Distribution and source of tar on the Pacific Ocean     

C.S Wong  David R Green  Walter J Cretney 《Marine pollution bulletin》1976,7(6):102-106

Petroleum residues, or tar lumps, are concentrated in the northwestern portion of the Pacific Ocean, particularly in the Kuroshio current system. The source of the tar appears to be tank washings from tankers on the very large Middle East to Japan route. Tar pollutants apparently are discharged by tankers south of Japan, become entrained in the Kuroshio current, and create a plume of contamination which extends downstream for 7000 km across the Pacific.  相似文献   

Reply to comments on “Ray tracing through models of the East African Rift” by W.T.C. Sowerbutts     

A.G. Green 《Earth and Planetary Science Letters》1977,35(3):459-460

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Garnet in silicic liquids and its possible use as a P-T indicator   总被引：1，自引：0，他引：1  

T. H. Green 《Contributions to Mineralogy and Petrology》1977,65(1):59-67

Melting experiments on a model pelitic composition yield low-spessartine garnet as an important residual phase at pressures above 7 kb. The K _D values for distribution of iron and magnesium between coexisting garnet and liquid in the pelitic composition are mainly sensitive to temperature, but also have a small pressure dependence. At temperatures above 950 ° C garnet has a higher value than coexisting liquid, but below 950 ° C the garnet value is lower than that of the coexisting liquid. Thus at temperatures below 950 ° C silicic magmas may fractionate garnet and produce more magnesian derivative liquids.Reconnaissance experiments with added MnO content in the model pelite demonstrate that spessartine-rich garnets are stable in silicic liquids to pressures as low as 3 kb. The MnO and CaO contents of the experimentally crystallized garnets show an antipathetic relation. Also, the grossular content of near-liquidus garnets crystallizing from a range of compositions increases with increasing pressure. The spessartine and grossular contents of most natural garnets in eastern Australian granitic rocks suggest that these garnets formed at pressures greater than 5 kb. Increased spessartine content allows crystallization of garnet in equilibrium with a silicic magma well within the pressure limit of stability of cordierite, provided the garnet contains 10 mol.% spessartine. Thus the depth range over which garnet and cordierite may coexist in a silicic melt is broadened, subject to the availability of MnO. The effect of increased Mn content on the low-pressure stability limit of garnet may also explain the lack of resorption of some garnets in granitic magmas, as these magmas rise to shallower levels. These euhedral garnets characteristically show zoning from an Mn-poor core (typically <4 % MnO) to an Mn-richer rim (typically >4 % MnO) and may reflect continued growth of the garnet in a low pressure regime, stabilized by Mn concentrated in the residual liquid fractions of the crystallizing magma.  相似文献   

Generation of basaltic magma: H. S. Yoder, 1976, National Academy of Sciences Publishing Office,Washington, DC. US$5.50, 265 pp     

D.H. Green 《Geochimica et cosmochimica acta》1977,41(10):1537

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The precise measurement of earth strain     

Ronald Green 《Tectonophysics》1974,23(4):361-371

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Cordierite breakdown under high-pressure,hydrous conditions     

Trevor H. Green  R. H. Vernon 《Contributions to Mineralogy and Petrology》1974,46(3):215-226

Clear evidence exists for a cordierite breakdown reaction to amphibole-kyanite-quartz in high-grade metamorphic rocks of the Arunta Complex, Australia. Using the natural minerals this reaction has been duplicated experimentally. It proceeds over a divariant band with a slope of 12±4 bars/°C, occurring between 8 and 10.4 kb at 750° C and between 9.5 and 11.3 kb at 850°C. The reaction is cut off at low temperature by the appearance of talc and at high temperature by the appearance of orthopyroxene. The maximum pressure stability of the amphibole-kyanite-quartz assemblage is about 20 kb. These data suggest that the natural rock was subjected to pressures of at least 8 kb at 750–850° C for high water fugacities. Other experimental data on the hydration of hypersthene and cordierite-hypersthene stability, point to a temperature below 820° C and an upper pressure limit of 9.5 kb at 750–820°C. Experiments at \(P_{{\text{H}}_{\text{2}} {\text{O}}}\) total indicate that the breakdown of cordierite to amphibole-kyanite-quartz is a hydration reaction, and occurred in the natural rock as a result of an increase of water fugacity at constant total pressure (8–9.5 kb) and temperature (750–820°C).  相似文献   

