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The Eldgjá eruption is the largest basalt lava flood of the Common Era. It has been linked to a major ice‐core sulfur (S) spike in 939–940 CE and Northern Hemisphere summer cooling in 940 CE. Despite its magnitude and potential climate impacts, uncertainties remain concerning the eruption timeline, atmospheric dispersal of emitted volatiles, and coincident volcanism in Iceland and elsewhere. Here, we present a comprehensive analysis of Greenland ice‐cores from 936 to 943 CE, revealing a complex volatile record and cryptotephra with numerous geochemical populations. Transitional alkali basalt tephra matching Eldgjá are found in 939–940 CE, while tholeiitic basalt shards present in 936/937 CE and 940/941 CE are compatible with contemporaneous Icelandic eruptions from Grímsvötn and Bárðarbunga‐Veiðivötn systems (including V‐Sv tephra). We also find four silicic tephra populations, one of which we link to the Jala Pumice of Ceboruco (Mexico) at 941 ± 1 CE. Triple S isotopes, Δ33S, spanning 936–940 CE are indicative of upper tropospheric/lower stratospheric transport of aerosol sourced from the Icelandic fissure eruptions. However, anomalous Δ33S (down to −0.4‰) in 940–941 CE evidence stratospheric aerosol transport consistent with summer surface cooling revealed by tree‐ring reconstructions. Tephra associated with the anomalous Δ33S have a variety of compositions, complicating the attribution of climate cooling to Eldgjá alone. Nevertheless, our study confirms a major S emission from Eldgjá in 939–940 CE and implicates Eldgjá and a cluster of eruptions as triggers of summer cooling, severe winters, and privations in ∼940 CE. Plain Language Summary: The eruption of Eldgjá in the tenth century is the largest lava flood in the history of Iceland. Although Eldgjá emitted immense volumes of ash, lava, and gas, the exact timing and duration of this eruption, as well as its environmental and climatic impact remain unclear. Here, we provide a comprehensive chemical analysis of Greenland ice‐core records spanning the period 936–943 CE. We identify volcanic ash from at least three different Icelandic eruptions and confirm that there was a major ash and gas emission from Eldgjá in 939 CE. Using tree ring temperature estimates we find strong evidence for Northern Hemisphere climate cooling in the summer of 940 CE. However, the variety of volcanic ash identified in the ice‐cores shows that several Icelandic and Northern Hemisphere arc volcanoes were also erupting in this period. While Eldgjá remains the prime candidate, these additional eruptions complicate the attribution of reported climate and societal changes to Eldgjá alone. Ultimately, our study sheds new light on a cluster of volcanic eruptions between 936 and 943 CE and highlights the challenges of disentangling the individual contributions of multiple eruptions on the environment and climate. Key Points: New analyses of Greenland ice‐core records of volcanism between 936 and 943 CEIcelandic eruptions from Grímsvötn and Bárðarbunga‐Veiðivötn detected between 936 and 941 CE, and major Eldgjá emission in 939–940 CEVarious silicic eruptions identified, including the Jala Pumice (Mexico), providing new and valuable trans‐continental tephra isochrons [ABSTRACT FROM AUTHOR]

Pressure and stress perturbations associated with volcanic activity and geothermal production can modify the porosity and permeability of volcanic rock, influencing hydrothermal convection, the distribution of pore fluids and pressures, and the ease of magma outgassing. However, porosity and permeability data for volcanic rock as a function of pressure and stress are rare. We focus here on three porous tuffs from Krafla volcano (Iceland). Triaxial deformation experiments showed that, despite their very similar porosities, the mechanical behavior of the three tuffs differs. Tuffs with a greater abundance of phyllosilicates and zeolites require lower stresses for inelastic behavior. Under hydrostatic conditions, porosity and permeability decrease as a function of increasing effective pressure, with larger decreases measured at pressures above that required for cataclastic pore collapse. During differential loading in the ductile regime, permeability evolution depends on initial microstructure, particularly the initial void space tortuosity. Cataclastic pore collapse can disrupt the low‐tortuosity porosity structure of high‐permeability tuffs, reducing permeability, but does not particularly influence the already tortuous porosity structure of low‐permeability tuffs, for which permeability can even increase. Increases in permeability during compaction, not observed for other porous rocks, are interpreted as a result of a decrease in void space tortuosity as microcracks surrounding collapsed pores connect adjacent pores. Our data underscore the importance of initial microstructure on permeability evolution in volcanic rock. Our data can be used to better understand and model fluid flow at geothermal reservoirs and volcanoes, important to optimize geothermal exploitation and understand and mitigate volcanic hazards. Plain Language Summary: The volcanic rocks within a volcano or geothermal reservoir are frequently subject to changes in pressure and stress. Understanding whether pressures and stresses increase or decrease permeability, and by how much, is important for understanding volcano behavior and to maximize the efficiency of a geothermal reservoir. We performed experiments in which we measured the permeability evolution of porous volcanic rocks, three tuffs, as a function of pressure and stress. We also characterized their mechanical behavior. We first show that their mechanical behavior depends on composition: the more clay minerals and chlorite present, the weaker the tuff. We then show that increasing hydrostatic pressure (i.e., depth) decreases their permeability, but that differential loading in the ductile regime can either decrease or increase permeability. Rock permeability usually decreases during deformation in the ductile regime, and so the latter result is surprising. The observed differences in permeability evolution during ductile deformation is attributed to microstructural differences between the tuffs. However, changes in permeability as a function of pressure and stress are small when compared to other rocks, suggesting that tuff may help to maintain hydrothermal circulation in volcanoes and geothermal reservoirs, with attendant consequences for volcanic hazards and geothermal energy exploitation. Key Points: Tuffs are likely weakened by the presence clay minerals, chlorite, and zeolites due to a reduction in fracture toughnessPermeability of tuff decreases during hydrostatic pressurization, particularly following the onset of inelastic hydrostatic compactionPermeability of tuff can increase during ductile deformation due to flow‐parallel microcracks that form surrounding collapsed pores [ABSTRACT FROM AUTHOR]

Convective dynamics in a supercell thunderstorm, a volcanic eruption, and two pyrocumulonimbus (pyroCb) events are compared by computing cloud‐top divergence (CTD) with an optical flow technique called Deepflow. Visible 0.64‐μm imagery sequences from Geostationary Operational Environmental Satellites (GOES)‐R series Advanced Baseline Imager (ABI) are used as input into the optical flow algorithm. CTD is computed after post‐processing of the retrieved motions. Analysis is performed on specific image times, as well as the full time series of each case. Multiple CTD‐based parameters, such as the maximum and the two‐dimensional area exceeding a specified CTD threshold, are examined along with the optical flow‐retrieved wind speed. CTD is shown to accurately and quantitatively represent the behavior and magnitude of different deep convective phenomena, including distinguishing between convective pulses within each individual event. CTD captures updraft intensification as well as differences in convective activity between two pyroCb events and individual updraft pulses occurring within a single pyroCb event. Finally, the characteristics of high‐altitude smoke plumes injected by two separate pyroCb pulses are linked to CTD using ultraviolet aerosol index and satellite imagery. Optical flow‐derived parameters can therefore be applied to individual pyroCbs in real‐time, with potential to characterize pyroCb smoke source inputs for downstream smoke modeling applications and to facilitate future tools supporting air quality modeling and firefighting efforts. Plain Language Summary: Under certain weather conditions, wildfires can generate pyrocumulonimbus, which are deep, convective storms that inject smoke particles high into the atmosphere, resulting in significant aviation and climate impacts. This research tracks cloud‐top motion using computer vision algorithms and satellite data to compare the dynamics of pyrocumulonimbus with a volcanic eruption and supercell thunderstorm, which represent similar deep convective phenomena. The primary goal is to quantify updraft magnitude, duration, and evolution from space. Results show that cloud‐top motion accurately captures variations in updraft magnitude over time and distinguishes between different types of updrafts. Cloud‐top motion is likely more effective than traditional techniques at distinguishing individual, high‐altitude smoke injections from pyrocumulonimbus activity over specific fires. This research lays a foundation for improved smoke source inputs for downstream smoke modeling applications. Key Points: General dynamical characteristics for pyrocumulonimbus (pyroCb), volcano, and supercell cases are compared using satellite‐retrieved cloud‐top divergenceCloud‐top divergence time series analysis distinguishes individual convective pulses of pyroCb and volcano casesCloud‐top divergence is potentially related to the magnitude of pyroCb smoke plume injection height and mass [ABSTRACT FROM AUTHOR]

