Global standard names for the Lowermost Cambrian Series and Stage     

Ed Landing Shanchi Peng Loren E. Babcock Gerd Geyer Malgorzata Moczydlowska- Vidal 《《幕》》2007,30(4):287-289

  相似文献   

A Small‐Diameter NMR Logging Tool for Groundwater Investigations     

David Walsh  Peter Turner  Elliot Grunewald  Hong Zhang  James J. Butler Jr.  Ed Reboulet  Steve Knobbe  Tom Christy  John W. Lane Jr.  Carole D. Johnson  Tim Munday  Andrew Fitzpatrick 《Ground water》2013,51(6):914-926

A small‐diameter nuclear magnetic resonance (NMR) logging tool has been developed and field tested at various sites in the United States and Australia. A novel design approach has produced relatively inexpensive, small‐diameter probes that can be run in open or PVC‐cased boreholes as small as 2 inches in diameter. The complete system, including surface electronics and various downhole probes, has been successfully tested in small‐diameter monitoring wells in a range of hydrogeological settings. A variant of the probe that can be deployed by a direct‐push machine has also been developed and tested in the field. The new NMR logging tool provides reliable, direct, and high‐resolution information that is of importance for groundwater studies. Specifically, the technology provides direct measurement of total water content (total porosity in the saturated zone or moisture content in the unsaturated zone), and estimates of relative pore‐size distribution (bound vs. mobile water content) and hydraulic conductivity. The NMR measurements show good agreement with ancillary data from lithologic logs, geophysical logs, and hydrogeologic measurements, and provide valuable information for groundwater investigations.  相似文献   

Normalized residual displacement spectra for post-mainshock assessment of structures subjected to aftershocks     

Amiri  Saeed  Garakaninezhad  Alireza  Bojórquez  Edén 《地震工程与工程振动(英文版)》2021,20(2):403-421

Residual displacement, as a significant measure of structural inelasticity, is effectively used in post-earthquake seismic assessment of structures. This demand can be considered for seismic evaluation of structures under multiple earthquakes. This study introduces a simple and novel index to predict the residual displacement of mainshock-damaged structures against subsequent aftershock. The proposed index is defined as a ratio between residual displacement of damaged structures against aftershock and peak inelastic displacement of intact structures under mainshock. In this study, constantstrength spectra based on the index are developed considering the effects of important structural characteristics and also significant seismic parameters. Moreover, analytical equations are presented to predict the proposed index for bi-linear single-degree-of-freedom(SDOF) systems considering both the effects of positive and negative polarities of aftershock. Furthermore, an equation is suggested to estimate the peak inelastic displacement of intact systems under mainshock, which is required to compute the index.  相似文献   

The Oxford–Dartmouth Thirty Degree Survey – I. Observations and calibration of a wide-field multiband survey     

Emily C. MacDonald  Paul Allen  Gavin Dalton  Leonidas A. Moustakas  Catherine Heymans  Edward Edmondson  Chris Blake  Lee Clewley  Molly C. Hammell  Ed Olding  Lance Miller  Steve Rawlings  Jasper Wall  Gary Wegner  Christian Wolf 《Monthly notices of the Royal Astronomical Society》2004,352(4):1255-1272

  相似文献   

Z-dependence of the level intervals in 2s 2 2p 2, 2s 2 2p 3 and 2s 2 2p 4     

Bengt Edĺen 《Solar physics》1972,24(2):356-367

Values of the level intervals in the ground configurations 2s ² 2p ², 2s ² 2p ³ and 2s ² 2p ⁴ have been critically compiled from laboratory observations and from observations of nebular and coronal forbidden transitions. The data are represented within experimental errors by means of semi-empirical extrapolation formulae which contain from 3 to 5 adjusted parameters. The results provide means for checking laboratory and astrophysical identifications and measurements. Tables of best level values are given for the configurations concerned.  相似文献   

Surface influences on the Australian West Coast Trough     

Ma Yimin  T. J. Lyons  J. A. Blockley 《Theoretical and Applied Climatology》2001,68(3-4):207-217

Summary  Three dimensional numerical simulations of the Australian West Coast Trough were conducted using a mesoscale model. These simulations represent the process of formation, development and disappearance of the trough and highlight the role of surface features in trough behaviour. Strong land surface heating strengthens the trough whereas topography and sea surface temperatures are of marginal importance. Diurnal variations in surface heating between the land and ocean lead to the trough line oscillating around the coast whereas its more general eastward movement is synoptically controlled. The sea breeze circulation influences local trough orientation through maritime cooling. Received December 23, 1999 Revised November 7, 2000  相似文献   

Quaternary reactivation of Tertiary faults in the southeastern Korean Peninsula: Age constraint by optically stimulated luminescence dating   总被引：1，自引：0，他引：1  

Jin-Han Ree  Young-Joon Lee  Ed J. Rhodes  Youngdo Park  Sung-Tack Kwon  Ueechan Chwae  Jeong-Soo Jeon  Bongjoo Lee 《Island Arc》2003,12(1):1-12

Abstract   Two groups of Quaternary faults occur in the southeastern Korean Peninsula. The first group is north-northeast-striking, high-angle dextral strike–slip faults. The second group is north-northeast-striking, low-angle reverse faults that represent the reactivation of the pre-existing normal faults. Optically stimulated luminescence dating of Quaternary sediments cut by one of the reverse faults constrains the faulting age to post-32 Ka. These faults seem to be capable of further slip under the current tectonic stress regime, as determined by recent earthquake events in northeast Asia. Therefore, the traditional concept that the southeastern Korean Peninsula is seismically stable should be reappraised.  相似文献   

Visit to the Natural History Museum of Belgium     

Ed.A. Jarzembowski 《Proceedings of the Geologists' Association. Geologists' Association》2002,113(2):175-179

  相似文献   

Geomorphological evolution of the Tilcara alluvial fan (Jujuy Province, NW Argentina): Tectonic implications and palaeoenvironmental considerations     

Carlos Sancho  Jos Luis Pea  Felipe Rivelli  Ed Rhodes  Arsenio Muoz 《Journal of South American Earth Sciences》2008,26(1):68-77

The development and evolution of the Tilcara alluvial fan, in the Quebrada de Humahuaca (Andean Eastern Cordillera, NW Argentina), has been analysed by using geomorphological mapping techniques, sedimentological characterisation of the deposits and OSL chronological methods. It is a complex segmented alluvial fan made up of five evolutionary stages (units Qf1, Qf2, Qf3, Qf4 and Qf5) developed under arid climatic environments as well as compressive tectonic conditions. Segmentation processes, including aggradation/entrenchment cycles and changes in the location of the depositional lobe, are mainly controlled by climatic and/or tectonic changes as well as channel piracy processes in the drainage system. Alluvial fan deposits include debris flows, sheet flows and braided channel facies associated with high water discharge events in an arid environment. The best mean OSL age estimated for stage Qf2 is 84.5 ± 7 ka BP. In addition, a thrust fault affecting these deposits has been recognized and, as a consequence, the compressive tectonics must date from the Upper Pleistocene in this area of the Andean Eastern Cordillera.  相似文献   

Editorial: The Future of Mathematical Geology     

Hohn  Michael Ed. 《Mathematical Geosciences》1998,30(1):1-3

Mathematical Geosciences -  相似文献