MVs constitute natural laboratories for investigating several poorly understood processes, such as geochemical and physical dynamics during ongoing eruptions, the interaction between faulting and fluid reservoirs, the hydrological cycle or periodic inflation-deflation cycles at the crustal scale (e.g., those driven by Earth tides), as well as their buried structure.
MVs are often hosted within Nature Reserves that provide a safe environment for monitoring activities, whose main goal is to intercept potential precursors of paroxysmal events. Moreover, since these Reserves are visited by many people every year, monitoring is crucial not only for scientific purposes but also for ensuring the safety of visitors and nearby populations.
This session is addressed to investigations of:
- the reconstruction of the deep engine dynamics of MV activity and their stratigraphic structure;
- the processes that form mud volcanos and drive material migration to the surface;
- the hydrological regime and its influence on MV activity;
- outcomes from long-term monitoring and spot-survey;
- the interplay between the regional/local seismicity and MV activity, as manifestation of crustal dynamics;
- the remote sensing terrain and surface modeling, and geophysical imaging;
- the impact of MVs activity on ecosystems and climate.
Multidisciplinary approaches to the MVs study, aimed at identifying reliable indicators of their activity state, are welcome.
Posters on site: Fri, 8 May, 10:45–12:30 | Hall X2
Mud volcanoes are key geo-environmental features, particularly in central Italy, where their origin is linked to the interaction between tectonics, fluid migration, and high sedimentation rates. In the Monteleone di Fermo area (Marche Region), these structures are aligned with active thrust faults and anticlines of the Marche–Abruzzi system. Despite their relevance as geo-heritage sites and their potential as geohazard indicators, a significant gap persists in the knowledge of their subsurface architecture. Previous studies have focused primarily on compositional aspects and geomorphological descriptions, proposing contrasting triggering and fluid transport mechanisms.This work constitutes a pioneering study in the geophysical characterization of the Monteleone di Fermo mud volcanoes, aiming to define their near-surface geometry and distribution. A multi-parametric approach was applied, integrating full-waveform 3D Electrical Resistivity Tomography (ERT) and 2D seismic refraction tomography (P- and S-wave velocities). Results show distinctive geophysical signatures associated with the system’s saturation state and mud accumulation. The 3D ERT imaging, reaching effective depths of nearly 100 m, shows a slight resistivity contrast between mud bodies (ρ = 10–15 Ω·m) and the hosting clay-rich deposits with lower resistivity (ρ = 8–10 Ω·m). Seismic tomography reveals a marked contrast between the mud edifice and the hosting sediments. In particular, Poisson’s ratio increases (ν > 0.45), indicating the presence of fully saturated muds intruding the clay-rich sediments (ν = 0.35–0.40).These results demonstrate both the feasibility and limitations of full-waveform geo-electrical data for deep 3D resistivity imaging in clay-rich sediments, testing the detectability of mud-volcano structures under low resistivity-contrast conditions. The study further benchmarks sensitivity against complementary seismic indicators (Vp/Vs and Poisson’s ratio), supporting a multi-physics strategy for resolving fluid-migration pathways in challenging near-surface settings.
How to cite: Zambrano, M., Arellano, H., Torres, D., Lucci, N., Ughi, A., Arias, A., Ramos, S., and Mateus, Y.: Imaging near-surface geometry of mud volcanoes: a multi-method geophysical study from Monteleone di Fermo (Marche Region, Italy), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17807, 2026.
Salse di Nirano (Fiorano Modenese, Italy) host one of the largest mud volcano fields of Europe. They are positioned upon an anticline structure of the NE-verging fold-and-thrust Northern Apennine belt and emit fluids mainly consisting of clay mud, saline water and hydrocarbons (liquid and gas). Like most of the world’s mud volcanoes, their gas emissions are primarily composed of methane (> 98%), with minor contributions from carbon dioxide, nitrogen, and other hydrocarbons (Mazzini and Etiope, 2017). Two main fault and fracture systems (one NW-SE oriented and the other SW-NE/ENE-WSW oriented) allow fluids migration to the surface (e.g., Bonini, 2008). From a geomorphological point of view, Salse di Nirano are placed within a caldera-like depression presumably formed by progressive collapse due to degassing (e.g. Bonini, 2008) or as the final stage of mud diapir evolution (Castaldini et al., 2005).