Large volcanic eruptions are known to influence the climate through a variety of mechanisms including aerosol‐forced cooling and warming via emitted CO2. The January 2022 Hunga shallow underwater eruption caused an increase in stratospheric water vapor, and demonstrated how the associated positive radiative forcing can be an important component of an eruption's climate forcing. We present interactive stratospheric aerosol model simulations of super‐volcanic eruptions with a range of SO2 emissions that can produce climate warming through feedback effects produced by a large igneous province (or "flood basalt") mid‐latitude super‐eruption using Goddard Earth Observing System Chemistry Climate Model climate model simulations. The model experiments suggest total SO2 emissions ≳4,000 Tg/4 Gt generate a multi‐year period of sustained aerosol absorptive local‐heating of the upper troposphere and lower stratosphere and hence produce net climate warming after strong initial cooling. The eruptions produce stratospheric water vapor increases of factors of 8–600. The initiation of these feedbacks within the simulations suggest they could occur for individual stratovolcano eruptions of the scale of the Toba or Tambora eruptions. We note the sensitivity of our results to volcanic sulfate aerosol microphysics and model chemistry. Plain Language Summary: Volcanic eruptions are important drivers of climate change throughout Earth's history. Using climate model experiments, we examine how massive volcanic eruptions can produce warmer climate conditions through an increase in stratospheric water vapor. We find that there is a range of volcanic sulfur dioxide emissions that can produce climate warming, but that the stratospheric water vapor increase occurs in all of our model experiments. Key Points: Stratospheric water vapor increases by a factor of 8–600 for volcanic SO2 emissions of 1,875–60,000 TgVolcanic SO2 emissions ≳4,000 Tg can produce net climate warming through feedbacksAbsorptive‐heating driven increases to stratospheric water vapor likely becomes the dominant forcing for volcanic super‐eruptions [ABSTRACT FROM AUTHOR]

On 8 October 2023 UTC, significant tsunamis were observed around Japan without any major tsunamigenic earthquake, associated with a series of 14 successive minor earthquakes (mb = 4.5–5.4) near Sofugan in the Izu‐Bonin Islands. To examine the cause of this tsunami, we estimated the horizontal locations of the tsunami source and temporal history of the seafloor displacement, using the tsunami data recorded by the ocean‐bottom pressure gauges >∼600 km away. Our results showed the main tsunami source was an uplift located at a caldera‐like bathymetric feature near Sofugan, suggesting the involvement of caldera activity in the tsunami generation. The total seafloor uplift was estimated as ∼4 m, and the uplift amount of each event gradually increased over time, reflecting an accelerating occurrence of volcanic unrest of the submarine caldera within only a few hours. Plain Language Summary: On 8 October 2023, a tsunami was widely observed along the Japanese coast without any major tsunamigenic earthquake, while a series of 14 small earthquakes occurred near Sofugan, located in the Izu‐Bonin Islands. Two possible candidates for this tsunami have been proposed, involving submarine volcanic processes or submarine landslides, but the exact cause remains unclarified. Using the tsunami data observed by the seafloor pressure gauges located more than 600 km from the tsunami source region, we analyzed sea height movements to obtain insights into the origin of this enigmatic tsunami. Our analysis showed that the tsunami source consisted of the seafloor uplift that repetitively occurred at a submarine volcanic caldera. Our results also showed an accelerating tsunami excitation, such that the amount of the seafloor uplift movement increased over time and the time intervals of the earthquakes gradually shortened. These results are consistent with the acceleration process of volcanic activity, suggesting the tsunami originated from the multiple sudden uplifts of the submarine caldera. Key Points: We revealed the source kinematics of enigmatic tsunamis excited near Torishima on 8 October 2023 with remote (>∼600 km) tsunami dataIts tsunami source was identified as repetitive seafloor uplift at the same location with gradually increasing amounts for later eventsThis unique feature of the accelerating caldera uplift within a few hours was brought about by the volcanic unrest of a submarine caldera [ABSTRACT FROM AUTHOR]

The processing of hundreds of Synthetic Aperture Radar (SAR) images acquired by two satellite systems: Sentinel‐1 and COSMO‐SkyMed reveals a decade of ground deformation for a ∼0.5 km diameter area around the summit crater of the only active carbonatitic volcano on Earth: Ol Doinyo Lengai in Tanzania. Further decomposing ascending and descending orbits when the appropriate SAR data sets overlap allow us to interpret the imaged deformation as ground subsidence with a significant rate of ∼3.6 cm/yr for the pixels located just north of the summit crater. Using geodetic modeling and inverting the highest spatial resolution COSMO‐SkyMed data set, we show that the mechanism explaining this subsidence is most likely a deflating very shallow (≤1 km depth below the summit crater at the 95% confidence level) magma reservoir, consistent with geochemical‐petrological and seismo‐acoustic studies. Plain Language Summary: We used data from two satellite systems, Sentinel‐1 and Cosmo‐SkyMed, to study Ol Doinyo Lengai, the only active carbonatitic volcano on Earth located in Tanzania. We analyzed hundreds of radar satellite images over a decade to understand changes in the ground deformation. By separating data from different orbits of the satellites and comparing them, we found that the ground at the volcano's summit was sinking at a rate of approximately 3.6 cm per year. Through simple geodetic modeling, we concluded that this sinking was likely caused by a shallow deflating magma reservoir, less than one km deep below the summit. This conclusion aligns with other scientific studies focusing on the volcano's petrology and geophysics. Key Points: InSAR time series show a ∼0.5 km diameter subsiding area around the summit crater at Ol Doinyo LengaiThe subsidence is likely due to a deflating shallow magma reservoir (point‐source)The modeled reservoir is less than 1 km deep below the summit crater, consistent with geophysical and geochemical studies [ABSTRACT FROM AUTHOR]

The formation of highly evolved, dacitic magmas has been attributed to various processes, including crystal fractionation, partial melting of overlying crust, and/or assimilation of crustal material into an evolving magma chamber. These processes are undoubtedly primary processes involved in the formation of dacites, but they may not be the only mechanism involved in the formation of high-silica dacites. For instance, mafic magma replenishment has been proposed as an additional mechanism but has not been assessed, and thus, its role has not been well-constrained. The Daliuchong volcano is the result of one of the largest eruptive events within the Tengchong Volcanic Field (TVF) in southwest China during the Early-Middle Pleistocene. Here, we conducted detailed mineral textures, mineral chemistry, and geochemical studies on Daliuchong pyroclastic rocks to explore the pre-eruptive storage conditions and evolution processes of the magma. The Daliuchong pyroclastic rocks are dacitic in composition. The samples show porphyritic textures characterized by phenocrysts of plagioclase, amphibole, clinopyroxene, orthopyroxene, and Fe-Ti oxides. Additionally, two distinct types of glomerocryst are identified: a gabbroic glomerocryst containing plagioclase + clinopyroxene + orthopyroxene ± Fe-Ti oxides assemblage and a dioritic glomerocryst containing plagioclase + amphibole ± pyroxene ± Fe-Ti oxides assemblage. Both phenocryst and glomerocryst show rich micro-textures. The Daliuchong dacite exhibits bulk compositional heterogeneity. Analysis of bulk-rock data suggests that this heterogeneity may arise from both the differentiation of the dacite itself and the injection of mafic magma. The compositional similarity between the Daliuchong dacite and experimentally produced partial melts of metamorphic basalt supports that the Daliuchong dacite was predominantly formed through the partial melting of the mafic lower crust. Thermobarometry estimation indicates that clinopyroxenes with high Mg# crystallized at 560-870 MPa, whereas amphibole and clinopyroxenes with low Mg# crystallized at 185-300 MPa. Based on the observed phase relations and the calculated crystallization conditions, we propose that during the differentiation of the Daliuchong dacite, heterogeneous dacitic magma formed by partial melting accumulated in a deep magma reservoir (21-32 km) before subsequently ascending toward shallower depths. Crystallization of plagioclase, amphibole, Fe-Ti oxides, and small amounts of pyroxene and apatite occurred at a shallower depth (7-10 km). The presence of coarse-sieve texture, fine-sieve texture, and oscillatory zoning with high amplitude in plagioclase suggests intermittent injection of mafic magma into the shallow magma reservoir, with the eruption of dacitic magma occurring after the final mafic magma replenishment. The petrological evidence above advocates that primitive magma replenishment could have been involved in the formation and triggered the eruption of dacite in the Daliuchong volcano. [ABSTRACT FROM AUTHOR]

