Mud Volcanoes and Dome-Like Structures at the Eastern Mediterranean Ridge   总被引：2，自引：0，他引：2  

Çifçi  G.  Limonov  A.  Dimitrov  L.  Gainanov  V. 《Marine Geophysical Researches》1997,19(5):421-438

Marine Geophysical Research - The Mediterranean Ridge is interpreted as a large accretionary complex, which originated due to the northern subduction of the African lithosphere below the Eurasian...  相似文献   

Assessment of water quality and pollution of the Lake Seyfe basin, Kırşehir, Turkey     

Mehmet Çelik  Nail Ünsal  Osman Oğuz Tüfenkçi  Sevil Bolat 《Environmental Geology》2008,55(3):559-569

Lake Seyfe is located in a closed basin near K?r?ehir in the central Anatolian region, Turkey. The aim of this study is to evaluate the groundwater quality and effects of lithogenic contamination carried out in the Lake Seyfe basin, which is represented by various lithologies and groundwater types. Seyfe, Horla and Akp?nar springs are recharged through marbles at the western and southwestern of the basin are ultimately and discharged into the K?z?l?rmak Formation and Lake Seyfe. The waters of deep wells drilled into the marbles are of bicarbonate type (type I) in the Ca²⁺–Mg²⁺–HCO₃ ^? and Ca²⁺–HCO₃ ^? facies. Özlühüyük spring and waters from most of trenches and shallow wells, which are fed by the K?z?l?rmak Formation, have a mixed (type II) composition in the Ca²⁺–Mg²⁺–HCO₃ ^?–Cl^? facies. Groundwater in the alluvium and K?z?l?rmak Formation along Lake Seyfe has a salty (type III) character in the Na⁺–Cl^? facies. The main reasons of formation and change of the groundwater salinity and hydrochemical facies in the Seyfe basin are causing the various (a) lithogenic pollution and heterogeneity of the K?z?l?rmak Formation, (b) salinity of the upper soil zones, and (c) evaporation of the trench and channel waters open to the atmosphere. Considering parameters such as sodium hazard, specific conductivity, bicarbonate and carbonate hazards, waters in the study area are generally suitable for agricultural usage.  相似文献   

Geochemical assessment of mineral scaling in Kızıldere geothermal field,Turkey     

Gültekin Tarcan  Tuğbanur Özen  Ünsal Gemici  Mümtaz Çolak  İsmail Hakkı Karamanderesi 《Environmental Earth Sciences》2016,75(19):1317

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A multi‐dating approach applied to proglacial sediments attributed to the Most Extensive Glaciation of the Swiss Alps     

ANDREAS DEHNERT  FRANK PREUSSER  JAN D. KRAMERS  NAKI AKÇAR  PETER W. KUBIK  REGINA REBER  CHRISTIAN SCHLÜCHTER 《Boreas: An International Journal of Quaternary Research》2010,39(3):620-632

Dehnert, A., Preusser, F., Kramers, J. D., Akçar, N., Kubik, P. W., Reber, R. & Schlüchter, C. 2010: A multi‐dating approach applied to proglacial sediments attributed to the Most Extensive Glaciation of the Swiss Alps. Boreas, Vol. 39, pp. 620–632. 10.1111/j.1502‐3885.2010.00146.x. ISSN 0300‐9483. The number and the timing of Quaternary glaciations of the Alps are poorly constrained and, in particular, the age of the Most Extensive Glaciation (MEG) in Switzerland remains controversial. This ice advance has previously been tentatively correlated with the Riss Glaciation of the classical alpine stratigraphy and with Marine Isotope Stage (MIS) 6 (186–127 ka). An alternative interpretation, based on pollen analysis and stratigraphic correlations, places the MEG further back in the Quaternary, with an age equivalent to MIS 12 (474–427 ka), or even older. To re‐evaluate this issue in the Swiss glaciation history, a multi‐dating approach was applied to proglacial deltaic ‘Höhenschotter’ deposits in locations outside the ice extent of the Last Glacial Maximum. Results of U/Th and luminescence dating suggest a correlation of the investigated deposits with MIS 6 and hence with the Riss Glaciation. Cosmogenic burial dating suffered from large measurement uncertainties and unusually high ²⁶Al/¹⁰Be ratios and did not provide robust age estimates.  相似文献   

