Volcano Research Articles

Surface Pressure Semidiurnal Tides and the Stratospheric Quasi‐Biennial Oscillation: Synchronization and Disruption

AbstractAtmospheric surface pressure provides valuable information on the vertical dynamical structure of the atmosphere. Previous studies have reported that among the waves observed in surface pressure, semidiurnal tides (SDTs) are significantly affected by the stratospheric Quasi‐Biennial Oscillation (QBO). Using historical surface‐pressure observations and the Earth‐system model MRI‐ESM2.0, this study confirms that SDTs and the QBO are synchronized, such that SDT amplitude increases or decreases, respectively, at a rate of ∼1 Pa per 20 ms−1 during westerly or easterly phases of the QBO at 30 hPa. Our numerical simulations and a linear analytical model support the QBO‐SDT relationship being dynamically forced by background zonal winds rather than by anomalous ozone radiative heating. We also find that the QBO‐SDT relationship was notably disturbed by the volcanic eruptions of Mount Agung in 1963 and Mount Pinatubo in 1991, during which increased shortwave radiative absorption caused by stratospheric aerosol enhanced the SDT amplitude. Short‐lived El Nino events also occurred, moistening the upper troposphere to provide extra solar heating when volcanic aerosol was transported to higher latitudes. The influence of volcanic eruptions and El Nino events overlap with the QBO frequency band, jointly working as “noise” in QBO‐SDT synchronization.

Volcanic aerosols captured by plants: A study of nanoparticles and their chemical composition.

Nanoparticles (NPs) exhibit high reactivity and mobility in the environment, and a significant capacity to penetrate living organisms, potentially leading to harmful effects. Volcanoes are the second major source of natural NPs emitted into the atmosphere, with an estimated flux of 342 Tg/year. Few studies have focused on their fate. Thanks to technological advances in single-particle inductively coupled plasma mass spectrometry (spICP-MS), this trend is starting to reverse. La Soufrière volcano in Guadeloupe, chosen as a case study, exhibits increasing hydrothermal activity since its last eruption in 1530. This study aims to characterize NPs produced during volcanic activity by analysing ancient ash deposits, as well as those formed during periods of volcanic inactivity by examining condensates near fumaroles, as ultrafine particles are primarily generated through gas condensation. In this study, plants are utilized as samplers for NPs produced by fumarole activity. The use of a ICP-MS time-of-flight in single particle mode (spICP-ToF-MS), combined with data processing techniques such as hierarchical agglomerative clustering, enables the detailed characterization of NPs by determining their multi-element composition, concentration, and mass distribution. The results demonstrate that plants can effectively serve as samplers, even under the extreme environmental conditions present at the volcano's summit. However, differences in their efficiency at trapping particles on leaf surfaces can be attributed to varying physical characteristics of the plants. The spICP-ToF-MS analysis identified three types of multi-elemental NPs (NP-Al+Si, NP-Al+Fe, NP-Ti+Al) and three mono-elemental NPs (NP-Al, NP-Si, NP-Fe). Additionally, NPs containing trace elements were detected exclusively in undiluted Sphagnum pore water, where one tri-elemental NP (Sr-Ce-La), one bi-elemental NP (CeLa), and nine mono-elemental NP families (Cr, Cu, Zn, Sr, Y, Zr, Ba, La, Ce) were identified. Elements with potential negative effects on biota such as Cu, Zn, and Cr were also highlighted. Furthermore, the composition of the total of NPs (excluding families) is compared with elemental ratios from materials of different origins (volcanic, detrital, atmospheric) to validate their volcanic source.

Constraining volcanic vent parameters to understand the 2007 brightness surge in Io's Tvashtar plume: A DSMC approach

Constraining volcanic vent parameters to understand the 2007 brightness surge in Io's Tvashtar plume: A DSMC approach

A robust reduction in near-surface wind speed after volcanic eruptions: Implications for wind energy generation.

