Coral recruitment onto an experimental pulverised fuel ash-concrete artificial reef     

Lam KK 《Marine pollution bulletin》2003,46(5):642-653

An experimental artificial reef was deployed in December 1993 at Hoi Ha Wan Marine Park, Hong Kong. This is the first study documenting natural scleractinian coral recruitment onto a stabilised pulverised fuel ash (PFA)-concrete artificial reef. Visible recruits were first recorded 9-10 months after the placement of reef blocks, i.e., in the autumn of 1994. Two scleractinians, Oulastrea crispata and Culicia japonica, were recruited. The recruit density of the former was much greater than the latter. The spatial recruitment pattern of the corals was observed to be affected by the orientation of the attaching surface. O. crispata settled predominantly on the undersides of the reef blocks. There was an edge effect on O. crispata recruitment. C. japonica, however, had a preference for exposed surfaces. O. crispata did not show a preference for block composition whereas C. japonica favoured blocks with high (75% by volume) PFA levels. This shows that PFA-concrete is a potential substratum for artificial reef construction, especially when such reefs aim at rehabilitating corals.  相似文献   

Biofouling confounds the uptake of trace organic contaminants by semi-permeable membrane devices (SPMDs)     

Richardson BJ  Lam PK  Zheng GJ  McClellan KE  De Luca-Abbott SB 《Marine pollution bulletin》2002,44(12):1372-1379

The outer layers of layflat, low density polyethylene plastic tubing (the principal component of semi-permeable membrane devices, SPMDs) were biofouled at a clean site in Hong Kong coastal waters for periods of 1–4 weeks. Following pre-fouling, triolein was added to the SPMDs and, along with control (unfouled) devices, they were exposed to a range of organochlorine pesticides (-HCH, aldrin, p,p^′-DDT) and PAHs (anthracene, fluoranthene and benzo(a)pyrene) under laboratory conditions. Results showed that the uptake of contaminants by SPMDs was severely reduced by as much as 50% under fouling conditions in comparison to unfouled controls. The ultimate utility of SPMDs as passive monitors is thus reduced, although alternative measures, such as the use of permeability reference compounds may compensate, and allow for realistic evaluations of dissolved environmental concentrations in aquatic environments. However, due to the complexities involved in such procedures––especially as they need to be conducted on a case-by-case basis––the utility of SPMDs appears to be limited for estimates of bioavailability unless necessary calibrations are undertaken within each environment that the sampler is used.  相似文献   

The Enso-Fire Dynamic in Insular Southeast Asia     

Douglas O. fuller  Kevin Murphy 《Climatic change》2006,74(4):435-455

We examined the spatiotemporal patterns of fire in insular Southeast Asia from July 1996 to December 2001 using a set of consistent, nighttime fire observations provided by the Along Track Scanning Radiometer (ATSR) sensor. Monthly ATSR fire counts were analyzed relative to georeferenced climatic and land-cover data from a variety of sources. We found that fires were strongly correlated with Southern Oscillation Index (SOI) (r = ?0.75) and Niño 3.4 index (r = 0.72) in forested land-cover types within the equatorial belt (5.5^°S–5.5^°N). Cross-correlation analysis revealed that detrended SOI was modestly correlated (r = 0.42) with detrended monthly fire count with a positive lag of four months. However, our analysis also revealed that fire counts reached their maximum 6 months before the absolute maximum of SOI. Annual sums of SOI (∑_SOI) and fire counts revealed linearity for ∑_SOI≤ 0. Overall, the results suggest that ENSO indices may have limited predictive utility at a monthly time scale, but that temporal aggregation and additional fire observations may enhance our capacity to forecast fires in different cover types based on ENSO data.  相似文献   

Frequency distributions of transient regional climate change from perturbed physics ensembles of general circulation model simulations   总被引：1，自引：2，他引：1  

G. R. Harris  D. M. H. Sexton  B. B. B. Booth  M. Collins  J. M. Murphy  M. J. Webb 《Climate Dynamics》2006,27(4):357-375

Large ensembles of coupled atmosphere–ocean general circulation model (AOGCM) simulations are required to explore modelling uncertainty and make probabilistic predictions of future transient climate change at regional scales. These are not yet computationally feasible so we have developed a technique to emulate the response of such an ensemble by scaling equilibrium patterns of climate change derived from much cheaper “slab” model ensembles in which the atmospheric component of an AOGCM is coupled to a mixed-layer ocean. Climate feedback parameters are diagnosed for each member of a slab model ensemble and used to drive an energy balance model (EBM) to predict the time-dependent response of global surface temperature expected for different combinations of uncertain AOGCM parameters affecting atmospheric, land and sea-ice processes. The EBM projections are then used to scale normalised patterns of change derived for each slab member, and hence emulate the response of the relevant atmospheric model version when coupled to a dynamic ocean, in response to a 1% per annum increase in CO₂. The emulated responses are validated by comparison with predictions from a 17 member ensemble of AOGCM simulations, constructed from variants of HadCM3 using the same parameter combinations as 17 members of the slab model ensemble. Cross-validation permits estimation of the spatial and temporal dependence of emulation error, and also allows estimation of a correction field to correct discrepancies between the scaled equilibrium patterns and the transient response, reducing the emulation error. Emulated transient responses and their associated errors are obtained from the slab ensemble for 129 pseudo-HadCM3 versions containing multiple atmospheric parameter perturbations. These are combined to produce regional frequency distributions for the transient response of annual surface temperature change and boreal winter precipitation change. The technique can be extended to any surface climate variable demonstrating a scaleable, approximately linear response to forcing.  相似文献   

