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智利是世界上部分大地震的发生地:那里大概平均每十年就会发生一次8级地震。这些地震都发生在俯冲带:有的发生在南美和Nazca板块之间的界面上,称为板问破裂;有的发生在Nazca俯冲板块内部,称为板内事件。每个世纪都会发生几次巨大的板内、 相似文献
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Slope failure or landslide is a complex geological/geotechnical problem that involves much uncertainty. In this work, a framework for probabilistic assessment of landslide is presented with a focus on the El Berrinche landslide, Honduras. One unique feature of this case study involving the El Berrinche landslide is that the stability analysis has to be carried out with limited data. Another challenge in this study is to assess possible remedial measures in a way that can easily be communicated to the government and the public. A reliability-based framework for a probabilistic assessment is proposed. With this approach, different levels of risk for landslide are assessed and the associated costs are estimated; and all information is integrated into the decision-making process for choosing a remedial action. 相似文献
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Jiping LIU David BROMWICH Dake CHEN Raul CORDERO Thomas JUNG Marilyn RAPHAEL John TURNER Qinghua YANG 《大气科学进展》2020,37(5):421-422
<正>The Antarctic, including the continent of Antarctica and the Southern Ocean, is a critically important part of the Earth system. Research in Antarctic meteorology and climate has always been a challenging endeavor. Studying and predicting weather patterns in the Antarctic are important for understanding their role in local-to-global processes and facilitating field 相似文献
46.
The concept of equilibrium plan form and equilibrium profile has been widely used as an engineering tool in order to design beach nourishment projects. The scope of this paper is to further explore this “equilibrium beach” concept in crenulated bays, as a long-term tool for beach nourishment projects. The proposed methodology is based on González and Medina (2001) and combines the static equilibrium plan and profile for long-term analysis. This methodology includes a modified equilibrium plan form, which is able to define the orientation of the local wave front in the diffracting point, and also to locate the downcoast starting point of the static equilibrium beach from which the parabolic plan form of Hsu and Evans (1989) is valid. This methodology permits the application of any equilibrium profile formulation. An example of the application of this methodology and long-term formulations to the design of the Spanish nourishment project of Poniente Beach (Gijón) is presented. Ten years after its construction, the beach has still got a static equilibrium and remains pretty close to the predicted equilibrium beach in plan and profile. 相似文献
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The utility of nonmetric, multidimensional-scaling techniques is demonstrated for the analysis and collection of environmental-cognition data. By comparing the multidimensional-scaling solutions of a real-setting map to scaling solutions for sketch maps and two psychophysical, distance-scaling procedures, we demonstrate that magnitude estimation of actual interpoint distances is comparable in accuracy to sketch maps when produced without constraints, or when subjects are given a specified list of landmarks to include on their maps. Triadic comparisons of actual interpoint distances were less accurate than the three other techniques. 相似文献
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Raul Mollehuara Canales Huade Guan Erick Bestland John Hutson Craig T. Simmons 《Environmental Earth Sciences》2013,68(8):2301-2312
In this study, arsenic adsorption to an Australian laterite has been examined for a particle-size range between 38 μm and 25 mm. The results show that particle size influences both kinetic and equilibrium characteristics of arsenic adsorption. The equilibrium adsorption capacity increases from around 100 mg kg?1 for laterite particles coarser than 4 mm, to around 160 mg kg?1 for laterite particles between 75 μm and 4 mm, and to over 200 mg kg?1 for laterite particles finer than 75 μm. The kinetic adsorption data can be fitted with the pseudo-second-order reaction model, in particular for finer particles where the film diffusion and/or surface reaction are important processes. The model-fitted rate constant remains steady for laterite particles coarser than 2 mm, increases moderately with particle size in the range between 75 μm and 2 mm, and increases dramatically for laterite particles finer than 75 μm. These arsenic adsorption behaviours can be explained by the relative importance of two particle-size-dependent processes: quick external-surface adsorption (more important for fine particles) and slow intraparticle adsorption (more important for coarse particles). Most of the external-surface adsorption completes in the first hour of the experiment. To apply the studied laterite for dissolved arsenic removal, it is recommended that fine particles, in particular finer than 75 μm, should be used if the contact time is the limitation, and that coarse particles, in particular 2–4 mm, should be used if sufficient contact time is available. 相似文献
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Michael Pierce Terry Bridges Duncan A. Forbes Robert Proctor Michael A. Beasley Karl Gebhardt Favio Raul Faifer Juan Carlos Forte Stephen E. Zepf Ray Sharples David A. Hanes 《Monthly notices of the Royal Astronomical Society》2006,368(1):325-334
NGC 4649 (M60) is one of a handful of giant Virgo ellipticals. We have obtained Gemini/GMOS (Gemini North Multi-Object Spectrograph) spectra for 38 globular clusters (GCs) associated with this galaxy. Applying the multi-index χ2 minimization technique of Proctor and Sansom with the single stellar population models of Thomas, Maraston and Korn, we derive ages, metallicities and α-element abundance ratios. We find several young (2–3 Gyr old) supersolar metallicity GCs, while the majority are old (>10 Gyr), spanning a range of metallicities from solar to [Z/H]=−2 . At least two of these young GCs are at large projected radii of 17–20 kpc. The galaxy itself shows no obvious signs of a recent starburst, interaction or merger. A trend of decreasing α-element ratio with increasing metallicity is found. 相似文献
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