Volcanic Risk Research Articles

How long-term hazard assessment may help to anticipate volcanic eruptions: The case of La Palma eruption 2021 (Canary Islands)

Long-term hazard assessment is an essential action that should be undertaken at all active volcanoes and/or volcanic areas as an indispensable contribution to reduce volcanic risk. It allows anticipating new eruptions responding to two of the main questions of volcano forecasting: where and how the next eruption will be. In the case of the Canary Islands, an active volcanic region that receives millions of visitors every year, and which has been recently severely impacted by a small size eruption on the island of La Palma in 2021, a systematic long-term hazard assessment is still pending, despite this being foreseen in its management plan to face volcanic threats. An essential basic long-term volcanic hazard assessment, conducted six years before this last eruption, was able to anticipate the location of the new vents and the eruptive style, including the extent of its main potential hazards. This long-term research was developed in the frame of a Master thesis, which was aimed at justifying the viability of a particular systematic long-term volcanic assessment methodology to be applied to the Canary Islands and elsewhere. Despite this particular study was not used to manage the La Palma 2021 eruption, it demonstrates how beneficial such studies may be to forecast new eruptions and to reduce their associated risk, and represents a new contribution to develop adequate territorial and management planning where we provide a qualitative hazard map for the Island of La Palma.

Volcano Monitoring With Magnetic Measurements: A Simulation of Eruptions at Axial Seamount, Kīlauea, Bárðarbunga, and Mount Saint Helens

AbstractMonitoring of active volcanic systems is a challenging task due in part to the trade‐offs between collection of high‐quality data from multiple techniques and the high costs of acquiring such data. Here we show that magnetic data can be used to monitor volcanoes by producing similar data to gravimetric techniques at significantly lower cost. The premise of this technique is that magma and wall rock above the Curie temperature are magnetically “transparent,” but not stationary within the crust. Subsurface movements of magma can affect the crustal magnetic field measured at the surface. We construct highly simplified magnetic models of four volcanic systems: Mount Saint Helens (1980), Axial Seamount (2015–2020), Kīlauea (2018), and Bárðarbunga (2014). In all cases, observed or inferred changes to the magmatic system would have been detectable by modern magnetometers. Magnetic monitoring could become common practice at many volcanoes, particularly in developing nations with high volcanic risk.

Geochemical and Sr-Isotopic Study of Clinopyroxenes from Somma-Vesuvius Lavas: Inferences for Magmatic Processes and Eruptive Behavior

Somma-Vesuvius is one of the most dangerous active Italian volcanoes, due to the explosive character of its activity and because it is surrounded by an intensely urbanized area. For mitigating the volcanic risks, it is important to define how the Somma-Vesuvius magmatic system worked during the past activity and what processes took place. A continuous coring borehole drilled at Camaldoli della Torre, along the southern slopes of Somma-Vesuvius, allowed reconstructing its volcanic and magmatic history in a previous study. In this work, the wide range of chemical (Mg# = 92–69) and isotopic (87Sr/86Sr = 0.70781–0.70681) compositions, collected on single clinopyroxene crystals separated from selected lava flow units of the Camaldoli della Torre sequence, have been integrated with the already available bulk geochemical and Sr-isotopic data. The detected chemical and isotopic signatures and their variation through time allow us to better constrain the behavior of the volcano magmatic feeding system, highlighting that mixing and/or assimilation processes occurred before a significant change in the eruptive dynamics at Somma-Vesuvius during a period of polycyclic caldera formation, starting with the Pomici di Base Plinian eruption (ca. 22 ka).

Lava deltas, a key landform in oceanic volcanic islands: El Hierro, Canary Islands

