On the Resolution of H/v Measurements to Determine Sediment Thickness, a Case Study Across a Normal Fault in the Lower Rhine Embayment, Germany

Investigation of local site responses at the Bodrum Peninsula (Southwest of Turkey) using the mainshock and aftershocks of the 20 July 2017 Mw6.6 Bodrum-Kos earthquake

“…This relationship has became a common practice since their work in the context of seismic hazard assessment [Chia and Lau, 2017;Tun et al, 2016]. Numerous authors, working along similar lines, have developped such relationships which provide a practical means of sediment thickness estimation at different soils [Ibs-von Seht and Wohlenberg, 1999;Delgado et al, 2000a,b;Parolai et al, 2002;Hinzen et al, 2004;Kanli et al, 2008;Birgoren et al, 2009;Ozalaybey et al, 2011;Tun et al, 2016;Chia and Lau, 2017]. Empirical functions established by above scientists are given in Table 3 and were plotted in Figure 7.…”

“…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]. Recent studies, based on relationship between the main peak frequency (fr in Hz) of a given soil, its thickness (h in meter) and the average shear velocity (Vs in m/s), have demonstrated the possibility to establish a direct functional relationship between the frequency of resonance and depth to bedrock, without knowing shear velocity [Ibs-von Seht and Wohlenberg, 1999;Kanli et al, 2008;Tun et al, 2016].…”

“…However, the shaking at one site can easily be much stronger than at another site, even when their epicentral distances are the same. There is a general agreement among scientists and researchers that local geology have significant effect on seismic motions [Hinzen et al, 2004;Pancha et al, 2015;Safak, 2001]. Therefore, investigation of this effect, estimation of the local response of a site is an important aspect in the assessment of local seismic hazard [Bour et al, 1998].…”

Site-specific response spectra from the combination of microzonation with probabilistic seismic hazard assessment—An example for the Cologne (Germany) area

“…They consist mainly of gravel, sand and clays. The thickness of the sedimentary layer generally increases from 0 m northeast of Cologne, where the Devonian basement rocks outcrop in the Bergisches Land, to more than 1000 m west of the Erft fault system [14,16,17]. The crosssection is shown in Fig.…”

“…Other relationships between the fundamental resonance frequency of the site and the thickness of the sedimentary cover have been derived for the area, e.g. [17,20]. The sedimentary cover thickness below these sites ranges from about 20 m in the NE to more than 1000 m in the west [14].…”