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Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026/r/gumushane/12323
  Tectonic evolution of the Central Anatolian Crystalline Complex: Insights from using magnetic and gravity data

  Aktaş, Gülten

  This study investigates the inherited crustal architecture and concealed tectonic boundaries of the Kırşehir Massif, a key component of the Central Anatolian Crystalline Complex (CACC), using satellite-derived potential field datasets. Earth Magnetic Anomaly Grid 2 (EMAG2) magnetic anomalies and World Gravity Map 2012 (WGM2012) Bouguer gravity data were analyzed together with multiple edge-detection filters, including Total Horizontal Gradient (THG), Tilt Angle (TA), Theta Map (TM), and Tilt Angle of Horizontal Derivative Amplitude (TAHG), to enhance structural boundaries and identify subsurface discontinuities prior to geological interpretation. The enhanced magnetic and gravity fields reveal two principal lineament sets trending NW-SE and NE-SW, which coincide with major lithological contacts, fault zones, and the boundaries of the İzmir-Ankara-Erzincan Suture Zone (IAESZ) and Inner Tauride Suture Zone (ITSZ). Quantitative lineament classification based on azimuth and length statistics further confirms three dominant structural orientations (NW-SE, NE-SW, and E-W), reflecting both inherited suture-related structures and younger transtensional deformation. By integrating filtered anomaly gradients with regional geological constraints, this study provides the most detailed potential-field-based structural model of the Kırşehir Block to date and offers new insights into crustal inheritance, lithospheric segmentation, and the multi-phase tectonic evolution of Central Anatolia.

  İncele
• MakaleAçık Erişim2025/r/gumushane/19608
  Edge Detection Analysis Using EMAG2 Magnetic Data in Lake Van and Its Surroundings, Türkiye

  Aktaş, Gülten

  The aim of this study is to use EMAG2 magnetic data to analyze and interpret the boundaries of important structural features in and around Lake Van using various advanced edge detection techniques. The reduction pole was applied to the magnetic data. Edge detection is an important step to interpret the boundaries of geological structural elements with higher precision. A comprehensive lineament analysis was conducted by applying traditional and advanced edge-detection filtering techniques, including the Tilt angle (TA), the Tilt Angle of the Total Horizontal Gradient Amplitude (TAHG), and Total Horizontal Gradient-Based Edge Detection (THGED). With these methods, the boundaries of magnetic anomaly sources were tried to be interpreted more clearly. In these comparative results, lineations were obtained in the south of the lake and it was shown that it was affected by faults in the N-S, E-W main directions. In the north of the lake, NE-SW trending lineations were obtained.

  İncele
• MakaleYalnız künye2025/r/gumushane/14180
  Tectonic structures of Lake Eğirdir (SW Türkiye) revealed by magnetic analysis

  Aktaş, Gülten; Hisarlı, Z. Mümtaz; Öksüm, Erdinç

  Lake Eğirdir, located within the tectonically complex Isparta Angle of southwestern Türkiye, hosts an actively deforming transtensional basin shaped by multidirectional stresses. Although the surrounding fault systems have been studied previously, the subsurface fault architecture beneath the lake remained largely unresolved. Understanding the lake's subsurface tectonic framework is crucial for regional geological and seismic assessments. This study addresses this gap by applying traditional and advanced edge detection techniques to identify magnetic lineaments and assess their connection with surrounding faults using newly acquired high-resolution magnetic data, corrected for noise and distortions. The distinct magnetic lineaments identified confirm a structural connection on land with the regional fault network around the lake, also showing their continuity under the lake. The results reveal dominant NW-SE and E-W trending magnetic lineaments. The most prominent structure identified within the lake is a NE-SW fault that cuts the NW-SE anomalies and is spatially related to the Yaka Fault on land. Its continuation beneath the lake is confirmed by clustered seismicity and normal fault-type focal mechanisms, indicating active transtensional deformation. These findings highlight active faulting processes that continue to shape the lake basin and contribute to understanding regional seismic hazards. Integration of magnetic, bathymetric, seismic, and geodetic datasets reveals that Lake Eğirdir acts as a dynamic neotectonic transfer zone within the Isparta Angle, facilitating the westward extrusion of the Anatolian Plate.

