Strains developed in the hangingwalls of thrusts due to their slip/propagation rate: a dislocation model: reply     

T.J Chapman  G.D Williams 《Journal of Structural Geology》1985,7(6):759-762

Folding related to the propagation of thrusts is common in thrust belts, including the Rocky Mountains. The rare development of such folds in the southern Rockies, due to lithological control, is a special case of the dislocation/ductile bead model, which, it is argued, is of general applicability.  相似文献   

HAZMAP: A REMOTE DIGITAL MEASUREMENT SYSTEM FOR WORK IN HAZARDOUS ENVIRONMENTS     

D. P. Chapman  A. T. D. Deacon  A. Hamid 《The Photogrammetric Record》1994,14(83):747-758

In a continuing drive to reduce the radiation exposure of nuclear workers, many routine aspects of nuclear plant maintenance and refurbishment are increasingly undertaken by robotic or remote handling tools. Accurate “as built” documentation of plant records is vital to the successful planning and execution of such operations since an unexpected obstruction or undocumented site modification may result in a costly disruption or even failure of the intervention. In recognition of the importance of such documentation, a recent European Community ? ? Teleman-Robotics and remote sensing operations in hazardous nuclear environments
sponsored project has been directed towards the development of techniques for cost effective survey and modelling of such plant. This paper will detail the rationale behind the design of such a system and will describe typical results from a number of pilot projects.  相似文献   

Solar irradiance from Nimbus-7 compared with ground-based photometry     

G. A. Chapman  A. M. Cookson  D. V. Hoyt 《Solar physics》1994,149(2):249-255

We have compared total solar irradiance from Nimbus-7 with ground-based photometry from the San Fernando Observatory (SFO) for 109 days between June 1 and December 31, 1988. We have also included in some analyses NOAA-9 SBUV2 data orF10.7 radio flux. The Nimbus-7 data are from orbital samples, averaged to the mean time of observation at SFO. Using the same parameters as in Chapmanet al. (1992), the multiple regression gives anR ² = 0.9131 and a solar minimum irradiance,S ₀, = 1371.76 ± 0.18 W m^–2 for the best fit.  相似文献   

Taxonomy of asteroids     

Edward Bowell  Clark R. Chapman  Jonathan C. Gradie  David Morrison  Benjamin Zellner 《Icarus》1978,35(3):313-335

A taxonomic system was introduced by C. R. Chapman, D. Morrison, and B. Zellner [Icarus25, 104–130 (1975)], in which minor planets are classified according to a few readily observable optical properties, independent of specific mineralogical interpretations. That taxonomy is here augmented to five classes, now precisely defined in terms of seven parameters obtained from polarimetry, spectrophotometry, radiometry, and UBV photometry of 523 objects. We classify 190 asteroids as type C, 141 as type S, 13 as type M, 3 as type E, and 3 as type R; 55 objects are shown to fall outside these five classes and are designated U (unclassifiable). For the remaining 118, the data exclude two or more types but are insufficient for unambiguous classification. Reliable diameters, from radiometry or polarimetry or else from albedos adopted as typical of the types, are listed for 396 objects. We also compare our taxonomy with other ones and discuss how classification efforts are related to the interpretation of asteroid mineralogies.  相似文献   

Modelling frequency-dependent seismic anisotropy in fluid-saturated rock with aligned fractures: implication of fracture size estimation from anisotropic measurements   总被引：5，自引：0，他引：5  

Sonja Maultzsch  Mark Chapman  Enru Liu  Xiang Yang Li 《Geophysical Prospecting》2003,51(5):381-392

Measurements of seismic anisotropy in fractured rock are used at present to deduce information about the fracture orientation and the spatial distribution of fracture intensity. Analysis of the data is based upon equivalent-medium theories that describe the elastic response of a rock containing cracks or fractures in the long-wavelength limit. Conventional models assume frequency independence and cannot distinguish between microcracks and macrofractures. The latter, however, control the fluid flow in many subsurface reservoirs. Therefore, the fracture size is essential information for reservoir engineers. In this study we apply a new equivalent-medium theory that models frequency-dependent anisotropy and is sensitive to the length scale of fractures. The model considers velocity dispersion and attenuation due to a squirt-flow mechanism at two different scales: the grain scale (microcracks and equant matrix porosity) and formation-scale fractures. The theory is first tested and calibrated against published laboratory data. Then we present the analysis and modelling of frequency-dependent shear-wave splitting in multicomponent VSP data from a tight gas reservoir. We invert for fracture density and fracture size from the frequency dependence of the time delay between split shear waves. The derived fracture length matches independent observations from borehole data.  相似文献   

