Late Quaternary subsidence records from the Datça graben and Cnidus ancient city (SW Turkey): sea-level changes versus tectonics

The Datça graben in southwestern Anatolia is a WNW-trending seismically active depression, with tectonic activity since Pliocene time. This tectonic activity is controlled by normal faults, which have effected ancient settlements. The Cnidus city (old and modern) –an ancient mercantile centre during the Hellenistic, Roman and Byzantine periods– is one of the places that has recorded this activity. The ancient harbour walls of Cnidus, lying 2.2-4.0m below sea level, contain important traces about sea-level changes and tectonics over the past 2.6kyr. Palaeostress analysis along boundary faults in the Datça graben yields an almost N–S oriented pure tensional regime, compatible with earthquake focal mechanism solutions located around the Datça Peninsula. Additionally, an almost E−W trending surface rupture related to a historical earthquake in modern Cnidus, which shows normal fault characteristics, gives further support to the ongoing extension along the Kızlan, Karaköy and Cnidus fault zones. Previous studies on late Quaternary sea-level changes around the Datça Peninsula suggest that 2.6kyr ago sea level was 1.0-1.25m lower than today. From the present-day depth of the Old Cnidus harbour remains and regional sea-level records, it can be inferred that tectonics has played a significant role. Our calculations show that the Datça graben is subsiding at rates of 0.36-0.46mm/yr in the central part and 1.05-1.15mm/yr in the southern part. These values match those found in other areas around the Datça Peninsula

First record of tempestites from Quaternary lacustrine deposits in the Ağrı Basin (Eastern Anatolia, Türkiye) : palaeoclimatological and palaeogeographic implications

Several event layers have been identified in lacustrine deposits in the AErI Basin of Anatolia (E Türkiye). Sedimentological and palaeontological data newly indicate a storm-induced origin for some of them. The sedimentary structures in three sections, a few tens of metres apart from each other laterally, such as hummocky cross-stratification, wave-generated cross-bedding, parallel bedding, erosional surfaces, and graded bedding, which are considered characteristic of tempestites, are clearly present. Additionally, fining-upwards units and biogenic escape structures located at different levels of these sections indicate a similar origin. The vertical variations in layer thickness, grain size, and sedimentary structures in these sedimentary sections indicate fluctuating hydrodynamic conditions during deposition, while lateral decrease in the size and wavelength of the structures reflects deepening. This interpretation of storm-induced deposition is compatible with regional palaeoclimatological and palaeogeographical data, and is supported by evidence of Quaternary storm-induced sedimentation in adjacent lacustrine basins in the region

Seismogenic structures in Quaternary lacustrine deposits of Lake Van (eastern Turkey)

Soft-sediment deformation structures formed by liquefaction and/or fluidisation of unconsolidated sediments due to seismic shocks are frequent in the Quaternary sandy, silty and clayey deposits of Lake Van. They are present in both marginal and deep lacustrine facies. Their morphology and interpreted genesis imply that they should be considered as fluid-escape structures (dish and pillar structures, flame structures and sand volcanoes), contorted structures (simple and complex convolutions and ball-and-pillow structures) and other structures (disturbed layers and slump structures). The most recently formed structures are related to the October 23rd, 2011 Van-Tabanlı (M w 7.2) earthquake. The exist -ence of seismites at various stratigraphic levels in the lacustrine deposits is indicative of tectonic activity that frequently triggered earthquakes with magnitudes of 5 or more, affecting the Lake Van Basin