  İncele
• MakaleAçık Erişim2024/r/gumushane/20131
  İzmit Körfezi manyetik verilerine kenar tespit yöntemlerinin uygulanması

  Aktaş, Gülten; Demirel, Sinan

  Marmara Denizi’nin kuzeydoğusunda yer alan İzmit Körfezi Kuzey Anadolu Fayı’nın kuzey kolu üzerinde olması nedeniyle sismik tehlike tahminleri açısından oldukça önemli etkilere sahiptir. Bu çalışmada İzmit Körfezi’nin yapısal çizgisellikleri yüksek çözünürlüklü manyetik veriler kullanılarak tanımlanmıştır. Başlangıçta verilere günlük düzeltme işlemi yapılmış ve gürültü etkilerini ortadan kaldırılmak amacıyla filtreler uygulanmıştır. Ayrıca, İzmit Körfezi’nin çizgiselliklerini ve yapısal unsurların sınırlarını çıkarmak için verilere birinci düşey türev, analitik sinyal, Tilt açısı, yatay gradyanın tilt açısı (TAHG), softsign fonksiyonu (SF) yöntemleri uygulanmıştır. Manyetik anomalilere neden olan yapısal unsurların belirlenmesinde TAHG ve SF filtreleri keskin ve net kenarlar oluşturmuştur. Tespit edilen çizgiselliklerin ana eğilimi körfezde D-B ve KD-GB yönündedir. Bu çalışmadan elde edilen bulgular sismik yansıma kesitleriyle de değerlendirilerek kesitlerdeki faylar ile çizgiselliklerin oldukça uyumlu oldukları görülmüştür. Böylece İzmit Körfezi’nin tektonik ve yapısal çerçevesinin daha iyi anlaşılması açısından manyetik sonuçlar güvenilir bir yapısal harita sunmaktadır. Çalışmadan elde edilen bölgenin çizgisellik haritası gelecekte yapılacak yeni araştırmalara katkı sağlayacağı açıktır.

  İncele
• MakaleYalnız künye2024/r/gumushane/13972
  Edge detection and depth estimation of Lake Sapanca, Eastern Marmara Region, from high-resolution magnetic data

  Aktaş, Gülten

  The present study aims to determine submarine structural elements by analysing high-resolution magnetic data sets and to examine the impact of geological surface structures characterizing Lake Sapanca. Lake Sapanca is located on the northern branch of the North Anatolian Fault Zone. The study area and its immediate surroundings are located within the most active tectonic structure of Turkey. A magnetic study was carried out in Sapanca Lake to reveal the structural elements that caused the formation of the lake. Diurnal corrections were applied to the magnetic data. During the analysis of the marine magnetic data set, there are variations in the mean field level of the magnetic field caused by the routing effects of ship noise on the measurements. To eliminate this noise effect, directional correction was performed. Then, de-stripping correction was also applied. It is essential to estimate the boundaries and depths of the structural features of the region. In order to elucidate the structural features of the region, different techniques such as tilt angle derivative, the total horizontal derivative of tilt angle derivative, Euler 2D deconvolution, horizontal gradient magnitude, and source edge detection were applied to magnetic data. 2-D modelling using GM-SYS in Oasis Montaj were performed. These techniques identified and mapped the edges of anomalous sources related to magnetic data corresponding to geological elements in the study area. The results allow us to image the submarine lineaments for the survey area. These structural lineaments are in E–W, NE–SW and NW–SE trends. These lineaments in our results are quite compatible with the faults in previous geophysical results. The E–W trending lineaments are related to the E–W trending faults in the region.

  İncele
• MakaleYalnız künye2023/r/gumushane/14532
  Interpretation of the tectonic structure of Gemlik Bay using magnetic data

  Aktaş, Gülten; Hisarlı, Z. Mümtaz; Demirel, A. Sinan

  The aim of this study was to determine the effects of the main faults and many small-scale faults and submarine structures within Gemlik Bay, on the middle strand of the North Anatolian Fault in the southeast of the Sea of Marmara. In order to produce a fault map for the study area and research tectonic structures, magnetic data were obtained using a cesium vapor magnetometer on a total of 30 profiles (340 km) with N-S and E-W orientation within the bay. Diurnal corrections were applied to obtain the necessary minimization of diurnal variations in the magnetic data. Heading correction and micro-leveling corrections were applied to remove small boat effects, and the reduction to the pole method was applied for greater differentiation of the magnetic data. Magnetic data were analyzed using advanced potential field processing techniques. Euler deconvolution technique was applied to define the extension and depth of the determined lineaments. Boundaries of structures in the region were determined using source edge detection, tilt derivative, the tilt angle of the total horizontal gradient amplitude (TAHG), and a novel edge detector based on the softsign function (SF) techniques. In order to reveal the tectonic evolution of Gemlik Bay, the structures obtained from the analysis results were interpreted and a fault map was produced. The results of the study identified the Armutlu Fault in the north, the Gemlik Fault in the east, the Zeytinbağı Fault and Mudanya Fault in the southwest and the Gençali Fault in the south within Gemlik Bay. These five essential faults significantly affected the region tectonically. These faults correlated well with the location of some previously-known major tectonic structures. Moreover, these important faults following the morphology of the bay indicate that Gemlik Bay was opened by a pull-apart basin mechanism.

