Seismic risk assessment of the 3rd Azerbaijan gas pipeline in Iran

A comprehensive seismic risk assessment has been performed for the existing route of the 3rd Azerbaijan natural gas buried pipeline in Iran. The major active seismic sources along the pipeline were identified and the geometrical parameters as well as the seismicity rates were determined. The seismic hazard assessment of the ground vibrations along the pipeline was performed in the framework of the Probabilistic Seismic Hazard Analysis using the CRISIS 2007 software. All of the components of the gas pipeline along the route were identified and the corresponding fragility functions are established through the methodology described in the HAZUS guideline (HAZUS MH MR4 Technical manual 2007 Department of homeland security emergency. Preparedness and Response Directorate, FEMA). A detailed cost analyses was taken into consideration based on the expert opinions in the National Iranian Gas Company, in order to provide more practical loss model for the pipeline route. Also, a simple method is suggested in order to account for the vent gas in the total loss estimation. The spatial analysis of the hazard function layer in combination with the loss model layer, in Geographical Information System  (GIS) platform, reveal the financial consequences of different earthquake scenarios.     

The permeability of fault zones: a case study of the Dead Sea rift (Middle East)

Fault zone architecture plays an important role in flow regimes of hydrological systems. Fault zones can act as conduits, barriers, or conduits/barrier systems depending on their spatial architecture. The goal of this study is to determine the fault-zone permeability structure and its effect on the local hydrogeological system in the Dead Sea fault system. Permeability was measured on small-scale outcrop plug samples at four faults along the Dead Sea fault system, and large-scale slug tests in four boreholes, in different parts of the fault, at Yair fault in Israel. The research results show that values in the damage zone are two to five orders of magnitude higher than those of the fault core (~3.5?×?10^?10, 1?×?10^?15 m² respectively), resulting in an anisotropic permeability structure for the overall fault zone and preferable flow parallel to the fault. A set of injection tests in the Yair fault damage zone revealed a water-pressure-dependent behavior. The permeability of this zone increases when employing a higher water pressure in the fault fracture-dominated damage zone, due to the reopening of fractures.     

The effect of pH and salty solutions on durability of sandstones of the Aghajari Formation in Khouzestan province,southwest of Iran

Slake durability of rocks is a vital engineering geological property of rock materials that has an important role in the promotion of slope stability, evaluation of rock materials, as well as the estimation of stone degradability. This parameter is related to such factors as mineralogy, physical characteristics of rocks, and the environmental conditions. A major part of south and southwestern Iran embraces the Aghajari Formation whose sandstones are used to form the foundations for some structures in Khouzestan province where they are being extensively used as aggregate(s). In this paper, tests of mineralogical examinations, physical properties, and slake durability of sandstones from Ahwaz and Haftkel anticlines were administered in order to assess the durability and degradability of these rocks. The rock durability of each type was evaluated to be up to 15 cycles in acidic and alkaline watery environments and salt aqueous solutions. The results showed that durability of sandstones under study is related to their petrographical and physical characteristics. The durability index of the sandstone samples was decreased by pH reduction and by increasing the concentration of aqueous solutions. The durability index of Ahwaz samples, too, was decreased in basic solutions while this index increased for Haftkel sandstones with the increase in the pH of solutions. Also, the obtained results illustrated that durability index decreased with the increase in the number of cycles. Based on the results, all sandstones show that the durability in sodium sulfate solution is much lower than that for the sodium chloride. Moreover, the slake durability index of the sandstones is decreased with an increase in the concentration of aqueous solutions. As a final statement, the Ahwaz sandstones show lower resistance to weathering processes than Haftkel sandstones; therefore, the use of rocks as building stones is not recommended here.     

