Oil Spills in Ice: Some Cleanup Options

Reports measures used to dispose of a 367,000-gal diesel oil and gasoline spill in Deception Bay, Quebec (western Hudson Strait) after a slide of snow and water through a tank farm. The oil was pumped on sea ice and burned at a location away from the tank farm and tundra

An Oiled Arctic Shore

A portion of the fuel oil spilled into the harbour at Resolute, Northwest Territories, late in August 1970 went ashore there and, as yet, a firm arrangement concerning cleanup has not been made. The oiling occurred mainly on the upper portion of the intertidal zone, but not above high water .... The oil was believed to have been a mixture of diesel fuel and a heavier fuel, perhaps as heavy as a Bunker C type, but was generally "light" enough so that some penetration into the gravel occurred. ... Apparently the spill occurred from a tanker with a cargo comprising a variety of fuel oils which, during a hose or tank cleaning operation, discharged an oil waste onto the water surface at a position just off the tank farm. At the time (believed to be late on 24 August or early on 25 August), the harbour contained a considerable amount of ice, apparently as much as 8 to 9 tenths ice cover in some places, which in turn contained the oil and limited its movement to the immediate shore to the north and east. A portion of the ice became quite heavily stained with oil and some of this ice eventually moved out of the harbour with the northerly winds of 1 September. However, ablation of a portion of the stained ice occurred while it was grounded on the intertidal zone causing somewhat heavier oiling there and patchiness in the distribution of oil which was visually quite evident on 3 September .... By 1 October the intertidal zone was covered with the ice and only a light stain was visible at the high water line. Recent experience and experiment have demonstrated that ice cover can provide effective control of spilled oil. It seems that the containment at Resolute was also quite effective and would have permitted consideration of a number of cleanup options. For example, the oil might have been pumped into containers ashore or into a ship or barge, or pumped in discrete amounts to other areas of ice cover in a direction away from the tank farm and burned. ..

A Freshwater Budget of the Gulf of Boothia, Northwest Territories

A freshwater budget for the Gulf of Boothia (here considered to include Prince Regent Inlet) was estimated from oceanographic data available for the Canadian Arctic using a formula derived by Tully: integral of S(z) dz between limits L and 0 divided by S*L where C is the fraction of freshwater to the depth L, L is the depth at which the salinity attained S* or the depth to the bottom if the salinity there was less than S*, S(z) is the salinity at depth z and S* is the base salinity, in this budget taken to be 33.8 per mil. For each station occupied in 1961 and 1962 the amount of freshwater in metres, CL, was obtained. The result for 1962 is shown in Fig. 1. Sources of freshwater include direct precipitation, runoff, advection of less saline water and of ice, and condensation at the surface. It may be removed by evaporation and advection. We assumed that condensation is so small it may be neglected and that the rates of precipitation and evaporation are the same over the land as over the water. The mean precipitation in the region of the Gulf of Boothia is usually less than 20 cm/year and in nearby Barrow Strait it was estimated that the evaporation was about 8 cm/year in 1962. If the latter value is representative of the Gulf of Boothia and its drainage basin, the excess of precipitation over evaporation is about 12 cm/year. The estimate is supported by 1965 streamflow measurements of the Back River; for this basin the excess of precipitation over evaporation is about 17 cm/year. It seems that the water surplus for the Gulf of Boothia drainage basin is somewhat less so the estimate of 12 cm/year appears reasonable. As the area of the drainage basin is one and one quarter that of the gulf, runoff would add 15 cm/year to the freshwater of the gulf. Combining the gains and losses we estimate the net annual input at the surface to be 27 cm/year. If the 8 metres of freshwater estimated to occur in the gulf (Fig. 1) were due to the annual gain, it would represent an accumulation of close to 30 years. As free exchange with Lancaster Sound and beyond is possible, such a long period of accumulation seems unrealistic. There is no reason to believe that the accumulation is related to an excess of imported over exported ice, indeed export may exceed import, but data which would permit a quantitative assessment are not available. Examination of ice reconnaissance data in each year, for example that for 1967, indicates that, while movement of ice occurs from northern parts of the gulf to the south, the ice conditions observed within the system could be due entirely to ice formed there. It seems likely therefore that the accumulation is due to advection of low salinity water and that a direct relation exists between the depth of freshwater in the gulf and that calculated to occur in the archipelago to the west and in the Arctic Ocean (Fig. 1). It is generally considered that a net surface movement from west to east occurs through the archipelago; the freshwater budget provides support for this view

