Insights into the Salse di Regnano mud volcanoes: integrating geomagnetism, UAV photogrammetry and historical data

Abstract

This study tries to advance the understanding of the Salse di Regnano mud volcanoes within the framework of an INGV project by integrating geomorphological, geochemical, historical, and remote-sensing data. Detailed analyses of morphology and geochemistry revealed distinctive geometric features and enabled reconstruction of the historical configuration of the area. The research was then extended by integrating drone-based geomagnetic surveys with digitized historical maps transformed into normalized 3D models. High-resolution topography derived from Structure-from-Motion (SfM) photogrammetry, complemented by satellite imagery and archival sources, allowed a comprehensive analysis of surface and subsurface patterns.

The resulting geomagnetic anomaly maps reveal a “tongue” of low values descending from the northern upper slope into the main mud area, which broadly aligns with relative morphological features. Additional anomalies highlight structures of potential geophysical interest for further investigation. Historical reconstruction indicates a markedly different summit in the early 20th century, dominated by a prominent emission cone that reshaped the area following a paroxysmal event in the 1930s.

Building upon previous findings, these new observations continue to provide guidance for subsequent investigations, which will include a targeted geophysical campaign combining passive seismic and electrical resistivity surveys to probe the subsurface. This multidisciplinary approach demonstrates the potential of integrating modern geophysical measurements with historical and morphological information, providing an evolving framework that adapts as new data become available and enhancing our understanding of the evolution of mud volcano systems over time.