Near-surface wind speed (NSWS), a determinant of wind energy, is influenced by both natural and anthropogenic factors. However, the specific impacts of volcanic eruptions on NSWS, remain unexplored. Our simulations spanning the last millennium reveal a consistent 2-year global NSWS reduction following 10 major historical eruptions. This equates to an NSWS decrease of approximately two inter-annual standard deviations from AD 851 to 1849. This reduction is linked to the weakening of subtropical descending air and a decrease in downward momentum flux, triggered by volcanic aerosol forcing. The 1815 Tambora eruption, one of the most powerful in recent history, led to a ∼9.2% reduction in global wind power density in the subsequent 2 years. Our research fills a knowledge gap, establishes a theoretical foundation for empirical studies, and highlights the potential wind energy risks linked to large atmospheric aerosol injections, including volcanic eruptions, nuclear warfare, and climate intervention.

Advancements in Geohazard Investigations: Developing a Machine Learning Framework for the Prediction of Vents at Volcanic Fields Using Magnetic Data

This study investigates the application of machine learning techniques for predicting volcanic vent locations based on aeromagnetic geophysical data. Magnetic data, known to reflect subsurface geological structures, presents a valuable source of information for understanding volcanic activity. Leveraging this data, we aim to develop and validate predictive models capable of discerning the presence of volcanic vents. Through a comprehensive data analysis, feature engineering, and model training, we explore the intricate relationships between magnetic variations and volcanic vent locations. Various machine learning algorithms were evaluated for their efficacy in binary classification, with a focus on identifying areas with a high likelihood of volcanic vent presence. The Random Forest model (RFM) was adopted given its high performance metrics, achieving a prediction accuracy of 92%. Our results demonstrate the successful prediction of volcanic vent locations, with a significant correlation of 86% between the actual and predicted vent locations and a high Degree of Certainty (DC) at 97%. This research contributes to the advancement of geospatial data analysis within the field of geoscience, showcasing the potential of machine learning in interpreting and utilizing magnetic data for volcanic hazard assessment and early warning systems. The findings represent a significant step towards enhancing our understanding of volcanic dynamics and improving the predictive tools available for volcanic hazard assessment.

Spatial distribution and structural analysis of the Neogene Siroua volcanic field (Moroccan Atlas Mountains)

Monogenetic volcanic fields develop worldwide in different geodynamic settings, and understanding their evolution may provide crustal, thermal, and topographical constraints. We focus on the small monogenetic Siroua volcanic field that has formed since the late Miocene along the tectonic lineament separating the High Atlas and the Anti-Atlas Mountains of Morocco, though the evolution of which is still unclear. We investigate the formation and evolution of the Siroua monogenetic field using geostatistical methods that allow us to classify the spatial distribution of vents in their geological contexts. In addition, we use aeromagnetism to obtain information about the tectonic structures underlying the field. Each method is evaluated separately, and then combined to discuss the relationship between the volcanism and the tectonic framework at regional and local scales. Our findings indicate that although vents are broadly randomly distributed, some correlation between volcanic alignments and the structural framework is locally observed. These findings corroborate existing knowledge about the influence of pre-existing structures on the propagation of magmas and on the spatial distribution of volcanic vents within monogenetic volcanic fields.

Changes in total sulfur of lake sediments from central-eastern China linked to volcanic aerosol and human activity

Investigations into the repercussions of human activities on global climate and the ecological environment have received widespread attention. Over the past century, research has primarily focused on the impact of heavy metals and nutrients on lake ecosystems, along with their links to human activities. However, there is a noticeable dearth in explorations of historical variations in sulfur (S), an element that also has complex adverse effects on the environment and ecosystems. Here, we present an approximately 1800-year record of the total S (TS) content of sediments in Lake Nvshan, central-eastern China. The results provide evidence to indicate that high (low) TS contents in Lake Nvshan sediments are associated with strong (weak) volcanism in the Northern Hemisphere on multi-century scales. We also observed significant enhancement of TS content at 1750 and 1900 CE, which corresponded to a significant increase in the regional population at these times. We thus infer that elevations in TS levels prior to the increase in human activities likely resulted from increased volcanisms that led to greater inputs of sulfate from the stratosphere into the lake. Subsequently, the increases in TS contents could be attributed to intensified human industrial activities. Our findings revealed that volcanically derived sulfates have been supplanted by anthropogenically driven increases in the levels of sulfides as the primary factor influencing sediment TS contents in Lake Nvshan. These findings could elucidate how human activities have steered lake systems away from their natural baseline, thereby augmenting our understanding of their broader environmental impact.

