Bulletin of Volcanology最新文献

Objective: To evaluate the efficacy of chondroitin sulfate (CS) and glucosamine (GS), the most relevant drugs of "Symptomatic Slow Acting Drug for Osteoarthritis" (SYSADOA), in the functional and symptomatic improvement of temporomandibular dysfunction. Although, controversy exists regarding their benefit.

Methods: An electronic search was conducted to retrieve randomized controlled clinical trials (RCTs). The risk of bias assessment was evaluated using the Cochrane Collaboration's tool. Data were meta-analyzed with a random effect model whenever possible.

Results: Three RCTs were included. Qualitative results showed a decrease in pain, joint noise, and inflammatory biomarkers in synovial fluid and an improvement in maximum mouth opening without significant adverse effects. Meta-analysis showed a significant increase in maximum mouth opening with the use of CS-GS (p = 0.19). No statistically significant differences were found in pain reduction compared to tramadol.

Conclusion: CS-GS is effective and safe in the symptomatic and functional improvement of patients with TMD.

The volcanological community manages heterogeneous types of data acquired during research projects and monitoring activities of volcanoes. These data consist of both continuous and discrete measurements and observations, which are carried out by ground-based networks and remote sensing instruments, or during field surveys and laboratory analyses. Many types of volcanological research are largely based on the accurate sampling of rocks erupted during past and ongoing volcanic activity. Each sample represents a "physical object" which should be identified and archived before part of it is removed for analytical purposes. In this context, we recommend assigning the collected samples unique and persistent identifiers, such as the International Generic Sample Number (IGSN). However, although the IGSN allows recording the most essential information of the collected samples (e.g. geographic location, sampling method, and collector), the predefined metadata fields are not exhaustive for volcanic samples, which require additional information such as type and timing of the eruptive event, sample temperature, and texture. Here we design the guidelines necessary to facilitate communication between and search of multiple sample repositories and databases run by disparate institutions. To this aim, we build a metadata model, which integrate the IGSN metadata with supplementary information necessary for the monitoring and research activities carried out by the volcanological community. The long-term curation of collected materials is an important investment for the future. Indeed, these collections are a resource for the production of volcanological data, they reduce the need for repeated sampling, they preserve samples that can no longer be collected, and they allow repeat analyses to be made. The primary aim of this work, based on discussion within the EUROVOLC project, is to provide the basic information for populating a relational database structure in the future for the description of different volcanic samples, physically located in different physical repositories and institutions, in order to facilitate future sharing between different groups of scientists and more complete volcanological studies, by means of the proposed metadata structure.

Investigating the textural properties and 3D geometry of the connected pore network in volcanic products provides insight into magma ascent processes, due to their influence on magma permeability, outgassing efficiency and explosivity. Here, we used X-ray computed microtomography to investigate vesicle textures in tephra from the 2021 Tajogaite eruption (La Palma, Spain) and the relationship between these pore network parameters and eruptive style. We report a 3D dataset of pore network parameters for lapilli clasts collected throughout the eruption, associated with different eruptive styles (ash-rich jets, lava fountains, Strombolian activity). In clasts from Strombolian activity, the lower vesicle number density (VND) and tortuosity factor (m) suggests that there are fewer vesicles and that the channels which connect them are less tortuous than in clasts from fountain and ash-rich jet activity, favouring a lower degree of gas-melt coupling and thus, more efficient outgassing. Instead, for clasts of lava fountain and ash-rich jet activity, the higher VND and m suggest a higher number of vesicles connected by more tortuous channels, promoting some degree of gas-melt coupling and thus, less efficient outgassing. However, in clasts from ash-rich jets, the presence of narrower channels, as suggested by the lower throat-pore size ratio, favours a greater degree of gas-melt coupling with respect to fountain activity, leading to magma fragmentation. This work highlights the importance of textural and pore network analyses in understanding eruption dynamics, and provides a case study for investigating the interplay between pore network parameters, magma permeability and ascent dynamics for low-viscosity magmas.

Supplementary information: The online version contains supplementary material available at 10.1007/s00445-025-01833-0.

