Maximum horizontal stress orientations in the Cooper Basin, Australia: implications for plate-scale tectonics and local stress sources     

Scott D. Reynolds  Scott D. Mildren  Richard R. Hillis  Jeremy J. Meyer  Thomas Flottmann 《Geophysical Journal International》2005,160(1):332-344

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High resolution provenancing of long travelled dust deposited on the Southern Alps, New Zealand     

Hamish A. McGowan  Balz Kamber  Grant H. McTainsh  Samuel K. Marx 《Geomorphology》2005,69(1-4):208-221

On 7 February 2000 an atypical orange discolouration of snowfields in the central Southern Alps, New Zealand occurred following the passage of a cold front. Analysis of snow samples identified fine orangey-brown dust mixed with much coarser grey dust. Air parcel forward trajectories from dust sources in southern and central Australia, where dust storms were reported on 4 February 2000, were computed to identify the deposits source. Geochemical analyses of the dust deposit using 26 trace elements, unaffected by regional air pollution and gravitational sorting, indicate that 20% of the dust was sourced from western New South Wales, with 45% from the eastern Eyre Peninsula of South Australia and the remaining 35% was local New Zealand dust. This provenancing approach provides a spatial resolution of long travelled dust sourcing not previously achieved.  相似文献   

Modulation of the Solar Magnetic Cycle     

De Meyer  F. 《Solar physics》1998,181(1):201-219

The modulation model of the solar magnetic cycle for the time interval from 1650 to 1996 A.D. describes an harmonic oscillator with a basic (22.13 ± 0.05)-yr period, which is subjected to amplitude and phase variations that can be represented by a sum of trigonometric series. The simulated sunspot data explain 97.9% of cycle peak height variance and the residual standard deviation is 8.6 mean annual sunspots. A peak height of 139 for cycle 23 occurring in 2001 is predicted, whereas cycle 24 would have a maximum around 132 in 2014. Simulation of the sunspot numbers from 1000 until 2400 A.D. shows that the model recreates recurring minima (Maunder and Spörer Minimum). The prediction also expects a high level of amplitude modulation in the interval 1950–2010 with a rapid decrease afterwards. A greatly reduced cycle activity is reproduced by the simulation from about 2065 to 2100 A.D. No direct explanation of the long-term periodicities of the model can be advanced. The high-frequency contribution of the phase modulation, which accounts for the skewness of the solar cycle, shows coincidences with the orbital periods of Jupiter and Saturn, but no physical basis for the matching periodicities can be conceived.  相似文献   

Contaminants in sediments: Using robust regression for grain-size normalization     

Alastair Grant  Richard Middleton 《Estuaries and Coasts》1998,21(2):197-203

Sediment contaminant concentrations usually show an inverse correlation with grain size. This can cause difficulties in distinguishing real differences in contamination from artifacts caused by variations in sediment texture. To overcome this, regression analysis is frequently used to remove the dependency of concentrations on grain size. However, least squares regression lines can be affected markedly by the presence of a small number of unusual samples in the dataset. These outliers may represent samples which are more severely contaminated or which were derived from areas with different underlying geology. They can be removed semi-manually, but robust regression methods such as least absolute values provide a convenient and objective alternative. The methods are illustrated using an example dataset of metal contaminants in sediments from the Humber Estuary, United Kingdom. Least squares regression on the complete dataset yields a rather poor grain size normalization for several elements. By contrast, least absolute values regression produces results very similar to those obtained by least squares regression after careful manual removal of outliers, but it avoids the need for subjective judgments of which data points to omit from the analysis. The intercepts of several of the fitted regression lines were non-zero, indicating that regression-based normalization is preferable to methods based on ratios.  相似文献   

The magnetotelluric phase tensor   总被引：31，自引：0，他引：31  

T. Grant Caldwell  Hugh M. Bibby  Colin Brown 《Geophysical Journal International》2004,158(2):457-469

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Do Pharmaceuticals, Pathogens, and Other Organic Waste Water Compounds Persist When Waste Water Is Used for Recharge?   总被引：3，自引：0，他引：3  

