Selection of shelters after earthquake using probabilistic seismic aftershock hazard analysis and remote sensing

Natural Hazards - After a major earthquake, one of the main tasks is to identify temporary shelters. In this study, we utilized probabilistic aftershock hazard analysis based on land use...     

Geochemistry of Cd in groundwater of Winder,Balochistan and suspected health problems

Sedimentary rocks of Jurassic age (Ferozabad group) and igneous rocks (Bela Ophiolite) of Cretaceous age are widely exposed in the east of Winder Town, Balochistan. Representative 48 water and soil samples were collected and analyzed for Cd and other elements. The present study showed that water samples were contaminated by the Cd ion and most of the samples have higher concentration than prescribed WHO standards (3 μg/l) for drinking purpose. The concentration of Cd ions ranged between 1 and 30 with mean values of 10 μg/l and was found high in the vicinity of outcrops. The alkaline pH (av. 7.42) was mainly responsible for elevated Cd content in the water, having near equal molar proportions of Ca and HCO₃ ions. Computed relative mobility values appeared as 0.23, indicating poor leaching from rocks and metal load in the groundwater is also measured low. The estimated values of mobility reflect fairly high mobility of Cd in the study area, decreases with distance from outcrops. The health hazard indices of drinking water was high (av. 1.33) with respect to safe average daily intake of Cd. The consumption of high Cd-bearing water may induce many disorders in the human health.     

Study of subsurface features using seismic reflection data in Erbil area,Kurdistan Region,Iraq

The present study seeks to interpret seismic reflection data for an area measuring approximately about 1,450 km² within the Erbil plain in the Kurdistan Region of Iraq to produce subsurface geological pictures. Thirteen seismic lines were identified by the Iraqi Oil Exploration Company using dynamite sources and then processed; then, a seismic line, BH-15, of around 432.5 km total length was used in this study. Three horizons (reflectors) were selected and identified by tying them directly to Demir Dagh well no. 1, these are H1, a reflector that represents the near top of the Lower Fars Formation; H2, a reflector that represents the top of the Pila Spi Formation; and H3, a reflector that represents the top of the Shiranish Formation. The qualities of the reflectors range between fair and good. All the isochrone and depth maps and 3D view pictures of the reflectors show the same main subsurface structural features trending in a NW–SE direction, namely, Erbil trough, Sherawa trough, and the southeastern plunge of the Demir Dagh anticline. Ninety-five normal and reverse-type faults trending in a NW–SE direction were detected. Also, the maps show that the reflectors tend to increase in dipping and deepening towards the southeastern and eastern parts.     

Variation of ground-motion amplification and structural dynamic characteristics of Amman citadel

Structural remains of the site refer to clear evidence of large historical earthquakes that strongly affected the site during the last 2,000 years. In this work, we present a study of dynamic behavior of Jabal Al-Qalaa site as well as the dynamic behavior of some archeological remaining structures on the site using the free oscillation of surface geology and structures. In this study, seven ground records were obtained along approximately east–west profile, crossing the top of the hill zone. Structural records were obtained at three selected structures following administrative requirements. All structural records were conducted at the top level of each structure using three components seismometer of 2 Hz free oscillation. Horizontal sensors were oriented with respect to the longitudinal and transverse direction of structural horizontal projection. Used orientations are essential for obtaining both structural fundamental modes in the longitudinal and transverse directions. Moreover, damping factors for each horizontal fundamental mode were calculated based on the obtained FFT spectrums of each orientation using half-width band method. Analysis shows that all inspected structures in this study are of high frequency. Interesting results of records obtained at the Umayyad Alcazar, relatively low damping factor as well as sharp fundamental modes in its both longitudinal and transverse directions are recorded at this well-preserved old historical structure. Free-field records were conducted along approximately E-W profile crossing the top of the hill. The purpose of this methodology is to identify the variation of H/V amplification along with, and to find out the topographical effect of this convex geological feature. Obtained H/V ground resonance dominant modes as well as the site amplification reflect well the topographical effect of the citadel hill zone. Amplification gradually increases to reach 4.5 at the top of the hill.     

