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Mohammad Abou Romieh Rob Westaway Mohamad Daoud Yousef Radwan Rayan Yassminh Ahlam Khalil Abeer Al‐Ashkar Susan Loughlin Katherine Arrell David Bridgland 《地学学报》2009,21(6):427-437
The Africa–Arabia plate boundary comprises the Red Sea oceanic spreading centre and the left‐lateral Dead Sea Fault Zone (DSFZ); however, previous work has indicated kinematic inconsistency between its continental and oceanic parts. The Palmyra Fold Belt (PFB) splays ENE from the DSFZ in SW Syria and persists for ～400 km to the River Euphrates, but its significance within the regional pattern of active crustal deformation has hitherto been unclear. We report deformation of Euphrates terraces consistent with Quaternary right‐lateral transpression within the PFB, indicating anticlockwise rotation (estimated as 0.3° Ma?1 about 36.0°N 39.8°E) of the block between the PFB and the northern DSFZ relative to the Arabian Plate interior. The northern DSFZ is shown to be kinematically consistent with the combination of Euler vectors for the PFB and the Red Sea spreading, resolving the inconsistency previously evident. The SW PFB causes a significant earthquake hazard, previously unrecognized, to the city of Damascus. 相似文献
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Ashraf Hamdy Mostafa K. Ahmed Mohamad Radwan Fawzy Ahmed Abd El-Salam 《Earth, Moon, and Planets》2003,93(4):261-273
The objective of the present work is to develope explicit analytical expressions for the small amplitude orbits of the infinitesimal
mass about the equilibrium points in the elliptic restricted three body problem. To handle this dynamical problem, the Hamiltonian
for the elliptic problem is formed with the true anomaly and then with the eccentric anomaly as independent variables. The
origin is then transformed to a fixed point and the Hamiltonian is developed up to O(4) in the eccentricity, e, (which plays the role of the small parameter of the problem) of the primaries. The integration of the model problem under
consideration is undertaken by means of a perturbation technique based on Lie series developments, which leads to the solution
of the canonical equations of motion. 相似文献
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The distinction between clast-dominant, matrix-dominant and well-graded tills is important in view of the influence of texture on the definition and function of till fines. Till fabric includes a wide range of features of both primary and secondary origin including folds, thrusts, fissures (the macrofabric), disposition of clasts (the mesofabric) and organization of the matrix (the microfabric). The results of fabric analysis of pebble, granule, sand, silt and clay in small depositional landforms beneath currently-active glaciers are described. Deformation fabrics are distinguished in freshly deposited end moraines and flutes. The sand-size material in deformed till may or may not behave in the same way as larger clasts, depending on the degree to which the till is matrix-dominant. While clasts in saturated subglacial till tend to align themselves sub-parallel to the depositional surface, the matrix usually retains abundant pore spaces. With slow, unloaded drainage, clast fabrics appear to be little modified. Such material is potentially unstable and any subsequent increase in overburden and hydraulic pressures may cause slope collapse and flowtill development. It is concluded that examination of a wide range of fabric parameters provides a means of distinguishing tills of diverse origins and of assessing their potential instability. 相似文献
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Estimating the potential direct runoff for urban watersheds is essential for flood risk mitigation and rainwater harvesting. Thus, this study aims to estimate the potential runoff depth based on the natural resources conservation service (NRCS) method and delineation of the watersheds in Riyadh, Saudi Arabia. To accomplish this objective, the geographic information systems (GIS) and remote sensing technique (RST) data were integrated to save time and improve analysis accuracy. The employed data include the digital elevation model (DEM), soil map, geology map, satellite images, and daily precipitation records. Accordingly, the hydrologic soil groups (HSG), the land use/land cover (LULC), and curve number (CN) were determined for each watershed in the study area. The results of this analysis show that the study area can be delineated into 40 watersheds with a total area of 8500 km2. Furthermore, the dominant HSG is group D, which represents about 71% of the total area. The LULC maps indicate four major land types in the entire study area: urban, barren land, agricultural land, and roads. The CN of the study area ranges from 64 to 98, while the weighted CN is 92 for the city. The rainfall-runoff analysis shows that the area has a high and very high daily runoff (35–50 and >?50 mm, respectively). Therefore, in this case, the runoff leads to flooding, especially in the urban area and agricultural lands. 相似文献
25.
Radwan K. Al-Farawati Mohammad O. Gazzaz Mohammad A. El Sayed Amr El-Maradny 《Arabian Journal of Geosciences》2011,4(7-8):1229-1238
Dissolved Cu, Ni, and Zn were measured in the surface coastal waters of Jeddah, eastern Red Sea during October 2004 and April 2005. High values of trace metals, particularly Zn, were recorded in the Southern Corniche area close to a sewage effluent indicating a significant contribution from the wastewater. Concentrations of trace metals decreased northward and southward under the effect of dilution. Another hot spot was also observed in the vicinity of Jeddah Desalination Plant (JDP) during April 2005 indicating a possible contribution from the JDP to trace metal contents in the study area. Trace metals were correlated to salinity, nutrients and particulate organic carbon (POC). The good association between Zn and reactive silicate and Ni and ammonium is attributed to simultaneous biological utilization and regeneration. The behavior of copper suggested adsorption of Cu onto the POC during October 2004 whereas in April 2005 the most important process seems to be desorption of Cu from the particulate materials. 相似文献
26.
Ahmed E. Radwan 《Astrophysics and Space Science》1991,176(1):85-96
Thermal instability in a high-temperature rotating and gravitating plasma in the central region of our Galaxy has been analyzed in the absence of a magnetic field. The minimum scales of perturbation are calculated using different forms of heat loss function and different values of the parameters involved. The growth rates, the growth times, for these scales are also computed and they have been discussed. 相似文献
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Mutebi Stephen Sen Souvik Sserubiri Tonny Rudra Arka Ganguli Shib Sankar Radwan Ahmed E. 《Natural Resources Research》2021,30(6):4329-4354
Natural Resources Research - The Albertine Graben, an active sedimentary petroliferous basin, has gained global attention as the unexplored areas are recently being targeted for hydrocarbon... 相似文献
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Geotectonics - Aswan region is a very important region for Egypt where the High Dam is situated. The wellbeing of the dam and its encompassing region is of extreme worry to all the Egyptian... 相似文献