Lineaments in the Shamakhy–Gobustan and Absheron hydrocarbon containing areas using gravity data     

Ali Elmas  Hakan Karsli  Fakhraddin A. Kadirov 《Acta Geophysica》2018,66(1):39-49

In this study, we purposed to investigate the edge of geostructures and position of existing faults of the Shamakhy–Gobustan and Absheron hydrocarbon containing regions in Azerbaijan. For this purpose, the horizontal gradient, analytic signal, tilt angle, and hyperbolic of tilt angle methods were applied to the first vertical derivative of gravity data instead of Bouguer gravity data. We obtained the maps that show the previous lineaments which were designated by considering the maximum contours of horizontal gradient, analytic signal maps, and zero values of tilt angle, hyperbolic of tilt angle maps. The geometry of basement interface was also modeled utilizing the Parker–Oldenburg algorithm to understand the sediment thickness and coherency or incoherency between the gravity values and basement topography. The lineaments were held a candle to most current tectonic structure map of the study area. It was seen that the techniques used in this study are very effective to determine the old and new lineaments in the Shamakhy–Gobustan and Absheron regions. The epicenter distribution of earthquakes within the study area supports the new lineaments which are extracted by our interpretation. We concluded that better comprehension of Azerbaijan geostructures and its effect on the large scale works will be provided by means of this study.  相似文献   

Three-parameter Radon transform in layered transversely isotropic media     

Mohammad Mahdi Abedi  Mohammad Ali Riahi  Alexey Stovas 《Geophysical Prospecting》2019,67(2):395-407

Radon transform is a powerful tool with many applications in different stages of seismic data processing, because of its capability to focus seismic events in the transform domain. Three-parameter Radon transform can optimally focus and separate different seismic events, if its basis functions accurately match the events. In anisotropic media, the conventional hyperbolic or shifted hyperbolic basis functions lose their accuracy and cannot preserve data fidelity, especially at large offsets. To address this issue, we propose an accurate traveltime approximation for transversely isotropic media with vertical symmetry axis, and derive two versions of Radon basis functions, time-variant and time-invariant. A time-variant basis function can be used in time domain Radon transform algorithms while a time-invariant version can be used in, generally more efficient, frequency domain algorithms. Comparing the time-variant and time-invariant Radon transform by the proposed basis functions, the time-invariant version can better focus different seismic events; it is also more accurate, especially in presence of vertical heterogeneity. However, the proposed time-invariant basis functions are suitable for a specific type of layered anisotropic media, known as factorized media. We test the proposed methods and illustrate successful applications of them for trace interpolation and coherent noise attenuation.  相似文献   

Statistical evaluation and probabilistic modeling of aftershock sequences of Iranian plateau     

Ali Khansefid  Ali Bakhshi 《Journal of Seismology》2018,22(5):1249-1261

The present research focuses on the statistical evaluation of Iranian plateau aftershocks from an engineering perspective and presents probabilistic models applicable for generating random earthquake scenarios. Accordingly, a comprehensive earthquake data catalog including the period from 1964 to 2016 is prepared. Data are declustered into 37 separate mainshock-aftershock sequences by considering the completeness moment magnitude of the database. The well-known modified Omori occurrence rate formula is adopted to determine the recurrence time of the events, considering the effect of secondary aftershocks. In addition to computing the probability density functions of the parameters of the Omori formula, the joint probability distribution of the aftershock occurrence versus magnitude and occurrence time is obtained for modeling their magnitude sequences. The obtained results are applicable for producing randomly generated mainshock-aftershock scenarios.  相似文献   

Uncertainty analysis of urban sewer system using spatial simulation of radar rainfall fields: New York City case study     

Ali?HamidiEmail authorView author&#;s OrcID profile  David?J.?Farnham  Reza?Khanbilvardi 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(8):2293-2308

The goal of this study is to investigate the uncertainty of an urban sewer system’s response under various rainfall and infrastructure scenarios by applying a recently developed nonparametric copula-based simulation approach to extreme rainfall fields. The approach allows for Monte Carlo simulation of multiple variables with differing marginal distributions and arbitrary dependence structure. The independent and identically distributed daily extreme rainfall events of the corresponding urban area, extracted from nationwide high resolution radar data stage IV, are the inputs of the spatial simulator. The simulated extreme rainfall fields were used to calculate excess runoff using the Natural Resources Conservation Service’s approach. New York City is selected as a case study and the results highlight the importance of preserving the spatial dependence of rainfall fields between the grids, even for simplified hydrologic models. This study estimates the probability of combined sewer overflows under extreme rainfall events and identifies the most effective locations in New York City to install green infrastructure for detaining excess stormwater runoff. The results of this study are beneficial for planners working on stormwater management and the approach is broadly applicable because it does not rely on extensive sewer system information.  相似文献   

Seismic fragility functions for code compliant and non-compliant RC SMRF structures in Pakistan     

