Search Results (174)

Saudi Arabia is experiencing interactions between ongoing urbanization, tourism growth, infrastructure projects in western regions along the Red Sea, and volcanic hazards. The area contains extensive monogenetic volcanic fields with hundreds of volcanoes formed during the Quaternary period. The large scale of the region often limits and fragments volcanological research, resulting in insufficient age and chemical data to understand the spatial and temporal development of many volcanic fields. Increased tourism has created a need for volcanic hazard assessments, particularly since some volcanic fields are considered possible tourist destinations. Harrat Lunayyir, in northwestern Saudi Arabia, is an example where such assessments have been conducted. Hazard assessments seek to provide information about potential future eruption types, locations, and impacts over timeframes relevant to urban planning and risk management. Due to rapid local development, these assessments may be required on short notice for specific small areas within larger volcanic fields, even when geological data are limited. This report presents a deterministic, scenario-based method for addressing such requests in the Lunayyir Volcanic Field. Results indicate a young Holocene eruption site characterized by a complex scoria cone associated with lava spattering, Strombolian, violent Strombolian activity and extensive transitional-type lava effusion. Full article

Lava flows represent complex thermofluid phenomena in which surface cooling leads to the formation of a solidified surface layer. Understanding the influence of such a surface layer on fluid flow is an important issue in lava flow modeling. It also shares essential characteristics with a wide range of engineering problems involving surface solidification. However, the role of plastic surface skin in controlling flow deceleration and stopping behavior has not been sufficiently clarified in existing models. In this study, two-dimensional smoothed particle hydrodynamics (SPH) simulations were conducted to investigate the influence of surface skin formation on lava flow dynamics. The temperature dependence of viscosity was introduced to reproduce a plastic surface skin. The skin was represented as a low-temperature, high-viscosity region. Comparisons with simulations without surface skin formation demonstrated that the surface skin exhibits a suppressive effect on the flow. This behavior was consistent with qualitative observations of flowing lava. It was also found that this surface skin caused the successive deceleration characteristic in Bingham fluids. As a result, both the flow velocity and the flowing distance are affected. These results suggest that accurate lava flow simulations require models that incorporate both surface skin effects and non-Newtonian behavior. Full article

The lack of high-precision imaging data for lunar volcanic regions currently hinders the detailed characterization of lava tube systems and their associated fine-scale geomorphology. To address this information deficit, this study establishes the Jingpo Lake Volcanic Field (JLVF) in Northeast China as a primary terrestrial analog for the lunar Marius Hills complex. We systematically characterize the basaltic morphometric continuum, tracing the geological evolution from proximal scoria cones through medial lava tube skylights to distal lava plateaus. Focusing on the subsurface transport system, we identify a linear chain of discontinuous skylights that structurally mirrors the “proto-rille” stage of lunar sinuous rilles. Quantitative morphometry reveals that these terrestrial vents reproduce the geometric duality of lunar pits, ranging from stable “deep shafts” to degraded “funnel pits,” effectively validating the mechanical diversity of the lunar inventory. Critically, the “U-to-V” cross-sectional transition observed in JLVF collapse trenches serves as diagnostic ground-truth evidence, confirming that lunar rilles originate from the catastrophic roof failure of subsurface tubes rather than purely thermal erosion. Regarding the lava plateau, our field investigation resolves sub-meter micro-textures—including laminar pahoehoe ropes and inflation fissures—that are typically obscured by the resolution limits of current lunar orbiters. These findings suggest that the seemingly “smooth” lunar maria likely host complex, rugged micro-terrains. Therefore, comparing lunar volcanic regions with simulated volcanic fields from Earth is crucial. Analyzing potential volcanic products from angles undetectable by some lunar satellites can offer vital insights for future lunar exploration. Full article

