High-resolution coastal hazard assessment along the French Riviera from co-seismic tsunamis generated in the Ligurian fault system     

Nemati  Fatemeh  Grilli  Stephan T.  Ioualalen  Mansour  Boschetti  Laurie  Larroque  Christophe  Trevisan  Jenny 《Natural Hazards》2019,96(2):553-586

Natural Hazards - The French Riviera is a densely populated and touristic coast. It is also one of the most seismically active areas of the Western Mediterranean. This is evidenced by the Mw...  相似文献   

Interpretation of spontaneous potential anomalies from some simple geometrically shaped bodies using neural network inversion     

Mansour A. Al-Garni 《Acta Geophysica》2010,58(1):143-162

A new approach is proposed in order to interpret spontaneous potential (self-potential) anomalies related to simple geometric-shaped models such as sphere, horizontal cylinder, and vertical cylinder. This approach is mainly based on using neural network inversion of SP anomalies, particularly modular algorithm, for estimating the parameters of different simple geometrical bodies. However, Hilbert transforms are involved to determine the origin location in order to reduce the parameters which minimize the ambiguity in the inverted models. The inversion has been tested first on synthetic data from different models, using only one well-trained network. The results of inversion show that the parameter values derived by the inversion are identical to the true values of parameters. Noise analysis has been also examined, where the results of the inversion produce acceptable results up to 10% of white Gaussian noise. The validity of the neural network inversion is demonstrated through published real field SP taken from southern Bavarian Woods, Germany. A comparable and acceptable agreement is shown between the results of inversion derived by the neural network and those from the real field data.  相似文献   

Inversion of magnetic anomalies due to isolated thin dike-like sources using artificial neural networks     

Mansour A. Al-Garni 《Arabian Journal of Geosciences》2017,10(15):337

A new approach is proposed to interpret magnetic anomalies caused by isolated thin dike-like causative targets. The approach is essentially based on utilizing artificial neural network (ANN) inversion for estimating the problem parameters. Particularly, the modular neural network (MNN) is used for the inversion process in order to quantitatively interpret the magnetic anomalies. The MNN inversion has been first tested on a synthetic data with and without random white Gaussian noise. The effect of random noise has been clearly investigated where it showed that the approach provided satisfactory results. Furthermore, three field examples have been inverted in order to investigate the applicability of the proposed approach. The results showed good agreement with the techniques that have been stated in the literatures.  相似文献   

Physico-Chemical and Shrinkage Properties of Highly Organic Soil Treated with Non-traditional Additives     

Hossein Moayedi  Mansour Mosallanezhad 《Geotechnical and Geological Engineering》2017,35(4):1409-1419

The changes in the shrinkage and physicochemical properties of untreated and treated organic soil using several chemical additives were investigated. In order to evaluate the effect of each chemical solution on the peaty soil environment different experiments namely; shrinkage limit, unconfined compressive strength (UCS), pH test, and water content were undertaken. The results of the laboratory experiments are further proved and interpreted using the X-ray diffraction, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy tests. The result unveils the structure of the treated soil significantly changed depending upon the used additive type and concentrations. The rate of shrinkage largely decreased when sodium silicate additives are used. In addition, it was observed that UCS value increased up to 500% and water content reduced up to 50% in comparison with untreated samples, depend on the amount of used non-traditional additives. The SEM micrographs of the sample before and after treatment validate the results obtained and analyzed from experiments.  相似文献   

Diffracted ScS and the Shear Velocity at the Core Boundary     

Bruce A. Bolt  Mansour Niazi  M. R. Somerville 《Geophysical Journal International》1970,19(3):299-305

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Lithostratigraphy of Sheikh Shadli metavolcanics and the older metasediments in Um Samiuki district,eastern desert,Egypt     

N.M. Shukri  M.S. Mansour 《Precambrian Research》1978,6(1):A36-A37

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CAD-DRASTIC: chloride application density combined with DRASTIC for assessing groundwater vulnerability to road salt application     

Mansour Salek  Jana Levison  Beth Parker  Bahram Gharabaghi 《Hydrogeology Journal》2018,26(7):2379-2393

Road salt is pervasively used throughout Canada and in other cold regions during winter. For cities relying exclusively on groundwater, it is important to plan and minimize the application of salt accordingly to mitigate the adverse effects of high chloride concentrations in water supply aquifers. The use of geospatial data (road network, land use, Quaternary and bedrock geology, average annual recharge, water-table depth, soil distribution, topography) in the DRASTIC methodology provides an efficient way of distinguishing salt-vulnerable areas associated with groundwater supply wells, to aid in the implementation of appropriate management practices for road salt application in urban areas. This research presents a GIS-based methodology to accomplish a vulnerability analysis for 12 municipal water supply wells within the City of Guelph, Ontario, Canada. The chloride application density (CAD) value at each supply well is calculated and related to the measured groundwater chloride concentrations and further combined with soil media and aquifer vadose- and saturated-zone properties used in DRASTIC. This combined approach, CAD-DRASTIC, is more accurate than existing groundwater vulnerability mapping methods and can be used by municipalities and other water managers to further improve groundwater protection related to road salt application.  相似文献   

