AYBE- İklim ve Deniz Bilimleri Lisansüstü Programı

Bu topluluk için Kalıcı Uri

http://hdl.handle.net/11527/263

Bu anabilim dalımızda fizik, meteoroloji, çevre gibi farklı disiplinlerden gelen öğrencilere çok sayıda Yüksek Lisans ve Doktora çalışmaları yaptırılmıştır. Çalışma Konuları: • İklim Değişikliği • İklim Modellemesi • Hidrolojik Modelleme • Hava Kalitesi Modellemesi • Model Performans Değerlendirmesi • Atmosfer - Okyanus Etkileşimi • Emisyon Envanteri • Türkiye İklimi

Gözat

Simulation Of 137cs Transport And Deposition After The Chernobyl Nuclear Power Plant Accident And Radiological Doses Over The Anatolian Peninsula

(Eurasia Institute of Earth Sciences, 2014-11-25) Şimşek, Volkan ; Kındap, Tayfun ; 601062006 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri

The Chernobyl Nuclear Power Plant (CNPP) accident occurred on April 26 of 1986, was the most serious accident ever to occur in the nuclear power industry. It is still an episode of interest, due to the large amount of radionuclides dispersed in the atmosphere. After CNPP accident main releases occurred during first 10 days of the accident. From the radiological point of view, the releases of 131I and 137Cs, estimated to have been 1,760 and 85 PBq, respectively, are the most important to consider. Caesium-137 (137Cs) is one of the main radionuclides emitted during the Chernobyl accident, can travel long distances in the air before being brought back to the earth by rainfall and gravitational settling It has a half-life of 30 years, which can be accumulated in humans and animals, and for this reason the impacts on population are still monitored today. One of the main parameters in order to estimate the exposure of population to 137Cs is the concentration in the air, during the days after the accident, and the deposition at surface. The transport and deposition of 137Cs over Europe occurred after the CNPP accident has been simulated using the WRF-HYSPLIT modelling system. The model simulations could reproduce fairly well the observations of 137Cs concentrations and deposition, which were used to generate the 'Atlas of caesium deposition on Europe after the Chernobyl accident' and published in 1998. We estimated a total deposition of 2-3.5 PBq over Turkey. Air concentrations values reached 25 Bq/m3 in the province of Edirne Estimated doses reached up to 0.15 mSv/year in the North Eastern part of Turkey even if the contribution from ingestion of contaminated food and water is not considered, the estimated levels are largely below the 1 mSv limit indicated by the International Commission on Radiological Protection.
Bir Zebra Midyesi (dreissena Polymorpha) İstilasının Mekansal Ve Zamansal Örüntüleri

(Eurasia Institute of Earth Sciences, 2015-01-19) Kanmaz, Oğuzhan ; Dalfes, Hasan Nüzhet ; 601111005 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Biological invasions are an important dimension of global change and is an environmental problem which has a serious consequences. Awareness about this issue has increased, especially after the invasion of zebra mussels in Great Lakes of North America and environmental and economic results of this invasion. In this study, spatial and temporal patterns of the zebra mussel invasion in Great Lakes was studied, for a 20-year period by using individual based modelling method. The model was developed in NetLogo environment. Numerical experiments were also conducted in this environment. First of six experiment sets is reference case experiment. Effects of phytoplankton density on zebra mussel populations were investigated in P75 and P125 experiment sets. In T0.1 and T10 experiment sets, effects of transportation probability on zebra mussels were investigated. Last experiment set, SupD, was conducted to observe how environmental changes would affect a biological invasion, by applying Lake Huron conditions to Lake Superior. According to results, there is no linear relation between the change of phytoplankton amount and the increase of zebra mussel population and slight changes of phytoplankton amount cause significant increases in invasion strenght. Changes in transportation probability, affect invasion stages temporally and also have impact on population size. SupD experiment results show that probable climate changes have a strengthening effect on biological invasions. Results also show that, lake location in the waterbody network is also important beside the individual conditions of each lake and mussel populations constitute characteristic patterns depending on invasion strenght.
Üniversite Öğrencilerinin Biyoçeşitlilik Algısı Ve Biyoçeşitlilikle İlgili Tutumlarının Analizi

(Eurasia Institute of Earth Sciences, 2015-01-19) Şenel, Tuğçe ; Dalfes, Hasan Nüzhet ; 601111006 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Turkey has a very rich biodiversity yet this enourmous richness is seriously under threat. Lack of nature education leads conservation acts and campaigns to be under supported and even rejected by people. To have a sufficient nature education is very important for young population, who are scientists, engineers, decision makers, law makers...etc. of the future. In Turkey, nature education basically consists of biology courses. In this study, two hundred higher education students were asked to participate in a twelve item questionnaire about biodiversity. Their perception and attitudes towards biodiversity were investigated. Results show that although the students know what biodiversity is and they are sensitive about environmental issues they have many confusions, misconceptions and lack of knowledge. Results also underline that, a well planned, early starting nature education which families also will be a part of it is required and this education should be seperated from biology courses and be a life long learning process.
Türkiye'de İklim Uç Olayları İndislerinin Tarihsel Değişimi

(Eurasia Institute of Earth Sciences, 2015-01-20) Dündar, Berna ; Şen, Ömer Lütfi ; 601111003 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

The climate system has a profound effect on life on the Earth. People's daily life mainly depends on weather that surrounds them. Besides, wheather and climate extremes have significant influence on society, environment and the economy. Hence, it is very important to study them. ETCCDI defined 27 core indices for investigating extreme events. In this study 14 indices from them has been analysed. Daily temperature and precipitation data for 452 stations, obtained from Turkish State Metereological Service. In order to eliminate stations with missing values, data visualization method used and 134 stations selected from 452 stations. These data were used for trend analysis of these indices between the periods 1965 – 2006. The Sequentiall Mann Kendall non-parametric test applied for trend analysis of the indices. This version of the Mann Kendall test used to determine the beginning of a trend within a sample. Firstly, in this study annual maximum and minimum temperature trends examined for four months that were October, May, January and July. In addition, their annual precipitation investigation have been done. According to this examination, annual maximum temperatures of July', October and May showed increasing trends whereas there was not any spatially coherent trend observed for January. Annual minimum temperature investigation revealed that for July' there was spatially coherent increasing trend throughout the country. In contrast, just one station indicated decreasing trend that was Erzurum. Moreover, the same behavior observed for October' annual minimum temperatures also. Annual minimum temperatures for May' indicate both increasing and decreasing trends for some stations. There was not any annual precipitation pattern found for these months. Secondly, trend analysis of 14 indices studied. According to this analysis, there was no spatially coherent increasing or decreasing trend for "number of frost days", though the few stations that indicate increasing behaviour were mainly in the northern half of the country. On the other hand, "numbers of summer days" have been increasing in Turkey; and the significant increases distributed throughout the country with the exception of Southeastern Anatolia region. For "tropical nights", stations located around the Marmara Sea, Mediterranean coastal areas and northeast of the country showed increasing trends. There weren't any trends observed for "growing season length" and "icing days". Trend analysis of monthly maximum temperatures of daily maximum and minimum, monthly minimum temperatures of daily maximum and minimum have been done for January and July. No trends observed for January. However, there was an increasing trend for monthly maximum value of daily minimum temperatures of July. This trend observed along coastal areas, especially Aegean and Mediterranean regions and some stations around Marmara Sea. Furthermore, a few stations on the Black Sea coastline and some inland stations showed this behavior also. Trend analysis of monthly minimum value of daily maximum temperature of July indicated an increasing trend along the Mediterranean and Aegean coastlines. Besides, the same behavior observed at some stations located in the Southeast, Central Anatolia and northeast of the Black Sea Region. Trend analysis of monthly minimum value of daily minimum temperature of July showed an increasing trend along the Mediterranean, Aegean coastlines and some stations around Marmara Sea. Moreover, some stations in the west, central and northern part of the country. Trend analyses of daily temperature range done for January and July. For January, there wasn't any spatially coherent trends observed; some stations showed decreasing; some Aegean coastline and inland stations indicated increasing trend. Trend analyses of July showed that stations mainly in the northern part of the country indicated increasing trend wheras some stations located in the Mediterraean coastal areas and southeast and east part of the country showed decreasing behavior. Trend analyses of precipitation indices were done as well. However, there wasn't any trend observed for monthly maximum 1-day precipitation, also monthly maximum consecutive 5-day precipitation. Moreover, no trend observed for R10mm (annual count of days when precipitation ≥ 10 mm) and R20mm. In this study, 134 stations annual maximum and minimum temperature and precipitation data have been analysed for the period 1965-2006. In addition, 14 climate extreme indices trends have been investigated for the same period. Consequences from this research revealed that; annual maximum temperature of July, October and May indicated increasing trends. Besides, annual minimum temperature of July and October showed increasing tendency throughout the country. However, there wasn't any precipitation pattern found for Turkey. In addition, increasing trend observed for number of summer days and tropical nights whereas there weren't any spatially coherent trends observed for growing season length and icing days. Monthly maximum and minimum temperatures displayed increasing trend for July. However, no trends observed for January. Hence, it may infer that the effect of climate change on Turkey is more obvious in the warmer part of the year.
Hersiniyen Orojenik Sisteminin Doğu Avrupadaki Kısmının Geometrisi, Evrimi Ve İskititlere Geçişi

(Eurasia Institute of Earth Sciences, 2015-07-12) Sağdıç, Nurbike Göksu ; Şengör, Ali Mehmet Celal ; 601121004 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

The Hercynian Orogen, one of the best-known orogenic belts in the world, still hides many secrets concerning its evolution. This orogen formed through the collision between Laurussia and Gondwana-Land, which resulted in the supercontinent of Pangaea. Pangaea's formation began in the late Devonian with the onset of subduction and continued from the early-medial Carboniferous to the Permo-Triassic by means of collision. However, at the eastern part of this supercontinent, collision never happened and subduction continued in the Permo-Triassic. The coast of the Palaeo-Tethys known as Alpine-type Triassic succession was the scene of high mobility events in the core of the Pangaea in terms of Hercynian and Post-Hercynian stages. It is a fact that when the subduction process was still continuing, a rifting event began in the Permo Triassic at the eastern part of Pangaea by disrupting a magmatic arc. The results show a continuous arc goes from the Rhodope-Pontide Fragment in the north, through the Eastern Carpathians, Tisza Block, Western Carpathians, and Pelagonian Zone, to the Eastern Pontides in the south. Additionally, the lithostratigraphic charts of all the tectonic zones indicate the volcano sedimentary complexes, which show a rifting event as their most likely interpretation. As a consequence of this rifting, a marginal basin started to form beginning from the eastern part and tore westward by tracing the weak zones of the former arc. It began to take shape from the Karakaya Complex, goes through the Pelagonian zone and the Inner Western Carpathians namely Meliaticum into the Tisza Block in the Late Permian-Early Triassic. From the medial to the end of the late Triassic, the entire Hellenic-Dinaric System and Italy began to disintegrate, which started from the Pindos Zone in Hellenides and Sicily in Italy, and joined together into the Southern Alps by passing through all along the coast of the present Adriatic Sea. This presentation shows a reconstruction of the Mediterranean Tethysides at the time of the early Triassic. It was done by palinspastically restoring all the orogenic deformation for which data were to be had painstakingly and not just schematically. It is still incomplete, because it does not show the rift areas of the Sclafani-Imerese, Lagonegro and Pindos-Budva, except to show where they were. It also delineates the lie of the Karakaya and the Meliata rifts and shows that they were one and the same rift. Karakaya was later partly incorporated into the Vardar Ocean. Most of it closed during the earliest Jurassic, whereas the Meliata part was delayed until the late Jurassic. These closures are responses to two events: 1) Palaeo-Tethyan closure in case of Karakaya and 2) the opening of the South Atlantic in case of the Meliata. This paper addresses itself mainly to the solution of the Karakaya-Meliata problem.
Pre-collisional Accretion And Exhumation Along The Southern Laurasian Active Margin, Central Pontides, Turkey