As many world’s mud volcanoes, Salse di Nirano activity is closely linked to tectonic processes (Martinelli and Ferrari, 1991; Bonini, 2009). With the aim of studying the interplay between geofluids and seismicity, a multiparametric monitoring system was set up in 2023. Two distinct mud pools were selected for the continuous monitoring of mud level/density, temperature and electrical conductivity. In addition, a permanent station measuring CO2 flux diffused by the soil was installed at the edge of the mud volcanoes field, where higher gas fluxes were detected (Ferrari et al., 2024). Recently, the station has been upgraded with a methane sensor. A meteorological station and a velocimeter were installed to monitor the atmospheric parameters and the seismic activity of the area, respectively.
Overall, the multiparametric monitoring system continuously recorded about two years of data. Periodic oscillations were identified, with some anomalous variations of mud level, temperature, electrical conductivity and soil gas flux that have been compared with environmental data (meteorological and soil-related) and seismicity. Notably, synchronous changes in mud pools electrical conductivity and soil CO2 fluxes were detected in relation to two distinct seismic swarms occurred in February and August 2024. In addition, differences in the behaviour of the two mud pools were also observed throughout all the time-series and presumably point to extremely local conditions influencing the common feeding system. All these observations highlight the efficiency of the presented continuous multiparametric monitoring system in inferring new insights on mud volcano crustal fluids dynamics. This work reports the results achieved in the framework of the INGV-MUR project Pianeta Dinamico.
References
Bonini, M.; 2008: Geology Vol. 36, pp. 131-134, https://doi.org/10.1130/G24158A.1.
Bonini, M.; 2009: Tectonophysics Vol. 474, pp. 723-735. doi:10.1016/j.tecto.2009.05.018.
Castaldini, D., Valdati, J., Ilies, D.C., Chiriac, C., Bertogna, I.; 2005: Italian Journal of Quaternary Sciences Vol. 18, n. 1, pp. 245-255.
Martinelli, G., Ferrari, G.; 1991: Tectonophysics Vol. 193, n. 4, pp. 397-410, https://doi.org/10.1016/0040-1951(91)90348-V.
Mazzini, A., Etiope, G.; 2017: Earth-Science Reviews Vol. 168, pp. 81-112, http://dx.doi.org/10.1016/j.earscirev.2017.03.001.
Ferrari, E., Massa, M., Lovati, S., Di Michele, F., Rizzo, A.L.; 2024: Frontiers in Earth Science Vol. 12, n. 1412900, pp. 1-26, https://doi.org/10.3389/feart.2024.1412900.
How to cite: Ferrari, E., Rizzo, A. L., Capelli Ghioldi, G., Sciarra, A., Tamburello, G., Viveiros, F., Lovati, S., and Massa, M.: Earthquake-related fluids behaviour at Salse di Nirano mud volcano field (Italy), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1738, 2026.
Mud volcanoes represent key natural pathways for the transfer of deep-seated fluids to the surface, yet their gas composition and degassing behavior can vary significantly depending on geological setting and post-genetic processes. Here we present a comparative geochemical and monitoring-based study of mud volcano systems from Azerbaijan and Northern Italy, integrating molecular composition, stable isotopes (δ¹³C-CH₄, δ²H-CH₄, δ¹³C-CO₂) and soil gas flux measurements, to investigate the dynamics of crustal fluid circulation and the release of climate-relevant gases to the atmosphere.