Two Dimensional Geoelectrical Structure Of Kütahya-hisarcik Geothermal Area

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2015Thesis (M.Sc.) -- İstanbul Technical University, Instıtute of Science and Technology, 2015Jeofizik yöntemlerden doğru akım elektrik özdirenç yöntemi jeolojik yapıların araştırılmasında, yanal süreksizlerin ortaya konmasında, gevşek çökel malzemenin derinliği ve kalınlığı ile sağlam temel kaya derinliğinin bulunmasında, hidrojeolojik çalışmalarda tuzlu su girişimi ve yeraltı suyu kirlilik haritalarının elde edilmesinde, doğal kaynak aramalarında, jeotermal aramalarda, cevherleşme olan bölgelerin bulunmasında tüm dünyada yaygın olarak kullanılmaktadır.   Bu çalışmada MTA tarafından Kütahya Hisarcık jeotermal alanında gerçekleştirilen 5 profil boyunca 69 adet düşey elektrik sondaj (DES) ve 4 profil boyunca 65, 48, 43 ve 50 noktada doğal potansiyel (Self-Potential SP) ölçümlerinden elde edilen veriler değerlendirilmiş ve bölgenin iki boyutlu yeraltı yapısı araştırılmıştır. Arazide yapılan DES çalışmalarında AB/2 değerleri 1000 m. ile 2000 m. arasında değişmektedir. Bunun yanında DES profillerine dik ve paralel şekilde 4 profilde SP ölçüleri alınmıştır. DES verileri bir boyutlu, yanal kısıtlı bir boyutlu (yaklaşık 2B) ve iki boyutlu ters çözüm algoritmaları kullanılarak değerlendirilmiştir. 1B ters çözümde kullanılan Occam algoritması, yer içi özdirenç yapısının sürekli ve yumuşatılmış biçimde elde edilmesine dayanmaktadır. İyileştirmede kullanılan yinelemelerde, bir önceki RMS (root mean square) hatasından daha küçük hata veren modeller içerisinde en yumuşak özdirenç değişimini gösteren model araştırılmaktadır. Yaklaşık 2B ters çözümde, yanal kısıtlı 1B ters çözüm algoritması kullanılmaktadır. Bu algoritma, bir doğrultu boyunca ölçülen tüm verilerin iki boyutlu düzgünleyici kısıtlamalar ile yeniden düzenlenen bir boyutlu ters çözüm ile terslenmesi prensibine dayanmaktadır. Dolayısıyla bu algoritma kullanılarak 1B ve yaklaşık 2B ters çözümlerin karşılaştırılması ile iki boyutlu bozucu etkilerin belirlenmesi amaçlanmıştır ve bu çözümlerden elde edilen sonuca göre 2B ters çözüm algoritmasına verilecek başlangıç modeli belirlenmektedir. 2B Schlumberger ters çözüm algoritması, sabit tutulan blokların her yinelemede sadece özdirenç değerlerinin değiştirilmesi yöntemiyle çalışmaktadır. Elektrik özdirenç ve doğal potansiyel yöntemleri ile hesaplanan yer altı modeli ile sıcaklık ve akış modellemeleri yapılmıştır. Bu amaçla Fluent isimli program kullanılmıştır. Bulunan sonuçlar çerçevesinde araştırma alanında jeotermal alanın varlığını işaret eden kırık yapıları ve sıcak akışkan içeren rezervuarın konumu ve derinliği net bir şekilde ortaya konulmuştur.Fossil fuels such as coal, petroleum, natural gas and nuclear power are used primarily for energy production around the world. Since the global awareness increased for the detrimental effects of burning fossil fuels, clean and renewable energy sources, ie, hydroelectric, geothermal, sunlight, wind, gain more interest. Geothermal energy which has proven to be clean, renewable and safe, is one of the promising renewable energy source. Turkey is located on the Alpine-Himalayan orogenic belt and locating in region of high tectonic activity. There are Miocene or younger grabens developed in that area as a result of this orogeny. Therefore, Turkey is a country with a significant geothermal energy potential. Electricity generation, direct use (house heating, greenhouse heating) and industrial usage are some of the various geothermal energy utilizations can be done in Turkey. Resource assesment is done many times by the General Directorate of Mineral Research and Exploration (MTA) and today it is discovered more than 1000 hot and mineral water springs which their temperature is up to 100-140 oC and geothermal fields with a temperature range of 40-232 oC. 95 percent of the discovered 186 geothermal field is low-medium enthalpy source. Although Turkey is the 7th richest country in the word in terms of geothermal potential, most of the development has been achieved at direct-use applications. Exploration of geothermal fields are in great importance since it is a cleaner energy source. For this purpose, direct current geophysical method is a well suited tool for geothermal exploration and for all that, geological structures, lateral discontinuities, sediment thickness and depth, bedrock depth, hydrogeologic studies, groundwater exploration and groundwater contamination and natural resources. In this study, it is aimed to obtain two dimensional subsurface structure of Kütahya-Hisarcık geothermal field. Detailed geophysical survey which consist of 69 vertical electrical soundings (VES) with various AB/2 between 1000 m. and 2000 m. and SP measurements of 4 profile were carried out by MTA. Schlumberger electrode spacing is used for VES surveys and 25 m. electrode spacing is used for SP profiling. Study area is located north of Emet-Gediz graben. Measurements took place at a 69 km2 area near Hamamköy and Sefaköy and can be located at 1/25000 scaled Kütahya J22-c1 map. Survey area is located at 70 km. south-west of Kütahya centrum and 10 km. south of Emet. Fault directions are observed in vicinity are, NW-SE, N-S and NE-SW. While right lateral faults are NW-SE oriented, N-S and NESw oriented ones are dip-slip normal faults. Most important tectonic element is Hisarcık fault. This fault is N-S oriented and observed in Neogene Yeniköy formation. Yeniköy formation consists of sandstone, siltstone, marl and fine grained sandstone-tuff layers. Travertines are observed in a small area north of Hamamköy. Budağan limestones, Arıkaya and Sarıcasu formations underlaying the Yeniköy formation are potential geothermal reservoirs. VES data are inverted by 1D, quasi 2D and 2D inversion algorithms. Occam algorithm is used for 1D inversion which gave a smooth and continuous resistivity variations of the area. It is more satisfactory to allow the model to be as flexible as possible but suppress complexity explicitly. Therefore a rougness value is defined. Goal here is to find the smallest roughness value that agrees with the measurements.  