Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Avoidance of Volunteering in Disasters Scale: A Scale Development and Validity Study (Methodological Study)
Öztürk, Serkan; Demirbilek, Ömer
Objective: Volunteers are a critical resource in disaster preparedness and response. This study aims to develop a valid and re liable measurement tool that can assess the reasons behind university students’ reluctance to volunteer in disaster situation. Material and Methods: The study was conducted using an exploratory sequential mixed method design. As a result of the thematic analysis of the semi structured interviews, seven themes were identified, and 81 items were formed. The items whose content validity was evaluated with the Law she technique were reduced to 64 and tested in a pilot study and nec essary adjustments were made. The final scale was applied to a sample group of 731 people who met certain criteria. The data were analyzed using SPSS 25.0 and AMOS 24.0 programs. Results: The scale was found suitable for factor analysis according to Kaiser-Meyer-Olkin (>0.60) and Bartlett’s test (p<0.05) results. As a result of exploratory factor analysis, 32 items with low factor loadings (<0.33) and over lapping content were eliminated; confirmatory factor analysis con firmed the structure of the scale consisting of 6 factors and 31 items. The fit indices (χ²/df=3.069, Comparative Fit Index=0.933, Goodness of Fit Index=0.893, Incremental Fit Index=0.933, Tucker-Lewis Index=0.925, root mean square error of approximation=0.053) were found to be acceptable. The Cronbach alpha value of the scale was 0.92 in total and ranged between 0.75 and 0.93 for the sub-dimensions. Conclusion: The developed scale stands out as a valid and reliable tool for assessing university students’ reluctance towards disaster vol unteering.
- MakaleAçık Erişim2026Orta Anadolu’da Manyetik Anomaliler, Volkanizma ve Depremsellik İlişkilerinin Jeofizik Analizi
Öztürk, Serkan; Dolmaz, M.Nuri; Kayin, Sercan
Orta Anadolu, aktif tektonik deformasyon ile volkanik faaliyetlerin birlikte gözlendiği önemli bir jeodinamik bölgedir. Bu çalışmada, Tuz Gölü Fay Zonu ve çevresindeki manyetik anomaliler, derin kabuksal yapılar ve depremsellik arasındaki ilişkiler bütüncül bir yaklaşımla araştırılmıştır. Bu amaçla NOAA tarafından geliştirilen EMAG2-v3 aeromanyetik veri setine Kutba İndirgeme (RTP), Analitik Sinyal (AS) ve Birinci Düşey Türev (FVD) filtreleri uygulanmış, manyetik kaynak derinlikleri hesaplanmıştır. Bölgenin güncel sismotektonik özelliklerini değerlendirmek amacıyla 1900–2026 yılları arasında meydana gelen lokal magnitüdü ML≥3.0 depremler kullanılarak Gutenberg–Richter büyüklük-frekans ilişkisi, b-değeri dağılımı ile deprem episantr ve odak derinliği analizleri gerçekleştirilmiştir. Sonuçlar, yüksek manyetik gradyan zonlarının özellikle Tuz Gölü Fay Zonu ve volkanik merkezler boyunca yoğunlaştığını, manyetik kaynak derinliklerinin yaklaşık 1.3–9.7 km arasında değiştiğini ve deprem odaklarının büyük ölçüde 5–15 km derinlik aralığında kümelendiğini göstermektedir. Ayrıca yüksek manyetik gradyan zonları, düşük b-değeri alanları (1.0<) ve deprem kümeleri arasında genel bir mekânsal uyum belirlenmiştir. Elde edilen bulgular, Orta Anadolu'daki aktif fay sistemleri, volkanik yapılar ve derin kabuksal süreksizliklerin birlikte değerlendirilmesinde manyetik yöntemlerin önemli bir tamamlayıcı araç olduğunu ve bölgenin tektonik ile magmatik evriminin anlaşılmasına katkı sağladığını ortaya koymaktadır.
