Fling amplitude inventory of near-fault strong motion recordings in Turkiye

Abstract

The fling step, a significant near-field effect, has an adverse impact on long-period engineering structures. Despite early recognition by pioneers, identifying and processing the ground motions containing the fling step remains challenging due to conventional data filtering methods that ignore low-frequency components. This study investigates the recovery of the fling step from near fault records and by modifying and/or adding processing steps to previous methods, proposes a robust processing scheme for strong ground motion recordings in capturing fling amplitude. The proposed scheme’s capability is verified through GNSS-derived displacements from global and Turkiye earthquakes. Subsequently, the method is applied to strong motion recording in the Turkish dataset (Mw ≥ 6 shallow crust earthquakes recorded at R_JB≤50 km), resulting in a comprehensive inventory of fling amplitudes across multiple motion components. This inventory serves both engineering and earth sciences research by facilitating the evaluation of existing predictive models. In addition, a Türkiye-specific performance evaluation of existing predictive models is conducted using the presented database. Lastly, a refined fling amplitude prediction model, based on conformity with the presented fling inventory, is proposed. This work addresses critical gaps in strong ground motion analyses, promoting improved seismic resilience through accurate characterization of near-fault effects.