Talc-garnet-kyanite-quartz schist from an eclogite-bearing terrane,Western Tasmania     

Arne Råheim  D. H. Green 《Contributions to Mineralogy and Petrology》1974,43(3):223-231

Talc-garnet-kyanite-quartz schist occurs in an eclogite-bearing terrane in the Precambrian of Western Tasmania. It is argued that this rock was formed at a pressure of ? 10 kb and a temperature of 600°±20° C. Chemical zoning in the garnet and talc preserves evidence of increasing temperature during growth of the major minerals.  相似文献   

Modelling flow resistance in vegetated streams: review and development of new theory     

Julian C. Green 《水文研究》2005,19(6):1245-1259

Aquatic macrophytes are often the dominant factor influencing flow conditions within the channels they occupy. Existing knowledge of how stream plants affect the flow is outlined, and the different scales at which vegetation resistance operates are proposed. Resistance is shown to be a function of the size of the plants, their structural properties, location in the channel, and the local flow conditions. Current models to calculate this composite resistance effect are assessed in the light of theoretical considerations of the nature of vegetation resistance. New theory is also presented, which demonstrates the non‐linear relationship between channel resistance and the proportion of the channel occupied by vegetation. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Two simple methods for the determination of the resonance frequencies of magnetic field lines     

L.N. Baransky  S.P. Belokris  U.E. Borovkov  C.A. Green 《Planetary and Space Science》1990,38(12):1573-1576

It has previously been shown that application of the “gradient method” to simultaneous recordings of geomagnetic pulsation fields at two stations on a meridian can determine the resonant frequency of a magnetic field line, and that the distribution of resonant frequencies along the meridian can be calculated from three stations. It is shown here that if the D-component spectrum of the pulsations is taken to be a representation of the driving wave, the same information can be derived from one and two station measurements, respectively, albeit with some slight loss of accuracy. It is also suggested that the empirical method of inferring the intensity of the interplanetary magnetic field from the measurement of the period of ground magnetic pulsations would be more accurate if D-component observations only were used.  相似文献   

Emerging coral diseases: a temperature‐driven process?          下载免费PDF全文

Aaron W. Miller  Laurie L. Richardson 《Marine Ecology》2015,36(3):278-291

In the last few decades there has been a surge in research focusing on coral disease. While climate change, specifically rising sea surface temperature, has been proposed as a major and growing driver of the emergence of marine diseases, to date a solid connection between disease epizootics and elevated sea surface temperature has not been established. However, a wealth of data now exists, compiled from many different perspectives, that may support such a connection. In this work we provide a comprehensive review targeting one coral disease, black band disease, that spans the infection process, pathobiology, and epizootiology, and links specific mechanisms of the disease process to increasing temperatures. This temperature‐driven pattern of infection can be expanded to include similar processes associated with other temperature‐related coral diseases. The conclusions presented here are based upon the results of many studies using a diverse suite of approaches that have been synthesized to argue that the emergence and continuing spread of black band disease is linked to warming sea surface temperatures. In summary, as global ocean temperatures increase seasonally and over decades, the environment shifts to become more favorable for the growth of potentially pathogenic microorganisms endemic to the immediate environment of the reef. The increase in the relative number of potential pathogens in the microbial community produces microenvironments conducive to the growth of other potential pathogens, leading to infection by a polymicrobial consortium. This consortium is easily perturbed by a (seasonal) temperature decrease, but remains associated with the coral host and can be reactivated with a subsequent seasonal increase in temperature, resulting in a cycle of temperature‐dependent disease emergence.  相似文献