Glaciations and paleoclimate of Mount Erciyes,central Turkey,since the Last Glacial Maximum,inferred from 36Cl cosmogenic dating and glacier modeling     

Mehmet Akif Sarıkaya  Marek Zreda  Attila Çiner 《Quaternary Science Reviews》2009,28(23-24):2326-2341

Forty-four boulders from moraines in two glacial valleys of Mount Erciyes (38.53°N, 35.45°E, 3917 m), central Turkey, dated with cosmogenic chlorine-36 (³⁶Cl), indicate four periods of glacial activity in the past 22 ka (1 ka = 1000 calendar years). Last Glacial Maximum (LGM) glaciers were the most extensive, reaching 6 km in length and descending to an altitude of 2150 m above sea level. These glaciers started retreating 21.3 ± 0.9 ka (1σ) ago. They readvanced and retreated by 14.6 ± 1.2 ka ago (Lateglacial), and again by 9.3 ± 0.5 ka ago (Early Holocene). The latest advance took place 3.8 ± 0.4 ka ago (Late Holocene). Using glacier modeling together with paleoclimate proxy data from the region, we reconstructed the paleoclimate at these four discrete times. The results show that LGM climate was 8–11 °C colder than today and moisture levels were somewhat similar to modern values, with a range between 20% more and 25% less than today. The analysis of Lateglacial advance suggests that the climate was colder by 4.5–6.4 °C based on up to 1.5 times wetter conditions. The Early Holocene was 2.1–4.9 °C colder and up to twice as wet as today, while the Late Holocene was 2.4–3 °C colder and its precipitation amounts approached to similar conditions as today. Our paleoclimate reconstructions show a general trend of warming for the last 22 ka, and an increase of moisture until Early Holocene, and a decrease after that time. The recent glacier terminates at 3450 m on the northwest side of the mountain. It is a remnant from the last advance (possibly during the Little Ice Age). Repeated measurements of glacier length between 1902 and 2008 reveal a retreat rate of 4.2 m per year, which corresponds to a warming rate of 0.9–1.2 °C per century.  相似文献   

Statistical approaches to evaluate the aquatic ecosystem qualities of a significant mining area: Emet stream basin (Turkey)     

Cem Tokatli  Arzu Çiçek  Özgür Emiroğlu  Naime Arslan  Esengül Köse  Hayri Dayioğlu 《Environmental Earth Sciences》2014,71(5):2185-2197

Emet Stream is one of the most important branches of Uluabat Lake (Ramsar area) and also one of Turkey’s most important river systems. In addition to the geologic structure of the basin, Harmancik Chromium Mines are one of the most important inorganic pollution sources for the basin and also for Uluabat Lake. In the present study, water, sediment and fish (Squalius cii, Capoeta tinca and Barbus oligolepis) samples were collected seasonally from eight stations (one of them was on the Kinik Stream where the Harmancik Chromium Mines is located on and one of them was on the Dursunbey Stream) on the Emet Stream Basin. Some limnological parameters (pH, conductivity and total hardness) in water and Cr, Ca, Mg, Ni and Mn levels in biotic (muscle, gill, liver and kidney tissues of fishes) and abiotic (water and sediment) components of basin were determined to evaluate the effects of Harmancik Chromium Mines on the system. Cluster Analysis, Factor Analysis, Pearson Correlation Index, One Way Anova Tests, Scatter dot Comparing and Matrix plot Distribution Diagrams were applied to the results in order to estimate the data properly. Water samples were evaluated according to the water quality criteria for Turkey and sediment samples were evaluated according to the sediment quality criteria. According to data obtained, statistically significance differences were identified between Kinik and Emet Streams according to Cr and Ni accumulations in water and sediment. Chromium levels of Kinik Stream were extremely higher an average of 153 times for water and 10 times for sediment than uncontaminated stations. Water and sediment quality of Emet Stream were decreasing after falling the Kinik Stream and increasing after falling the Dursunbey Stream. It was also determined that, the amount of chromium in muscle tissues of three fish species were much higher than the limit value of 0.15 mg kg^?1 that FAO identified.  相似文献   

