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251.
The March 11, 2002 Masafi, United Arab Emirates earthquake: Insights into the seismotectonics of the northern Oman Mountains 总被引:2,自引:1,他引:1
Arthur Rodgers Abdel-Rahman Fowler Abdullah M.S. Al-Amri Abdullah Al-Enezi 《Tectonophysics》2006,415(1-4):57-64
A moderate (M 5) earthquake struck the northeastern United Arab Emirates (UAE) and northern Oman on March 11, 2002. The event was felt over a wide area of the northern Emirates and was accompanied by smaller (felt) events before and after the March 11 main shock. The event was large enough to be detected and located by global networks at teleseismic distances. We estimated focal mechanism and depth from broadband complete regional waveform modeling. We report a normal mechanism with a slight right-lateral strike-slip component consistent with the large-scale tectonics. The normal component suggests relaxation of obducted crust of the Semail ophiolite (specifically, the Khor Fakkan Block) while the right-lateral strike-slip component of the mechanism is consistent with shear across the Oman Line. Felt earthquakes are rare in the region, however no regional seismic network exists in the UAE to determine local seismicity. This event offers a unique opportunity to study the active tectonics of the region as well as inform future studies of seismic hazard in the UAE and northern Oman. 相似文献
252.
Syed Bilawal Ali Shah Wan Hasiah Abdullah 《Journal of the Geological Society of India》2017,90(3):323-328
The Balkassar oil field is situated in the eastern Potwar sub-basin, lies on the southern flank of Soan syncline in Himalayan collisional regime. The area represents Indo-Pak and Eurasian blocks of Precambrian to recent time. Thrusting and folding of Himalayan, Indo-Pak plate movement and Salt Range uplift form the structural trap in Balkassar sub-surface (Balkassar anticline). On the basis of information from eleven seismic 2D lines and wells data six reflectors well data, four faults were identified and marked. The structural trend is northeast southwest. Interpretation of seismic 2D data reveals that the study area has undergone intense deformation as a consequence of development of thrusts and backthrusts.The Balkassar anticline is bounded by two thrust faults one from southeast and the other from northwest. Time and depth contour models shows that anticline limbs at north-western side are steep as compared to south-eastern limbs. Seismic interpretation indicates the presence of well-developed anticline bounded by three faults in the cover sequence and one fault in basement and thus the structure may act as a trap for hydrocarbons. The petrophysical analysis of Balkassar-OXY-1 well shows about 83.1% hydrocarbons saturation in the reservoir rocks, hence this study suggest that Balkassar Oilfield has potential to produce hydrocarbons. 相似文献
253.
Mohd Yawar Ali Khan Khalid Muzamil Gani Govind Joseph Chakrapani 《Environmental Earth Sciences》2017,76(5):231
The River Ganges being the most sacred river and lifeline to millions of Indians in serving their water requirements is facing excessive threat of pollution. Under various river management and conservation strategies for its protection, the assessment of water quality of its main tributary Ramganga River is lacking. This study focuses on assessment of physicochemical and heavy metal pollution of the Ramganga River by application of multivariate statistical techniques. Sampling of Ramganga River at sixteen sampling sites was carried out in three seasons (summer, monsoon and winter) of 2014. The collected water samples were analyzed for physicochemical parameters and heavy metals. Results from cluster analysis (CA) of the data divided the whole stretch of the river into three clusters as elevation from 1304 to 259 m as less polluted, from 207 to 154 m as moderately polluted and from elevation 154 to 139 m as high-polluted stretches with anthropogenic as main sources of pollution in high-polluted stretch. Principal component analysis of the seasonal dataset resulted in three significant principal components (PC) in each season explaining 72–8% of total variance with strong loadings (>0.75) of PC1 on fluoride (F?), chloride (Cl?), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), bicarbonate (HCO3 ?), total dissolved solids and electrical conductivity. Temporal variation by one-way ANOVA (Analysis of Variance) showed significant seasonal variation was in the pH, chemical oxygen demand, biochemical oxygen demand, turbidity, HCO3 ?, F?, Zn, cadmium (Cd) and Mn (p < 0.05). Turbidity showed approximately a twofold increase in monsoon season due to rainfall in the catchment area and subsequent flow of runoff into the river. Concentration of HCO3 ?, F? and pH also showed similar increase in monsoon. The concentration of Zn, Cd and Mn showed an increasing trend in summers compared to monsoon and winter season due to dilution effect in the monsoon season and its lasting effect in winters. 相似文献
254.
Sattam Almadani Hussain Alfaifi Abdullah Al-Amri Mohamed Fnais Elkhedr Ibrahim Kamal Abdelrahman Mohammed Shehata Faisal Zaidi 《Arabian Journal of Geosciences》2017,10(6):139
This study was carried out in the Alwadeen area of Khamis Mushayt district of southwestern Saudi Arabia to evaluate the hydrochemical characteristics of the shallow hard rock aquifers. These hard rock aquifers mostly comprise granites and contain significant quantities of groundwater that complement the available groundwater from the unconsolidated alluvial sediments in the nearby wadis. The field investigation indicates two main fracture sets which intersect each other and are oriented in the west-northwest and east-west directions. The granitic rocks in the area are intruded by coarse-grained and quartz-rich monzogranite and pegmatite veins. Hydrogeologically, the fracture systems are important since they facilitate the groundwater storage and assume the transmissive function during times of groundwater abstraction. Given the fact that groundwater in the fractured rock aquifers generally occurs at shallow depths, it may be exposed to contamination from surface and/or near-surface sources, and it is therefore important to evaluate its quality. To this end, a hydrochemical analysis was carried out on six groundwater samples collected from the area. The hydrochemistry revealed that the groundwater is fairly fresh, and facies analysis reveals mixed Na-Cl and Ca-Mg-Cl-SO4 types. Overall, the results reveal that the groundwater is saturated with calcite and dolomite, but unsaturated with gypsum and halite. The degree of salinity increases in the direction of the groundwater flow due to increased rock-water interaction. 相似文献
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