused on the photo-oxidation rates of the C16 to C30alkanes present in these particles. We utilized a bubble column reactor, which produced an abundance of small sized bubbles. These bubbles generated droplets upon bursting at the air-salt water interface. These droplets were then further dried up and lifted to the top of the column where they were collected as particles. These particles were incubated in a controlled reactor in either dark conditions or under UV-visible light. The difference of alkane content analyzed by GC-MS between the particles exposed to UV or the particles not exposed to UV indicated that up to 20% in mass was lost after 20 min of light exposure. The degradation kinetics varied for each range of alkanes (C16-20, C21-25, C26

  5. Radiative evaporation of oil spills on seas or rivers

    International Nuclear Information System (INIS)

    Summerfield, M.

    1993-01-01

    Because of the self-evident drawbacks of in situ oil burning as a means of removing spilled oil from water surfaces, a similar technique suggests itself: evaporation of the oil by absorbed heat. Of the various ways in which heat may be brought to the oil surface, intense radiation seems to be the most convenient technique. Oil spilled on water surfaces can be collected by a boom floating in the water, gathered in a catenary-like contour, and deep enough to absorb the beam of radiation near the apex of the catenary. It seems likely that the circulation of oil in the gathered oil layer would serve to assure the minimum of heat conduction (loss of heat) to the water below. The question is, does a radiator intense enough to evaporate oil at a fast enough rate exist? The answer seems to be that a system does indeed exist, developed by the Gas Research Institute, Chicago, Illinois, and manufactured under GRI sponsorship by at least two companies. It was developed for such applications as paint drying. The radiator is heated to over 1400 K by natural gas combustion (with air); the hot surface is made of a ceramic. The efficiency of the overall process, from the standard heat of combustion to the radiation beam emitted, is about 40 percent. If one assumes a reasonable efficiency for the absorption of radiation and its conversion to heat and then its conversion to evaporated oil, one can compute the beam size, the radiator dimensions, the duration required for a boom-full of oil (only one) and the cost. It turns out that, for a 1,000 gal spill (more than the daily average), a duration of about 5 hours suffices for a single overhead radiator; the cost would be about $400 in fuel. A boat carrying the fuel tanks to feed the radiator, trailing the boom apex, is probably the best way to direct the radiation to the oil surface. Cleanup of a spill in this way is assured. One drawback is the smell of the atmosphere laden with the vapor

  6. Microbial water diversion technique-designed for near well treatment in low temperature sandstone reservoirs in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Paulsen, J.E.; Vatland, A. [RF-Rogaland Research, Stavanger (Norway); Sorheim, R. [SINTEF, Oslo (Norway)] [and others

    1995-12-31

    A Norwegian Research Program on Improved Oil Recovery (IOR) in North Sea reservoirs was launched in 1992. Microbial methods, applied in this context, is a part of this program. The scope, the methodological approach, and results from the three first years are presented. Water profile control, using biomass to block high permeable zones of a reservoir, has been investigated using nitrate-reducing bacteria in the injected sea water as plugging agents. Emphasis has been put on developing a process that does not have disadvantages secondary to the process itself, such as souring and impairment of the overall injectivity of the field. Data from continuous culture studies indicate that souring may successfully be mitigated by adding nitrite to the injected seawater. The morphology and size of generic-nitrate-reducing seawater bacteria have been investigated. Screening of growth-promoting nutrients has been carried out, and some sources were detected as favorable. Transport and penetration of bacteria in porous media have been given special attention. Investigations with sand packs, core models, and pore micromodels have been carried out. The inherent problems connected with permeability contrasts and flow patterns, versus bacterial behavior, are believed to be critical for the success of this technology. Data from the transport and blocking experiments with the porous matrices confirm this concern. The technology is primarily being developed for temperatures less than 40{degrees}C.

  7. Origins of wind-driven intraseasonal sea level variations in the North Indian Ocean coastal waveguide

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, I.; Vialard, J.; Lengaigne, M.; Han, W.; Mc; Durand, F.; Muraleedharan, P.M.

    version: Geophys. Res. Lett., vol.40(21); 2013; 5740-5744 Origins of wind-driven intraseasonal sea level variations in the North Indian Ocean coastal waveguide I. Suresh1, J. Vialard2, M. Lengaigne2, W. Han3, J. McCreary4, F. Durand5, P.M. Muraleedharan1... reversing winds. These wind variations drive seasonal equatorial Kelvin and Rossby wave responses. The seasonal equatorial Kelvin waves propagate into the North Indian Ocean (hereafter NIO) as coastal Kelvin waves [McCreary et al., 1993]. As a result...