- MakaleAçık Erişim2026Seismic potential in and around the Muş basin (Eastern Türkiye): Insights from stress analysis and statistical modeling; [Muş havzası (Doğu Türkiye) ve civarındaki deprem potansiyeli: Gerilme analizi ve istatistiksel modellemeden elde edilen çıkarımlar]
Şimşek, Ecenur Cansu; Alkan, Hamdi; Öztürk, Serkan
In this research, current and near-future potential earthquake zones in and around Muş basin (eastern Türkiye) are investigated using the instrumental period earthquake catalog and focal mechanism parameters of local earthquakes. For this purpose, the relationships between the b-value distributions and the Colulomb stress changes are interpreted with different depth ranges (5 to 25 km). Also, for a reliable prediction, the occurrence probabilities, recurrence periods of earthquakes, and the Z-value distribution (seismic quiescence areas) are taken into consideration. 15,722 earthquakes with moment magnitudes with 0.8≤Mw≤6.9 between the latitudes of 38.2°N-39.6°N and longitudes of 40.0°E-43.0°E, over a period of ~90.63 years between November 12, 1934, and June 30, 2025, are used for all statistical analyses. Completeness magnitude, Mc-value is accepted as 2.5±0.5. The b-value is determined to be 0.780 ± 0.04, which is smaller than the average (b = 1.0). Additionally, twenty local events with magnitudes greater than Mw≥4.8 are selected to image the Coulomb stress changes. The occurrence probabilities of earthquakes with Mw=5.5, 6.5, and 6.9 in 10 years are predicted as ~83%, ~27% and ~15%, respectively. Recurrence periods of events with these magnitudes are estimated as ~13, ~32, and ~63 years, respectively. Large Z-values are detected in the Kargapazarı segment, Bingöl province, and west of the Kulp and Kozluk segments. Additionally, the analyses of b-value and Coulomb stress change used for hazard prediction reveal a decreasing b-value and an increasing stress change around the Karlıova Triple Junction at a depth of approximately 10 km. Finally, these seismotectonic parameters can represent the possible locations for earthquake occurrences in the near future.
- MakaleYalnız künye2026Tomography of the source zone of the February 6, 2023, Kahramanmaras, Earthquake Doublets of Southern Anatolia
Salah, Mohamed K.; Alkan, Hamdi; Öztürk, Serkan; Güney, Recep
On February 6, 2023, two destructive earthquakes and many posterior aftershocks hit the Kahramanmaras,area in southern Anatolia. The Kahramanmaras, earthquake sequence (KMES) caused extensive damage and economic losses in T & uuml;rkiye and Syria. In this study, the 3-D crustal seismic velocities surrounding the hypocentral region of the KMES are determined using a large dataset of body wave arrival times obtained from local earthquakes. To better constrain the physical properties and seismogenic behavior of the KMES source region, the Vp/Vs ratio is calculated and correlated with Poisson's ratio using the obtained velocity models. To gain a better understanding of the stress conditions and regional earthquake activity in the study area, the depth variation of the b-value is also examined. The velocity structure is generally heterogeneous with both low and high velocities at upper crustal depths. Along the East Anatolian Fault Zone and its environs, low-velocity anomalies are charted. Also, small b-values (<1.0) are estimated in the region encompassing the KMES, especially at upper crustal depths. The KMES source zone is characterized by low b-value, low to average Vp, low Vs, and average/high Vp/Vs ratios. Hit count rates and the resolution test show that the mapped velocity anomalies are robust down to a depth of 45 km. Therefore, the moderate/high Vp/Vs and small b-values at the upper and middle crustal depths along the EAFZ may give constraints on the next earthquake hazards of the study region. The present findings provide deeper insight into the physical properties and the seismogenic potential of the crustal zones in proximity to the active fault segments of the Anatolian Plateau and the northwestern part of Arabia.
- MakaleYalnız künye2026Spatio-Temporal Distributions of Seismicity, Stress Evolution, and Tectonomagmatic Signatures of the 2025 Sındırgı Earthquake Swarm, Western Anatolia, Türkiye
Büyüksaraç, Aydin; Senkaya, Mustafa; Alkan, Hamdi; Bektas, Ozcan; Öztürk, Serkan; Pirti, Atinc; Yücel, Mehmet Ali
The Simav Fault Zone (SFZ) in Western Anatolia remains one of the most active tectonic regions in Turkey, and the 2025 S & imath;nd & imath;rg & imath; earthquake swarm has renewed concern regarding evolving seismic hazard. This study analyzes the swarm on the S & imath;nd & imath;rg & imath; Segment using Coulomb stress modelling, spatial distributions of b- and p-value, gravity and magnetic anomalies, geothermal data, and GNSS observations. Coulomb stress calculations show that the M-W = 6.1 and M-W = 6.0 mainshocks produced stress increases of similar to 0.1 bar that effectively loaded adjacent segments of the SFZ, D & uuml;vertepe Fault Zone (DFZ), and Gelenbe Fault Zone (GFZ), guiding the east-southeast and northward migration of aftershocks. Spatial statistics indicate a b-value ranging from 0.6 to 1.3 and a p-value between 0.3 and 1.0. The lower b-values (< 1.0) and p-values (< 0.5) mark high-stress regions near the mainshock, and higher values characterize more stable zones. Gravity anomalies delineate a dense volcanic-ophiolitic body in the southwest and a caldera-like depression south of the SFZ, while magnetic anomalies highlight the structural continuation and interaction of the SFZ with the GFZ. GNSS stations recorded centimetre-to millimetre-scale motions: BAL1 moved similar to 1.34 cm horizontally with minor uplift, DEI1 experienced similar to 1.12 cm displacement with small vertical fluctuations, and KIKA shifted similar to 0.85 cm southwestward with largely stable elevation. Together, these results show that the 2025 swarm was controlled by stress transfer within a mechanically heterogeneous tectonomagmatic system. The identified stress-enhanced corridors along the SFZ and DFZ may act as future nucleation zones, emphasizing the need for sustained monitoring of this evolving fault network.