Azerbaijani mud volcanoes are characterized by CH₄-dominated gases with variable contributions of CO₂ and higher hydrocarbons, wide ranges in C₁/C₂⁺ ratios, and isotopic signatures indicating predominantly thermogenic methane, locally affected by secondary microbial processes and mixing during migration. These systems commonly display significant and spatially focused CH₄ and CO₂ fluxes, reflecting active and deep-rooted fluid pathways, and highlighting an efficient transfer of deep fluids to the atmosphere and a potentially significant role in natural greenhouse gas emissions.
Northern Italian mud volcanoes are also characterized by CH₄-dominated gases with low content of CO₂ and wide ranges of C₁/C₂⁺ ratios, but isotopic signatures indicate a dominant secondary microbial methane origin, associated with biodegradation of hydrocarbons and subsequent methanogenesis, producing isotopically heavy CO₂. Soil gas flux measurements are generally lower than those reported for Azerbaijan mud volcanoes, suggesting that deep-sourced gases are largely attenuated by shallow processes and limited near-surface permeability.
The comparison highlights how mud volcanoes with similar surface expressions can reflect markedly different subsurface processes, fluid sources and degassing dynamics. These results emphasize the importance of integrated geochemical characterization and monitoring to 1) properly assess mud volcano activity, 2) their contributions to greenhouse gas emissions and 3) their environmental and societal implications including associated geohazards.
How to cite: Sciarra, A. and Mazzini, A.: Comparative gas geochemistry and degassing behavior of mud volcanoes: insights from Azerbaijan and Northern Italy, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8482, 2026.
Natural gas seeps and mud volcanoes are widely distributed across terrestrial and shallow submarine sedimentary basins and contribute considerable amounts of fossil methane to the atmosphere. Methane emissions from these systems are commonly interpreted as dominantly thermogenic in origin; however, microbial activity may significantly contribute to, or overprint, these emissions through secondary methanogenesis or methane oxidation during gas migration and storage.
Conventional bulk isotope composition (δ¹³C and δD) and hydrocarbon concentration ratios are often insufficient to distinguish secondary microbial contributions from an initial thermogenic source. Independent of bulk isotopic signatures, methane clumped isotopes (Δ¹³CH₃D and Δ¹²CH₂D₂) provide direct constraints on methane formation pathways and post-generation alteration processes. Recent studies have revealed low-temperature near-equilibrium clumped-isotope signatures in mud-volcano systems in Azerbaijan1, indicative of strong microbial overprinting, whereas methane from Japanese mud volcanoes exhibits clumped isotope signatures spanning from far from equilibrium to near equilibrium values2. For the latter, clumped isotope signatures of methane correlate with 13C-position-specific isotope composition of propane, suggesting the biodegradation of higher hydrocarbons is associated with progressive modification of methane clumped isotopes.
Here, we investigate methane emissions from mud volcanoes and gas seeps in central and southern Italy (n = 14) and Romania (n = 15). Methane bulk and clumped isotope composition (δ¹³C, δD, Δ¹³CH₃D and Δ¹²CH₂D₂) are analyzed using a quantum cascade laser absorption spectrometer (QCLAS) equipped with a customized gas-inlet system at Empa3. Propane concentrations span from below detection to 0.8%, indicating a wide range of potential microbial influence. Selected samples are further characterized by propane position-specific isotope analyses at Science Tokyo following established protocols by Gilbert et al. 4, providing constraints on the extent of secondary microbial processes affecting higher hydrocarbons.
Preliminary clumped-isotope results from Italian mud volcanoes indicate near-equilibrium signatures consistent with strong microbial influence, comparable to patterns reported from Azerbaijan mud-volcano systems. In contrast, Romanian samples exhibit pronounced variability in propane concentrations, providing a critical test case to explore whether methane clumped-isotope systematics transition toward more thermogenic-dominated patterns with secondary microbial influence, similar to those observed in Japanese systems. By integrating new datasets from Italy and Romania with published clumped-isotope and propane intramolecular isotope data, this study explores whether microbial influences on methane emissions follow consistent or system-specific patterns across mud-volcano and gas-seep systems globally.