Hydrogeochemical and isotopic characteristics of the Ilica geothermal system (Erzurum,Turkey)   总被引：1，自引：0，他引：1  

Arzu Firat Ersoy  Serap Çalik Sönmez 《Environmental Earth Sciences》2014,72(11):4451-4462

In this paper, the hydrochemical isotopic characteristics of samples collected from geothermal springs in the Ilica geothermal field, Eastern Anatolia of Turkey, are examined and described. Low-temperature geothermal system of Ilica (Erzurum, Turkey) located along the Eastern Anatolian fault zone was investigated for hydrogeochemical and isotopic characteristics. The study of ionic and isotopic contents shows that the thermal water of Ilica is mainly, locally fed by groundwater, which changes chemically and isotopically during its circulation within the major fault zone reaching depths. The thermal spring has a temperature of 29–39 °C, with electrical conductivity ranging from 4,000 to 7,510 µS/cm and the thermal water is of Na–HCO₃–Cl water type. The chemical geothermometers applied in the Ilica geothermal waters yielded a maximum reservoir temperature of 142 °C according to the silica geothermometers. The thermal waters are undersaturated with respect to gypsum, anhydrite and halite, and oversaturated with respect to dolomite. The dolomite mineral possibly caused scaling when obtaining the thermal waters in the study area. According to the enthalpy chloride-mixing model, cold water to the thermal water-mixing ratio is changing between 69.8 and 75 %. The δ¹⁸O–δ²H compositions obviously indicate meteoric origin of the waters. Thermal water springs derived from continental precipitation falling on to higher elevations in the study area. The δ¹³C ratio for dissolved inorganic carbonate in the waters lies between 4.63 and 6.48 ‰. In low-temperature waters carbon is considered as originating from volcanic (mantle) CO₂.  相似文献   

A hybrid representation for modeling,interactive editing,and real-time visualization of terrains with volumetric features     

Çetin Koca 《International journal of geographical information science》2014,28(9):1821-1847

Terrain rendering is a crucial part of many real-time applications. The easiest way to process and visualize terrain data in real time is to constrain the terrain model in several ways. This decreases the amount of data to be processed and the amount of processing power needed, but at the cost of expressivity and the ability to create complex terrains. The most popular terrain representation is a regular 2D grid, where the vertices are displaced in a third dimension by a displacement map, called a heightmap. This is the simplest way to represent terrain, and although it allows fast processing, it cannot model terrains with volumetric features. Volumetric approaches sample the 3D space by subdividing it into a 3D grid and represent the terrain as occupied voxels. They can represent volumetric features but they require computationally intensive algorithms for rendering, and their memory requirements are high. We propose a novel representation that combines the voxel and heightmap approaches, and is expressive enough to allow creating terrains with caves, overhangs, cliffs, and arches, and efficient enough to allow terrain editing, deformations, and rendering in real time.  相似文献   

Comments on “Monitoring soil erosion in Cappadocia region (Selime–Aksaray–Turkey)” by Yilmaz et al. (Environ Earth Sci 2012, 66:75–81)     

Attila Çiner  Mehmet Akif Sarıkaya  Erkan Aydar 《Environmental Earth Sciences》2013,70(4):1927-1931

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Luminosity–colour relations for red clump stars     

S. Bilir  Ö. Önal  S. Karaali  A. Cabrera-Lavers  H. Çakmak 《Astrophysics and Space Science》2013,344(2):417-427

We calibrated the absolute magnitudes M _V , M _J , $M_{K_{s}}$ and M _g of red clump stars in terms of colours. M _V and M _g are strongly dependent on colour, while the dependence of M _J and $M_{K_{s}}$ on colour is rather weak. The calibration of the absolute magnitudes M _V and $M_{K_{s}}$ is tested on 101 RC stars in the field SA 141. The Galactic model parameters estimated with this sample are in good agreement with earlier studies.  相似文献