  8. Dimorphic transition in Yarrowia lipolytica isolated from oil-polluted sea water

    International Nuclear Information System (INIS)

    Zinjarde, Smita S.; Pant, Aditi; Deshpande, Mukund V.

    1998-01-01

    Fungal cultures from oil-polluted sea water near Mumbai, India have been studies for their capability to degrade crude oil. A yeast isolate identified as Yarrowia lipolytica was further investigated with respect to its dimorphic behaviour and alkane degradation. Y. lipolytica NCIM 3589 in the yeast form degraded the aliphatic fraction of crude oil and also pure alkanes (20-60% within 48h) under aerobic conditions. Unlike most Y. lipolytica strains, our isolate required partial anaerobiosis for mycelium formation. Studies with two isolates suggested that mycelium to yeast transition may be the prerequisite for effective alkane degradation. (author)

  9. Sea-ice evaluation of NEMO-Nordic 1.0: a NEMO-LIM3.6-based ocean-sea-ice model setup for the North Sea and Baltic Sea

    Science.gov (United States)

    Pemberton, Per; Löptien, Ulrike; Hordoir, Robinson; Höglund, Anders; Schimanke, Semjon; Axell, Lars; Haapala, Jari

    2017-08-01

    The Baltic Sea is a seasonally ice-covered marginal sea in northern Europe with intense wintertime ship traffic and a sensitive ecosystem. Understanding and modeling the evolution of the sea-ice pack is important for climate effect studies and forecasting purposes. Here we present and evaluate the sea-ice component of a new NEMO-LIM3.6-based ocean-sea-ice setup for the North Sea and Baltic Sea region (NEMO-Nordic). The setup includes a new depth-based fast-ice parametrization for the Baltic Sea. The evaluation focuses on long-term statistics, from a 45-year long hindcast, although short-term daily performance is also briefly evaluated. We show that NEMO-Nordic is well suited for simulating the mean sea-ice extent, concentration, and thickness as compared to the best available observational data set. The variability of the annual maximum Baltic Sea ice extent is well in line with the observations, but the 1961-2006 trend is underestimated. Capturing the correct ice thickness distribution is more challenging. Based on the simulated ice thickness distribution we estimate the undeformed and deformed ice thickness and concentration in the Baltic Sea, which compares reasonably well with observations.

  10. Middle east and North African oil in international relations (from 1970 to these days)

    International Nuclear Information System (INIS)

    Rafie, Hossein

    1999-01-01

    Petroleum is not purely an economical product, its main role in world economy and its concentration in Middle East and North Africa (two third of world reserves) made influence international politics. Knowing the nature of the region, petroleum and politics make one. The politicization of oil in the region starts, first of all, with the efforts of some powers, through their companies, to dominate oil countries, which by reaction incite these countries to eliminate foreign domination and establish their national control on oil matters. The situation is changing progressively. The position of productive states got stronger with the beginning of the 1970's which permitted the use of oil, in a way relatively efficient, as an instrument of power. Consequently, the balance of power shifted deeply in the favor of producers. On this basis, the argument consists of three parts: the first puts theoretic bases - theory of economical arm - and defines geographical and historical environment of the research. The second part studies the period of force of the oil countries, from the fourth Israel-Arab war and oil embargo that followed it, to the end of the second oil slump. The third part explains the shift of power on the international scene and the relative decline of oil power for the states of the region. The analysis of impact of the oil slump in 1986 and the mini impact of the second Persian Gulf war, quickly dominated, lead to clear the actual situation and outline the viewpoint of the future. (author)

  11. Sea@shore: informational governance in marine spatial conflicts at the North Sea

    NARCIS (Netherlands)

    Toonen, H.M.

    2013-01-01

    Oceans and seas seem to be an empty space and untouched wilderness, but are in fact heavily used and exploited by different economic activities which have, to greater or lesser extent, environmental impacts. Attention for marine environmental challenges has grown, and is nowadays

  12. Estimating decadal variability in sea level from tide gauge records: An application to the North Sea

    NARCIS (Netherlands)

    Frederikse, Thomas; Riva, R.E.M.; Slobbe, Cornelis; Broerse, D.B.T.; Verlaan, Martin

    2016-01-01

    One of the primary observational data sets of sea level is represented by the tide gauge record. We propose a new method to estimate variability on decadal time scales from tide gauge data by using a state space formulation, which couples the direct observations to a predefined state space model by

  13. Estimating decadal variability in sea level from tide gauge records : An application to the North Sea

    NARCIS (Netherlands)

    Frederikse, T.; Riva, R.E.M.; Slobbe, D.C.; Broerse, D.B.T.; Verlaan, M.