Variability of the Tide at Some Sites in the Canadian Arctic

Various techniques are used to detect the possible distortion of the tide by the presence of an ice cover at some gauging sites in the Canadian Arctic. Some stations are apparently unaffected, while those around the periphery of Amundsen Gulf and Hudson Bay experience larger tides during the annual period of open water and the time of arrival of the tide is altered

Sea Level at Port Leopold, N.W.T. in 1848

Forty-seven days of hourly sea level and atmospheric pressure data collected in 1848 at Port Leopold, N.W.T., are analyzed using modern time series computation techniques. Tidal analysis reveals a mixed tide but mainly semi-diurnal. A detailed analysis of the tidal data reveals that the time-keeping of the record was as good as today's standard. A high correlation between hourly sea level and atmospheric pressure data demonstrates the inverse barometric effect.Key words: Arctic, sea level, tide, ice cover, free oscillation, lowpass, scatter diagram, time series, Resolute, Port LeopoldMots clés: Arctique, Niveau de la mer, marée, couvert de glace, oscillation libre, goulet, diagramme de dispersion, series chronologiques, Resolute, Port Léopol

Bacterioplankton responses to riverine and atmospheric inputs in a coastal upwelling system (Ría de Vigo, NW Spain)

Original research paperAnthropogenic pressures are changing the magnitude and nature of matter inputs into the ocean. The Ría de Vigo (NW Spain) is a highly productive and dynamic coastal system that is likely affected by such alterations. Previous nutrient-addition microcosm experiments conducted during contrasting hydrographic conditions suggested that heterotrophic bacteria are limited by organic carbon (C) and occasionally co-limited by inorganic nutrients in this coastal area. In order to assess short-term responses in biomass, production, and respiration of heterotrophic bacteria from the Ría de Vigo to increasing amounts of natural inputs of matter, we conducted 6 microcosm experiments, wherein surface seawater collected in spring, summer, and autumn was mixed with increasing amounts of dissolved natural matter concentrates from riverine and atmospheric origin. Simultaneous experiments with controlled inorganic and/or organic additions indicated that bacteria were co-limited by inorganic nutrients and C in spring and summer and primarily limited by C in autumn. Production responded more than biomass to increasing inputs of matter, whereas respiration did not change. The bacterial production response to increasing dissolved organic C load associated with riverine and atmospheric inputs was strongly related to the relative phosphorus (P) content of the dissolved matter concentrates. Our data suggest that bacterial production might decrease with the increase of P-deficient allochthonous matter inputs, which would have important biogeochemical consequences for C cycling in coastal areas.Spanish Ministry of Science and Innovation, MINECO, CSIC, Xunta of Galicia and European Union (Marie Curie Grants)Versión del edito

Identification of Multiple Subsets of Ventral Interneurons and Differential Distribution along the Rostrocaudal Axis of the Developing Spinal Cord

The spinal cord contains neuronal circuits termed Central Pattern Generators (CPGs) that coordinate rhythmic motor activities. CPG circuits consist of motor neurons and multiple interneuron cell types, many of which are derived from four distinct cardinal classes of ventral interneurons, called V0, V1, V2 and V3. While significant progress has been made on elucidating the molecular and genetic mechanisms that control ventral interneuron differentiation, little is known about their distribution along the antero-posterior axis of the spinal cord and their diversification. Here, we report that V0, V1 and V2 interneurons exhibit distinct organizational patterns at brachial, thoracic and lumbar levels of the developing spinal cord. In addition, we demonstrate that each cardinal class of ventral interneurons can be subdivided into several subsets according to the combinatorial expression of different sets of transcription factors, and that these subsets are differentially distributed along the rostrocaudal axis of the spinal cord. This comprehensive molecular profiling of ventral interneurons provides an important resource for investigating neuronal diversification in the developing spinal cord and for understanding the contribution of specific interneuron subsets on CPG circuits and motor control

The Muonium Atom as a Probe of Physics beyond the Standard Model

The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium ($M = \mu^+ e^-$) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure

Assessing the authority of political office-holders: the leadership capital index

This article argues that the extent to which political office-holders can effectively attain and wield authority is a function of the stock of ‘leadership capital.’ Drawing on the concept of political capital, we define leadership capital as aggregate authority composed of three dimensions: skills; relations; and reputation of a leader. Leadership capital ebbs and flows over time within a trajectory of acquisition, expenditure and inevitable depreciation. We present a Leadership Capital Index (LCI) that systematically maps out the three broad areas combining concrete measures with interpretive aspects. This can be used as a tool for systematically tracking and comparing the political fortunes of leaders in a way that is both more nuanced and robust than exclusive reliance on the latest approval ratings. We offer an illustrative case study of Tony Blair demonstrating the LCI. We conclude by discerning several promising paths for future development of the LCI

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results