Evidence of seismites in coastal Quaternary deposits of western Oranie (northwestern Algeria)     

Mohamed Amine Boukhedimi  Amina Louni-Hacini  Youcef Bouhadad  Jean-François Ritz  Djamel Machane  Azzeddine Benhamouche  Hamid Bourenane 《Journal of Seismology》2017,21(3):539-549

Coastal Quaternary deposits of western Oranie show typical soft-sediment deformations including sedimentary dykes, sand volcanoes, sismoslumps, thixotropic bowls, thixotropic wedges, diapir-like structures, and faults grading. Field observations indicate that these deformations exist at several levels of the studied deposits along the west Oranian coast. This study demonstrated that these structures are earthquakes-related, by analysis of potential trigger sources. Several arguments demonstrate the seismic origin: the depositional environment rich in water that located in an active tectonic region, the thixotropic nature of deformations and their large vertical and horizontal diffusion in the Quaternary series consistent with a seismic recurrence. This allows characterizing these Quaternary soft-sediment deformations as seismites that were triggered by earthquakes.  相似文献   

A practical approach for seismic risk assessment of underground structures: A case study of Iranian subway tunnels     

Arsham Moayedifar  Hamid Reza Nejati  Amin Nazerigivi  Mohammad Khosrotash 《地震科学（英文版）》2019,32(2):64-71

Active geological and young faulted zones have made Iran’s territory one of the most seismological active areas in the world according to recent historical earthquakes. Some of the deadliest earthquakes such as Gilan 1990 and Kermanshah 2018 caused tens of thousands fatalities. If such violent earthquakes affect strategical structures of a country, indirect losses would be more concerning than direct losses. Nowadays there is no doubt about the vital role of tunnels and underground structures in urban areas. These facilities serve as nonstop functional structures for human transportation, water and sewage systems and underground pedestrian ways. Any external hazard subjected to underground spaces, such as earthquake could directly affect passenger’s lives and significantly decrease whole system reliability of public transportation. Commonly two earthquake levels of intensities, Maximum Design Earthquake (MDE) and Operating Design Earthquake (ODE) were used in seismic design of underground structures. However, uncertain nature of earthquakes in terms of frequency content, duration of strong ground motion, and level of intensity indicate that only the two levels of earthquake (ODE and MDE) cannot cover the all range of possible seismic responses of structures during a probable earthquake. It is important to evaluate the behavior of tunnel under a wide range of earthquake intensities. For this purpose, a practical risk-based approach which is obtained using the total probability rule was used. This study illustrates a framework for evaluation seismic stability of tunnels. Urban railway tunnels of Tehran, Shiraz, Ahwaz, Mashhad, Isfahan and Tabriz were considered as study cases. Nominal value of seismic risk for three main damage states, including minor, moderate and major were calculated.  相似文献   

Special Issue: IAMG 2019     

Leung  Juliana Y.  Li  Liangping  Morgan  Eugene  Emami-Meybodi  Hamid 《Mathematical Geosciences》2020,52(8):975-976

Mathematical Geosciences -  相似文献   

Comparison of new individual and hybrid machine learning algorithms for modeling and mapping fire hazard: a supplementary analysis of fire hazard in different counties of Golestan Province in Iran     

Eskandari  Saeedeh  Amiri  Mahdis  Sãdhasivam  Nitheshnirmal  Pourghasemi  Hamid Reza 《Natural Hazards》2020,104(1):305-327

Natural Hazards - The forest fire hazard mapping using the accurate models in the fire-prone areas has particular importance to predict the future fire occurrence and allocate the resources for...  相似文献   

Analyse multi-échelle par ondelettes des contacts géologiques : application à la carte gravimétrique du Maroc nord-oriental     

Driss Khattach  Hamid Mraoui  Driss Sbibih  Touria Chennouf 《Comptes Rendus Geoscience》2006,338(8):521-526

The multiscale wavelet analysis has been applied to the gravity data from northeastern Morocco to map the major geological contacts, such us faults. Hence, the faults affecting the survey area were outlined with their importance level and dip direction. Seismic data confirm these results and testify the efficiency of this method, particularly in studying structure of plains. The structural map established is a very useful document in the planning of natural resources investigations (i.e. water, mines) to be undertaken in the area of study. To cite this article: D. Khattach et al., C. R. Geoscience 338 (2006).  相似文献   

Monitoring of dust storm and estimation of aerosol concentration in the Middle East using remotely sensed images     