(Eurasia Institute of Earth Sciences, 2015-11-25) Aygül, Mesut ; Okay, Aral ; 601092002 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri

The Central Pontides is an accretionary-type orogenic area within the Alpine-Himalayan orogenic belt characterized by pre-collisional tectonic continental growth. The region comprises Mesozoic subduction-accretionary complexes and an accreted intra-oceanic arc that are sandwiched between the Laurasian active continental margin and Gondwana-derived the Kırşehir Block. The subduction-accretion complexes mainly consist of an Albian-Turonian accretionary wedge representing the Laurasian active continental margin. To the north, the wedge consists of slate/phyllite and metasandstone intercalation with recrystallized limestone, Na-amphibole-bearing metabasite (PT= 7–12 kbar and 400 ± 70 ºC) and tectonic slices of serpentinite representing accreted distal part of a large Lower Cretaceous submarine turbidite fan deposited on the Laurasian active continental margin that was subsequently accreted and metamorphosed. Raman spectra of carbonaceous material (RSCM) of the metapelitic rocks revealed that the metaflysch sequence consists of metamorphic packets with distinct peak metamorphic temperatures. The majority of the metapelites are low-temperature (ca. 330 °C) slates characterized by lack of differentiation of the graphite (G) and D2 defect bands. They possibly represent offscraped distal turbidites along the toe of the Albian accretionary wedge. The rest are phyllites that are characterized by slightly pronounced G band with D2 defect band occurring on its shoulder. Peak metamorphic temperatures of these phyllites are constrained to 370-385 °C. The phyllites are associated with a strip of incipient blueschist facies metabasites which are found as slivers within the offscraped distal turbidites. They possibly represent underplated continental metasediments together with oceanic crustal basalt along the basal décollement. Tectonic emplacement of the underplated rocks into the offscraped distal turbidites was possibly achieved by out-of-sequence thrusting causing tectonic thickening and uplift of the wedge. 40Ar/39Ar phengite ages from the phyllites are ca. 100 Ma, indicating Albian subduction and regional HP metamorphism. The accreted continental metasediments are underlain by HP/LT metamorphic rocks of oceanic origin along an extensional shear zone. The oceanic metamorphic sequence mainly comprises tectonically thickened deep-seated eclogite to blueschist facies metabasites and micaschists. In the studied area, metabasites are epidote-blueschists locally with garnet (PT= 17 ± 1 kbar and 500 ± 40 °C). Lawsonite-blueschists are exposed as blocks along the extensional shear zone (PT= 14 ± 2 kbar and 370–440 °C). They are possibly associated with low shear stress regime of the initial stage of convergence. Close to the shear zone, the footwall micaschists consist of quartz, phengite, paragonite, chlorite, rutile with syn-kinematic albite porphyroblast formed by pervasive shearing during exhumation. These types of micaschists are tourmaline-bearing and their retrograde nature suggests high-fluid flux along shear zones. Peak metamorphic mineral assemblages are partly preserved in the chloritoid-micaschist farther away from the shear zone representing the zero strain domains during exhumation. Three peak metamorphic assemblages are identified and their PT conditions are constrained by pseudosections produced by Theriak-Domino and by Raman spectra of carbonaceous material: 1) garnet-chloritoid-glaucophane with lawsonite pseudomorphs (P= 17.5 ± 1 kbar, T: 390-450 °C) 2) chloritoid with glaucophane pseudomorphs (P= 16-18 kbar, T: 475 ± 40 °C) and 3) relatively high-Mg chloritoid (17%) with jadeite pseudomorphs (P= 22-25 kbar; T: 440 ± 30 °C) in addition to phengite, paragonite, quartz, chlorite, rutile and apatite. The last mineral assemblage is interpreted as transformation of the chloritoid + glaucophane assemblage to chloritoid + jadeite paragenesis with increasing pressure. Absence of tourmaline suggests that the chloritoid-micaschist did not interact with B-rich fluids during zero strain exhumation. 40Ar/39Ar phengite age of a pervasively sheared footwall micaschist is constrained to 100.6 ± 1.3 Ma and that of a chloritoid-micaschist is constrained to 91.8 ± 1.8 Ma suggesting exhumation during on-going subduction with a southward younging of the basal accretion and the regional metamorphism. To the south, accretionary wedge consists of blueschist and greenschist facies metabasite, marble and volcanogenic metasediment intercalation. 40Ar/39Ar phengite dating reveals that this part of the wedge is of Middle Jurassic age partly overprinted during the Albian. Emplacement of the Middle Jurassic subduction-accretion complexes is possibly associated with obliquity of the Albian convergence. Peak metamorphic assemblages and PT estimates of the deep-seated oceanic metamorphic sequence suggest tectonic stacking within wedge with different depths of burial. Coupling and exhumation of the distinct metamorphic slices are controlled by decompression of the wedge possibly along a retreating slab. Structurally, decompression of the wedge is evident by an extensional shear zone and the footwall micaschists with syn-kinematic albite porphyroblasts. Post-kinematic garnets with increasing grossular content and pseudomorphing minerals within the chloritoid-micaschists also support decompression model without an extra heating. Thickening of subduction-accretionary complexes is attributed to i) significant amount of clastic sediment supply from the overriding continental domain and ii) deep level basal underplating by propagation of the décollement along a retreating slab. Underplating by basal décollement propagation and subsequent exhumation of the deep-seated subduction-accretion complexes are connected and controlled by slab rollback creating a necessary space for progressive basal accretion along the plate interface and extension of the wedge above for exhumation of the tectonically thickened metamorphic sequences. This might be the most common mechanism of the tectonic thickening and subsequent exhumation of deep-seated HP/LT subduction-accretion complexes. To the south, the Albian-Turonian accretionary wedge structurally overlies a low-grade volcanic arc sequence consisting of low-grade metavolcanic rocks and overlying metasedimentary succession is exposed north of the İzmir-Ankara-Erzincan suture (İAES), separating Laurasia from Gondwana-derived terranes. The metavolcanic rocks mainly consist of basaltic andesite/andesite and mafic cognate xenolith-bearing rhyolite with their pyroclastic equivalents, which are interbedded with recrystallized pelagic limestone and chert. The metavolcanic rocks are stratigraphically overlain by recrystallized micritic limestone with rare volcanogenic metaclastic rocks. Two groups can be identified based on trace and rare earth element characteristics. The first group consists of basaltic andesite/andesite (BA1) and rhyolite with abundant cognate gabbroic xenoliths. It is characterized by relative enrichment of LREE with respect to HREE. The rocks are enriched in fluid mobile LILE, and strongly depleted in Ti and P reflecting fractionation of Fe-Ti oxides and apatite, which are found in the mafic cognate xenoliths. Abundant cognate gabbroic xenoliths and identical trace and rare earth elements compositions suggest that rhyolites and basaltic andesites/andesites (BA1) are cogenetic and felsic rocks were derived from a common mafic parental magma by fractional crystallization and accumulation processes. The second group consists only of basaltic andesites (BA2) with flat REE pattern resembling island arc tholeiites. Although enriched in LILE, this group is not depleted in Ti or P. Geochemistry of the metavolcanic rocks indicates supra-subduction volcanism evidenced by depletion of HFSE and enrichment of LILE. The arc sequence is sandwiched between an Albian-Turonian subduction-accretionary complex representing the Laurasian active margin and an ophiolitic mélange. Absence of continent derived detritus in the arc sequence and its tectonic setting in a wide Cretaceous accretionary complex suggest that the Kösdağ Arc was intra-oceanic. This is in accordance with basaltic andesites (BA2) with island arc tholeiite REE pattern. Zircons from two metarhyolite samples give Late Cretaceous (93.8 ± 1.9 and 94.4 ± 1.9 Ma) U/Pb ages. Low-grade regional metamorphism of the intra-oceanic arc sequence is constrained 69.9 ± 0.4 Ma by 40Ar/39Ar dating on metamorphic muscovite from a metarhyolite indicating that the arc sequence became part of a wide Tethyan Cretaceous accretionary complex by the latest Cretaceous. The youngest 40Ar/39Ar phengite age from the overlying subduction-accretion complexes is 92 Ma confirming southward younging of an accretionary-type orogenic belt. Hence, the arc sequence represents an intra-oceanic paleo-arc that formed above the sinking Tethyan slab and finally accreted to Laurasian active continental margin. Abrupt non-collisional termination of arc volcanism was possibly associated with southward migration of the arc volcanism similar to the Izu-Bonin-Mariana arc system. The intra-oceanic Kösdağ Arc is coeval with the obducted supra-subduction ophiolites in NW Turkey suggesting that it represents part of the presumed but missing incipient intra-oceanic arc associated with the generation of the regional supra-subduction ophiolites. Remnants of a Late Cretaceous intra-oceanic paleo-arc and supra-subduction ophiolites can be traced eastward within the Alp-Himalayan orogenic belt. This reveals that Late Cretaceous intra-oceanic subduction occurred as connected event above the sinking Tethyan slab. It resulted as arc accretion to Laurasian active margin and supra-subduction ophiolite obduction on Gondwana-derived terranes.
Copert4 Modeliyle Hesaplanan Karayolları Emisyonlarının Duyarlılığının İstanbul Hava Kalitesine Etkisinin Wrf/cmaq Model Sistemiyle Belirlenmesi