Tortula atrovirens (Sm.) Lindb. is an important component of biological soil crusts and possesses an extraordinary tolerance against desiccation in dryland habitats. However, knowledge of the organelle genome of this desiccation-tolerant (DT) moss is still lacking. Here, we assembled the first reported Tortula organelle genome and conducted a comprehensive analysis within the Pottiaceae family. T. atrovirens exhibited the second largest chloroplast genome (129,646 bp) within the Pottiaceae, whereas its mitogenome (105,877 bp) and those of other mosses were smaller in size compared to other land plants. The chloroplast and mitochondrial genomes of T. atrovirens were characterized by the expansion of IR boundaries and the absence of homologous recombination-mediated by large repeats. A total of 57 RNA editing sites were detected through mapping RNA-seq data. Moreover, the gene content and order were highly conserved among the Pottiaceae organelle genomes. Phylogenetic analysis showed that bryophytes are paraphyletic, with their three lineages (hornworts, mosses, and liverworts) and vascular plants forming successive sister clades. Timmiella anomala is clearly separated from the monophyletic Pottiaceae, and T. atrovirens is closely related to Syntrichia filaris within the Pottioideae. In addition, we detected four hypervariable regions for candidate-molecular markers. Our findings provide valuable insights into the organelle genomes of T. atrovirens and the evolutionary relationships within the Pottiaceae family, facilitating future discovery of DT genetic resources from bryophytes. [ABSTRACT FROM AUTHOR]

Indigenous oral traditions of the Líl̓wat Nation recount observations of Qw̓elqw̓elústen (Mount Meager), a Garibaldi Volcanic Belt volcano in southwestern British Columbia, Canada; and associated eruptive activity, mass-wasting, and outburst flooding. We present Líl̓wat observations relating to Qw̓elqw̓elústen's ∼2360 cal year B.P. eruption and its aftermath, a devastating outburst flood down the Lillooet valley. The Copper Canoe story correlates with the event sequence of pyroclastic damming of the Lillooet River and an outburst flood traveling far downstream, interrupting salmon runs and displacing people. Other stories suggest an eruptive plume and fumaroles. Recounted valley-floor changes, with proximal scouring and downstream filling of marshes allowing human resettlement, closely parallel and augment geological evidence, showing that oral traditions are equally important in holding landscape history. Oral traditions portray dramatic landscape changes, some by the Transformers, said to have traveled this land to make imperfect things right. Geologically documented debris-flow delta progradation and infill of the upper 50 km of Lillooet Lake since ∼12 000 cal B.P. underscore the land's dynamism and the need for both sources to inform planning for future eruptive, mass-wasting, and flooding events. Traditional landscape knowledge, like Western science, is observational and evidence-based, though interpretations can differ given Indigenous belief in a sentient landscape, capable of acting with intention. Binding of stories to geographical locations has functioned as a powerful mnemonic device to preserve orally transmitted information across many generations. [ABSTRACT FROM AUTHOR]

Classification methods with Machine Learning have been used in various fields, including volcanology. This method makes it possible to automatically perform data processing and classification on large scale data in a short time. Seismic time series data from volcanic earthquakes of Mt. Merapi are classified into five types of earthquakes, i.e.: Volcanic Type A (VTA), Volcanic Type B (VTB), Multiphase (MP), Low-frequency (LF) and Rockfall (RF), with a total sample data of 266 earthquakes, could be classified automatically using machine learning. The features of the signal are taken from the dominant frequency value, the spectral pattern that is formed, and the amplitude value to differentiate the earthquake dataset into each class. Classification is done using the XGBoost algorithm. Tests were carried out using various data test–train percentage to get the best result. Based on the XGBoost function test, which the best value obtained with an accuracy of testing the data is 76.67% using the 70%:30% train–test scenario. The results of this accuracy value are greater when compared to the accuracy value of previous studies with the SVM method which is 74.4% accuracy. This research also has better results in spectral analysis with the results of spectral comparison plots that appear to show more significant differences. [ABSTRACT FROM AUTHOR]

During the last 10 kyr, significant subsidence and uplift occurred on Mayotte Island in the Comoros archipelago (Indian Ocean), but the role of volcanic processes in Holocene vertical movements has been neglected in the research so far. Here, we show that an abrupt subsidence of 6–10 m occurred between 9.4 and 10 kyr ago, followed by an uplift of the same amplitude at a rate of 9 mm/yr from 8.1 to 7 kyr ago. A comparison of the relative sea level of Mayotte and a reference sea level curve for the global ocean has been conducted using a modeling approach. This shows that an increasing and decreasing pressure at depth, equivalent to the process caused by a deep magma reservoir (50–70 km), was responsible for ~6–10 m subsidence and 6–10 m uplift, whereas loading by new volcanic edifices caused subsidence during the last few thousand years. Surface movements and deep pressure variations may be caused by pulses from the deep mantle, related to superplume activity, but uncertainties and unknowns about these phenomena are still present and further studies are needed. A better understanding of the volcano-tectonic cycle may improve assessments of volcanic hazards. [ABSTRACT FROM AUTHOR]

The results of a reconnaissance survey using direct-prospecting technology of satellite images and photographs frequency-resonance processing within some areas of coal basin and shale gas production in China, France, Ukraine, USA, Argentina, England, UAE are presented. The data of the local areas reconnaissance surveying within coal basins show the possibility of detecting oil, condensate and gas deposits in the deep and ultra-deep horizons of cross-section underneath coal deposits. Materials of experimental studies at the Fuman oil field site and the Luntan-1 deep well drilling site indicate the potential possibility and feasibility of direct-prospecting methods using in the process of selecting the most optimal sites of the deep exploratory wells for oil and gas drilling. Helium deposits may be discovered at an ultra-deep well drilling site in the Taklamakan Desert at depths of over 7120 m. By detailed scanning of this cross-section interval, the depths of helium accumulations in the reservoirs can be determined. The deep channels for fluids, chemical elements and minerals migration, filled with 1-6 groups of sedimentary rocks, were found in all surveyed shale gas production sites. The received measurement data of the work carried out can be considered as additional evidence in favor of the concept of deep (abiogenic) synthesis of hydrocarbons, including those in shale formations. Within the survey site in England a significant number of local zones of visible hydrogen degassing are located. It is advisable to conduct additional research on these sites in order to study these local zones in more detail. Experimental studies within area of shale oil in the Williston Basin also confirmed the presence of hydrocarbon deposits in the deep horizons of cross-section. It is advisable to carry out detailed geological exploration work in order to search for hydrocarbon deposits in coal and shale basins in various regions of the world! To the east of Williston Basin, a large cluster of basalt volcanic structures with hydrogen and living (healing) water, as well as the process of hydrogen and phosphorus migration into the atmosphere were revealed by instrumental measurements. In general, the materials of the experimental work carried out can be considered as additional evidence in favor of the volcanic model of formation of structural elements and the external appearance of the Earth's surface, as well as deposits of ore and combustible minerals and water. The research results indicate the feasibility of using mobile technology of frequency-resonance processing and decoding of satellite images and photographs for the detection and localization of oil and gas accumulation zones within large blocks and local areas. The use of super-operational and low-cost directprospecting technology will significantly speed up the exploration process for oil, gas, natural hydrogen and ore minerals, as well as reduce the financial costs of its implementation. [ABSTRACT FROM AUTHOR]

Explosive submarine arc volcanoes can cause tsunamis, affect climate, and pose hazards to airplanes and ships. Although 70 % of the Earth is submarine, only 15 % of Holocene arc volcanoes in the Smithsonian Global Volcanism database are submarine. Merging locations of active submarine hydrothermal vents in arcs and the above database, we found 71 unlisted submarine arc volcanoes. Using Baker [2017, doi: 10.1016/j.oregeorev.2017.02.006], only 44 % of hydrothermal vents in arcs are known. Only 77 of the vent fields are on volcanoes in the Smithsonian database. Assuming that unknown submarine arc volcanoes are present in the same proportions as unknown vents, there are ~160 as-yet undiscovered Holocene age submarine arc volcanoes. Using geophysical data, we located 291 unsurveyed seamounts 32 % of Holocene arc volcanoes are submarine.

This study utilizes 3D numerical models to simulate seismic resonances in a volcanic edifice, arising from the interaction between an externally excited wavefield and a magma chamber-conduit system. The magma chamber and conduit efficiently capture the incident wavefield of both P- and S-waves, excited by a high-frequency (~10 Hz) earthquake located within the edifice. Due to multiple internal reflections off the boundaries of the chamber and conduit, prolonged reverberations occur, which are guided along the conduit. Temporal and spectral analyses of synthetic seismograms illustrate that models with larger chambers and wider conduits consistently yield larger resonance amplitudes at distinct frequencies. Our models indicate that a larger magma chamber can produce an intensified scattered wavefield with a broad frequency range, observable up to several hundred meters away from the central conduit. Generally, these externally initiated ‘calabash resonances’ may appear as tremor-like signals at seismometers on the edifice, accompanying more conventional seismic events in its proximity.