    2016-01-01

    One of the primary observational data sets of sea level is represented by the tide gauge record. We propose a new method to estimate variability on decadal time scales from tide gauge data by using a state space formulation, which couples the direct observations to a predefined state space model

  14. Phytoplankton, chemical, physical, and other data were collected using bottle, CTD casts, and other instruments in the North Sea as part of the North Sea Project, 15 April 1988 - 30 July 1991 (NODC Accession 9300008)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Phytoplankton, chemical, physical, and other data were collected using bottle, current meter, net, pump, and CTD casts in the North Sea from April 15, 1988 to July...

  15. Nutrients, chlorophyll, fractional primary productivity in water column of the North Arabian Sea in support of the North Arabian Sea Environment and Ecosystem Research from 1992-1994 (NODC Accession 0000778)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Five cruises were carried out under the Pak-US cooperative project 'North Arabian Sea Environment and Ecosystem Research' (NASEER) from 1992-1994. The main objective...

  16. Integrated management plan for the North Sea and the Skagerrak: Impact assessment for renewable energy production in the North Sea; Helhetlig forvaltningsplan for Nordsjoen og Skagerrak. Konsekvenser av fornybar energiproduksjon i Nordsjoen.

    Energy Technology Data Exchange (ETDEWEB)

    Nybakke, Karen

    2011-07-01

    This is one of six sectorial assessments which will form the basis for a general management plan for the North Sea and the Skagerrak. The (environmental) impact assessment is limited to 6 areas.(Author)

  17. Transport process of Pu isotope in marginal seas of the western North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masatoshi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, 036-8564, Aomori (Japan); Zheng, Jian [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, 263-8555, Chiba (Japan)

    2014-07-01

    Significant quantities of Pu isotopes have been released into the marine environment as the result of atmospheric nuclear weapons testing. Most radionuclides globally dispersed in atmospheric nuclear weapons testing were released into the environment during the 1950's and 1960's. In the western North Pacific Ocean, the principal source can be further distinguished as two distinct sources of Pu: close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds (PPG) in the Marshall Islands and global stratospheric fallout. Since the {sup 240}Pu/{sup 239}Pu atom ratio is characteristic for the Pu emission source, information on Pu isotopic signature is very useful to better understand the transport process in the oceans and to identify the sources of Pu. The mean atom ratio of {sup 240}Pu/{sup 239}Pu from the global stratospheric fallout is 0.180 ±0.014 based on soil sample data, whereas that from close-in tropospheric fallout from the PPG is 0.33 - 0.36. The {sup 240}Pu/{sup 239}Pu atom ratios in seawater samples collected in marginal seas of the western North Pacific Ocean will provide important and useful data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The objectives of this study were to measure the {sup 239+240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios in seawater from the Sea of Okhotsk, Japan Sea, South China Sea and Sulu Sea and to discuss the transport process of Pu. Large-volume seawater samples (250 L each) were collected from the surface to the bottom in marginal seas of the western North Pacific Ocean with acoustically triggered quadruple PVC sampling bottles during the R/V Hakuho-Maru cruise. The {sup 239}Pu and {sup 240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. In

  18. Larval growth and drift pattern and the separation of herring spawning groups in the North Sea

    DEFF Research Database (Denmark)

    Munk, Peter; Christensen, Villy

    1990-01-01

    Data from two internationally co-ordinated survey programmes are used in an attempt to display the events in the early life that took place during the 'recovery period' of the North Sea herring stock, 1979-1986. During the period, an increasing importance of the spawning grounds off Buchan and off...... Yorkshire is evident from distributions of newly hatched herring larvae. The dramatic changes in relative importance of spawning grounds are traced in the data on both late larvae (6 months old) and juveniles (18 months old). The onset of extended spawning off Buchan and off Yorkshire was followed...... in the relative contributions from spawning grounds apparently influence the overall spatial distribution as well as size composition of larval and juvenile North Sea herring. The findings indicate that groups of larvae retain, to a large extent, separate distributions until metamorphosis, and point to larval...

