Coordinated Observations of Comet Hale–Bopp between 32 and 860 GHz     

Wink  J. E.  Altenhoff  W. J.  Bieging  J.  Butler  B.  Butner  H.  Haslam  C.G.T.  Kreysa  E.  Martin  R.  Mauersberger  R.  McMullin  J.  Muders  D.  Peters  W.  Schmidt  J.  Schraml  J. B.  Sievers  A.  Stumpff  P.  Von Kapp-Herr  A.  Thum  C.  Zylka  R. 《Earth, Moon, and Planets》1997,77(3):165-165

Earth, Moon, and Planets - The concept of simultaneous multifrequency continuum observations, successfully tested on Comet Hyakutake, was applied to Comet Hale-Bopp, using the Heinrich Hertz...  相似文献   

A classification of lunar rock and glass samples using theG-mode central method     

R. Bianchi  J. C. Butler  A. Coradini  A. I. Gavrishin 《Earth, Moon, and Planets》1980,22(3):305-322

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Inherent Limitations of Hydraulic Tomography     

Geoffrey C. Bohling  James J. Butler Jr. 《Ground water》2010,48(6):809-824

We offer a cautionary note in response to an increasing level of enthusiasm regarding high-resolution aquifer characterization with hydraulic tomography. We use synthetic examples based on two recent field experiments to demonstrate that a high degree of nonuniqueness remains in estimates of hydraulic parameter fields even when those estimates are based on simultaneous analysis of a number of carefully controlled hydraulic tests. We must, therefore, be careful not to oversell the technique to the community of practicing hydrogeologists, promising a degree of accuracy and resolution that, in many settings, will remain unattainable, regardless of the amount of effort invested in the field investigation. No practically feasible amount of hydraulic tomography data will ever remove the need to regularize or bias the inverse problem in some fashion in order to obtain a unique solution. Thus, along with improving the resolution of hydraulic tomography techniques, we must also strive to couple those techniques with procedures for experimental design and uncertainty assessment and with other more cost-effective field methods, such as geophysical surveying and, in unconsolidated formations, direct-push profiling, in order to develop methods for subsurface characterization with the resolution and accuracy needed for practical field applications.  相似文献   

Depositional processes across the Sinú Accretionary Prism,offshore Colombia     

Jamie S. Vinnels  Robert W.H. Butler  William D. McCaffrey  Douglas A. Paton 《Marine and Petroleum Geology》2010,27(4):794-809

The Pliocene to Recent of the Sinú Accretionary Prism, offshore Colombia, features gravity current dominated basins characterised primarily by channel- and sheet-like architectures and those with dominantly hemipelagic fills. The prism is fed by rivers that drain from uplifted older basins and volcanic Andean terranes to the south and east which source large volumes of sediment to the Colombian Shelf into the Colombian Basin. Some basin fills show evidence of both localised fold-induced sediment failure and regional-scale shelf collapse, both related to the generation and destruction of oversteepened slopes. Large scale collapses can create new sediment routing pathways and/or local depocentres into which sediment subsequently accumulates. In the Colombian Basin, even relatively distal basins show evidence of channel activity related primarily to the creation of new sediment distribution pathways through breaches in the substrate barriers between basins. These channels are often orientated parallel to the regional drainage trend, suggesting that regional sediment transport trends can assert themselves relatively early in a basin filling history regardless of the local bathymetric grain. While, at a regional scale, sediment dispersal fairways reflect drainage from the continental shelf to the basin floor, intraslope basins form local bathymetric obstructions that can drive local spatial variations in sediment distribution. Thus, both local and regional length scales of bathymetric control are evident within the intraslope basins of the Sinú Accretionary Prism. Although regional dispersal patterns generally become more important in time, individual intraslope basins exhibit more complex filling histories because events such as sill or shelf collapse may serve to disrupt established distribution pathways, initiating repeated episodes of adjustment.  相似文献   

Benchmarking sustainability in cities: The role of indicators and future scenarios     

Christopher T. Boyko  Mark R. Gaterell  Austin R.G. Barber  Julie Brown  John R. Bryson  David Butler  Silvio Caputo  Maria Caserio  Richard Coles  Rachel Cooper  Gemma Davies  Raziyeh Farmani  James Hale  A. Chantal Hales  C. Nicholas Hewitt  Dexter V.L. Hunt  Lubo Jankovic  Ian Jefferson  Joanne M. Leach  D. Rachel Lombardi  Christopher D.F. Rogers 《Global Environmental Change》2012,22(1):245-254