During the last 10 kyr, significant subsidence and uplift occurred on Mayotte Island in the Comoros archipelago (Indian Ocean), but the role of volcanic processes in Holocene vertical movements has been neglected in the research so far. Here, we show that an abrupt subsidence of 6–10 m occurred between 9.4 and 10 kyr ago, followed by an uplift of the same amplitude at a rate of 9 mm/yr from 8.1 to 7 kyr ago. A comparison of the relative sea level of Mayotte and a reference sea level curve for the global ocean has been conducted using a modeling approach. This shows that an increasing and decreasing pressure at depth, equivalent to the process caused by a deep magma reservoir (50–70 km), was responsible for ~6–10 m subsidence and 6–10 m uplift, whereas loading by new volcanic edifices caused subsidence during the last few thousand years. Surface movements and deep pressure variations may be caused by pulses from the deep mantle, related to superplume activity, but uncertainties and unknowns about these phenomena are still present and further studies are needed. A better understanding of the volcano-tectonic cycle may improve assessments of volcanic hazards.

In the Michoacán region of central-western Mexico, the village of Turícuaro has for centuries been a center for metate production based on andesites exploited on the slopes of Hoya Urutzen and 'El Metate' volcanoes. Surveys have been conducted in this volcanic landscape, with the invaluable help of one of the last metateros (craftsmen) family of the village, the Vidalès, in order to reconstruct the strategies adopted through time to extract this andesite over a large territory. It has been possible to propose a first mapping as well as a relative dating of the various quarrying areas. Different types of exploitations have been described, from ancient quarries, associated with archaeological occupations, to current extraction sites. The morphology of the outcrops (walls, isolated blocks) partly conditioned the organization of the quarries (flat, organized on terraces, etc). It has also been possible to observe the different strategies and organization of work associated with this activity, through the observation of the abandoned blocks, waste and roughouts. Finally, this work offers a new perspective on Mesoamerican metate quarrying strategies.

In recent decades, nature has seen many anomalies with the environment, climate, and the processes taking place. This leads to a change in the temperature of the environment, the formation of meteorological processes that are not characteristic of a certain part of the planet and the triggering of emergency situations of a natural nature. The study seeks to fill the gap regarding the trends in the influence of man-made activities on the occurrence of natural disasters, their scale of distribution and consequences. The current study methodology is a combination of a literature review and bibliometric analysis to obtain the relevant impact of man-made activities to the extent of occurrence and impact of natural disasters. This report examines the main extraordinary processes that are observed around us and cause damage and departure from the normal way of life of people and the rest of the living world. It was found that many researchers indirectly confirm that anthropogenic activities can provoke negative natural events, or contribute to a significant increase in the scale of a dangerous natural phenomenon. Some of the reasons that cause them, usually independent of human activity or inaction, is also indicated. Several research works have noted that climate change over the past few decades and global warming are contributing to an increase in the frequency of natural disasters such as earthquakes, floods, tsunamis, landslides, etc. But we need to change our behaviour to minimize causing such phenomena.

The paper provides information on the objectives, methods, targets and some preliminary results of the expeditionary work carried out within the framework of the RSF project No.21-17-00049 by the employees of the Institute of Volcanology and Seismology of the FEB RAS, Institute of Marine Geology and Geophysics of the FEB RAS, Pacific Geographical Institute of the FEB RAS and Trofimuk Institute of Petroleum-Gas Geology and Geophysics of the SB RAS in 2022 and 2023. The main objectives of the expedition were geological volcanological, hydrogeological, geophysical, tephrochronological, and paleoseismological studies. In accordance with the set objectives, field teams were formed, which began work in February 2022. On the basis of the data obtained during the expedition, previously unknown hydrothermal manifestations and seismic events on Iturup Island were identified. A number of geophysical and paleomagnetic surveys were carried out.

This article provides a brief description of the expedition work conducted by the staff of the Institute of Volcanology and Seismology, FEB RAS, in the central part of the Eastern Volcanic belt of Kamchatka, and in the Kamchatka River valley in the Summer-Autumn of 2023. In order to study the conditions for the formation and discharge of thermal waters of large volcanic centers, to estimate the hydrothermal discharge of magmatic volatiles (primarily CO2), hydrochemical and gas testing was carried out on the thermal fields of the Kikhpinych and Bolshoi Semyachik volcanic massifs, and in the Uzon caldera. In parallel with geochemical sampling, aerial and infrared photography of thermal sites was carried out. To determine the degree of influence of volcanic and hydrothermal activity on the ion runoff into the Pacific Ocean, hydrochemical and hydrological works were carried out in the Kamchatka Riverv alley. A comprehensive study of unique alkaline cold springs was carried out in the Belaya River valley (Kamchatsky Peninsula). A large number of water and gas samples, sediments and mineral salts were collected for further analytical studies during the expedition works.

It is now generally accepted that large earthquakes can promote eruptions at nearby volcanoes. However, the prevalence of “triggered” eruptions, as well as the distance and timescale over which triggering occurs, remain unclear. Here, we use modern global earthquake and eruption records to compare volcanic eruption rates before and after large earthquakes with the time- averaged background eruption rate. We quantify the significance of observed deviations from the average eruption rate using Monte Carlo simulations. To integrate our findings with previous eruption triggering studies, we systematically vary the earthquake magnitudes we consider, as well as the distances and timescales used to calculate eruption rates. We also investigate the effects of earthquake depth and slip orientation. Overall, we find that post-earthquake eruption rates are around 1.25 times the average eruption rate within 750 km and one year following Mw ≥ 7 earthquakes, with above-average post-earthquake eruption rates possibly lasting for two to four years. By contrast, pre-earthquake eruption rates are around 0.9 times the average eruption rate within 750 km and182 days before Mw ≥7 earthquakes. Furthermore, deep earthquakes (≥7 0km) appear to more strongly affect eruption rates than shallow earthquakes, while earthquake slip orientation is also important. Further study of the relationships reported here represents a good opportunity to improve our understanding of tectono-magmatic relationships.

Intraplate earthquakes occur more frequently in the Japanese islands than in other regions. Large intraplate earthquakes in the island arc preferentially occur in strain concentration zones detected by geological and geodetic studies. Crustal heterogeneity plays a crucial role in generating large intraplate earthquakes and strain concentrations. Thus, we elucidated the crustal heterogeneities beneath a strain concentration area on the back‐arc side of the northeastern Japan Arc based on electrical resistivity, which is sensitive to weak zones in the crust. By deploying wideband magnetotelluric surveys, we revealed the three‐dimensional electrical resistivity structure in the crust, suggesting the coexistence of two different types of strain‐concentration mechanisms in the strain‐concentration area. The shallow conductive layers and lower‐crustal conductors appear to act as low‐elastic‐modulus and low‐viscosity areas, respectively, and are responsible for the strain concentration. We found shallow and lower‐crustal conductors in the strain concentration zone revealed by geological studies. Those conductive areas are considered to act as mechanically weak zones and cause stress loading on the brittle pars of pre‐existing faults, resulting in large intraplate earthquakes. The resultant earthquakes presumably contribute to strain accumulation on a geological timescale. In addition, a spatial correlation between the epicenters of large intraplate earthquakes and edges of lower‐crustal conductors implies the contribution of the fluids in the lower crust to the generation of large earthquakes. We also identified vertical conductors ranging from the lower crust to Quaternary volcanoes, which may indicate trans‐crustal magmatic systems under these volcanoes. Plain Language Summary: Intraplate earthquakes occur more frequently in the Japanese islands than in other regions worldwide. Large intraplate earthquakes in this region preferentially occur in high‐deformation zones, as detected by geological studies and global positioning system (GPS) measurements. Heterogeneous structure in the crust plays a crucial role in the generation of large intraplate earthquakes and high crustal deformations. Thus, we revealed the three‐dimensional crustal electrical resistivity structure beneath a strain‐concentration area in the northeastern Japan. The resistivity structure suggests the coexistence of two different mechanisms of high deformation. Shallow conductive layers and lower‐crustal conductors appear to act as low‐stiffness and low‐viscosity areas, respectively, leading to high crustal deformation. We found shallow and deep conductors in the high‐deformation zones revealed by geological studies. As both can act as weak zones, those conductors presumably play a key role in loading on faults, resulting in intraplate earthquakes. Because the epicenters of large intraplate earthquakes are positioned near the edges of lower‐crustal conductors, the fluids in those deep conductors possibly contribute to the generation of large earthquakes. We also revealed vertical conductors ranging from the deep crust to Quaternary volcanoes, which may indicate magma‐rich areas under these volcanoes. Key Points: The electrical resistivity structure suggests the coexistence of two strain‐concentration mechanisms in the strain‐concentration areaThe shallow conductive layers and lower‐crustal conductors act as low‐elastic‐modulus and low‐viscosity areas, respectivelyWeak zones in the crust, imaged as conductors, presumably cause stress loading on faults and contribute to large intraplate earthquakes [ABSTRACT FROM AUTHOR]