In order to convert the VES data by quasi 2D, laterally constrained 1D (LCI) algorithm is used. This algorithm uses similar approach that Occam does and based on applying modified one dimensional inversion with two dimensional smoothness constraints on a vertical electrical sounding data along a line. Therefore this quasi 2D algorithm is compared with 2D inversion  to determine 2D structural effects. Lastly, 2D Schlumberger inversion algorithm is used which based on 2D model with fixed block boundaries during inversion and only the resistivity values of each block changes through the iteration. VES data inverted along 5 profiles which are all parallel to each other are named I, J, JK, K and M in respect to north to south. There is a high-low resistivity contrast at northern profiles. The reason for this contrast is thought of Hisarcık fault at vicinity. This boundary is located near I-18 VES station divides the area into two zones with 400 ohm-m.- 20 ohm-m. resistivity difference. East of I-18, there is a remnant of old depression around I-23. According to geoelectrical structure of profile I, bedrock gets deeper eastwards. Low resistivity zone is seen around 1500 m. along profile and at a depth of 750-800 m. Hisarcık fault is also seen at Profile J with its characteristic high resistivity contrast. Low resistivity (less than 10 Ω m.) is 1200-1600 m. along profile and at 400 m. depth. Horst-graben structure is clearly seen at profile J around JK-18 – JK-19 and JK-23 – JK-24. Area between these two faults are between 1300 m. and 1800m.  along profil J and between 400 – 600 m. depth. Faults observed at other profiles also seen clearly at profile K around K-18 – K-19 ves stations. Graben structure seen around K-20-1 – K-21 stations and low resistivity zone is located at a depth of 400-675 m. Profile M is the longest profile and located at the south of other profiles. Old depression mentioned at profile I is also shown at this profile between M-20 – M-27 VES stations. East and west of this depression, graben structure is visible clearly. Area is characterize with Pliocene allüvial deposits and Hisarcık formation and Miocene aged Yeniköy formation at the uppermost layer. These formations are underlayed by fructured Arıkaya and Balıkbaşı limestones. It is thought that Simav metamorfics are the bottom layer at vicinity.  There are 4 SP profiles consist of 65, 48, 43 and 50 stations are named A,B,C and D. A and B profiles are parallel to each other and perpendiculat to VES profiles. C profile is between I-19 and I-23 VES stations. Profile D is intercepts I, J, JK and K VES profiles. Both profiles B and A are shown similar characteristics as continuous increase or decrease. This indicates that these profiles are along the geological structures and does not intercepts a fault surface. On the other hand, profile C shows negative values between I-21 and I-22. These results concur with the graben structure observed at VES cross sections.   In order to find the reservoir’s location and depth, fault and fracture structures derived from VES and SP data are used in ANSYS FLUENT 6.3.26 computational fluid dynamics software. This software operates using finite volume method for flow and temperature modelling. Temperature, porosity, permeability, viscosity, heat capacity, thermal expansion coefficient and thermal conductivity are used as model parameters for modelling. These parameters were conbined wth the subsurface geometries derived from SP and VES studies in order to build mesh geometry. Model consist of 40710 finite volume element and 41370 nodes that binds them. Fault zones are defined by permeability contrast within surrounding rocks. While surrounding rocks have a permeability of 10-15, fault zones are defined with 10-13.  Model parameters are decided after thorough literature research and concurs with recent studies. Steady state temperature calculations shows that smooth temperature curves. This is in agreement with the expected heat conduction (less Rayleigh number than Critical Rayleigh number). Furthermore, 10-9 m/s Darcy velocities are observed around fault zones. This is velocity values are also concur with recent studies.    Temperature of Yenice, Yoncaağaç and Sefaköy hotsprings at Emet-Hisarcık graben are measured as 37 oC, 49 oC and 51 oC. According to this information, temperatures of the hotsprings are increasing from north to south. This also in agreement with the VES cross sections that indicates deepening bedrock through eastwards. Therefore it is possible to obtain higher temperature reservoirs and further investigations are needed.Yüksek LisansM.Sc