  19. Assessments of the lesser sandeel ( Ammodytes marinus ) in the North Sea based on revised stock divisions

    DEFF Research Database (Denmark)

    Pedersen, S.A.; Lewy, Peter; Wright, P.

    1999-01-01

    effort, catch per unit effort, yield, fishing and natural mortality. A better understanding of sandeel growth is important for stock and catch predictions because previous studies indicate that the variability of mean weight-at-age is one of the most important factors influencing the precision......Recent investigations suggest that the current treatment of North Sea sandeel (Ammodytes marinus) as a single unit stock may have little biological basis. In order to study regional effects of the fishery on North Sea lesser sandeel it may therefore be important to assess stock dynamics...... of predictions. The Danish weight-at-age data of sandeel are re- analysed to estimate the mean weight-at-age in the catch and the stock and the precision of the estimates. The reliability of the sandeel assessments is discussed in relation to the data sources available and to the knowledge of sandeel biology...

  20. Spectral Properties of ENVISAT ASAR and QuikSCAT Surface Winds in the North Sea

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Larsén, Xiaoli Guo; Badger, Merete

    2013-01-01

    as an increase in spectral density over similar wavenumber ranges as the spatial resolution increases. The 600-m SAR wind product reveals a range of wavenumbers in which the exchange processes between micro- and meso-scales occur; this range is not captured by the wind products with a resolution of 1.5 km......Spectra derived from ENVISAT Advanced Synthetic Aperture Radar (ASAR) and QuikSCAT near-surface ocean winds are investigated over the North Sea. The two sensors offer a wide range of spatial resolutions, from 600 m to 25 km, with different spatial coverage over the area of interest. This provides...... a unique opportunity to study the impact of the spatial resolution on the spectral properties of the wind over a wide range of length scales. Initially, a sub-domain in the North Sea is chosen, due to the overlap of 87 wind scenes from both sensors. The impact of the spatial resolution is manifested...

  1. Recruitment decline in North Sea herring is accompanied by reduced larval growth rates

    DEFF Research Database (Denmark)

    Payne, Mark; Ross, Stine Dalmann; Worsøe Clausen, Lotte

    2013-01-01

    The stock of North Sea autumn spawning herring (Clupea harengus L.) has shown an unprecedented sequence of ten years of sharply reduced recruitment, in spite of a high spawning biomass. Recent work has identified this below-expected recruitment as being determined during the larval phase: however...... rate of 8%, concurrent with the reduced larval survival and recruitment, was identified: after correcting for the effect of other explanatory variables (e.g. temperature changes), the gross reduction was found to be 12%. This reduction is most probably due to changes in either the amount or quality...... and larvae survival, thereby narrowing the range of potential mechanisms underlying the observed reduction in the recruitment of North Sea autumn spawning herring...

  2. Closing the Gaps in Offshore P&A: Lessons Learned From the North Sea

    Science.gov (United States)

    Torsater, M.

    2017-12-01

    This talk will give an overview of the major challenges related to offshore well plugging and abandonment (P&A) with examples from the North Sea. The talk will outline why today's P&A operations are so time consuming and expensive, and it will point out current technology gaps and issues related to standards and regulations in the North Sea countries. Emerging P&A solutions will be discussed, and results from large ongoing research projects in Norway will be shared. Special emphasis will be given to promising new concepts, such as using creeping shale formations as permanent well barriers, and using thermal methods for removal of tubing and casing. The long-term aspects of well plugging will also be discussed, together with methods available for minimizing leakage risk.

  3. Detection of low numbers of microplastics in North Sea fish using strict quality assurance criteria.

    Science.gov (United States)

    Hermsen, Enya; Pompe, Renske; Besseling, Ellen; Koelmans, Albert A

    2017-09-15

    We investigated 400 individual fish of four North Sea species: Atlantic Herring, Sprat, Common Dab, and Whiting on ingestion of >20μm microplastic. Strict quality assurance criteria were followed in order to control contamination during the study. Two plastic particles were found in only 1 (a Sprat) out of 400 individuals (0.25%, with a 95% confidence interval of 0.09-1.1%). The particles were identified to consist of polymethylmethacrylate (PMMA) through FTIR spectroscopy. No contamination occurred during the study, showing the method applied to be suitable for microplastic ingestion studies in biota. We discuss the low particle count for North Sea fish with those in other studies and suggest a relation between reported particle count and degree of quality assurance applied. Microplastic ingestion by fish may be less common than thought initially, with low incidence shown in this study, and other studies adhering to strict quality assurance criteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Observation and analysis of tidal and residual current in the North Yellow Sea in the spring

