The circulation of the Indian Ocean at 32°S     

Elaine L. McDonagh  Harry L. Bryden  Brian A. King  Richard J. Sanders 《Progress in Oceanography》2008,79(1):20-36

Using inverse methods a circulation for a new section along 32°S in the Indian Ocean is derived with a maximum in the overturning stream function (or deep overturning) of 10.3 Sv at 3310 m. Shipboard and Lowered Acoustic Doppler Current Profiler (ADCP) data are used to inform the choice of reference level velocity for the initial geostrophic field. Our preferred solution includes a silicate constraint (−312 ± 380 kmol s⁻¹) consistent with an Indonesian throughflow of 12 Sv. The overturning changes from 12.3 Sv at 3270 m when the silicate constraint is omitted to 10.3 Sv when it is included. The deep overturning varies by only ±0.7 Sv as the silicate constraint varies from +68 to −692 kmol s⁻¹, and by ±0.3 Sv as the net flux across the section, driven by the Indonesian throughflow, varies from −7 to −17 Sv with an appropriately scaled silicate flux constraint. Thus, the overturning is insensitive to the size of the Indonesian throughflow and silicate constraint within their apriori uncertainties. We find that the use of the ADCP data adds significant detail to the horizontal circulation. These resolved circulations include the Agulhas Undercurrent, deep cyclonic gyres and deep fronts, features evidenced by long term integrators of the flow such as current meter and float measurements as well as water properties.  相似文献   

Managing shark fishermen in southern Australia: A critique     

Peter D. Dwyer  Tanya J. King  Monica Minnegal 《Marine Policy》2008

This paper analyses effects of a shift from input to output controls in Australia's Southern Shark Fishery. We show that the use of two management tools—individual transferable quotas and a “partnership approach”—was flawed and argue that primary contributing causes were the unjustified expectation that quota management would serve as a ‘technical fix’ to a variety of presumed problems, the discounting of social effects and the extreme lack of stability in the organizational structure within which this fishery was situated.  相似文献   

Macroparasites of angelfish Brama brama (Bonnaterre, 1788) in the southern Benguela Current ecosystem     

AL Mackintosh  CC Reed  MAI Nunkoo  PH King  CD van der Lingen 《African Journal of Marine Science》2018,40(3):245-252

The angelfish Brama brama is a mesopelagic species distributed circumglobally in temperate to warm-temperate waters, including continental-shelf-edge and upper-slope waters of the Benguela Current ecosystem. Little is known about the parasite assemblage of Benguela B. brama, with only three parasite taxa having previously been documented from this species in the southern Benguela. This study describes the macroparasites recorded from 35 B. brama collected during research surveys off the west coast of South Africa in 2015 and 2016. A total of six macroparasite taxa were documented, including the nematode Anisakis pegreffii, the copepod Hatschekia conifera, the cestode Hepatoxylon trichiuri, an acanthocephalan from the genus Rhadinorhynchus, a monogenean from the family Diclidophoridae, and an unidentified species. Three of these (He. trichiuri, Rhadinorhynchus sp. and the unidentified species) had not previously been found to infect B. brama. The most prevalent macroparasite taxa were A. pegreffii (94%), the unidentified species (71%) and Ha. conifera (60%). Two of the parasites, Ha. conifera and He. trichiuri, showed seasonal variation in infection, and infection with the latter was positively correlated with host length. These findings increase our knowledge of B. brama biology and contribute to our understanding of the biodiversity of the southern Benguela ecosystem.  相似文献   

Biological structures as a source of habitat heterogeneity and biodiversity on the deep ocean margins   总被引：1，自引：0，他引：1  

Lene Buhl-Mortensen  Ann Vanreusel  rew J. Gooday  Lisa A. Levin  Imants G. Priede  Pål Buhl-Mortensen  Hendrik Gheerardyn  Nicola J. King  & Maarten Raes 《Marine Ecology》2010,31(1):21-50

Biological structures exert a major influence on species diversity at both local and regional scales on deep continental margins. Some organisms use other species as substrates for attachment, shelter, feeding or parasitism, but there may also be mutual benefits from the association. Here, we highlight the structural attributes and biotic effects of the habitats that corals, sea pens, sponges and xenophyophores offer other organisms. The environmental setting of the biological structures influences their species composition. The importance of benthic species as substrates seems to increase with depth as the complexity of the surrounding geological substrate and food supply decline. There are marked differences in the degree of mutualistic relationships between habitat-forming taxa. This is especially evident for scleractinian corals, which have high numbers of facultative associates (commensals) and few obligate associates (mutualists), and gorgonians, with their few commensals and many obligate associates. Size, flexibility and architectural complexity of the habitat-forming organism are positively related to species diversity for both sessile and mobile species. This is mainly evident for commensal species sharing a facultative relationship with their host. Habitat complexity is enhanced by the architecture of biological structures, as well as by biological interactions. Colony morphology has a great influence on feeding efficiency for suspension feeders. Suspension feeding, habitat-forming organisms modify the environment to optimize their food uptake. This environmental advantage is also passed on to associated filter-feeding species. These effects are poorly understood but represent key points for understanding ecosystems and biodiversity on continental margins. In this paper we explore the contributions of organisms and the biotic structures they create (rather than physical modifications) to habitat heterogeneity and diversity on the deep continental margins.  相似文献   

Balancing deformation in NW Borneo: Quantifying plate-scale vs. gravitational tectonics in a delta and deepwater fold-thrust belt system     

Rosalind C. King  Guillaume Backé  Christopher K. Morley  Richard R. Hillis  Mark R.P. Tingay 《Marine and Petroleum Geology》2010