[1] Liu et al., 2023 Geology
[2] Gilbert et al., 2025 EGU2025 Abstract
[3] Zhang et al., 2025 Anal. Chem.
[4] Gilbert et al. 2019 Proc. Natl. Acad. Sci.
How to cite: Zhang, N., Meissner, J., Kueter, N., Bernasconi, S., Emmenegger, L., Baciu, C., Lupulescu, A., Sciarra, A., Grassa, F., Mazzini, A., Gilbert, A., Yamada, K., Ueno, Y., and Mohn, J.: Clumped isotope signatures of methane from mud volcanoes in Italy and Romania: implications for microbial activity , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5050, 2026.
This study presents a comparative analysis of the two key example of sedimentary volcanism in Italy: the mud volcanoes of Salse di Nirano (Northern Italy) and the Maccalube of Aragona (Sicily). Mud volcanoes are not related to magmatic activity but result from the ascent of gas, mainly methane, which transports mud, water and fine-grained sediments to the surface These systems represent natural laboratories for investigating subsurface fluid migration, gas-driven processes, and their surface expressions.
At both sites, mud and fluid samples were collected to perform geochemical, mineralogical, magnetic, and paleontological analyses, providing integrated constraints on fluid sources, sediment provenance, and mud volcano dynamics
Despite their apparent similarities, the two sites display markedly different genetic mechanisms and activity style. The study is carried out within the framework of the INGV-MUR project Pianeta Dinamico, called PROMUD.
The Nirano mud volcanoes are characterized by slow and persistent activity, forming small and stable mud cones and bubbling pools. This behavior reflects the compressional tectonic setting of the Northern Apennines, where fractures facilitate the upward migration of fluids and hydrocarbons. The extruded material mainly consists of ARGILLE SCAGLIOSE, the main constituent of the volcanoes, marly clays rich in CaCO3, and Plio-Pleistocene clay sediments, while saline waters indicate an ancient marine depositional environment.
In contrast, the Maccalube of Aragona area exhibits highly variable and sometimes violent activity, with bubbling mud pools and sudden eruptive events. Here, the mud composition derives from poorly consolidate shallow clayey sediments, and methane is generated within organic-rich sediments. Brackish waters are likely derived from compaction processes of marine sediments.
The comparison highlights how similar fluid-driven process can produce contrasting surface features, levels of activity and hazard scenarios.
How to cite: Misiti, V., Pinzi, S., Sciarra, A., Grassa, F., Cascella, A., and Venuti, A.: Mud volcanoes as natural laboratories for fluid-driven processes: a comparison between Nirano and Aragona (Italy), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5222, 2026.
Halophytic species thriving in these environments display remarkable phytochemical resilience through specialized metabolite production. In Atriplex sagittata Borkh. (Nirano), 64 compounds, including flavonoids and phenylethylamine alkaloids, were identified. Sulfated flavonoids and alkaloids were enriched in populations exposed to higher salt inputs (Na⁺, Cl⁻, Br⁻). Similarly, Puccinellia fasciculata (Torr.) E.P.Bicknell exhibited enhanced production of sulfated flavonoids and alkaloids in the more saline soil of Ferdinando cone, and its polar extract inducing up to 85.3% mortality in Drosophila melanogaster, indicating environmentally triggered bioactive defenses. We studied the metabolome of Lavatera agrigentina Tineo and Suaeda vera Forssk. ex J.F.Gmel collected in Maccalube Nature Reserve and in a nearby stress-free environment. Analysis of the hydroalcoholic extract of S. vera using by LC-MS revealed a rich phytochemical profile, including flavonoids and sulphated flavonoids, phenylethylamine alkaloids and phenolic compounds. Similarly, HR-ESI-MS analysis of L. agrigentina identified metabolites such as flavonoids, coumarins, and terpenes. Comparative analysis showed that plants from the stress-free environment produced lower levels of abscisic acid, glycosylated, and sulphated derivatives.
