Volcanic Fumes Research Articles

Volcanic fumes warn of imminent eruptions

Volcanic fumes warn of imminent eruptions

Continuous monitoring of Hawaiian volcanoes with thermal cameras

Continuously operating thermal cameras are becoming more common around the world for volcano monitoring, and offer distinct advantages over conventional visual webcams for observing volcanic activity. Thermal cameras can sometimes “see” through volcanic fume that obscures views to visual webcams and the naked eye, and often provide a much clearer view of the extent of high temperature areas and activity levels. We describe a thermal camera network recently installed by the Hawaiian Volcano Observatory to monitor Kīlauea’s summit and east rift zone eruptions (at Halema‘uma‘u and Pu‘u ‘Ō‘ō craters, respectively) and to keep watch on Mauna Loa’s summit caldera. The cameras are long-wave, temperature-calibrated models protected in custom enclosures, and often positioned on crater rims close to active vents. Images are transmitted back to the observatory in real-time, and numerous Matlab scripts manage the data and provide automated analyses and alarms. The cameras have greatly improved HVO’s observations of surface eruptive activity, which includes highly dynamic lava lake activity at Halema‘uma‘u, major disruptions to Pu‘u ‘Ō‘ō crater and several fissure eruptions.

Les sources de nanoparticules

Nanoparticles are defined as particles with at least one spatial dimension of less than 100 nm. This characteristic of nanoparticles is related to the fact that the majority of its atoms are on its surface. This gives the nanoparticle a strong exchange surface (surface-specific) that leads to particular physical and chemical properties. These properties can lead to specific but poorly understood biological effects if they come in contact with living objects. There are a variety of sources of nanoparticles: natural nanoparticles (as produced by volcanic fumes), those produced unintentionally by humans (diesel exhaust particles or particles from welding fumes), and those produced intentionally for new properties (manufactured nanoparticles). In this article, we will discuss these different kinds of nanoparticles.

Temporal variability in SO2 exposures at Hawai’i Volcanoes National Park, USA

Sulfur dioxide measured at the Visitor’s Center of Hawai’i Volcanoes National Park, USA exhibits seasonal and diurnal patterns and is sensitive to rainfall, but the relationship between wind direction and SO2 is too inconsistent to support deterministic predictions of hourly SO2 based on hourly wind direction. Although SO2 at the Visitor Center has usually been below regulatory levels, high SO2 levels and adverse health effects remain a concern. This investigation identified patterns in hourly SO2 based on wind direction, time of day, month, and rainfall occurrence using 4 years of hourly data. Empirical probabilities were investigated using a Bayesian approach. Winds from the volcanic vents were rare, but when they did occur SO2 was elevated about half of the time. Conversely, half of the hours with elevated SO2 occurred when volcanic vents were not directly upwind. Episodes of elevated SO2 tended to occur during the months of November–March and between 8:00 a.m. and 5:00 p.m. Rainfall was associated with a marked reduction in SO2 (29–81% depending on wind direction). Individuals that wish to avoid exposure to volcanic fumes can take these patterns into account.

Vegetation biomass change of the Bosoh Peninsula: Impacted by the volcano fumes from the Miyakejima

Since the 2001 eruption, the volcanic fumes from the Oyama of Miyakejima Island, located approximately 200 km southwest from the mainland of Japan, have affected the vegetation health and biomass of the Tokyo metropolitan area. In this study, we evaluated the potential for measuring/mapping relative forest damage/recovery in forests in the Bosoh Peninsula, Chiba Prefecture, Japan, using LANDSAT Enhanced Thematic Mapper data and ASTER Level-1B data. The simple ratio which is derived from the near-infrared and red reflective response was found to correlate well with ground-based measurements of forest damage caused by continuous SO 2 contained in the volcanic fumes. Accumulated data by the synchronized field campaign observation of the Japanese cedar field spectra and by satellite analysis indicates the following interesting features: (1) regional differences of SO 2 levels in the forestal area can be estimated by the simple spectrum ratio of the near-infrared and red bands of multispectral satellite data; (2) time-series images using the simple ratios indicated the location of still damaged and recovered forests between the 2001 eruption and 2003; (3) if the vegetations under study are homogeneous single-species with a similar leaf area index and a similar age, the simple ratio was useful to evaluate vegetation damage or recovery among individual forests throughout many of the forests in the Bosoh Peninsula; (4) the damage level of the Tokyo Bay side was found to be consistently higher than the Pacific Ocean side of the peninsula. This obvious difference is likely caused, not only by SO 2 from Miyakejima Island, but also by long term and chronic discharged gas from heavy industrial complexes.

