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Öğe Biga Yarımadasında Jeodeğerler ve Jeoturizm Potansiyeli(TMMOB Jeoloji Muhendisleri Odasi, 2018) Çalık, Ayten; Kapan, Sevinç; Erenoğlu, Ramazan Cüneyt; Erenoğlu, Oya; Yaşar, Cumali; Ulugergerli, Emin UğurIt is summarized what needs to be done and to be able to utilise three structurally different geological formations within the Canakkale province as geo-parks or geovalue that can attract geologically important and interestingtosocieties. As examples, hot water springs of Tuzla geothermalarea, ancient granite columns of Kestanbolu-Yahya Cavusvillage and opal pit of Yenice village are taken as examples. It is also emphasized that besides the areas highlighted, all other possible areas have their own specific conditions and that ignoring these conditions may cause permanent damages to the area. Earth science museum are also important institutions that will contribute to the discovery and introduction of these fields. As a way of preserving areas that are both scientific and tourist attraction, we have also listed our views on the importance of opening up and exploring to public and the negativity of this activity. According to the first results, while the Tuzla Geothermal field could be used with a few simple arrangements but Kestanbol and Yahya Cavus villages could not be used for the purpose of geotourism with its current state of the fields.Öğe Improving food security as disaster relief using intermediate moisture foods and active packaging technologies(Elsevier B.V., 2024) Aydın, Alper; Yüceer, Muhammed; Ulugergerli, Emin Uğur; Caner, CengizThis study aims to present alternative solutions for food aid that meet the needs of disaster victims after significant disasters. Food support in post-disasters period is a vital humanitarian service that enables disaster victims to survive and maintain their health. Providing that, the food must have a long shelf life and be nutritious and safe. Intermediate moisture foods (IMF) are shelf-stable products and have a high potential for use in disasters. Recent developments in active packaging (AP) technologies helps to enhance the quality and extend the storage stability of food, including the IMF. This study shows that AP technologies with antimicrobial agents, oxygen and moisture absorbers can improve the storage stability of food and reduce the risk of microbial contamination. Furthermore, using these technologies in food packaging can provide sustainable alternative to conventional packaging and increase the stability of food in potential future disasters.Öğe The Atlas of Morocco: A Plume-Assisted Orogeny(John Wiley and Sons Inc, 2023) Lanari, R.; Faccenna, C.; Natali, C.; Fellin, M. G.; Becker, T. W.; Şengül-Uluocak, EbruWe explore the connections between crustal shortening, volcanism, and mantle dynamics in the Atlas of Morocco. In response to compressional forces and strain localization, this intraplate orogen has evolved far from convergent plate margins. Convective effects, such as lithospheric weakening and plume-related volcanism, contributed in important ways to the building of high topography. We seek to better understand how crustal and mantle processes interacted during the Atlas' orogeny by combining multiple strands of observations, including new and published data. Constraints on crustal and thermal evolution are combined with new analyses of topographic evolution, petrological, and geochemical data from the Anti-Atlas volcanic fields, and a simple numerical model of the interactions among crustal deformation, a mantle plume, and volcanism. Our findings substantiate that: (a) crustal deformation and exhumation accelerated during the middle/late Miocene, contemporaneous with the onset of volcanism; (b) volcanism has an anorogenic signature with a deep source; (c) a dynamic mantle upwelling supports the high topography. We propose that a mantle plume and the related volcanism weakened the lithosphere beneath the Atlas and that this favored the localization of crustal shortening along pre-existing structures during plate convergence. This convective-tectonic sequence may represent a general mechanism for the modification of continental plates throughout the thermo-chemical evolution of the supercontinental cycle.Öğe The neglected Istanbul earthquakes in the North Anatolian Shear Zone: tectonic implications and broad-band ground motion simulations for a future moderate event(Oxford University Press, 2023) Tan, Onur; Karagöz, Özlem; Ergintav, Semih; Duran, KemalIstanbul (Marmara Region, NW Turkey) is one of the megacities in the world and suffered from destructive earthquakes on the North Anatolian Fault, a member of the North Anatolian Shear Zone, throughout history. The 1999 Kocaeli and Duzce earthquakes emphasize the earthquake potential of the fault, crossing the Sea of Marmara, and the importance of seismic hazards in the region. The studies in the last 20 yr have concentrated on the main fault and its future destructive earthquake potential. In this study, unlike the previous ones, we focus on the two main topics about the earthquakes not interested previously in