    Science.gov (United States)

    Miao, Qingsheng; Yang, Jinkun; Yang, Yang; Wan, Fangfang; Yu, Jia

    2018-02-01

    In order to study the current characteristics of the North Yellow Sea (NYS), 4 moored ADCPs (Acoustic Doppler Current Profilers) were deployed and Current characteristics were analyzed based on the observations. Results show that tidal current is the dominant and M2 is the main constituent. Shallow water constituents are obvious in the near-shore area, and tidal current ellipses directions have relations with topography. Residual currents in the Bohai Strait point to the Bohai Sea interior and the magnitude have a connection with terrain. Residual current in south NYS can be divided into two layers, and energy of residual current only accounts for about 13% of the total energy. Barotropic eddy kinetic energy plays a major role and the average in NYS accounts for 87%, baroclinic mean kinetic energy is larger in north NYS, in other regions barotropic mean kinetic energy take the leading position.

  5. Early Permian intrusions in the Paleozoic sediments of the Eastern North Sea area

    DEFF Research Database (Denmark)

    Clausen, O.R.; Andresen, Katrine Juul; Rasmussen, Jens Andreas

    in the Northern Permian Basin which in the eastern North Sea is separated from the Southern Permian Basin by the Ringkøbing-Fyn High. The Permian basins were initiated during thermal subsidence following a late Carboniferous- early Permian rifting phase associated with extensive igneous activity recorded across...... the entire North Sea Basin. The easternmost intrusions and extrusions have been associated to the “Skagerrak-Centered Large Igneous Province” that has an early Permian age of c. 297 Ma. Compared to the Southern Permian Basin which historically has been intensely investigated because of the known presence...... of hydrocarbons within the Paleozoic sediments, the Northern Permian Basin has gained much less interest outside the hydrocarbon producing Mesozoic graben systems. This is mainly due to an apparent lack of potential source rocks. A major E-W striking northward dipping fault system characterizes the study area...

  6. Shifts in North Sea forage fish productivity and potential fisheries yield

    DEFF Research Database (Denmark)

    Worsøe Clausen, Lotte; Rindorf, Anna; van Deurs, Mikael

    2018-01-01

    productivity. Furthermore, from an ecosystem-based fisheries management perspective, a link between functional complementarity and productivity, indicates that ecosystem resilience may decline with productivity. Based on this, we advise that system productivity, perhaps monitored as forage fish growth, becomes......1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature......, the associated bottom-up effects and consequences for fisheries remain largely unidentified. 2. We investigated the temporal development in forage fish productivity and the associated influence on fisheries yield of herring, sprat, Norway pout and sandeel in the North Sea. Using principal component analysis, we...

  7. Mixed fisheries forecasts—lessons learned from their initial application to North Sea fisheries

    DEFF Research Database (Denmark)

    Holmes, S.J.; Ulrich, Clara; Reeves, S.A.

    2012-01-01

    the work with the existing single‐stock assessments. The explicit representation of the complexity of the fisheries also raises questions about the extent to which mixed fisheries science can be used to give ”advice” in the traditional sense. This paper addresses the challenges and issues that have arisen......Mixed fisheries and technical interactions in European fisheries have been a subject of research for many years. The establishment in 2010 of an ICES Working Group tasked with producing annual mixed fisheries forecasts and advice for North Sea demersal fisheries represents a commitment to use...... these approaches in routine scientific advice for the first time. The demersal fisheries of the North Sea provide a particularly interesting context for this work because of their high complexity in terms of the numbers of fleets, gears, métiers, and species involved, and also because mixedfishery effects have...

  8. Cenozoic structures and the tectonic evolution of the eastern North Sea

    DEFF Research Database (Denmark)

    Clausen, O.R.; Nielsen, S.B.; Egholm, D.L.

    2011-01-01

    Abundant seismic sections and well data from the Cenozoic succession in the eastern North Sea area generally reveal normal faulting, salt tectonics and localized tectonic inversion. However, inferences on the Cenozoic dynamic evolution of the region require thorough analysis of interactions between...... or cover tectonism took place. Our objectives are thus 1) to analyze the interaction between basement and cover structures, and if possible 2) to relate the structures to the regional tectonic evolution. The Zechstein evaporites pinch out onto the Ringkøbing-Fyn High, which in the eastern North Sea...... influencede.g. Miocene deposition and controlled the generation of second order faults. The latter detached along the top Chalk Group due to the topography generated during faulting, i.e. they are second order detachment surfaces. We conclude that the regional tectonic significance of the Cenozoic structures...

