Acta Geophysica, vol.71, no.1, pp.129-146, 2023 (SCI-Expanded)
© 2022, The Author(s) under exclusive licence to Institute of Geophysics, Polish Academy of Sciences & Polish Academy of Sciences.The city of Trabzon has no site classification map or site-specific analyses representing the assessment earthquake hazard so far, although Trabzon had been influenced and damaged due to earthquakes that occurred particularly in the North Anatolian Fault zone both in the recent and distant past. This paper presents the site classification and analyzes the site-specific pseudo-spectral acceleration (PSA) for densely populated areas of Trabzon. The coastline and the east and west edges of the city demonstrate minimum Vs30 in the overall study area from 175 to 396 m/s, respectively, which falls CD to DE class in NEHRP, and ZC to ZE in TBDY. The Vs30 of the remaining areas vary between 347 and 851 m/s, representing CD to BC in NEHRP and ZD to ZB in Turkish Building Regulation. The wide range of Vs30 is mostly due to the depth of the volcanic main rock, altered and agglomerated settings of dominant formation. The estimated PSA curves along the coast side of Trabzon including the lowest Vs30 demonstrate significantly greater spectral acceleration values than the design spectrum, particularly in TA–TB range that was used for almost whole constructions in the study area. Also, PSAs of the neighborhoods mostly classified as ZC in TDBY indicate overlapping with design spectrums and peak values are pretty close to limits. As a result, the proposed paper demonstrates that the earthquake hazard should not be underestimated, in particular considering the high possibility of well-known frequent ruptures on the east side of the North Anatolian Fault.