Marine and subaerial erosion of volcanic ocean islands form coastal cliffs and shore platforms, particularly during stable sea levels. Posterosional lava flows can spill over these coastal cliffs and fill the platforms, leading to the progradation of lava deltas. This work aims to analyze this volcanic rocky coast setting at the island scale and to assess the volcanic constructional and erosive degradational effects on the coast at the scale of one volcanic edifice. El Hierro Island, Canary Islands, exemplifies a rocky coast with an active sea-cliff profile, reflecting its early evolutionary stage as a young ocean volcanic island with no fringing reef. The occurrence of a contemporary insular shelf formed during the Holocene sea-level highstand (<7 ka) allows constraining the ages of those eruptions forming lava deltas affecting this geomorphological landform. A detailed bathymetry around the island allowed us to distinguish 17 eruptions fulfilling this criterion. The Montaña del Tesoro, which occurred about 1050 years BP, is one of these eruptions and was selected as a case study for morphometric modeling integrating subaerial and submarine data at the scale of a volcanic edifice. This eruption was a Strombolian basaltic volcanic event that produced a scoria cone, pyroclastic fall deposits, and lava flows that reached the ocean in the eastern rift zone of El Hierro island. We combine field-based observations with topographic and bathymetric data analysis to reconstruct the pre- and post-eruption Digital Elevation Models (DEMs) and, comparing with present-day DEM, to analyze morphometrically the influence of volcanism on the coastal landscape's development. The resulting landform complexity required the discretization of the lava field according to the coastline evolution and lava front sectors, and the subaerial or submarine lava placement. The pyroclastic materials' total erupted bulk volume (12,829,578 m3) corresponds to a volcanic eruption index (VEI) of 3. This event was primarily effusive. From a dense rock equivalent (DRE) volume of 25,615,424 m3, 87 % flowed as lava, 10 % formed the cinder cone, and 3 % the tephra fall deposits. We quantitatively demonstrate that dominant degradation occurs in the lava field, mainly disturbed by marine erosion. Marine erosion removed 9 % of the erupted volume of lava flows against 1 % by fluvial erosion. This work provides methods and results of great interest with different implications in oceanic volcanic islands, among which we can mention coastal planning (e.g., rock coast evolution) and volcanic risk assessment (e.g., the importance of Holocene sea-level rise on the development of shore platforms facilitating the progradation of lava deltas).

Challenges and Opportunities for Risk Management of Volcanic Hazards in Small-Island Developing States

The explosive volcanic eruptions of La Soufrière volcano, St Vincent and the Grenadines, in April 2021 caused the displacement of thousands of people, resulting in heavy disruption of livelihoods and economic activities, destruction of critical infrastructure, and volcanic ash deposits that affected the entire mountainous island of St Vincent and the neighboring island of Barbados. The resulting triple crisis in the region included volcanological risks, the prevailing COVID-19 pandemic, and hydrometeorological risks due to the approaching hurricane season. This article analyzes the scientific and operational activities that The University of the West Indies Seismic Research Centre undertook after effusive activity was detected in December 2020, as well as the actions taken during an official response mission of the United Nations, led by the Joint Environment Unit of the United Nations Environment Programme and the United Nations Office for the Coordination of Humanitarian Affairs in Geneva and upon request for international environmental assistance from the Government of St Vincent. It examines the interplay and collaboration between these 2 organizations and other disaster risk reduction agencies. The article also highlights how the interconnected, systemic nature of risks and disasters emphasizes the ultimate need for regional coordination and collaboration across sectors, including scientific monitoring networks; national, regional, and international emergency preparedness and response agencies; academia; and the private sector. The presented case study for elucidating the ongoing lahar hazard at La Soufrière volcano supports a long-term view for planning and mitigation in this challenging topography. This will help to ensure that the volcanic risks in the Caribbean region are appropriately considered a major component of the multihazard approach undertaken by national authorities and scientists to manage community safety and sustainable economic development through adequate means of disaster risk reduction and emergency preparedness.

Improved retrieval of SO2 plume height from TROPOMI using an iterative Covariance-Based Retrieval Algorithm

Abstract. Knowledge of sulfur dioxide layer height (SO2 LH) is important to understand volcanic eruption processes, the climate impact of SO2 emissions and to mitigate volcanic risk for civil aviation. However, the estimation of SO2 LH from ground-based instruments is challenging in particular for rapidly evolving and sustained eruptions. Satellite wide-swath nadir observations have the advantage to cover large-scale plumes and the potential to provide key information on SO2 LH. In the ultraviolet, SO2 LH retrievals leverage the fact that, for large SO2 columns, the light path and its associated air mass factor (AMF) depends on the SO2 absorption (and therefore on the vertical distribution of SO2), and SO2 LH information can be obtained from the analysis of measured back-scattered radiances coupled with radiative transfer simulations. However, existing algorithms are mainly sensitive to SO2 LH for SO2 vertical columns of at least 20 DU. Here we develop a new SO2 LH algorithm and apply it to observations from the high-spatial-resolution TROPOspheric Monitoring Instrument (TROPOMI). It is based on an SO2 optical depth look-up table and an iterative approach. The strength of this scheme lies in the fact that it is a Covariance-Based Retrieval Algorithm (COBRA; Theys et al., 2021). This means that the SO2-free contribution of the measured optical depth is treated in an optimal way, resulting in an improvement of the SO2 LH sensitivity to SO2 columns as low as 5 DU, with a precision better than 2 km. We demonstrate the value of this new data through a number of examples and comparison with satellite plume height estimates (from IASI and CALIOP), and back-trajectory analyses. The comparisons indicate an SO2 LH accuracy of 1–2 km, except for some difficult observation conditions, in particular for optically thick ash plumes or partially SO2-filled scenes.

