The surfaces of Larissa and Proteus     

Philip J. Stooke 《Earth, Moon, and Planets》1994,65(1):31-54

Topographic models of Neptune's small inner satellites Larissa and Proteus were derived from the shapes of limbs and terminators in Voyager images, modified locally to accomodate large craters and ridges. The models are presented here in tabular and graphic form, including the first map of Larissa and the first detailed relief map of Proteus. The shape of Larissa is approximated by a triaxial ellipsoid with axes of 208, 192 and 178 km, but is only weakly constrained by the single available view. The volume is estimated to be 3.5 ± 1.0 × 10⁶ km³. The surface is heavily cratered and may be crossed by one or two poorly seen linear ridges. Proteus is approximated by a triaxial ellipsoid with axes of 424, 390 and 396 km (the latter being the rotation axis dimension). The volume is estimated to be 3.4 ± 0.4 × 10⁷ km³. Its surface appears to be very heavily cratered and extensive evidence for linear fractures is observed despite very low image quality.  相似文献   

The concise Oxford dictionary of earth sciences. A. Allaby and M. Allaby. Publisher Oxford University Press 1990 £20.00 ISBN 0 19 866146 0     

Philip Gibbard 《第四纪科学杂志》1991,6(1):79-80

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Migrants,manufacturing and metropolitan labour markets in Australia     

Philip S. Morrison 《The Australian geographer》1990,21(2):151-163

While the experience of migrants in the Australian labour market has received considerable attention, few researchers have asked how uniform this experience has been across the country's major metropolitan labour markets. This paper shows that migrants employed in the manufacturing sector exhibit noticeable differences in their relative access to jobs in different parts of the country. This evidence raises a number of questions about the appropriate scale within which to consider the labour participation and occupational selection experience of migrant men and women.  相似文献   

    

Philip E. LaMoreaux 《Environmental Geology》1995,25(4):287

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Erratum     

Philip Brown  Eric J. Essene  Donald R. Peacor 《Contributions to Mineralogy and Petrology》1979,68(4):441-441

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A simple analytical approximation to the temperature structure in subduction zones   总被引：1，自引：0，他引：1  

Philip England  Catherine Wilkins 《Geophysical Journal International》2004,159(3):1138-1154

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Seismic reflection imaging of thin, kimberlite dykes and sills: exploration and deposit characterization of the Snap Lake dyke, Canada     

Philip T.C. Hammer  Ron M. Clowes  Kumar Ramachandran   《Lithos》2004,76(1-4):359-367

Seismic reflection techniques are, for the first time, used to image a thin, diamondiferous, kimberlite dyke from subcrop to depths greater than 1300 m. Exploration for vertical kimberlite pipes generally utilizes potential field techniques that often fail to reveal subhorizontal or shallow-dipping intrusions. In contrast, seismic reflection methods are well suited for imaging targets with this geometry. Therefore, in order to evaluate seismic reflection as a tool for subhorizontal kimberlite dyke/sill exploration and mine planning, a feasibility study and subsequent seismic survey were undertaken on the diamondiferous Snap Lake dyke (Northwest Territories, Canada). A substantial drilling program has mapped the dyke as a gently dipping sheet that averages 2–3 m in thickness. The detailed structural and composition data available at Snap Lake provides a unique opportunity to test reflection techniques on a well-sampled deposit. The feasibility study involved measuring P-velocities and densities of cores drilled from the kimberlite and host rocks. These data were used to model reflection amplitudes, evaluate resolution limitations, and determine the acquisition parameters for the reflection survey. Two 2-D lines were acquired that provide comparative datasets for different sources (explosive and vibroseis) and ground types (land and lake ice). In addition, the exploration-scale survey incorporated high fold (40–260 nominal) and long offsets (3260 m). The explosive-source profile recorded on land yielded a superb image of the dyke from depths of 60 m to more than 1300 m over a lateral distance of 5700 m. The seismic image correlates well with adjacent drill hole data and adds considerable detail to the topography of the kimberlite sheet determined by drilling. The vibroseis source also imaged the dyke, but only when sources and geophones were on land; the dyke was not imaged beneath the ice due to reverberation and attenuation effects. The frequency response and unusually strong reflection amplitudes from the dyke indicate the importance of tuning effects and multiples for this type of target and acquisition environment. Apparent correlations between reflection amplitudes and dyke structure (e.g., thickness, feathering, 3-D geometry) suggest that seismic reflection data may be valuable for guiding drilling programs. The results demonstrate that, in the appropriate situation, seismic methods have great potential for use in kimberlite exploration, subsurface mapping, and detailed imaging for mine development purposes.  相似文献   

