Jeofizik Mühendisliği Bölümü Koleksiyonu

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https://hdl.handle.net/20.500.12428/2667

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Resistivity image of the Lokbatan Mud Volcano
(Elsevier, 2025) Gasimov, Elnur; Peksen, Ertan; Durdağ, Doğukan; Salamov, Avaz; Najafov, Orkhan; Ulugergerli, Emin Uğur
The shallow structure of the Lokbatan mud volcano region was explored via direct current resistivity method. Primary focus was on investigating the thickness of mud volcano material along the volcano vent and its surroundings. Vertical electrical sounding (VES) data were measured using a Schlumberger electrode array. A twodimensional (2D) inverse solution was applied to the VES data of each profile. The results of the 2D inverse solution show the presence of 10-30 Omega-m of dried mud volcano material at the surface of the study area and lower resistivity stratified structures towards depth. Consequently, the shallow 2D/3D geoelectric image of the volcano vent and the thickness of the mud volcano material (breccia) distributed along the perimeter were successfully revealed.
Soil remediation at coastal plains with the help of DC Resistivity Method
(Maden Tetkik Ve Arama Genel Müdürlüğü-MTA, 2025) Özentürk, Buse; Karaca, Öznur; Ulugergerli, Emin Uğur
The coastline of the Dardanos, a district of & Ccedil;anakkale, T & uuml;rkiye, suffers from saltwater intrusion due to excessive extraction of groundwater for domestic usage and also agricultural activities. Thus, the salinity level increased, and much of the land became unusable. The electrokinetic remediation method was employed to reduce the salinity level in the soil samples in laboratory conditions. The sample used in remediation is silty agricultural soil, with pH value and electrical conductivity (EC) of which are 8.33 and 1282 mu S/cm respectively. In the lab-scale experiments, three different types of electrodes, aluminum, copper, and galvanized steel, were used in the tests. For each type of metal, electrode pairs were placed in the soil that was filled in a plastic container. Current variation was monitored while 1 VDC/cm was applied to electrodes. Average electrical conductivity reduces to 13.5%. As a side effect, all electrodes suffered from heavy corrosion which may be prevented by using anti-corrosion additives to reduce damage for future applications.
Makine Öğrenmesi Algoritmalarının Türkiye Depremlerinde P ve S Fazlarının Belirlenmesindeki Etkinliği
(Afet ve Acil Durum Yonetimi Baskanligi (AFAD), 2025) Ünal, Utku; Bekler, Tolga; Bekler, Feyza Nur
Depremlerin dinamik parametrelerinin belirlenmesine yönelik analizlerde sismik cisim dalgalarının (P ve S fazları) varış zamanlarının doğru tespiti, sismolojik problemlerin çözümünde bir ön koşuldur ve varış zamanlarını temel alan çalışmalara, örneğin yer içi kabuk/manto yapısının anlaşılması gibi ve çeşitli araştırma alanlarına katkıda bulunur. Makine öğrenimi veya daha geniş ve bilinen uygulaması ile yapay zekâ teknolojilerindeki son gelişmeler, sismogramlar kullanılarak cisim dalgalarının varış zamanlarının otomatik olarak tespit edilmesini mümkün kılmaktadır. Türkiye, Avrasya, Afrika ve Arap levhalarının kesişim noktasında yer aldığı için karmaşık tektonik yapısı nedeniyle yüksek sismik aktiviteye sahiptir. Bu çalışmada, KRDAE (Kandilli Rasathanesi ve Deprem Araştırma Enstitüsü) ağına ait 2013-2019 yılları arasındaki Türkiye’de meydana gelen deprem kayıtlarında P ve S fazlarının geliş zamanlarını otomatik olarak tespit eden derin öğrenme algoritmasının başarımı değerlendirilmiştir. Sonuçlar, makine öğrenmesinin geleneksel istatistiksel yöntemlere kıyasla daha doğru tahminler yapabildiğini ve insan kaynaklı hataların azaltılmasında etkili olduğunu göstermektedir. Çalışmada elde edilen bulgular, büyük veri tabanlarıyla eğitilmiş derin öğrenme tabanlı sismik faz tespit algoritmalarının, yerel ihtiyaçlara uygun hale getirilmesiyle sismolojik analizlerde doğruluk ve hız artışı sağlayabileceğini ortaya koymaktadır. Gelecekteki çalışmalarda, yerel veriyle de eğitilmiş modellerin karşılaştırmalı olarak incelenmesi ve faz tespitinde uzman müdahalesine ihtiyaç duymayan algoritmaların geliştirilmesi önerilmektedir.