Assessing natural radioactivity risks and heavy metals pollution in Al-Lisi volcanic mountain, Dhamar city, Yemen

Assessing natural radioactivity risks and heavy metals pollution in Al-Lisi volcanic mountain, Dhamar city, Yemen

Вертикальні провалені отвори до вулканічних печер на поверхні Марса

Studies of Mars have indicated the presence of caves of volcanic and possibly glacial origin on its surface. During volcanic eruptions, flows of lava flow out. As they cool, they are covered with a hard crust and form lava tubes. After the eruption is over, the lava flows out of the tubes at the lowest point and leaves the cavity. Therefore, lava caves are located on the slopes of volcanoes close to the surface. Sometimes their upper part collapses. A large part of the surface of Mars is covered with volcanic craters and mountain ranges. Dark, rounded spots were found in photographs of one of the volcanic plateaus of Tharsis. Their study showed that they are entrances to volcanic caves. The relative youth of these formations is indicated by the sharp edges of these dips. Lava tubes on Mars appear as straight chains of collapses with flat bottoms and nearly vertical slopes. Such objects should become the object of research by future settlers.

Distinct Radiative and Chemical Impacts Between the Equatorial and Northern Extratropical Volcanic Injections

AbstractStratospheric volcanic aerosols can affect the global radiative balance and stratospheric composition. In this study, we analyze ensemble experiments with an interactive stratospheric aerosol microphysical general circulation model, designed to assess the climate forcing from large‐magnitude explosive eruptions in the tropics and northern extratropics. Previous studies have generally identified a lower radiative forcing from extratropical eruptions from the shorter stratospheric lifetime of volcanic sulfate aerosols. However, our study finds that both the shorter lifetime and lower effective radiative forcing (ERF) efficacy contribute to the lower ERF in the northern extratropical eruptions. The simulated 2‐year averaged ERF efficacy in northern extratropical eruptions is 22% lower than that in the equatorial eruptions due to the seasonal mismatch of peak stratospheric aerosol optical depth and solar radiation in the first year after a northern extratropical volcanic eruption. Additionally, equatorial eruptions accelerate the Brewer‐Dobson circulation (BDC), while northern hemispheric (NH) extratropical eruptions decelerate the BDC branch in NH and accelerate the BDC branch in southern hemisphere (SH), leading to different spatio‐temporal pattern of ozone anomalies. Consequently, dominated by the dynamical processes, equatorial eruption leads to ozone loss in tropics and increase in midlatitudes, while both northern extratropical summer and winter eruptions trigger ozone decrease in NH and increase in SH.

Marine microbial community taxonomic and functional indicators to volcanic and anthropogenic stressors in Deception Island, Antarctica