Ruapehu, one of Aotearoa New Zealand's most active andesitic volcanoes, experienced moderate to heightened volcanic unrest beginning March 2022. This included heightened volcanic tremor, the initiation of a new heating phase at the crater lake Te Wai ā-moe, and increases in gas emissions. The unrest featured highly periodic, low-frequency earthquakes known as 'drumbeats'. These signals have been observed around the world to often precede and/or accompany the ascent of magma and volcanic eruptions. However, Ruapehu did not erupt in 2022. In this work, approximately 43,000 discrete drumbeat events and 89 days of continuous volcanic tremor were identified over the 121-day unrest period. These were analysed in the time, amplitude, and frequency domains. We argue that increases in volcanic tremor, lake temperatures, and gas throughput are the result of magma ascent into the shallow system immediately prior to or contemporaneous with the onset of tremor. We construct a conceptual model for the generation of drumbeat, tremor, and lake temperature signals that consists of shallow magma storage, a gas cavity, a permeable cap, and the crater lake. The presence of repetitive drumbeat earthquakes results from transient sealing and failure within the fracture pathways of the permeable cap. This is driven and regulated primarily by pressure accumulation from persistently degassing magma and the strength of the sealing mechanism.

Supplementary information: The online version contains supplementary material available at 10.1007/s00445-025-01823-2.

We collected rapid-repeat radar data capturing the deformation of the active Halema'uma'u summit lava lake surface on January 19, 2023, an otherwise quiescent period during the January-March 2023 eruption. Radar interferograms were generated every 90 s over a 90-min period of intermittent inflation using a scanning real aperture radar operating at Ku-band (17.4 mm wavelength). This technique allows observation of phenomena at a temporal scale and spatial resolution not previously possible. We model the intrusion as a shallow sill, 10 to 100 m below the lava lake surface. We suggest that frequent intrusions of such small volume pulses of gas-rich magma help to provide the flux of heat and mass necessary to compensate for cooling, outgassing, and recycling of dense degassed magma to deeper levels, sustaining the lava lake during periods of near-steady-state.

Supplementary information: The online version contains supplementary material available at 10.1007/s00445-025-01847-8.

As global populations grow, the exposure of communities and infrastructure to volcanic hazards increases every year. Once a volcanic eruption begins, it becomes critical for risk managers to understand the likely evolution and duration of the activity to assess its impact on populations and infrastructure. Here, we report an exponential decay in satellite-derived SO₂ emission rates during the 2021 eruption of Tajogaite, La Palma, Canary Islands, and show that this pattern allows a reliable and consistent forecast of the evolution of the SO₂ emissions after the first third of the total eruption duration. The eruption ended when fluxes dropped to less than 6% of their fitted maximum value, providing a useful benchmark to compare with other eruptions. Using a 1-D numerical magma ascent model, we suggest that the exponentially decreasing SO₂ emission trend was primarily produced by reducing magma chamber pressure as the eruption emptied the feeding reservoir. This work highlights the key role that satellite-derived SO₂ emission data can play in forecasting the evolution of volcanic eruptions and how the use of magma ascent models can inform the driving mechanisms controlling the evolution of the eruption.

Supplementary information: The online version contains supplementary material available at 10.1007/s00445-025-01803-6.

Understanding the processes leading up to caldera-forming eruptions is essential for identifying precursory signals of catastrophic events. While these phenomena have been extensively studied in silicic systems, mafic volcanoes present unique challenges. Indeed, the high eruptive temperatures of mafic magmas might imply short storage in the cold upper crust and, thus, short periods of unrest preceding eruption, which could challenge our capacity to mitigate the impact of an imminent event. In this study, we present new textural data, major- and trace-element analyses, and quantitative trace-element maps of the crystal cargo from an effusive to mildly explosive sequence (the Fontana Centogocce Formation) and the subsequent caldera-forming phase (the Villa Senni Formation) at the Colli Albani volcano in Italy. By integrating well-established and data-driven approaches, we constrain the processes and dynamics that drive the transition from mildly explosive to highly explosive activity in the studied magmatic sequences. Our findings reveal that the effusive to mildly explosive eruptions preceding the caldera-forming event were fed by multiple magma reservoirs emplaced at shallow crustal levels ( $\sim$ 1-4 kbar). Following a quiescent period recorded by a paleosol, more primitive magma rose directly from the mantle and accumulated at multiple crustal levels. The ascent of one of these magma pulses ultimately triggered Colli Albani's last caldera-forming eruption.