Reservoir characterisation of compacted sandstones in the Osmancık Formation, Thrace Basin, Türkiye
(EAGE Publishing BV, 2025) Arpacı, Taner; Yılmaz, İsmail Ömer; Akın, Serhat; Ulugergerli, Emin Uğur
The Thrace Basin houses the main gas-producing fields of Türkiye. The gas reservoirs in the basin are mostly located in deltaic sediments of the Oligocene Osmancık Formation where the hydrocarbon-bearing sandstone reservoirs generally reflect class 3 type of amplitude-versus-offset (AVO) anomalies. Our results indicate that AVO behaviour changes from Class 3 to Class 2 response due to the ascending compaction trend of the lithology with increasing depth. Acoustic impedances (AI) show an abrupt increase, because of higher compaction of the sandstones of the Osmancık Formation. Bright spots are the distinctive characteristics of gas sands encased in shale lithology in seismic stack sections. However, at higher depths of the Osmancık Formation, sweet spots tend to disappear due to lower porosity and permeability at the producing reservoir intervals. We propose a workflow to integrate pre-stack seismic analysis and lithology prediction of the field to characterise the gas-producing reservoirs. Spatial distribution of gamma ray values obtained with neural network prediction indicates highly lateral variation of shaliness, which is directly related to reservoir quality in the deeper Osmancık Formation. Therefore, diagenesis in sandstones and increase in shaliness play a crucial role in terms of evaluation of petrophysical properties of the reservoir, such as porosity and permeability.
Detection of P and S Wave Phases by Machine Learning using Northwestern Türkiye Local Seismic Network Data
(Birkhauser, 2025) Ünal, Utku; Bekler, Tolga
In regions with intense seismic activity like earthquakes, rapid detection and resolution of earthquake parameters and understanding seismic activity and mechanisms are important in terms of reducing possible risks. Since this process is left to the knowledge and experience of users to a great extent in the solution stage, human errors in detection of seismic wave phase arrival times may negatively affect the reliability of model studies. In this study, machine learning, which has been successfully applied to data in various seismological fields, was applied to earthquakes occurring in the Biga Peninsula, encompassing the most complicated tectonic elements of the north-western Aegean region, has high window seismicity. Results were evaluated using the waveform database for events recorded by local (COMU—Çanakkale Onsekiz Mart University) and national (KOERI—Kandilli Observatory and Earthquake Research Institute, AFAD—Ministry of Interior Disaster and Emergency Management Presidency) seismic networks observing activity linked to tectonism in the region under consideration with the originally trained model of the PhaseNet machine learning algorithm. Data contains 918 earthquakes recorded at 118 stations from May 2020 to the end of 2021. Compared to classic methods, the machine learning model used in the study provided more accurate results for detecting P and S wave phases. Also, epicentre calculations based on machine learning algorithm appear to be in better spatial agreement with the distribution of active faults than calculations based on handpicks. Although the original model of PhaseNet has not been trained with local data from Türkiye, study shows it is possible to get meaningful results by making adjustments on the algorithm or applying signal processing techniques on the data. Study suggests that enhancing machine learning algorithm with local training data can improve phase detection accuracy and epicenter prediction in seismic studies. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.