  9. Postglacial sedimentary regime around northern Sylt, South-eastern North Sea, based on shallow seismic evidence

    DEFF Research Database (Denmark)

    Boldreel, Lars Ole; Kuijpers, Antoon; Madsen, Emil B

    2010-01-01

    , in the outer delta, a dune field suggesting westerly-directed sediment transport is identified. The two dune fields appear to be separated by minor indefinite bed forms. The northern part of the Lister Tief is characterised by the presence of a channel with a depth of 20-30 mbsf (meter below sea level) (30......-40 msec TWT (Two Way Traveltime)) and displaying erosion towards the north. At the western termination of the channel the sediment transport pathway appears to be divided into two directions; one towards the outer delta, and one towards the sediment depocenter SW of Rømø. The Lister Ley is characterized......During the past 5 years the coastal zone offshore the northern part of the island of Sylt, has been investigated by sparker seismics and high-resolution subbottom profiling. The North Sea sector of the area is characterized by northward-directed sediment bypass as a result of strong long...

  10. SOLVENT-BASED ENHANCED OIL RECOVERY PROCESSES TO DEVELOP WEST SAK ALASKA NORTH SLOPE HEAVY OIL RESOURCES

    Energy Technology Data Exchange (ETDEWEB)

    David O. Ogbe; Tao Zhu

    2004-01-01

    A one-year research program is conducted to evaluate the feasibility of applying solvent-based enhanced oil recovery processes to develop West Sak and Ugnu heavy oil resources found on the Alaska North Slope (ANS). The project objective is to conduct research to develop technology to produce and market the 300-3000 cp oil in the West Sak and Ugnu sands. During the first phase of the research, background information was collected, and experimental and numerical studies of vapor extraction process (VAPEX) in West Sak and Ugnu are conducted. The experimental study is designed to foster understanding of the processes governing vapor chamber formation and growth, and to optimize oil recovery. A specially designed core-holder and a computed tomography (CT) scanner was used to measure the in-situ distribution of phases. Numerical simulation study of VAPEX was initiated during the first year. The numerical work completed during this period includes setting up a numerical model and using the analog data to simulate lab experiments of the VAPEX process. The goal was to understand the mechanisms governing the VAPEX process. Additional work is recommended to expand the VAPEX numerical study using actual field data obtained from Alaska North Slope.

  11. 77 FR 75119 - Dakota Prairie Grasslands, North Dakota; Oil and Gas Development Supplemental Environmental...

    Science.gov (United States)

    2012-12-19

    ... DEPARTMENT OF AGRICULTURE Forest Service Dakota Prairie Grasslands, North Dakota; Oil and Gas... to prepare a supplemental environmental impact statement. SUMMARY: In June of 2003, the Dakota... Dakota Prairie Grasslands Land and Resource Management Plan, based on the 2001 Northern Great Plains...

  12. A North Sea approach for Mexico?; El marco Mar del Norte para Mexico?

    Energy Technology Data Exchange (ETDEWEB)

    Baker, George [ENERGIA.com, United States (United States)

    2006-11-15

    The probable existence of oil and gas deposits in the border territory between Mexico and the United States has waked up an enormous restlessness given the lack of agreements and stipulations on the handling of such deposits; cases like this one have occurred in other parts of the globe and it is indeed the intention of this article to show how the agreement decided on the North Sea can be applied in the case of Mexico. The bilateral characteristics of this agreement conformed by incentives and openings to the market, require the cooperation of different offices and governmental sectors from the federal government to make a series of possible stipulations that regulate the treaty and allow different oil companies a substantial interaction that profits the owners on both sides of the border. In Mexico the responsibility to put in action projects of this type corresponds to the legislative power in complicity with the secretariats of Foreign Affairs and Work. The present action models and the monopoly of Petroleos Mexicanos (PEMEX) in Mexico have only managed to suspend the development of the country in this sector and to maintain the oil industry development in a mediocre and deteriorated level. The benefits of such an adjustment would extend beyond obtaining a bilateral development for the involved countries; nevertheless we remember that the government of the United States is not to the compass of the governments pro-unification of borders. In order to begin the unification of the border regions, Mexico must document the location of border wells, nevertheless even though any agreement could be reached, years would have to pass before PEMEX develops the appropriate technology to operate its part of the deposits. [Spanish] La probable existencia de yacimientos de petroleo y gas en el territorio fronterizo entre Mexico y Estados Unidos ha despertado una enorme inquietud dada la falta de acuerdos y estipulaciones sobre la manipulacion de tales yacimientos; casos como

