An evaluation of earthquake hazard parameters in the Iranian Plateau based on the Gumbel III distribution

The Gumbel’s third asymptotic distribution (GIII) of the extreme value method is employed to evaluate the earthquake hazard parameters in the Iranian Plateau. This research quantifies spatial mapping of earthquake hazard parameters like annual and 100-year mode beside their 90 % probability of not being exceeded (NBE) in the Iranian Plateau. Therefore, we used a homogeneous and complete earthquake catalogue during the period 1900–2013 with magnitude M _w ? ≥?4.0, and the Iranian Plateau is separated into equal area mesh of 1° late?×?1° long. The estimated result of annual mode with 90 % probability of NBE is expected to exceed the values of M _w 6.0 in the Eastern part of Makran, most parts of Central and East Iran, Kopeh Dagh, Alborz, Azerbaijan, and SE Zagros. The 100-year mode with 90 % probability of NBE is expected to overpass the value of M _w 7.0 in the Eastern part of Makran, Central and East Iran, Alborz, Kopeh Dagh, and Azerbaijan. The spatial distribution of 100-year mode with 90 % probability of NBE uncovers the high values of earthquake hazard parameters which are frequently connected with the main tectonic regimes of the studied area. It appears that there is a close communication among the seismicity and the tectonics of the region.     

Crowdsourced approaches for stage measurements at ungauged locations using smartphones

ABSTRACT

The growing availability of smart devices with advanced sensors has increased the opportunities for citizen science applications for environmental monitoring. Accurate and widespread monitoring of river stage is vital for modeling water resources. Reliable data points are required for model calibration and validation in forecast studies. While current embedded monitoring systems provide accurate measurements, the cost to replicate these systems on a large domain is prohibitively expensive, limiting the quantity of data available. This project describes a new method to accurately measure river levels using smartphone sensors. Pictures of the same point on the river’s surface are taken to perform calculations based on the GPS location and spatial orientation of the smartphone. The proposed implementation is significantly more accessible than existing water measuring systems while offering similar accuracy. A case study is performed to evaluate the accuracy and sensitivity of the measurements to changes in distance.     

Levels of Organochlorine Pesticide Residues in Some Organs of the Ganges Perch, Lates calcarifer, from the Ganges–Brahmaputra–Meghna Estuary, Bangladesh

Levels of organochlorine pesticide residues (p,p′ DDT, DDD, DDE, Aldrin, Dieldrin, Lindane, Heptachlor and BHC) were analysed in the dry and wet seasons in four organs (muscle, liver, gut and egg samples) of Ganges Perch, Lates calcarifer, collected during October–November–December, 1996 and May–June–July, 1997 from the Ganges–Brahmaputtra–Meghna estuary. The residues were analysed by using gas-chromatography (GC) in electron capture detector (ECD) mode and were verified by thin layer chromatography (TLC). Among the four organs analysed, the residues were found in the order egg > gut > muscle > liver. The pesticide residues were found in the order ∑DDT > Heptachlor >Dieldrin > Aldrin. Higher levels of residues were found during the dry season due to high lipid content in fishes. A positive correlation was observed between the pesticide residues (∑DDT and ∑OCs) and lipid contents of fish, and the correlation was found to be linear. The concentrations of pesticide residues in muscle, liver and gut were below the FAO/WHO (1993) recommended permissible limit except in eggs.     

Fractionation and risk assessment of heavy metals in soil samples collected along Zerqa River,Jordan

The objectives of the current study were to determine the chemical partitioning of Pb, Ni, Zn, Co, Cr, Mn, Fe and Cd using sequential extraction procedure and to assess the environmental risk associated with these metals in the farming soils along Zerqa River. Metal concentrations were measured by atomic absorption spectrophotometer. The study area demonstrated a wide range for pH, organic matter, carbonate contents, and cation exchange capacity, and is polluted with Pb, Cd, Mn, and Cu. The extensive use of fertilizers and pesticides in the agricultural activities, and discharge of treated and untreated wastewater are the major sources of pollution in the study area. Principal component analysis coupled with Pearson’s correlation analysis between the heavy metals revealed strong and positive correlation between these metals in the study area. According to the Risk Assessment Code (RAC), major portions of Cd and Mn are contained in exchangeable and carbonates fractions and therefore can easily enter the food chain. These metals pose a high to very high risk to the environment. Cu, Ni, Pb, and Zn pose medium risk, while Cr poses a low environment risk.     

Linear genetic programming to scour below submerged pipeline

Genetic programming (GP) has nowadays attracted the attention of researchers in the prediction of hydraulic data. This study presents Linear Genetic Programming (LGP), which is an extension to GP, as an alternative tool in the prediction of scour depth below a pipeline. The data sets of laboratory measurements were collected from published literature and were used to develop LGP models. The proposed LGP models were compared with adaptive neuro-fuzzy inference system (ANFIS) model results. The predictions of LGP were observed to be in good agreement with measured data, and quite better than ANFIS and regression-based equation of scour depth at submerged pipeline.     

