Impact of mass movements in the Kocaeli Province,Turkey     

Ahmet Karakaş  Özkan Coruk 《Geology Today》2011,27(2):70-73

Recent mass movements in the Kocaeli Province, Turkey in 2010 caused damage to people, property and infrastructure, especially in Izmit and its vicinity. The causes and impact of these mass movements are outlined, so as to increase awareness of their dangerous aspects. Some of these mass movement events took place in urban areas, bringing attention to the need for better and more effective land use practices. The impact of these movements indicates the benefit there would be from geology and engineering geology in the planning of any property development and land use.  相似文献   

A study of residuals for strong ground motions in Adapazari basin,NW Turkey,by ground motion prediction equations (GMPEs)     

Ergin Ulutaş  Özkan Coruk  Ahmet Karakaş 《Studia Geophysica et Geodaetica》2011,55(2):213-240

The city of Adapazarı — located in the Marmara Region of northwest Turkey — is situated on a deep sedimentary basin and was the city most heavily damaged by the strong ground motion of the 17 August 1999 Kocaeli earthquake (moment magnitude M_w = 7.4). This study determines site amplifications of the attenuation relationships for shallow earthquakes in the Adapazarı basin by using the previous ground motion prediction equations (GMPEs) and the traditional spectral ratio method. The site amplifications are determined empirically by averaging the residuals between the observed and predicted peak ground acceleration (PGA) and spectral acceleration (SA) values for various periods. Residuals are significantly correlated with the known characteristics of geological units. A new attenuation model has also been developed for 5% damped spectral acceleration to determine the dependence of strong ground motions on frequency.  相似文献   

Holocene coastal change in the ancient harbor of Yenikap?-?stanbul and its impact on cultural history     

Oya Algan  M. Nam?k Yalç?n  Yücel Y?lmaz  Elmas K?rc?-Elmas  Özlem Bulkan  Cem Gazio?lu  Mehmet Ali Polat 《Quaternary Research》2011,76(1):30-45

An extensive rescue excavation has been conducted in the ancient harbor of ?stanbul (Yenikap?) by the Sea of Marmara, revealing a depositional sequence displaying clear evidence of transgression and coastal progradation during the Holocene. The basal layer of this sequence lies at 6 m below the present sea level and contains remains of a Neolithic settlement known to have been present in the area, indicating that the sea level at ~ 8-9 cal ka BP was lower than 6 m below present. Sea level advanced to its maximum at ~ 6.8-7 cal ka BP, drowning Lykos Stream and forming an inlet at its mouth. After ~ 3 cal ka BP, coastal progradation became evident. Subsequent construction of the Byzantine Harbor (Theodosius; 4th century AD) created a restricted small basin and accumulation of fine-grained sediments. The sedimentation rate was increased due to coastal progradation and anthropogenic factors during the deposition of coarse-grained sediments at the upper parts of the sequence (7th-9th centuries AD). The harbor was probably abandoned after the 11th century AD by filling up with Lykos Stream detritus and continued seaward migration of the coastline.  相似文献   

Erratum to: Assessment of potential seismic hazard and site effect in Antakya (Hatay Province), SE Turkey     

Semir Över  Aydın Büyüksaraç  Özcan Bektas  Ahmet Filazi 《Environmental Earth Sciences》2011,62(2):327-327

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Astrometric Solution of the Multiple System Xy Leo     

Volkan Bakis  Ahmet Erdem  Edwin Budding  Osman Demircan  Hicran Bakis 《Astrophysics and Space Science》2005,296(1-4):131-134

An astrometric solution, together with time of minimum analysis, has been made for the multiple system XY Leonis (HIP 49136) to identify the properties of the remote companion to the eclipsing pair (AB). From this solution, we derive the inclination of the wide orbit (AB-cd) as 94.4^∘± 0.2^∘, angle of nodes as 247.3^∘± 0.2^∘, and the mass of the wide component (the dwarf binary cd) as 0.98 ± 0.2 M_⊙. This study confirms that the light travel time effect can explain the sinusoidal O−C variation of the eclipsing system.  相似文献   

Biomonitoring of heavy metals by <Emphasis Type="Italic">Pseudevernia furfuracea</Emphasis> (L.) Zopf in Ankara (Turkey)     

Atila Yildiz  Ahmet Aksoy  Gul Nilhan Tug  Cemil Islek  Dilek Demirezen 《Journal of Atmospheric Chemistry》2008,60(1):71-81

