Yazarlar

  • MakaleAçık Erişim2025Scopus SJRQ3
    Spatial 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.

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  • MakaleAçık Erişim2025Scopus SJRQ4
    September 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.

    AtıfScopus2OpenAlex2TR Dizin1
    ScopusTR Dizinİncele
  • MakaleYayıncıda açık erişim2025Scopus SJRQ2
    Statistical 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.

    AtıfScopus12WoS8OpenAlex11
    ScopusWeb of Scienceİncele
  • BildiriYalnız künye2023
    REGION-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.

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