Recent GPS measurements demonstrate that NW Borneo undergoes 4–6 mm of plate-scale shortening a year, which is not accommodated by plate-scale structures. The only geological structure in NW Borneo described to accommodate on-going shortening is the Baram Delta System located on the outer shelf to basin floor. Delta toe fold-thrust belts are commonly thought to be caused by margin-normal compressional stresses generated by margin-parallel upslope gravitational extension.  相似文献   

Rational noncompliance and the liquidation of Northeast groundfish resources     

Dennis M. King  Jon G. Sutinen 《Marine Policy》2010

The results of a 2007 survey of fishers, managers, scientists, and enforcement officials indicate that noncompliance is a significant problem in the Northeast multispecies groundfish (NEGF) fishery, as it has been for at least 20 years. The percent of total harvest taken illegally is estimated to be 12–24%, which is significantly higher than estimates of 6–14% in the 1980s. Thirty-seven percent of fishers, 61% of fishery managers and 80% of fishery enforcement staff believe that “the combined adverse impact of all violations on the health and manageability of fish resources” is significant, highly significant, or extremely significant. Many fishers believe that illegal fishing will prevent them from ever benefiting from stock rebuilding programs.  相似文献   

Solitary wave generation dynamics at Luzon Strait     

A. Warn-Varnas  J. Hawkins  K.G. Lamb  S. Piacsek  S. Chin-Bing  D. King  G. Burgos 《Ocean Modelling》2010,31(1-2):9-27

A high resolution modeling study is undertaken, with a 2.5-dimensional nonhydrostatic model, of the generation of internal waves induced by tidal motion over the ridges in Luzon Strait. The model is forced by the barotropic tidal components K1, M2, and O1. These tidal components, along with the initial density field, were extracted from data and models. As the barotropic tide moves over the Luzon Strait sills, there is a conversion of barotropic tidal energy into baroclinic tidal energy. Depressions are generated that propagate towards the Asian Seas International Acoustics Experiment (ASIAEX) test site on the Chinese continental shelf. Nonlinear effects steepen the depressions, frequency and amplitude dispersion set in, and disintegration into large amplitude solitary waves occurs. The effects of varying the initial density field, tidal component magnitudes, as well as adding a steady background current to represent the occasional excursions of the Kuroshio Current into the strait, are considered.Depressions are generated at each of the two sills in Luzon Strait which radiate away, steepening and evolving into internal solitary wave trains. Baroclinic fluxes of available potential energy, kinetic energy and linear are calculated for various parameter combinations. The solitary wave trains produced in the simulations generally consist of large amplitude wave trains alternating with small amplitude wave trains. During strong tidal flow, Kelvin–Helmholtz type instabilities can develop over the taller double-humped sill. The solitary waves propagating towards the ASIAEX test site have been observed to reach amplitudes of 120–250 m, depending on the tidal strength. ASIAEX observations indicate amplitudes up to 150 m and the Windy Island Experiment (WISE) measurements contain magnitudes over 200 m. The model results yield solitary wave amplitudes of 70–300 m and half widths of 0.60–3.25 km, depending on parameter values. These are in the range of observations. Measurements by Klymak et al. (2006), in the South China Sea, exhibit amplitudes of 170 m, half widths of 3 km and phase speeds of 2.9 m s^?1. Model predictions indicate that the solitary waves making up the wave packet each experience different background currents with strong near surface shear.The energy in the leading soliton of the large amplitude wave trains ranges between 1.8 and 9.0 GJ m^?1. The smaller value, produced using barotropic tidal currents based on the Oregon State University data base, is the same as the energy estimated to be in a solitary wave observed by Klymak et al. (2006). Estimates of the conversion of barotropic tidal energy into radiating internal wave energy yield conversion rates ranging between 3.6% and 8.3%.  相似文献   

Generation of correlated properties in heterogeneous porous media   总被引：1，自引：0，他引：1  

P. R. King  P. J. Smith 《Mathematical Geology》1988,20(7):863-877

The spatial distribution of rock properties in porous media, such as permeability and porosity, often is strongly variable. Therefore, these properties usefully may be considered as a random field. However, this variability is correlated frequently on length scales comparable to geological lengths (for example, scales of sand bodies or facies). To solve various engineering problems (for example, in the oil recovery process) numerical models of a porous medium often are used. A need exists then to understand correlated random fields and to generate them over discretized numerical grids. The paper describes the general mathematical methods required to do this, with one particular method (the nearest neighbor model) described in detail. How parameters of the mathematical model may be related to rock property statistics for the nearest neighbor model is shown. The method is described in detail in one, two, and three dimensions. Examples are given of how model parameters may be determined from real data.  相似文献   

Discussion of "What You Don't Find Isn't There, Or Is It? (or The absence of proof is not proof of absence),"Ground Water Monitoring & Remediation, v. 14, no. 1, pages 79–83, Winter 1994.     

James M. King 《Ground Water Monitoring & Remediation》1994,14(3):269-270

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A RELATIVE ORIENTATION FOR MOTOR VEHICLE ACCIDENT PHOTOGRAMMETRY     

B. A. King 《The Photogrammetric Record》1991,13(78):893-899

Relative orientations of eight stereomodels of a motor vehicle accident scene taken with stereometric cameras were made on an Adam Technology MPS-2 microphotogrammetric system. The most consistent results for the relative orientations were achieved with 12 pass points—six around the extremities and six in the centre of the format. Systematic errors in the direction normal to the photography were detected. Two methods to correct these errors were investigated—scaling of the camera base and computing a camera convergence correction. The best results were achieved with the convergence correction.  相似文献