- MakaleAçık Erişim2025Spatial and temporal analysis of seismicity and seismotectonic parameters in Albania region
Ormeni, Rrapo; Öztürk, Serkan; Silo, Erald; Bozo, Rrezart; Hoxha, Ismail; Mucaj, Dionald
A comprehensive analysis of b-value for the Albanian earthquakes was conducted using the instrumental earthquake catalogue of Albanian region. A total of 38,816 seismic events with magnitudes ML> 0.1 on the Richter scale were utilized. Statistical characteristics of the seismicity were examined based on b-value, as defined by the Gutenberg-Richter law. Considering the magnitude completeness (Mc-value) as 2.7, b-value was estimated as 1.09 ± 0.08 and it indicates a normal stress regime in the region. The Mc-value varies from 1.5 to 3.4, and spatial distribution of b-value ranges from 0.79 to 1.16. Higher b-values (> 1.0) were detected in the southernmost part of Albania, whereas lower b-values (< 1.0) were found in the western part, particularly within the Adriatic-Ionian fault zone and the Lushnje-Elbasan-Dibër transversal fault zone, as well as in the south-eastern Leskovik-Erseka-Korça fault zone. Regions with lower b-values correspond to areas with larger-magnitude events, while higher b-values are associated with smaller earthquakes. These findings suggest that b-values across Albania generally round 1.0, with lower values indicating moderate stress accumulation in the western region and within two other active seismic belts. The b-values less than 1.0 may signal areas of increased seismic potential. The occurrence probability of earthquakes across varying magnitudes was found to be very high (99%-100%) for seismic events with ML between 0.5 and 4.5, and lower (less than 95%) for events with ML > 5.5; it varied from 1% to 60% for events with larger ML > 6.0 for different Tr values. Recurrence periods for smaller magnitudes are relatively short (less than 1 year for magnitudes from 1.0 to 4.2), whereas for larger magnitudes (5.0 to 6.0), recurrence periods are longer, about 100 years. The Albanian region is characterized by a complex geological setting and significant seismic activity, and, thus, it can be stated that these types of analyses may be important in terms of seismotectonic evaluation and seismic hazard.
- MakaleAçık Erişim2025September 25, 2024 Yumrukaya-Tatvan (Bitlis, Türkiye) earthquake and a seismo-tectonic evaluation of its impact on the earthquake hazard in the region; [25 Eylül 2024 Yumrukaya-Tatvan (Bitlis, Türkiye) depremi ve bölgedeki deprem tehlikesine etkisi üzerine sismo-tektonik bir değerlendirme]
Öztürk, Serkan; Alkan, Hamdi
The current and future earthquake hazard in and around Bitlis were tired to reveal by utilizing the September 25, 2024, Yumrukaya-Tatvan earthquake (Mw=4.5) and its aftershocks, b-value and Z-value distributions, occurrence probabilities and recurrence periods of earthquakes and variations in Coulomb stress within the scope of this study. Also, it was tried to determine which fault systems in the study area is related to the Yumrukaya-Tatvan mainshock, characterized by strike-slip faulting. b-value in G-R relation was computed as 0.84∓0.06 and small b-values (<1.0) were imaged in the north-northwest-southeast directions throughout the South East Anatolian Thrust Zone and Muş Fault Zone, and west of Lake Van. At the beginning of 2025, significant seismic quiescence was observed near the Muş Fault Zone and the south and southeast of the South East Anatolian Thrust Zone. Recurrence periods for the events with the magnitudes of Mw=5.0, 5.5 and 6.2 were computed as ~10, ~26 and ~100 years, respectively. Additionally, occurrence probabilities of earthquakes with these magnitudes in the intermediate-term (~10 years) were calculated as ~64%, ~32% and ~10%, respectively. Positive Coulomb stress changes carry out a movement from the Kavakbaşı Fault zone in the west and the Beğendik segment in the east toward the South East Anatolian Thrust Zone in the east-southeast. In this region, there is no active fault/fault system according to the General Directorate of Mineral Research and Exploration. Thus, these findings are significant clues showing that multiple parameter seismo-tectonic analyses are important in determining the earthquake hazard for the September 25, 2024 earthquake, and that regions with small b-values and seismic quiescence and regions with positive Coulomb stress changes may indicate current hazard and possible earthquake zones in the future.