Naveed Ahmad  Asif Shahzad  Qaisar Ali  Muhammad Rizwan  Akhtar Naeem Khan 《Bulletin of Earthquake Engineering》2018,16(10):4675-4703

Fragility functions are derived for low-rise code compliant & non-compliant special moment resisting frames (SMRFs). Non-compliant SMRFs those built in low strength concrete and lacking confining ties in joint panel zones, commonly found in developing countries. Shake table tests were performed on single-storey and two-storey 1:3 reduced scale representative frames to understand the damage mechanism and develop deformation-based damage scale. The non-compliant SMRF experienced column flexure cracking, longitudinal bar-slip in beam and observed with cover concrete spalling from the joint panels. The code compliant SMRF experienced flexure cracks in beam/column, and experienced joint cracking under extreme shaking. Numerical modeling technique is developed for inelastic modeling of reinforced concrete frame with beam bar-slip and joint damageability using SeismoStruct. Natural accelerograms were used to analyze the considered frames through incremental dynamic analyses in SeismoStruct. A probabilistic based approach was used to derive fragility functions for the considered frames. An example case study is presented for damageability evaluation of structures for earthquakes of various return periods (43, 72, 475, 2475 years).  相似文献   

Deterministic and fuzzy-based methods to evaluate community resilience     

Omar Kammouh  Ali Zamani Noori  Veronica Taurino  Stephen A. Mahin  Gian Paolo Cimellaro 《地震工程与工程振动(英文版)》2018,17(2):261-275

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Dissolved inorganic carbon evolution in neutral discharge from mine tailings piles          下载免费PDF全文

Hendratta N. Ali  Eliot A. Atekwana 《水文研究》2016,30(13):2079-2091

We measured the concentrations of dissolved inorganic carbon (DIC) and major ions and the stable carbon isotope ratios of DIC (δ¹³C_DIC) in two creeks discharging from carbonate‐rich sulphide‐containing mine tailings piles. Our aim was to assess downstream carbon evolution of the tailings discharge as it interacted with the atmosphere. The discharge had pH of 6.5–8.1 and was saturated with respect to carbonates. Over the reach of one creek, the DIC concentrations decreased by 1.1 mmol C/l and δ¹³C_DIC increased by ~4.0‰ 200 m from the seep source. The decrease in the DIC concentrations was concomitant with decreases in the partial pressure of CO_2(aq) because of the loss of excess CO_2(aq) from the discharge. The corresponding enrichment in the δ¹³C_DIC is because of kinetic isotope fractionation accompanying the loss of CO_2(g). Over the reach of the other creek, there was no significant decrease in the DIC concentrations or notable changes in the δ¹³C_DIC. The insignificant change in the DIC concentrations and the δ¹³C_DIC is because the first water sample was collected 160 m away from the discharge seep, not accessible during this research. In this case, most of the excess CO_2(aq) was lost before our first sampling station. Our results indicate that neutral discharges from tailings piles quickly lose excess CO_2(aq) to the atmosphere and the DIC becomes enrich in ¹³C. We suggest that a significant amount of carbon cycling in neutral discharges from tailings piles occur close to the locations where the discharge seeps to the surface. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Weakly compressible SPH simulation of cnoidal waves with strong plunging breakers     

Sarfaraz  Mohammad  Pak  Ali 《Ocean Dynamics》2019,69(6):657-678

Ocean Dynamics - Hydrodynamics of highly nonlinear cnoidal waves and their subsequent strong plunging breakers are among the least understood and most significant issues in coastal engineering. In...  相似文献   

Wave breaking and bubble formation associate energy dissipation and wave setup     

Hoque  Ashabul  Hossain  Nur  Ali  Shuzon  Rahman  Masudar 《Ocean Dynamics》2019,69(8):913-923

Ocean Dynamics - In this work, theoretical development of void fraction effect over wave energy dissipation and wave setup in a surf zone is made. The formulation incorporates simple energy...  相似文献   

Research note: deblended-data reconstruction using generalized blending and deblending models     

Tomohide Ishiyama  Mohammed Y. Ali  Satoshi Ishikawa  Gerrit Blacquiere  Shotaro Nakayama 《Geophysical Prospecting》2019,67(7):1852-1866

We introduce a concept of generalized blending and deblending, develop its models and accordingly establish a method of deblended-data reconstruction using these models. The generalized models can handle real situations by including random encoding into the generalized operators both in the space and time domain, and both at the source and receiver side. We consider an iterative optimization scheme using a closed-loop approach with the generalized blending and deblending models, in which the former works for the forward modelling and the latter for the inverse modelling in the closed loop. We applied our method to existing real data acquired in Abu Dhabi. The results show that our method succeeded to fully reconstruct deblended data even from the fully generalized, thus quite complicated blended data. We discuss the complexity of blending properties on the deblending performance. In addition, we discuss the applicability to time-lapse seismic monitoring as it ensures high repeatability of the surveys. Conclusively, we should acquire blended data and reconstruct deblended data without serious problems but with the benefit of blended acquisition.  相似文献