We propose a semiautomatic processing scheme (extended BASeline Correction [eBASCO]) for recovering the tectonic fling from near‐source records. The method, based on a piecewise linear detrend of the strong‐motion (SM) recordings, is applied to reconstruct the ground displacement field of the 30 October 2016 6.5 earthquake in central Italy. The robustness of the results is checked against geodetic measurements, remote sensing data, ground‐motion simulations, and existing empirical models for fling amplitude.
The outcomes of eBASCO are analyzed with the goal of testing its capability to preserve long‐period content in near‐source SM recordings affected by tectonic fling, different from standard processing schemes based on bandpass filtering. Comparison of peak ground displacements, peak ground velocities, and spectral displacements shows that long‐period ground motion recorded over and in proximity of the fault can be underestimated by standard processing. Spectral displacement ordinates can diverge up to the 25% for periods longer than 5 s when an appropriate baseline correction is made.