Stokiyometrik Olmayan Oksitler Kullanılarak Hidrojen Üretim Süreç ve Teknolojilerinin Geliştirilmesi

TÜBİTAK MAG Proje15.10.2016Projenin ana hedefi stokiyometrik olmayan metal oksitler üzerinde H2O moleküllerininkırılması ile ilave saflaştırma süreçlerine gerek duyulmaksızın yüksek saflıkta, ekonomik H2üretimidir. Bu kırılma reaksiyonu için gerekli yüksek sıcaklıklar güneş ışınlarının odaklanmasıile sağlanacaktır. Bu yaklaşımın günümüz fosil yakıt kaynaklı H2 üretim süreçleri ile rekabetedebilir olması için üretim maliyetlerinin kilogram H2 başına 3.5$mertebesinde olmasıhedeflenmiştir. Bu proje ile Türkiye?nin enerji ve endüstriyel hammadde üretiminde fosilyakıtlara ve dolayısıyla yabancı kaynaklara olan bağımlılığının azaltılmasına katkıdabulunmayı amaçlıyoruz.Bu hedef doğrultusunda yürütülen deneysel ve teorik çalışmalar sonrasında Mullit monolitüzerine kaplanmış Pd-CeO2 ve SiC köpük monolit üzerine kaplanmış Pt-Co3O4 katalizörmalzemelerin söz konusu sürecin ekonomik bir şekilde sürdürülebilmesi yolunda gelecekvaad ettiği sonucuna ulaşılmıştır. Bu çalışmalara ek olarak güneş ışığı odaklanması ve takibikonularında ciddi bilgi birikimi elde edilmiştir.This proposal is aimed at demonstrating the possible cost reduction of H 2 production usingsolar irradiation to achieve the H 2 O cracking temperatures over non-stoichiometric oxidecatalysts. In specific we are targeting a unit production cost of at most 3.5$ per kilogram ofH 2 produced, to become cost competitive compared to conventional H 2 productiontechnologies based on fossil fuels. The main motivation for this particular choice of theobjective is to be able to contribute to the reduction of dependence on fossil fuels for energyand industrial raw materials.The experimental and modeling activities carried our in accordance to these objectives haveresulted in two material pairs that are promising in achieving the ultimate project objectives.These are mullet monolits coated with Pd loaded CeO 2 and Pt loaded Co 3 O 4 coated on SiCfoams. In addition to these fundamental learnings, significant know-how has beenaccumulated regarding the tracking and concentration of solar irradiation. Work is still on-going to merge these two areas and demonstrate pilot scale production of H 2 through watersplitting using these material pairs assisted with solar energy