Permanent Displacement Distribution From Strong Ground Motion Records of the 2023 Mw7.7 Earthquake.

One of the most damaging earthquake effects occurring in the vicinity of the fault trace is fling step, also known as permanent displacement. However, due to the fact that the standard filtering techniques eliminate the low frequency portions of the motion, the permanent displacements are not seen on the displacement time histories derived from the accelerogram records. Thus, fling step is neglected in many engineering practices. To reveal the permanent displacements, special data processing schemes based on removal of the baseline shifts in separated time windows were proposed. In this study, the most recently proposed data processing scheme eBASCO (Schiappapietra et al., 2021) is improved and the effectiveness of the new scheme is tested by comparing the obtained displacements on the processed records with those derived from nearby GPS data for 25 records from worldwide earthquakes.

 Preliminary site screening efforts and geodetic observations demonstrated that the earthquake sequence of February 6, 2023 in Turkey caused remarkable permanent displacements, which might be one of the reasons for severe damage and collapse of the structures, especially those which have long fundamental periods such as pipelines, roadways and high-rise buildings. In this study, near fault records of the earthquake sequence are processed with the proposed scheme and the obtained permanent displacements are evaluated with those predicted by existing models.