Scenarios are a useful tool to help think about and visualise the future and, as such, are utilised by many policymakers and practitioners. Future scenarios have not been used to explore the urban context in much depth, yet have the potential to provide valuable insights into the robustness of decisions being made today in the name of sustainability. As part of a major research project entitled Urban Futures, a toolkit has been developed in the UK to facilitate the use of scenarios in any urban context and at any scale relevant to that context. The toolkit comprises two key components, namely, (i) a series of indicators comprising both generic and topic area-specific indicators (e.g., air quality, biodiversity, density, water) that measure sustainability performance and (ii) a list of characteristics (i.e., 1–2-sentence statements about a feature, issue or small set of issues) that describe four future scenarios. In combination, these two components enable us to measure the performance of any given sustainability indicator, and establish the relative sensitivity or vulnerability of that indicator to the different future scenarios. An important aspect of the methodology underpinning the toolkit is that it is flexible enough to incorporate new scenarios, characteristics and indicators, thereby allowing the long-term performance of our urban environments to be considered in the broadest possible sense.  相似文献   

运用LANDSAT ETM+和ASTER数据进行岩性分类   总被引：5，自引：0，他引：5  

余海阔  李培军 《岩石学报》2010,26(1):345-351

本文评价了运用ASTER和LANDSAT ETM+数据进行岩性制图的性能。分别利用ASTER数据不同波段区图像及其组合,以及ETM+数据进行岩性分类,并探讨了将ASTER和ETM+数据叠加在一起进行了岩性分类; 利用现有地质图对所有分类结果进行了定量评价。结果表明,ASTER数据不同波段的岩性识别能力不同,并且较ETM+数据能更准确地识别岩性。更重要的是,把ASTER与ETM+数据结合在一起进行岩性分类,可获得比用任一数据单独分类更高的分类精度,表明二者的光谱特征具有一定的互补性。  相似文献   

塔里木盆地库鲁克塔格地区二叠纪末-中三叠世基性岩床的发现及其地质意义   总被引：2，自引：1，他引：1  

边伟华  王璞珺  孙晓猛  唐华风 《岩石学报》2010,26(1):274-282

新疆塔里木盆地东北缘库鲁克塔格地区的中寒武统莫合尔山组沉积地层中发现三条形成于二叠纪末到中三叠世的基性岩床。三条岩床沿沉积岩层面顺层侵入,按照从下到上的顺序,分别为辉绿岩床(厚3m)、辉长岩床(厚20m)和粗玄岩床(厚2.5m)。三条岩床的地球化学特征相似,稀土含量高(∑REE=210×10^-6~297×10^-6),轻稀土元素富集((La/Yb)_N =13.54~17.96),Eu负异常不明显(δEu=0.97~1.21),Ce稍具正异常(δCe=1.11~1.25)。大离子亲石元素(Rb、Ba、Th、Sr)富集,Sr具明显正异常; Ta、Nb和Hf具负异常。低氧化度(0.13~0.40)。三条岩床为同源岩浆活动的产物,岩浆源于上地幔或下地壳,但有下陆壳成分混染。三个样品的MgO含量在4%~6%之间,Mg^#值在37.6~55.6之间,固结指数SI值位于18.7~29.3之间,反映原始的岩浆经历了比较明显的分异作用。粗玄岩床K-Ar年龄为255.2±7.3Ma,辉绿岩床K-Ar年龄为242.8±5.7Ma,辉长岩床Ar-Ar年龄为229.7±3.7Ma。本次岩浆侵入事件发生在南天山洋闭合之后,构造背景为造山后碰撞伸展环境。  相似文献   

Are the teleconnections of Central Pacific and Eastern Pacific El Niño distinct in boreal wintertime?     

C. I. Garfinkel  M. M. Hurwitz  D. W. Waugh  A. H. Butler 《Climate Dynamics》2013,41(7-8):1835-1852

A meteorological reanalysis dataset and experiments of the Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM) are used to study the boreal winter season teleconnections in the Pacific-North America region and in the stratosphere generated by Central Pacific and Eastern Pacific El Niño. In the reanalysis data, the sign of the North Pacific and stratospheric response to Central Pacific El Niño is sensitive to the composite size, the specific Central Pacific El Niño index used, and the month or seasonal average that is examined, highlighting the limitations of the short observational record. Long model integrations suggest that the response to the two types of El Niño are similar in both the extratropical troposphere and stratosphere. Namely, both Central Pacific and Eastern Pacific El Niño lead to a deepened North Pacific low and a weakened polar vortex, and the effects are stronger in late winter than in early winter. However, the long experiments do indicate some differences between the two types of El Niño events regarding the latitude of the North Pacific trough, the early winter polar stratospheric response, surface temperature and precipitation over North America, and globally averaged surface temperature. These differences are generally consistent with, though smaller than, those noted in previous studies.  相似文献   

INTRAREGIONAL VARIABILITY OF TEMPERATURES AS AN ELEMENT OF MICROCLIMATE     

Orton C. Butler 《The Professional geographer》1971,23(4):298-300

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Updated opacities from the Opacity Project     

N. R. Badnell  M. A. Bautista  K. Butler  F. Delahaye  C. Mendoza  P. Palmeri †  C. J. Zeippen  M. J. Seaton 《Monthly notices of the Royal Astronomical Society》2005,360(2):458-464

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