  13. Temperature Effects on Stiffness Moduli of Reservoir Sandstone from the Deep North Sea

    DEFF Research Database (Denmark)

    Orlander, Tobias; Andreassen, Katrine Alling; Fabricius, Ida Lykke

    We investigate effect of testing temperature on the dynamic frame stiffness of quartz-bearing North Sea sandstone from depths of 5 km. We show that at low stress levels, the rock frame stiffens with increasing temperature and we propose an explanation for the controlling mechanisms. While...... temperature. This is unfortunate and hence, we designed a testing program with the intension of separating and quantifying effects of temperature and stress, specifically for the sandstone material subject to this study....

  14. Simulated North Atlantic-Nordic Seas water mass exchanges in an isopycnic coordinate OGCM

    OpenAIRE

    Nilsen, Jan Even Øie; Gao, Yongqi; Drange, Helge; Furevik, Tore; Bentsen, Mats

    2003-01-01

    The variability in the volume exchanges between the North Atlantic and the Nordic Seas during the last 50 years is investigated using a synoptic forced, global version of the Miami Isopycnic Coordinate Ocean Model (MICOM). The simulated volume fluxes agree with the existing observations. The net volume flux across the Faroe-Shetland Channel (FSC) is positively correlated with the net flux through the Denmark Strait (DS; R = 0.74 for 3 years low pass filtering), but negatively correlated with ...

  15. Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Franeker, Jan A. van, E-mail: Jan.vanfraneker@wur.nl [IMARES Institute for Marine Resources and Ecosystem Studies, Wageningen-UR, PO Box 167, 1790AD Den Burg, Texel (Netherlands); Blaize, Christine [Le CHENE, Centre de Sauvegarde de la Faune Sauvage et Musee de la Nature, 12 Rue du Musee, F-76190 Allouville-Bellefosse (France); Danielsen, Johannis [Norouri i Sundum 7, FO-410 Kollafjorour (Faroe Islands); Fairclough, Keith [Fairclough Ecological Orkney FEO Viewforth, Swannay by Evie, Orkney, KW17 2NR, Scotland (United Kingdom); Gollan, Jane [Kermouroux, FR-56 470 Saint Philibert (France); Guse, Nils [Research and Technology Centre West coast FTZ, University of Kiel, Hafentoern 1, D-25761 Buesum (Germany); Hansen, Poul-Lindhard [Naturhistorisk Museum Skagen, Skagen Naturcenter, Flagbakkevej 30, DK-9990 Skagen (Denmark); Heubeck, Martin [University of Aberdeen (SOTEAG), Sumburgh Head Lighthouse, Virkie, Shetland ZE3 9JN, Scotland (United Kingdom); Jensen, Jens-Kjeld [Zoological conservator, I Geilini 37, FO-270 Nolsoy (Faroe Islands); Le Guillou, Gilles [Groupe Ornithologique Normand, 118 route d' ORCHER, F-76700 Gonfreville l' Orcher (France); Olsen, Bergur [Faroe Marine Research Institute c/o Natturugripasavnio, Futalag 40, FO-100 Torshavn (Faroe Islands); Olsen, Kare-Olav [Postveien 43, N-4563 Borhaug (Norway); Pedersen, John [Skagen Uddannelsescenter SUC, Vestmolen 15, DK-9990 Skagen (Denmark); Stienen, Eric W.M. [Research Institute for Nature and Forest, Kliniekstraat 25, B-1070 Brussels (Belgium); Turner, Daniel M. [9 Haswell Gardens, North Shields, Tyne and Wear, NE30 2DP, England (United Kingdom)

    2011-10-15

    The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of plastic in the stomach. During 2003-2007, 95% of 1295 fulmars sampled in the North Sea had plastic in the stomach (on average 35 pieces weighing 0.31 g) and the critical level of 0.1 g of plastic was exceeded by 58% of birds, with regional variations ranging from 48 to 78%. Long term data for the Netherlands since the 1980s show a decrease of industrial, but an increase of user plastics, with shipping and fisheries as the main sources. The EcoQO is now also used as an indicator for Good Environmental Status in the European Marine Strategy Framework Directive. - Highlights: > Trends in marine debris can be monitored by plastics in stomachs of seabirds. > In the North Sea 95% of Fulmars has plastic in the stomach (35 particles; 0.31 g). > The policy target is that less than 10% of Fulmars has over 0.1 g of plastic. > Currently 58% of North Sea fulmars exceeds the 0.1 g critical limit. > Over the past 30 years industrial plastics decreased and user plastic increased. - Trends and patterns in the abundance of plastics in northern fulmar stomachs show that seabirds can be a valuable tool for monitoring marine litter.