- MakaleYayıncıda açık erişim2025Statistical and seismotectonic analyses of the Marmara region under existing stress regime in the west of the NAFZ
Alkan, Hamdi; Öztürk, Serkan; Bektaş, Özcan; Büyüksaraç, Aydın
The Marmara Region is an active tectonic region in northwestern Türkiye, which comprises some important strike-slip active fault mechanisms and important tectonic units, located near the western part of the North Anatolian Fault Zone. In the historical and instrumental period, the Marmara Region experienced large/devastating earthquakes. Considering this continuous activity, in this study, we investigate the tectonic structure and performed future seismic hazard estimation of the region based on some seismotectonic parameters. For this evaluation, we plot the Coulomb stress change maps of 1912 Mürefte-Şarköy, 1953 Yenice-Gönen and 1999 İzmit mainshocks with the earthquakes (MW ≥ 4.5) that occurred in the study region after 2003. For the estimation of b-value, occurrence probabilities and return periods of earthquakes, we used a homogenous local seismicity catalogue consisting of 119.029 events for the period between 1912 and 2023. In the findings of this study, the lower b-values and increasing Coulomb stress changes which are trigger stress failure compatible are observed in the west and northwest of the Marmara Sea. In contrast, the higher/moderate b-values and decreasing Coulomb stress values are observed in the east and southeast of the Marmara Sea. The results of probability assessments show that an earthquake with Mw = 6.5 may occur with a probability of 98% in the west of the Marmara Sea after 2025. As a remarkable fact, a comprehensive assessment of these types of variables will supply important findings for earthquake hazard and potential in the study region.
- MakaleYalnız künye2025A Comprehensive Assessment for the Aftershock Sequence of August 11, 2012 Varzaghan-Ahar Doublet Mainshocks, NW Iran
Öztürk, Serkan; Yaghmaei-Sabegh, Saman
In this study, an evaluation of regional, temporal and magnitude properties of the August 11, 2012 Varzaghan-Ahar aftershock sequence was performed based on the different variables such as the Gutenberg-Richter b-value, the Modified Omori p-value, fractal dimension Dc-value and the maximum aftershock magnitude Mamax value which commonly used to describe aftershock behaviors. b-value was computed as 0.73 ± 0.03 for the study area where catalog has a completeness magnitude Mc = 2.0. This b-value is relatively small from typical b≈1 and it can be due to the abundance of aftershocks larger than Mw = 4 in the region. Structural heterogeneity of the seismic source along with the compressive stress situation of the aftershock area could be another reason for this finding as well. p-value was estimated as 1.00 ± 0.03 where c-value took 0.342 ± 0.106 according to the analysis which shows that the number of aftershocks of the Varzaghan-Ahar mainshock shows a relatively fast decrease. Dc-value was computed as 1.84 ± 0.07. This large value indicates homogeneously distributed aftershocks and more clustering in smaller areas or larger scales. As a result, the smallest b-values (< 0.7) and Mamax values larger than 5.0 were obtained around the mainshock. In addition, the biggest p-values (> 1.2) were found in and around the mainshock including Varzaghan. The areas having the biggest p-value and the lowest b-value have great coseismic deformation and stress, respectively. Hence, we can say that coseismic deformation and stress distributions are very effective on the b- and p-value changes. Thus, particular attention on assessing the aftershock hazard may be directed on the understanding of these spatio-temporal aftershock variables.
- MakaleAçık Erişim2025Analyzing the October 16, 2024 MW 5.9 Kale (Malatya) earthquake in relation to the February 2023 Kahramanmaraş earthquake sequence and local tectonic dynamics
Senkaya, Mustafa; Alkan, Hamdi; Öztürk, Serkan; Büyüksaraç, Aydın
The 6 February 2023 Mw 7.7–7.6 Kahramanmaraş earthquake sequence has significantly impacted the East Anatolian Fault zone, including the city of Malatya and its immediate surroundings. In addition to the aftershocks of February 2023, the Mw 5.9 Kale earthquake that occurred on October 16, 2024, further underscores the ongoing seismic activity in the region. This study analyzes the distribution of b-values derived from a comprehensive dataset comprising 14,549 earthquakes and the Coulomb stress variations associated with the aftershocks of the February 2023 sequence and the Kale earthquake. The primary objective of this analysis is to enhance the understanding of the tectonic setting that contributed to the occurrence of the Kale earthquake. The findings indicate that the low b-values and stress transfer through the Pütürge segment toward the unnamed fault near Kale are significant contributing factors to the occurrence of the Kale earthquake. Additionally, positive stress variations from Doğanşehir to Malatya’s city center suggest a potential fault oriented toward the city center that may increase the current earthquake hazard. Furthermore, the distribution of seismic events around Malatya suggests a possible barrier supported by previous magnetic data analysis between Malatya and Kale. Lastly, the observed stress variations for the Kale earthquake indicate the likelihood of upcoming seismic events in both the northeast and southwest directions of the Kale.