Mt. Etna is the highest and most active stratovolcano in Europe, located in Catania (Sicily, Italy). Its persistent degassing, frequent explosions, and lava flows release large amounts of ash and gases into the atmosphere. This study aimed to assess whether chronic exposure to local volcanic emissions leads to an increased internal dose of trace elements (As, Ba, Be, Bi, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, Tl, U, V, W, Zn) in Catania adult residents. To this end, urine samples were collected from 167 individuals residing in Catania and compared with 193 residents of other Sicilian areas located farther from the volcano. Results revealed significantly higher urinary concentrations of As, Hg, Mn, Pb, and Tl in the exposed group, suggesting volcanic activity as a relevant source of exposure. The levels of the other elements were instead affected by other factors such as lifestyle habits and the consumption of specific foods and beverages. The urinary concentrations of trace elements were consistent with reference values reported in other European studies, and the levels remained well within the health-based guidance values. There is evidence of an increased internal dose of a few elements in the Sicilian population exposed to volcano activity, but the observed increases are unlikely to pose a significant health risk. Full article

In this paper, we propose the Adaptive Volcano Support Vector Machine (AVSVM)—a novel classification model inspired by the dynamic behavior of volcanic eruptions—for the purpose of enhancing malware detection. Unlike conventional SVMs that rely on static decision boundaries, AVSVM introduces biologically inspired mechanisms such as pressure estimation, eruption-triggered kernel perturbation, lava flow-based margin refinement, and an exponential cooling schedule. These components work synergistically to enable real-time adjustment of the decision surface, allowing the classifier to escape local optima, mitigate class overlap, and stabilize under high-dimensional, noisy, and imbalanced data conditions commonly found in malware detection tasks. Extensive experiments were conducted on the UNSW-NB15 and KDD Cup 1999 datasets, comparing AVSVM to baseline classifiers including traditional SVM, PSO-SVM, and CNN under identical computational settings. On the UNSW-NB15 dataset, AVSVM achieved an accuracy of 96.7%, recall of 95.4%, precision of 96.1%, F₁-score of 95.75%, and a false positive rate of only 3.1%, outperforming all benchmarks. Similar improvements were observed on the KDD dataset. In addition, AVSVM demonstrated smooth convergence behavior and statistically significant gains (p < 0.05) across all pairwise comparisons. These results validate the effectiveness of incorporating biologically motivated adaptivity into classical margin-based classifiers and position AVSVM as a promising tool for intelligent malware detection systems. Full article

This study probabilistically assesses magma ascent by modeling dike propagation as a fully coupled fluid-flow, thermo-mechanical problem, explicitly accounting for the stochastic heterogeneity of the crustal host rock. We study felsic (rhyolite) lava flow and two distinct basaltic feeding regimes that correspond to the conditions necessary to produce the contrasting pāhoehoe and ʻaʻā surface morphologies. Basaltic dikes demonstrate high propagation efficiency to the surface (pāhoehoe-feeding regime 99.5%; ʻaʻā-feeding regime 97.5%), whereas rhyolite dikes have an 89% failure rate, attributed to significant friction. Both regimes represent distinct constructal approaches aimed at maximizing flow persistence. The pāhoehoe-feeding regime is a thermally regulated, stable design characterized by low-velocity, cooling-dominated dynamics. Its slow, persistent flow allows for significant conductive heating of the surrounding rock wall, creating an efficient, pre-heated thermal conduit. In contrast, the ʻaʻā-feeding regime is a mechanically dominated design governed by high-velocity, stochastic dynamics. This morphology is driven by forceful flow, and its thermal budget is supplemented by intense viscous dissipation (internal friction). Rhyolite magma flow fails upon losing constructal viability, driven by a coupled mechanical–thermal cascade. The sequence begins when a mechanical barrier halts the magma velocity, which triggers a freezing event and leads to permanent arrest. Full article

The Monastery of San Nicolò l’Arena in Catania, a UNESCO World Heritage site, embodies a complex architectural and historical stratigraphy, reflecting successive construction phases, functional changes, and the impact of catastrophic events, including the 1669 lava flow and the 1693 earthquake. As part of the CHANGES project, this study combines historical–archaeological research with non-invasive in situ scientific analyses to investigate the materials and the conservation state of the monumental complex. Stratigraphic analysis identified multiple masonry and plaster units, allowing the reconstruction of five main construction phases and related functional changes. Portable X-ray Fluorescence (pXRF), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT), and handheld optical microscopy provided rapid insights into the chemical and mineralogical composition of plasters and mortars, highlighting lime-based binders with variable aggregate, including volcanic clasts, sand, and cocciopesto. In situ diagnostic analyses allowed us to distinguish pre- and post-earthquake materials, while historical data contextualized construction phases and functional transformations. The integration of archaeological and scientific approaches proved to be complementary: historical evidence guides the selection of analytical targets, while diagnostic results enrich and validate the interpretation of the building’s evolution. This interdisciplinary methodology establishes a robust framework for the understanding and valorization of complex cultural heritage sites. Full article