  16. What can we learn from the stock collapse and recovery of North Sea herring? A review

    DEFF Research Database (Denmark)

    Dickey-Collas, M.; Nash, R.D.M.; Brunel, T.

    The collapse and recovery of North Sea herring in the latter half of the twentieth century hasbeen well documented. With hindsight and the benefit of almost 40 years of extra data andstudies, we can now obtain a clear view of the impact of the collapse and the recovery onthe stock, the fishery, a...... the relevant lessons for the management of other fish stocks and other marine shelf ecosystems...

  17. Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea

    International Nuclear Information System (INIS)

    Franeker, Jan A. van; Blaize, Christine; Danielsen, Johannis; Fairclough, Keith; Gollan, Jane; Guse, Nils; Hansen, Poul-Lindhard; Heubeck, Martin; Jensen, Jens-Kjeld; Le Guillou, Gilles; Olsen, Bergur; Olsen, Kare-Olav; Pedersen, John; Stienen, Eric W.M.; Turner, Daniel M.

    2011-01-01

    The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of plastic in the stomach. During 2003-2007, 95% of 1295 fulmars sampled in the North Sea had plastic in the stomach (on average 35 pieces weighing 0.31 g) and the critical level of 0.1 g of plastic was exceeded by 58% of birds, with regional variations ranging from 48 to 78%. Long term data for the Netherlands since the 1980s show a decrease of industrial, but an increase of user plastics, with shipping and fisheries as the main sources. The EcoQO is now also used as an indicator for Good Environmental Status in the European Marine Strategy Framework Directive. - Highlights: → Trends in marine debris can be monitored by plastics in stomachs of seabirds. → In the North Sea 95% of Fulmars has plastic in the stomach (35 particles; 0.31 g). → The policy target is that less than 10% of Fulmars has over 0.1 g of plastic. → Currently 58% of North Sea fulmars exceeds the 0.1 g critical limit. → Over the past 30 years industrial plastics decreased and user plastic increased. - Trends and patterns in the abundance of plastics in northern fulmar stomachs show that seabirds can be a valuable tool for monitoring marine litter.

  18. The discard ban and its impact on the MSY objective on fisheries-the North Sea

    DEFF Research Database (Denmark)

    Ulrich, Clara

    2016-01-01

    North Sea fisheries are characterised by numerous biological and technical interactions, which create difficulties in identifying MSY targets and achieving those for all stocks simultaneously. The landing obligation may reinforce these issues, as ‘choke’ effects might be triggered by the least...... productive stocks. A flexible management approach can help achieve the multiple objectives, but this requires trade-offs to be made. The ecological benefits of reducing fishing mortality are likely larger than those from the landing obligation itself...

  19. Polonium-210 in mussels and fish from the Baltic-North Sea estuary

    DEFF Research Database (Denmark)

    Dahlgaard, H.

    1996-01-01

    Polonium-210 has been measured in Danish fish meat caught in the North Sea, the Kattegat and the Baltic in 1991-1994. Average values of 0.35, 0.65 and 0.96 Bq Po-210 kg(-1) fresh weight were observed for cod, herring and plaice fillets, respectively. The difference between species is statistically...... in fish and mussels may represent a natural baseline. Copyright (C) 1996 Elsevier Science Ltd....

  20. Larval nematodes in stomach wall granulomas of smelt Osmerus eperlanus from the German North Sea coast

    OpenAIRE

    Obiekezie, A. I.; Lick, Roland R.; Kerstan, Susanne L.; Möller, Heino

    1992-01-01

    Occurrence of stomach wall granulomas in European smelt was studled at 6 locations along the German North Sea coast. Identification of larval nematodes inhabiting these granulomas is provided for the first time. Three species, isolated by pepsin-HC1 digestion, are involved: Hysterothylacium cf. cornutum, Cosmocephalus obvelatus and Paracuaria tridentata. 72% of all stomachs examined were affected. The ratio of number of granulomas to number of the 3 larval species free in the mesentery was 1:...