In 2014, the Pāhoa lava flow at Kīlauea, on the Island of Hawaiʻi (USA), entered a string of pre-existing meter-width ground cracks in the volcano’s East Rift Zone. The ground cracks transported lava below the surface in a direction discordant to the slope of the landscape. The cracks, which were 100s of meters long and 10s to 100s of meters deep, also widened by up to several meters as they filled, probably in part at the expense of adjacent cracks, which likely closed. Widening of the cracks caused shallow crustal blocks on the volcano’s flank to shift—this deformation was captured by a nearby GPS station and a borehole tiltmeter. The GPS station moved away from the cracks in response, while the tiltmeter showed tilting toward the cracks, consistent with opening. Noting that the lava-filled cracks act as top-fed dikes, we adapt existing theory for the thermo-rheological evolution of dikes to analyze transport of lava captured by ground cracks and propose mechanisms for the exit of the lava back to the surface. This study shows that ground cracks as narrow as 50 cm wide can facilitate the transport of advancing lava flows and can carry lava in directions that differ from those expected based on surface topography, invalidating flow path projections based on the assumption of subaerial flow. [ABSTRACT FROM AUTHOR]

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Abstract On 8 October 2023 UTC, significant tsunamis were observed around Japan without any major tsunamigenic earthquake, associated with a series of 14 successive minor earthquakes (mb = 4.5–5.4) near Sofugan in the Izu‐Bonin Islands. To examine the cause of this tsunami, we estimated the horizontal locations of the tsunami source and temporal history of the seafloor displacement, using the tsunami data recorded by the ocean‐bottom pressure gauges >∼600 km away. Our results showed the main tsunami source was an uplift located at a caldera‐like bathymetric feature near Sofugan, suggesting the involvement of caldera activity in the tsunami generation. The total seafloor uplift was estimated as ∼4 m, and the uplift amount of each event gradually increased over time, reflecting an accelerating occurrence of volcanic unrest of the submarine caldera within only a few hours.

Abstract The processing of hundreds of Synthetic Aperture Radar (SAR) images acquired by two satellite systems: Sentinel‐1 and COSMO‐SkyMed reveals a decade of ground deformation for a ∼0.5 km diameter area around the summit crater of the only active carbonatitic volcano on Earth: Ol Doinyo Lengai in Tanzania. Further decomposing ascending and descending orbits when the appropriate SAR data sets overlap allow us to interpret the imaged deformation as ground subsidence with a significant rate of ∼3.6 cm/yr for the pixels located just north of the summit crater. Using geodetic modeling and inverting the highest spatial resolution COSMO‐SkyMed data set, we show that the mechanism explaining this subsidence is most likely a deflating very shallow (≤1 km depth below the summit crater at the 95% confidence level) magma reservoir, consistent with geochemical‐petrological and seismo‐acoustic studies.

Mount Semeru eruption in 2020 and 2021 damaged 851 ha of productive land. Restoration of the affected lands requires information such as wide area, distribution, and eruption material characteristics. This community service aimed to provide a database as an overview of pyroclastic materials characteristics and elucidate potential-and-adaptive plants and microbes on post-Mt. Semeru eruptions. The volcanic ash contains significant elements (Al, Si, K, Ca, Ti, and Fe) and minor elements (V, Cr, Mn, Cu, Zn, Sr, Ba, Eu, and Re). Some of the plants that have survived post-eruption are annual shrubs and herbaceous plants such as grasses, so these plants can be used to restore the affected lands fertility after the Mt Semeru eruption. Based on economic evaluation and conditions in the field, the recommended adaptive plants are Pennisetum puparium and Musa paradisiaca. Both plants provide economic benefits for animal feed and farmers' income during post-eruption land recovery.

In 2022, volcanic activity in the Kuril Islands was increased. Alaid (Atlasov Island), Ebeko, Chikurachki (Paramushir Island) and Chirinkotan volcanoes (Chirinkotan Island, Northern Kuriles) were erupting. A summit effusive-explosive eruption occurred on the Alaid volcano from September till December: two lava flows 2.6 and 1 km long erupted along the southern slope of the volcano and at least 15 explosions occurred to a height of 2.5 to 6 km a.s.l. Ebeko Volcano, which has been dormant since December 2021, in June 2022 resumed the intense volcanic activity characteristic for recent years, characterized by frequent ash emissions. Over 7 months of volcano activity (from June till December 2022) more than 600 ash ejections were recorded, 253 of which were at a height of 3 or more km above sea level). By July, explosive activity increased sharply – 174 events were recorded (51 of them at a height of 3 or more km a.s.l.), which became the maximum value for the entire period of video observations carried out since October 2017. The Chikurachki volcano was characterized by an increased activity, in the period from January till October, at least 5 episodes of explosive activity were observed. Both single ejections and series of explosions to a height of 2–5 km a.s.l., as well as periods of relatively quiet emission of ash-gas mixture of various intensity were observed. On March 22, a single weak ash ejection (3 km a.s.l.) was recorded at the Chirinkotan volcano.

The results of field work at the active volcanoes Alaid and Ebeko, located in the northern part of the Kuril Island Arc, carried out in June−July 2023 are described. At Alaid volcano, the first survey of lava flows and fumarolic mineralization products of the 2022 eruption was carried out at various heights, including the summit, and geological sampling of the Taketomi cone and eruptive rocks of the eastern coast of Atlas Island was also conducted. An aerial photo and area temperature survey of the area occupied by the products of the 2022 eruption was undertaken at the summit of Alaid volcano using a high-precision quadrocopter equipped with a thermal imaging camera. At Ebeko volcano, mineral samples were taken from fumarole sites located on its eastern slope, and an aerial photo and area temperature survey were done.

Volcanoes produce a wide variety of hazards across varying spatial and temporal scales. When data are scarce on past eruptions and hazards, it can falsely imply low hazard recurrence and create challenges for robust hazard and risk assessment. Data quality and quantity vary considerably across different regions, volcanoes, and eruptions. Yet, there is a need for regional to global scale information on volcanic hazard and risk, where consistent and reproducible methods are applied. Such information is used by international stakeholders to inform funding priorities, risk reduction policies, and to highlight data and knowledge gaps, contributing towards the Sendai Framework's Sustainable Development Goals. Challenges in gathering this information can be most problematic where large populations are exposed to potential volcanic hazards but there are few comprehensive eruptive histories, as in sub-Saharan Africa. Here, we present a unique study to evaluate hazard and exposure for nine volcanoes in Ethiopia, Kenya and Cabo Verde, as part of an international project to develop multi-hazard Disaster Risk Country Profiles. We applied a two-stage expert elicitation process to volcanoes for the first time, and coupled the results with vent mapping, numerical hazard modelling, and GIS analysis of eight exposure categories to identify where high volcanic hazard and exposure coincide. Testing the sensitivity of our findings to input assumptions, to better understand where uncertainties lay, showed that improving our knowledge of past eruption volumes, frequencies, and dates was key to reducing uncertainty. Expert elicitations proposed that Fogo, Cabo Verde, is the most likely to erupt (eruption on average every 25 years), while Fentale (Ethiopia), Longonot and Suswa (Kenya) were elicited to have the greatest probability for a large explosive (VEI ≥ 4) eruption (on average every 400 years). Menengai and Longonot produce the larger exposure values across most VEI scenarios and categories of exposure, but population and GDP exposure was also large for more distal tephra fall and flows at Corbetti and Suswa, with order of magnitude increases expected between 2010 estimates and 2050 projections. Potentially high impact scenarios include tephra being dispersed across large cities (e.g. Nairobi, 55 km from Suswa) and key infrastructure (e.g. geothermal power station ∼2.5 km from Aluto), as well as important tourist destinations, seats of government and emergency management operations (e.g. islands east of Fogo). This study provided the first hazard and exposure assessment of its kind for these volcanoes and drew attention to volcanic risk at the levels required to inform policy and future in-country funding opportunities.