(Eurasia Institute of Earth Sciences, 2015-11-25) Kafadar, Müge ; Ünal, Alper ; 601121009 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Istanbul, the study area and the economic capital of Turkey, is the most populated city all around Europe with a population well over 14 million. The city has faced with environmental problems due to rapid urbanization and industrialization for a couple of decades. Air pollution is one of the most challenging problems for Istanbul where studies publicized that air pollution, particulate matter pollution in specific, has various serious effects on public health. Although air pollution is caused by numerous sources ranging from industrial to biogenic activities, emissions from motor vehicles have the most adverse effects on public health as they are released at the locations with certain levels where human activity is the highest. Traffic related emissions were calculated by using COPERT 4 (COmputer Programme to calculate Emissions from Road Transport) which is vehicle emission computation software and supported by European Environment Agency (EEA). Model input data were obtained from Turkish Ministry of Environment and Urbanization, and TUVTURK, then the data were processed by R that is a software environment for statistical computing and graphics. Besides fleet distribution process based on EURO levels, engine volumes, and fuel type was done first time for Istanbul, COPERT 4 was also run with this high resolution data. High-resolution emission inventory for other sectors, which is prepared by Dr. Ulaş Im, were employed. It can be summarized from the results of this analysis that road transport itself is solely responsible for 32 percent of CO emissions, as well as playing a main role in NMVOC emissions with the contribution of 43 percent to the total NMVOC emissions inventory, and NOx emissions with the contribution of 40 percent to total NOx emissions inventory. Furthermore, overall CO, NOx and PM2.5 contributions by road transport are found as 51%, 42%, and 11%, respectively. It is also realized that impact of road transport on inventory is higher than other sources. Vehicle emissions in inventory with this vitality increase the importance of determining the sensitivity and the uncertainty of calculations. To investigate the sensitivity of COPERT 4, three scenarios are determined based on temperature and speed parameters with numerous values that are strongly affecting the calculations. Then, base case emission values were compared with obtained emission values of these three scenarios. For the each scenario COPERT model was run and emissions of road transport was obtained. Then, calculated vehicle emissions used as input for air quality model. As a result of emissions for each scenario, a conclusion can be drawn that the major pollutant is NOx and minor pollutant is PM2.5 in general, where the emissions are higher in rural areas than urban areas and than the highways When a general analysis is done on scenarios regarding to pollutants, it can be realized that there is a decrease in emissions of all kinds of pollutants except CO as speed increases, and increase in emissions of all kinds of pollutants except CO as speed decreases. On the other hand, an obvious decrease in emissions of pollutants except NMVOC is realized in the case of temperature decrease. After evaluating the effect of change in model parameters on emission rates, air quality model was run to determine how would the effect of variation on emission rates embody in air quality. Model was first run for base case, then it is tried to determine the impact on air quality by running the model for each case separately. PM2.5 is analyzed since it has a significant effect on public health although it is not one of the pollutants that are caused by vehicle emissions. The day and time was examined when the gap is at maximum between the concentrations that are calculated for fundamental cases and the concentrations that are calculated within each model cell for all scenarios. It has been realized that there is 1.5 μg/m3 (~5%) decrease in PM2.5 concentration Istanbul-wide when results from CMAQ is analyzed within Scenario-I where the speed increased by 20%. 1.5 μg/m3 rate might be considered insignificant when it is compared with other average concentrations; however, it plays a key role on public health. In Scenario-II, it was realized that there is an average 2μg/m3 decrease in PM2.5 concentration depending on decrease in speed. This study can be advanced by obtaining higher resolution data that are employed for emission calculations of vehicles such as truck, bus, etc., by preparing more detailed emission inventory, and by employing the data suiting more accurate boundary conditions for air quality model.
Knidos Fay Zonu'nun Deprem Geçmişini Klor-36 Yüzey Yaş Tayini Yöntemiyle Modelleme

(Eurasia Institute of Earth Sciences, 2015-11-26) Şahin, Sefa ; Yıldırım, Cengiz ; 6011212010 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Knidos is an ancient city, which is located in the south of Gulf of Gökova in Western Anatolia. The Knidos Fault Zone is situated in ancient settlement ruins on the Datça Peninsula. The recent geological and archaeological evidences point out that this ancient site has been affected by at least two crucial momentous seismic events. In the light of this information, we have carried out cosmogenic 36Cl dating in order to obtain information about the seismic history of the Knidos Fault Zone. Using cosmic-ray surface exposure dating of a well-preserved limestone fault scarp facilitates us to attain information, which reveals a seismic history of faulting events and identifies timing and recurrence interval of past major earthquakes, and slip rates of the Knidos Fault Zone. There are two distinct faults located in the study area; those are the Demeter Fault and the Mezarlık Fault. I have chosen to aim at the Mezarlık Fault on account of that it has well-preserved fault scarp. The concentration of cosmogenic 36Cl isotopes measured in 128 limestone samples from a ~15m high bedrock fault scarp helps us to reveal the fault displacement history of the Knidos fault, in the Western Turkey. Although this method can cause breakthrough to the recent studies in earth science, there are plenty of limitations and uncertainties to deal with. The important factors are latitude and air pressure (elevation) scaling factors for a constant geomagnetic field, shielding resulting from the specific geometry of active normal faults, effects of the chemical composition of the colluvial wedge, effects of denudation of the scarp surface and snow cover effects on scarp shielding. Through the modelling of the cosmogenic 36Cl nuclides, it can be understood that Mezarlık Fault might be post-glacial as a result of previous studies implied in the similar fault scarps in the Mediterranean. As oppose to all of these limitations, it has been tried to understand impacts of these factors on the target fault by using recent numerical models. I have set out to obtain accurate conclusion through correlate and compare the result with synthetic profiles and previous studies as much as possible. The slip histories modelled via concentrations of 36Cl indicate that at least three or more events occurred on the Mezarlık fault within the past 20 kyr; over 10 meters of displacement took place between early Holocene and late Pleistocene. This study was conducted with the Decision of the Council of Ministers with No. 2013/5387 on the date 30.09.2013 and was done with the permission of Knidos Presidency of excavation in accordance with the scope of Knidos Excavation and Research carried out on behalf of Selçuk University and Ministry of Culture and Tourism.
Late Holocene High Resolution Multi-proxy Climate And Environmental Records From Lake Van, Eastern Turkey

(Eurasia Institute of Earth Sciences, 2015-11-26) Şimşek, Funda Barlas ; Çağatay, M. Namık ; 601062002 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri

Lake Van is the largest alkaline lake in the world characterized by varved sediments. It is located in eastern Anatolian plateau of Turkey. This study highlights the use of a multi-proxy approach toward understanding paleoenvironmental changes and sedimentation processes in Lake Van. We specifically focuse on climate records of the last 3500 years at centennial resolution. Compare the results with other studies in Anatolia, Near East and Europe. This study uses multi-proxy analyses of four interface sediment cores from different parts of the Lake. The multi-proxy data include ostracod counts, µ-XRF elemental, total organic (TOC) and inorganic carbon, C-N elemental and stable isotopes. For the age model of the core, we use radionuclide (210Pb and 137Cs) analysis and varve counting. Accelerator Mass Spectrometry (AMS) 14C dates from total organic carbon (TOC) indicates large differences with the corresponding varve ages, suggesting significant reservoir ages, which range from 1.2 to 3.8 ka BP. Double energetic window method by LSC which relies on the direct determination of 210Pb without waiting for the in growth of 210Po from 210Pb was used to construct the past environmental conditions of Lake Van in eastern Turkey. The results show that the sedimentation rate varies significantly among the four study sites, ranging between 0.3 and 0.7 mm.year-1.Varve counting of annually laminated sediments of Lake Van using digital X-ray radiographic images provided another means of dating the cores. Our study shows that varve counting method detects and counts fine-scale laminae, and produces robust varve ages that are comparable with independently determined 210Pb and 137Cs ages for the upper part of the core. All multi-proxy parameters including ostracods population, C/N ratio, stable isotope values, organic matter, Ti/Ca ratio showed 16 consistent periods varying between 100 and 350 years corresponding to alternation of cold/dry and warm/wet periods during the last 3500 years. The Lake Van climate records are conformable with the Lake Nar and the Sofular speleothem records as well as the European historical climate periods including Roman Warm Period (RWP), Dark Age Cold Period (DACP), Medieval Warm Period (MWP) and Little Ice Age (LIA), indicating teleconnections with the North Atlantic system. μ-XRF heavy metal profiles along the Lake Van cores show antropogenic inputs since 1960s. A significant increase occurred in metals such as Zn, Pb, Ni, and Co in the last 30-60 years in Lake Van cores. Especially increases in Zn and Pb in the upper parts of the cores indicate that important agricultural and industrial pollution began in the 1960s.
Atmospheric Circulation Types İn Marmara Region (nw Turkey) And Their İnfluence On Precipitation

(Eurasia Institute of Earth Sciences, 2015-12-04) Baltacı, Hakkı ; Kındap, Tayfun ; 601102003 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri

The Marmara Region comprises the northwestern end of Anatolia and the southeastern end of the Balkans: two peninsulas separated by Dardaneles and Bosphorus straits, and the Sea of Marmara. Located on two continents, Asia and Europe, this unique area is the most industrialized, agriculturally developed and populated geographical division in Turkey with a population density of up to 2500 people per km2 in Istanbul, averaging 300 people per km2 regionally. Parallel to its economic development, the region continues to draw migration from other regions in Turkey. This leads to an ever increasing demand for water, while threatening the existing water resources in the form of new and uncontrolled building activity over water reservoirs. Thus, amount and variability of precipitation play a key role in the management of limited water supply. Large-scale circulation patterns and synoptic patterns play significant role in determining the precipitation climate of the region. For the first time, in order to reveal the synoptic properties of the Marmara, circulation types, their long-term mean occurrence frequencies and relationships with precipitation are investigated. Automated Lamb Weather Types classification method is applied on NCEP/NCAR daily mean sea level pressure data to determine circulation types. Northeasterly (NE) and easterly (E) types are found to be the most frequent both on the annual basis and during winter (DJF, the wettest season in the region). Circulation types with the highest rainfall potential, namely the cyclonic (C) and northerly (N), are among the least frequent; therefore they are not the dominant "rainfall modes". Instead, NE and E have the greatest contribution to the regionally averaged rainfall amount, although they do not have the highest potential to create precipitation. This shows that Marmara Region receives a substantial amount of precipitation from northerly and easterly maritime trajectories, implying a profound influence of the Black Sea on the rainfall regime in this area. However, rainfall at the stations that are far away or less affected by the Black Sea (especially at the ones in the west) occurs during types with a southerly component (S, SW and SE). In addition to the relationship between CTs and precipitation in Marmara, the significant roles of the teleconnection patterns (TPs) on CTs and precipitation mechanism were also investigated. For this purpose, five main TPs, namely North Atlantic Oscillation (NAO), Arctic Oscillation (AO), East Atlantic (EA), East Atlantic-West Russia (EAWR) and Scandinavian (SCA) patterns index values were used. EA/WR is the most influential pattern in the occurrence of CTs during winter, exhibiting positive significant (at 99% level) correlations with NE and NW; and negative ones with SW and C. the strongest association of EA/WR is with NE and NW; and negative ones with SW and C. The second most influential teleconnection pattern on the CTs of Marmara Region during DJF is the AO, whose relationship with the occurrence of NE, SW and C is in the same fashion with EA/WR. Surprisingly, the NAO, whose wintertime impact on Turkey is the most studied and documented among all teleconnection patterns; has generally weak and insignificant influence on the occurrence of CTs in Marmara Region in DJF. In water management strategies, the amount of precipitation in particular basin has a great importance. Therefore, which CTs quantitatively cause precipitation occurrence and intensity in the sub-basins of the Marmara were investigated. By applying Ward's hierarchical cluster analysis, Marmara were divided into five coherent zones, namely Black Sea-Marmara, Black Sea, Marmara, Thrace and Aegean sub-regions. Precipitation occurrence suggested that wet CTs (i.e. N, NE, NW, and C) offer a high chance of precipitation in all sub-regions. For the eastern (western) part of the region, the high probability of rainfall occurrence is shown under the influence of E (SE, S, SW) atmospheric CTs. In terms of precipitation intensity, N and C CTs had the highest positive gradients in all sub-basins of the Marmara. In addition, although Marmara and Black Sea sub-regions have the highest daily rainfall potential during NE types, high daily rainfall totals are recorded in all sub-regions except Black Sea during NW types.
İstanbul'da Models-3/cmaq Model Sistemi Kullanarak Düşük Emisyon Bölgesi Çalışması