Yer Bilimlerinde Modellemeye Genel Bir Bakış; Çevre Jeofiziği Uygulamalarından Çıkarımlar
(Tmmob Jeoloji Mühendisleri Odası, 2024) Uluocak, Ebru Şengül; Ulugergerli, Emin Uğur
Yer bilimleri ile ilgili bir araştırmada, jeolojik veya mühendislik problemlerini incelerken, modelleme çalışmaları iki aşamalı olarak işlev görmektedir; i) arazi çalışmasından önce ölçüm parametrelerinin elde edilmesi (kavramsal model) ve ii) arazi çalışmasından sonra, kavramsal model yardımıyla tahmini yeraltı modelinin doğruluğunun kontrol edilmesi. Sayısal modelleme süreci her iki aşamada da tek başına yeterli olmamakla birlikte, disiplinler arası çalışmalardan elde edilen ek bilgilerle sayısal modellerin gerçekçi bir yeraltı yapısına yakınsaması mümkündür. Bu makalede yerbilimlerinde kullanılan modelleme çalışmaları ile ilgili bir iş akışı tanımlanmıştır ve Çanakkale (Türkiye) eski düzensiz katı atık depolama alanında gerçekleştirilen bir çevre kirliliği araştırması bu iş akışı takip edilerek sunulmuştur. Buna göre, kavramsal bir modele göre belirlenen doğrultularda elektrik özdirenç yöntemi ile tomografi ölçüleri alınmış, çalışma alanın yeraltı özdirenç yapısından gözeneklilik kesiti elde edilerek, varsayımsal iki boyutlu (2B) sayısal birleşik kirlilik iletim modeli üretilmiştir. Sonuçlar, jeofizik ölçümlerin yapıldığı yıllar (2004, 2008 ve 2009) ve sayısal modelleme zamanı (13,6 yıl) boyunca depolama sahasından kaynaklanan kirliliğin mekânsal ve zamansal değişimini göstermektedir. Ayrıca, sayısal modelleme sonuçları, olası araştırma profilinin uzunluğu ve derinliği ile (sırasıyla, ~40-250 m ve 0-25 m), ileride bu bölgede yapılabilecek kirlilik çalışmaları için kavramsal bir model sunmaktadır. Sonuçlar, açık atık depolama alanı gibi kirletici bir kaynaktan yayılan kirlilik bulutunun uzamsal ve zamansal yayılımına duyarlı sayısal modeller ve jeofizik çalışmaların birlikte değerlendirilmesinin önemini göstermektedir.
2D nonlinear inversion of DC resistivity measurements, a case study; southeastern part of Ras El Dabaa, Northwestern coast, Egypt
(Springer, 2024) Zarif, Fardous; Barseem, Mostafa; Elshenawy, Ahmed; Ulugergerli, Emin Uğur
The southern Mediterranean coast suffers from limited water resources as a result of exploitation of water supply, population growth, and climate change. Spatial lineaments and Seawater Intrusion (SWI) were detected at the southeast portion of Ras El Dabaa, on Egypt's northwest coast, using the direct current resistivity (DCR) method. The Vertical Electrical Sounding (VES) data were acquired using Schlumberger array along four profiles and inverted both independently and jointly, aiming to obtain Two Dimensional (2D) geoelectrical images. The results of the one Dimensional (1D) inversion of VES data at each profile were stitched to form pseudo-2D sections on which the resistivity values and aquifer thickness in the southwest of the region appeared to be generally increasing, indicating a potential improvement in water quality.However, the results did not fully image the lateral variation but focused on the horizontal boundaries of the subsurface. On the contrary, the results of 2D inversion of the same data sets successfully managed to provide images that depicted resistivity distribution in both lateral and vertical directions. The detected sets of lineaments and fractured zones within the oolitic limestone and fossiliferous limestone units control the occurrence of groundwater in the region. The 2D inversion scheme revealed a low resistivity zone that indicated the presence of SWI and/or the dissolution of marine salts from the marine limestone bedrock of these aquifers in the northern portions of the studied area. Additionally, analysis of the 2D apparent porosity section shows how aquifers are connected by secondary porosity, which is defined by structures that resemble channels. The current approach offers valuable structural information for future planning and development of such complex geological coastal locations, taking into consideration the vulnerability of the groundwater system.
