Active Volcanoes Research Articles

Development of STEAM teaching materials for understanding volcano disaster prevention systems

Education around volcanic activity and volcanic disaster prevention systems is important in Japan due to its proximity to the Ring of Fire where there are hundreds of active volcanoes. Knowledge and awareness of what to do during volcanic eruptions has the potential to save lives. The science of predicting volcanic eruptions is complex and it is therefore difficult to predict eruptions. Therefore, comprehensive knowledge is crucial to ensure effective disaster mitigation strategies are in place. Dr Shintaro Sato, Faculty of Contemporary Human Studies, Kyoto Notre Dame Women’s University, Japan, leads a team of researchers that is developing STEAM (science, technology, engineering, the arts and maths) teaching materials. The goal is to improve understanding of volcano disaster prevention systems among students and the wider community. This means correctly recognising disaster information provided by the Japan Meterological Agency and other organisations, and using this information to select actions and make decisions in the event of a disaster. This includes understanding of volcanic observation systems, the reading of numerical data obtained and knowledge of natural phenomena related to volcanic eruptions. In doing so, Sato believes the content is more likely to have a positive impact on peoples’ lives. Following the development of the teaching materials, the researchers investigated the effectiveness of the content, in part by comparing the functions of MESH blocks. These include motion, motion-sensing, temperature and humidity, button and LED blocks.

THE ROLE OF MUD VOLCANOES IN THE FORMATION OF OIL AND GAS STRUCTURES OF THE SOUTHERN CASPIAN BASIN

The research work considered the issue of the formation of oil and gas structures of mud volcanoes, and also analyzed the geological structure of the South Caspian Basin. In addition, the presented article characterized the South Caspian depression as being covered by a sedimentary cover with a thickness of more than 30 km, along with the widespread manifestation of mud volcanism. Therefore, the issue of studying the area, taking into account the regularity of the distribution, number and activity of mud volcanoes within the framework of the research, is considered relevant. Based on the research conducted, it should be noted that the movement of plates moving horizontally and vertically and mud volcanism form the morphological structure of the seabed. The activity of volcanoes in marine conditions leads to the formation of some relief forms. It should be noted that mud volcanoes are considered to be one of the factors that played a major role in the history of the geological development of the Caspian Sea. Underwater and island-type mud volcanoes located in the sea, like volcanoes located on land, are attributed to transverse and longitudinal faults and are located in different parts of anticlinal uplifts. The article provides a general analysis of mud volcanoes, both on land and at sea, and as a result, the geological characteristics of the eruption products, geochemical properties, as well as the differences and similarities between the morphologies of the volcanoes were determined. Keywords: South Caspian Depression, mud volcanoes, seismicity, eruption products.

New palaeolimnological record from West Anatolia (Paleo‐Kuleönü Lake) provides new information on the activity of the Gölcük volcanism and the distribution of the Santorini Minoan eruption

AbstractAnatolia, which had active volcanoes during the Pleistocene and Holocene periods, was also influenced by volcanic eruptions around the Eastern Mediterranean. Therefore, tephrochronology is an important research topic in palaeoenvironmental studies conducted in Anatolia. This study focuses on the geochemical characteristics, chronologies and source areas of six different tephra layers identified in a 16 m sediment core obtained from Paleo‐Kuleönü Lake in the Lake District of West Anatolia. Whole‐rock geochemistry is used to determine the geochemical characteristics and source of the tephra layers, micro X‐ray fluorescence analysis is used to determine relative element changes throughout the cores, and 14C analysis is performed to establish the chronologies. The geochemistry of the Paleo‐Kuleönü Lake tephra layers is consistent with the Gölcük volcanism located in West Anatolia province and the Minoan eruption within the Aegean volcanic province. The layers that resemble the geochemistry of the Gölcük volcanism accumulated at ~33 218 cal a bp (PLK‐19‐1; 30 cm), ~32 267 cal a bp (PLK‐19‐2: 18 cm), ~31 597 cal a bp (PLK‐19‐3; 8 cm), ~31 300 cal a bp (PLK‐19‐4; 17 cm) and ~26547 cal a bp (PLK‐19‐5; 13 cm) and are associated with the last eruptive cycle (Cycle III) of the volcanism. The closest tephra layer to the surface in the sediment core, designated as PLK‐19‐6 (~1.5 cm), shows geochemical similarities with the Santorini Minoan eruption. However, according to our data, the age of the tephra layer is ~4717 bp/~5542 cal a bp, which is inconsistent with the widely accepted date for the Minoan eruption in the literature. The discrepancy between the geochemical match and chronological inconsistency is discussed in the context of the results presented in the paper.