Grounding the virtual: The material effects of electronic grocery shopping     

Andrew J. Murphy 《Geoforum》2007,38(5):941-953

This paper addresses the materiality of computer-mediated retailing. The paper uncovers the “hidden geography” of e-commerce, considering how the seemingly simple act of doorstep food delivery is explicated in urban form, and in transportation and communication infrastructures. The paper categorises electronic grocery shopping (EGS) enterprises into three types: “bricks and clicks”, “pure-play” and the “infomediary”, and examines how each type of operation has been materialised in the urban landscape, and the infrastructure upon which each draws. The paper then considers the strategies EGS operations have used to offset the “killer costs” of logistics for electronic commerce. The paper concludes by considering how electronic grocery shopping is embedded within broader trends in consumer behaviour, and how these trends are manifested in the materiality of urban life. The paper argues that online grocers are in the vanguard of ventures habituating customers to the remote ordering and delayed delivery of products to the home. Through controlling this “last mile”, online retailers hope to extend the product offer to higher-margin and more problematic products, which are in themselves unprofitable to distribute direct to the customer, but which can be profitably combined with a grocery shop.  相似文献   

Microbial ecology of the stratified water column of the Black Sea as revealed by a comprehensive biomarker study   总被引：2，自引：0，他引：2  

Stuart G. Wakeham  Rudi Amann  Katherine H. Freeman  Ellen C. Hopmans  Bo Barker Jrgensen  Isabell F. Putnam  Stefan Schouten  Jaap S. Sinninghe Damst  Helen M. Talbot  Dagmar Woebken 《Organic Geochemistry》2007,38(12):2070-2097

The stratified water column of the Black Sea is partitioned into oxic, suboxic, and euxinic zones, each characterized by different biogeochemical processes and by distinct microbial communities. In 2003, we collected particulate matter by large volume in situ filtration at the highest resolution to date for lipid biomarker analysis and bacterioplankton for enumeration of major prokaryotic groups. Abundances of several prokaryotic groups were estimated using CARD-FISH probes specific for Bacteria, Archaea (Crenarchaeota and Euryarchaeota), epsilonproteobacteria (mainly sulfide oxidizers) and sulfate reducing bacteria. We also measured a wide range of bacterial and archaeal lipid biomarkers. Depth distributions of diagnostic biomarkers are matched with zonation of microbial processes, including aerobic bacterial oxidation of methane, oxidation of ammonium by bacteria and archaea, metal reduction, and sulfide oxidation at the chemocline, and bacterial sulfate reduction and anaerobic oxidation of methane by archaea in the anoxic zone. Cell densities for archaea and sulfate reducing bacteria are estimated based on water column biomarker concentrations and compared with CARD-FISH results.  相似文献   

Roessingh, Martijn A. Ethnonationalism and Political Systems in Europe: A State of Tension     

Alexander B. Murphy 《GeoJournal》1998,44(1):91-92

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The C/CO ratio in B335 and the decaying dark matter neutrino hypothesis     

Murphy  Little  & Kelly 《Monthly notices of the Royal Astronomical Society》1998,294(4):635-641

C¹⁸O J  = 2–1, C¹⁷O J  = 2–1 and [C  I ] ³P₁–³P₀ emission from the dense cold cloud B335 has been observed and modelled in order to determine the C/CO ratio. The observed ratio is compared with a prediction by Tarafdar who assumes a mechanism in which the CO dissociation is caused by photons of energy ∼ 13.8 eV. These were postulated by Sciama to result from the decay of dark matter neutrinos. Our value for the C/CO ratio sets an upper limit to the strength of the neutrino decay dissociation process, thus providing a significant datum for interstellar chemistry theory.  相似文献   

Pivot poles and plate motion reconstructions     

T.H. Nelson  R.A. Baker  R.W. Murphy 《Tectonophysics》1981,74(1-2)

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An explosion seismology investigation of the continental margin west of the Hebrides, Scotland, at 58°N     

M.H.P. Bott  A.R. Armour  E.M. Himsworth  T. Murphy  G. Wylie 《Tectonophysics》1979,59(1-4)

During summer 1975, a line of large shots was fired across the continental margin between the Rockall Trough and the Hebridean shelf along 58°N. Arrivals were observed at temporary seismic stations set up across Scotland and in northwestern Ireland. A clear P₂ phase was observed to cross the margin and a converted phase P₁ also seen on the records is interpreted as travelling in the sub-sedimentary oceanic crust of Rockall Trough and in the upper continental crust beneath the shelf.The continental crust beneath the Hebridean shelf is estimated to be 27 ± 2 km thick, with P_g = 6.22 ± 0.03 km/s and P_n = 8.01 ± 0.04 km/s as determined by time-term analysis. P_g delays on the outer shelf are interpreted in terms of a seaward thickening wedge of Mesozoic sediments which pre-date the split. P_n beneath the Rockall Trough was poorly determined at 8.20 ± 0.17 km/s and the Moho is estimated to be 18 ± 2 km deep at 58°N. This and other seismic and gravity work indicates a northward thickening of the crust along the Rockall Trough, accounting for the northward decrease in the height of the slope.Our results, and those of gravity interpretations, indicate a relatively abrupt transition between continental and oceanic crust, possibly correlating with the lack of major shelf subsidence. This is attributed to a relatively cool origin for this margin. The main thinning of the continental crust beneath the slope is attributed to outslip of continental crustal material into and beneath the newly forming oceanic crust during the first few million years after the split, possibly enhanced by pre-split stretching.  相似文献