A Discussion on Geodynamic Modeling Methodology: Inferences from Numerical Models in the Anatolian Plate
(Tmmob Jeoloji Mühendisleri Odası, 2024) Şengül Uluocak, Ebru
Numerical models have found widespread use in geosciences, mainly due to high-resolution datasets and the development of supercomputing facilities with powerful data processing and storage capabilities during the past two decades. Instantaneous and time-dependent geodynamic modeling studies were carried out in many regions of the Alpine-Himalayan orogenic belt, including the Anatolian Plate, to investigate mantle dynamics such as lower lithosphere deformation, upper mantle flow, and their surface implications. This study focuses on the instantaneous numerical modeling technique by considering multidimensional thermomechanical models in the Central and East Anatolian plateaus. To this end, conventional geodynamic modeling processes are explained with a conceptual flow chart that shows a feed-forward backpropagation modeling architecture which is nonlinearly fed by a large parameter space. While addressing a complex natural phenomenon controlled by variables on a wide range of space-time scales, the limitations as well as advantages of numerical models are analyzed. In addition to conventional techniques, systematic data improvement is discussed as a new strategy in data/ parameter-dependent numerical model design through an iterative process based on the Grounded Theory method for the construction of an explanatory theory from the model. This involves not refinement but (re)construction of the data (i.e., measurement/analysis/scaling) as an effective way to reveal theory/information grounded in data. It is speculated that this procedure, which includes problem-oriented data reconstruction accompanying the numerical modeling process, may provide an integrated perspective for instantaneous numerical modelling.
Biga Yarımadasında Jeodeğerler ve Jeoturizm Potansiyeli
(TMMOB Jeoloji Muhendisleri Odasi, 2018) Çalık, Ayten; Kapan, Sevinç; Erenoğlu, Ramazan Cüneyt; Erenoğlu, Oya; Yaşar, Cumali; Ulugergerli, Emin Uğur
It 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.
Neotectonics of Türkiye and its geothermal implication
(Maden Tetkik ve Arama Genel Müdürlüğü-MTA, 2023) Görur, Naci; Önder, Şebnem
Favourable conditions for geothermal energy were created in Turkey during its neotectonic episode from Neogene to Quaternary. This episode is characterized mainly by fluvio-lacustrine sedimentation and strike-slip tectonics with associated magmatism. Under these conditions, a great number of geothermal areas have formed in the neotectonic provinces in association with major tectonic features, including the North and East Anatolian Fault Zones (NAFZ and EAFZ, respectively). Today, the geothermal resources of Turkey are mainly located in the West Anatolian Extensional Province associated with the graben systems. However, the Central Anatolian Ova Neotectonic Province is considered as one of the most promising geothermal targets which are characterized by the presence of widespread hot dry rock systems. This study mainly aims to throw light on the possible potentiality of these resources at Kırşehir Block by emphasizing the neotectonic evolution of the country.
The Role of Upper Mantle Forces in Post-Subduction Tectonics: Plumelet and Active Rifting in the East Anatolian Plateau
(Amer Geophysical Union, 2024) Şengül Uluocak, Ebru; Pysklywec, Russell N.; Sembroni, Andrea; Brune, Sascha; Faccenna, Claudio
The spatiotemporal interaction of large- and regional-scale upper mantle forces can prevail in collisional settings. To better understand the role of these forces on post-subduction tectonics, we focus on mantle dynamics in the East Anatolian Plateau, a well-documented segment of the Arabian-Eurasian continental collision zone. Specifically, we analyze multiple forces in the upper mantle, which have not been considered in previous studies in this region. To this end, we use a state-of-the-art 3D instantaneous geodynamic model to quantify the dynamics of thermally defined upper mantle structures derived from seismic tomography data. Results reveal a prominent SW-NE-oriented mantle flow from the Arabian foreland to the Greater Caucasus–a plumelet–through a lithospheric channel under the East Anatolian Plateau. This plumelet induces localized dynamic topography (∼500 m) around the extensional Lake Van province, favoring NE-directed compression and westward escape of the Anatolian plate. We suggest that the Lake Van region is an active magma-rich intraplate rift in the Africa-Arabia-Anatolian plume-rift system. The rift zone was probably initiated by Neotethyan subduction-related forces and has been reactivated and/or sustained by the plumelet-induced convective support. Our findings are consistent with numerous observations, including the recent low-ultralow seismic velocities with a SW-NE splitting anisotropy pattern, geochemical and petrological studies, and local kinematics showing upper mantle-induced extensional tectonics in the collisional region.