Magmatic evolution of the Kikai caldera revealed by zircon triple dating and its chemistry

Reconstructing the volcanic history of the Kikai caldera, a large active volcano that produced a ~ 160 km3 eruption at 7.3 ka off the southern coast of Kyushu Island (southwest Japan), is crucial to assess potential future volcanic hazards at both regional and global scales. However, revealing its volcanic history before the 7.3 ka eruption has been challenging due to the caldera being mostly submerged. In this study, we present evidence that the Kikai caldera erupted a geochemically distinct silicic lava at ~ 250 ka by using zircon triple (U-Pb, Th-Pb, U-Th) dating and its chemistry. The presence of 1.5–1.0 Ma zircons in the 7.3 ka eruption deposits suggests that zircon crystallization in the Kikai caldera began during this period. We further infer large eruptions occurred around 0.7–0.6 Ma, suggesting that the Kikai caldera may have experienced at least 5 major eruptions during its 1.0–1.5-million-year magmatic evolution.

Genomic analysis and potential polyhydroxybutyrate (PHB) production from Bacillus strains isolated from extreme environments in Mexico

BackgroundPlastic pollution is a significant environmental problem caused by its high resistance to degradation. One potential solution is polyhydroxybutyrate (PHB), a microbial biodegradable polymer. Mexico has great uncovered microbial diversity with high potential for biotechnological applications. The best polymer producers tend to be isolated from environments that require survival adaptations from microorganisms, the high-producing Bacillus cereus strain saba.zh comes from refinery wastewater, the costs of production have been a limiting factor for biopolymer production, and one of the focuses of interest has been finding novel strains with better production or singular traits that help in industrial processes.ResultsThe isolates were taxonomically classified as Bacillus cereus MSF4 and Bacillus inaquosorum MSD1 from Mina, Nuevo Leon; B. cereus S07C; and Paenibacillis dendritiformis from the active volcano “El Chichonal” on Chiapas. The strains had growth temperatures ranging from 35 to 50 °C and pH tolerance values ranging from 3 to 9. The best PHB-producing strain, B. cereus MSF4, produced 0.43 g/kg PHB on orange peels, followed by B. inaquosorum MSD1 at 0.40 g/kg, B. cereus S07C at 0.23 g/kg and P. dendritiformis at 0.26 g/kg.ConclusionsThe findings of this study affirm the potential of the Mexican isolated strains as PHB-producing organisms, enabling further studies to test their viability as industrial producers. The ability of P. dendritiformis and B. inaquosorum to synthetize PHB was also confirmed by the observations made providing novel evidence to consider these species as potential producers.

Oscillation frequencies of long-period seismic events at Kusatsu–Shirane volcano, Japan, related to the volume of water vapour in a hydrothermal crack

SUMMARY Long-period (LP) seismic events at active volcanoes are characterized by damped harmonic oscillations, which are thought to be generated by resonances in fluid-filled cracks. LP source properties (crack geometry and fluid properties) are generally estimated by analytically calculating the ratios of spectral peaks in crack resonance frequencies and empirically calculating a quality (Q) factor. However, because this method is applicable only to LP events with more than four spectral peaks, we cannot use it to analyse LP events with fewer spectral peaks. To bridge this gap, we developed a new method to estimate source properties using the frequency (f), Q factor and seismic moment (M0) of the lowest spectral peak of an LP event. We assumed misty gas (water vapour containing small water droplets) as the fluid in the crack and analytically derived the geometrical relationships of the crack. M0 was estimated from observed amplitudes of the lowest spectral peaks at different stations using an assumed crack mechanism. We applied this method to LP events observed from 1989 to 1993 at Kusatsu–Shirane volcano, Japan. We found that the crack length was quite variable, but the crack width was almost constant at around 100 m during our study period. We also found a strong correlation between the inverse of f and the total mass of water in the crack, which can be explained theoretically using the acoustic properties of misty gas and crack geometrical relationships. The total mass of water is proportional to the volume of water vapour in the crack, and the water vapour has been interpreted to be derived from magmatic degassing at depth. The oscillation frequency of the LP event is thus a useful metric for monitoring magma degassing into the shallow hydrothermal system, which is an important constraint on the occurrence of phreatic eruptions. Because our simple approach is widely applicable to LP events, it can enable improved monitoring of hydrothermal activity and evaluation of the risk of phreatic eruptions.