- MakaleAçık Erişim2024Gümüşhane ilinde deprem ivme ve manyetik alan istasyonlarının kurulumu ve işletilmesi
Öztürk, Serkan; Maden, Nafiz; Beker, Yasemin; Sari, Mahmut; Pehlivan, Levent
Bu çalışmada, Kuzey Anadolu Fay Zonu (KAFZ) üzerinde meydana gelen bir depremden Gümüşhane ilinin etkilenme derecesini belirlemek üzere deprem ivme kayıt cihazlarının yerleştirilmesi ve Güneşte meydana gelen fırtınalar nedeniyle yer Manyetik alanındaki değişimleri gözlemlemek amacıyla 3 bileşen Flux-Gate manyetometrenin kurulumu amaçlanmıştır. Deprem ivme kayıt cihazlarının (3 adet); Gümüşhane ili için önem taşıyan Karaca Mağarası ve Kürtün hidroelektrik santrali ile KAFZ’na yakınlığından dolayı Şiran MYO’na kurulması uygun görülmüştür. Flux-gate Manyetometresi ise Gümüşhane Merkez ilçede kurulmuştur. KAFZ üzerinde meydana gelen bir depremden Kelkit, Şiran ve Köse ilçeleri daha çok etkilenirken Torul ve Kürtün ilçeleri daha az etkilenmektedir. Gümüşhane’nin 17 km kuzeybatısında yer alan Karaca Mağarası bölgemizin önemli turizm merkezlerinden birisidir. Kürtün ilçesinde, Harşit nehri üzerinde kurulu olan Kürtün Hidroelektrik santrali enerji amaçlı olarak hizmet vermesi yanında baraj gölü üzerinde balık üretimine ve su sporları yapılmasına imkân sunmaktadır. Güneşte aniden gelişen çok şiddetli patlamalar dünyaya ulaştıklarında elektrik ve iletişim hatlarını kesilebilmekte, radyo haberleşmesinde bozulmalara ve radyasyona sebep olmaktadır. Gümüşhane kurşun, çinko, bakır, altın ve gümüş gibi değerli metaller açısından oldukça yüksek bir potansiyele sahiptir. Bu tür maden yataklarının belirlenmesinde Jeofizik yöntemlerden bir tanesi olan Manyetik yöntem oldukça başarılı bir şekilde kullanılmaktadır. Bu yöntemde arazide ölçü alınırken yer manyetik alanının sürekli kaydedilmesine hizmet edecektir.
- MakaleAçık Erişim2024Hakkari ve Civarının (Güneydoğu Anadolu, Türkiye) Güncel Deprem Potansiyeli: Bölge-Zaman-Magnitüd Analizleri
Öztürk, Serkan; Alkan, Hamdi
Hakkari (Türkiye), depremsellik ve tektonizma olarak Güneydoğu Anadolu Bölgesinin en aktif illerinden bir tanesidir. Aletsel ve tarihsel dönemde, Hakkari ili ve civarında bulunan bu fay ve fay zonları birçok yıkıcı/hasar verici deprem üretmiştir. Son yıllarda Aralık 2023 (Mw=4.7) ve Şubat 2024’de (Mw=4.3) meydana gelen depremler, bu bölgedeki güncel depremselliğin önemli göstergelerindendir. Analizlerden elde edilen bulgulara göre, bölgede ortalama b-değeri 0.880.09 olup en düşük b-değerleri Yüksekova-Şemdinli Fay Zonu civarında gözlenmiştir. Buna ek olarak, pozitif Coulomb gerilme değişimleri Hakkari ili ve civarında KB-GD ve KD-GB yönlü olarak ortaya çıkmıştır. Diğer taraftan, seçilen bölge için Mw=5.0 büyüklüğündeki bir depremin tekrarlama zamanı ~16 yıldır. Ayrıca, Mw=5.0 büyüklüğündeki bir depremin 10, 16 ve 20 yılda oluşma olasılıkları ise sırasıyla ~%45, ~%62 ve ~%69 olarak hesaplanmıştır. Sonuç olarak, bu çalışmada hesaplanan sismotektonik parametrelerin birlikte değerlendirilmesi ile Hakkari ili ve civarının güncel sismik tehlike potansiyeli ortaya çıkarılmıştır.
