Ground Motion Characterization for Vertical Ground Motions in Turkey—Part 2: Vertical Ground Motion Models and the Final Logic Tree

• Published in: Pure and applied geophysics 2020-05, Vol.177 (5), p.2105-2123
• Main Authors: Gülerce, Zeynep, Alipour, N. A., Sandikkaya, M. A.
• Format: Article
• Language: English
• Subjects: Datasets; Earth and Environmental Science; Earth Sciences; Geophysics/Geodesy; Ground motion; Logic; Scaling; Spectra; Vertical motion
• ISSN: 0033-4553; 1420-9136
• DOI: 10.1007/s00024-019-02353-7

The main objectives of this study are: (1) to choose the vertical ground motion models (GMMs) that are consistent with the magnitude, distance, depth, and site amplification scaling of the updated Turkish ground motion database, and (2) to combine the vertical GMMs with the V / H ratio models selected in the accompanying paper (Alipour et al. in Pure Appl Geophys 1–22, 2019) to provide the ground motion characterization logic tree for the vertical ground motion component in Turkey. Four global vertical GMMs [proposed by Bozorgnia and Campbell in Earthq Spectra 32(2):979–1004, 2016b; Stewart et al. in Earthq Spectra 32(2):1005–1031, 2016; Gülerce et al. in Earthq Spectra 33(2):499–528, 2017 using the NGA-West 2 database; and Çagnan et al. in Bull Earthq Eng 15(7):2617–2643, 2017 model based on the RESORCE database] are selected, and the model predictions are compared with the actual data in the updated Turkish ground motion dataset using the analysis of the residuals. Analysis results showed that the magnitude scaling of Çagnan et al. (2017) model and the depth scaling of the Bozorgnia and Campbell (2016b) model are inconsistent with the Turkish strong motion database. Additionally, small-magnitude (SM) scaling of Stewart et al. (2016) and Gülerce et al. (2017) GMMs should be modified for a better fit with the Turkish dataset. Trellis plots of SM-modified Stewart et al. (2016) and SM-modified Gülerce et al. (2017) vertical GMMs and selected V / H ratio models multiplied with NGA-West 2 and Turkey (TR)-adjusted horizontal NGA-West 1 models [Gülerce et al. in Earthq Spectra 32(1):75–100, 2016] are used to determine the logic tree weights for the proposed vertical ground motion characterization logic tree for Turkey.