Suitability analysis of the distribution final evacuation sites for Mount Merapi based on GIS

Abstract Mount Merapi is a very active volcano and eruptions often occur on a scale that is difficult to predict, thus endangering people on the slopes of Mount Merapi. FES (Final Evacuation Site) and evacuation routes are one of important things to reduce casualties due to eruptions, therefore its location must be in a safe area or outside the DPA (Disaster Prone Area). The objectives of this research are 1) GIS-based disaster vulnerability class modeling in Mount Merapi area. 2) Analyzing the distribution of FES (Final Evacuation Sites) and determining evacuation routes during the eruption of Mount Merapi based on the hazard class zone. The methods used are buffer analysis to model the DPA class, network analysis to determine the fastest route to the nearest residential evacuation site, and overlay to combine the three. DPA zone modeling is based on BPBD rules. The results obtained are maps of evacuation routes and the suitability of FES to DPA. The distribution of FES on the slopes of Mount Merapi covers the entire study area with two FES that are still very close to Kali Putih.

Lessons learnt from community preparedness for Mount Merapi and Mount Marapi eruption disasters

Mount Merapi, located on the border of Central Java and the Special Region of Yogyakarta, and Mount Marapi in West Sumatra are active volcanoes. Eruption activities will have positive and negative impacts on the surrounding environment. The eruptions of Marapi on December 3, 2023, and Merapi on March 4, 2024, caused severe damage to road infrastructure, buildings, bridges, and settlements and resulted in casualties. This article describes the experiences of communities after the eruption of the two volcanoes. This research uses a combination of literature review and field observation methods to analyze how communities in the Mount Merapi and Mount Marapi areas prepare for disasters. The results of this study show that to increase community resilience to volcanic disasters and flash floods triggered by Mount Merapi and Mount Marapi, collaboration between the government, disaster agencies, and local residents is essential. Measures that can be taken are proactive evacuation protocols, infrastructure development such as sabo dams, and continuous education to increase awareness and preparedness. Recommendations include more intensive cooperation, educational initiatives, and strategic relocation from high-risk zones to effectively protect vulnerable communities.

Melt Flux from the Mantle Regulates the Crustal Processing and δ18O Variations of Kamaʻehuakanaloa Magmas

Abstract Ocean-island basalts display a relatively large range in their oxygen isotopic composition (δ18O) compared to mid-ocean ridge basalts (MORB). The origin of these variations in δ18O—due to a combination of crustal contamination and/or mantle heterogeneity—is controversial. Kamaʻehuakanaloa (formerly Lōʻihi Seamount) is an active submarine Hawaiian pre-shield volcano that is last known to have erupted in 1996. Basalts from Kamaʻehu (for short) are derived from a distinctive 3He-rich deep mantle source within the Hawaiian plume, yet they commonly experience at least two types of shallow crustal contamination based on enrichments in seawater-derived Cl and 234U. Here, we present oxygen isotopic analyses of volcanic glasses (n=102 from 53 samples) and single olivine crystals (n=47 from eight samples) for tholeiitic (n=28), transitional (n=4), and alkalic (n=18) basalts, and three hawaiites from Kamaʻehu. The average δ18O values of both glass and olivine from the North Rift Zone and NE summit platform (~5.6‰ and 5.1‰, respectively) are higher (at >95% confidence) than those from the South Rift Zone and the SW summit platform (~5.3‰ and 4.9‰). The glass alkalic index (AI<0 is the switch from alkalic to tholeiitic lavas as the degree of mantle melting increases) and incompatible element enrichment (K2O/TiO2) increases with decreasing MgO and CaO/Al2O3. The northern Kamaʻehu glasses are more frequently alkalic (~68%), more enriched, and more differentiated than those from southern Kamaʻehu (~81% tholeiitic or transitional). Model eruption ages from 226Ra-230Th disequilibria suggest that the transition from alkalic to tholeiitic volcanism at Kamaʻehu was nearly complete by ~2 ka. The predominantly alkalic northern lavas likely record an earlier phase of the volcano’s eruptive history that has since been covered by the more recent eruptions of tholeiitic basalts to the south. These observations suggest that melt flux from the mantle (recorded by the AI values and K2O/TiO2 ratios) regulates the crustal processing and δ18O variations of Kamaʻehu magmas. The mantle-controlled transition from alkalic to tholeiitic volcanism at Kamaʻehu led to the more frequent supply of larger magma batches produced by higher degrees of mantle melting, establishment of an active shallow hydrothermal system for high-temperature alteration of the volcanic edifice, and a decreasing extent of clinopyroxene fractionation. The average δ18O values of glass (~5.4‰) and olivine (~5.0‰) from Kamaʻehu—similar to the most depleted MORB—represent the best estimate for mantle-derived magma at this volcano. The higher average δ18O values of the glass and olivine from northern Kamaʻehu result from assimilation of volcanic edifice that was altered by seawater-rock interaction at low temperature, whereas the lower δ18O values from southern Kamaʻehu result from assimilation of such materials altered at high temperature.