In recent years, the growth in Antarctic tourism has stimulated research on the anthropogenic impacts on the region, boosted by advances in OMIC technologies applied to polar microbial communities. This study aimed to assess the human impacts on marine prokaryotic and viral communities of Deception Island by identifying potential taxonomic, functional, and resistome indicators of both anthropogenic and natural/volcanic pressures. Proteobacteria, Bacteroidetes, and Actinobacteria were the dominant phyla, with notable variations attributed to volcanic activity and anthropogenic pressure. The abundance of Euryarchaeota in regions with increased volcanic activity underlines their adaptability to extreme conditions. Their mercury resistance coupled with their ability to cope with toxic heavy metals is a critical component in managing volcanic mercury concentrations. Actinobacteria, Cyanobacteria, Planctomycetes, and Synergistetes showed distinctive abundance patterns with potential ecological implications related to volcanic environments. Functional analyses revealed the enrichment of functions associated with metal-based, hydrocarbon degradation, and nitrogen metabolism. Submarine volcanic vents contributed significantly to the shape of functional diversity. Identification of specific functions related to nosocomial infections and gastroenteritis highlights the impact of anthropogenic activities on functional traits. Antibiotic resistance genes (ARGs) showed nuanced patterns influenced by both anthropogenic pressure and volcanic activity. Actinobacteria were correlated with increased ARG abundance, which was enhanced by wastewater disposal. Remarkably, Fumarole Bay showed an increased prevalence of certain ARGs, despite a lower anthropogenic impact, suggesting a unique selective pressure induced by volcanic activity. The responsiveness of these indicators to varying levels of pressure characterizes them as valuable tools for assessing and mitigating anthropogenic impacts on the marine waters of Deception Island.

Long-range transport of air pollutants increases the concentration of hazardous components of PM2.5 in northern South America

Abstract. Long-range transport (LRT) of air pollutants from a range of sources can substantially enhance background pollution levels, especially in urbanized regions, which can exacerbate high-pollution episodes. In the Aburrá Valley (AV), Colombia, and other cities in northern South America, biomass burning (BB), dust, and volcanic degassing have been identified as sources of long-range aerosol transport. However, the impact of these sources on air quality and the characterization of these sources have yet to be thoroughly studied. This work investigates the influence of these sources on the chemical composition of PM2.5 during annual and intra-annual high-load aerosol events in the AV. We identified, tracked, and meteorologically characterized LRT events and evaluated their influence on PM2.5 concentration and chemical composition. We found that the LRT of aerosols from BB, dust, and volcanic degassing influenced approximately 13 %, 8 %, and 13 % of days in the year, respectively. We applied the positive-matrix-factorization (PMF) statistical model to quantify PM2.5 concentrations and chemical compositions for the different LRT event types (e.g., BB). For BB events, we identified large contributions from organic carbon (OC1 and OC2), F−, and secondary aerosol tracers (SO42- and NO3-). For dust LRT events, crustal mineral components, along with Ti and Ca, were the primary contributors to aerosol composition, while SO42-, Na, Al, and Ca were the primary contributors during volcanic events. The concentrations of some ions and toxic heavy metals (Cr, Mn, Cd, and Ni) were also elevated during BB and volcanic-degassing events. BB contributed the most to PM2.5 levels during the LRT events (∼11 µg m−3), while contributions from aerosols arising from dust and volcanic events were also substantial (<7 µg m−3). Our study identifies the Orinoco and the Middle Magdalena Valley as sizable sources of BB aerosols and Nevado del Ruiz as a source of volcanic aerosols. Additionally, we found that African dust reached the Andean region via the Caribbean route. As a result, we identify the need for future chemical-transport modeling studies in the region and new support strategies to manage internal and external pollution sources that degrade air quality in the AV and the surrounding region.

Long-term (2010–2021) lidar observations of stratospheric aerosols in Wuhan, China

Abstract. This study analyzes the vertical distribution, optical properties, radiative forcing, and several perturbation events of stratospheric aerosols using observations from a ground-based polarization lidar in Wuhan (30.5° N, 114.4° E) from 2010 to 2021. The background stratospheric aerosol optical depth (sAOD) was 0.0044 ± 0.0019 at 532 nm, as calculated during a stratosphere-quiescent period from January 2013 to August 2017. In addition, several cases of volcanic aerosol and wildfire-induced smoke were observed. Volcanic aerosols from the Nabro (2011) and Raikoke (2019) eruptions (both in boreal summer) increased the sAOD to 2.9 times the background level. Tracers of smoke from the Canadian wildfire in the summer of 2017 were observed twice, at 19–21 km on 14–17 September and at 20–23 km on 28–31 October, with a plume-isolated aerosol optical depth (AOD) of 0.002–0.010 and a particle linear depolarization ratio δp of 0.14–0.18, indicating the dominance of non-aged smoke particles. During these summertime events, the injected stratospheric aerosols were captured by the large-scale Asian monsoon anticyclone (AMA), confining the transport pathway to mid-latitude Asia. On 8–9 November 2020, smoke plumes originating from the California wildfire in October 2020 appeared at 16–17 km, with a mean δp of 0.13. Regarding seasonal variation, the sAOD in the cold half-year (0.0054) is 69 % larger than in the warm half-year (0.0032) due to stronger meridional transport of stratospheric aerosols from the tropics to middle latitudes. The stratospheric radiative forcing was −0.11 W m−2 during the stratosphere-quiescent period and increased to −0.31 W m−2 when volcanic aerosols were largely injected. These findings contribute to our understanding of the sources and transport patterns of stratospheric aerosols over mid-latitude Asia and serve as an important database for the validation of model outputs.

