Analysis of largest earthquakes in Turkey and its vicinity by application of the Gumbel III distribution     

Theodoros M. Tsapanos  Yusuf Bayrak  Hakan Cinar  George Ch. Koravos  Erdem Bayrak  Eleni E. Kalogirou  Athina V. Tsapanou  Georgia E. Vougiouka 《Acta Geophysica》2014,62(1):59-82

A study of the spatial distribution of seismicity parameters is undertaken along Turkey and its vicinity, using the Gumbel’s third asymptotic distribution of extreme values (GIII). The data set used spans of 111 years (1900–2010). The seismicity of the whole region is subdivided into equal area mesh of 1° lat. × 1° long. Various seismicity parameters examined, resulted from the application of the GIII method. The results show a quite good correlation between the seismicity parameters and the tectonic regime of the studied area. For instance high values concentrated around North Anatolian Fault. The x ²-test is applied throughout the whole process and in every stage of GIII, in order to check the accuracy of the obtained results. The spatial distribution of upper-bound (ω) formed a W-shape pattern, which shows the difference in the mechanical structure of the materials in the examined area.  相似文献   

Vibration characteristics of a suspension bridge under traffic and no traffic conditions     

Nurdan Memişoglu Apaydın  Yavuz Kaya  Erdal Şafak  Hakan Alçık 《地震工程与结构动力学》2012,41(12):1717-1723

This paper presents the variations of vibration under different traffic conditions on the Fatih Sultan Mehmet suspension bridge in Istanbul, Turkey.The main intention is to determine the vibration amplifications under heavy-traffic as opposed to no-traffic conditions. This is the first study in this particular area that has been performed on this bridge, over which an average of 200,000 cars pass daily. Two full-scale ambient vibration surveys were carried out on two different days to determine the response of the bridge to diverse traffic conditions. Initial measurements were taken as the bridge experienced heavy stress conditions caused by rush-hour traffic. Secondary measurements were recorded after closing the bridge to traffic. The data were analyzed to gauge the vibration effects of heavy-traffic conditions on the bridge and to determine the effects of different traffic conditions on the free vibration characteristics of the bridge. The analyses were performed utilizing different amplification methods. Results show that there are important differences in the amplifications of the vibration amplitudes. Especially heavy-traffic on the bridge causes the vibration response of the bridge to be intensified in comparison to no-traffic conditions. Additionally, predominant frequencies are shifted as a direct result of traffic load acting on the bridge. Even more importantly and is probably analogous for all long-span bridges, is the fact that any movement causing vibration on the bridge is carried and amplified along its length. These significant amplifications indicate the important effect of varying traffic loads and how the bridge responds to the diverse movements it experiences. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Joint inversion of Rayleigh‐wave dispersion data and vertical electric sounding data: synthetic tests on characteristic sub‐surface models          下载免费PDF全文

M. Senkaya  H. Karslı 《Geophysical Prospecting》2016,64(1):228-246

In the traditional inversion of the Rayleigh dispersion curve, layer thickness, which is the second most sensitive parameter of modelling the Rayleigh dispersion curve, is usually assumed as correct and is used as fixed a priori information. Because the knowledge of the layer thickness is typically not precise, the use of such a priori information may result in the traditional Rayleigh dispersion curve inversions getting trapped in some local minima and may show results that are far from the real solution. In this study, we try to avoid this issue by using a joint inversion of the Rayleigh dispersion curve data with vertical electric sounding data, where we use the common‐layer thickness to couple the two methods. The key idea of the proposed joint inversion scheme is to combine methods in one joint Jacobian matrix and to invert for layer S‐wave velocity, resistivity, and layer thickness as an additional parameter, in contrast with a traditional Rayleigh dispersion curve inversion. The proposed joint inversion approach is tested with noise‐free and Gaussian noise data on six characteristic, synthetic sub‐surface models: a model with a typical dispersion; a low‐velocity, half‐space model; a model with particularly stiff and soft layers, respectively; and a model reproduced from the stiff and soft layers for different layer‐resistivity propagation. In the joint inversion process, the non‐linear damped least squares method is used together with the singular value decomposition approach to find a proper damping value for each iteration. The proposed joint inversion scheme tests many damping values, and it chooses the one that best approximates the observed data in the current iteration. The quality of the joint inversion is checked with the relative distance measure. In addition, a sensitivity analysis is performed for the typical dispersive sub‐surface model to illustrate the benefits of the proposed joint scheme. The results of synthetic models revealed that the combination of the Rayleigh dispersion curve and vertical electric sounding methods in a joint scheme allows to provide reliable sub‐surface models even in complex and challenging situations and without using any a priori information.  相似文献   