  İncele
• MakaleYalnız künye2021/r/gumushane/14620
  High-resolution total field magnetic anomaly maps of Lake İznik (NW Turkey): assessment of faults which play important roles in tectonics of the lake

  Aktaş, Gülten; Hisarli, Z. Mümtaz; Demirel, A. Sinan

  In total, 380 km of marine magnetic data were processed and interpreted to reveal the main tectonic elements that control the formation of the lake. Lake İznik, which is an approximately rectangular-shaped active tectonic basin with 32 km length and 12 km width, is located between two segments of the North Anatolian Fault in the northeast Marmara region, Turkey. The purpose of this study is to identify the tectonic elements that played a role in the formation of Lake İznik with the help of new magnetic data and to reveal the tectonic evolution of the region by using other previously collected geophysical data. The Euler deconvolution, tilt angle, analytic signal and source edge detection methods were applied to the total field magnetic data for Lake İznik and its surroundings to determine the boundaries and depths to the source of magnetism. From the structural map obtained as a result of the review of this data, linearity in the magnetic data was detected along the NW–SE direction in the north of Lake İznik, N–S direction in the west and east, and E–W direction in the south. These lineaments were correlated with a limited amount of seismic data obtained from previous studies and were associated with faults. This linearity in NW–SE direction in the north was evaluated as the continuation of the Orhangazi fault and it is thought to play a significant role in the tectonic evolution of Lake İznik. When the results obtained from this study and the paleomagnetic results for the Eocene volcanic rocks in the study area are evaluated together, Lake İznik was connected with Gemlik Bay and the Marmara Sea during the Eocene–Pleistocene and Orhangazi Fault disconnected Lake İznik from Gemlik Bay in the Pleistocene–Holocene. It was deduced that the lake basin is a pull-apart basin developed up to the present day.

  İncele
• MakaleYalnız künye2015/r/gumushane/15657
  Tectonic evolution of the northern shelf of the Marmara Sea (Turkey): interpretation of seismic and bathymetric data

  Tur, Huseyin; Hoskan, Nihan; Aktas, Gulten

  This study is based on the geological interpretation of 250 km2 of multibeam bathymetric data coupled with 300 km of seismic profiles recorded on the northern shelf of the Marmara Sea offshore Büyükçekmece and Küçükçekmece Lagoons. The sea bottom morphology has a highly chaotic structure at the exit of the Büyükçekmece and Küçükçekmece lagoons. This chaotic surface structure is controlled by a basin-ridge system lying in the NE–SW direction at the exit of the Büyükçekmece Lagoon and by a relatively deep entrance observed at the exit of the Küçükçekmece Lagoon. In addition, the linear submarine slope parallel to the shoreline between the Istanbul Strait and the Küçükçekmece Lagoon is an important morphological structure of this area. The Istanbul Strait’s canyon on the northern shelf of the Marmara Sea and the elevated submarine plain west of this canyon are other important morphological structures observed at the sea bottom. The geologic interpretation of seismic profiles has allowed us to distinguish two seismo-stratigraphic units. The lower one is separated from the overlying units by a seismic sequence having a seismic facies from chaotic to parallel and the top represented by a high amplitude seismic reflector. Since these units get close to the sea bottom rising landwards, they are inferred to be the seaward continuation of the Oligocene–Upper Miocene units widely exposed on land. The upper unit, overlying the acoustic basement, whose parallel internal reflections onlap and downlap on the top of the acoustic basement, is interpreted as a Quaternary basin fill. Two groups of faults have been identified on seismic profiles and identified based on their characteristics in the study area. The first group consists of dip-slip faults trending NNE–SSW. These faults border the western slope of the Bosporus and the NNE–SSW trending basins offshore of the Büyükçekmece Lagoon. The second group of faults consists of NW–SE oriented strike-slip faults. These faults have created the linearities in the same direction at the sea bottom. As the result of comparison of these NW–SE-faults to the North Anatolian Fault Zone (NAFZ), this group of faults is likely to have a relation with the NAFZ. Therefore, it is considered that the mentioned faults may be reactivated in the region due to the stress created by the NAFZ.

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