Forum on Nancy Krieger’s geospatial approach to social epidemiology: an introduction     

Daniel Sui  James Holt 《GeoJournal》2009,74(2):85-85

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A newly discovered active contact binary in the field of NGC 1348     

Xiang-Song Fang  Sheng-Hong Gu  Ho-Keung Hui  Chi-Tai Kwok  Bill Yeung  Kam-Cheung Leung 《天体物理学报》2012,(1):93-103

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Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131−36)     

B. H. C. Emonts  R. Morganti  T. A. Oosterloo  J. Holt  C. N. Tadhunter  J. M. van der Hulst  R. Ojha  E. M. Sadler 《Monthly notices of the Royal Astronomical Society》2008,387(1):197-208

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GOES—8／9大气垂直探测在天气预报和临近预报中的应用     

Menz.  WP 周培 《气象科技》2000,28(2):9-16

自１９９４年４月以来，新一代静止气象卫星大气垂直探测器一直在１８个红外谱段测量大气辐射，提供了研究海洋与大气的能力，其能力大大超出上一代ＧＯＥＳ。Ｍｅｎｚｅｌ和Ｐｕｒｄｏｍ预见到了ＧＯＥＳ－８／９大气探测器多项可能的改进。本文论述了取得了一些成果，详细介绍了大气探测器的飞行性能，给出了经业务定期可得的试验产品，并描述了它们对临近预报和天气预报扔影响。  相似文献   

Robert F. Howard,In The Footsteps of Hale Prologue     

Livingston  Bill 《Solar physics》1999,188(2):219-224

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Field palaeontology by Roland Goldring,Longman, Harlow, 1999. No. of pages: 208. Price: £21.99. ISBN 0582 35625 3.     

Bill Austin 《地球表面变化过程与地形》2001,26(1):109-109

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Using constrained inversion of gravity and magnetic field to produce a 3D litho‐prediction model          下载免费PDF全文

Omid Mahmoodi  Richard S. Smith  Bill Spicer 《Geophysical Prospecting》2017,65(6):1662-1679

Geologically constrained inversion of gravity and magnetic field data of the Victoria property (located in Sudbury, Canada) was undertaken in order to update the present three‐dimensional geological model. The initial and reference model was constructed based on geological information from over 950 drillholes to constrain the inversion. In addition, downhole density and magnetic susceptibility measured in six holes were statistically analysed to derive lower and upper bounds on the physical properties attributed to the lithological units in the reference model. Constrained inversion of the ground gravity and the airborne magnetic data collected at the Victoria property were performed using GRAV3D and MAG3D, respectively. A neural network was trained to predict lithological units from the physical properties measured in six holes. Then, the trained network was applied on the three‐dimensional distribution of physical properties derived from the inversion models to produce a three‐dimensional litho‐prediction model. Some of the features evident in the lithological model are remnants of the constraints, where the data did not demand a significant change in the model from the initial constraining model (e.g., the thin pair of diabase dykes). However, some important changes away from the initial model are evident; for example, a larger body was predicted for quartz diorite, which may be related to the prospective offset dykes; a new zone was predicted as sulfide, which may represent potential mineralisation; and a geophysical subcategory of metabasalt was identified with high magnetic susceptibility and high density. The litho‐prediction model agrees with the geological expectation for the three‐dimensional structure at Victoria and is consistent with the geophysical data, which results in a more holistic understanding of the subsurface lithology.  相似文献   

How does water near clay mineral surfaces influence the rock physics of shales?          下载免费PDF全文

Rune M. Holt  Morten I. Kolstø 《Geophysical Prospecting》2017,65(6):1615-1629

Clays and clay‐bearing rocks like shale are extremely water sensitive. This is partly due to the interaction between water and mineral surfaces, strengthened by the presence of nanometer‐size pores and related large specific surface areas. Molecular‐scale numerical simulations, using a discrete‐element model, show that shear rigidity can be associated with structurally ordered (bound or adsorbed) water near charged surfaces. Building on these and other molecular dynamics simulations plus nanoscale experiments from the literature, the water monolayer adjacent to hydrophilic solid surfaces appears to be characterised by shear stiffness and/or enhanced viscosity. In both cases, elastic wave propagation will be affected by the bound or adsorbed water. Using a simple rock physics model, bound water properties were adjusted to match laboratory measured P‐ and S‐wave velocities on pure water‐saturated kaolinite and smectite. To fit the measured stress sensitivity, particularly for kaolinite, the contribution from solid‐grain contact stiffness needs to be added. The model predicts, particularly for S‐waves, that viscoelastic bound water could be a source of dispersion in clay and clay‐rich rocks. The bound‐water‐based rock physics model is found to represent a lower bound to laboratory‐measured velocities obtained with shales of different mineralogy and porosity levels.  相似文献   

Potential of legacy 2D seismic data for deep targeting and structural imaging at the Neves–Corvo massive sulphide-bearing deposit,Portugal     

George A. Donoso  Alireza Malehmir  Nelson Pacheco  Vitor Araujo  Matthew Penney  Joao Carvalho  Bill Spicer  Steve Beach 《Geophysical Prospecting》2020,68(1):44-61

Seismic methods are becoming an established choice for deep mineral exploration after being extensively tested and employed for the past two decades. To investigate whether the early European mineral-exploration datasets had potential for seismic imaging that was overlooked, we recovered a low-fold legacy seismic dataset from the Neves–Corvo mine site in the Iberian Pyrite Belt in southern Portugal. This dataset comprises six 4–6 km long profiles acquired in 1996 for deep targeting. Using today's industry-scale processing algorithms, the world-class, ca. 150 Mt, Lombador massive sulphide and other smaller deposits were better imaged. Additionally, we also reveal a number of shallow but steeply dipping reflections that were absent in the original processing results. This study highlights that legacy seismic data are valuable and should be revisited regularly to take advantage of new processing algorithms and the experiences gained from processing such data in hard-rock environments elsewhere. Remembering that an initial processing job in hard rock should always aim to first obtain an overall image of the subsurface and make reflections visible, and then subsequent goals of the workflow could be set to, for example understanding relative amplitude ratios. The imaging of the known mineralization implies that this survey could likely have been among one of the pioneer studies in the world that demonstrated the capability of directly imaging massive sulphide deposits using the seismic method.  相似文献   

The structural,geometric and volumetric changes of a polythermal Arctic glacier during a surge cycle: Comfortlessbreen,Svalbard          下载免费PDF全文

Owen King  Michael J. Hambrey  Tristram D. L. Irvine‐Fynn  Tom O. Holt 《地球表面变化过程与地形》2016,41(2):162-177

Various parameters of the most recent surge of the polythermal glacier Comfortlessbreen in northwest Svalbard, have been assessed through a combination of remote sensing and ground observations. Analysis of a digital elevation model time‐series shows a marked change in the geometry of the glacier from quiescence (1990 and earlier) into the late surge phase (2009). The transfer of 0.74 km³ of ice caused up to 80 m of surface drawdown in the reservoir area, above the equilibrium line, whilst ice built up in a spatially concentrated manner in the receiving zone, below the equilibrium line. A ramp of ice, c. 100 m above quiescent level, developed in the lower reaches of the glacier late in the surge. Also in the lower reaches of the glacier, structures attributable to the passage of a kinematic wave are identified and the migration of a surge front on the glacier is thus inferred. In a conceptual model, we consider that a bend in the valley, in which the glacier resides, and convergence with tributary glaciers, to be significant factors in the style of surge evolution. Their flow‐restrictive interference results in slow initial mass‐transfer and the growth of a surge front within 3–4 km of the terminus. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献