Classification of seismic activity at the Lazufre Volcanic System, based on 2011 to 2012 data

The Lazufre Volcanic System (LVS), on the border of northern Chile and Argentina, is an active complex of two volcanoes, Lastarria to the north and Cordón del Azufre to the south. The LVS is not regularly monitored with any scientific equipment despite being recognized as a top ten volcanic hazard in Argentina by the Observatorio Argentino de Vigilancia Volcánica of the Servicio Geológico y Minero Argentino. The system has shown unusual inflation signatures observed in InSAR but the level of seismic activity and its spatial and temporal distribution were unknown due to the lack of a permanent local seismic network. The PLUTONS Project deployed eight broadband seismic stations throughout the LVS between November 2011 and March 2013. This study shows event locations and types from November 2011 through March 2012. We analyze 591 seismic events within 20 km of Lastarria. Most events cluster tightly beneath Lastarria and almost no activity is observed beneath Cordón del Azufre or the primary inflation center. All events are reviewed manually, and located using a velocity model that assimilates prior studies and accounts for hypocenters within the edifice up to 5 km above sea level. More than 90% of the resulting hypocenters are shallower than 10 km below sea level. The waveforms have characteristics similar to those observed at many other volcanoes, suggesting five classes of events: volcano-tectonic (VT), long-period 1 (LP1), long period 2 (LP2), hybrid (HY), and unknown (X). Frequency-magnitude analysis reveals distinct b-values ranging from 1.2 for VT events to 2.5 for LP1 events. Based on the spatial distribution of events and the b-values, we infer that seismic activity is driven mainly by movement of fluids and gases associated with the regional magma zones and inflation centers. The seismic activity is energetic at times, and quieter at others, suggesting the presence of episodic magmatic and/or hydrothermal activity, focused at Lastarria. Our findings indicate that the previously observed inflation signals are indeed volcanic in origin. These results also demonstrate the potential for success of a future seismic monitoring system and provide a framework for interpreting the subsequent observations, both of which are critical to assessing the volcanic risk of the northern Chile-Argentina region.

A GIS-Based Hydrogeological Approach to the Assessment of the Groundwater Circulation in the Ischia Volcanic Island (Italy)

Assessing the variations in space and time of groundwater circulation in volcanic islands is of paramount importance to the description of the hydro-geo-thermal system and implementation of hydrogeological, geochemical, and volcanic monitoring systems. In fact, the reliable reconstruction of the groundwater potentiometric surface in such composite volcanic aquifer systems can enable the identification of the most advantageous strategies for both the sustainable use of groundwater resources and the management of volcanic risk. Geographical Information System (GIS) platforms can support the integration and analysis of many spatial and temporal variables derived from monitoring of active volcanoes and the elaboration of spatially continuous data. However, open issues still affect the reliability and general applicability of common spatial interpolation methods in the case of groundwater potentiometric surfaces. This is related to the assessment of the main stratigraphic and volcano-tectonic features affecting the hydraulic head changes. With regard to the dynamically very active Ischia Island (Italy), this study illustrates a GIS-based hydrogeological approach to identify the most accurate interpolation method for mapping the potentiometric surface in complex hydrogeological terrains. The proposed approach has been applied to the existing dataset (1977–2003) stored by Istituto Nazionale di Geofisica e Vulcanologia. Based on a careful geological and hydrogeological survey, a total of 267 wells, from 5 to 250 m in depth, were processed. The data pre-processing involved four meteorological time-series data (1922–1997) and six long records of piezometric water levels (1930–1994). As a result, knowledge of the delineation of rather homogeneous stratigraphic and volcano-tectonic structures at the basin-scale has improved. Thus, new, more reliable potentiometric surfaces of the four main geothermal areas closest to the coast were produced during both dry and wet seasons. The reliability of the processed potentiometric surface was then validated by comparing the spatially continuous data with complementary field data. These findings point toward an optimal interpolation approach for representing the seasonal and areal distribution of main hydrogeological parameters in complex aquifer systems. Finally, insights into variations of hydrological behavior at an active volcanic area will foster an understanding of possible involvement of fresh and thermal waters in triggering phreatic explosions.