Evaluation of site amplification, structural dynamic characteristics, and structural vulnerability rating of the city of Aqaba

The potential to destroy any structure during earthquakes depends on the structural design, vulnerability rating, percentage of structural elongation as compared with the natural quiet conditions, the dynamic characteristics of structure itself, as well as the dynamic characteristics of the site. Thus, factors related to the dynamic characteristics of structure and the dynamic characteristics of the site are necessary in the design of resistant structures against earthquakes. In this study, recordings of free oscillation were made directly on 18 selected structures in the urban city of Aqaba, which represent the structural culture of the city and the whole Jordan in general. Ground ambient vibration records were conducted at 18 nearby location at a few meters away from each structure. Records were conducted during the maximal cultural activities using three-component seismometer of 2 Hz free oscillation. Analytical results of records obtained on structures, has given the following equation: $ f = {18}/N $ , where f, is the fundamental mode of structure and N, is the number of stories. All structural records were conducted at the top level of each structure except at Shmesani 4 and 7. Horizontal sensors were oriented with respect to the longitudinal and transverse direction of structural horizontal projection. Damping factors for each structural longitudinal and transverse fundamental mode were calculated based on the obtained FFT spectrums of each orientation using half-width band method. Analysis of obtained records on structures in Aqaba show that most of them are of short periodic structures except a few multi-story tall buildings. Most of the results obtained on structures refer to damping factors that range between 0.05 and 0.208. Mathematical relation derived from this study above, in addition to the actual calculated damping factor, refers to non-compliance with the standards of earthquake-resistant design. Results of ground records analysis indicate to the westward and north-westward decrease of dominant frequency relative to the eastern and southeastern part of the study area, where the crystalline granite bedrock is much shallower reflecting the actual condition of surface geology. Striking that the H/V amplification was relatively higher in the scope of areas where the thicknesses of soft surface deposits in the eastern and southeastern part are much shallower relative to the western and north-western part of the study area. This can be interpreted as a result of much higher impedance contrast in the eastern and southeastern part relative to the western and northwestern parts of the study area.     

Hydrogeochemistry of the Winder River and adjoining tributaries, Balochistan, Pakistan

Quantitative estimation of ground and stream waters draining through sedimentary rocks of the Pab and Mor ranges (Jurassic-Cretaceous) and the Bela ophiolite has been made. The degree of correspondence among cations and anions has been estimated in order to evaluate their mutual relationships. The abundance of major ions is interpreted to be related to bedrocks and climatic conditions, which may contribute to the genetic affiliation. The log TDS and Na/Na Ca ratio reflected supremacy of weathering of rocks with some influence of evaporation. Ionic relationship is exhibited in the form of Stiff diagrams. Patterns of ionic composition revealed high NaCl, medium Ca(HCO3)2 and low MgSO4. Piper diagram has been used to classify the hydrofacies. The important hydrogeochemical parameters have been estimated for assessment of groundwater quality for domestic purposes in accordance to WHO. Irrigation water qualities have been evaluated in terms of EC, SAR, RSC, ESP and pH.     

Experimental and analytical evaluation of the consolidation of tower 8 in the Damascus citadel

The object of this work is a building situated in the ancient citadel of Damascus: tower 8 which has been affected by devastating earthquakes and subjected to a consolidation process thanks to the Syrian–Italian Cooperation Project. The aim of this research is to investigate the dynamic characteristics of this consolidated structure. Hence, a mixed procedure of experimental measurements and analytical analysis has been chosen. Considering the geotectonic environment and the historical importance, ambient noise measurements are preferred as being a non-destructive technique and the most suitable for the study purpose. The dynamic characteristics of tower 8 are analyzed experimentally and analytically on the basis of ambient noise measurements, which have been performed on the ground and floors of the tower. With spectral analysis of ambient noise records, the predominant frequencies, amplification factors, and damping ratios have been determined. The experimental and analytical results have allowed verifying the efficiency of the consolidation interventions in tower 8.     

New set of geometrical and physical elements of the two variable stars SW lacertae and OO aquilae

Photoelectric observations of the two eclipsingvariables, were obtained in UBV standard system, for SWLac and, inVB standard system for OOAql.A new set of geometrical and physical elements for thesystems were obtained from both minima, through theirmagnitude variation during the observation time using themethod of: Fourier Analysis Techniques in-Frequency-domain for thelight curve changes. The two eclipsing variables are contact, the firstcontact angle was 48.1^° for SW Lac and 47.7^° for OO Aql.Absolute elements and effective temperatures of the twocomponents for both systems are derived.