Barnacle fouling in the Mediterranean sponges Axinella polypoides and Axinella verrucosa

Secondary metabolites protect many marine sponges (Phylum: Porifera) from settlement by fouling organisms. Previous studies on the subtidal demosponge Axinella verrucosa collected in the Western Mediterranean led to the isolation of compounds that inhibited the settlement of cyprids larvae of the intertidal barnacle Balanus amphitrite, and the enzyme chitinase, which plays a key role in the molting cycle of crustaceans. However, in a field survey conducted at three locations in Israel, Eastern Mediterranean Sea, we observed that A. verrucosa is fouled by the subtidal barnacle Balanus trigonus, a previously unknown association. Settlement inhibition assays using B. amphitrite with chemical extracts from Israeli A. verrucosa and Axinella polypoides, a sympatric, congeneric sponge that seems not to be fouled by B. trigonus, showed that cyprid larvae of B. amphitrite were inhibited by the extracts of both sponges from settlement at concentrations several magnitudes lower than natural volumetric extract concentration in the sponges. These results indicate that, unlike the intertidal barnacle B. amphitrite, the subtidal B. trigonus is unaffected by the compounds from A. verrucosa, stressing and underlining the importance of using suitable target organisms (i.e. from the same habitat) to test for ecologically relevant antifouling activities.     

The nonlinear association between the Arctic Oscillation and North American winter climate

Nonlinear projections of the Arctic Oscillation (AO) index onto North American winter (December–March) 500-mb geopotential height (Z500) and surface air temperature (SAT) anomalies reveal a pronounced asymmetry in the atmospheric patterns associated with positive and negative phases of the AO. In a linear view, the Z500 anomaly field associated with positive AO resembles a positive North Atlantic Oscillation pattern with statistically significant positive and negative anomalies stretching zonally into central-eastern USA and Canada, respectively, resulting in a cold climate anomaly over northeastern and eastern Canada, Alaska and the west coast of USA, and a warm climate anomaly over the rest of the continent. By contrast, the nonlinear behavior, mainly a quadratic association with AO, which is most apparent when the amplitude of the AO index is large, has the same spatial pattern and sign for both positive and negative values of the index. The nonlinear pattern reveals negative Z500 anomalies over the west coast of USA and the North Atlantic and positive Z500 anomalies at higher latitudes centered over the Gulf of Alaska and northeastern Canada accompanied by cooler than normal climate over the USA and southwestern Canada and warmer than normal climate over other regions of the continent. A similar analysis is conducted on the data from the Canadian Center for Climate Modelling and Analysis second generation coupled general circulation model. The nonlinear patterns of North American Z500 and SAT anomalies associated with the AO in the model simulation are generally consistent with the observational results, thereby confirming the robustness of the nonlinear behavior of North American winter climate with respect to the AO in a climate simulation that is completely independent of the observations.     

Investigation of elemental enrichment and ecological risk assessment of surface soils in two industrial port cities,southwest Iran

In recent years, there has been a rapid growth in the two industrial port cities of Iran, the port of Mahshahr and the port of Imam Khomeini. In spite of their importance for the economy, the two cities require monitoring and assessment from an environmental and human health perspective. In this study, environmental quality and heavy metals pollution of soils influenced by human activities were investigated. A total of 30 soil samples were collected and subjected to detail physicochemical characterization. The results showed high levels of heavy metals in the urban soils of port of Mahshahr (POM) and elevated respective levels in surface soils of the port of Imam Khomeini (PIK) with Ni being significantly higher than those in POM. The integrated pollution index (IPI) values of metals ranged from 1.22 to 1.87 in POM and 1.52 to 3.31in PIK, 50% of soil samples in PIK were classified as highly polluted, and all of the soil samples in PM were classified as moderately polluted. These results are in accordance with Enrichment Factor (EF) values, which showed the role of anthropogenic activities in the soil heavy metal enrichment. Moreover, the highest potential ecological risk index (RI) was found in the sites of petrochemical industries in PIK indicating serious metal contamination. Statistical analysis showed that heavy metals were mainly controlled by human activities. The results showed more dense industrial activity in PIK is responsible for higher pollution. This study establishes a benchmark against which future monitoring and remediation programs can be based on. Because of proximity to the Persian Gulf, continued the release of contaminants into the region, could have adverse biological health effects.