Multidisciplinary investigation of the Salse di Regnano mud volcanoes (Northern Italy) using remote sensing and historical data

Abstract

This study presents a multidisciplinary analysis of the Salse di Regnano, a significant mud volcanic area in the Emilia-Romagna Apennines, aiming to develop a comprehensive research strategy to investigate its morphological evolution and fluid emission dynamics. High-resolution 3D models generated through UAV-based photogrammetric surveys enabled detailed mapping and monitoring of morphological features, capturing changes over an extended historical period (1907‑2025) by integrating regional geological maps and archival topographical data. In-situ measurements of methane (CH4) and carbon dioxide (CO2) fluxes revealed localized methane emissions associated with vents characterized by high soil permeability, while CO2 fluxes likely reflect biogenic soil respiration near mud deposits. However, geochemical signatures, including δ13C-CH4 values and the presence of ethane, suggest a thermogenic component, highlighting the complex interplay between biological and geological processes governing gas emissions in the area. Complementary satellite imagery and spatial analyses additionally elucidated the spatial distribution of these processes. This multidisciplinary approach not only advances the understanding of mud volcano dynamics in this geologically active region, but also establishes a practical and scalable methodological framework. The proposed workflow, incorporating targeted geophysical surveys such as geomagnetic and passive seismic measurements, aims to enhance the characterization of subsurface structures. As a preliminary study, this contribution provides a valuable foundation for subsequent monitoring and risk assessment efforts of mud volcanic systems in similar geological contexts. In this view, comparing present-day observations with historical data may also offer critical insights for assessing long-term hazard potential.