Toxic natural pollution at Ijen crater volcano: Environmental characteristics and health risk assessment.

The Ijen crater volcano (ICV) is one of the active volcanoes with unique environmental conditions; it is the largest lake in the world with the most extreme acidity and a blue fire phenomenon and releases toxic volcanic gases, including dangerous sulfur dioxide (SO₂). It has an impact on the environment and ecosystem. This research aimed to investigate the blue fire phenomena and toxic gas SO2 and characterize the environmental conditions and health effects of the ICV. The method used in this research involved carrying out an SO2 concentration using an impinger in 32-point sampling around the Inje crater volcano. The environment was characterized based on self-observation, station observation, interviews, and reliable literature data. The health effect was measured based on the threshold level value based on local and global regulations. This research shows that the characteristics of the ICV include a crater lake with a depth of up to 200 m and a diameter of ± 900 m with pH values less than 1. Then, the source of SO2 comes from the reaction of magma with volcanic gas. the blue fire phenomenon, which occurs in certain situations, frequently adds to the natural wonder of the ICV. In addition, the distribution of SO2 concentrations ranges from 480 to 6960 ppb. Next, almost the Hazard Quotion (HQ) > 1 every point sampling. This means that the SO2 concentration and HQ exceed the threshold value affecting human activities.

SEISMICITY of the VOLCANIC AREAS of KAMCHATKA in 2020

The results of near real-time monitoring of the active Kamchatka volcanoes are described. Con tinuous monitoring was carried out using three remote methods: 1) seismic monitoring according to automatic telemetric seismic stations; 2) visual and video observation; 3) satellite observation of the thermal anomalies and the ash clouds. Daily information about volcanic activity is published in the Internet (http://www.emsd.ru/ ~ssl/monitoring/main.htm) since February 2000. The results of analysis of seismic activity of the Northern (Shive luch, Kluchevskoy, Bezymianny, Plosky Tolbachik, Krestovsky and Ushkovsky), Avacha (Avachinsky and Kor yaksky), Mutnovsky-Gorely volcano group and Kizimen, Zhupanovsky, Karymsky and Kambalny volcanoes for 2020 are presented. 3945 earthquakes with KS=1.6–8.6 were located for Northern volcano group, 337 earthquakes with KS=1.6–6.0 – for Avacha volcano group, 498 earthquakes with KS=1.6–6.8 – for Mutnovsky-Gorely volcano group, 55 earthquakes with KS=2.4–7.8 for Kizimen volcano, 41 earthquakes with KS=2.6–7.3 for Zhupanovsky volcano, and 4 earthquakes with KS=5.4–6.6 – for Karymsky volcano. Maps of epicenters, quantities of seismic energy and earthquake distribution according to class are given. All periods of activity were fixed and investigated by remote methods in 2020: an intensive volcanic activity of Sheveluch volcano associated with new cone, the paroxysmal explosive eruption of Bezymianny volcano and the summit explosive-effusive eruptions of Kluchevskoy volcano.

