Reactive flow models of the Anarraaq Zn–Pb–Ag deposit,Red Dog district,Alaska     

Christian Schardt  Grant Garven  Karen D. Kelley  David L. Leach 《Mineralium Deposita》2008,43(7):735-757

The Red Dog ore deposit district in the Brooks Range of northern Alaska is host to several high-grade, shale-hosted Zn + Pb deposits. Due to the complex history and deformation of these ore deposits, the geological and hydrological conditions at the time of formation are poorly understood. Using geological observations and fluid inclusion data as constraints, numerical heat and fluid flow simulations of the Anarraaq ore deposit environment and coupled reactive flow simulations of a section of the ore body were conducted to gain more insight into the conditions of ore body formation. Results suggest that the ore body and associated base metal zonation may have formed by the mixing of oxidized, saline, metal-bearing hydrothermal fluids (<200°C) with reducing, HS-rich pore fluids within radiolarite-rich host rocks. Sphalerite and galena concentrations and base metal sulfide distribution are primarily controlled by the nature of the pore fluids, i.e., the extent and duration of the HS⁻ source. Forward modeling results also predict the distribution of pyrite and quartz in agreement with field observations and indicate a reaction front moving from the initial mixing interface into the radiolarite rocks. Heuristic mass calculations suggest that ore grades and base metal accumulation comparable to those found in the field (18% Zn, 5% Pb) are predicted to be reached after about 0.3 My for initial conditions (30 ppm Zn, 3 ppm Pb; 20% deposition efficiency).  相似文献   

Information infrastructure for Australia’s Integrated Marine Observing System     

Marton G. Hidas  Roger Proctor  Natalia Atkins  Julian Atkinson  Laurent Besnard  Peter Blain  Philip Bohm  Jon Burgess  Kim Finney  Dan Fruehauf  Guillaume Galibert  Xavier Hoenner  Jacqui Hope  Craig Jones  Sebastien Mancini  Benedicte Pasquer  David Nahodil  Kate Reid  Katherine Tattersall 《Earth Science Informatics》2016,9(4):525-534

Australia’s Integrated Marine Observing System (IMOS, imos.org.au) is research infrastructure to establish an enduring observing program for Australian oceanic waters and shelf seas. The observations cover physical, biological, and chemical variables to address themes of multi-decadal ocean change, climate variability and weather extremes, boundary currents and inter-basin flows, continental shelf processes and ecosystem responses.IMOS observations are collected by national facilities based on various platform types and operated by partner institutions around the country. In this paper we describe the infrastructure and workflows developed to manage and distribute the data to the public. We highlight the existing standards and open-source software we have adopted, and the contributions we have made. To demonstrate the value of this infrastructure we provide some illustrations of use and uptake.All IMOS data are freely and openly available to the public via the Ocean Portal (https://imos.aodn.org.au). All IMOS-developed software is open-source and accessible at https://github.com/aodn.  相似文献   

数据稀缺生态系统中多种类质量谱模型的构建   总被引：1，自引：0，他引：1  

张崇良  陈勇  THOMPSON Katherine  任一平 《海洋学报(英文版)》2016,35(4):63-73

多种类生态模型已经被广泛应用于渔业活动影响应预测和管理措施效果评估。质量谱模型是一种基于生理过程构建的生态模型,该模型为描述鱼类群落在个体摄食变异和随个体发生的生态位迁移提供了一个可行的方法。尽管生态模型在增进生态系统认识上具有重要意义,其应用在数据稀缺的渔业中受到很大限制。作为实践基于生态系统渔业管理(EBFM)的第一步,本研究构建了海州湾鱼类群落的质量谱模型。本研究详述了数据收集和模型参数化的过程,以促进该模型在数据稀缺的生态系统中未来的应用。作为一个范例,研究展示了不同捕捞努力量对生态系统的影响,并采用一套生态指标监测其动态。群落生物量、多样性指数、W指数,大鱼指数(LFI),平均体重和群落质量谱斜率对捕捞压力的响应呈非线性,最大的捕捞强度并非总是对鱼类群落产生最强的影响。本文强调了构建谱模型在生态研究中的的价值和可行性,并讨论了模型的局限性和改进的可能。本研究旨在促进质量谱模型的广泛应用以更好地支持基于生态系统的渔业管理。  相似文献   

Implications of uncertain future fossil energy resources on bioenergy use and terrestrial carbon emissions     

Katherine?CalvinEmail author  Marshall?Wise  Patrick?Luckow  Page?Kyle  Leon?Clarke  Jae?Edmonds 《Climatic change》2016,136(1):57-68

The magnitude and character of the global resource base of fossil fuels is a key determinant of the evolution of the future global energy system and corresponding fossil fuel carbon emissions. What is less well understood is the potential magnitude of impact of the availability of fossil fuels, due to the interaction with biomass energy, on agriculture, land use, ecosystems and therefore carbon emissions from land-use change. This paper explores these links and implications. We show that if oil resources are limited, then the consequently higher price for liquids induces both the use of coal-to-liquids technology deployment, but also enhanced production of bioenergy crops particularly in a business-as-usual scenario. This in turn implies greater pressure to convert unmanaged ecosystems to produce bioenergy, and higher rates of terrestrial carbon emissions from land use.  相似文献   

