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- MakaleYayıncıda açık erişim2025Scopus SJRQ2Statistical 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.
AtıfScopus12WoS8OpenAlex11İncele - MakaleYalnız künye2020Scopus SJRQ3A GENERAL OVERVIEW ON THE REGION-TIME BEHAVIORS OF THE RECENT EARTHQUAKE ACTIVITY IN THE MARMARA REGION OF TURKEY
Öztürk, Serkan; Gerdan, Serpil
The principal aim of this study is to make a general assessment of the regional and temporal behaviors of the seismicity in the Marmara region of Turkey. For this purpose, the well-known spatio-temporal tools such as Mc-value, b-value, Dc-value, Z-value, recurrence period and annual probability were evaluated. The data catalog is homogeneous for local magnitude, ML, and includes 18,662 events with 0.4≤ML≤5.7 between 2000 and 2020. Earthquake magnitudes change between 1.5 and 3.0 and hence, Mc-value was taken as 2.7. b-value was calculated as 1.14±0.07 and the earthquakes with small magnitude can be effective on this relatively large value. Dc-value was estimated as 1.57±0.03 with a scale invariance from 5.03 to 87.64 km. This moderate value means that distance between the epicenters approaches the diameter of cluster and, earthquake activity is more clustered in larger areas or at smaller scales. Time-magnitude estimations of annual probability and recurrence period indicate that the Marmara region has an intermediate/long terms hazard for the occurrence of strong/large earthquakes. Anomaly regions with low b-value and large Z-value observed at the beginning of 2019 can be considered as the most likely regions for strong/large earthquake occurrences in the next. As a remarkable fact, a correlation and combined interpretation of these seismotectonic parameters may supply a preliminary and essential perspective in the seismic hazard for strong/large earthquake occurrences in the Marmara region of Turkey in the intermediate/long terms.
AtıfScopus3WoS4İncele