Pembentukan Remaja Sadar Bencana dan Pelatihan Mitigasi Bencana di SMP Muhammadiyah 1 Turi

Mount Merapi, located in Sleman Regency, is one of the most active volcanoes in the world, with eruption intervals ranging from 3 to 7 years. In this community service project, we aim to establish a Disaster-Aware Youth Group and conduct Disaster Mitigation Training at SMP Muhammadiyah 1 Turi. The goal of this community service is to form a group of disaster-aware youth volunteers at SMP Muhammadiyah 1 Turi. The community service method involves disaster preparedness education for 34 students, providing them with both knowledge and practical experience through role-playing and disaster simulation exercises. As a result of this project, a group of disaster-aware youth volunteers has been established at SMP Muhammadiyah 1 Turi. Additionally, posters about disasters and health were created, along with the development of evacuation routes and assembly points. In conclusion, the community service project by the Unisa Yogyakarta lecturers at SMP Muhammadiyah Turi Yogyakarta was successful. The establishment of disaster-aware youth volunteers at SMP Muhammadiyah Turi has been achieved, posters have been installed, and evacuation routes and assembly points have been established. Students' knowledge about disaster preparedness has improved.

Where will the next flank eruption at Etna occur? An updated spatial probabilistic assessment

Abstract. The assessment of the spatial probability of future vent opening is one of the key factors in quantifying volcanic hazard, especially for active volcanoes where eruptions can occur at different locations and altitudes over distributed areas. Mount Etna (Italy), one of the most active volcanoes in the world, exhibits such variability, and its flank eruptions can harm people, properties and services over the volcano's slopes. In this paper, we quantify the spatial probability of future vent opening for Etna's flank eruptions, adopting a kernel analysis and testing different functions (exponential, Cauchy, uniform and Gaussian). Starting from the assumption that the location of past fissures is indicative of where future events will occur, we consider the flank eruptions of the last 4000 years, thus accounting for a much longer and complete record than in previous studies. The large dataset of eruptive fissures enables splitting the data into training and testing subsets. This allows selecting the best kernel model, testing the completeness of the fissure dataset and investigating a possible migration through time in fissure location. The results show that neither under-recording nor possible migration over time significantly affects the informative value of previous flank fissures in forecasting the location of future ones. The resulting map highlights that the most likely opening area follows a northeast-to-south trend, corresponding to the location of the most active rifts. It also shows that the southern flank of the volcano, which is the most urbanized one, sits downhill of the largest cumulated probability area for flank eruption. We also run sensitivity analyses to test the effect of (i) restricting the data to the most recent 400 years and (ii) including the information on the stress induced on the mapped fissures by sources of deformation proposed in the literature for recent eruptions of Etna. The sensitivity analyses confirm the main features of the proposed map and add information on the epistemic uncertainty attached to it.

Geological Disaster Hazard Mapping Based on Geoheritage: A Case Study of the Batur UNESCO Global Geopark

Abstract Batur UNESCO Global Geopark, as the first UNESCO geopark in Indonesia, has been established for 12 years. However, throughout its journey, the area still faces various challenges, particularly in disaster risk reduction efforts. As a geopark focused on active volcanoes, Batur UGGp is not only confronted with the potential hazards of geological disasters such as volcanic eruptions, earthquakes, and landslides but also with the risk of degradation of geoheritage due to these disasters. Nonetheless, the area also holds significant potential as a promising tourist destination in Indonesia. To strengthen disaster risk reduction efforts in the geopark area, in-depth research on geoheritage and its relationship with geological disaster hazards is essential. This study employs a descriptive qualitative method, applying geoheritage assessments from the Geological Agency and creating hazard maps for geosites in Batur UGGp using QuantumGIS. The analysis of 21 geosites in Batur UGGp reveals that volcanic eruptions are the dominant disaster threat, with 15 geosites located in high-risk zone I, while the remaining are in risk zones II and III. Additionally, earthquakes also pose a potential threat to each geosite, although with relatively low frequency. The third threat is landslides, with at least 7 geosites identified as having potential landslide risks, with 44 recorded incidents between 2018 and 2023. From the geoheritage assessments conducted, indicators of scientific value and degradation of geoheritage can be used to obtain information about past disaster events as well as potential future disasters. This research also demonstrates that geoheritage can serve as an indicator or medium for understanding geological disasters.