Since March 2021, a series of volcanic eruptions on Iceland’s Reykjanes Peninsula has repeatedly triggered wildfires in moss-dominated heathlands—an unprecedented phenomenon in this environment. These fires have consumed extensive organic material, posing emerging health risks and long-term ecological impacts. Using high-resolution multispectral satellite data from the Copernicus program, we present the first quantitative assessment of the spatial and temporal dynamics of volcanic wildfire activity. Our analysis reveals a cumulative burned area extending 11.4 km² beyond the lava flows, primarily across low-relief terrain. Time series of the Normalized Difference Vegetation Index (NDVI) capture both localized fire scars and diffuse, landscape-scale burn patterns, followed by slow and spatially heterogeneous recovery. Complementary ground surveys conducted in August 2024 document diverse post-fire successional pathways, with vegetation regrowth and species composition strongly governed by microtopography and substrate texture. Together, these results demonstrate that volcanic wildfires represent a novel and consequential secondary disturbance in Icelandic volcanic systems, highlighting the complex and protracted recovery dynamics of moss heath ecosystems following fire-induced perturbation. Full article

Krenitsyn Peak is one of the two active volcanoes on Onekotan Island (Greater Kuril Ridge). The inaccessibility of the island, along with the volcano being situated within a sizeable (7 km in diameter) and cold (3.7 °C) caldera lake, has led to minimal research on the area. We present the first detailed characterization of the rocks from the only historical eruption of Krenitsyn Peak (November 1952) and a brief description of the ancient lava and pyroclastic density current (PDC) deposits that make up the building of the volcano. The 1952 eruptive products are represented by two-pyroxene andesites (59.2–63.3 wt.% SiO₂), and the older lava and pyroclastic flow rocks consist of two-pyroxene andesites and dacites (62–67.6 wt.% SiO₂). Almost all samples belong to the calc-alkaline, medium-K, and medium-Fe series, and the pumiceous lapilli from the 1952 eruption fall into the low-Fe series. The minerals exhibit signs of magma mingling, including relic high-Ca (up to An₉₂) plagioclase cores with signs of dissolution and recrystallization, and oscillatory-zoned pyroxene. Full article

This study presents a cohesive physical model that predicts lava flow morphology by establishing a quantitative link between a lava’s yield strength and its geometric complexity, measured by a prefractal dimension. The model is founded on the principle of symmetry, where the potential for fracturing and complexity peaks at an intermediate yield strength. This peak in complexity, observed with a predicted prefractal dimension (D_pf) of 1.15 for terrestrial ‘a’ā-like lava, arises from a critical state where a balance between gravitational driving forces and internal resistance allows for the formation of intricate margins. The model demonstrates that as lavas deviate from this optimal strength, becoming either too fluid (pāhoehoe, D_pf = 1.05) or too rigid (rhyolite, D_pf = 1.07), their morphology becomes progressively simpler, representing a symmetrical decline in complexity. Our approach also incorporates the overriding influence of topographic confinement and the temporal evolution of complexity as the lava cools. Validated against terrestrial lavas and successfully applied to lower-gravity environments, the model predicts a reduction in complexity for similar flows on Mars (D_pf = 1.13) and the Moon (D_pf = 1.09), providing a tool for interpreting volcanic processes grounded in the fundamental principles of symmetry and complexity. Full article