(Eurasia Institute of Earth Sciences, 2015-12-25) Ergül, Merve Gökgöz ; Ünal, Alper ; 601121003 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Istanbul is the most populated city of Turkey as well as one of the mega cities of the world. Due to growing population and economy, city has been experiencing the problems of air pollution. There are many studies about air pollution effects on human health in the literature. Road transport emissions are released in areas where people live intensively, therefore these emissions are important for public health. This thesis aims to identify and quantify the measures to be taken to prevent traffic-related air pollution by using WRF meteorology model and CMAQ chemistry and transport model. This study presents the first Low Emission Zone study in Istanbul by using modeling and highlights the requirements of Low Emission Zone establishment. Istanbul-specific inventory includes main anthropogenic sources on 2 km horizontal and hourly temporal resolution. Road transport emissions were obtained from COPERT emission model. Emission model results reveal that on-road traffic emissions are the main source for most of the pollutants such as CO, NMVOC and NOx, industrial combustion is responsible for high amount of SO2 emissions and solvent use and traffic are the main participants for NMVOC emissions. The spatial distribution of air pollutants has proved that the highest concentrations occur at the places where emission sources are located. But uncertainties may be occur due to the activity data, emission factors and temporal profiles used in this thesis. WRF model was run for a 11-day period, includes PM concentrations are mostly higher than EU limit value (50μg/m3), from November 2 to November 12, 2010. Model run results from the WRF simulation were compared with observations from Ataturk Airport and Goztepe air quality stations. According to statistical and time plot results WRF has captured surface temperature successfully. But this performance can be further improved by changing physical parameters of WRF. The results from the CMAQ model were compared with Aksaray air quality station based on PM10 concentrations. The statistical performance of model shows low correlation with the observations. Differences between model with measurement results can arise from many causes such as; uncertainty in the meteorological model and COPERT model, improper boundary conditions and temporal profiles and measurement errors. In order to limit traffic related air pollutants, methods and regions which have high density of population and work places were determined. Based on these criteria Historical Peninsula, Kadikoy and Maslak were selected as candidates. When transport sector emissions were reduced by 30% and given to DUMAN model, Historical Peninsula has demonstrated most significant response which is 10μg/m3 reduction in PM10 hourly concentration. Then, effect of each method on PM levels was examined by using literature studies and COPERT model. The most effective method was found as EURO 3 standard causes 85% reduction in PM10 emissions. In the case of only EURO 3, EURO 4, EUR0 5 and EURO 6 vehicles can enter the zone, hourly PM concentration differences between base situation and low emission case has reached up 35μg/m3. Overall, a low emission zone will be announced on the Historical Peninsula, will provide a significant improvement in regional air quality.
İzmir'deki Hava Kirliliğinin Atmosferik Modelleme Yoluyla Analizi

(Eurasia Institute of Earth Sciences, 2016-05-02) Özçomak, Duygu ; Ünal, Alper ; 601131001 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Besides being Turkey's third largest city with a population exceeding 4 million, İzmir is among the metropolitans that have major economic improvements. Economic growths of big cities inevitably bring some social and environmental issues as well. Among these, air pollution is the most serious and common one that both developed and developing countries are encountered. Air quality problem is affected from a lot of parameters especially in big cities. These include meteorology, topography, population, altitude, industrialization and social-economical developments. Exposure to pollution increases with the increasing human population living in developing urban areas. United Nations announced in 2000 that approximately half of the world population (48%) live in cities and every 3 years 2% growth is expected in the city populations. According to a research in 2013, twenty-three cities in the world have populations higher than 10 million. Air pollution is the existence of the foreign substances suspended in different phases of the atmosphere in varying amount, density and duration that damage human health, living organisms, and ecological balance. Therefore being exposed to air pollution became one of the inevitable results of urban life due to intense anthropogenic activities. Different researches are done on air pollution, which is a significant problem for both developed and developing countries. Especially air pollutants can threaten human health in various ways and levels. While there are high amounts of air pollutants, especially in urban areas, increase in mortality and morbidity rates has been discovered. Particularly lung diseases, neurobehavioral disorders and the effects of cardiovascular diseases are the main adverse effects of air pollution. Growing city population and industrialization level result in increasing energy demand. In densely populated areas, air pollution emission increases by rapid urbanization, transportation, energy production and industrial activities. Air quality management is one of the issues that need to be implemented urgently in the cities where strategical planning is limited or does not exist. Thus, developing emission inventories is one of the most important steps for air quality determination and improvement. These inventories are necessary tools for evaluating human and environmental risks, which are based on anthropogenic sources. Air quality control strategies are determined by air quality and emission standards defined by authorities in regional, national and global scales. Developing emission control strategies, determining applicability of control programs are required for creating reliable emission inventory. It is required to estimate the spatial and temporal density of emission sources in the best possible resolution for forming a healthy air quality control strategy and planning air pollution control reduction strategies. Having a reliable emission inventory is a primary requirement for qualified air quality management system. An emission inventory system supports pollution evaluation activities by data collection and scanning, storing, data organization. Also it creates databases for emission scenarios that will be prepared in the future. In this study, by improving existing emission inventory, activity data, which is more up-to-date and with reduced uncertainty, is compiled thus more reliable entries are provided for the air quality model. Via this model, which is run by the new inventory, temporal and spatial distribution of pollutants is investigated according to the sources. In the model, compiling of pollutants that are distributed according to the sources is set up based on sectoral distributions. Three types of source data is collected in the repository then are calculated depending on the calculation methods of source types. In the model, industry emissions are in SNAP-34 sector, traffic emissions exist in SNAP-7 sector. SNAP-7 also is divided into five based on source emissions. Regional sources named as domestic heating are calculated for SNAP-2 sector. While preparing emission inventory, for each sector required data is obtained from enterprises, calculations are done according to the related sector. Traffic emissions are calculated using COPERT 4 model, which is used in the transportation sector section of the İzmir's inventory. COPERT 4 traffic emission calculation model is commonly used for the calculation of vehicle emissions in several European countries. For industrial emissions, plants' direct emission measurements, which are provided by Izmir Provincial Directorate of Environment and Urban Planning, are calculated and used in the SNAP-34 sector of the study. For domestic heating emissions, which are provided by Izmır Provincial Directorate of Environment and Urban Planning by using the natural gas consumption and coal sales data, are calculated for SNAP-2 sector. In this study, WRF/CMAQ models included in EPA Models-3 system are used together. Meteorological and chemical transport models are run as two domains. Main domain includes whole Europe, North Africa and Eastern Asia, second domain covers whole Turkey and the resolutions are 30 km and 10 km respectively. WRF model is with 3 days spin-up timing is run for January 2010. For the result of the model, temperature and wind speed/direction data that is provided by İzmir Turkish State Meteorological Service is used and Gaziemir station performance analysis is done. When the temperature and station data are evaluated together, it is found that at temperatures in 2 m, for the trend and temperature values partially in line with the model estimations. For the evaluations of the wind speed and direction, at lower levels of wind speed, model estimates are compatible with station observations, although there are some deviations at certain days. There are some uncertainties in the model estimates regarding the wind direction and which is an expected situation. Following the evaluation of the changing model parameters' effects on emissions, air quality model is run to understand how these effects will be reflected into air quality. TNO/MACC-II inventory is used as a baseline scenario and run for 30 km and 10 km. Then CMAQ model is run once again for İzmir SNAP-2, SNAP-34 and SNAP-7 sectors with up-to-date emission data. For TNO inventory and new inventory that is created by new emission calculations, analyses are done by using different analysis methods and the affects of sectoral changes on the model results are investigated. For the emissions as TNO-OUR, total emission maps are created separately for each, the differences from each others are drawn as maps. In OUR emissions, for all pollutants changes are monitored according to the increases and decreases based on sectors. While PM10 emissions are decreased in SNAP-2, increased in SNAP-34 and SNAP-7, as a result overall PM10 emissions are increased. While CO is declined in SNAP-2 sector dramatically, it is increased sharply in SNAP-34 and SNAP-7 sectors. NOx is increased in the sectors except for SNAP-34. SO2 from pollutants is increased in all sectors. As a result of all these changes in emissions, different results are observed in the concentrations for each pollutant. In this study, distributions based on sectors takes into account for the spatial distribution of TNO inventory. Thus, the differences are considered based on the TNO spatial distribution. It is found that for all pollutant emissions and concentrations over İzmir, maximum changes are observed in city center. Through more detailed examinations, days and hours are determined where the maximum differences occur in concentrations and affects and results of these on emissions are investigated. Our findings indicate that the maximum impact of the CMAQ model's concentration results which are used by the newly developed emission inventory as an input, is observed in the İzmir city center where the most emission sources exist.
Wrf/cmaq Modelleme Sistemi İle Hava Kirliliğinden Kaynaklanan Avrupa'daki Tarımsal Zararın İncelenmesi

(Eurasia Institute of Earth Sciences, 2016-05-02) Öztaner, Yaşar Burak ; Ünal, Alper ; 601131005 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

