Deformation Pattern Modifications Induced by 2021 Brentonico Earthquake: Insights from EGMS Ortho Products

Abstract. Post-seismic deformation reflects the crustal adjustment to stress perturbations induced by earthquakes and may lead to modifications of ongoing deformation patterns. While such effects are well documented for moderate-to-large events, their detectability and significance after low-magnitude earthquakes remain poorly understood. Here, possible deformation pattern modifications associated with the February 2022 ML 3.5 Brentonico earthquake in Northearn Italy are investigated using ground-deformation time series derived from the European Ground Motion Service (EGMS) Ortho products. The earthquake occurrence is treated as a temporal discontinuity, enabling the estimation of pre- and post-event vertical/horizontal differential velocities during 2019-2023. A dual-weighted interpolation scheme, accounting for both spatial proximity and time-series reliability, is applied to derive spatially coherent maps of kinematic modifications. The results reveal measurable and spatially organized changes in deformation patterns, including localized accelerations/decelerations and direction reversals. A clear spatial correspondence between differential velocity anomalies and mapped fault systems suggests that the earthquake acted as a localized stress perturbation, modulating pre-existing tectonic structures. This study demonstrates the capability of EGMS datasets to capture post-seismic deformation signals and highlights the importance of considering low-magnitude events in long-term deformation analyses.