Assessment of geo-environmental properties depressing urban development with GIS: a case study of Kozlu settlement,Turkey     

Deniz Arca  Hulya Keskin Citiroglu  Hakan S. Kutoglu  Cetin Mekik  Tomonori Deguchi 《Natural Hazards》2017,87(1):307-322

Kozlu is a mining town only 5 km away from the main city of Zonguldak and initially was not favored for settlement due to its rugged and hilly topography. However, along with hard coal production in large quantities throughout the years came the industrialization at its full speed with plenty job opportunities which then gave rise to intense population in the region where there were only a few sheds and slums just a century ago. Workers migrating to Kozlu in thousands needed dwellings to live in, but the law, so-called the Coal Basin Restrictions Law which came in effect in 1910, hindered the implementation of zoning plans. Planned housing was not possible in the region not until the abolishment of the law in 1986. During these 76 years, the settlement in the area mostly by the mining and industry workers was carried out without proper zoning plans, usually on demand basis. Today because of this unplanned housing and harsh topography, the Kozlu settlement area (KSA) has a history of being attraction point for many natural and man-made disasters which can be summarized as are topography, geological and carstic structure, mining activities and mass movements. In this study, a settlement suitability map is produced for the study area using a geographic information system. The map produced is designated into four settlement suitability zones, namely suitable to settlement, slightly suitable to settlement, suitable to settlement with precautions and unsuitable to settlement. It clearly shows that 24.73% of the study area lies in suitable and slightly suitable to settlement areas while the bulky rest pertains to suitable to settlement with precautions and unsuitable to settlement. The latest studies show that the 37.5% of the buildings and houses in the KSA are situated on the lithologic units identified as hydrogeological permeable and semipermeable, 7.8% on carstic caverns and a hefty rate of 47.6% on the surfaces deformed by mining-induced subsidence. Therefore, it is needless to claim that the administrators of Kozlu should promptly develop a settlement plan for the welfare of the city.  相似文献   

Effect of salt crystallization on weathering of pyroclastic rocks from Cappadocia,Turkey     

Hakan Özşen  Ali Bozdağ  İsmail İnce 《Arabian Journal of Geosciences》2017,10(12):258

Salt crystallization is the most significant factor in the degradation of the natural stones used in cultural and historical structures. Stones decay partially or fully as a result of this exposure. This study is the investigation of the degradation of historical monuments (underground cities and semi-underground settlements) carved in pyroclastic rocks in Cappadocian Region which takes part in World Cultural Heritage List. Samples of pyroclastic rocks were collected from six different quarries in Cappadocia, Turkey. To understand the contribution of salt crystallization to this weathering, dry weight loss (DWL) tests were performed on these samples. To investigate the correlations between salt crystallization and other rock properties, porosity, water absorption, ultrasonic velocity, uniaxial compressive strength, Brazilian tensile strength, and point load index were also measured. During the SC process of weathering, the results showed that porosity and water absorption increased for all the samples whereas ultrasonic velocity, uniaxial compressive strength, tensile strength, and point load index values decreased. Evaluation of the data obtained from these tests showed very high logarithmic correlations between the dry weight loss values and the mechanical properties.  相似文献   

In situ gamma ray measurements for deciphering of radioactivity level in Sarıhan pluton area of northeastern Turkey     

Hakan Çınar  Suna Altundaş  Necati Çelik  Nafız Maden 《Arabian Journal of Geosciences》2017,10(19):435

The present work utilizes in situ gamma ray spectrometric measurement data to map the surface geology of Sar?han Granitoid and its surrounding area. The study area comprises three different lithological units, namely, Hozbirikyayla Formation (limestone and sandy limestones), Sar?han Granitoid (consist of quartz monzodiorite, granodiorite and quartz diorite) and the Ophiolitic olistostromal melange (andesite, basalt, sandstone, gravelly sandstone). When lithological units are assessed according to the radioactivity characteristics, natural radionuclide contents (⁴⁰K and radionuclides from ²³⁸U and ²³²Th series) of Hozbirikyayla limestones and ophiolitic melange rocks are lower than the Sar?han pluton. The U, Th and K radionuclide contents were found to be 0.8–5.4 ppm, 10.1–33.6 ppm and 1.29–4.41% in the Sar?han plutonic area and 0.9–5.3 ppm, 1.1–20.3 ppm and 0.04–2.71% in Horzbirikyayla formation, respectively. The element concentrations of ²³⁸U, ²³²Th and ⁴⁰K of the Ophiolitic melange are 1.1–4.5 ppm, 1.6–25.3 ppm and 0.09–3.63%, respectively. Radioelement ratio maps are created for the studied area, because the parameters of radioelement ratios, eU/eTh, eU/K and eTh/K, reflect the radioactive characters of the rock and soil. The Hozbirikyayla Formation is characterized by the highest value of eU/eTh and lowest value of eTh/K. While the lowest eU/eTh and eU/K ratios were observed in the Sar?han Granodiorite, the highest value of eU/K and eTh/K were obtained in the Ophiolitic olistostromal melange. By comparing these maps with the geology, it was found that the radioelement concentrations are in good agreement with the geological properties of the region. In addition to this, the radiation hazard parameters were evaluated to assess the radiation hazard for people living in this area. It has also been found that there is no significant radiologic hazard for humans and the environment in and around studied area.  相似文献   

