Actually achieving marine sustainability demands a radical re-think in approach, not 'more of the same'     

Morris D  O'Brien C  Larcombe P 《Marine pollution bulletin》2011,62(5):1053-1057

The UK is committed to meeting a series of ‘high-level marine objectives’ which are required to satisfy national obligations and to meet international commitments for the marine environment. There are more than 16 such international high-level policy driven obligations and commitments, together with more than 18 European and more than 12 of national origin. In the UK, there is an assumption that the current and planned monitoring will provide evidence to demonstrate achievement against these high-level objectives.  相似文献   

Mineralogical, petrological, and petrogenetic analysis of felsic intrusive rocks at the Sisson Brook W-Mo-Cu deposit, west-central New Brunswick     

ZHANG Wei  Christopher R.M. MCFARLANE  Dave LENTZ 《《地质学报》英文版》2013,87(Z1):831-834

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TAOS – The Taiwanese‐American Occultation Survey     

M. J. Lehner  C. Alcock  T. Axelrod  F. Bianco  Y.‐I. Byun  W.‐P. Chen  K. H. Cook  R. Dave  I. de Pater  J. Giammarco  S.‐K. King  T. Lee  J. Lissauer  S. L. Marshall  S. Mondal  T. Nihei  J. Rice  M. Schwamb  A. Wang  S.‐Y. Wang  C.‐Y. Wen  Z.‐W. Zhang 《Astronomische Nachrichten》2006,327(8):814-817

The Taiwanese‐American Occultation Survey (TAOS) seeks to determine the number and size spectrum for small (∼3 km) bodies in the Kuiper Belt. This will be accomplished by searching for the brief occultations of bright stars (R ∼ 14) by these objects. We have designed and built a special purpose photometric monitoring system for this purpose. TAOS comprises four 50 cm telescopes, each equipped with a 2048 × 2048 pixel CCD camera, in a compact array located in the central highlands of Taiwan. TAOS will monitor up to 2 000 stars at 5 Hz. The system went into scientific operation in the autumn of 2005. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

The ability of detainment bunds to decrease sediments transported from pastoral catchments in surface runoff     

Brian Levine  Lucy Burkitt  Dave Horne  Chris Tanner  James Sukias  Leo Condron  John Paterson 《水文研究》2021,35(8):e14309

Erosion leading to sedimentation in surface water may disrupt aquatic habitats and deliver sediment-bound nutrients that contribute to eutrophication. Land use changes causing loss of native vegetation have accelerated already naturally high erosion rates in New Zealand and increased sedimentation in streams and lakes. Sediment-bound phosphorus (P) makes up 71–79% of the 17–19 t P y⁻¹ delivered from anthropogenic sources to Lake Rotorua in New Zealand. Detainment bunds (DBs) were first implemented in the Lake Rotorua catchment in 2010 as a strategy to address P losses from pastoral agriculture. The bunds are 1.5–2 m high earthen stormwater retention structures constructed across the flow path of targeted low-order ephemeral streams with the purpose of temporarily ponding runoff on productive pastures. The current DB design protocol recommends a minimum pond volume of 120 m³ ha⁻¹ of contributing catchment with a maximum pond storage capacity of 10 000 m³. No previous study has investigated the ability of DBs to decrease annual suspended sediment (SS) loads leaving pastoral catchments. Annual SS yields delivered to two DBs with 20 ha and 55 ha catchments were 109 and 28 kg SS ha⁻¹, respectively, during this 12-month study. The DBs retained 1280 kg (59%) and 789 kg (51%) of annual SS loads delivered from the catchments as a result of the bunds' ability to impede stormflow and facilitate soil infiltration and sediment deposition. The results of this study highlight the ability of DBs to decrease SS loads transported from pastures in surface runoff, even during large storm events, and suggests DBs are able to reduce P loading in Lake Rotorua.  相似文献   

gLucifer: next generation visualization framework for high-performance computational geodynamics     

Dave R. Stegman  Louis Moresi  Robert Turnbull  Julian Giordani  Patrick Sunter  Alan Lo  Steve Quenette 《Visual Geosciences》2008,13(1):71-84

