Geomorphological and Thermal Monitoring of Mud Volcano Landscape with UAV Technologies

The mud volcanoes in Romania are among the most well-preserved and accessible mud volcano fields in Europe. They represent important natural heritage and, at the same time, offer a unique natural laboratory for studying the interplay between tectonics and hydrocarbon fluid escape in an active geological setting. However, these mud volcanoes remain understudied. Here, we present an integrated UAV approach (LiDAR, photogrammetry, thermal imaging) to investigate relevant aspects of the Pâclele Berca, Mici, Mari, and Beciu located in Buzău Land UNESCO Global Geopark, Romania.

The Pâclele Mici mud volcano is an area of complex geology shaped by tectonic phases from the Late Cretaceous and Early Miocene periods. Situated on the Berca–Arbanasi anticline near the seismically active Vrancea zone, this site is geologically significant as it represents an interaction of methane-rich fluids with neotectonic faults and is possibly still influenced by a seismogenic area, creating a dynamic and unique environment.

In 2024, UAV-mounted LiDAR, photogrammetry, and thermal sensors were deployed to collect high-resolution spatial and thermal data over the Pâclele Mici site. The LiDAR system provided precise digital elevation models, revealing subtle patterns of surface deformation, including subsidence and uplift, that evolve with mud volcanic activity. Photogrammetry generated detailed orthomosaics, allowing for an in-depth assessment of surface morphology, textures, and fissures. Thermal imaging highlighted temperature anomalies linked to active venting and subsurface fluid movement, offering insights into the system's thermal behavior and energy flux. These datasets revealed significant surface deformation and distinct thermal anomalies concentrated around active vents when analyzed together. Subsidence and uplift patterns correlated with zones of intense fluid discharge, aligning with findings from previous deep geoelectrical surveys.

By combining spatial, morphological, and thermal datasets, this research provides a holistic view of the Buzau Land Geopark mud volcanos, enhancing our understanding of their evolution and the mechanisms driving their activity. The findings underscore the importance of remote sensing technologies in studying dynamic geological systems and contribute valuable insights into the broader implications of mud volcanism, including its role in methane emissions, landscape evolution, and geological hazards. This multidisciplinary approach sets a foundation for future studies and monitoring efforts at Pâclele Mici and globally in similar active settings.

Keywords:  Remote Sensing,  UAV Technologies, Mud Volcano

Acknowledgments: This work was done in the framework of the National Research Program, project SOL4RISC no. PN 23360301