Taheri Shahraiyni  Hamid  Karimi  Khadijeh  Habibi Nokhandan  Majid  Hafezi Moghadas  Naser 《Arabian Journal of Geosciences》2015,8(4):2095-2110

Arabian Journal of Geosciences - Dust storms are one of the major environmental disasters in the arid regions of Middle East, occurring in very high frequency. As a result, monitoring dust storms...  相似文献   

Application of analytical hierarchy process,frequency ratio,and certainty factor models for groundwater potential mapping using GIS   总被引：4，自引：1，他引：3  

Yousef Razandi  Hamid Reza Pourghasemi  Najmeh Samani Neisani  Omid Rahmati 《Earth Science Informatics》2015,8(4):867-883

  相似文献   

Snow water equivalent prediction using Bayesian data assimilation methods   总被引：1，自引：0，他引：1  

Marc Leisenring  Hamid Moradkhani 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(2):253-270

Using the U.S. National Weather Service’s SNOW-17 model, this study compares common sequential data assimilation methods, the ensemble Kalman filter (EnKF), the ensemble square root filter (EnSRF), and four variants of the particle filter (PF), to predict seasonal snow water equivalent (SWE) within a small watershed near Lake Tahoe, California. In addition to SWE estimation, the various data assimilation methods are used to estimate five of the most sensitive parameters of SNOW-17 by allowing them to evolve with the dynamical system. Unlike Kalman filters, particle filters do not require Gaussian assumptions for the posterior distribution of the state variables. However, the likelihood function used to scale particle weights is often assumed to be Gaussian. This study evaluates the use of an empirical cumulative distribution function (ECDF) based on the Kaplan–Meier survival probability method to compute particle weights. These weights are then used in different particle filter resampling schemes. Detailed analyses are conducted for synthetic and real data assimilation and an assessment of the procedures is made. The results suggest that the particle filter, especially the empirical likelihood variant, is superior to the ensemble Kalman filter based methods for predicting model states, as well as model parameters.  相似文献   

Timing of juvenile arc crust formation and evolution in the Sapat Complex (Kohistan–Pakistan)     

Pierre Bouilhol  Urs Schaltegger  Massimo Chiaradia  Maria Ovtcharova  Andreas Stracke  Jean-Pierre Burg  Hamid Dawood 《Chemical Geology》2011,280(3-4):243-256

The combination of age determination and geochemical tracers allows understanding the source evolution during magmatism. We studied the Sapat Complex, in the exhumed Cretaceous Kohistan Paleo-Island Arc, to reconstruct the formation of the juvenile lower arc crust and the evolution of the mantle source during arc magmatism. High precision ID-TIMS U/Pb dating on zircon, shows that a protracted period of magmatic accretion formed the Sapat Complex between 105 and 99 Ma. Since continued melt percolation processes that formed the lower crust obscured the original bulk rock Nd–Pb–Sr isotopic composition, we rely on the Hf isotopic composition of zircons of different ages to unravel the source evolution. Nd and Pb bulk isotopic compositions coupled with Hf isotopic composition on zircons allow reconstructing a geodynamical scenario for the Sapat Complex, and the Cretaceous history of the Arc. We suggest that trenchward migration of the hot mantle source at 105 Ma explains the small heterogeneous εHf signal between + 14 and + 16. This heterogeneity vanished within ca. 2 million years, and the εHf of the source evolved from + 16 to + 14 at 99 Ma. Integrated to the Kohistan Cretaceous history, which has a baseline of εHf ≈ 14, these data pinpoint two geodynamical events, with slab retreat and the formation of the Sapat Complex followed by splitting of the Kohistan island arc at 85 Ma.  相似文献   

Time evolution of nonplanar electron acoustic shock waves in a plasma with superthermal electrons     

Hamid Reza Pakzad  Kurosh Javidan  Mouloud Tribeche 《Astrophysics and Space Science》2014,352(1):185-191

The propagation of cylindrical and spherical electron acoustic (EA) shock waves in unmagnetized plasmas consisting of cold fluid electrons, hot electrons obeying a superthermal distribution and stationary ions, has been investigated. The standard reductive perturbation method (RPM) has been employed to derive the cylindrical/spherical Korteweg-de-Vries-Burger (KdVB) equation which governs the dynamics of the EA shock structures. The effects of nonplanar geometry, plasma kinematic viscosity and electron suprathermality on the temporal evolution of the cylindrical and spherical EA shock waves are numerically examined.  相似文献