High-performance computing provides unprecedented capabilities to produce higher resolution 4-D models in a fraction of time. Thus, the need exists for a new generation of visualization systems able to maintain parity with the enormous volume of data generated. In attempting to write this much data to disk, each computational step introduces a significant performance bottleneck, yet most existing visualization software packages inherently rely on reading data in from a dump file. Available packages make this assumption of postprocessing at quite a fundamental level and are not very well suited for plotting very large numbers of specialized particles. This necessitates the creation of a new visualization system that meets the needs of large-scale geodynamic modeling. We have developed such a system, gLucifer, using a software framework approach that allows efficient reuse of our efforts in other areas of research. gLucifer is capable of producing movies of a 4-D data set “on the fly” (simultaneously with running the parallel scientific application) without creating a performance bottleneck. By eliminating most of the human efforts involved in visualizing results through postprocessing, gLucifer reconnects the scientist to the numerical experiment as it unfolds. Data sets that were previously very difficult to even manage may be efficiently explored and interrogated without writing to disk, and because this approach is based entirely on memory distributed across as many processors as are being utilized by the scientific application, the visualization solution is scalable into terabytes of data being rendered in real time.  相似文献   

Interactive visualization of 3D mantle convection     

Megan Damon  Masanori C. Kameyama  Michael Knox  David H. Porter  Dave Yuen  Erik O. D. Sevre 《Visual Geosciences》2008,13(1):49-57

The current availability of thousands of processors at many high performance computing centers has made it feasible to carry out, in near real time, interactive visualization of 3D mantle convection temperature fields, using grid configurations having 10–100 million unknowns. We will describe the technical details involved in carrying out this endeavor, using the facilities available at the Laboratory of Computational Science and Engineering (LCSE) at the University of Minnesota. These technical details involve the modification of a parallel mantle convection program, ACuTEMan; the usage of client–server socket based programs to transfer upwards of a terabyte of time series scientific model data using a local network; a rendering system containing multiple nodes; a high resolution PowerWall display, and the interactive visualization software, DSCVR. We have found that working in an interactive visualizastion mode allows for fast and efficient analysis of mantle convection results. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Increasing the usability and accessibility of geodynamic modelling tools to the geoscience community: UnderworldGUI     

Shea Goyette  Masa Takatsuka  Stuart Clark  R. Dietmar Müller  Patrice Rey  Dave R. Stegman 《Visual Geosciences》2008,13(1):25-36

Geoscientists are faced with a number of complexities that represent obstacles to the development of realistic simulation of deep earth processes. Realistic 4D thermo-mechanical simulation using software packages like Underworld and Gale, when combined appropriately with geoscientific expertise, can lead to novel insights into the deformation of geological structures at a wide range of time and spatial scales. The challenge for end-user geoscientists lies in applying their knowledge within the framework of the software’s input specification, including initial, internal, and boundary conditions and output visualization parameters. We have built a Graphical User Interface (GUI) to remove many of the difficulties related to editing the Extensible Markup Language (XML) encoded input files of Underworld/Gale geomodels and therefore, to greatly broaden the user base of these software packages. By helping Underworld/Gale to meet a large audience, we provide a tool to the geoscience community that helps to move from untested conceptual models to physically valid, properly scaled modelling. Furthermore, the UnderworldGUI offers a mechanism for storing and retrieving experimental models in a centralised database, thus providing the geoscience community with a means to share the outcomes of its experimental research. Further details of the UnderworldGUI are available at the web site .

Shea GoyetteEmail:

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Diamondiferous peridotitic microxenoliths from the Diavik Diamond Mine, NT     

Steven Creighton  Thomas Stachel  Hayley McLean  Karlis Muehlenbachs  Antonio Simonetti  Dave Eichenberg  Robert Luth 《Contributions to Mineralogy and Petrology》2008,155(5):541-554