Active faulting and natural hazards in Armenia, eastern Turkey and northwestern Iran   总被引：1，自引：0，他引：1  

Arkady S. Karakhanian  Vladimir G. Trifonov  Herve Philip  Ara Avagyan  Khaled Hessami  Farshad Jamali  M. Salih Bayraktutan  H. Bagdassarian  S. Arakelian  V. Davtian  A. Adilkhanyan 《Tectonophysics》2004,380(3-4):189-219

Active fault zones of Armenia, SE Turkey and NW Iran present a diverse set of interrelated natural hazards. Three regional case studies in this cross-border zone are examined to show how earthquakes interact with other hazards to increase the risk of natural disaster. In northern Armenia, a combination of several natural and man-made phenomena (earthquakes, landslides and unstable dams with toxic wastes) along the Pambak-Sevan-Sunik fault (PSSF) zone lowers from 0.4 to 0.2–0.3g the maximum permissible level (MPL) of seismic hazard that may induce disastrous destruction and loss of life in the adjacent Vanadzor depression.

In the Ararat depression, a large active fault-bounded pull-apart basin at the junction of borders of Armenia, Turkey, Iran and Azerbaijan, an earthquake in 1840 was accompanied by an eruption of Ararat Volcano, lahars, landslides, floods, soil subsidence and liquefaction. The case study demonstrates that natural hazards that are secondary with respect to earthquakes may considerably increase the damage and the casualties and increase the risk associated with the seismic impact.

The North Tabriz–Gailatu fault system poses a high seismic hazard to the border areas of NW Iran, eastern Turkey, Nakhichevan (Azerbaijan) and southern Armenia. Right-lateral strike–slip motions along the North Tabriz fault have given rise to strong earthquakes, which threaten the city of Tabriz with its population of 1.2 million.

The examples illustrate how the concentration of natural hazards in active fault zones increases the risk associated with strong earthquakes in Armenia, eastern Turkey and NW Iran. This generally occurs across the junctions of international borders. Hence, the transboundary character of active faults requires transboundary cooperation in the study and mitigation of the natural risk.  相似文献   

Palaeoecology of Africa and the surrounding islands,Volume 26, Proceedings of the Third Conference on African Palynology,Johannesburg, 14–19 September 1997, edited by Klaus Heine,Balkema, Rotterdam, 1999. No. of pages: 260. Price: $90, £53. ISBN 90 5410 476 7     

Philip Barker 《地球表面变化过程与地形》2001,26(5):581-581

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An Application of Bayesian Inverse Methods to Vertical Deconvolution of Hydraulic Conductivity in a Heterogeneous Aquifer at Oak Ridge National Laboratory   总被引：2，自引：0，他引：2  

Michael N. Fienen  Peter K. Kitanidis  David Watson  Philip Jardine 《Mathematical Geology》2004,36(1):101-126

A Bayesian inverse method is applied to two electromagnetic flowmeter tests conducted in fractured weathered shale at Oak Ridge National Laboratory. Traditional deconvolution of flowmeter tests is also performed using a deterministic first-difference approach; furthermore, ordinary kriging was applied on the first-difference results to provide an additional method yielding the best estimate and confidence intervals. Depth-averaged bulk hydraulic conductivity information was available from previous testing. The three methods deconvolute the vertical profile of lateral hydraulic conductivity. A linear generalized covariance function combined with a zoning approach was used to describe structure. Nonnegativity was enforced by using a power transformation. Data screening prior to calculations was critical to obtaining reasonable results, and the quantified uncertainty estimates obtained by the inverse method led to the discovery of questionable data at the end of the process. The best estimates obtained using the inverse method and kriging compared favorably with first-difference confirmatory calculations, and all three methods were consistent with the geology at the site.  相似文献