Intergenerational transmission of historical memory of volcanic risk in Mexico

Collective memory is built on concepts and meanings that a population shares and builds over time. These contents are perpetuated through oral transmission from generation to generation. In the case of populations exposed to volcanic risk, coexistence with the volcano is part of their history and daily life. The present study focuses on understanding the meanings, perceptions, and responses facing (before and after) volcanic crises. All these are taken from the collective memory that has been transmitted intergenerationally after the new stage of activity of the Popocatepetl volcano in 1994. It was carried out with qualitative methodology, based on symbolic interactionism, integrating elements of ethnography and grounded theory. People of different age groups from a Mexican community near the Popocatepetl volcano participated. The techniques used were in-depth interviews, focus groups, and participant observation. The historical memory of the volcano’s activity before and after the last reactivation was reconstructed, thus evidencing the generational processes.

An Inside Sun: Lickanantay Volcanology in the Salar de Atacama

The need of establishing more substantive dialogs between the mainstream and Indigenous knowledge on volcanoes has been increasingly recognized. To contribute to this endeavor, in this article we present the basic volcanological understandings of the Lickanantay people in the Salar de Atacama Basin. The Salar de Atacama Basin is an active volcanic territory within the Central Volcanic Zone of the Andes (CVZA). From the El Tatio geothermal field to Socompa volcano, more than 19 active volcanoes surround the territory that the Lickanantay (Atacameño) people have inhabited for more than 11,000 years. Living around and with the geological dynamism of the CVZA for millennia, the Lickanantay communities have accumulated rich observational and ceremonial data on volcanoes and volcanism. Paradoxically, however, while the Atacameño people have thoroughly characterized the CVZA, the volcanology community has not been properly introduced to the ancestral knowledge articulated in the territory. In order to make traditional Atacameño perspectives on volcanoes, volcanic risk, and geo-cosmic interdependence more amply available to the volcanology community, in this article, we present a basic description of what we call Atacameño volcanology. By Atacameño volcanology, we understand the ancestral principles by which volcanoes are known and understood as partaking in larger processes of a cosmo-ecological formation. Specifically, we describe the basic volcanological notions arising from the Lickanantay ancestral knowledge—volcanic formation, functions, and behavior. Second, we focus on the El Tatio geothermal field to offer a situated example. Finally, we delineate some relevant elements of human–volcano interactions and volcanic risk management from an Atacameño perspective. In our conclusions we suggest that volcanology, particularly in the context of the Andes, needs to engage more substantially with the Atacameño or other ancestral systems of knowledge production to expand volcanological insights and respond to the call for decolonizing science.

Implication of Mutual Assistance Evacuation Model to Reduce the Volcanic Risk for Vulnerable Society: Insight from Mount Merapi, Indonesia

The successful evacuation of vulnerable people during emergencies is a significant challenge. In the case of a Mount Merapi eruption, limited private vehicles in the community and a lack of evacuation transport and government volunteers led some people to walk to the meeting area. Consequently, low walking speeds by vulnerable persons may increase the risk and delay. Therefore, the mutual assistance strategy is proposed to support vulnerable people by evacuating them with young people. This grouping was simulated using an AnyLogic software with the agent-based model concept. Pedestrians and vehicles played the roles of significant agents in this experiment. Evacuation departure rate, actual walking speed, group size, route, and coordination were crucial agent parameters. Human behavior and agent distribution were investigated using stakeholders and local community interviews. We measured the walking speed directly to find the independent and group speed. Afterward, we developed three scenarios and models for the evacuation process. A traffic approach was used in the simulation. The results revealed that this mutual assistance model is effective for the rapid evacuation and risk reduction of vulnerable communities where successful evacuation rates have improved. The highest arrival rating was obtained by the Model 3, which was assembled and well-coordinated from home. These findings are a novelty in the volcano context and reflect all categories of vulnerable behavior involving the elderly, disabled, children, and pregnant mothers. The model will benefit disaster management studies and authorities’ policies for sustainable evacuation planning and aging population mitigation.