Twenty-five diamonds recovered from 21 diamondiferous peridotitic micro-xenoliths from the A154 South and North kimberlite pipes at Diavik (Slave Craton) match the general peridotitic diamond production at this mine with respect to colour, carbon isotopic composition, and nitrogen concentrations and aggregation states. Based on garnet compositions, the majority of the diamondiferous microxenoliths is lherzolitic (G9) in paragenesis, in stark contrast to a predominantly harzburgitic (G10) inclusion paragenesis for the general diamond production. For garnet inclusions in diamonds from A154 South, the lherzolitic paragenesis, compared to the harzburgitic paragenesis, is distinctly lower in Cr content. For microxenolith garnets, however, Cr contents for garnets of both the parageneses are similar and match those of the harzburgitic inclusion garnets. Assuming that the microxenolith diamonds reflect a sample of the general diamond population, the abundant Cr-rich lherzolitic garnets formed via metasomatic overprinting of original harzburgitic diamond sources subsequent to diamond formation, conversion of original harzburgitic diamond sources occurred in the course of metasomatic overprint re-fertilization. Metasomatic overprinting after diamond formation is supported by the finding of a highly magnesian olivine inclusion (Fo₉₅) in a microxenolith diamond that clearly formed in a much more depleted environment than indicated by the composition of its microxenolith host. Chondrite normalized REE patterns of microxenolith garnets are predominantly sinusoidal, similar to observations for inclusion garnets. Sinusoidal REE_N patterns are interpreted to indicate a relatively mild metasomatic overprint through a highly fractionated (very high LREE/HREE) fluid. The predominance of such patterns may explain why the proposed metasomatic conversion of harzburgite to lherzolite appears to have had no destructive effect on diamond content. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Mineralogical controls on environmental mobility of arsenic from historic mine processing residues,New Zealand     

Laura Haffert  Dave Craw 《Applied Geochemistry》2008

Processing of arsenopyrite ore took place at Blackwater Au mine, New Zealand, between 1908 and 1951 and no rehabilitation was undertaken after mine closure. High As concentrations in solid processing residues (up to 40 wt% As) are due to secondary As minerals. Site pH regimes vary from 4.1 to circum-neutral. Originally, all processed As was present as arsenolite (arsenic trioxide polymorph, As^III), a by-product of arsenopyrite roasting. Near the roaster, scorodite precipitated as a result of the high dissolved As concentration during arsenolite dissolution. The formation of scorodite has two major consequences. Firstly, the scorodite precipitate cements the ground in the vicinity of the roaster area, thereby creating an impermeable surface crust (up to 30 wt% As) and encapsulating weathered arsenolite grains within the cement. Secondly, formation of scorodite temporarily immobilizes some of the dissolved As that is generated during nearby arsenolite dissolution. Where all the available arsenolite has dissolved, scorodite becomes soluble, and the dissolved As concentrations are controlled by scorodite solubility, which is at least two orders of magnitudes lower than arsenolite solubility. Downstream Eh conditions fall below the As^V/As^III boundary, so that scorodite does not precipitate and dissolved As concentrations are controlled by arsenolite solubility. Dissolved As reaches up to 52 mg/L in places, and exceeds the current WHO drinking water guideline of 0.01 mg/L by 5200 times. This study shows that dissolved As concentrations in discharge waters at historic mine sites are dependent on the processing technology and associated mineralogy.  相似文献   

Regional magma plumbing and emplacement mechanisms of the Faroe‐Shetland Sill Complex: implications for magma transport and petroleum systems within sedimentary basins          下载免费PDF全文

Nick Schofield  Simon Holford  John Millett  David Brown  David Jolley  Simon R. Passey  Dave Muirhead  Clayton Grove  Craig Magee  Joanne Murray  Malcolm Hole  Christopher A.‐L. Jackson  Carl Stevenson 《Basin Research》2017,29(1):41-63

The movement of magma through the shallow crust and the impact of subsurface sill complexes on the hydrocarbon systems of prospective sedimentary basins has long been an area of interest and debate. Based on 3D seismic reflection and well data, we present a regional analysis of the emplacement and magmatic plumbing system of the Palaeogene Faroe‐Shetland Sill Complex (FSSC), which is intruded into the Mesozoic and Cenozoic sequences of the Faroe‐Shetland Basin (FSB). Identification of magma flow directions through detailed seismic interpretation of approximately 100 sills indicates that the main magma input zones into the FSB were controlled primarily by the NE–SW basin structure that compartmentalise the FSB into its constituent sub‐basins. An analysis of well data shows that potentially up to 88% of sills in the FSSC are <40 m in thickness, and thus below the vertical resolution limit of seismic data at depths at which most sills occur. This resolution limitation suggests that caution needs to be exercised when interpreting magmatic systems from seismic data alone, as a large amount of intrusive material could potentially be missed. The interaction of the FSSC with the petroleum systems of the FSB is not well understood. Given the close association between the FSSC and potential petroleum migration routes into some of the oil/gas fields (e.g. Tormore), the role the intrusions may have played in compartmentalisation of basin fill needs to be taken fully into account to further unlock the future petroleum potential of the FSB.  相似文献