The population of Europe, including non-EU countries located in continental Europe, is estimated to be around 740 million, which corresponds to 10% of the world's population (United Nations-UN, 2015). Wheat production in between 1996-2014 in Europe is 133.9 million tons (Mt). This corresponds to 21% of world's wheat production (FAO, 2015). In addition, because of Industrial Revolution in Europe an increasing trend in air pollution and pollutants that persists up to present day can be observed. This increase in air pollution is the cause of critical environmental impacts. Even though there are various studies in Europe about impacts of ozone on human health, not many studies exist to investigate ozone's impact on agriculture. Besides the negative impact on human health, exposure to high concentrations of ozone is a threat to food security and agricultural activities. Elevated O3 concentrations and changes in the concentrations affect plant life functions such as photosynthesis, transpiration, and gas exchanges. It has been found by many scientific studies that ground-level ozone exposure reduces photosynthesis of crops since it damages substomatals apoplast, cell membranes and walls. Decreased photosynthesis result in low growth rates in terms of volume or biomass. In Europe and United States of America (USA), various observational and experimental studies conducted on this subject. These studies resulted in different empirical ozone exposure equations for different parts of the world. Agricultural production losses can be calculated because of these equations. In Europe, AOT40 (cumulative summation of differences in high ozone concentrations over 40 ppb) is a widely used method which is a product of experimental studies conducted in Europe. However, in USA, W126 method (summation of weighted ozone concentrations in day light time by using sigmoidal distribution equation) is being widely used. Other than these two methods there are many other methods used around the world to calculate agricultural production loss due to ozone impacts. Some of these methods are daily summation of difference of threshold values (SUM-X method) or daily mean calculation (M-X method). There are several studies from different parts of the world that were conducted on the impacts of ozone on agricultural crops (i.e., wheat, soybean, rice, potato), their yield losses, and relative yield losses. In a study by USEPA, a 10% crop loss due to ozone was observed in agricultural production in USA. A similar study for the Europe found that the loss was around 5% in Europe. Tropospheric ozone as a regional and global threat to plants threatens our current and future food security. In literature, there are studies conducted on impacts of ozone on agricultural productions for different regions in the world. Even though these studies can show the local loss, they fail to perform well for regional impacts. For this reason, some scientific studies focused on quantifying the impact of ozone pollution on crops using regional or global atmospheric models. Low spatial resolution of global models affects the level of representation of results. Spatial resolution is better in regional studies compared to global ones, however, there are studies utilizing this higher resolution to calculate agricultural production losses. In a study, in India, conducted on impacts of ozone on wheat production loss using WRF/Chem regional chemical transportation model it was found that wheat production loss was 5 Mt for 2005. In a similar study, Eta-CMAQ regional chemical transport model was used to estimate the soybean loss in USA (2005), and found that amount of loss was in range of 1.7-14.2 %. Due to regional changes in ozone concentrations, working with a regional chemistry model yields better results for the calculation of agricultural production loss. In global models, there are many uncertainties due to low resolutions. In this study, WRF/CMAQ modeling system with three different ozone crop exposure indices (AOT40, W126, and M7) was used to estimate wheat production loss in Europe. Growing season was selected as May – July for wheat in Europe. European Environmental Agency (EEA) AirBase database ozone observations were used to calculate mean ozone values for growing season of years 2008 to 2012. The highest growing season average (45.6 ppb) was found in 2009. Averages for other years are as follows, 33.28 ppb for 2008, 29.29 ppb for 2010, 39.12 ppb for 2011, and 30.42 for 2012. This is the reason behind the selected study period growing season (May-July) of 2009. Country based total wheat production data for 2009 were obtained from Food and Agriculture Organizations (FAO). Spatial distribution of country based total wheat production data was performed by using gridded global wheat production map (for year 2000) from studies of Monfreda et al. (2008) and Ramankutty et al. (2008). For each grid cell countries contain a total value was found. These totals then divided by number of grid cells countries contain and grid cell ratios were calculated. These ratios were multiplied with total wheat production data of FAO 2009 and spatially distributed. This created map then remapped according to model area and resolution. In this study, modeling method is WRF / CMAQ modeling system with 30 km spatial resolution. As Meso-scale Atmosphere Circulation Model, WRF-ARW 3.6 (Weather Research and Forecast-Advanced Research WRF) was used with 35 horizontal levels, and with 191 cells in east-west and 159 cells in north-south direction. Also, 0.75 degree ECWMF Era-Interim Reanalysis data was used to prepare initial and boundary conditions of the model. For land-use, MODIS-30 20-class data was prepared. DUMANv2.0 emission model (developed by Istanbul Technical University, Eurasia Institute of Earth Science) was used for emission modeling. Inputs of emission model were anthropogenic, biogenic, and fire emissions. Anthropogenic emissions are created from TNO-2009 database by using DUMANv2.0 with CB05-AERO5 chemical mechanism. MEGAN v2.10 biogenic emission model was used for biogenic emissions. Fire emissions were calculated by data obtained from GFASv1.0 satellite dataset. CMAQv4.7.1 model with CB05-AERO5 chemical mechanism was used for chemical transportation modeling. WRF outputs were converted into M3MODEL structure by using MCIP (Meteorology-Chemistry Interface Processor). ICON (Initial Cond.) and BCON (Boundary Cond.) were used to create initial and boundary conditions. Inputs for these modules were obtained from ECMWF – MACC 3-hour model output with spatial resolution of 80-100 km. Open sky photolysis data were prepared with JPROC (Photolysis Rate Processor). Ozone variable was obtained from CMAQv4.7.1 model and applied to three ozone exposure indices. Gridded map of wheat production map of 2009 were multiplied with these values, thus calculated the wheat loss in each cell. Total economic loss was calculated by multiplication of calculated production loss and FAO 2009 country based wheat production price index. In order to calculate economic loss between countries, each country's 2009 GDP was normalized. The highest wheat loss was found in Russia (7.14 Mt - 11.6% and 17.3 Mt – 28%) by AOT40 and M7 methods while W126 method found the highest loss in Italy (1.54 Mt-24%). Following countries generally have higher wheat loss in every method, Turkey (6.8 Mt), France (3.47 Mt), Germany (2.45 Mt), and Egypt (5.54 Mt). According to the regional results the highest loss was found in South (8.3 Mt – 61%) and East (12.8 Mt – 37%) Europe, the lowest loss was found in Northern European countries (2.2%- 0.65Mt). Greatest losses were found in M7 method while W126 method has the lowest loss values. This provides a range (min-max) for ozone caused wheat loss in Europe. The highest economic loss was in Russia with 2.23 billion American Dollar (USD). Turkey ($2.24 bn), Italy ($1.64 bn), and Egypt ($ 1.59 bn) were other countries with high economic loss, right after Russia. Eastern Europe has the highest regional economic losses with ($1.6 bn) USD and Southern Europe ($2.8 bn). The lowest economic loss was in Northern Europe ($0.01 bn). Reason behind the high wheat loss values in Southern and Eastern Europe region is due to ozone precursor transport from Middle – Western European region via southerly – easterly meteorological systems. This causes higher ozone concentrations in Southern and Eastern Europe and affect wheat loss. Emission regulations should be more focused and applied in Middle – Western European countries.
İstanbul'daki Evsel Isınma Kaynaklı Emisyonların Cmaq Hava Kalitesi Modeli Kullanılarak İncelenmesi

(Eurasia Institute of Earth Sciences, 2016-07-07) Öksüz, Elvin ; Ünal, Alper ; 601121007 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Istanbul is the most populated city of Turkey as well as Europe. The population is over than 14 million. The city is economical center of the country. Labour and social opportunities makes the city attractive to live and this situation causes inevitable increasing on urbanization of the province. According to authorities, it is expected that the population will be over 16 million in 2030. Due to high population, house holding is also increasing. Distribution of buildings is expending over the city. Residential heating is the main requirement of the people in cold, winter season. By the high population and urbanization, residential heating emissions significantly affects air pollution over the city. Results of many epidemiological studies proves that air pollution causes negative impact on cardiovascular and respiratory system, serious diseases such as cancer and hearth attack. Especially for sensitive people such as elders, children, babies or pregnant the effects may be higher and vitally important. This study aims to examine residential heating impact over Istanbul city by atmospheric modelling. For this purpose WRF (Weather Research and Forecasting) meteorology model and CMAQ (Community Multiscale Air Quality) chemistry and transport model was applied. The first step was preparing emission inventory as input of the model. More complete and current emission inventory provides more trustable outputs. Residential heating emissions are generated with activity data and emission factor. The calculated emissions are also compared with TNO and EMEP emissions. Another purpose of this study was developing region specific emission factors of residential heating for Istanbul. The main fuels which are commonly used in the city are determined and combustion system is analysed. Residential heating is commonly supplied from natural gas and solid fuels such as coals and wood. The coals are classified as domestic and import coal. The fuels were burned in conventional stoves that is commonly used individual combustion system in Istanbul and pollutant concentrations are measured. The measurements for solid fuels were continuous and the concentration values of each pollutants are reported minutely. For natural gas, individual combustion system was combi and concentrations were measured instantaneously. Combustion systems, burning efficiency and calorific values of the fuels are essential for burning regime and pollutant concentrations. Moreover, fuel consumption per unit time is a critical parameter for emission factor calculation. By considering all these parameters and concentrations emission factors are calculated for each fuels and pollutants. The main pollutants of this source are SOx, NOx, CO, PM10. Moreover, uncertainties of region specific emission factors that are calculated with continuous measurements are evaluated for solid fuels. Statistical methods are used in order to quantify the factors. Both parametric and non-parametric bootstrapping techniques applied and many distribution fitting models and related diagnostics were applied in the study. The emissions via using calculated region specific emission factors and WRF meteorological model outputs were used as input of CMAQ. The study episode was three months that is from December 1, 2009 to February 30, 2010. As reference case CMAQ model is applied with TNO inventory and then the model is run for the same episode with new emission inventory that is updated with calculated residential emissions. The difference of concentrations between two model outputs provide to understand contribution of the revised residential emissions over the city. The days and hours that have maximum concentration differences are determined as giving the highest response to the new inventory.
Sahra Tozunun Doğu Akdeniz Hava Kalitesi Üzerindeki Etkilerinin Atmosfer Modeliyle Belirlenmesi

(Eurasia Institute of Earth Sciences, 2016-10-04) Kabataş, Burcu ; Ünal, Alper ; 601102002 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri

According to the World Health Organization (WHO), air pollution is a major environmental risk to health for urban population in both developed and developing countries and particulate matter (PM) affects more people than any other pollutant. Particles less than 10 micrometers are called PM10, and fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller are called PM2.5. Among sources of particulate matter, mineral dust is one of main contributors of natural aerosol emissions on a global basis contributing around 22% and Sahara is the main contributor to the global dust budget. Epidemiologic studies show that there is a clear link between the dust and adverse health problems such as respiratory diseases, cardiovascular diseases, pulmonary and systemic inflammation. Aside from its effects on human health, transported dust also affects ecosystem by transporting a variety of chemicals and microbial agents (such as bacteria, fungi, and viruses) from source area to other regions. Dust can have both physical and chemical impacts on plants. For instance, it may serve essential nutrients for plant growth such as iron, and phosphorus, yet microbial agents that can be carried thousands of miles in the atmosphere, might be pathogenic to the plants causing rust and other plant disorders. Mineral dust also has a direct role on the radiation budget and regional climate and has a semi-direct effect on cloud cover. Air pollution is one of the major environmental problems in the Mediterranean basin since the limit values of the pollutants are often exceeded. Saharan dust intrusions into the Mediterranean Basin affects 427 million people living in the 21 countries surrounding it. Considering its location, Turkey is downwind of Europe and on the crossroad of long-range dust transport and local emissions, meaning high amount of population living in Turkey are exposed to high PM concentration. The contribution of Saharan dust on PM concentration is still unclear in the Eastern Mediterranean, especially in Western Turkey, where significant industrial sources and metropolitan areas (i.e., Istanbul, Ankara and Izmir) are located. This study aims to quantify the contribution of Saharan dust on high levels of PM10 that was measured in April 2008 via ground observations, satellite data and atmospheric models. Ground observations that is used in this study were obtained from the Turkish Ministry of Environment and Urbanization for the year 2008. Data analysis of the ground observations showed April 2008 had significantly higher values compared to other warm season months with a monthly mean of ~87 μg/m3, where the annual mean PM10 concentration of 2008 was found to be ~82 μg/m3. It is known from the literature that the transition seasons are usually associated with dust transport from Sahara Desert in the Mediterranean Basin. One method to understand the complex nature of aerosol formation is via atmospheric models. In the real atmosphere, both meteorological factors (such as wind speed and direction, turbulence, radiation, clouds, and precipitation) and chemical processes (such as deposition, and transformations) play important roles on air quality and they are coupled. The interaction of meteorological factors on air quality and atmospheric transport of pollutants is well accepted and they can no longer be conducted separate from each other. Within this scope, we utilized the Real-time Air Quality Modeling System (RAQMS), which is an online global aerosol and chemistry assimilation and forecasting system that was run at 2x2 degrees horizontal resolution, to explore the possible effects of Saharan dust on high levels of PM10 measured in Turkey in April 2008. The RAQMS chemical scheme was developed at NASA Langley Research Center, and the aerosol module incorporates the Goddard Ozone Chemistry Aerosol Radiation and Transport (GOCART) mechanism. RAQMS simulates sulfate (SO4-2), dust, black carbon (BC), organic carbon (OC) and sea-salt aerosols that are known as the major tropospheric aerosol components. The model results showed that the high levels of PM10 observed for April 2008 are related to a Saharan dust outbreak. Due to its coarse resolution (2x2 degree) and inability to resolve local topographic variations, RAQMS was found to over predict the surface PM10 concentration over Turkey by up to a factor of 5. Continuation of the RAQMS research, the higher resolution (30km outer and 10 km nested domains) online-coupled regional Weather Research and Forecasting/Chemistry model (WRF-Chem), a version of the non-hydrostatic model WRF, was utilized. In order to include dust transport from North Africa through lateral boundary conditions (LBC), 6 hourly RAQMS 2x2 degree global analyses was used for 30km run. For background aerosol, GOCART simple aerosol module within the WRF-chem is used. For anthropogenic emissions, two different emission inventories are used, 1×1 degree spatial resolution RETRO (REanalysis of the TROpospheric)/EDGAR (Emission Database for Global Atmospheric Research) and 0.1×0.1 degree spatial resolution EDGAR HTAP (EDGAR: Emission Database for Global Atmospheric Research of the Joint Research Centre, JRC, in cooperation with the Task Force on Hemispheric Transport of Air Pollution (TF HTAP)), to investigate the spatial and temporal distribution of Saharan mineral dust transport over the Eastern Mediterranean (-10.0 W–60.0 E, 30.0 S–70.0 N) for the same time period. The WRF-Chem results were found to be significantly improved compared to the previous RAQMS study. WRF-Chem HTAP outer and nest domain were able to more accurately resolve local emissions that influence the ground observations than the WRF-Chem EDGAR run. The comparison between ground observations to the WRF-Chem HTAP model predictions indicated that the model was able to simulate dust transport patterns and the concentrations in a successful way. Followed by WRF-Chem study, we investigated the impacts of satellite data assimilation through assimilation of the Moderate Resolution Imaging Spectroradiometer (MODIS (collection 6)) total aerosol optical depth (AOD) retrieval products (at 550 nm wavelength) from Terra satellite within the National Centers for Environmental Prediction (NCEP) Gridpoint Statistical Interpolation (GSI) three-dimensional variational (3DVAR) data assimilation system by using the same configuration that was used for WRF-Chem experiment. The simple GOCART aerosol module that is implemented in WRF-Chem modeling system was used to assimilate 3-D mass concentration of 14 aerosol variables within the model including hydrophilic and hydrophobic components of atmospheric aerosols such as sea salt, dust, organic carbon (OC), black carbon (BC), and sulfate. Two nested domain (10km) experiments were designed to evaluate the impact of AOD DA on predicted PM10 concentrations over Turkey by using the same LBC obtained from 30km domain. Both 10km experiments used the same physical and chemistry options, but one experiment did not employ DA (10km_NoAssim) and the other employed 3DVAR DA (10km_Assim) that updated the 14 aerosol profiles of GOCART aerosol module. When we compared average model outputs with the observation means, we found that both 10km (10km_NoAssim and 10km_Assim) analyses show higher level of variability in the PM10 values compared to 30km_Assim run. Among the 10km runs though, 10km_NoAssim run showed higher level of variability than the 10km_Assim run. So, assimilation lowers the variability especially for the days when high dust event occurred. Daily comparison of surface PM10 measurements to model outputs showed that higher resolution domains (10km_Assim and 10km_NoAssim) overestimate daily surface mean PM10 values more than lower resolution domain (30km_Assim) does for the high dust event days. In order to explore differences in aerosol AOD assimilation between the high resolution domain (10km) and the 30km runs, we have interpolated 30km_Assim run to the 10km grid. Based on the PM10 differences averaged over the surface sites for 30km runs and 10km runs, April 1 and April 13, 2008 are chosen in order to further explore the consistency of the aerosol assimilation at 30 and 10km resolution. On April 1st low dust event day, over the central Anatolia, within the higher resolution domain, the predictions tend to increase due to the 30km_Assim domain influence through the LBC. This increase in higher resolution domain is corrected by employing assimilation by moving the predictions towards the observations. For the eastern part of the domain on April 1, the impacts of assimilation are similar for the 30 and 10km experiments indicating LBC impact is small. On April 13th, when dust is the dominant aerosol, 30km_Assim run shows higher PM10 concentrations than the 30km_Control run. The local emissions, as well as LBC from the 30km domain, add additional enhancements to 10km domain resulting an overestimation in 10km_NoAssim domain (due the large negative differences between 30km_Assim and 10km_NoAssim). Relatively small differences between the two 10km domains again shows that assimilation tends to move the 10km predictions closer to the surface observations during this high dust event. This demonstrates that, in our study, although the nested domains tend to over predict the PM10 concentrations comparing to the 30km domain, assimilation of satellite AOD retrievals moves the model forecasts towards the surface observations within the 10km resolution domains especially on high dust event days.
Sarıcakaya Sokulum Kayalarının (eskişehir, Kb Türkiye) Petrojenezi Ve Önemleri

(Eurasia Institute of Earth Sciences, 2016-11-25) Othman, Malik ; Topuz, Gültekin ; 601141010 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

This work deals with petrogenesis of the granitic rocks within the Sarıcakaya complex in western part of Sakarya zone. The Sarıcakaya complex is unconformably overlain by Middle Jurassic limestone and locally by Early Jurassic clastic rocks to the north, and is thrust over Late Triassic greenschist-facies metabasite and marbles (the Karakaya Complex). In addition, the Sarıcakaya complex is covered by the Tertiary continental sedimentary rocks to the southeast. In this study we employed deferent methods include geological mapping, sampling, petrographic description and bulk rock geochemical analysis. The metamorphic rocks are represented by amphibolite-facies micaschist, gneiss, amphibolite and metagranite. These rock assemblage is characteristic of a continental crust rather than a former oceanic accretionary complex. The metamorphic rocks are crosscut by (i) quartz diorite, (ii) biotite granite, (iii) mafic-ultramafic cumulate stocks, and (iv) voluminously minor felsic granites represented by two-mica granites and leucogranite with local muscovite and garnet. The contact metamorphic effects are only obvious around the gabbro-peridotite cumulate complexes. These maficultramafic cumulate rocks are formerly erroneously regarded as part of an ophiolite. The quartz diorite is metaluminous and medium to high-potassium calcalkaline I-type signature. It has probably formed as a consequence of substantial mantle involvement. Besides the cumulate rocks formed primarily by accumulation processes of a mantlederived basic magma. The hornblende-biotite granite is peraluminous and I-type granite with high-potassium alkaline nature. The leucogranite and two-mica granites are strongly peraluminous S-type granites, and represent partial melting products of continental crust. Available geochronological data on intrusive rocks from the literature suggest that the plutonism in the Sarıcakaya Complex occurred during Early to Late Carboniferous. Regional geological constrains are consistent with magmatic arc to post-collisional setting
insuyu Mağarasının Bakteriyel Ve Arkeal Biyoçeşitliliği

(Eurasia Institute of Earth Sciences, 2016-11-25) Tok, Ezgi ; Dalfes, Hasan Nüzhet ; 601131009 ; Climate and Marine Sciences ; İklim ve Deniz Bilimleri Anabilim Dalı

Caves are one of the unique habitats to see interaction between rock and microbes. In the aspect of microbiological researches, caves are unique environments in order to not only the limitations on exposing to exterior environmental conditions but also the natural isolation for disturbants such as other living creatures. In these harsh environments, Proteobacteria, Actinobacteria, Chlorobi/Bacteriodetes, Chloroflexi, Deltaproteobacteria, Acidobacteria, Nitrospirae, Actinobacteria and Betaproteobacteria are the most common and diverse group of bacteria because of their adaptation ability. In this study, we conducted cultivation-independent 16S rDNA surveys on the bacterial and archaeal community of Insuyu Cave, Burdur, TURKEY. The complexity of microbial communities has been presented in samples through PCR amplification of the 16S ribosomal RNA (16S rRNA) gene sequence, high resolution melting curve (HRM) and next generation sequence (NGS) based on 16S rRNA metagenomics from a variety of cave samples to identify bacterial and archaeal community profile of Insuyu Cave. A total of nine known bacterial class were found within the context of this research (Figure 3.4). The most prevalent class is alphaproteobacteria with 89,23% of the total bacteria found grouping into four order, with the most abundant ones: rhizobiales (88,85%) and sphingomonadales (0,21%). The followings, ordered by abundancy, are actinobacteria (3,94%), bacilli (2,92%), gammaproteobacteria (1,69%) and betaproteobacteria (0,74%). Also, a total of fourteen genera from ten order were identified in this study (Figure 3.5). The most dominant is methylobacterium with 88,83%, from the class of rhizobiales (88,85%). The followings are propionibacterium (3,58%), dolosigranulum (1,69%), streptococcus (1,10%) and pseudomonas (1,13%). On the other hand, no Archaeal species has been detected at the result of NGS analysis while some archaeal nucleic acid had been marked as a result of PCR analysis. The reasons of this situation has been investigated in the section of discussion.
Türkiye İçin Gözleme Ve Modele Dayalı Yağış Veri Kümelerinin Kapsamlı Bir Değerlendirmesi

(Avrasya Yerbilimleri Enstitüsü, 2017-05-04) Girgin, Gizem ; Şen, Ömer Lütfi ; 601151002 ; İklim ve Deniz Bilimleri Anabilim Dalı ; Climate and Marine Sciences