Istanbul: (1) Investigating recent earthquake activity masked by the blasts in the metropolitan area and its tectonic implications, (2) revealing their effects in Istanbul utilizing numerical ground motion simulations for a future moderate event (M-w 5). First, the 386 earthquakes from 2006 to 2016 are relocated with the double-difference method using the dense seismic network operated in the same period. The source mechanisms of the events (M-L >= 3), including the most recent 2021 Kartal-Istanbul earthquake (M-L 4.1), are determined. In addition to the analysis of the recent seismic activity, the location of the two moderate and pre-instrumental-period Istanbul earthquakes, which occurred in 1923 (M-w 5.5) and 1929 (M-w 5.1), are revised. Using the relocated epicentres outside of the principal deformation zone and the fault plane solutions, the roles of the earthquakes in the stress regime of the Marmara region are explained. The epicentres on the Cenozoic or Palaeozoic formation in the Istanbul-Zonguldak Zone are interpreted as the re-activation of the palaeo-structures under the recent tectonic stresses, and their fault plane solutions agree with the synthetic/antithetic shears of a transtensional regime corresponding to the right lateral strike-slip system with mainly N-S extension in the Marmara Region. In the second part, we investigate the effects of moderate scenario events (M-w 5) considering the current earthquake epicentres in the Istanbul metropolitan area, using characterized earthquake source model and 1-D velocity structure verified with the broad-band (0.1-10 Hz) numerical ground motion simulation of the 2021 Kartal-Istanbul earthquake. The simulated PGAs agree with the ground-motion prediction equations for short epicentral distances (<30 km). Furthermore, according to the empirical relation for Turkish earthquakes, the maximum PGA value of the synthetic models (similar to 0.3 g) corresponds to the felt intensity of MMI IX. The simulated spectral accelerations for the M-w 5 earthquake scenarios may exceed the design spectrum between 0.2 and 0.6 s given in the Turkish Building Earthquake Code (2018). In addition, certain models also generate spectral accelerations close to the design-level spectrum between 0.4 and 1 s, leading to resonance phenomena. The results indicate that a moderate event (M-w 5) in the Istanbul metropolitan area is capable of damage potential for the mid-rise buildings (4-10 stories) because of the site condition with resonance phenomena and poor construction quality.Öğe Fault-controlled gas escapes in the shelf sediments of the Saros Gulf, NE Aegean Sea(TUBİTAK, 2021) Önder, Şebnem; Görür, Naci; Polonia, Alina; Gasperini, LucaHigh-resolution marine seismic reflection studies on the eastern shelf of the Saros Gulf have revealed the presence of gas-charged sediments across a narrow submarine valley incised by the Ganos Fault along the North Anatolian Fault system. Quaternary sediments, accumulated during glacial and interglacial periods through transgressional and progradational units, were controlled by glacio-eustatic sea-level fluctuations and tectonic deformation. The transgressional units made of upward-fining deposits created seals at their tops to form gas accumulation pockets. Conversely, the progradational units appear heavily eroded at their top, which is unfavorable for gas accumulation. The sediment’s gas accumulation features include enhanced reflections, acoustic blanking (or blanket), acoustic turbidity, acoustic curtain, and acoustic columns. In contrast, the gas escape features consist of acoustic plumes, cloudy turbidity, domes, and pockmarks. Their concentration along the Ganos Fault indicates that active deformation, punctuated by large magnitude earthquakes, has played an essential role in their formation, storage, and seep. Understanding these interactions may provide valuable contributions to hydrocarbon explorations and early-warning strategies against earthquake risk.Öğe Uplift of the western Anatolia and its relationship with crustal deformation(Springer Science and Business Media Deutschland GmbH, 2021) Komut, Tolga; Pürçek, İlkerA peneplain plateau, as a primary evidence for a recently elevated topography, represents the top surface of the western Anatolian crust that is deforming under an extensional regime. Vertical (up-flow) support of the hot mantle beneath the western Anatolia is responsible for the elevation of the crust. Residual topography anomaly models which indicate uplift of the crust and hence dynamic support of the mantle to the crust were calculated using useful sets of crustal thickness data. A distinct anomaly of a new residual topography model based on receiver functions in Anatolia marks an exhumed metamorphic core complex in the region. Mantle flow beneath the west Anatolian region is probably responsible for extensive exhumation of the metamorphic core complex and distributed extension in N–S direction. GPS velocities’ smooth differentiation indicates uniform diffusivity. Residual topography anomaly, which is one of the important pieces of evidence of the uplift, can also be compared with velocities related to diffuse N–S crustal extension in the region. Various pieces of evidence suggest strong relationships between the mantle dynamics, increased elevation, and extension of the crust in western Anatolia.