- MakaleAçık Erişim2024An evaluation of the earthquake potential with seismic and tectonic variables for the West Anatolian region of Türkiye
Öztürk, Serkan; Alkan, Hamdi
In the present study, an evaluation of the region-time-magnitude behaviours of the earthquake occurrences in the West Anatolian Region (WAR), Türkiye, is carried out using the statistical and seis-motectonic parameters such as the b-value of Gutenberg-Richter relation, occurrence probabilities, and return periods of earthquakes. We also have mapped the Coulomb stress changes to observe the current and future earthquake hazard. In recent years, several large earthquakes such as the 1919 Soma (Mw = 6.7) and the 2022 and 2024 Aegean Sea (Mw = 5.3 and Mw = 5.1) revealed earthquake potential in the WAR. Coulomb stress analyses of 41 local events with mostly normal fault mechanisms have shown that posi-tive lobes (> 0.0 in bars) are mainly confined in the crust and uppermost mantle depths around Samos, Kos, and south of Lesvos. The smaller b-values (< 1.0) are observed in the same regions. On the contrary, we have observed a higher b-value from the offshore to onshore, south to north-trending direction, and negative scattered stress lobes (< 0.0 in bars) in slightly NW–SE oriented. The relationship between an increased b-value and negative stress change may indicate a similar seismicity for the region. In addition, we have analyzed the occurrence probabilities and return periods of the earthquakes, which showed us that Mw = 6.0 may occur at 75% in the intermediate term with an estimation of ~7 years. Our results reflect that these types of multiple-parameter assessments are important to define regional seismicity, seismic, tectonic, and statistical behaviours. Consequently, the areas with reductions in b-values and increments in stress imply the possible seismic hazard in the intermediate/long term.
- MakaleAçık Erişim2023Analysıs of coulomb stress transfer and earthquake hazard ın the çaldıran fault zone and ıts adjacent regıon
Öztürk, Serkan; Akkaya, İsmail; Alkan, Hamdi
Çaldıran fault zone (CFZ) are significant seismically active zone that generated many destructive earthquakes. In this fault system, the last of these major earthquakes occurred on 1976 (Ms = 7.3). Therefore, based on the seismotectonic b-value, earthquake probability, recurrence times and Coulomb stress changes, we investigate the future earthquake potential and positive/negative stress changes in this fault zone. The events with a magnitude greater than 3.6 are used to investigate stress transfer direction regarding the seismotectonic parameters. The results indicate that the regions having smaller b-values are obtained along with the SE of CFZ, whilst higher b-values are calculated around the east of Lake Van. On the other hand, the northeast of CFZ represents current stress accumulation. Similarly, the Coulomb stress variations of 1976 earthquake show that stress accumulated at different depths in the northwest of this fault system. In addition, considering the long-term slip rates and horizontal offset in previous studies, the recurrence time of earthquakes has approximately 302 years for a magnitude greater than 6.0. Finally, these comprehensive analyses explain the implications of seismic hazard evaluation and forecasting of possible next earthquake occurrences in this region.
- MakaleAçık Erişim2023Correlations between seismic b-value and heat flow density in Vlora-Lushnja-Elbasani-Dibra Fault Zone in Elbasani area, central Albania
Ormeni, Rrapo; Hasimi, Albana; Öztürk, Serkan; Çomo, Ervin
In this study, the correlations between the heat flow density and seismotectonic b-value in the El-basani area of Albania were investigated to understand the how low-velocity layers underneath the Elbasani area in central Albania struggling the large-scale Vlora-Lushnja-Elbasani-Dibra Fault Zone affect the heat flow data. For this purpose, the heat flow and regional distribution of b-value were imaged for different locations and depths. To achieve the analysis, the Albanian Seismological Catalogue for the period between 1 July 1968 and 26 December 2022, including 1830 earthquakes with a local magnitude of 0.5 ≤ Ml ≤ 5.2 that occurred at the depths below 70 kilometres, was considered. The b-value was calculated as 1.03 ± 0.06 by considering the magnitude of the completeness value as Mc-value = 2.6. This result shows that the b-value of earthquake distribution in the Vlora-Lushnja-Elbasani-Dibra (VLED) fault zone is well represented by the Gutenberg and Richter (G-R) scaling law with the b-value close to 1.0. The regional variations of the b-value show that b-values smaller than 0.9 were observed in the western and south-western parts of the Llinxha-Kozan thermal water belt. The depth distribution of the b-value indicates that there exists a sharp decrease in the b-values from 1.15 to 0.7 in the depths varying from 5 to 20 km. The highest heat flow values were observed on the Dumrea diapiric dome and in the central part of the Elbasani area. Thus, our analysis indicates significant and robust correlations between the geothermal and earthquake distribution. The discontinuity of Moho interface is deep in the regions where high b-values were observed. Low b-values are found at the depths ranging from 20–25 km and 35–40 km in the Dumrea evaporite massif area. We have evidence that high b-values and large heat flow values are related to the low seismic velocity layers underneath the Elbasani area. The low-velocity zone (LVZ) in Albania occurs in the Earth’s crust and in the upper mantle. It is characterized by an unusu-ally low seismic shear wave velocity compared to the surrounding depth intervals. It is well known that the low-velocity layers in the Elbasani area are determined in the upper crust, at shallow depths of 2–4 km, and in the middle crust at a 10–14 km depth. Hence, it is suggested that the Moho interface in the eastern part of the Elbasani area is relatively deep (45 km) compared to the western part of Albania (35 km), and the magnitude of earthquakes is smaller where the high heat flow values were observed.