Multistage lithospheric drips control active basin formation within an uplifting orogenic plateau
(Nature Portfolio, 2024) Andersen, A. Julia; Göğüş, Oğuz Hakan; Pysklywec, Russell N.; Şengül Uluocak, Ebru; Santimano, Tasca
According to GNSS/INSAR measurements, the Konya Basin in Central Anatolia is undergoing rapid subsidence within an uplifting orogenic plateau. Further, geophysical studies reveal thickened crust under the basin and a fast seismic wave speed anomaly in the underlying mantle, in addition to a localised depression in calculated residual topography (down to 280 m) over the Konya Basin, based on gravity-topography considerations. Using scaled laboratory (analogue) experiments we show that the active formation of the Konya Basin may be accounted for by the descent of a mantle lithospheric drip causing local circular-shaped surface subsidence. We interpret that the Konya Basin is developing through a secondary drip pulse that is contemporaneous with broad plateau uplift caused by a larger-scale lithospheric drip since the Miocene. The research reveals that basin evolution and plateau uplift may be linked in a multistage process of lithospheric removal during episodic development of orogenic systems. Active subsidence of the Konya region, Turkiye, is attributed to descent of a lithospheric drip into the mantle, according to analogue models, and suggests that major tectonic events may be linked to multistage dynamic flow processes in the mantle.
Tectonic implications of the February 2023 Earthquakes (Mw7.7, 7.6 and 6.3) in south-eastern Turkiye
(Elsevier, 2023) Över, Semir; Demirci, Alper; Özden, Süha
The series of earthquakes that took place on February 6, 2023 caused one of the saddest major calamities in Turkiye. The first major earthquake of magnitude Mw7.7 broke the Pazarcik and Erkenek segments moving north on the East Anatolian Fault Zone (EAFZ) between Turkoglu and celikhan. According to the Coulomb failure criterion, the Pazarcik earthquake (Mw7.7) increased stress on the Surgu-cardak Fault, a segment on the north splay of the EAFZ, and nine hours later the Elbistan earthquake (Mw7.6) occurred. This great event ruptured the cardak Fault, the western part of the E-W trending Surgu-cardak Fault between Nurhak and Goksun. The Amanos Fault, which extends from Turkoglu south to Antakya, broke almost simultaneously to the first Pazarcik earthquake. Similarly, the earthquake that broke the Amanos Fault transferred increased stress to its southwestern neighbour, the Cyprus-Antakya Transform Fault, triggering the 6.3 magnitude Samandag earthquake 14 days later. The February 2023 earthquakes, which caused the collapse of >100,000 buildings and the death of >50,000 people, created surface ruptures hundreds of kilometres in length and caused different displacements on different faults, the two largest of which were 4.6 and 6.7 m. On all the faults where the deadly earthquakes occurred in February 2023, inversion of the focal mechanisms of the earthquakes (main shocks and their aftershocks) indicates a transtensional stress regime, or a change from strike-slip to normal slip. For all strike-slip inversions, the R values are <0.45 indicating transtension. The stress tensors obtained indicate left-lateral movement with normal component on all faults where the earthquakes occurred. The transtensional regime, which is thought to reflect regional tectonics, is the result of forces caused by relative movements of Arabia, eastern Mediterranean and Eurasia.
Özel Gereksinimli Çocukların Aileleri İçin Afet Eğitim Programı
(Ankara Üniversitesi, 2024) Örenoğlu, Sultan; Bekler, Tolga
Bu araştırmada, özel gereksinimli bireylerin ailelerine yönelik afet eğitim programının geliştirmesi, uygulaması ve değerlendirmesi hedeflenmiştir. Ailelerin afet ve afet durumunda özel gereksinimli çocuğuna yönelik eğitim ihtiyacını belirlemek amacıyla ihtiyaç belirleme çalışması yapılmıştır. İhtiyaç analizi iki aşamalı yürütülmüştür. İlk aşamada 48 ebeveyne açık uçlu soru uygulaması yapılmıştır. İkinci aşamada açık uçlu soru uygulamasından elde edilen bulgulardan yola çıkılarak bir anket oluşturulmuş ve anket 150 özel gereksinimli çocuğu bulunan ebeveyne uygulanmıştır. Belirlenen ihtiyaçlar doğrultusunda özel gereksinimli bireylerin ailelerine yönelik afet eğitim programının amaçları, içeriği ve etkinlikleri oluşturulmuştur. 54 ebeveyn geliştirilen eğitim programına göre eğitime alınmıştır. Eğitim programının etkililiğinin değerlendirilmesi iki aşamalı olarak yapılmıştır. İlk aşamada eğitime katılan 54 ebeveyne afet bilgi testi ön-test, son-test olarak uygulanmıştır. İkinci aşamada ise eğitim sonunda, eğitime ilişkin değerlendirme anketi uygulanmıştır. Araştırma sonuçları göstermiştir ki; ebeveynlerin ihtiyaç önceliği özelde afet türleri (deprem, sel gibi) ve bu afet türünde yapılması gerekenler değildir. Ebeveynler genel anlamda afet durumlarında ne yapılması, nasıl davranılmasına gerektiğine odaklanmıştır. Afet türlerinde (sel, yangın, deprem gibi) yapılması gerekenlerin ise öncelik sıralamasında ikinci sıraya düşmüştür. Ön-test, son-test uygulama sonuçları özel gereksinimli bireylerin ailelerine verilen eğitim sonucu katılımcı ailelerin bilgi düzeylerinin arttığını göstermiştir. Ebeveynlerin eğitim sonunda katıldıkları anket sonuçları verilen eğitimden memnun oldukları ancak eğitimin daha çok örnekli olması ve bir miktar daha uygulamaya dönük olması yönünde düşünceleri olduğunu göstermiştir.