While 80% of tsunamis are related to earthquakes, recent examples of the Hunga Tonga Hunga Ha'apai (2022) tsunami as well as others from the Kick'em Jenny (2015), Saint Vincent (2021), and La Palma (2021) eruptions have sparked renewed reflection on how a tsunami warning system could also handle non-seismic tsunami events. A warning system is usually based on intrinsic and automatic detection by an instrumental network. In the case of tsunamis generated by earthquakes, it is the data from seismic stations and pre-established location and magnitude criteria that trigger actions from the Tsunami Service Providers (TSP, i.e., regional centers for threat information). Realtime sea level data then help constrain forecasts and determine the end of the threat. However, tsunamis generated by volcanic events are different from those induced by earthquakes in terms of source, detection, messaging, and modeling. In the Caribbean and Adjacent Regions, the UNESCO/IOC Intergovernmental Coordination Group for Tsunami and other Coastal Hazards Warning Systems created a task team to develop tsunami procedures in the case of a volcano crisis. We present here the recent progress of the task team. A bulletin is proposed to be issued by volcano observatories to the Tsunami Service Providers in the case of a potentially tsunamigenic volcano event. Derived from a Volcano Observatory Notice for Aviation (VONA) bulletin, this proposed VONUT bulletin, (Volcano Observatory Notice for tsUnami Threat), is under construction in collaboration with Caribbean volcano observatories and the Pacific Tsunami Warning Center, the TSP for the Caribbean. It was tested during the annual tsunami exercise CARIBE WAVE 2023, which includes testing the communications between the Tsunami Service Provider and nationally designated tsunami authorities. However, much more work is required to get a full operating warning system, as volcano scenarios and subsequent tsunami waves remain highly challenging to model and scale. [ABSTRACT FROM AUTHOR]

The Mount Meager Volcanic Complex (Qwe̓ lqwe̓ lústen or Mt. Meager) coincides tectonically with the intra-arc to back-arc transition zone and exhibits the loci of strain partitioning in response to a rapid change in orientation of the Pemberton and Garibaldi Arc segments that are coeval with a shift in Pacific plate motion after 5 Ma. This strain partition is manifested through development of a transpressional deformation from 5 to 1.9 Ma at the latitude of Mt. Meager. Mt. Meager is an active volcanic system with at least two explosive eruptions in the last 25 000 years, the most recent occurring around 2360 BP. Additionally, it is the site of the largest landslide in Canadian history, which occurred during the summer of 2010, originating from the southeastern side the massif. During early exploration at Mt. Meager, geothermal boreholes drilled to 3 km reached 270 °C but did not find sufficient permeability to sustain self-flowing conditions. To understand the geological challenges in Mt. Meager's geothermal exploration, we analyzed outcrop-scale faults and folds, incorporating structural mapping, volcanic rock paleomagnetism, and radiometric dating to establish kinematic history and kinematic compatibility of structural geology features, including faults and folds. Our findings suggest that stress partitioning during the last 5 Ma resulted in the formation of a transpressional structure exhibited as an elongate and rhomboidal structure at Mt. Meager with anomalously high topographic elevations which led to east northeast–west southwest crustal shortening and exhumation of crystalline basement. This new structural geology model improves our understanding of the geothermal reservoir and potentially significant geohazards. [ABSTRACT FROM AUTHOR]

The sudden eruption and tragedy of Mt. Ontake in 2014, a volcano located in central Japan, showed the fact that the volcanic eruption is the event with uncertainty, and it is important to let citizen to be aware of such uncertainty. To find measures to raise citizen's disaster awareness, this study focuses on the risk communication between citizens and volcano observatories, which are attached to universities. It examines the role of observatories, focusing on the activities of the Sakurajima Volcano Research Center, which monitors Mt. Sakurajima, one of the most active volcanoes in Japan, and suggests the necessity of human resource development that is able to connect citizen and science. [ABSTRACT FROM AUTHOR]

Pinatubo erupted during the first decadal survey of ocean biogeochemistry, embedding its climate fingerprint into foundational ocean biogeochemical observations and complicating the interpretation of long‐term biogeochemical change. Here, we quantify the influence of the Pinatubo climate perturbation on externally forced decadal and multi‐decadal changes in key ocean biogeochemical quantities using a large ensemble simulation of the Community Earth System Model designed to isolate the effects of Pinatubo, which cleanly captures the ocean biogeochemical response to the eruption. We find increased uptake of apparent oxygen utilization and preindustrial carbon over 1993–2003. Nearly 100% of the forced response in these quantities are attributable to Pinatubo. The eruption caused enhanced ventilation of the North Atlantic, as evidenced by deep ocean chlorofluorocarbon changes that appear 10–15 years after the eruption. Our results help contextualize observed change and contribute to improved constraints on uncertainty in the global carbon budget and ocean deoxygenation. Plain Language Summary: Oceanographers' understanding of ocean properties comes from research cruises that take scientific measurements in the same locations every ten years. However, the first of these research cruises were deployed just after a large volcanic eruption in 1991 called Pinatubo. The eruption cooled the planet for several years, including the upper ocean. Here, we investigate how this eruption affected ocean properties using two collections of simulations of the Community Earth System Model which is a mathematical representation of the Earth system. The first collection of simulations shows the response to the eruption, while the second collection shows how ocean properties would have changed if there had been no eruption. The difference thus tell us the influence of the eruption on ocean properties. We find an increase of oxygen and preindustrial carbon over 1993–2003 due to Pinatubo, as well as an increase of ventilation of the North Atlantic that appears years after the eruption. Key Points: Using a large ensemble model, we quantify the impact of Pinatubo on observed, externally forced decadal changes in ocean biogeochemistryNearly 100% of forced changes in apparent oxygen utilization and preindustrial carbon over 1993–2003 are attributable to PinatuboImpacts of Pinatubo last several decades, affecting interpretation of anthropogenic changes from physical and biogeochemical observations [ABSTRACT FROM AUTHOR]

During the “Godzilla” dust storm of June 2020, unusually high fluxes of mineral dust traveled across the Atlantic from the Sahara Desert, reaching the Caribbean Basin, Gulf Coast, and southeastern United States. Additionally, an eruption of the La Soufrière volcano on St. Vincent in April 2021 generated substantial ashfall in the southeastern Caribbean. While many studies have analyzed mineral dust’s ability to relieve nutrient limitation of phosphorus (P) in the P-stressed North Atlantic, less is known about the impact of extreme events and other natural aerosols on fluxes of P into seawater and from seawater into marine microbial cells. We quantified P and iron (Fe) content in mineral dust from the Godzilla dust storm and volcanic ash from the La Soufrière eruption collected at Ragged Point, Barbados. We also performed seawater incubations to assess the marine microbial response to aerosol deposition. Using environmentally-relevant concentrations of atmospheric particles for within the ocean’s mixed layer allowed us to draw realistic conclusions about how these deposition events impacted P cycling in situ. Volcanic ash has lower P content than mineral dust, and P in volcanic ash is far less soluble (~1%) than assumed in current atmospheric deposition models. Adding mineral dust and the volcanic ash leachate in concentrations representing different deposition scenarios increased soluble reactive phosphorus (SRP) concentrations in coastal seawater by ~7-32 nM. Phosphate uptake rate was stimulated in coastal seawater after either mineral dust or volcanic ash deposition at aerosol concentrations relevant to the Godzilla dust event, with ash eliciting the fastest uptake rate. Furthermore, high concentrations of both the mineral dust and volcanic ash led to slightly elevated alkaline phosphatase activity (APA) compared to the relevant controls, indicating higher potential for use of dissolved organic phosphorus (DOP) as a P source. Quantifying these aerosols’ impacts on P cycling is a significant step towards achieving a better understanding of their potential roles in relieving nutrient limitation and fueling the biological carbon pump. [ABSTRACT FROM AUTHOR]

Several satellite missions are currently available to provide thermal infrared data at different spatial resolutions and revisit time. Furthermore, new missions are planned thus enabling to keep a nearly continuous 'eye' on thermal volcanic activity around the world. This massive volume of data requires the development of artificial intelligence (AI) techniques for the automatic processing of satellite data in order to extract significant information about volcano conditions in a short time. Here, we propose a robust machine learning approach to accurately detect, recognize and quantify high-temperature volcanic features using Sentinel-2 MultiSpectral Instrument (S2-MSI) imagery. We use the entire archive of high spatial resolution satellite data containing more than 6000 S2-MSI scenes at ten different volcanoes around the world. Combining a 'top-down' cascading architecture, two different machine learning models, a scene classifier (SqueezeNet) and a pixel-based segmentation model (random forest), we achieved a very high accuracy, namely 95%. These results show that the cascading approach can be applied in near-real time to any available satellite image, providing a full description of the scene, with an important contribution to the monitoring, mapping and characterization of volcanic thermal features. [ABSTRACT FROM AUTHOR]

Enrolment in geology-related courses has declined over the last few decades, in part due to a lack of understanding of the subject and its relevance to contemporary society. Although a popular medium for entertainment, video games also hold significant pedagogical potential to overcome this problem by immersing players in geology-related topics through the portrayal of a broad range of geological disciplines in the medium's dynamic environments. This paper focuses on volcanology as portrayed in Nintendo's The Legend of Zelda series' (1986-present) Death Mountain, a recurring volcanic peak in the franchise. Volcanic features in each game are documented and compared to real-world examples to determine the accuracy of how the volcanism evolves over time across instalments in the series. I argue that the volcanic history of Death Mountain provides a reasonably realistic evolution, beginning with volcanic hazards like rockfalls and lava from an active stratovolcano, and progressing over time to introduce hydrothermal systems. Then, during divergent timelines, Death Mountain's volcanism shifts to either explosive, shallow-water eruptions or to showing evidence of massive explosive activity. Through this, I argue that the popularity of The Legend of Zelda series and the gradual introduction of volcanic features can be used together to change the perception of geology as "boring" and encourage people to study the subject by offering a fun and immersive means to engage with its content. [ABSTRACT FROM AUTHOR]