Yağış, farklı birçok sektör ve disiplindeki araştırmalar ve çalışmalarda sıklıkla ihtiyaç duyulan iklim parametrelerinden biridir. Ancak mekansal değişkenliğinin yüksek olması ve süreksizliği nedeni ile tahmin edilmesi oldukça güçtür. Bu yüzden, Dünya'da farklı yöntemler ile oluşturulmuş birçok veri kümeleri bulunmakta ve oluşturulmaya ve geliştirilmeye devam edilmektedir. Türkiye'nin sınırlarını kapsayan gridlenmiş çeşitli küresel ve bölgesel yağış veri kümeleri bulunmaktadır, fakat bu veri kümeleri arasında kullanılan istasyon sayısı, çözünürlük ve kullanılan interpolasyon teknikleri vb. nedenlerden dolayı farklılıklar vardır. Bu çalışmanın öncelikli amacı; bu veri kümelerinin karmaşık bir topoğrafyaya sahip olan Türkiye'nin yağışının zamansal ve mekansal dağılımını ne kadar iyi temsil ettiği hakkında fikir sahibi olmaktır. Bu gridlenmiş veri kümeleri, istasyon ve uydu ölçümlerinden elde edilmiş verileri, yeniden-analiz verilerini ve iklim modelleri ile oluşturulmuş verileri içermektedir. Çalışmada veri kümeleri mekansal, mevsimsel ve istatiksel olarak karşılaştırılmıştır. Referans veri kümeleri olarak gözlem veri kümelerinin ortalaması kullanılmıştır. Veri kümelerinin zamansal dağılımı göz önünde bulundurularak 1961-1990 ve 1998-2007 dönemi olmak üzere iki farklı dönem analiz edilmiştir. Ayrıca çalışmada Türkiye iklim özelliklerine göre Karadeniz, Akdeniz ve Doğu Anadolu olmak üzere üç bölgeye ayrılmış ve istatiksel analiz sırasında bu bölgeler için de veri kümeleri incelenmiştir. Türkiye haritaları ile her bir veri kümesinin Türkiye için yağış dağılımı incelenmiştir. Dönem ortalamaları tablosu ile veri kümeleri büyüklük açısından karşılaştırılmıştır. Türkiye fark haritaları kullanılarak refereans veri kümeleri ile aralarındaki farklar gözlenmiştir. Mevsimsel analizler de ise, her iki dönem için mevsimlik ortalamalar karşılaştırılmış ve aylık dağılım grafikleri ile aralarındaki farklara bakılmıştır. İstatiksel analiz için Taylor Diyagramı kullanılmıştır ve veri kümelerinin referans veri kümesi ile olan uyumu incelenmiştir. Elde edilen sonuçlara göre sıklıkla kullanılan veri kümeleri arasında dikkate değer farklılıklar gözlenmiştir. Türkiye için gözlem veri kümeleri dağılım ve büyüklük açısından model ve yeniden-analiz veri kümelerine göre daha iyi sonuçlar vermiştir. Model, yeniden-analiz ve uydu veri kümeleri gözlem veri kümelerine göre büyüklük olarak daha yüksek değerler göstermişlerdir. Özellikle yeterli sıklıkta istasyon ağı bulunmayan dağlık bölgelerde model veri kümeleri gözlem veri kümeleri arasındaki fark daha fazladır. Buna en iyi örnek; Doğu Karadeniz bölgesidir. Mevsimsel olarak incelendiğinde veri kümeleri arasındaki farkların kış ve bahar aylarında artmaktadır. Genel olarak bakıldığında, referans veri kümesi olarak kullanılan ENSEMBLE veri kümesine en yakın tahminde bulunan veri seti çalışmada TR_STA_GRIDDED olarak isimlendirilen Türkiye istasyon veri kümesidir.
Kalkolitik Ve Tunç Çağlarında Göller Bölgesindeki İklimsel Değişiklikler Ve Bu Değişikliklerin Bölgedeki Arkeolojik Yerleşim Sistemlerine Etkisi

(Avrasya Yerbilimleri Enstitüsü, 2017-05-05) Tekin, Arman ; Arıkan, Bülent ; 601131008 ; İklim ve Deniz Bilimleri Anabilim Dalı ; Climate and Marine Sciences

Bu çalışmanın amacı, Kalkolitik ve Tunç çağlarında (~G.Ö.8000-3000/~M.Ö. 6000-1000) Göller Bölgesi'nde meydana gelen iklimsel değişiklikleri bir paleoiklim modeli yardımıyla modelleyerek önemli iklimsel parametrelerin (yıllık ortalama yağış ve sıcaklık gibi) gösterdiği değişimlerin derece ve önemini kantitatif yöntemlerle çalışmaktır. Bu değişimlerin bölgede yapılan arkeolojik yayınlardan oluşturulan arkeolojik yerleşim sistemlerine etkisini araştırmaktır. Göller Bölgesi coğrafik ve kültürel açıdan bakıldığında Burdur, Isparta ve Antalya illeri ile temsil edilmektedir. Çalışma kapsamına Ege, Akdeniz ve İç Anadolu bölgeleri arasındaki ilişkileri anlamak adına Afyon ve Konya illeri de dâhil edilmiştir. Bu illerinden elde ettiğimiz iklimsel kayıtlar ve çalışma dönemini temsil eden 500'ü aşkın arkeolojik yerleşme kullanılmıştır. Bu çalışma kapsamında istatistiksel verilerin incelenmesi için R Studio kullanılmış, çalışılan bölgenin mekânsal verilerinin bilgisayar ortamında toplanması, coğrafi bilgi sistemine girilmesi, mekânsal analizlerin yapılması, görüntülenmesi ve uygun formatta çıktı alınabilmesi için ise açık kaynak kodlu GRASS CBS (Coğrafi Bilgi Sistemleri) kullanılmıştır. Yapılacak olan tüm analizlerin ve buna bağlı elde edilecek olan tüm verilerin, geçmişteki iklimsel değişiklilerin arkeolojik yerleşim sistemlerini ne derece etkilediğini anlamak için ise Makrofiziksel İklim Modeli (MİM) kullanılmıştır. Çalışmadan elde ettiğimiz ilk verilere göre, Kalkolitik Çağ'dan Erken Tunç Çağı sonuna kadar (~G.Ö. 8000-4000/~M.Ö. 6000-2000) arkeolojik yerleşmelerin sayısında artış görülmüştür. Bu süre içerisinde ise yaşayan Göller Bölgesi insanlarının yeryüzü şekilleri içerisinde düzlük alanlarda, suya yakın geçiş noktalarında (kanal) ve dağın bayır kısımlarında yaşamayı, zirve ve vadilere oranla daha fazla tercih etmişlerdir. Yağış ve sıcak verilerine bakıldığında ise, Geç Kalkolitik Çağ'dan Geç Tunç Çağı sonuna kadar (G.Ö. 5600-3000/M.Ö. 3600-1000) olan zaman diliminde yağışta ve sıcaklıkta azalmaların görüldüğü ve buna ek olarak her 2000 yıllık süreçte Göller Bölgesinde yerel ve bölgesel değişimlerin olduğu gözlenmiştir. Yine yağış ve sıcaklık verileri göz önünde bulundurulduğunda, 4.2 ka iklim olayının Göller Bölgesi için bölgesel bir kuraklığı işaret etmediği görülmektedir. Orta Holosen sürecindeki iklimsel değişikliklerin, bu dönemde yaşamış toplulukların sosyal, ekonomik ve siyasi sistemlerin değişmesinde payı olabileceği düşünülse bile, bu değişimin sadece yerel ölçekte gerçekleştiği ve küresel bir etkisi olamayacağını söylemek doğru olacaktır.
Van Gölü'nün sedimentolojik-stratigrafik evrimi ve göl seviyesi değişimleri

(Avrasya Yer Bilimleri Enstitüsü, 2017-12-19) Damcı, Emre ; Çağatay, Memet Namık ; 601062008 ; İklim ve Deniz Bilimleri Anabilim Dalı ; Climate and Marine Sciences