Radionuclide measurements in soils, mud and water pools complemented the botanical observations, revealing significant site-specific behavior. High concentrations of radon (²²²Rn) were detected exclusively at active mud emission centers, correlating with gas bubbling flows. Gamma spectrometry of mud, soil, and plant tissues (226Ra, ²³²Th, ⁴⁰K, 137Cs) indicated generally homogeneous distributions; however, ⁴⁰K levels in dried plants were linked to biological activity, suggesting an interplay between vegetation and the radioactive properties of volcanic substrates.
This study, conducted on both Nirano and Maccalube Nature Reserves, was supported by the PROMUD (PROtocol for MUD volcanoes) project, funded by the Italian Ministry of University and Research INGV Pianeta Dinamico Project. The results show how the plant species, particularly halophytes, can modulate their specialized metabolite pathways in response to environmental stressors in sedimentary volcanic settings. These findings underscore the value of sedimentary mud volcanoes as natural laboratories for studying environmental stress adaptation and biogeochemical interactions.
How to cite: De Lauro, E., Falanga, M., Alizadeh, Z., De Tommasi, N., Forlano, P., Giunti, G., Gucciardo, D., Rosa, E., Mancini, S., Sciarra, A., and Cusano, P.: Biodiversity and Environmental Stressors: Some applications to mud volcanoes, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-17707, 2026.
We describe the design, implementation, and evaluation of a combined monitoring tasks to better understand a mud volcano (MV) activity, in the framework of INGV Pianeta Dinamico – MT-PROMUD project. The study site is the Maccalube d’Aragona (Sicily, Italy) protected reserve, hosting a MV field. Maccalube MV is characterized by continuous low-energy emissions of mud, water and gases (mainly CH4) as well as episodic paroxysmal eruptions. During the 2014 paroxysm, two children were buried by the mud fallout, and the site has been under judicial seizure for several years, until early 2025.
Starting from 2023, we carried out a series of pilot studies and consultations to design a monitoring network and to plan simultaneous acquisitions of multidisciplinary signals and spot surveys. The resulting monitoring strategy includes: 1) permanent instrumentation, acquiring in a continuous mode, seismic signals, meteorological parameters, soil temperature, apparent volumetric water content, Temperature, Electric Conductivity and water column pressure (CTD) in the mud pool; 2) mobile devices, for spot acquisitions of mud emitting vents positions (GNSS), tromographies, hydrophone recordings for acoustic soundscape characterization, apparent soil volumetric water content and environmental radioactivity measures, (focused on 222Rn and 220Rn emissions), and geoelectrical tomographies; 3) sample collections of plants for metabolomic analysis, water and gas emitted from MV and mud pools for chemical and isotopic analyses, mud for magnetic, micropaleontological and mineralogical investigations. All spot surveys were documented with photographic reportages.
This monitoring system enabled the acquisition of high quality and unique data associated with the paroxysmal eruption of 29 August 2025, as well as variations in MV activity in occasion of a local earthquake.
Our combined and multidisciplinary approach provided a comprehensive picture of mud volcanoes functioning and can serve as a model to assess the need for future monitoring of other mud volcanoes.
How to cite: Bellucci Sessa, E. and the Maccalube Team: The Maccalube d’Aragona mud volcano Monitoring System, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13197, 2026.