When the first transoceanic telegraph cables were laid in the mid-1800s, rapid communication between continents became possible. The advent of fibre-optic submarine cables in the 1990s catalyzed a global digital revolution. Today, a network of > 1.7 million kilometres of fibre-optic cables crosses the oceans, carrying more than 99% of all digital data traffic worldwide and trillions of dollars in financial transactions. These arteries of the global internet underpin many aspects of our daily lives, and are particularly important for remote island communities that rely on submarine cables for telemedicine, e-commerce, and online education. However, these same remote communities are often in seismically and volcanically active regions and can be prone to natural hazards that threaten their critical subsea communication infrastructure. This vulnerability was acutely exposed in January 2022, when the collapse of the eruption plume of Hunga Volcano triggered fast-moving density currents that damaged Tonga's only international submarine cable, cutting off an entire nation from global communications in the midst of a volcanic crisis. Here, we present a new comprehensive analysis of damage to subsea communications cables by volcanic events from around the world, and document their diverse impacts. Examples include (i) severing of the telegraph cable crossing the Sunda Strait by a tsunami triggered by the 1883 Krakatau eruption, Indonesia; (ii) ocean-entering pyroclastic density currents, lahars, and landslides during the 1902 eruptions of Mount Pelée, Martinique, that damaged six telegraph cables; (iii) destruction of a cable landing station on Montserrat by a pyroclastic density current in 1997; (iv) submarine slope failure at Kick 'em Jenny, Grenada, that damaged two fibre-optic cables; (v) complete loss of the telecommunications network due to power outages following the 2000 eruption of Miyake-jima, Japan; and (vi) disruption to subsea cables resulting from the 2021 eruption of La Soufrière, St. Vincent. We find that the causes of damage typically relate to secondary hazards that occur not only at the same time as the eruption climax, but also some time after. There does not appear to be an explosivity intensity threshold for cable-damaging events; however, the extent of damage may be related to the original volcano morphology (e.g. steep slopes), spatial location (e.g. near the coast or partially/totally submerged), the eruption size or explosivity, and/or volcanic depositional processes involved. Based on these diverse case studies, we present lessons learned for enhancing telecommunications resilience, and discuss how subsea cables themselves can be used as sensors to improve understanding and early warning of volcanic hazards, potentially filling a monitoring gap for remote island communities.

Supplementary information: The online version contains supplementary material available at 10.1007/s00445-025-01832-1.

Geysers are natural geothermal features that episodically erupt hot water and steam due to the buildup and release of subsurface vapor bubbles. At Strokkur geyser, Iceland, eruptions begin with the growth of a surface bulge caused by rising bubble clusters, followed by gradual rupture and disintegration into a water fountain. In this study, we investigate the high-resolution acoustic and visual signatures of this initial phase of the eruption, providing detailed insights into the fluid dynamics that govern bulge formation and rupture. While similar eruptive behavior is sometimes observed in low-viscosity volcanic systems, Strokkur offers a uniquely transparent medium in which processes like bubble rise and clustering can be directly observed, providing analogies to otherwise obscured dynamics in lava or mud-dominated settings. We combine low-frequency infrasound and high-frequency audio recordings with high-speed video, using synchronized data to track the evolution of the bulge. The results demonstrate that infrasound effectively detects bulge growth, while the onset of rupture is marked by a rise in audio-frequency amplitude. A monopole model is used to simulate pressure variations during bulge growth. The observed decompression signal is associated with the downward water motion during bulge disintegration. These findings improve our understanding of geyser eruption dynamics and suggest how acoustic monitoring can provide valuable information about subsurface processes in both geysers and volcanoes, such as dome inflation or gas bubble accumulation beneath magma surfaces.

Supplementary information: The online version contains supplementary material available at 10.1007/s00445-025-01876-3.