- MakaleAçık Erişim2023Multiple parameter analysis for assessing and forecasting earthquake hazards in the Lake Van region, Turkey
Öztürk, Serkan; Alkan, Hamdi
A detailed spatial-temporal analysis of the seismic activity in and around the Lake Van region was performed using several seismotectonic parameters such as b-value, Z-value, relative intensity (RI), pattern informatics (PI), and Coulomb stress changes. Correlations between these parameters were analyzed to esti-mate and forecast potential seismic hazards in the Lake Van region. Particular attention was paid to the parts of the study region that exhibited smaller b-values, higher Z-values, and high-stress changes at the beginning of 2022 and to the locations of earthquake hotspots determined from the composite earthquake forecast map for 2022–2032, i.e., Muradiye, Çaldıran, Özalp, Erçek, Van city center and Gevaş covering the faults of Çaldıran, Yeniköşk, Erciş, Malazgirt and the fault zones of Saray and Van. To provide more accurate interpretations regarding potential earthquake occurrences in the near future, the seismotectonic parameters analyzed in the scope of this study were compared with the corresponding seismological, geological, geodetical, and geochemical variables reported in the literature. This comparison showed that, firstly, our results are consistent with those reported in previous studies, and, secondly, all these variables should be interpreted in combination to correctly assess strong earthquake hazards. Furthermore, this type of multiple-parameter analysis may be important for the description of seismic, tectonic, and structural characteristics of the nature of the crust. Our findings show that almost all seismotectonic parameters indicative of anomaly regions, i.e., lower b-values, higher Z-values, high-stress distribution, and hotspots, were recorded in the same parts of the study region. Thus, the anomaly regions detected at the beginning of 2019 and between 2022 and 2032 may be considered to be potential zones of future great earthquakes. To summarize, the correlations among these variables may provide accurate information for assessing and forecasting earthquake hazards in this region.
- BildiriYalnız künye2023REGION-TIME-MAGNITUDE ANALYSES OF EARTHQAUKE ACTIVITY IN THE ELBASANI GEOTERMAL ZONE, ALBANIA
Ormeni, Rrapo; Öztürk, Serkan; Hasimi, Albana; Silo, Erald; Como, Elvin; Trofymchuk, O.; Rivza, B.
A detailed analysis of the b-value within the Elbasani fault zone, Albania, were studied. From instrumental seismicity in this area have been located 1830 seismic events, with magnitude Ml>0.5 Richter. In the zone of Elbasani, hot mineral water (thermal waters) spot out from natural springs which have been known since the 19th century. The statistical properties of seismicity are analysed by using b-value known as Gutenberg-Richter law. The magnitude of completeness (Mc) value is determined as 2.6, and the bvalue is calculated as 1.03 ± 0.06, and it is determined that the region has a normal stress level. It is seen that the Mc-value varies from 1.6 to 2.9, the b-value changes between 0.9 and 1.3. The regions with the large b-values (> 1.0) are estimated in the eastern parts of the of Elbasani zone. However, the regions with the low b-values (< 1.0) are observed in the north, west and southwest of Elbasani zone. The regions with the small b-values correspond to great-magnitude events, whereas the other large values are related to smallmagnitude earthquakes. These results reveal that b-values for all regions are well represented by a b-value typically close to 1.0. There are clear decreasing trends in temporal changes of b-values before the occurrences of some strong main shocks. The lower b-value indicate that there is still moderate stress accumulation in the southwest area of the Llinxha-Kozan thermal water belt. The b-values smaller than 1.0 indicate potential future earthquake area. Following the strong events, there are remarkable decreases in b-value as a function of time. Changes in b-value with time varies in a large band between 0.6 and 1.4. Probabilities of earthquake activity in different magnitude sizes show comparatively great values changing from 50-100 % for earthquakes of 0.5 ≤ Ml≤ 4.5 and the values relatively lower than 90 % for the earthquakes of 5.0 ≤ Ml. The Elbasani zone has a complex geological structure with a significant number of geothermal water resources and some features of seismicity.
