Abstract
Bodrum Peninsula located in the province of Mugla is situated in southwest Turkey. T he peninsula is one of the most populated touristic centers of the southwest coast of Turkey, near the Aegean Sea. However, t his region is surrounded by numerous active seismic entities. All of those systems have capability of producing large magnitude earthquakes and pose a great threat to settlements in and around of this region. Considering the high seismic risk and population of the peninsula, a strong ground motion monitoring system was deployed in June 2015. So far the network recorded many earthquakes in different magnitude and distances. In this study, a dataset with 51 events with moment magnitudes from 4.0-6.6 occurred within 100 km epicentral distances were selected for site effect calculation. This dataset includes the mainshock and its significant aftershocks records of the Mw6.6 Bodrum-Kos earthquake (20 July 2017, 22:31 UTC) . Predominant frequencies and amplification values of shallow soil layers under the stations were estimated through Horizontal to Vertical Spectral Ratio and Standard Spectral Ratios. The results indicate that predominant frequencies change between 2.1 - 2.7 Hz for soft soils, where it is 4.8 Hz for the reference site B5, and relative amplifications are in the range of 1.0 to 6.6. Then, sediments thicknesses beneath the stations were empirically calculated by using p redominant frequencies . In addition, the damage distribution of the Bodrum-Kos earthquake was discussed with its relation to the estimated resonance frequencies and relative amplifications. O bservations regarding to the Mw6.6 earthquake have revealed that unreinforced masonry structures, in particular, old stone houses were damaged while there were generally no apparent structural damage at reinforced buildings.
Highlights
The most forceful shaking during earthquakes generally occurs near the rupturing fault, and its impact decreases with distance away from the fault
Damages or collapses were mostly occured at Yali district (Table 4) while its relative amplification value is low (Table 5). Taken together these findings suggest that no direct relationships exist between damage distribution in the Bodrum peninsula and the resonance frequencies & the relative amplifications
In the present study an attempt mainly has been made to calculate predominant frequencies and amplification values considering local site effects related to the Bodrum peninsula
Summary
The most forceful shaking during earthquakes generally occurs near the rupturing fault, and its impact decreases with distance away from the fault. The HVSR method generally provides reliable estimates of resonance frequency despite of its inadequacy in estimating amplification [Bard, 1999; Lermo and Chavez-Garcia, 1994], while SSR method is considered as the reliable method in determining the effects of local site conditions [Molnar and Cassidy, 2006; Yalcinkaya and Alptekin, 2005] Another important parameter for the site effects, in the context of seismic hazard assessment, is the thickness of a sediment fill in sedimentary areas [Hinzen et al, 2004]. A second goal is to decide to a suitable empirical relation from among proposed actual empirical relationships between resonance frequencies and thickness of sediments, especially for the soft layers under the stations deployed in the peninsula Another objective is to refer to the damage distribution of July 20, 2017 (Mw=6.6) Bodrum-Kos (Turkey-Greece) earthquake and look over its relation to resonance frequencies and relative amplifications.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