Öğe New insights into the dynamic characteristics of alluvial media under the earthquake prone area: a case study for the Çanakkale city settlement (NW of Turkey)(Springer Science and Business Media Deutschland GmbH, 2021) Büyüksaraç, Aydın; Bekler, Tolga; Demirci, Alper; Eyisüren, OnurÇanakkale is a settlement located in the northwest of Turkey with relatively low strength soils under high seismic hazard. The depth of the bedrock was calculated based on microtremor measurements as the resonance frequency was variable, and a correlation was obtained by performing regression analysis based on the exponential variation trend curve. At the same time, resonance frequency values obtained from Çanakkale soils were recalculated as variables with 30 depth-resonance frequency correlations obtained before. The variation of the regression coefficients with the depths of the basin was examined. Especially, it has been observed that a-coefficient can be grouped with four different depths based on value ranges.Öğe Geodynamics of East Anatolia-Caucasus Domain: Inferences From 3D Thermo-Mechanical Models, Residual Topography, and Admittance Function Analyses(John Wiley and Sons Inc, 2021) Şengül Uluocak, Ebru; Göğüş, Oğuz H.; Pysklywec, Russell N.; Chen, BoWe investigate anomalous topography in the Anatolia-Caucasus domain of the Arabian-Eurasian plate convergence zone. To achieve this aim, we use three-dimensional (3D) geodynamic modeling in addition to analyses of the non-isostatic components of surface topography based on residual topography and free-air gravity admittance functions. The numerical experiments are based on two different temperature models obtained from P-wave tomography data that are sensitive respectively to large and small-scale variations of upper mantle structures. Our results suggest a long-wavelength convective support of topography, which is in general agreement with the uncompensated pattern of residual topography and free-air admittance values, as well as previous modeling studies. At shorter wavelengths, we provide new constraints on the regional dynamic processes related to 3D variations of the upper mantle flow vectors and associated surface deflections. Positive dynamic topography is found over the East Anatolian Plateau (∼400 m to ∼1.2 km) that is consistent with inferred lithospheric thinning processes pertinent to the tectonic evolution of the Tethyan orogenic system. We further show dynamic topography in the plateau (≥500 m) that may account for extensional tectonics in the Lake Van region interpreted from local kinematic and geophysical studies. In conjunction with the observations, negative anomaly patterns are estimated in the western part of the Black Sea (∼−2 km), the eastern Pontides arc (∼−200 m), and the northeast Arabian Plate (∼−1 to −2.3 km). Our model results also suggest a link between large-scale mantle flow and SW-NE-directed general pattern of the SKS-based anisotropy beneath the region. © 2021. American Geophysical Union.Öğe The inferences on the Aegean geodynamic context from 30 October 2020 Samos earthquake (Mw:6.8)(Elsevier, 2021) Över, Semir; Özden, Süha; Demirci, Alper; Gündoğdu, ErdemOn October 30, 2020, an earthquake with a magnitude of 6.8 (Mw) struck the northern coast of Samos Island in the Kuşadası Gulf. The solution to the focal mechanism indicates that the earthquake of 30 October 2020 occurred on a normal fault with nodal planes of E-W strike; thus, indicating extension in N-S direction. The fault plane solutions show a N-S trending extension for normal faults, which are obtained by inverting the moment tensor waveforms of 23 earthquakes and the P-wave first motion polarities of 11 aftershocks. A normal fault stress regime of approximately N-S (N6°E) σ3 axis is given by the inversion of slip vectors measured at sites located on land in Kuşadası. The mean R value is 0.84, suggesting that the stress regime is triaxial extensional stress state. The inversion of the focal mechanism of earthquakes occurring on land and in the Gulf of Kuşadası describes an extensional stress regime active today, characterized by an approximately N-S (N9°E) σ3 axis. The calculated R value of 0.31 indicates a triaxial stress state. For the 30 October 2020 earthquake (Mw:6.8), the Coulomb failure stress change analysis shows a substantial reduction in stress in the N-S direction supporting the kinematic results. The N-S extension in Western Anatolia-Aegean is largely influenced by the relatively fast movement of the Hellenic trench southwards, related to the sinking of the African plate beneath Aegean.