Autoregressive estimation of complex eigenfrequencies in low frequency seismic spectra   总被引：5，自引：0，他引：5  

B. Feng Chao  Freeman Gilbert 《Geophysical Journal International》1980,63(3):641-657

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The fact that a seismogram can be represented as an autoregressive (AR) time series and the use of Prony's method enable us to obtain the complex frequencies from the poles of the corresponding AR process. A frequency-domain formulation which employs a time-domain tapering technique is devised so that spectral peaks can be analysed individually, or in small groups. Statistical analysis of the estimators and several examples from two recent earthquakes illustrate the method.  相似文献   

Elastic waves in a transitional solid with arbitrarily small rigidity     

Freeman Gilbert 《Geophysical Journal International》1998,133(2):230-232

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Environmental Impact Statements     

Gilbert F. White 《The Professional geographer》1972,24(4):302-309

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Geography And Public Policy1     

Gilbert F. White 《The Professional geographer》1972,24(2):101-101

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Social acceptability of a marine protected area: The case of Reunion Island     

Aurélie Thomassin  Carole S. White  Selina S. Stead  Gilbert David 《Ocean & Coastal Management》2010,53(4):169-179

This paper examines variations in social acceptability of a Marine Protected Area (MPA) prior to implementation. The influence of a number of factors, including socio-economic characteristics, perception of coral resources state of health and attitudes towards non-compliance with regulations are analysed. During May 2006, 640 questionnaires were distributed to school children around Reunion Island, Western Indian Ocean, for completion by their parents, following an informal educational activity made in school. From a 73% (n = 469) response rate, results showed that 78% of participants were in favour of the MPA. Analysis further identified that those supportive of the MPA were generally from higher socio-professional categories, had a negative perception of the coral reef ecosystem's health and were not originally from Reunion. In contrast, locals (born in Reunion) from lower socio-professional categories or with no employment activity and having a positive perception of the health status of coral reefs offered no opinion on the MPA. Attitudes towards enforcement and compliance highlighted that SCUBA divers, fishers and jet skiers attributed a higher value to the protection of the coral reef environment through enforcement of MPA regulations than to their own use of the coral reef resource. When asked about the use of penalties to deter non-compliance, swimmers were awarded the lowest fines, followed by SCUBA divers, fishers then jet skiers being awarded the highest fines. Thus, the more severe the act of non-compliance by a resource user group was perceived to be, the more these users themselves disapproved of non-compliant behaviour and supported use of high penalties. The survey design through focusing on school children's parents, demonstrated a simple and cost-effective method for data collection while providing environmental education, which could be employed in similar case studies elsewhere.  相似文献   

Preface: The interacting scales of ocean dynamics – A tribute to Chris Garrett     

Denis Gilbert Convenor  Patrick Cummins Convenor 《大气与海洋》2013,51(4):1-2

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Multivariate Analysis of an LA-ICP-MS Trace Element Dataset for Pyrite   总被引：2，自引：0，他引：2  

Lyron Winderbaum  Cristiana L. Ciobanu  Nigel J. Cook  Matthew Paul  Andrew Metcalfe  Sarah Gilbert 《Mathematical Geosciences》2012,44(7):823-842

Application of multivariate statistics to trace element datasets is reviewed using 164 multi-element LA-ICP-MS spot analyses of pyrite from the Moonlight epithermal gold prospect, Queensland, Australia. Multivariate analysis of variance (MANOVA) is used to demonstrate that classification of pyrite on morphological and other non-numeric factors is geochemically valid. Parallel coordinate plots and correlation cluster analysis using Spearman??s coefficients are used to discover unexpected elemental relationships without making assumptions a priori. Finally, principal component analysis and factor analysis are used to demonstrate the presence of sub-classes of pyrite. Corroborated with geological data, statistical analysis provides evidence for successive generations of hydrothermal fluids, each introducing specific metals, and for partial or complete replacement of different minerals. The data permit reinterpretation of Moonlight as a telescoped system where epithermal-Au (± base metals) is superposed onto early porphyry-Mo mineralization.  相似文献   

Reedbed evapotranspiration rates in England     

P. M. Fermor  P. D. Hedges  J. C. Gilbert  D. J. G. Gowing 《水文研究》2001,15(4):621-631

Measurements of evapotranspiration from contrasting stands of Phragmites australis [ET(Reed)] were obtained over several years at three sites within England between 1994 and 1998. A comparison with published ET(Reed) values showed the UK rates to be considerably lower than those measured in continental Europe. From the ET(Reed) data monthly crop coefficients [K_c(Reed)] have been developed, which when used with Reference Crop Evapotranspiration will enable reedbed water use to be determined. Due to the differences in study site characteristics, values for K_c varied widely, and it was not considered appropriate to combine results to produce a single set of monthly mean values. However, suggestions are made regarding the application of the K_c(Reed) values to wetland design. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

The Sunyaev–Zeldovich background     

Gilbert P. Holder †  Ian G. McCarthy  A. Babul 《Monthly notices of the Royal Astronomical Society》2007,382(4):1697-1706

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Minor and trace elements in bornite and associated Cu-(Fe)-sulfides: A LA-ICP-MS studyBornite mineral chemistry   总被引：1，自引：0，他引：1  

Nigel J. Cook  Cristiana L. Ciobanu  Sarah Gilbert 《Geochimica et cosmochimica acta》2011,75(21):6473-6496

In situ laser ablation inductively-coupled mass spectroscopy (LA-ICP-MS) has been used to provide a baseline dataset on the minor element contents in hypogene bornite and accompanying Cu-sulfides from 12 deposits with emphasis on syn-metamorphic Cu-vein systems in Norway, and skarn, porphyry and epithermal systems in SE Europe.Bornite contains significant concentrations of both Ag and Bi, especially in the vein and skarn deposits studied and has the potential to be a major Ag-carrier in such ores. Concentrations of up to >1 wt.% of both elements are documented. Measured concentrations appear to be independent of whether discrete Ag- and/or Bi-minerals are present within the analyzed sulfide. Where bornite and chalcocite (or mixtures of Cu-sulfides) coexist, Ag is preferentially partitioned into chalcocite over co-existing bornite and Bi is partitioned into the bornite. Bornite is a relatively poor host for Au, which mimics Ag by being typically richer in coexisting chalcocite. Most anomalous Au concentrations in bornite can be readily tracked to micron- and submicron-scale inclusions, but bornite and chalcocite containing up to 3 and 28 ppm Au in solid solution can be documented. Selenium and Te concentrations in bornite may be as high as several thousand ppm and correlate with the abundance of selenides and tellurides within the sample. Selenium distributions show some promise as a vector in exploration, offering the possibility to track a fluid source. Bornite and chalcocite are poor hosts for a range of other elements such as Co, Ni, Ga and Ge, etc. which have been reported to be commonly substituted within sulfides. Hypogene bornite and chalcocite may have significantly different trace element geochemical signatures from secondary (supergene) bornite.  相似文献