Ichthyoplankton distribution and abundance in the Celtic Sea   总被引：1，自引：1，他引：1  

Horstman  Katherine R.; Fives  Julie M. 《ICES Journal of Marine Science》1994,51(4):447-460

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The effects of storms and storm-generated currents on sand beaches in Southern Maine, USA   总被引：2，自引：0，他引：2  

Heather W. Hill  Joseph T. Kelley  Daniel F. Belknap  Stephen M. Dickson   《Marine Geology》2004,210(1-4):149-168

Storms are one of the most important controls on the cycle of erosion and accretion on beaches. Current meters placed in shoreface locations of Saco Bay and Wells Embayment, ME, recorded bottom currents during the winter months of 2000 and 2001, while teams of volunteers profiled the topography of nearby beaches. Coupling offshore meteorological and beach profile data made it possible to determine the response of nine beaches in southern Maine to various oceanographic and meteorological conditions. The beaches selected for profiling ranged from pristine to completely developed and permitted further examination of the role of seawalls on the response of beaches to storms.

Current meters documented three unique types of storms: frontal passages, southwest storms, and northeast storms. In general, the current meter results indicate that frontal passages and southwest storms were responsible for bringing sediment towards the shore, while northeast storms resulted in a net movement of sediment away from the beach. During the 1999–2000 winter, there were a greater percentage of frontal passages and southwest storms, while during the 2000–2001 winter, there were more northeast storms. The sediment that was transported landward during the 1999–2000 winter was reworked into the berm along moderately and highly developed beaches during the next summer.

A northeast storm on March 5–6, 2001, resulted in currents in excess of 1 m s⁻¹ and wave heights that reached six meters. The storm persisted over 10 high tides and caused coastal flooding and property damage. Topographic profiles made before and after the storm demonstrate that developed beaches experienced a loss of sediment volume during the storm, while sediment was redistributed along the profile on moderately developed and undeveloped beaches. Two months after the storm, the profiles along the developed beaches had not reached their pre-storm elevation. In comparison, the moderately developed and undeveloped beaches reached and exceeded their pre-storm elevation and began to show berm buildup characteristic of the summer months.  相似文献   

Hindcast of the Argo merchant spill using the uri oil spill fates model     

Malcolm L. Spaulding  Katherine B. Jayko  Eric L. Anderson 《Ocean Engineering》1982,9(5):455-482

A comprehensive oilspill fates model, developed by Cornillon and Spaulding at the University of Rhode Island, has been employed to hindcast the well-studied Argo Merchant spill. Using data collected during the spill to define the environmental conditions and the oil composition, properties and release rates, the oil spill fates model was used to predict the spatial and temporal distribution of spilled oil from December 16 to 31, 1976. Comparison of model predictions to observations for spilled oil mass balance, surface trajectories and oiled surface area was in general quite good. Improved predictions require a better definition of the wind and tidally-forced circulation in the vicinity of the wreck site, a more soundly based theory for oil entrainment or dispersion into the water column and an oil spreading theory which more accurately addresses the complex behaviour of a weathering multicomponent petroleum hydrocarbon.  相似文献   

The diffusive regime of double-diffusive convection   总被引：2，自引：0，他引：2  

D. E. Kelley  H. J. S. Fernando  A. E. Gargett  J. Tanny  E. zsoy 《Progress in Oceanography》2003,56(3-4):461

The diffusive regime of double-diffusive convection is discussed, with a particular focus on unresolved issues that are holding up the development of large-scale parameterizations. Some of these issues, such as interfacial transports and layer-interface interactions, may be studied in isolation. Laboratory work should help with these. However, we must also face more difficult matters that relate to oceanic phenomena that are not represented easily in the laboratory. These lie beneath some fundamental questions about how double-diffusive structures are formed in the ocean, and how they evolve in the competitive ocean environment.  相似文献   

A Geographic Analysis of Drug Trafficking Patterns on the TOR Network          下载免费PDF全文

Diana S. Dolliver  Steven P. Ericson  Katherine L. Love 《Geographical review》2018,108(1):45-68

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Rhizocarpon calibration curve for the Aoraki/Mount Cook area of New Zealand     

Thomas V. Lowell  Katherine Schoenenberger  James A. Deddens  George H. Denton  Colby Smith  Jessica Black  Chris H. Hendy 《第四纪科学杂志》2005,20(4):313-325

Development of Rhizocarpon growth curve from the Aoraki/Mount Cook area of New Zealand provides a means to assess Little Ice Age glacier behaviour and suggests approaches that have wider application. Employing a sampling strategy based on large populations affords the opportunity to assess which of various metrics (e.g. single largest, average of five largest, mean of an entire population) best characterise Rhizocarpon growth patterns. The 98% quantile from each population fitted with a quadric curve forms a reliable representation of the growth pattern. Since this metric does not depend on the original sample size, comparisons are valid where sample strategy must be adapted to local situations or where the original sample size differs. For the Aoraki/Mount Cook area a surface 100 years old will have a 98% quantile lichen diameter of 34.3 mm, whereas a 200‐year‐old surface will have a lichen diameter of 73.7 mm. In the Southern Alps, constraints from the age range of calibration points, the flattening of the quadric calibration curve and ecological factors limit the useful age range to approximately 250 years. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献