Öğe Co-seismic beachrock deformation of 8th century AD Earthquake in Middle Strand of North Anatolian Fault, Lake Iznik, NW Turkey(Elsevier, 2021) Erginal, Ahmet Evren; Erenoğlu, Ramazan Cüneyt; Yıldırım, Cengiz; Selim, H. Haluk; Kıyak, Nafiye Güneç; Erenoğlu, Oya; Ulugergerli, EminA historical earthquake-related co-seismic deformation observed on beachrock beds along the southern shoreline of Lake Iznik is discussed as a new paleoseismic record for an 8th century AD earthquake in the Middle Strand of the North Anatolian Fault, NW Turkey. Electrical Resistivity Tomography (ERT) images beneath the beachrock surface allowed monitoring of the subsurface trace of a normal fault dipping north along a 100 m surface rupture. No strike-slip deformation exists along the rupture, suggesting that the deformation in the beachrock is connected with a secondary structure, and that the main surface rupture was under the lake waters. The deformed beds of the beachrock, dated using Optically Stimulated Luminescence (OSL) to 1.3 ± 0.15 ka, are overlain by an undeformed secondary deposition of beds dated to 1.2 ± 0.09 ka. This allows us to narrow down the time of the faulting and implying that it was most likely a result of the AD 715 earthquake.Öğe Imaging the tectonic components under the Eastern Mediterranean and Black Sea with gravity (satellite) data(Maden Teknik Arama Genel Müdürlüğü, 2021) Toker, Ceyhan Ertan; Ulugergerli, Emin UğurTectonic structures in the Black Sea and the Levantine Sea were mapped using satellite gravity data. The relationship between Antalya and Cyprus arcs is revealed by the deformation traces of the arc formation. The Cyprus arc which over the slice that disappears from the South of the Anaximander seamounts to the Northeast, can traceable at the western end of the Antalya Bay. The distinction of western and eastern basins in the Black Sea is also mapped. Due to the low spatial resolution, additional studies with higher resolution are required.Öğe Paleo-earthquake evidence and earthquake recurrence for Düzce fault, Turkey(Springer, 2021) Komut, Tolga; Karabudak, ErsinPaleoseismological trenching was performed along the Duzce fault providing some preliminary insight about its seismogenic behavior. Dating was based on radiocarbon analysis of peat samples collected from the trenches and suggested seven earthquakes have occurred since 1740 BC. Integrating date constraints of events exposed in the trenches suggests a periodical earthquake recurrence model. According to a linear sequential event serial that has minimum misfit determined by considering the probability curve limits of the sample dates, the earthquake recurrence interval is between 384 and 460 years (or possibly between AD 394 and 400). A probability curve was also calculated for the date of the last earthquake (1999 Duzce earthquake) considering the probability distributions of sample dates based on the same event serial. This probability-distribution-based method, similarly, predicted that the 1999 Duzce earthquake occurred between 1933 and 2005 (+/- 36 years) with a 68% probability. After this verification, using this method, it was estimated that the next earthquake along the Duzce fault has a 68% probability of occurring between 2328 and 2392. According to this calculation, the earthquake recurrence interval is about 391 +/- 34 years with a 68% probability and the AD 967 historical earthquake likely ruptured the Duzce fault. Assuming an average slip of 350 cm (the average slip of the 1999 earthquake), the slip rate was estimated to be between 8.7 and 11.2 mm/a.Öğe Deprem Kültürü ve Farkındalık Çalışmaları: Şili ve Elazığ Depremlerinin Karşılaştırılması(Çanakkale Onsekiz Mart Üniversitesi, 2020-12-31) Yolcu, Mehmet; Bekler, TolgaYerküre kendi iç dinamikleri ile birçok yeriçi kaynaklı doğal döngünün ev sahibidir. Depremlerde bu doğal döngünün bir sonucu olan yer hareketleridir. Bu hareketlerin farklı ölçekteki küçük ve büyük etkileri her zaman afetlerin en önemli unsuru olmuştur. Yıkım etkileri nedeni ile depremler savunmasız toplumlar karşısında ciddi can ve mal kayıpları oluşturmaktadır. Dünyada yıkıcı depremlerin önemli bir kısmı genelde levha sınırlarında olmaktadır. Türkiye de tektonik konumu ile bu levhaların göreceli hareketinden oldukça etkilenen ve yoğun sismik hareketlin yaşandığı ülkelerden birisidir. Dünyanın en yıkıcı depremlerinin yaşandığı Şili’de yine bu tektonizmanın en çok tahrip ettiği ülkelerin başında gelmektedir. Farklı tektonik levhaların tehdidi altında olan Türkiye ve Şili’de meydana gelen depremlerin ekonomik, toplumsal ve yapısal etkileri çoğu zaman depremlerin özelliklerine göre de değişken olabilmektedir. Bununla beraber aynı büyüklükte iki depremin oluşturduğu etki de farklı olabilmektedir. 24 Ocak 2020 Elazığ (Mw=6.8) ve 1 Ağustos 2019 San Antonio-Şili (Mw=6.8) depremleri bu argümana iki örnek deprem olarak incelenmiştir. Özellikle deprem öncesi afete hazırlık ve deprem sonrası kriz yönetimi aşamaları yanında müdahale ve iyileştirme aşamalarında depremlerin yıkıcı karakterine bağlı nasıl irdelenmesi gerekliliği öne çıkabilmektedir. Dünyadaki model ülkeleri incelediğinde geçmişte yaşadıkları büyük depremler milat noktası olmuştur. İncelenen bu iki depremde toplumların istek ve katılımı ile kamusal yönetim anlayışının deprem kültürüne göre oluşturulduğu görüşü hâkim olmaktadır. Bu durum depremler konusunda farkındalığın uygulama ve deprem zararlarının azaltılması aşasında oldukça önemli bir rol oynadığını da göstermektedir.