Multisource and temporal thermal infrared remote sensing of Hasandağ Stratovolcano (Central Anatolia, Turkey)

Hasandağ is a double-peaked long-dormant volcano, where associated volcanic risk is poorly known and needs to be assessed. Weak fumaroles and water vapor emissions have been observed at several vents, on the western flank of the Greater Hasandağ summit, between 3000 and 3100 m (a.s.l.). The highest temperature and CO2 values measured in those vents were ~ 70 °C and > 100,000 ppm respectively. Multisource and wide-period thermal remote sensing analyses were performed to investigate the thermal state and to test the possibilities of remote thermal monitoring of the volcano.MODIS daily surface temperature data were analyzed for a period of 18 years. We used a statistical approach using the Seasonal Decomposition of Time-series procedure to decompose the temperature data into the trend, seasonal, and remainder components. The trend component was used to analyze temporal thermal anomalies in comparison to the decomposed meteorological temperature data. 56 nighttime ASTER TIR imagery acquired between 2001 and 2018 had been used to derive and analyze the Surface temperature, Surface temperature anomaly and Relative radiative heat flux. High-resolution ground-based and aerial thermal mosaic images were built to investigate the thermal radiation over the summit fumarole zone and its structural dependence.A baseline reference value for thermal monitoring of the fumarole zone was achieved using remotely sensed data and time-series decomposition of long-term TIR data. The resolution of the thermal imagery positively affects the mapping and monitoring capability. A permanent ground-based thermal observation station should be established for direct and remote thermal monitoring of the fumarole zone.

Translating research into operational procedures for reducing the risk from volcanic eruptions

In this perspective piece, we reflect on scientific progress in volcanic risk reduction and its prospects for future development. In spite of recent advances, a dichotomy still exists between the products of academic research and the desire for practical applications. The main themes to emerge are (1) the need to find the most effective ways to explain the ever growing amount and complexity of volcanological data to non-specialist stakeholders, and (2) how to transfer to future generations of applied scientists the lessons from practical experience that are often missed by theoretical guidelines. Recommendations for sustaining progress in these fields include improving the accessibility of knowledge and data, embracing novel tools to communicate volcanic risk and uncertainty for decision making, and investing effort on transferring practical experience across generations.En este breve artículo, reflexionamos sobre los adelantos científicos para la reducción del riesgo de erupciones volcánicas y en las oportunidades para continuar progresando. A pesar de avances recientes, todavía existe un desfase entre los resultados de investigaciones científicas y su aplicación práctica. Los temas clave que identificamos son (1) la necesidad de encontrar maneras más efectivas de explicar la cantidad incremental de información volcanológica (y su creciente complejidad) a todos los grupos interesados, especialmente los no-especialistas y (2) cómo transmitir y transferir, a futuras generaciones de cientificos, la experiencia y los aprendizajes prácticos que no figuran en directrices y manuales. Recomendaciones para mantener avances en estos campos incluyen: mejorar la accesibilidad de la información y datos científicos, adoptar nuevas técnicas para comunicar: el riesgo volcánico, la incertidumbre en información científica y para apoyar la toma de decisiones, e invertir en transferir experiencia práctica a las generaciones futuras.

A modular framework for the development of multi-hazard, multi-phase volcanic eruption scenario suites

Understanding future volcanic eruptions and their potential impact is a critical component of disaster risk reduction, and necessitates the production of salient, robust hazard information for decision-makers and end-users. Volcanic eruptions are inherently multi-phase, multi-hazard events, and the uncertainty and complexity surrounding potential future hazard behaviour is exceedingly hard to communicate to decision-makers. Volcanic eruption scenarios are recognised to be an effective knowledge-sharing mechanism between scientists and practitioners, and recent hybrid scenario suites partially address the limitations surrounding the traditional deterministic scenario approach. Despite advances in scenario suite development, there is still a gap in the international knowledge base concerning the synthesis of multi-phase, multi-hazard volcano science and end-user needs. In this study we present a new modular framework for the development of complex, long-duration, multi-phase, multi-hazard volcanic eruption scenario suites. The framework was developed in collaboration with volcanic risk management agencies and researchers in Aotearoa-New Zealand, and is applied to Taranaki Mounga volcano, an area of high volcanic risk. This collaborative process aimed to meet end-user requirements, as well as the need for scientific rigour. This new scenario framework development process could be applied at other volcanic settings to produce robust, credible and relevant scenario suites that are demonstrative of the complex, varying-duration and multi-hazard nature of volcanic eruptions. In addressing this gap, the value of volcanic scenario development is enhanced by advancing multi-hazard assessment capabilities and cross-sector collaboration between scientists and practitioners for disaster risk reduction planning.