On the рossibility of multichannel optical backscattering sondes for joint balloon and lidar studies of the aerosol composition of the middle atmosphere

Aerosol backscattering sondes in the practice of aerological sounding, along with lidar observations, are used at night to study and monitor polar stratospheric clouds, tropospheric and stratospheric aerosol, cirrus clouds, pyroconvection, volcanic aerosol, as well as to verify remote methods and means of ground-based and satellite-based aerosol observations. For aerosol sondes, a simple two-wave measurement technique is used, which makes it possible to diagnose changes in aerosol composition by color index. The possibilities of the two-wave technique have limitations, which are discussed in this article. Aerological sounding combined with lidar observations expands the wavelength range for multi-wavelength studies, and direct measurements of atmospheric temperature increase the accuracy of aerosol sensing. The paper considers the application of 3 or more wavelenght techniques. Data from probe measurements using wavelengths of 470, 528, 850 and 940 nm and lidar sensing at wavelengths of 355 and 532 nm are presented.

Mildly explosive eruptions at Martian low-shield volcanoes

AbstractOngoing acquisition of Martian surface imagery constantly provides new opportunities to reveal previously undiscovered small-scale volcanic landforms, yielding critical insights into volcanic processes, and challenging existing inferences. Here, using the most recent, high-resolution topographical data, we mapped the accumulation of pyroclastic deposits occurring along the margins of several volcanic vents. They share morphological similarities with terrestrial volcanic deposits attributed to low-intensity lava fountaining occurring during mild explosive activity. Our identified, explosive volcanic deposits are associated with late Amazonian volcanic activity in Tharsis. The identification of these very recent (<100 Ma) deposits across the entire Tharsis volcanic province needs reconciling with our current view of the evolution of explosive volcanism on Mars. We contend that these small volume landforms, produced by mildly explosive volcanic activity, need to be considered in models surrounding planet-scale magmatic evolution and atmospheric volatile budgets.

Study of the Use of Oxygenated Water as a Non-Toxic Molecule Model for Catalytic Testing of Pozzolana-PN and Iron-Based NOx Reducing Catalysts

During previous catalytic tests on the reducing power of NOx catalysts based on pozzolana and PN-black citric acid polymer, it was found that the use of the NO<sub>2</sub> model molecule poses a significant health and environmental risk. Thus, a project was launched to find another, much less harmful model molecule. Hydrogen peroxide H<sub>2</sub>O<sub>2</sub> was chosen, a molecule naturally secreted by the body to prevent pigment synthesis, with disinfectant, antiseptic and whitening properties widely used in various activities, including cosmetics. Consequently, catalytic tests of NOx-reducing power using hydrogen peroxide H<sub>2</sub>O<sub>2</sub> as a model molecule were carried out on two catalysts based on pozzolana and PN-black polymer of citric acid, PNP-Fe-water-15% and PNP-Fe-ethanol-15%, differing in the solvent used during their syntheses according to a procedure detailed in the bibliography and this manuscript. Pozzolana is a volcanic rock widespread in the volcanic mountains in the Vakinankaratra region of Madagascar. Its use as a support for catalysts based on PN-black polymer of citric acid and Iron-Fe enabled us to synthesize various catalysts, the characteristics and synthesis methods of which are detailed in this manuscript. In short, the catalytic test with hydrogen peroxide was conclusive, enabling a pragmatic comparison of the two catalysts tested, with the result that the catalyst synthesized with water PNP-Fe-water-15% is more active than the catalyst synthesized with ethanol PNP-Fe-ethanol-15%. This is due to the quality and difference in dispersion of the PN-black polymer molecules depending on the solvent used, which can have an impact on the nature of the catalyst surfaces and certain characteristics such as porosity. This dispersion is confirmed and viewed using an optical microscope to visualize the surface of a catalyst grain. Kinetic results from two proposed mechanisms for the reduction of H<sub>2</sub>O<sub>2</sub> hydrogen peroxide molecules using PNP-Fe catalysts also confirmed not only the proposed mechanisms, but also the higher activity of PNP-Fe catalysts synthesized with water, whose kinetic constants are much higher than those synthesized with ethanol.