Meteorolojik Veriler Kullanılarak Deprem Tahmin Edilebilir mi?
(Afet ve Acil Durum Yönetimi Başkanlığı (AFAD), 2024) Uslan, Erdinç; Ulugergerli, Emin Uğur
Depremler ile meteorolojik veriler arasında bir ilişkinin bulunup bulunmadığı araştırmak için Ege Denizi özelinde büyüklüğü 4.0≤Mw≤7.0 depremler ile günlük ortalama sıcaklık, ortalama rüzgâr hızı, toplam yağış miktarı ve deniz suyu sıcaklığı değerleri karşılaştırılmıştır. Hava sıcaklığında ve deniz suyundaki değişimlerin depremin habercisi olduğu yönündeki haberler sosyal medyada ve ulusal basında sıklıkla görülse de depremlerin öncesini ve sonrasını kapsayan veriler ile yapılan incelemeler bu tür ilişkilendirmenin sadece rastlantılar ile açıklanabileceğini göstermektedir. Ege denizi özelinde büyüklüğü 4.0≤Mw≤7.0aralığındaki depremlerle meteorolojik verilerin arasında herhangi bir ilişkinin olmadığı görülmüştür.
Probabilistic Seismic Hazard Analysis of the Izmir Bay Area
(Springer Science and Business Media Deutschland GmbH, 2024) Albayrak, Kubilay; Askan, Ayşegül; Karagöz, Özlem; Tan, Onur
Probabilistic Seismic Hazard Analysis (PSHA) is an analysis that quantifies the probability of exceedance or the rate of various ground motion levels at a specific site or an area by using all the possible earthquakes. Since earthquakes are very intense in specific regions, it is important to identify the seismicity level of these areas. The Izmir Bay area is believed to be one of the most critical areas in Türkiye in terms of high seismicity. So, PSHA of the Izmir Bay area was constructed by using 34 SPAC locations which are used to obtain the average shear wave velocity of the upper 30 m (VS30). The diameter of the area to identify the seismic sources is selected as 200 km. Since PSHA mainly results in Peak Ground Acceleration (PGA) values as a quantifier of ground motion intensity measurement, PGA values are based on 15 different periods. Moreover, Response Spectrum results are based on 50-, 100-, 475-, 975-, and 2475-year recurrence intervals for mean in terms of 16%, 50%, and 84% quantiles. Finally, the seismicity contour maps based on 475- and 2475-year recurrence intervals are prepared based on PGA values to visualize the resulting seismicity of the specified region. Since the Izmir Bay area is mainly comprised of low VS30 values, the results of this study are believed to be important to take precautions for disaster resilience considerations.
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, Cengiz
This 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.
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, Ebru
We 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.
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, Kemal
Istanbul (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.
Fault-controlled gas escapes in the shelf sediments of the Saros Gulf, NE Aegean Sea
(TUBİTAK, 2021) Önder, Şebnem; Görür, Naci; Polonia, Alina; Gasperini, Luca
High-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.

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