Data assimilation of volcanic aerosol observations using FALL3D+PDAF

Abstract. Modelling atmospheric dispersal of volcanic ash and aerosols is becoming increasingly valuable for assessing the potential impacts of explosive volcanic eruptions on buildings, air quality, and aviation. Management of volcanic risk and reduction of aviation impacts can strongly benefit from quantitative forecasting of volcanic ash. However, an accurate prediction of volcanic aerosol concentrations using numerical modelling relies on proper estimations of multiple model parameters which are prone to errors. Uncertainties in key parameters such as eruption column height and physical properties of particles or meteorological fields represent a major source of error affecting the forecast quality. The availability of near-real-time geostationary satellite observations with high spatial and temporal resolutions provides the opportunity to improve forecasts in an operational context by incorporating observations into numerical models. Specifically, ensemble-based filters aim at converting a prior ensemble of system states into an analysis ensemble by assimilating a set of noisy observations. Previous studies dealing with volcanic ash transport have demonstrated that a significant improvement of forecast skill can be achieved by this approach. In this work, we present a new implementation of an ensemble-based data assimilation (DA) method coupling the FALL3D dispersal model and the Parallel Data Assimilation Framework (PDAF). The FALL3D+PDAF system runs in parallel, supports online-coupled DA, and can be efficiently integrated into operational workflows by exploiting high-performance computing (HPC) resources. Two numerical experiments are considered: (i) a twin experiment using an incomplete dataset of synthetic observations of volcanic ash and (ii) an experiment based on the 2019 Raikoke eruption using real observations of SO2 mass loading. An ensemble-based Kalman filtering technique based on the local ensemble transform Kalman filter (LETKF) is used to assimilate satellite-retrieved data of column mass loading. We show that this procedure may lead to nonphysical solutions and, consequently, conclude that LETKF is not the best approach for the assimilation of volcanic aerosols. However, we find that a truncated state constructed from the LETKF solution approaches the real solution after a few assimilation cycles, yielding a dramatic improvement of forecast quality when compared to simulations without assimilation.

A quantitative approach to the 2014 Mt. Ontake volcanic eruption news coverage: understanding the information gap and the public response to the anniversary coverage

This paper studies the news coverage of the 2014 Mt. Ontake eruption disaster from 2015 to 2019, and the public response to the fifth anniversary coverage. Information on the issues regarding the risk of low-frequency disaster events such as volcanic eruption is brought into the public largely through the media. Unless there is a volcano nearby, there are few opportunities to discuss volcanic disaster prevention, and enhance volcanic risk perception. Therefore, the media agendas on volcanic risk are an indicator of what people know about volcanic disaster preparedness. This study quantitatively analyzed the 2014 Mt. Ontake eruption reports of national, regional, and local newspapers to reveal their topic distributions. In addition, the anniversary gained intense public attention due to the large amount of media coverage. It was a significant opportunity for society to discuss volcanic risk. By observing people’s online responses to the anniversary coverage, a trend could be identified. We found a significant difference in media attention among the three newspaper types. The local newspaper covered four topics relating to volcanic risk in a well-balanced way, but the national and regional newspapers paid greater attention to one or two topics. Many online comments presented the view that a mountaineering should be done at individuals’ own risk, and volcano shelters would be ineffective for averting volcanic disasters. The anniversary coverage unintentionally contributes to stigmatizing or scapegoating a certain group, rather than promoting risk communication in the public sphere on the Web. With the onset of the information and communication information technology era, an online dialogue regarding disaster awareness and prevention is important. A volcano disaster risk communication strategy on the Web should be developed.

