Authors: EDA ESMA EYÜBAGİL, HALİL İBRAHİM SOLAK, UMRE SELİN KAVAK, İBRAHİM TİRYAKİOĞLU, HASAN SÖZBİLİR, BAHADIR AKTUĞ, ÇAĞLAR ÖZKAYMAK
Abstract: Herein, a combined analysis of Global Navigation Satellite System-derived strain rate maps, in accordance with recent seismicity, was presented to reveal that the N-S extension is accommodated primarily by strike-slip faulting of the İzmir-Balıkesir Transfer Zone (İBTZ), where a counter clockwise rotation (~25-100°/Myr) along the vertical axis is dominant. The results indicated that strike-slip segments within the İBTZ show variable transport sense and amount of slip along them, and they connect by hard linkage relay ramps with the dip to oblique slip normal faults. According to the strain map, the Karaburun Peninsula has the largest strain rates, at 137 nano strain (nstrain)/yr extension (NE-SW) and 126 nstrain/yr (NW-SE) compression. To the south, the largest strain areas begin to shrink where the NW-trending sinistral Riedel Fault is located. The smallest strains in the region were measured on the NE-trending Tuzla Fault, compatible with the right lateral component. Based on this, the northern part of the Karaburun Peninsula has the shortest recurrence period in the region. The geodetic earthquake recurrence periods throughout the region comprise 800 yr for magnitudes 7 and above and 70 year for magnitudes between 6 and 7. The period was calculated as 30 years for M > 5.5 (with 99% probability) and 100 years for M > 6 (with 95% probability). These were consistent with the geodetic earthquake recurrence periods (25-30 years for M > 5.5 and 80-100 years for M > 6). This result showed that the seismic hazard sources in the region have increased the earthquake risk, which may cause loss of life and property in the near future.
Keywords: İzmir-Balıkesir Transfer Zone, Global Navigation Satellite System, slip rate, geodetic recurrence interval, strike-slip tectonics
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