Aeromagnetic data interpretation of east Qattara Depression,Northwest Desert,Egypt     

Mansour A. Al-Garni 《Arabian Journal of Geosciences》2018,11(6):133

The study area is located at the east of Qattara Depression at the north of the Western Desert of Egypt. The study area contains Abu Gharadig basin, which is the most petroliferous basin in the Egyptian Western Desert. Only three exploratory wells are presented in the study area, showing a thick sediment section overlying basement rocks. Magnetic data have been frequently used in geophysical exploration. Aeromagnetic data are mainly utilized to estimate the depth to the magnetic basement as well as to delineate the possible structures of the study area. The depth to magnetic basement has been estimated using the analytical solution of exponential equations obtained from the Fourier transformation of magnetic data, assuming multi-prisms. The depths obtained from this technique vary from 0.70 to 2.91 km with an average depth of 2.08 km. Local phase filters have been mainly used as edges detector where the possible occurrences structures can be delineated. Hyperbolic tilt angle, second-order tilt angle, and normalized total horizontal derivative (TDX) provide the best results for delineating the possible structures, showing the possible contacts within the basement of the study area. The edge enhancement filters show that the study area has been affected by different structural trends taking E-W, NE-SW, NNE-SSW, N-S, and ENE-WSW directions.  相似文献   

Examination of multi-perturbation methods for ensemble prediction of the MJO during boreal summer     

In-Sik Kang  Pyong-Hwa Jang  Mansour Almazroui 《Climate Dynamics》2014,42(9-10):2627-2637

The impact of initialization and perturbation methods on the ensemble prediction of the boreal summer intraseasonal oscillation was investigated using 20-year hindcast predictions of a coupled general circulation model. The three perturbation methods used in the present study are the lagged-averaged forecast (LAF) method, the breeding method, and the empirical singular vector (ESV) method. Hindcast experiments were performed with a prediction interval of 10 days for extended boreal summer (May–October) seasons over a 20 year period. The empirical orthogonal function (EOF) eigenvectors of the initial perturbations depend on the individual perturbation method used. The leading EOF eigenvectors of the LAF perturbations exhibit large variances in the extratropics. Bred vectors with a breeding interval of 3 days represent the local unstable mode moving northward and eastward over the Indian and western Pacific region, and the leading EOF modes of the ESV perturbations represent planetary-scale eastward moving perturbations over the tropics. By combining the three perturbation methods, a multi-perturbation (MP) ensemble prediction system for the intraseasonal time scale was constructed, and the effectiveness of the MP prediction system for the Madden and Julian oscillation (MJO) prediction was examined in the present study. The MJO prediction skills of the individual perturbation methods are all similar; however, the MP‐based prediction has a higher level of correlation skill for predicting the real-time multivariate MJO indices compared to those of the other individual perturbation methods. The predictability of the intraseasonal oscillation is sensitive to the MJO amplitude and to the location of the dominant convective anomaly in the initial state. The improvement in the skill of the MP prediction system is more effective during periods of weak MJO activity.  相似文献   

Geophysical survey for geological hazards assessment of Wadi Thuwal area, KSA: a case history     

Mansour A. Al-Garni  Mohamed G. El-Behiry  Mohamed M. Gobashy 《Arabian Journal of Geosciences》2012,5(1):133-146

Magnetic and seismic methods have been used in this study as complementary methods to each other to construct a geologic hazard map for Wadi Thuwal area. Magnetic interpretation for deep-seated geologic structures has involved reduction to pole algorithm and downward continuation techniques. It showed that there are three major fault trends: NE-SW and NNE-SSW, NW-SE, and N-S. Furthermore, shear zone has been found close to Harrat Thuwal, which was confirmed by the seismic method. Seismic method revealed three lithologic layers where the depth of the bedrock was found to be ranging between 9?m at the southeastern part of the study area and 24?m at its northern part. It showed also five major fault trends: NW-SE, ENE-WSW, NE-SW, and nearly E-W. Supported by the surface geology, magnetic and seismic results showed that the Wadi Thuwal area can be divided into three zones on the basis of geologic hazards, depending on the presence of geologic features such as faults. It is recommended that before any development plan in Wadi Thuwal area, the delineated hazard zonation should be taken into account.  相似文献