Evaluation of earthquake activity along the Serghaya fault, Syria, from instrumental seismic data

This is a tentative study in order to characterize and identify the Serghaya fault in Syria through an analysis of its instrumentally observed earthquake activity for the period of 1995–2009. Different approaches are used to evaluate a- and b-values of the Gutenberg-Richter relation. It has been found that the computed b-values (around 1.5) are bigger than usually expected, which could be related either to incompleteness of earthquake catalogue or to invalidity of the Gutenberg-Richter model in the case of Serghaya fault. Based on several explanations of high b-values, existing in the literature, it can be inferred that the events recorded on the Serghaya fault occurred at small depths in the heterogeneous milieus under low stresses. A relative seismic quiescence from 1900 up to now is observed, whereas the biggest earthquake recorded during the study period does not exceed magnitude 3.9. Such quiescence does not reflect accurately an earthquake potential of the Serghaya fault and can probably indicate a large-magnitude earthquake occurrence in near future. The established earthquake catalogue must be necessarily completed in order to deeper characterize the real behavior of the Serghaya fault. Such a characterization, accompanied with seismic activity evaluation, could be used in the assessment of seismic hazard.     

Groundwater potential estimation using vertical electrical sounding measurements in the semi-arid Khanasser Valley region,Syria

Abstract

Traditional and polar vertical electrical sounding (VES) techniques were used for computing and characterizing the transmissivity of the Quaternary and Palaeogene aquifers in the Khanasser Valley, northern Syria. The VES technique with its different applied approaches is inexpensive, easy and gives rapid results with high spatial resolution. The Dar-Zarrouk parameters were determined to estimate the groundwater potential of the aquifers. The results show the mean transmissivity of the Quaternary aquifer to be 49 m²/d (minimum: 10 m²/d; maximum: 131 m²/d; standard deviation: 32 m²/d), and that of the Palaeogene aquifer is 0.94 m²/d (minimum: 0.31 m²/d; maximum: 1.54 m²/d; standard deviation: 0.33 m²/d).

Editor D. Koutsoyiannis

Citation Asfahani, J., 2013. Groundwater potential estimation using vertical electrical sounding measurements in the semi-arid Khanasser Valley region, Syria. Hydrological Sciences Journal, 58 (2), 468--482.     

Removal of the Alphazurine FG Dye from Simulated Solution by Electrocoagulation

The removal of Alphazurine FG (AF) dye from water by an electrocoagulation process has been studied. The effect of some operational parameters, such as anode material, current density, initial dye concentration, pH of solution, conductivity, and inter‐electrode distance, on the removal efficiency was investigated. Iron and aluminum were used as anodes in the electrocoagulation cell. It was found that the efficiency of the iron anode was better than that of the aluminum anode for AF removal. The factors that affected the removal efficiency were the current density and the initial dye concentration. The removal efficiency increased from about 35% at 25 A m^–2 to about 97% at 100 A m^–2, during 4 min of electrocoagulation. The results exhibited pseudo‐first‐order kinetics for AF removal by electrocoagulation. In addition, a mathematical model was successfully established for predicting the removal efficiency. A comparison between the model results and experimental data gave a high correlation coefficient (R² = 0.9925), which indicates that the model is able to predict the removal efficiency of AF.     

Quaternary aquifer transmissivity derived from vertical electrical sounding measurements in the semi-arid Khanasser Valley Region,Syria

Vertical electrical sounding technique (VES) is used as an alternative approach to pumping test for computing the Quaternary aquifer transmissivity in the Khanasser Valley, Northern Syria. The method is inexpensive, easy and gives faster results with higher special resolution than the traditional pumping technique. The hydraulic conductivity values obtained using VES agree with the pumping test results, which in the Khanasser Valley vary between the order of 0.864 and 8.64 m/day (10⁻⁵ and 10⁻⁴ m/s). The probable location of the Quaternary aquifer in the Khanasser Valley is obtained through the transmissivity map derived from VES. The knowledge of transmissivity is fundamental for modeling and management processes in the Khanasser Valley. Other similar semiarid regions can benefit from the approach successfully applied in the study area.     

Seismic behavior of steel buildings with out‐of‐plumb

A structure that has a permanent offset from a true vertical line is commonly referred to as being ‘out‐of‐plumb’. Out‐of‐plumb may result from construction tolerances or post‐earthquake permanent deformations in steel buildings. This paper quantifies the displacements of buildings with out‐of‐plumb in subsequent seismic events by means of inelastic dynamic time history analysis. Structures considered have different structural heights, force design reduction factors (R), and target inter‐story drifts. It is shown that buildings with greater out of plumb and force design reduction factor have larger normalized peak inter‐story drift ratio and ratio of residual‐to‐peak drift. Also, the ratio of residual‐to‐peak drift was not strongly dependent on structural height or design drift. A design procedure and example provided, based on the results obtained, show how peak and residual inter‐story drift ratio can be estimated. Copyright © 2015 John Wiley & Sons, Ltd.     