The eruption of the Hunga Tonga—Hunga Ha'apai (HTHH) volcano on 15 January 2022 injected about 150 Tg of water vapor (H2O), roughly 10% of the background stratospheric H2O content, to altitudes above 50 km. Simulations of the spatial evolution of the H2O cloud with the ICON‐Seamless model are very close to observations from the Aura Microwave Limb Sounder. The vertical transport of the H2O cloud had three phases: an initial subsidence phase, a stable phase, and a rising phase. Radiative cooling of H2O clearly affects the transport of the H2O cloud, as demonstrated with passive tracers, and is the main driver within the subsidence phase. It also counteracts the large‐scale rising motion in the tropics, leading to the stable phase, and modulates the large‐scale transport of the H2O cloud for about 9 months. This holds for different QBO phases, where the H2O cloud differs mainly in its vertical extent. Plain Language Summary: The eruption of the Hunga Tonga—Hunga Ha'apai (HTHH) volcano on 15 January 2022 injected about 150 Tg water vapor (H2O) to an altitude above 50 km. This is more than 10% of the total stratospheric H2O content. We study the distribution of the H2O cloud and its ascent into the mesosphere using observations from the Aura Microwave Limb Sounder satellite and by performing simulations of the cloud with the ICON‐Seamless model. The vertical transport of the H2O cloud had three phases: a subsidence, a stable, and a rising phase. The temperature inside the H2O cloud is lower than outside the cloud. This causes the subsidence of the H2O cloud and has consequences for the transport during the next months. From October 2022 on, the transport is mainly determined by the large‐scale wind patterns. Key Points: Radiative cooling of the H2O cloud influences the transport of the H2O cloud, stratospheric dynamics and, changes tracer transportRadiative cooling of the H2O cloud influences the cross equatorial transport of the H2O cloudThe phase of the QBO modulates the large‐scale transport and the vertical extension of the HTHH cloud [ABSTRACT FROM AUTHOR]

The Sheveluch volcano is the most active volcano in Kamchatka. The paroxysmal explosive eruption of the volcano that destroyed the lava dome in the volcanic crater continued on April 10–13, 2023. According to various satellite data, the height of the separate eruptive clouds probably exceeded 15 km above sea level. A powerful cyclone, which dominated the entire Kamchatka Peninsula, pulled the eruptive cloud to the west, turned it to the south, stretched it to the north, and directed it to the east from the volcano. The dynamics of the development of ash and aerosol clouds of this eruption is reflected in the animations made from a series of Himawari-9 satellite images in the VolSatView IS from 08:00 UTC on April 10 to 07:00 UTC on April 14 (http://d33.infospace.ru/jr%5fd33/materials/2023v20n2/283-291/1683110898.webm) and of the Arctica-M1 satellite from 16:00 to 21:30 UTC on April 10 (http://d33.infospace.ru/jr%5fd33/materials/2023v20n2/283-291/1683821166.webm). It was noted that the eruptive column was not vertical: for example, at the initial moment of the eruption on April 10 at 13:20 UTC, it deviated to the north–northeast; on April 11, at 12:00 UTC to the northwest; and, on April 12, at 7:00 UTC to the southwest. During the paroxysmal eruption, sulfur dioxide continuously entered the atmosphere, the maximum amount of which was released on April 10–11, as a result of the explosive destruction of the lava dome of the Sheveluch volcano. Ash clouds along with aerosol clouds on April 10–13 were stretched into a strip more than 3500 km long from west to northeast. On April 21–22, the Sheveluch aerosol cloud was observed in the region of the Scandinavian Peninsula. The total area of the territory of Kamchatka and the Pacific Ocean where ash and aerosol plumes and clouds were observed during the April 10–13 eruption was about 3 280 000 km2. The paroxysmal eruption of Sheveluch volcano belongs to the sub-Plinian type because it is characterized by a large height of the eruptive cloud and a long event duration. For this eruption, the Volcanic Explosivity Index is estimated to be 3–4. A detailed description of the paroxysmal explosive eruption of the Sheveluch volcano and the spread of the eruptive cloud was performed based on data from various satellite systems (Himawari-9, NOAA-18/19, GOES-18, Terra, Aqua, JPSS-1, Suomi NPP, Arctica-M1, etc.) in the information system "Remote Monitoring of Kamchatka and Kuril Islands Volcanic Activity" (VolSatView, http://kamchatka.volcanoes.smislab.ru). [ABSTRACT FROM AUTHOR]

The results of instrumental observations carried out at observatories of the INTERMAGNET network and at the Wakkanai ionospheric sounding station were used to show that the vigorous effusion–explosion eruption of Shiveluch Volcano occurring on April 10, 2023 was accompanied by variations in the Earth's magnetic field, as well as by changes in the critical frequency of the ionospheric F 2 layer. [ABSTRACT FROM AUTHOR]

There are currently no quantitative short-term eruption forecasts based on peer-reviewed and validated models that are operational for New Zealand's volcanoes. Specific forecasts produced for work-risk assessments are not generally publicised. During a volcanic crisis, eruption forecasts are demanded under high stress and time-restricted conditions. Many forecasting options exist but none are proven as universally viable, with testing and calibration limited to the hindcasting of specific events. Here, we compare the requirements of six methods with currently available data and monitoring capabilities at each of New Zealand's volcanoes to determine which methods are currently feasible, as well as those options that may be implemented with additional effort or equipment. In New Zealand, the major limiting factor in method selection is the low number of past instrumentally monitored eruptions. This data gap may be filled by carefully selected analogue data from a global volcano set and expert knowledge. Event trees and the failure forecasting method may be set up at most volcanoes with minimal effort, but the latter can only forecast eruption onset time. Expert interpretation is the only method available in New Zealand for any forecast output type. [ABSTRACT FROM AUTHOR]

Five samples of voltaite-group minerals from post-volcanic occurrences (geothermal fields and solfatara at pyroclastic flow) and from pseudofumaroles born by coal fires are characterized by single-crystal X-ray diffraction, scanning electron microscopy and electron microprobe analysis. The studied minerals include ammoniomagnesiovoltaite, ammoniovoltaite, voltaite and magnesiovoltaite. The quadrilateral of chemical compositions is determined by monovalent cations such as (NH4)+ and K+ and divalent cations such as Fe2+ and Mg2+. Minor Al can occur in the Fe3+ site. Minor amounts of P, V can occur in the S site. Ammonium members are described from geothermal fields, expanding the mineral potential of this type of geological environment. All minerals are cubic, space group Fd-3c, a = 27.18–27.29 Å, V = 20079–20331 Å3, Z = 16. No clear evidence of symmetry lowering (suggested for synthetic voltaites) is observed despite the chemical variation in the studied samples. Ammonium species tend to have a larger a lattice parameter than potassium ones due to longer distances (A = N or K). The systematically shorter obs (Me2+ = Fe, Mg; ϕ = O, H2O) in comparison to calc bond lengths can be explained as a consequence of mean bond length variation due to significant bond length distortion in Me2+ϕ6 octahedra Me2–O2—2.039–2.055 Å; Me2–O4—2.085–2.115 Å; and Me2–Ow5—2.046–2.061 Å, with bond length distortion estimated as from 0.008 to 0.014 for different samples. [ABSTRACT FROM AUTHOR]

The Experiment to Study Thunderstorm High-Energy Radiation (ESTHER) is a small project of the Italian National Institute for Astrophysics (INAF), devoted to the study of high-energy emissions from thunderstorms, such as Terrestrial Gamma-ray Flashes and gamma-ray glows, which will start in 2024. In order to reduce the absorption typically undergone by gamma-ray radiation in the lower layers of the atmosphere and make these events detectable on the ground, the ESTHER set-up will be installed at high altitudes on Mt. Etna (Italy). We carried out a detailed analysis of lightning occurrence in this geographic region in order to test how suitable such a location is for the installation of a detection system to investigate thunderstorms and related emissions. The analysis pointed out a strong clustering of lightning in the proximity of the mountain peak and over the main volcano craters, where the frequent presence of volcanic ashes could increase, under the conditions of humid air typical of thunderstorms, electrical conductivity. An estimate of the gamma-ray absorption in the air undergone by typical TGF radiation allowed us to evaluate the suitability of two possible installation sites suggested for the project. This study represents a preliminary work for ESTHER and serves as a launching pad for future analyses. [ABSTRACT FROM AUTHOR]