Quantifying the internal and external drivers of Southeast Asian rainfall extremes on decadal timescales

Rainfall over mainland Southeast Asia experiences variability on seasonal to decadal timescales in response to a multitude of climate phenomena. Historical records and paleoclimate archives that span the last millennium reveal extreme multi-year rainfall variations that significantly affected the societies of mainland Southeast Asia. Here we utilize the Community Earth System Model Last Millennium Ensemble (CESM-LME) to quantify the contributions of internal and external drivers to decadal-scale rainfall extremes in the Southeast Asia region. We find that internal variability was dominant in driving both Southeast Asian drought and pluvial extremes on decadal timescales although external forcing impacts are also detectable. Specifically, rainfall extremes are more sensitive to Pacific Ocean internal variability than the state of the Indian Ocean. This discrepancy is greater for droughts than pluvials which we suggest is attributable to external forcing impacts that counteract the forced Indian Ocean teleconnections to Southeast Asia. Volcanic aerosols, the most effective radiative forcing during the last millennium, contributed to both the Ming Dynasty Drought (1637–1643) and the Strange Parallels Drought (1756–1768). From the Medieval Climate Anomaly to the Little Ice Age, we observe a shift in Indo-Pacific teleconnection strength to Southeast Asia consistent with enhanced volcanism during the latter interval. This work not only highlights asymmetries in the drivers of rainfall extremes but also presents a framework for quantifying multivariate drivers of decadal-scale variability and hydroclimatic extremes.

Contrasting Chlorine Chemistry on Volcanic and Wildfire Aerosols in the Southern Mid‐Latitude Lower Stratosphere

Contrasting Chlorine Chemistry on Volcanic and Wildfire Aerosols in the Southern Mid‐Latitude Lower Stratosphere

HSW-V v1.0: localized injections of interactive volcanic aerosols and their climate impacts in a simple general circulation model

HSW-V v1.0: localized injections of interactive volcanic aerosols and their climate impacts in a simple general circulation model

Dwindling Effective Radiative Forcing of Large Volcanic Eruption: The Compensation Role of Ocean Latent Heat Flux

AbstractClimatic impacts of historical volcanism are principally tied to the eruption size, while observation versus model discrepancies have been commonly attributed to the uncertainties in paleo‐reconstruction or malpresentation of volcanic aerosols in models. Here we present convergent evidence for significant compensation effect of ocean latent heat (LH) in balancing the tropical volcanic‐induced heat loss, by introducing an effective perturbation ratio which is found to decrease with increasing eruption magnitude. Four LH compensation hot spots overlapping with the trade wind regions are identified, together with three western boundary currents regions with intensified LH loss. Comparison between the 1258 Samalas and 1452 Unidentified eruptions suggests considerable modulation of the concurring El Nino‐Southern Oscillation on LH anomaly, which is further verified by CESM large ensemble sensitivity experiments. This study depicts how the interplay between the ocean and the atmosphere could contribute to the overall resilience of the climate system in the face of volcanic disturbances.