The Lunayyir Volcanic Field (Harrat Lunayyir), located on the western boundary of the Arabian Microplate, comprises a Quaternary volcanic region featuring approximately 150 volcanoes formed from around 700 vents. In 2009, a significant volcano-seismic event occurred, resulting in the formation of a nearly 20 km long fissure. Geophysical modeling has demonstrated that this area lies above an eruptible magma system, unequivocally confirming ongoing volcanic activity. Recent geological mapping and age determinations have further established the field as a young Quaternary volcanic landscape. Notably, the 2009 event provided critical evidence of the region’s volcanic activity and underscored the potential to connect its volcanic geoheritage with hazard mitigation strategies. The volcanic field displays diverse features, including effusive eruptions—primarily pāhoehoe and ‘a‘ā lava flows—and explosive structures such as spatter ramparts and multi-crater scoria cones. While effusive eruptions are most common and exert long-term impacts, explosive eruptions tend to be less intense; however, some events have reached a Volcanic Explosivity Index (VEI) of 4, distributing ash up to 250 km. Recognizing the geoheritage and geodiversity of the area may enhance resilience to volcanic hazards through geoconservation, educational initiatives, managed visitation, and establishment of a geoheritage reserve to preserve site conditions. Hazards associated with this dispersed monogenetic volcanic field manifest with recurrence intervals ranging from centuries to millennia, presenting challenges for effective communication. Although eruptions are infrequent, they have the potential to impact regional infrastructure. Documentation of volcanic geoheritage supports hazard communication efforts. Within the northern development sector, 26 geosites have been identified, 22 of which pertain to the Quaternary basaltic volcanic field, each representing a specific hazard and contributing vital information for resilience planning. Full article

Accurate estimation of erupted lava volumes is essential for understanding volcanic processes, interpreting eruptive cycles, and assessing volcanic hazards. Traditional methods based on Mid-Infrared (MIR) satellite imagery require clear-sky conditions during eruptions and are prone to sensor saturation, limiting data availability. Here, we present an alternative approach based on the post-eruptive Thermal InfraRed (TIR) signal, using the recently proposed VRP_TIR method to quantify radiative energy loss during lava flow cooling. We identify thermally anomalous pixels in VIIRS I5 scenes (11.45 µm, 375 m resolution) using the TIRVolcH algorithm, this allowing the detection of subtle thermal anomalies throughout the cooling phase, and retrieve lava flow area by fitting theoretical cooling curves to observed VRP_TIR time series. Collating a dataset of 191 mafic eruptions that occurred between 2010 and 2025 at (i) Etna and Stromboli (Italy); (ii) Piton de la Fournaise (France); (iii) Bárðarbunga, Fagradalsfjall, and Sundhnúkagígar (Iceland); (iv) Kīlauea and Mauna Loa (United States); (v) Wolf, Fernandina, and Sierra Negra (Ecuador); (vi) Nyamuragira and Nyiragongo (DRC); (vii) Fogo (Cape Verde); and (viii) La Palma (Spain), we derive a new power-law equation describing mafic lava flow thickening as a function of time across five orders of magnitude (from 0.02 Mm³ to 5.5 km³). Finally, from knowledge of areas and episode durations, we estimate erupted volumes. The method is validated against 68 eruptions with known volumes, yielding high agreement (R² = 0.947; ρ = 0.96; MAPE = 28.60%), a negligible bias (MPE = −0.85%), and uncertainties within ±50%. Application to the February-March 2025 Etna eruption further corroborates the robustness of our workflow, from which we estimate a bulk erupted volume of 4.23 ± 2.12 × 10⁶ m³, in close agreement with preliminary estimates from independent data. Beyond volume estimation, we show that VRP_TIR cooling curves follow a consistent decay pattern that aligns with established theoretical thermal models, indicating a stable conductive regime during the cooling stage. This scale-invariant pattern suggests that crustal insulation and heat transfer across a solidifying boundary govern the thermal evolution of cooling basaltic flows. Full article