Van Gölü konumu gereği iklime duyarlı bir bölgede, Doğu Anadolu yüksek platosu, üzerinde yer almaktadır. Arap plakasının Avrasya levhasıyla çarpışması sonucunda platonun yükselmesi yaklaşık 12 Myıl'da başlamıştır. Göl; batıda ve kuzeyde Kuvaterner volkanları, güneyde Paleozoyik Bitlis Masifi ile çevrilidir. Doğuda ise yığışım karmaşığına ait birimler ve Plio-Kuvaterner çökelleri yer almaktadır. Ayrıca bölge, Kuzey Atlantik, Sibirya yüksek basınç ve orta enlem subtropikal yüksek basınç sistemlerinin kesiştiği bir noktada, Doğu Anadolu ve Akdeniz arasındaki iklime hassas bir bölgede yer almaktadır. Bulunduğu bu konum itibari ile iklim çalışmaları açısından önem arz etmesinin yanında gölün varvlı çökelleri ile paleoiklim, tektonik ve volkanoloji çalışamaları bakımından da bulunduğu bölgenin karmaşık yapısına ışık tutması açısından ilgi odağı olmuştur. Van Gölü Havzası, doğu-batı uzanımlı Muş depresyonunda Arap, Avrasya levhalarının çarpışması ile şekillenmiştir. Paleotektonik olarak sınıflandırılan bu birimlerin üzerine Miyosen-Kuvaterner yaşlı Neotektonik döneme ait birimler gelmektedir. Alt Miyosen-Pliyosen'de denizin çekilmesi ile bölge aşınma etkisinde kalmış ve bu dönemde genç volkanizma ürünleri bölge yüzeyini kaplamaya başlamıştır. Temelde yer alan birimlerin üzerine, göl içerisinde uyumsuzlukla gelen Pleyistosen-Kuvaterner çökelleri gelmektedir. Bu birimler içerisinde ise, Kuvaterner'de aktif olan Nemrut, Süphan ve İncekaya volkanlarına ait tefra birimleri yer almaktadır. Gölün oluşum yaşı volkanizma ve jeolojik çalışmaların yanı sıra ICDP PALEOVAN projesi kapsamında yapılan çalışmalar ile GÖ 600 kyıl olduğu ve Nemrut Volkanının faaliyete geçmesi ile volkanik bir set gölü olarak oluştuğu anlaşılmaktadır. Yapılan çalışmalarda, KB-GD sıkışma rejimi altında doğrultu atımlı fayların da etkisiyle şekillenen, başlangıçta Muş Havzası ile bağlantısı olan göl, ilk önce tatlı su gölü olarak oluşmuş, daha sonra Nemrut Volkanı'nın faaliyetleri sonucu gölün dışarı akışı kesilerek, volkanizma, kayaç ayrışması ve buharlaşmanın etkisi ile bugünkü kapalı, acı-alkali göl halini almıştır. Van Gölü, 607 km3 hacim, 3570 km2'lik alan ve 450 metrelere varan derinliği ile Türkiye'nin en büyük gölüdür. Van Gölü, 450 m derinliğindeki Tatvan Havzası, 260 m derinliğinde Kuzey Havzası (NB), batıda kuzeydoğudaki kuzey-kuzeydoğu yönünde yönelim gösteren Ahlat (AR) ve Kuzey Sırtı, kuzeydeki Erciş Körfezi ve Erek Fanı, doğuda Doğu Şelfi ve Doğu Fanı gibi birkaç morfolojik bölgeden oluşmaktadır. Bu tez çalışmasında, gölün sedimanter, tektonik ve paleoiklimsel evrimini anlamak için, göl içerisinde piston karot ve karotlu sondaj çalışmaları yanında sismik yansıma ve batimetri verileri toplanmış ve yorumlanmıştır. Tez çalışması kapsamında değerlendirilen 4-5 m uzunluğundaki piston karotlar Van İlinin batısında Doğu şelfi olarak adlandırılan bölgeden alınmıştır. Sondaj karotları ise ICDP PALEOVAN projesi kapsamında gölün kuzeybatısında yer alan NB olarak adlandırılan bölgede 245m su derinliğinden ve AR olarak adlandırılan bölgede 375m su derinliğinden alınmıştır. Göl tabanı çökellerinden alınan NB ve AR karotların uzunluğu göl tabanından itibaren sırası ile 145 m ve 220 m'dir. Alınan bu çökel karotlarda, çok sensörlü karot tarayıcı (Multi Sensor Core Logger – MSCL) ile yapılan ölçümlerden, karot boyunca p-dalgası hızı, manyetik geçirgenlik, gama yoğunluk ve özdirenç gibi fiziksel özellikleri hesaplanmıştır. P-dalga hızları ve gama yoğunlukları kullanılarak üretilen yapay sismogramlar yardımıyla çökel karotları ile sismik kesitler deneştirilmiş ve gölün sedimentolojik ve tektonik evrimi ile ilişkilendirilmeye çalışılmıştır. μ-X-Ray Florescene (XRF) tarayıcı ile çökel karotların derinlik boyunca element analizleri yapılarak Ca/Fe, Ca/Ti gibi iklimden etkilenen element oranları ile göl su seviyesi ve iklim değişimleri ile ilişkisi çalışılmıştır. Bunun yanı sıra K, Zr, Na, gibi elementlerin gama yoğunluk ve manyetik geçirgenlik verilerinin birlikte değerlendirilmesi ile çökel istifteki volkanizma ürünü çökelimlerin tespitine yönelik çalışmalar yapılmıştır. XRF tarayıcıdan elde edilen radyografi görüntülerinden tez çalışması kapsamında MATLAB yazılımı kullanılarak geliştirilen algoritma ile mevsimsel değişimlere bağlı olarak çökelen laminaların sayımı yapılarak, yıllık çökelimi oluşturan varvların kalınlığı hesaplanmış ve karot boyunca, yine karot çökelleri içerisinden alınan bitki parçası örneklerinden yaptırılan radyokarbon ve tefra örneklerinden alınan 40Ar/39Ar tarihlendirme analizleri ile, karot istiflerininin kronolojisi oluşturulmuştur. Bu kronoloji Grönland buzul karotları (NGRIP, intGRIP) ve denizel izotop dönemleri (MIS) ile desteklenmiştir. Kronolojiye bağlı jeokimyasal-sedimentolojik verilerin spektral sinyal analizi yapılarak, buradan iklime ait döngüsellikler belirlenmiş ve geçmiş iklim modellemesi yapılmıştır. Spektral analizin yanı sıra değişik periyotlarda çökel kalınlıkları grafiklenerek çökelim hızındaki farklılıklardan kurak/soğuk ve nemli/ılıman iklim dönemlerinin belirlenmesine çalışılmıştır. Oluşturulan bu iklim modelinin, tez çalışması kapsamında değerlendirilen diğer verilerden elde edilen bulgular ile karşılaştırılması yapılarak, göl su seviyesi değişimleri ve bu değişimin üzerinde iklimin etkisi tartışılmıştır. Verilerin değerlendirilmesi sonucu oluşturulan iklim modeli ve göl su seviyesi değişimleri, Van Gölü'ndeki ve literatürdeki diğer çalışmaların sonuçları ile karşılaştırılmıştır. Toplanan sismik yansıma ve batimetri verilerinden gölün batimetri haritası oluşturulmuş. Sismik yansıma verilerinin yorumlanması ile göl çökellerinin GÖ 600 kyıl'dan bu yana Tatvan Havzası'nda ve yaklaşık GÖ 90 kyıl'dan bu yana Kuzey Havzası'nda süreklilik gösterdiği sonucuna ulaşılmıştır. Çok kanallı sismik yansıma kesitleri ile oluşturulan yaş modeli korelasyonu ile günümüz göl su seviyesinin yaklaşık 200 m altında D1 deltasının GÖ 20-17 kyıl, 105m altında D1a deltasının G.Ö 65-60 kyıl, 150m altında D2 deltasının GÖ 115-106 kyıl, 225 m altında D3 deltasının GÖ 166-142 kyıl, 300 m altında D4 deltasının GÖ 195-169 kyıl, 375m altında D5 deltasının GÖ 270-234 kyıl ve 450m altında D6 deltasının 400-350 kyıl aralığında çökeldikleri belirlenmiştir. Yüksek çözünürlükte sismiklerde ise, günümüz göl su seviyesinin 60 m altında GÖ 4-3 kyıl göl seviyesine ait klinoform ile, 30 m, 20 m ve 15 m altında tarihlendirilemeyen; ancak GÖ 3 kyıl'dan sonrasında, olasılıkla Yunan Karanlık veya Demir Çağı Soğuk Dönemi, Avrupa Karanlık Çağı ve Küçük Buzul Çağı dönemine ait olan düşük göl seviyesine ait delta ve kıyı düzlükleri (taraçalar) tanımlanmıştır. Van Gölü içerisinde sualtı kanal sistemleri, Doğu Şelfi'nde ve Erciş Boğazı'nda oldukça gelişmiş bir yapı göstermektedir. Kara üzerinde yer alan akarsu drenaj sistemi ile bağlantılı olarak göl içerisinde 100 m'den daha fazla su derinliklerine kadar uzanırlar. Genel olarak kanallar 50 m kadar derin ve 500 m genişliğindedir. Şelf üzerinde ve eğimli alanlarındaki sualtı kanal sistemleri, Van Gölü su seviyesinin günümüze kıyasla, G.Ö 15 kyıl'da 200m ve Younger Dryas (YD) döneminde 70m gibi göl su seviyesinin daha düşük olduğu dönemlerde gelişmiştir. Varv kalınlıklarından yıllık çökelim hızları hesaplanmıştır. Kuzey Havzada göl çökelleri türbidit ve tefra ardalanmalı şekilde çökelmiştir. Burada tefra ve kütle akması birimleri hesaba katılmadan elde edilen Holosen ve en geç Pleyistosen dönemindeki çökelme hızları; 5,8-12,65 kyıl arasında 0,43 mm/yıl ile en düşük, 12,65-13,89 kyıl arasında 3,72 mm/yıl ile en yüksek çökelme hızlarına sahip dönemlerdir. Holosen'deki ortalama çökelim hızı ise 1,54 mm/yıl'dır. Kuzey Havzası'ndaki çökelim hızı, Tatvan Havzasındaki ve Doğu Deltasındaki çökelimden kabaca iki kat daha hızlıdır. Gerek AR sondajından gerekse kısa karotlardan elde edilen çökelim hızları yaklaşık 0,4-0,7 mm/yıl arasındadır. Varv kalınlıklarının spektral dekompozisyonu ile iklimsel periyodların belirlenmesi ve bu periyodlar ile oluşturulan geçmiş iklim modellerinin literatürde yer alan Bond, Heinrich (H), Dansgaard-Oeschger (DO), güneş aktivitesi minimumları ve tarihsel olaylar ile uyumu Van Gölü'ndeki çökelimin iklimsel dinamikler ile uyumlu olduğunu göstermektedir. Aynı zamanda bu uyum, birim zamanda çökel istifin kalınlığının bilinmesi ile geçmiş iklim modelinin oluşturulabileceğini göstermiştir. İklim modelinden elde edilen sonuçlara göre; GÖ 82-81 kyıl, GÖ 71-69 kyıl, GÖ 62-60 kyıl, GÖ 58-GÖ 55 kyıl, GÖ 38-35kyıl, GÖ 18-16 kyıl, GÖ 5-4,8 kyıl, 4,4-4,2 kyıl, GÖ 2,7-2,6 kyıl, GÖ 1,6-1,2 kyıl (MS 450-800), 0,7-0,45 kyıl (MS 1300-1550), MS 1790-1840 ve MS 1880-1950 göreceli en soğuk dönemler; GÖ 87-82 kyıl, GÖ 65-62 kyıl, GÖ 47-43 kyıl, GÖ 32-30 kyıl, GÖ 22-21 kyıl, GÖ 8-5 kyıl, GÖ 4,8-4,4 kyıl, GÖ 3,2-3,15 kyıl, GÖ 2,6-2,5 kyıl, GÖ 1,8-1,65 kyıl (MS 200-450), GÖ 1,2-0,95 kyıl (MS 800-1050), MS 1550-1790, MS 1840-1880 ve MS 1950'den günümüze göreceli sıcak dönemler olarak iklim modelinden elde edilmiştir. Tektonik rejimin sürekliliği bölgede sıkışan havzaların daralarak D-B ve KB-GD doğrultulu kıvrımlanmasına ve volkanizma ile beraber havzaların bölünmesine sebep olmuştur. Van Gölü içerisinde yer alan Kuzey Sınır Fayı (KSF) boyunca oluşan AR ve Kuzey Sırt (KS), gölün kuzeyinde yer alan havza ile Tatvan Havzası'nı birbirinden ayırmaktadır. Muş Havzası ile Van Gölü Havzası'nı ise, Üst Miyosen'de Avrasya Levhasının altına dalan okyanus kabuğunun kopması ile açılan pencereden giren magma sonucu Kuvaterner başlarında geliştiği öne sürülen Nemrut Volkanı ayırmaktadır. Havzayı güneyden sınırlayan Güney Sınır Fayı (GSF) boyunca benzer özellikteki volkanik kraterlerin yer alması, magmanın yüzeye ulaşmasında bu fayın etkisinin olduğunu göstermektedir. KB-GD yönlü sıkışma rejimi altında, genel olarak KB-GD yönlü normal fay sistemi gelişmiştir. Bu fay sistemi boyunca karbonat kayaç birimlerinin yer aldığı Adilcevaz ve Tatvan açıklarında bikarbonatça zengin yer altı suyu ile beslenerek, sismik kesit ve batimetri verilerinde de açık bir şekilde gözlemlenen, boyları 30 m'ye varan mikrobiyolitler oluşmuştur. Gölün güney şelfinde, sismik ve batimetri verilerinden KB-GD doğrultulu düşey bileşene sahip sol yanal atımlı bir fay belirlenmiştir. Bu fay büyük olasılıkla 9 Kasım 2011'de meydana gelen Mw= 5,7 büyüklüğündeki Edremit depreminin kırığıdır. Ayrıca Erciş Boğazı'ndan güneye yönelen kanal sistemlerinin de fay kontrollü geliştiği anlaşılmıştır. Erciş Boğazı'nda yer alan sismik kesitte gözlenen fayın düşey atım hızı 0,43 mm/yıl olarak hesaplanmıştır.

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