- MakaleAçık Erişim2023An evaluation of the characteristic aftershock parameters following the 24 January 2020 MW = 6.8 Elazığ-Sivrice (Türkiye) earthquake
Öztürk, Serkan
A comprehensive evaluation of region-time-magnitude behaviours of aftershocks following the 24 January 2020 (Mw = 6.8) Elazığ-Sivrice (Türkiye) earthquake was achieved by using the characteristic parameters such as b-value, p-value, Dc-value and Mamax value of aftershock occurrences. The b-value was calculated as 0.82 ± 0.02 by considering the magnitude of the completeness value as Mcomp = 1.9, and it is relatively small compared to typical b ≈ 1 for the magnitude-frequency relationship of aftershocks. This low b-value may also be caused by the abundance of aftershocks with ML ≥ 4.0. The p-value was computed as 0.80 ± 0.02 with c-value = 0.279 ± 0.098 and is smaller than the global value of p ≈ 1. This low p-value may be due to a relatively slow decay rate of aftershock activity, and the modified Omori model seems appropriate for the estimation of decay parameters. The Dc-value was estimated as 1.87 ± 0.07. This large value shows that aftershocks are homogeneously distributed and more clustered at larger scales/in smaller areas. The temporal variation of b-value indicates that decreases in b-value may result from the gradual increase in the effective stress following the larger aftershocks. The lowest b-values and Mamax values greater than 5.0 were observed in the north, south and southwest parts of the mainshock including Pütürge and Erkenek segments. These results show that there is an apparent relation between the smallest b-values and the largest Mamax values. The largest p-values were estimated in and around the main shock including Pütürge segment. The regions with the smallest b-value and the largest p-value have high stress and coseismic deformation, respectively. Stress variations and coseismic deformation are extremely effective on the changes of b-and p-values. As a remarkable result, aftershock hazard following the mainshock may be considered extremely related to aftershock parameters, and detailed analyses of the region-time-magnitude characteristics of aftershocks are recommended for a preliminary evaluation following the mainshock.
- MakaleYalnız künye2023Seismic Hazard Implications in and Around the Yedisu Seismic Gap (Eastern Türkiye) Based on Coulomb Stress Changes, b-Values, and S-wave Velocity
Alkan, Hamdi; Öztürk, Serkan; Akkaya, İsmail
The Yedisu Seismic Gap is one of the most important seismic gaps throughout the North Anatolian Fault Zone since it has not produced destructive earthquakes for a long time. To analyze the characteristics of future seismic hazards, the interrelationships between seismotectonic b-values, Coulomb stress changes, and S-wave velocity models of crust are presented in and around the Yedisu Seismic Gap located northwest of the Karlıova Triple Junction. For this purpose, the most up-to-date earthquake catalog and the focal mechanism solutions of recent earthquakes are used to image the different depth intervals. Results show that the relatively positive stresses are accumulating along the Varto Fault Zone and Kargapazarı and Yedisu Segments between 5 and 15 km depth intervals. At the same time, the lower b-values between 0.6 and 1.0 are found in the same segments. However, in the volcanic regions around the Karlıova Triple Junction, the low S-wave velocity zones may be related to high b-values, negative stress changes, and volcanic structures. The region between the Turnadağ volcano and the Varto caldera shows scattered stress and b-value changes in the upper crust. Moreover, the probability of earthquakes for Mw = 6.0, 7.0, and 7.7 in the intermediate term (10 years) is estimated as ~ 65%, ~ 17%, and ~ 5%, respectively. Recurrence of earthquakes with Mw = 6.0, 7.0, and 7.7 are calculated as ~ 10, ~ 55, and ~ 187 years, respectively. Consequently, the regions characterized by low strong b-values and positive stress loading reveal high earthquake hazard potential on the whole in the next decade.
- MakaleAçık Erişim2023Understanding university students WHO do not want to volunteer in disasters: A qualitative study from Türkiye
Demirbilek, Ömer; Öztürk, Serkan
A functional and sufficient volunteer community is needed to reduce the damage of disasters and to have a rapid response and recovery process. Most of the volunteering studies in disasters in the literature focus on the positive side of the volunteering process, but there are many negative points that prevent individuals from volunteering in disasters. In this research, it is aimed to discover why university students, who are one of the most valuable groups in volunteering in disasters, do not volunteer in disasters. The research was conducted with a phenomenological design. Maximum variation and criterion sampling were used to decide the study group. The study group consists of thirteen university students with distinctive characteristics. The interview method was used as the data collection technique, and the semi-structured interview form developed by the researchers was used as the data collection tool. Thematic analysis was conducted with the MAXQDA 2020 qualitative analysis program on the obtained data. As a result of the data analysis, seven themes appeared, consisting of İnformation, Economy, Interpersonal Bonds, Uncertainties, Individual Characteristics, Perceptions of Volunteering, Promotion and Advertising Activities. Finding the negative aspects of volunteering that distracts young people from volunteering will be one of the best preparations for future disasters.