In recent years, significant exploration successes and research progress in volcanic hydrocarbon reservoirs across China’s offshore basins have highlighted their importance as key targets for deep hydrocarbon exploration. In the Shimentan Formation of the Xihu Sag, East China Sea Shelf Basin (ECSSB), low-yield gas flows have been encountered through exploratory drilling; however, no major reservoir breakthroughs have yet been achieved. Assessing the large-scale reservoir potential of volcanic sequences in the Shimentan Formation is thus critical for guiding future exploration strategies. Based on previous exploration studies of volcanic reservoirs in other Chinese basins, this study systematically evaluates the hydrocarbon potential of these volcanic units by microscopic thin section identification, major element analysis, integrates drilling data with seismic interpretation techniques—such as coherence cube slicing for identifying volcanic conduits, dip angle analysis for classifying volcanic edifices, and waveform classification for delineating volcanic lithofacies. The main findings are as follows: (1) The Shimentan Formation is primarily composed of intermediate to acidic pyroclastic rocks and lava flows. Volcanic facies are divided into three facies, four subfacies, and six microfacies. Volcanic edifices are categorized into four types: stratified, pseudostratified, pseudostratified-massive, and massive. (2) Extensive pseudostratified volcanic edifices are developed in the Hangzhou Slope Zone, where simple and compound lava flows of effusive facies are widely distributed. (3) Comparative analysis with prolific volcanic reservoirs in the Songliao and Bohai Bay basins indicates that productive reservoirs are typically associated with simple or compound lava flows within pseudostratified edifices. Furthermore, widespread Late Cretaceous rhyolites in adjacent areas of the study region suggest promising potential for rhyolitic reservoir development in the Hangzhou Slope Zone. These results provide a robust geological foundation for Mesozoic volcanic reservoir exploration in the Xihu Sag and offer a methodological framework for evaluating reservoir potential in underexplored volcanic regions. Full article

Lava rises, locally known as stony rises, are Pliocene–Holocene volcanic landforms occurring throughout the Victorian Volcanic Plain (VVP) in Victoria, Australia. Stony rises are not only important to understanding the geological history of Victoria but are culturally significant to Aboriginal Australians and have ecological importance. Currently, the mapping of stony rises is manually performed at a case study level rather than a landscape level. Remote sensing technologies such as LiDAR data, satellite imagery, and aerial imagery allow for the mapping of stony rises from an aerial perspective. This paper aims to map stony rises using remotely sensed and geophysical data at a landscape level on a younger lava flow (~42,000 years old) within the Victorian Volcanic Plain (the Warrion Hill and Red Rock Volcanic Complex) by utilizing an object based random forest machine learning approach. The results show that stony rises were successfully identified in the landscape to an accuracy of 78.9%, with 2716 potential new stony rises identified. Out of 34 predictor variables, we found the most important variables to be slope gradient, local elevation, DEM of Difference (change in height), Normalized Difference Water Index (NDWI), Clay Mineral Ratio, the concentration of radiometric elements (Potassium, Thorium, and Uranium), Total Magnetic Intensity, and Ecological Vegetation Class (EVC). The results from this study highlight the ability to detect a volcanic landform at a landscape scale using an ensemble of predictor variables that include topographic, spectral information and geophysical data. This lays the foundation towards a uniform approach for mapping stony rises throughout the VVP and similar landforms (such as tumuli) worldwide. Full article

El Malpais National Monument in New Mexico, USA, is a landscape of significant cultural and geological importance, characterized by extensive lava flows, caves, and cinder cones. Despite its harsh terrain, El Malpais holds deep cultural and spiritual meanings for Native American communities, including the Acoma, Zuni, Laguna, and Navajo tribes, whose cosmologies and histories are interwoven with this landscape. Employing a mixed-methods approach combining ethnographic fieldwork with comparative literature studies, this paper documents how these Indigenous groups perceive and interpret interconnected geological features as sacred and meaningful parts of their ancestral heritage. The findings reveal that volcanic landscapes are central not only to cultural origin narratives but also to ongoing rituals, resource use, and pilgrimage practices. This interconnectedness is exemplified by the cultural links between El Malpais and adjacent Mount Taylor, highlighting how geological features form a unified sacred geography. This study positions El Malpais as a culturally animated landscape, where Indigenous epistemologies and spiritual relationships with volcanic landforms challenge conventional notions of geoheritage and call for relational, community-informed approaches to heritage management. Full article