Geospatial susceptibility mapping of earthquake-induced landslides in Nuweiba area,Gulf of Aqaba,Egypt

Earthquake induced landslides are one of the most severe geo-environmental hazards that cause enormous damage to infrastructure, property, and loss of life in Nuweiba area. This study developed a model for mapping the earthquake-induced landslide susceptibility in Nuweiba area in Egypt with considerations of geological, geomorphological, topographical, and seismological factors. An integrated approach of remote sensing and GIS technologies were applied for that target. Several data sources including Terra SAR-X and SPOT 5 satellite imagery, topographic maps, field data, and other geospatial resources were used to model landslide susceptibility. These data were used specifically to produce important thematic layers contributing to landslide occurrences in the region. A rating scheme was developed to assign ranks for the thematic layers and weights for their classes based on their contribution in landslide susceptibility. The ranks and weights were defined based on the knowledge from field survey and authors experiences related to the study area. The landslide susceptibility map delineates the hazard zones to three relative classes of susceptibility: high, moderate, and low. Therefore, the current approach provides a way to assess landslide hazards and serves for geo-hazard planning and prediction in Nuweiba area.     

Mineral processing characteristics of natural zeolites from the Aritayn Formation of northeast Jordan

The inferior grade of natural zeolite ores in comparison to their synthetic counterparts has been identified as a possible factor responsible for the relatively small market share of the former. This paper describes the results of laboratory-scale mineral processing trials carried out on relatively low-grade natural zeolite ores from the Aritayn Formation of northeast Jordan to improve their purity through removal of unwanted gangue constituents. Appropriate sample preparation and mineral processing methods were selected which utilised contrasts in texture, particle-size, hardness, specific gravity and magnetic susceptibility between gangue and target constituents to achieve beneficiation. Sample preparation by autogenous comminution was able to selectively liberate zeolite minerals from the surface of pyroclasts and therefore was an effective method of pre-concentration. Subsequently, using widely-available magnetic and gravity separation equipment, a high-grade concentrate containing 89% zeolite was produced at a recovery of 37% from a lapilli tuff of 47% head grade.     

Strain Analysis and Microstructural Investigation of the Jabal Tays Ophiolite Complex,Eastern Arabian Shield,Saudi Arabia

Geotectonics - The present study deals with the Jabal Tays ophiolite area, which was affected by Al Amar-Idsas fault. It is one of the most important tectonic features in the Eastern Arabian...     

Validation of the Meteosat Second Generation (MSG) fire monitoring product using ground observations over Turkey

Validation of the active fire monitoring (FIR) product from Spinning Enhanced Visible and Infrared Imager sensor of Meteosat Second Generation satellite is performed over Turkey. Ground truth data from the Ministry of Environment and Forestry for the years 2007, 2008, and 2009 is used by taking the active fire months of April–September into consideration. The contingency tables are obtained on a monthly basis and categorical statistics of probability of detection (POD) and false alarm rate (FAR) are derived. The results are introduced for each subclass, namely probable, possible, and combined cases. The highest POD amounts of 8.5, 1.93, and 9.4 % are obtained for the possible, probable, and combined cases, respectively, with the lowest FAR amounts of 70.9, 4.5, and 86.1 % for the same categories. FIR product validation with respect to predefined burnt area thresholds is introduced in the second part of the study in order to investigate burnt area effect in active fire detection. Increasing POD values with respect to burnt area amount is obtained with relatively higher values in probable than possible type. On the other hand, FAR variation is observed to be not correlated with the burnt area amount.     

The use of dinoflagellate cysts to separate human-induced from natural variability in the trophic state of the Po River discharge plume over the last two centuries

To obtain insight into the natural and/or human-induced changes in the trophic state of the distal portion of the Po River discharge plume over the last two centuries, high temporal resolution dinoflagellate cyst records were established at three sites. Cyst production rates appear to reflect the natural variability in the river's discharge, whereas cyst associations reflect the trophic state of the upper waters, which in turn can be related to agricultural development. The increased abundances of Lingulodinium machaerophorum and Stelladinium stellatum found as early as 1890 and 1920 correspond to the beginning of the industrial revolution in Italy and the first chemical production and dispersion of ammonia throughout Europe. After 1955, the increased abundances of these species and of Polykrikos schwartzii, Brigantedinium spp. and Pentapharsodinium dalei correspond to agriculturally induced alterations of the hypertrophic conditions. A slight improvement in water quality can be observed from 1987 onward.     

Start‐Up Study on Biohydrogen from Palm Oil Mill Effluent in a Pilot‐Scale Reactor

A start‐up study for biohydrogen production from palm oil mill effluent (POME) is carried out in a pilot‐scale up‐flow anaerobic sludge blanket fixed‐film reactor (UASFF). A substrate with a chemical oxygen demand (COD) of 30 g L^?1 is used, starting with molasses solution for 30 days and followed by a 10% v/v increment of POME/molasses ratio. At 100% POME, a hydrogen content of 80%, hydrogen production rate of 36 L H₂ per day, and maximum COD removal of 48.7% are achieved. Bio‐kinetic coefficients of Monod, first‐order, Grau second‐order, and Stover‐Kincannon kinetic models are calculated to describe the performance of the system. The steady‐state data with 100% POME shows that Monod and Stover‐Kincannon models with bio‐kinetic coefficients of half‐velocity constant (K_s) of 6000 mg COD L^?1, microbial decay rate (K_d) of 0.0015 per day, growth yield constant (Y) of 0.786 mg volatile suspended solids (VSS)/mg COD, specific biomass growth rate (μ_max) of 0.568 per day, and substrate consumption rate of (U_max) 3.98 g/L day could be considered as superior models with correlation coefficients (R²) of 0.918 and 0.989, respectively, compared to first‐order and Grau's second‐order models with coefficients of K₁ 1.08 per day, R² 0.739, and K_2s 1.69 per day, a = 7.0 per day, b = 0.847.     