The objective of this study was to determine the air pollution level of Ankara and to generate the air pollution map of this city by using Pseudevernia furfuracea (L.) Zopf as a biomonitor. Lichen samples were collected from unpolluted area at Yaprakli Mountains, Cankiri in November 2002 and transplanted to 27 localities in Ankara. Lichen samples were retrieved following an exposure of 3 and 6 months. Heavy metal, Cu, Mn, Ni, Pb and Zn, contents were determined by using inductively coupled plasma spectrometry (ICP). The chlorophyll a and b contents were determined by using DMSO method. The increase in Ni, Pb, Zn and chlorophyll a content of the specimens were statistically important. All the increases and decreases in the variables could be explained by the environmental stress like pollution, but it is hard to say that this is the only reason of these changes, also climatic conditions, seasons, strength of the light and the physiological status of the plant itself effective on these changes. According to the results of heavy metal analysis Pseudevernia furfuracea continued to accumulate heavy metals and worked well as a biomonitor. The air pollution level of Ankara shows great variations because of the great area of the city.  相似文献   

Purification of diatomite powder by acid leaching for use in fabrication of porous ceramics   总被引：1，自引：0，他引：1  

Osman an  Remzi Gren  Cem zgür 《International Journal of Mineral Processing》2009,93(1):6-10

This study presents an investigation of the purification of a raw diatomite by acid leaching conducted in hot solution (75 °C and 5 M HCl) for long periods up to 240 h, evaluates the use of these purified powders in the fabrication of porous materials, and examines their porosities. The treatment for 1 h increased the specific surface area of diatomite from 189 m²/g to 222 m²/g, but the SiO₂ content of 78.66% was still low. Material leached for a relatively short time shows an amorphous phase with quartz and plagioclase phases and the plagioclase is removable at longer leaching times during which no disruptive effect on the fine microscopic pores of the particles was observed. Thus, the diatomite based powders have potential use in the fabrication of porous coating as a membrane-separating layer: sintering at a relatively high temperature (1300 °C) still showed a significantly high apparent porosity of 48%.  相似文献   

Identification of aquifer and well parameters from step-drawdown tests     

Cem B. Avci  Emin Ciftci  A. Ufuk Sahin 《Hydrogeology Journal》2010,18(7):1591-1601

A new analysis technique has been proposed for interpreting transient step-drawdown test data. The proposed method is based on taking the derivative of the drawdown with respect to time for the entire pumping test period to eliminate the time-independent well-loss terms. The derivative function is subsequently integrated to obtain the time-dependent aquifer drawdown as a continuous function. The well-loss parameters are then obtained with higher accuracy once the aquifer behavior is identified. The proposed method is applicable for analyzing data obtained not only from ideal confined aquifers but also from other aquifer types (i.e. unconfined) and non-ideal aquifers (i.e. heterogeneous). The technique was tested for synthetically generated and field data; the proposed approach was noted to provide accurate aquifer and well-loss parameter estimates. The results of the proposed method were compared with those of some of the existing methods for analyzing step-drawdown test data and were found to be more reliable and robust.  相似文献   

Visualization of geotechnical data by means of geographic information system: a case study in Eskisehir city (NW Turkey)   总被引：2，自引：2，他引：0  

Ahmet Orhan  Hasan Tosun 《Environmental Earth Sciences》2010,61(3):455-465

Recently, geographic information system Software’s are widely used in engineering geology applications. Such a study was performed in the Eskisehir urban area of about 30 km² via geo-engineering maps, cross-sections and panel-block diagrams, which are formed to predict the properties of foundation soil. In order to determine the engineering geology properties of the region, physical and mechanical characteristics of the soil profile were tested on 1,011 disturbed and 383 undisturbed samples from a total of 170 boreholes. Topographic, lithological and geotechnical data of the region were compiled as a database in computer. Five geological cross-sections were drawn to decipher specifically the alluvial deposits in detail in densely populated areas. Hence, geological characteristics of the area were evaluated in a three-dimensional mode. Five standard penetration test (SPT) cross-sections at the same directions and SPT, uniaxial compressive strength (qu) and soil class Zonation maps were produced at different depths and panel-block diagrams were also created to define the geo-engineering properties of the investigation area. In this respect, the sub-surface of the study area is fully visualized and useful predictor maps, cross-sections and panel-block diagrams are performed to be used in further studies.  相似文献   

Editorial     

C. Emdad Haque  Dale Dominey-Howes  Nuray Karanci  Gerassimos Papadopoulos  Ahmet Yalciner 《Natural Hazards》2003,29(3):307-308

Editorial Introduction

Editorial  相似文献