Gail E. Cordy  Norma L. Duran  Herman Bouwer  Robert C. Rice  Edward T. Furlong  Steven D. Zaugg  Michael T. Meyer  Larry B. Barber  Dana W. Kolpin 《Ground Water Monitoring & Remediation》2004,24(2):58-69

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Modelling Carbon Dynamics of Boreal Forest Ecosystems Using the Canadian Land Surface Scheme   总被引：1，自引：1，他引：1  

Shusen Wang  Robert F. Grant  Diana L. Verseghy  T. Andrew Black 《Climatic change》2002,55(4):451-477

The ecosystem carbon (C) and nitrogen (N) simulations recently implemented in the Canadian Land Surface Scheme (CLASS) are presented. The main calculations include plant photosynthesis, autotrophic respiration, root N uptake, litterfall, plant growth, and soil heterotrophic respiration. Model experiments are made on two boreal forest ecosystems, deciduous (aspen) and conifers (black spruce). Simulated plant, soil, and ecosystem CO₂ exchanges are analysed on half-hourly, daily, and annual time scales and compared with tower eddy correlation flux measurements and estimates from various authors. Modeled daily ecosystem CO₂ exchange explained86% and 54%, respectively, of the observed variance of eddy correlationflux at the aspen site and at the black spruce site. Annual results show that the aspen ecosystem was simulated as a C sink in both 1994 (+164 g Cm^–2) and 1996 (+142 g C m^–2), and the black spruce ecosystem wassimulated as a C sink in 1994 (+39 g C m^–2) and 1995 (+25 g Cm^–2), but as a C source in 1996 (–27 g C m^–2).  相似文献   

Why Indoor Climates Change: A Case Study     

William B. Meyer 《Climatic change》2002,55(3):395-407

Indoor climates and climate change are an integral – but to date poorly integrated – element of climate and climate-change research more generally. They have been examined chiefly through the study of human thermal comfort, about which two conflicting schools of thought have emerged. One sees thermal comfort as governed by a common and fixed human preference and confined to a narrow range of conditions. The other sees it as strongly influenced by habit and expectations, which can differ greatly from one person, place, or period to another. This paper examines, in the light of these theories and what they imply, an episode of major and rapid indoor climate change – a sharp rise in winter temperatures thatoccurred in the northern United States in the first half of the nineteenth century. It finds support for both points of view and suggests that each is valid under particular circumstances. The results, if borne out by more research, will help to inform projections of future demand for heating and cooling and for outdoor climatic amenities, both significant elements of the human dimensions of global climatic change.  相似文献   

The clay-with-flints of the western Paris Basin: a potential aggregate resource     

Benoit Laignel  Christopher H. Spencer  Robert Meyer 《Environmental Geology》2002,41(5):525-536

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Desiccation tolerance ofEurypanopeus depressus (smith) (Decapoda: Xanthidae) and the exploitation of microhabitat     

Jonathan Grant  Jack McDonald 《Estuaries and Coasts》1979,2(3):172-177

Investigations into zonation of estuarine invertebrates often indicate that animals living higher in the intertidal region have greater tolerance to effects of aerial exposure. Desiccation tolerances ofEurypanopeus depressus, a xanthid mud crab, were measured in the laboratory for both intertidal and subtidal populations to determine whether intertidal distribution is the result of either increased physiological resistance to drying or other factors. Initially, both populations had a similar percentage of body weight due to water, and at time of death both had lost a similar percentage of water. Desiccation tolerance increased exponentially with size. In laboratory experiments,E. depressus appears very susceptible to desiccation stress with loss of tactile response occurring at 30% depletion of body water. This crab may be able to avoid desiccation and survive in the intertidal zone by remaining in the shelter and moisture of oyster shells and mud at low tide. However,E. depressus may not be limited strictly by physical factors of its environment. Biotic factors such as behavior leading to predator avoidance are possibly more important components in limiting distribution.  相似文献