An investigation of seismicity for western Anatolia

• Published in: Natural hazards (Dordrecht) 2008, Vol.44 (1), p.51-64
• Main Authors: Sayil, Nilgün, Osmanşahin, İlhan
• Format: Article
• Language: English
• Subjects: Civil Engineering; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Earthquakes; Earthquakes, seismology; Engineering and environment geology. Geothermics; Environmental Management; Exact sciences and technology; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hazards; Hydrogeology; Internal geophysics; Natural Hazards; Natural hazards: prediction, damages, etc; Original Paper; Plate tectonics; Seismology
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-007-9141-2

In order to investigate the seismicity of western Anatolia limited with the coordinates of 36°–40° N, 26°–32° E, Gutenberg–Richter magnitude–frequency relation, seismic risk and recurrence period have been computed. The data belonging to both the historical period before 1900 (I 0  ≥ 5.0 corresponding to M S  ≥ 4.4) and the instrumental period until the end of 2006 (M S  ≥ 4.0) has been used in the analysis. The study area has been divided into 13 sub-regions due to certain seismotectonic characteristics, plate tectonic models and geology of the region. All the computations have been performed for these sub-regions, separately. According to the results, a and b values in the computed magnitude–frequency relations are in the intervals 3.19±0.17 – 5.15±0.52 and 0.42±0.05 – 0.66±0.07, respectively. The highest b values have been determined for sub-regions 3 and 12 (Demirci-Gediz and Gökova Gulf-Muğla-Gölhisar). The lowest b values have also been determined for sub-regions 1 and 9 (Balıkesir and Bodrum-İstanköy). Finally, seismic risk and recurrence period computations from a and b values have shown as expected that sub-regions 1 and 9 which have the lowest b values and the highest risks and the shortest-recurrence periods.