Observation and analysis of frequency-dependent anisotropy from a multicomponent VSP at Bluebell-Altamont field, Utah   总被引：1，自引：0，他引：1  

E. Liu  J. H. Queen  X. Y. Li  M. Chapman  S. Maultzsch  H. B. Lynn  E. M. Chesnokov   《Journal of Applied Geophysics》2003,54(3-4):319

In this paper, we present results from the analysis of a multicomponent VSP from a fractured gas reservoir in the Bluebell-Altamont Field, Utah. Our analysis is focused on frequency-dependent anisotropy. The four-component shear-wave data are first band-pass filtered into different frequency bands and then rotated to the natural coordinates so that the fast and slow shear-waves are effectively separated. We find that the polarisations of the fast shear-waves are almost constant over the whole depth interval, and show no apparent variation with frequency. In contrast, the time delays between the split shear-waves decrease as the frequency increases. A linear regression is then applied to fit the time-delay variations in the target and we find that the gradients of linear fits to time delays show a decrease as frequency increases. Finally, we apply a time-frequency analysis method based on the wavelet transform with a Morlet wavelet to the data. The variation of shear-wave time delays with frequency is highlighted in the time-delay and frequency spectra. We also discuss two mechanisms giving rise to dispersion and frequency-dependent anisotropy, which are likely to explain the observation. These are scattering of seismic waves by preferentially aligned inhomogeneneities, such as fractures or fine layers, and fluid flow in porous rocks with micro-cracks and macro-fractures.  相似文献   

Chemical and isotopic evaluation of water sources to the fens of South Park,Colorado   总被引：1，自引：0，他引：1  

Jenny B. Chapman  Brent Lewis  Greg Litus 《Environmental Geology》2003,43(5):533-545

  相似文献   

Derivation of a microstructural poroelastic model   总被引：7，自引：0，他引：7  

Mark Chapman  Sergei V. Zatsepin  Stuart Crampin 《Geophysical Journal International》2002,151(2):427-451

  相似文献   

浅谈遥感应用领域对卫星影像的要求     

王伟娜  葛莹  李心玉  张淑辉 《测绘与空间地理信息》2008,31(3)

卫星遥感影像在国民经济建设诸多行业中的应用日益广泛,这种广泛性使得行业对卫星遥感数据提出了不同的要求。本文主要从空间分辨率、时间分辨率、光谱分辨率和影像质量等方面对其进行阐述。  相似文献   

Metrics for characterizing network structure and node importance in Spatial Social Networks     

Dipto Sarkar  Clio Andris  Colin A. Chapman  Raja Sengupta 《International journal of geographical information science》2019,33(5):1017-1039

Social Network Analysis offers powerful tools to analyze the structure of relationships between a set of people. However, the addition of spatial information poses new challenges, as nodes are embedded simultaneously in network space and Euclidean space. While nearby nodes may not form social ties, ties may exist at a distance, a configuration ill-suited for traditional spatial metrics that assume adjacent objects are related. As such, there are relatively few metrics to describe these nuanced situations. We advance the burgeoning field of spatial social network analysis by introducing a set of new metrics. Specifically, we introduce the spatial social network schema, tuning parameter and the flattening ratio, each of which leverages the notion of ‘distance’ to augment insights obtained by relying on topology alone. These methods are used to answer the questions: What is the social and spatial structure of the network? Who are the key individuals at different spatial scales? We use two synthetic networks with properties mimicking the ones reported in the literature as validation datasets and a case study of employer–employee network. The methods characterize the employer–employee as spatially loose with predominantly local connections and identify key individuals responsible for keeping the network connected at different spatial scales.  相似文献