Origin and variability of a terminal Proterozoic primary silica precipitate,Athel Silicilyte,South Oman Salt Basin,Sultanate of Oman

The Precambrian–Cambrian Athel Silicilyte is a 400 m thick, salt‐encased siliceous succession in the South Oman Salt Basin. It is a self‐sourcing hydrocarbon reservoir and comprises up to 95% microcrystalline quartz and exhibits wavy discontinuous lamination, comprising thin, alternating organic‐rich and silica‐rich layers. Textures and geochemical fingerprinting indicate that it is a primary precipitate formed by microbially mediated precipitation of silica from sea water, within the water column at the sulphidic/oxic interface. The unique occurrence of the Athel Silicilyte in the terminal Proterozoic implies that optimal conditions for this style of silica precipitation occurred only briefly. Basin anoxia, coupled with the growth of microbial mats, low pH and high silica pore water saturations, created optimal chemical conditions for silica precipitation. Volumes of microcrystalline quartz are highest within the transgressive and early highstand systems tract and towards the centre of the Athel Basin. At the basin margins, and within the late highstand systems tract, volumes of microcrystalline quartz decreased as the volume of detrital sediment increased. Mass‐balance calculations indicate that silica‐enriched sea water would have been supplied to the basin by infrequent marine incursions that replenished ambient sea water in the upper part of the water column. In conclusion, precipitation of the Athel Silicilyte was driven by the coincidence of basin restriction, limited clastic input, availability of organic matter and water column anoxia. The observation that there are few documented examples of chert deposits younger than ca 700 Ma, prior to the Cambrian explosion, suggests that although silica budgets within marine basins probably remained high prior to the evolution of silica‐secreting organisms, direct precipitation from sea water was restricted. This is tentatively related to the gradual increase in alkalinity of sea water through the Palaeo‐Proterozoic and Meso‐Proterozoic, such that silica precipitation could only occur through the coincidence of basin anoxia and low siliciclastic input.     

Opaque mineralogy and magnetic investigation of some basaltic occurrences, Sinai, Egypt

Ore microscopic investigation of the Fe?CTi oxide minerals was carried out on samples from three Oligo-Miocene basaltic occurrences from Sinai, Egypt. These occurrences are Gebel Maghara (north Sinai), Rageibet Naama (central Sinai), and Wadi Matulla (west Sinai). The results and correlations of magnetic parameters such as NRM intensity and susceptibility, coercive force H _c, and the ratio M _r/M _s, H _c and Q value, the ratio M _r/M _s, saturation magnetization M _s, and K are discussed in light of opaque mineralogical studies. It has been found that the variations in the magnetic properties of the basaltic occurrences are strongly dependent on the crystallite size and nature and style of exsolution textures and fabrics. The latter are controlled by the cooling conditions, being most sensitive to the partial pressure of oxygen in the melt.     

Effect of soil hydraulic properties model on slope stability analysis based on strength reduction method

Soil hydraulic properties models which have been proposed were derived based on the empirical fitting curve such as Brooks-Corey model (BC) and Van Genuchten model (VG), or based on soil pore radius distribution such as Lognormal model (LN). Each model has different accuracy for predicting soil moisture distribution. In the analysis of rainfall-induced slope failure, the soil hydraulic properties model was needed to describe the physical phenomena of behavior characteristic of water in unsaturated soil. As moisture content has an effect on soil strength, it is vital to select the suitable soil hydraulic properties model for predicting Factor of Safety (FOS) especially in forecasting landslide hazard. In this study, a numerical model of seepage finite element analysis using BC, VG, and LN model were used and compared in order to analyze the soil moisture distribution, water movement phenomenon, and slope stability characteristic in unsaturated soil slope based on the strength reduction method (SRM). The results showed that the variations of the parameters predicting the moisture content of soil leads to differences of FOS in some cases. The parametric study showed that for the unsaturated soil condition, BC model has the greatest FOS value than the other model, while VG model has the lowest. On the other hand, the FOS of all models have the same result for the saturated condition. Other than that, it was found that the increasing of ESP value in the surface layer has significant effect in the sub-surface layer.     

Analytical solutions for one-dimensional advection–dispersion equation of the pollutant concentration

We present simple analytical solutions for the unsteady advection–dispersion equations describing the pollutant concentration C(x, t) in one dimension. The solutions are obtained by using Laplace transformation technique. In this study we divided the river into two regions x ≤ 0 and x≥0 and the origin at x = 0. The variation of C(x, t) with the time t from t = 0 up to t → ∞ (the steady state case) is taken into account in our study. The special case for which the dispersion coefficient D = 0 is studied in detail. The parameters controlling the pollutant concentration along the river are determined.