What’s New from the Recent MW = 4.8 Earthquake in the Lesina Village Area (Apulia, Southern Italy)? Focal Mechanisms and Regression Analysis with Implications for the Seismogenic Source

An MW=4.8 earthquake occurred on 14 March 2025 in the Adriatic offshore from the coastal Lake of Lesina (northern Apulia, southern Italy). According to the National Institute of Geophysics and Volcanology (INGV) database, this event represents the main shock of a seismic sequence that developed within the upper continental crust of the Adria Plate, mainly during spring 2025. Focal mechanisms were calculated for the most energetic earthquakes, and the resulting solutions display consistent kinematic characteristics and similar nodal plane orientations. To investigate the possible seismogenic source, a three-dimensional regression analysis was applied to the spatial distribution of 91 hypocenters from this sequence. This analysis provides a three-dimensional visualization of a best-fit surface, defining its geometry and spatial attitude. The hypocentral distribution closely aligns with one of the two representative nodal planes derived from focal mechanisms. Based on these results and available literature data, a discussion is proposed on the potential seismogenic source. Considering that the Lesina coastal area was struck by a destructive tsunami in the seventeenth century, whose source remains debated, these new observations offer a valuable framework for future seismotectonic studies and improved regional seismic hazard assessment.