On 22–23 April 2025, a seismic noise survey was carried out at the Maccalube di Aragona mud volcano field (Sicily, southern Italy), with the aim of investigating the characteristics of the background seismic signal related to vent activity, and the shallow subsurface structure. The experiment, named DEMETRA (DEnse MaccalubE TRomino Acquisition), was conducted within the INGV–PROMUD multidisciplinary research project, aimed at identifying diagnostic indicators of mud volcano activity and potential precursors of paroxysmal events. Ambient seismic noise was acquired at 21 sites using three-component, 24-bit digital tromograph deployed with a high spatial density across vent zones and surrounding areas. The data analyses include spectral characterization, horizontal-to-vertical spectral ratio (HVSR) computation, and estimate of the polarization pattern of the recorded signals. The HVSR results do not reveal distinct amplification peaks but instead show site-dependent deamplification features. Polarization analysis highlights coherent directional patterns within the vent areas. Furthermore, transient signals embedded in the background noise were detected at some sites; their spectral content and polarization properties suggest a possible association with degassing processes, mud emissions, or surface bubbling phenomena. Owing to its dense spatial coverage, the DEMETRA experiment provides a valuable dataset for improving the understanding of subsurface properties and dynamic processes in active mud volcano systems.
How to cite: Petrosino, S., Cusano, P., Madonia, P., and Gucciardo, D.: DEMETRA - A Seismic Noise Survey at the Maccalube di Aragona Mud Volcanoes: Results and Perspectives, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16824, 2026.
Mud volcanoes are highly dynamic geohazard environments in which surface conditions can change over very short timescales due to episodic mud extrusion, flow, drying, cracking and oxidation. The resulting landscapes are spatially heterogeneous and typically include mixtures of fresh and weathered mud, crusted deposits, bare soil and dense or sparse vegetation. Considering the opportunities offered by deep learning for environmental monitoring, a consistent categorization of these surfaces is essential to quantify spatial patterns through time and to assess the evolution of active areas. However, progress is often limited by the lack of high quality, domain-specific labelled datasets. This gap slows the adoption of deep learning models in specialized environmental settings such as mud volcanoes, because the most readily available training datasets are largely drawn from urban and human-centered contexts. While manual annotation can partially compensate for limited training data, it is labor-intensive and difficult to standardize across operators, especially where class transitions are gradual and boundaries are diffuse rather than sharp.
This study investigates how multispectral orthophotos can support separation of key mud volcano surface features and thereby accelerate mask creation for dataset generation. We present a case study at the Aragona mud volcano field (Sicily, Italy), called the Maccalube, using imagery acquired with a DJI Mavic 3 Multispectral and processed into an orthomosaic with Agisoft Metashape. We first evaluated common soil and vegetation oriented spectral indices as separability baselines. In this setting, however, baseline indices can be ambiguous because wet clay-rich substrates and thin surface water films may yield intermediate responses that overlap low cover vegetation. We additionally tested common rapid segmentation methods on the RGB orthomosaic including K-means, Simple Linear Iterative Clustering and Segmentate Anything. These algorithms show poor performance, often merging distinct classes and fragmenting individual ones, which requires substantial manual correction.
We therefore introduce a practical band combination that integrates information from the visible channels with the red-edge and near-infrared bands to improve discrimination between vegetation, wet mud and drier or more weathered mud areas. The calculation is constructed in two steps: first, the visible channels are combined into a neutrality term that increases when RGB responses are similar (low color contrast). Second, this term is multiplied by an inverted red-edge contrast component derived from the near-infrared and red-edge bands, reducing the output where a strong red-edge rise is present. The result of the proposed band combination is a pre-labelling layer that can be thresholded to generate candidate masks with improved vegetation suppression. Remaining ambiguities are mainly confined to non-vegetated materials with similar dark appearance, including very fresh dark mud versus other bare substrates. Overall, the workflow offers a practical way to accelerate mask creation in domains where labelled data are limited. It supports the rapid development of domain specific training datasets for deep learning applications, in light of future automated monitoring of these environments.
How to cite: Guastella, M., Martorana, R., Pisciotta, A., and D'Alessandro, A.: Multispectral pre-labelling workflow for mud volcano training datasets: a case study at the Maccalube of Aragona, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12274, 2026.