Accretionary Wedge, Arc Magmatism and Fluid Migration in Northern Sumatra: Insight From Seismic Attenuation Tomography

AbstractThe first three‐dimensional (3‐D) P and S wave attenuation (Qp and Qs) tomography of the crust and upper mantle of the northern Sumatra subduction zone is determined. We adopt an improved calculation scheme to precisely measure attenuation factor t* values from velocity amplitude spectral ratios among different stations that recorded the same earthquake. Our tomographic results show that the forearc accretionary wedge in Sumatra exhibits a significant high‐attenuation (low‐Q) zone along the trench. The seismic attenuation characteristics of the forearc accretionary wedge are probably influenced by variations in temperature and water content. The middle and upper crust beneath active arc volcanoes shows low‐Q and high‐Qp/Qs, while the lower crust exhibits less low‐Q and low‐Qp/Qs, probably reflecting hot volcanic roots with different water saturations from the upper to lower crust. Beneath the Toba volcano that had a super‐eruption ∼74,000 years ago, a distinct low‐Qp/Qs zone is revealed, which may reflect a transport pathway of fluids and/or local melts ascending from a slab window. The subducting Indo‐Australian slab beneath the forearc island chain exhibits a low‐Q and low‐Qp/Qs belt, reflecting a moderate water saturation probably associated with backthrust faulting. High‐Q and high‐Qp/Qs zones appear along the slab surface, reflecting large amounts of fluids releasing from the slab dehydration, which may increase pore pressure and cause intense intraslab seismicity.

Pre-eruption Deformation Prior to 2018 Eruption of Anak Krakatau Volcano

Abstract Anak Krakatau is an active volcano situtated in Sunda Strait between Sumatera and Java that is frequently erupts. In 2018, Anak Krakatau eruupted where its eruptions destroys its western and south western flank that created a tsunami that swept across western Banten Province and southern Lampung Province, killed hundreds of casualties and destroyed homes in the shorelines. With the use of Differential InSAR analysis, we observe the dynamics of activity of Anak Krakatau starting from January 2018 until December 2019. To observe the unrest of Anak Krakatau prior and after the eruption, we’re using radar satellite imagery from Sentinel 1 from European Space Agency with temporal baseline every 12 days with total of 60 images being used. These images then processed using differential Interferometric Synthetic Aperture Radar (DInSAR) method and then being analysed the ups and downs patterns between 12-day-pairs. From our observation, deformation signals appeared in some interferogram pairs prior to eruption in December 2018. We also find that the activity of Anak Krakatau still rising after the eruption of 2018, showed by the upward trend that happened in the point samples near the vent. The graph analysed from InSAR pairs also show that there is a pattern of inflation and subsidence that shows the activity of Anak Krakatau. It is suggested that the supply from magma chamber played a role in the uplift of Anak Krakatau that happened in the time of our observation. We conclude that the activity of Anak Krakatau was detected prior the eruption and still not decline and will going to be active in some more time.

Evaluation of Geohazard Mitigation at Mount Rinjani Post-2018 Earthquake

Abstract Mount Rinjani is an active volcano located in the Rinjani-Lombok UNESCO Global Geopark area. The Caldera of Samalas, formed by the Old Rinjani/ Samalas eruption in 1257, is the most important geoheritage of Rinjani-Lombok Geopark. To reach the Caldera of Samalas geosite, people have to climb Mount Rinjani through one of six trekking trails. The Rinjani-Lombok Geopark is located on a small island that is vulnerable to natural disasters and geohazards such as earthquakes. As a result, disaster risk must be considered when developing tourism in the area. In 2018, the Lombok earthquake had a significant impact on trekking activities. More than 1000 trekkers were trapped inside Mount Rinjani. The earthquake triggered a coseismic landslide, damaged the trekking trail and caused the trekking activities to be closed for a year. Rinjani, on the other hand, has received the most foreign tourist visits of any volcano in Indonesia. Mount Rinjani National Park data over the past five years reveals an increase in tourists, indicating the need for a security system particularly disaster mitigation in tourism operations. This study was conducted to determine changes in disaster mitigation operations following the 2018 earthquake. The method used was an in-depth interview with Mount Rinjani National Park Office and Trekking tourism business actors, followed by image analysis that took into account geological condition, topography, rainfall and earthquake intensity. The study found that the impact of the earthquake, particularly coseismic landslides, was closely tied to geological conditions, topography and hydorological factors. In terms of disaster mitigation, Mount Rinjani National Park has made improvements in trekking registration and visitor data, but structural and non-structural trekking safety have to be improved by increasing the capacity of mountain guide and porter teams, as well as implementing a safety induction program before starting the trek.