Remote Sensing of Mangrove Change Along the Tanzania Coast

This article contributes to the understanding of the changes in distribution and total area of mangrove forests along the mainland Tanzania coast over the past decade. Mangroves are recognized as critical coastal habitat requiring protection and special attention. The Tanzania coastline forms a suitable habitat for establishment of mangrove forests. Mangrove forests are distributed from Tanga in the north to Mtwara in the south covering approximately 109,593 hectares from 1988-1990 and about 108,138 hectares in 2000. The largest continuous mangrove stands are found in the districts of Rufiji, Kilwa, Tanga-Muheza, and Mtwara. Comparison of data between these two time periods shows that the geographic coverage of mangroves has no dramatic change in the past decade. The Tanzania Mangrove Management Project and other closely related programs and efforts pertaining to mangrove conservation contribute to direct restoration and natural regeneration of mangroves. This study documents the changes of mangroves and demonstrates that remote sensing and GIS offer important data and tools in the advancement of coastal resource management and ecosystem monitoring. Application of geographic information technologies is critical for improved coastal resources management and decision making for sustainable development in Tanzania.     

Early Cretaceous exhumation of high‐pressure metamorphic rocks of the Sistan Suture Zone,eastern Iran

The Sistan Suture Zone (SSZ) of eastern Iran is part of the Neo‐Tethyan orogenic system and formed by convergence of the Central Iranian and Afghan microcontinents. Ar Ar ages of ca. 125 Ma have been obtained from white micas and amphibole from variably overprinted high‐pressure metabasites within the Ratuk Complex of the SSZ. The metabasites, which occur as fault‐bounded lenses within a subduction mélange, document peak‐metamorphic conditions in eclogite or blueschist facies followed by near‐isothermal decompression resulting in an epidote–amphibolite‐facies overprint. ⁴⁰Ar/³⁹Ar step heating experiments were performed on a phengite + paragonite mixture from an eclogite, phengites from two amphibolites, and paragonite from a blueschist; ‘best‐fit’ ages from these micas are, respectively, 122.8 ± 2.2, 124 ± 13, 116 ± 19 and 139 ± 19 Ma (2σ error). Barroisite from an amphibolite yielded an age of 124 ± 10 Ma. The ages are interpreted as cooling ages that record the post‐epidote–amphibolite stage in the exhumation of the rocks. Our results imply that both the high‐pressure metamorphism and the epidote–amphibolite‐facies overprint occurred prior to 125 Ma. Subduction of oceanic lithosphere along the eastern margin of the Sistan Ocean had therefore begun by Barremian (Early Cretaceous) times. Copyright © 2008 John Wiley & Sons, Ltd.     

High-throughput production of peroxidase and its biodegradation potential toward polymeric material

Plastics are polymeric materials, and their disposal is a great problem in today’s society. Large quantities of single-use plastics are used every minute throughout the world. Peroxidase enzymes play a significant role in the biodegradation of polymeric materials due to oxidoreductase capability. The objective is to determine which set of conditions optimize the production of peroxidase enzymes by Phanerochaete chrysosporium so as to degrade polymeric materials. The sequential order of parameters in terms of their relevant performance in the bioprocess was determined as urea > polyvinyl chloride > incubation time > polyethylene > veratryl alcohol > sucrose > ammonium sulfate > glucose > ferrous sulfate and polystyrene. Statistical analysis was performed by using analysis of variance which indicated the significance of model Plackett–Burman and components on the basis of F value and P value of 0.012678 < 0.05. The Fourier transform infrared spectroscopy of enzyme-treated polymer revealed structural changes at 1091, 1638 cm^?1. A new peak appeared at wave number 1029 and represented the aromatic ether and phenolic group as compared to control. Biosynthesis of lignin peroxidase at optimized conditions has the potential for biodegradation of recalcitrant polymeric waste, due to its oxidoreductase capability for chemically inert material in nature like lignin and can be used for waste treatment on a large scale.     

A new developed approach for the prediction of ground vibration using a hybrid PSO-optimized ANFIS-based model

Ground vibration is one of the common environmental effects of blasting operation in mining industry, and it may cause damage to the nearby structures and the surrounding residents. So, precise estimation of blast-produced ground vibration is necessary to identify blast-safety area and also to minimize environmental effects. In this research, a hybrid of adaptive neuro-fuzzy inference system (ANFIS) optimized by particle swarm optimization (PSO) was proposed to predict blast-produced ground vibration in Pengerang granite quarry, Malaysia. For this goal, 81 blasting were investigated, and the values of peak particle velocity, distance from the blast-face and maximum charge per delay were precisely measured. To demonstrate the performance of the hybrid PSO–ANFIS, ANFIS, and United States Bureau of Mines empirical models were also developed. Comparison of the predictive models was demonstrated that the PSO–ANFIS model [with root-mean-square error (RMSE) 0.48 and coefficient of determination (R ²) of 0.984] performed better than the ANFIS with RMSE of?1.61 and R ² of 0.965. The mentioned results prove the superiority of the newly developed PSO–ANFIS model in estimating blast-produced ground vibrations.     

Estimating maximum magnitude earthquakes in Iraq using extreme value statistics

Summary. Extreme value theory is used to estimate maximum magnitude earthquakes in Iraq (29–38°N, 39–48°E). The seismicity file for the period 1905–1982 is used to determine the recurrence relationship as well as the parameters of Gumbel types I and III asymptotic distributions.
The statistical parameters are estimated by both least squares and maximum likelihood techniques. Results show that although the least squares upper magnitude is closer in value to actual earthquake magnitude, the maximum likelihood approximation to the third distribution appears to show a better overall fit to the data sample. This result is reflected in the calculated probability of occurrence of earthquake risk over various design periods.