Seasonal changes of water properties and current in the northernmost gulf of aqaba,red sea

Seasonal changes of tide signal(s), temperature, salinity and current were studied during the years 2004-2005 in the northernmost Gulf of Aqaba, which is under developmental activities, to obtain scientific bases for best management and sustainability. Spectrum analysis revealed permanent signals of tide measurements during all seasons, which represented semidiurnal and diurnal barotropic tides. The other signal periods of 8.13, 6.10-6.32, 4.16 and 1.02-1.05 h were not detected in all seasons, which were related to shallow water compound and overtides of principle solar and lunar constituent and to seiches generated in the Red Sea and the Gulf of Aqaba. Spatial and temporal distribution of temperature, salinity and density showed significant differences between months in the coastal and offshore region and no significant differences among the coastal sites, between the surface and bottom waters and between coastal and offshore waters. Therefore, the temporal and spatial variation of water properties in the northernmost Gulf of Aqaba behave similarly compared to other parts. The coastal current below 12 m depth was weak (3-6 cms^-1) and fluctuated from east-northeastward to west-southwestward (parallel to the shoreline), which may be related to the effect of bottom topography and/or current density due to differential cooling between eastern and western parts in the study area, and windinduced upwelling and downwelling in the eastern and western side, respectively. The prevailing northerly winds and stratification conditions during summer were the main causes of the southward current at 6 and 12 m depths with average speed of 28 and 12 cms^-1, respectively.     

Crustal Seismicity In and Around Turkey

Vertical and horizontal variations of the frequency of crustal earthquakes (h ≤ 35 km) that have occurred in and around Turkey are analyzed, using data from the Global Hypocenter Data Base and the IRIS data for the period 1964–1998. Fits of various magnitude scales to the observations have been used to construct a homogeneous catalogue. Depth distribution of the parameters derived from the Gutenberg–Richter relationship reveals that there is a depth dependence in the a- and b-values of the frequency distribution. It is observed that unknown focal depths (0, 10, 33 km) are dominant in the total seismicity reported, and give rise to substantial changes to the vertical distribution of these parameters. It is also observed that the parameters of either a or b alone may not be used as a measure of regional seismicity of the study area in which high and low seismic activity observed over short distances. In contrast, distribution of modal (a/b) values provides detailed images of the local areas presented by high and low seismic zones. This study presents evidence that low b-values are associated with major strike-slip faults, particularly exhibiting high apparent stresses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Finger prints of the formation of geothermal springs on the granitoids: Beypazarı–Ankara, Turkey

The Beypazarı granitoid in central Anatolia was emplaced during the Late Cretaceous and it is partly covered with Early Miocene–Quaternary sedimentary and volcanic units. Compression and tension regimes of the Beypazarı granitoid emplacing along the Sakarya River were evaluated considering the kinematical characteristics of discontinuities on granitoids, petrographic/geochemical works, formation of geothermal spring and irregularities in topographic structure. It was determined that the Beypazarı granitoid was witnessed with NE–SW compressional stress and NW–SE extensional stress which resulted in the formation of the Kapullu normal fault with N55–72°E, 78°SE crossing the Kapullu spring site. There are also several other probable normal faults around this fault in the Sakarya River basin. The results of the geochemical studies reveal that SiO₂, Na₂O, Al₂O_3, CaO and K₂O as a major oxide and As, Rb, Sr, Th and U as trace elements are decreased away from the Kapullu bath spring. On the other hand, the ratio of Fe₂O₃ and MgO as major oxide and Y as a trace element with the lost on ignition (LOI) are increased away from the Kapullu fault. Regard as the regional plate tectonism, there is a consistency between the direction of compression in the Beypazarı granitoid and that developed by the southwesterly movement of the Anatolian plate.     

Spatial prediction of landslide susceptibility in western Serbia using hybrid support vector regression (SVR) with GWO,BAT and COA algorithms

In this study, we developed multiple hybrid machine-learning models to address parameter optimization limitations and enhance the spatial prediction of landslide susceptibility models. We created a geographic information system database, and our analysis results were used to prepare a landslide inventory map containing 359 landslide events identified from Google Earth, aerial photographs, and other validated sources. A support vector regression (SVR) machine-learning model was used to divide the landslide inventory into training (70%) and testing (30%) datasets. The landslide susceptibility map was produced using 14 causative factors. We applied the established gray wolf optimization (GWO) algorithm, bat algorithm (BA), and cuckoo optimization algorithm (COA) to fine-tune the parameters of the SVR model to improve its predictive accuracy. The resultant hybrid models, SVR-GWO, SVR-BA, and SVR-COA, were validated in terms of the area under curve (AUC) and root mean square error (RMSE). The AUC values for the SVR-GWO (0.733), SVR-BA (0.724), and SVR-COA (0.738) models indicate their good prediction rates for landslide susceptibility modeling. SVR-COA had the greatest accuracy, with an RMSE of 0.21687, and SVR-BA had the least accuracy, with an RMSE of 0.23046. The three optimized hybrid models outperformed the SVR model (AUC = 0.704, RMSE = 0.26689), confirming the ability of metaheuristic algorithms to improve model performance.     

A new approximation in determination of zonation boundaries of ignimbrite by ground penetrating radar: Kayseri,Central Anatolia,Turkey

Ground penetrating radar (GPR) method is used as a tool to identify the zonation boundaries in ignimbrite series through their columnar section. Ignimbrites can be classified in terms of welding degree, colour, texture and mineralogical compositions. The research area comprises a part of İncesu (Kayseri) ignimbrite at Central Anatolia, Turkey. This ignimbrite is divided into three levels and each level has clear differences in terms of macroscopic and microscopic views. This paper presents the results of an application of GPR for the determination of zonation boundary within the ignimbrite flow unit in the view of their textural and petrological features. RAMAC CU II equipment was used with 250 MHz shielded antenna on parallel ten profiles to observe the physical difference among the ignimbrite levels of the study area. Two levels out of three have been defined at the İncesu ignimbrite and supported by field geology and petrographical studies. The first level, which is extremely fractured structure, is about 1.5 m thick and matches with middle level of the İncesu ignimbrite. The second level has an average 50–75 cm thickness and matches with lower level of the ignimbrite. In this manner, vertical lithological variations should be taken into consideration during petrological investigation of the ignimbrites.