Anomalous Behavior of Zirconium and Hafnium in Volcanic Fumarolic Fluids

AbstractThe Zirconium and Hafnium concentrations in worldwide fumaroles fed by magmatic fluids reveal that the Zr/Hf ratio is inversely related to the temperature of emission. Lower Zr/Hf ratio values below the chondritic signature are found in fluids having the highest temperature while super‐chondritic Zr/Hf ratio values are found in lower temperatures. Sub‐chondritic values of the Zr/Hf ratio may be related to larger volatility of Hf‐chloride gas species with respect to Zr‐Cl gas species, while super‐chondritic ratios may correspond to fluid‐rock processes resulting from cooling of uprising magmatic fluids. We propose that sub‐chondritic Zr/Hf ratio values in fumaroles associated with high temperature may be an appropriate marker of fast magmatic rising representing a new sensitive tool for volcanic risks strategies.

Eruption cycles of Mount Etna triggered by seasonal climatic rainfall

The ability to mitigate and predict volcanic risk is a long-standing question in the Geosciences’ community, while the extent of volcanic activity may be regulated by a predictable and periodic external excitation induced by seasonal rainfall, hydrological loading, or Moon-Sun gravitational force. Moreover, the complex stress-triggering, hydro-mechanical coupling in response to seasonal rainfall, and associated feedback mechanism with deep magmatic process remains enigmatic and indeed deserves more attention in view of recent climate change scenario. In this letter, a compelling scenario of seasonal rainfall-triggered eruption cycles of Mount Etna (Italy) is found and presented on the eastern coast of Sicily which continuously erupting since last 200 kyr. Results show that the seasonal rainfall significantly weakened the Mount Etna edifice and initiated mechanical tensile failure in the complex magmatic plumbing system and adjacent flank surface by changing the pore pressure build-up, probably promoting dyke intrusion and eventual triggering of eruptive cycle. Further, the possibility of seasonal hydrological loading on the Mount Etna volcano and adjacent flank region, hydrological load-induced sliding along the impermeable outer ‘shell’ of the flank are discussed, and the effect of tidal stress perturbations on the eruptions cycle cannot be ruled out completely.

Reviewing volcano hazard and risk communications in Ecuador: experiences from a fast-format workshop

Hazard and risk communication requires the design and dissemination of clear messages that enhance people’s actions before, during, and after volcanic crises. To create effective messages, the communication components such as message format and content, must be considered. Changes in technology are changing the way people communicate at an ever-increasing pace; thus, we propose revising the basic components of the communication process to improve the dialogue between scientists and the public. We describe communication issues during and outside volcanic crises in Ecuador and assess possible causes and consequences. These ideas were discussed during the short-duration “Volcano Geophysical Principles and Hazards Communications” Workshop in Baños, Ecuador in 2019. We review and propose communication strategies for volcanic hazards and risks that resulted from the workshop discussions and experiences of experts from the Instituto Geofísico (IG-EPN), local and international professors involved in volcano research and communication, and students from universities across Ecuador.

Tephrostratigraphy of proximal pyroclastic sequences at Mount Melbourne (northern Victoria Land, Antarctica): Insights into the volcanic activity since the last glacial period

We report on the characterization of a thick sequence of pyroclastic deposits exposed on the summit area and flanks of Mount Melbourne volcano, in northern Victoria Land, Antarctica related to eruptions during the Late Glacial period. We provide a complete characterization of tephra deposits including mineralogy, single shard major- and trace-element glass compositions, and an 40Ar-39Ar age of feldspar crystals extracted from the deposit. The pyroclastic deposits are trachybasaltic to trachytic in composition and are interpreted to have resulted from four Strombolian/Vulcanian to sub-Plinian/Plinian eruptions. The younger and more intense sub-Plinian/Plinian eruption (our eruption 2) yielded an 40Ar-39Ar age of 13.5 ± 4.3 ka (±2σ). The study of Mount Melbourne proximal deposits provides significant new data for the reconstruction of the volcano eruptive history and a better assessment of the volcanic risk connected to a possible future eruption.We also explore geochemical correlations between Mount Melbourne proximal deposits and distal tephra layers recognized in ice cores and blue ice fields of East Antarctica. A good geochemical match exists between the composition of products from the trachytic sub-Plinian/Plinian eruption 2 and some tephra layers from Talos Dome and shards in Siple Dome which is also compatible in age (c. 9.3 ka) with our 40Ar-39Ar age determination. Our new insights into the volcanic history of Mount Melbourne and the new high-quality electron microprobe and trace element composition data on its proximal products will help improve future correlations and synchronization of tephra archives in the region.