The formation of highly evolved, dacitic magmas has been attributed to various processes, including crystal fractionation, partial melting of overlying crust, and/or assimilation of crustal material into an evolving magma chamber. These processes are undoubtedly primary processes involved in the formation of dacites, but they may not be the only mechanism involved in the formation of high-silica dacites. For instance, mafic magma replenishment has been proposed as an additional mechanism but has not been assessed, and thus, its role has not been well-constrained. The Daliuchong volcano is the result of one of the largest eruptive events within the Tengchong Volcanic Field (TVF) in southwest China during the Early-Middle Pleistocene. Here, we conducted detailed mineral textures, mineral chemistry, and geochemical studies on Daliuchong pyroclastic rocks to explore the pre-eruptive storage conditions and evolution processes of the magma. The Daliuchong pyroclastic rocks are dacitic in composition. The samples show porphyritic textures characterized by phenocrysts of plagioclase, amphibole, clinopyroxene, orthopyroxene, and Fe-Ti oxides. Additionally, two distinct types of glomerocryst are identified: a gabbroic glomerocryst containing plagioclase + clinopyroxene + orthopyroxene ± Fe-Ti oxides assemblage and a dioritic glomerocryst containing plagioclase + amphibole ± pyroxene ± Fe-Ti oxides assemblage. Both phenocryst and glomerocryst show rich micro-textures. The Daliuchong dacite exhibits bulk compositional heterogeneity. Analysis of bulk-rock data suggests that this heterogeneity may arise from both the differentiation of the dacite itself and the injection of mafic magma. The compositional similarity between the Daliuchong dacite and experimentally produced partial melts of metamorphic basalt supports that the Daliuchong dacite was predominantly formed through the partial melting of the mafic lower crust. Thermobarometry estimation indicates that clinopyroxenes with high Mg# crystallized at 560–870 MPa, whereas amphibole and clinopyroxenes with low Mg# crystallized at 185–300 MPa. Based on the observed phase relations and the calculated crystallization conditions, we propose that during the differentiation of the Daliuchong dacite, heterogeneous dacitic magma formed by partial melting accumulated in a deep magma reservoir (21–32 km) before subsequently ascending toward shallower depths. Crystallization of plagioclase, amphibole, Fe-Ti oxides, and small amounts of pyroxene and apatite occurred at a shallower depth (7–10 km). The presence of coarse-sieve texture, fine-sieve texture, and oscillatory zoning with high amplitude in plagioclase suggests intermittent injection of mafic magma into the shallow magma reservoir, with the eruption of dacitic magma occurring after the final mafic magma replenishment. The petrological evidence above advocates that primitive magma replenishment could have been involved in the formation and triggered the eruption of dacite in the Daliuchong volcano.

Enrolment in geology-related courses has declined over the last few decades, in part due to a lack of understanding of the subject and its relevance to contemporary society. Although a popular medium for entertainment, video games also hold significant pedagogical potential to overcome this problem by immersing players in geology-related topics through the portrayal of a broad range of geological disciplines in the medium’s dynamic environments. This paper focuses on volcanology as portrayed in Nintendo’s The Legend of Zelda series’ (1986-present) Death Mountain, a recurring volcanic peak in the franchise. Volcanic features in each game are documented and compared to real-world examples to determine the accuracy of how the volcanism evolves over time across instalments in the series. I argue that the volcanic history of Death Mountain provides a reasonably realistic evolution, beginning with volcanic hazards like rockfalls and lava from an active stratovolcano, and progressing over time to introduce hydrothermal systems. Then, during divergent timelines, Death Mountain’s volcanism shifts to either explosive, shallow-water eruptions or to showing evidence of massive explosive activity. Through this, I argue that the popularity of The Legend of Zelda series and the gradual introduction of volcanic features can be used together to change the perception of geology as “boring” and encourage people to study the subject by offering a fun and immersive means to engage with its content.

In 2002 and 2003 a collaborative effort was undertaken between Lawrence Berkeley National Laboratory, Sandia National Laboratories, the U.S. Geological Survey (USGS) Menlo Park, the USGS Hawaiian Volcano Observatory, and Electromagnetic Instruments Inc. to study the Kīlauea volcano in Hawaii using the magnetotelluric (MT) technique. The work was motivated by a desire to improve understanding of the magma reservoirs and conduits within Kīlauea and the East and Southwest Rift zones, which has implications for understanding Kīlauea's plumbing system. An improved understanding of the rift zones has implications in understanding large-scale landslides that are generated in the Hilina Slump, which produce significant impacts on coastal communities. Up to eight stations operated simultaneously, with multiple remote reference sites, and data were processed using multi-station robust processing techniques. In total, data were acquired at 70 sites over the Southwest and East rift zones. Good to excellent quality data were obtained even in the harshest conditions, such as those encountered on the fresh lava flows of the East Rift Zone, where electrical contact resistances are on the order of 100 kΩ. A three-dimensional (3D) MT model study was done to guide interpretation of the observed MT measurements. Synthetic modeling demonstrates that conductive bodies in the upper 3 km can be spatially resolved where MT station sampling is good. Resistivity anomalies in the 3D inversions have a high degree of spatial correlation with previously published seismic velocity anomalies beneath Kīlauea. Melt fractions between 0.096 and 0.117 are calculated for the Kīlauea and Puʻuʻōʻō low resistivity anomalies, respectively.

На полуострове Камчатка в 2019 г. были возобновлены наблюдения за наклонами земной поверхности. Целью наблюдений является получение дополнительной информации о медленных движениях земной поверхности, обусловленных различными геодинамическими явлениями. В первую очередь, это относится к изучению связи деформации с региональной сейсмичностью, а также с подготовкой и динамикой вулканических извержений. Помимо изучения медленных движений, сеть наклономерных станций может использоваться для исследования земных приливов. Перечисленные выше задачи могут быть решены лишь при наличии соответствующих средств сбора, обработки и хранения получаемой информации. Основной технической сложностью при создании аппаратурно-программного комплекса (АПК), являлась разнотипность имеющегося в наличии оборудования. В работе приводится описание программных и технических решений, использованных при реорганизации сети наклономерных наблюдений. В качестве примера работы комплекса приводятся результаты ретроспективного анализа данных, позволяющие предполагать наличие отклика в наклономерных данных на Земные приливы. Основное направление дальнейшего развития АПК — создание дополнительных программных модулей обработки, которые могут быть выборочно использованы в зависимости от поставленной задачи. Кроме того, ведется работа по предоставлению пользовательского доступа в исследовательских целях к накопленному архиву данных.

3D analysis of the magma transport and accumulation mechanism in the structure and basement of the Klyuchevskoy volcano preceding 11 eruptions in 2003-2021 has been performed. Using the Frac-Digger method and seismological data from the Kamchatka Branch Federal Research Center United Geophysical Survey Russia Academy of Sciences it has been shown that magma transport from the deep crustal magma chamber (−30 km) is carried out in the vertical fracturing (dykes) mode to the peripheral shallow magma chamber (+1 km). The feeding dykes orientation corresponds to geomechanical conditions of radial or N-NNE extension. This is followed by inclined dykes and sills of various orientations from the peripheral magmatic chamber. Magma accumulation in the peripheral magmatic chamber in the form of sills (in the horizontal fracturing mode at elevations of +0,3 to +2,3 km) contributes to the efficiency of magma degassing and heat exchange with meteoric waters, and to the formation of a high-pressure vapour-gas reservoir with subsequent venting of the volcano channel and its eruption. Three-dimensional analysis of the distribution of flank eruptions of the Klyuchevskoy volcano in 1932-2021 (16 cinder cones) shows their association with two main low-inclined structural surfaces. Changes in the drainage level of the magmatic system are reflected in the volumes and geochemical history of the 1932-2021 flank eruption products.

Tortula atrovirens (Sm.) Lindb. is an important component of biological soil crusts and possesses an extraordinary tolerance against desiccation in dryland habitats. However, knowledge of the organelle genome of this desiccation-tolerant (DT) moss is still lacking. Here, we assembled the first reported Tortula organelle genome and conducted a comprehensive analysis within the Pottiaceae family. T. atrovirens exhibited the second largest chloroplast genome (129,646 bp) within the Pottiaceae, whereas its mitogenome (105,877 bp) and those of other mosses were smaller in size compared to other land plants. The chloroplast and mitochondrial genomes of T. atrovirens were characterized by the expansion of IR boundaries and the absence of homologous recombination-mediated by large repeats. A total of 57 RNA editing sites were detected through mapping RNA-seq data. Moreover, the gene content and order were highly conserved among the Pottiaceae organelle genomes. Phylogenetic analysis showed that bryophytes are paraphyletic, with their three lineages (hornworts, mosses, and liverworts) and vascular plants forming successive sister clades. Timmiella anomala is clearly separated from the monophyletic Pottiaceae, and T. atrovirens is closely related to Syntrichia filaris within the Pottioideae. In addition, we detected four hypervariable regions for candidate-molecular markers. Our findings provide valuable insights into the organelle genomes of T. atrovirens and the evolutionary relationships within the Pottiaceae family, facilitating future discovery of DT genetic resources from bryophytes.