Volcanic risk ranking and regional mapping of the Central Volcanic Zone of the Andes

Abstract. The Central Volcanic Zone of the Andes (CVZA) extends from southern Peru, through the Altiplano of Bolivia, to the Puna of northern Chile and Argentina, between latitudes 14–28° S of the Andean cordillera, with altitudes rising up to more than 4000 m above sea level. Given the large number of active volcanoes in this area, which are often located close to both urban areas and critical infrastructure, prioritization of volcanic risk reduction strategies is crucial. The identification of hazardous active volcanoes is challenging due to the limited accessibility, the scarce historical record, and the difficulty in identifying relative or absolute ages due to the extreme arid climate. Here, we identify the highest-risk volcanoes combining complementary strategies: (i) a regional mapping based on volcanic hazard parameters and surrounding density of elements at risk and (ii) the application of the recently developed volcanic risk ranking (VRR) methodology that integrates hazard, exposure, and vulnerability as factors that increase risk and resilience as a factor that reduces risk. We identified 59 active and potentially active volcanoes that not only include the volcanic centres with the most intense and frequent volcanic eruptions (e.g. the El Misti and Ubinas volcanoes, Peru) but also the highest density of exposed elements (e.g. the cities of Arequipa and Moquegua, Peru). VRR was carried out for 19 out of the 59 volcanoes, active within the last 1000 years or with unrest signs, highlighting those with the highest potential impact (i.e. Cerro Blanco in Argentina and Yucamane, Huaynaputina, Tutupaca, and Ticsani in Peru) and requiring risk mitigation actions to improve the capacity to face or overcome a disaster (e.g. volcanic hazard and risk/impact assessments, monitoring systems, educational activities, and implementation of early warning systems).

Magmatic activity in incipient continental break-up as revealed by coupling melt and fluid inclusions

Abstract Deciphering deep magmatic processes driving the onset of continental break-up is fundamental to constrain our understanding of plate tectonics. The East African Rift System (EARS) is the only currently active system on Earth to study distinct stages of rift evolution. We present a coupled analysis of melt and fluid inclusions in the Virunga Volcanic Province (VVP) offering an unprecedented insight into the dynamics of incipient rifting and its evolution. Our study highlights that melting of distinct metasomes in the deep lithosphere is a common feature of immature rifts. In the VVP, it leads to the emission of nephelinitic and basanitic melts at Nyiragongo and Nyamulagira volcanoes, respectively. Additionally, the chemical composition of melt and fluid inclusions supports the identification of another magmatic series in the area. Related alkali basaltic melts would be produced by contemporary melting of a less enriched domain in the upper lithosphere, more classically documented in mature rifts. Various extents of mixing and crystallisation of these three distinct magmatic series occur in the lower crust beneath the VVP where the barometric estimates are consistent with the presence of a thick seismic low velocity zone (LVZ). The involvement of alkali basaltic melts in the regional magma production could be also detected in the spread of gas emissions in the rift valley and in the fumaroles of the main active volcanoes. Melting of the corresponding mantle domain is an added source of gas release that may largely contribute to CO2 emissions along the EARS.

Quantifying Volumes of Volcanic Deposits Using Time-Averaged ASTER Digital Elevation Models

Quantifying the volume of erupted volcanic material, particularly lava flows and domes, provides critical insights into the dynamics of an eruption. This in turn aids in future hazard modeling, mitigation, and response. However, acquiring the necessary topographic datasets to calculate volumetric change is difficult, especially for active volcanoes in remote regions. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument has acquired global photogrammetric data since 2000, from which individual scene digital elevation models (DEMs) are created. We present a new straight forward method using ASTER DEMs to measure the volume of emplaced lava flows, domes, and tephra cones. We focus on five case studies that represent different eruption styles and products. For each of these we compare the results to those from previous studies that used alternative topographic datasets, such as synthetic aperture radar (SAR), airborne photogrammetry, or Light Detection and Ranging (LiDAR) measurements. These datasets, however, are expensive to acquire or lack the needed temporal resolution. We show that in nearly all cases, our volume results are either within the reported range for the eruption or ≤ 0.05 km3 of the previously reported value derived from SAR or LiDAR. The simplicity of the ASTER DEM approach combined with the global coverage of the data products enables more timely production of accurate volumetric data during and following an eruption, which can then be used to assess past and future eruption dynamics.