Evaluation of ground vibration effect of blasting operations in a magnesite mine     

Hakan Ak  Melih IpharMahmut Yavuz  Adnan Konuk 《Soil Dynamics and Earthquake Engineering》2009

Ground vibrations induced by blasting are one of the fundamental problems in the mining industry and may cause severe damage to structures and plants nearby. Therefore, a vibration control study plays an important role in the minimization of environmental effects of blasting in mines. This paper presents the results of ground vibration measurement induced by bench blasting at Magnesite Incorporated Company (MAS) open pit mine in Turkey. The scope of this study is to predict peak particle velocity and to determine the slope of the attenuation curve for this site. For this purpose, the blasting parameters of 43 shots were carefully recorded and the ground vibration components were measured for each event. After carrying out statistical analysis, the site specific parameters were determined to predict the peak particle velocity. In the light of this analysis, the prediction graphics of maximum charge weight per delay versus distance for different damage criteria was proposed to be able to perform controlled blasting in order not to damage to the nearby structures, especially to the plant where rotary and shaft kilns have been established.  相似文献   

On the cumulant expansion up scaling of ground water contaminant transport equation with nonequilibrium sorption     

Hakan Sirin  Miguel A. Mariño 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(3):411-411

  相似文献   

Temperature Trends and Changes in Rize,Turkey, for the Period 1975 to 2007     

Lokman Hakan Tecer  Orhan Cerit 《洁净——土壤、空气、水》2009,37(2):150-159

There is increasing evidence that the global climate is changing as a result of anthropogenic activity. Short‐term mean, maximum, and minimum temperatures of the city Rize located at the Eastern Black Sea Coast of Turkey were analyzed to reveal trends, change points, significant warming (cooling) periods, and trend rates per year. An increasing trend of approximately 1.27°C/33 years (α = 0.001) in the annual mean temperatures is found during the period from 1975 to 2007. Two periods, averaging 13.78 and 14.66°C, respectively, were detected from fluctuation in the annual mean temperatures. The trend of the first period (1975–1993) is towards a cooler climate, whereas the trend of the second period (1994–2007) is towards a warmer climate. Summer, autumn and, particularly, the spring mean temperatures have tended to increase strongly, whereas the winter mean temperatures have increased slightly over the whole period. For the winter mean temperature, the trend rate indicates a slight increase, which is insignificant. Maximum temperatures have dramatically increased with 1.61°C (α = 0.001) over the last 33 years. However, annual minimum temperatures have increased by 0.99°C (α = 0.01) over the same period.  相似文献   

Development of New Electrochemical Surfaces for the Detection of Metals in Waste Water     

Yasemin Oztekin  Zafer Yazicigil  Tolga Duran  Hakan Dumrul  Ersin Guler  Ozcan Kocyigit 《洁净——土壤、空气、水》2010,38(10):921-926

In this study, electrochemical experiments were performed in non‐aqueous media in order to determine electrochemical behavior of some of the glyoxime derivatives (GDs). Phenylglyoxime (PG), p‐chloro‐phenylglyoxime (p‐CPG), and 1,2‐phenylendiamino‐p‐chlorophenylglyoxime (PACPG) were chosen as GDs. Pt wire, Ag/Ag⁺ (in 0.01 M AgNO₃) and glassy carbon (GC) electrode were used as counter, reference, and working electrode, respectively. The multiscan cyclic voltammograms (CVs) of these compounds were registered in acetonitrile (MeCN) containing 0.1 M tetrabutylammonium tetrafluoroborat (TBATFB) at scan rate of 100 mV/s. The potential was swept from 0 to +2.0 V versus Ag/Ag⁺ (0.01 M). The CVs of GDs were compared with each other and the electrochemical behaviors of the compounds were investigated depending on the functional groups in their structures. The electrochemical characterization of these modified surfaces was performed and characterizations were compared with the chatacterization results of bare GC surfaces. The application areas for new surfaces were investigated. These results will be active in the disciplines of electrochemistry and industrial physical chemistry, and in related industrial fields at the dissemination of new information for scientific area.  相似文献