Effect of volcanic fumes from Mt. Oyama, Miyakejima Island, on atmospheric deposition, soil solution, and soil properties in Kumagaya, Central Japan

Mt. Oyama, a volcano in Miyakejima Island, became active at the end of June 2000 and began emitting volcanic fumes with a high amount of sulfur dioxide (SO2) at the end of August 2000. Emission of volcanic fumes was still observed in August 2002. We aimed at analyzing the soil properties in Kumagaya in relation to the effect of the volcanic fumes from Mt. Oyama. A soil survey was conducted in a deciduous secondary forest in Kumagaya, Saitama Prefecture, Japan in September 2001, and the physical and chemical properties of the soil were analyzed. The soil in the research plot consisted of volcanic ash soil. However, the properties were markedly different between the topsoil and subsoil. For example, the base saturation values in the A and Bwl horizons were very low, 1.7 and 0.85%, respectively, while the value in the Bw2 horizon was 29%. The soils in the A and Bw1 horizons displayed a considerable anion exchange capacity (AEC) under the field conditions, and the amount of exchangeable sulfate (SO4 2−) accounted for 37% of the AEC in the A horizon. The AEC of the A horizon was considered to have brought about a delay in the changes in the SO4 2− concentration in the soil solution at the depth of 10 cm compared to the changes in the SO4 2− concentration in the throughfall (TF). One of the major features of the soil in the research plot was that it had already adsorbed a large amount of SO4 2− compared with the annual deposition load of SO4 2− from the atmosphere; the ratio of the adsorbed SO4 2− pool to the annual SO4 2− deposition was approximately 60 in the Bw1 horizon. Therefore, the volcanic fumes with a high amount of SO2 from Mt. Oyama were considered to have exerted a negligible effect on the soil properties in the research plot, whereas the fumes affected the properties of atmospheric deposition and upper soil solution in the research plot.

Effect of volcanic fumes from Mt. Oyama, Miyakejima Island, on atmospheric deposition, soil solution, and soil properties in Kumagaya, central Japan

The chemical properties of the atmospheric deposition and soil solution were monitored in a deciduous secondary forest in Kumagaya, Saitama Prefecture, Japan, from June 2000 to July 2001. Mt. Oyama, a volcano in Miyakejima Island, became active at the end of June 2000 and has been emitting volcanic fumes with a large amount of sulfur dioxide (SO2) since the end of August 2000, while no fall of volcanic ash occurred in the Kanto District. Therefore, we aimed at analyzing the effect of the fumes from Mt. Oyama on the chemical properties of the atmospheric deposition and soil solution in Kumagaya, focusing on the behavior of sulfate (SO4 2−). The equivalent ratio of non-seasalt SO4 2−} (nss-SO4 2−) to nitrate (NO3 2−) and also nss-SO4 2− to total anions in atmospheric deposition evidently increased, especially from August to December 2000, compared to the period from June to July 2000. On the other hand, the changes in the SO4 2− concentration in the soil solution appeared to be relatively stable but were delayed in the case of atmospheric deposition. The delay was ascribed to the adsorption of SO4 2− on the surface of soil particles, and Oll ligand exchange associated with the adsorption.

PGE in fresh basalt, hydrothermal alteration products, and volcanic incrustations of Kilauea volcano, Hawaii

The concentrations of Os, Ir, Pd, and Au in fresh unaltered Kilauean tholeiite were determined by radiochemical neutron activation analysis. For a suite of 18 samples, averages were: Os = 0.38 ± 0.23, Ir = 0.38 ± 0.14, Pd = 2.40 ± 1.04, and Au = 1.78 ± 0.57 (in ppb with a 1σ SD). Correlations of these metals with Co, Cr, Cu, Ni, and MgO in fresh basalts, and petrographic observations, indicate that Os and Ir are carried mainly in chromite, much of which occurs as inclusions in olivine phenocrysts. Palladium correlations suggest its occurrence partly in olivine and partly in the matrix whereas Au seems to be predominantly a matrix constituent. Altered basalts were analyzed for Ir, Pd, and Au in a suite of 19 samples from five different locations. Minor changes only in either concentrations or element ratios were found for Ir and Pd when fresh and altered rock data were compared. However, Au was consistently enriched in altered relative to fresh rocks. These results imply that Pd and Ir, in contrast to Au, will likely retain their eruptive signatures upon burial in a subaerial eruptive setting. High-temperature sulfate-dominated condensates generate incrustations enriched in Ir, Os, Au, and Pd by approximately 50, 20, 10, and 3×, respectively, relative to fresh rocks. In contrast, low-temperature native sulfur deposits are the most depleted material found in the study with Ir, Pd, and Au lower by factors of 10, 4, and 5 compared with fresh rock averages. The strong enrichments of Os and Ir in the high-temperature suite are attributed mainly to enhanced volatility in highly oxygenated magmatic hydrothermal fluids contaminated by meteoric water near the structural top of volcanic conduits. The relatively smaller Pd enrichment, which is dependent on the chloride content of fluids, implies that PGE partitioning into volcanic fume may fractionate these metals (e.g., Pd versus Ir) relative to host basalt in the eruptive process.

Introduction to Special Section on How Volcanoes Work: Part 2

The special section on “How Volcanoes Work” is a collection of some of the nearly 300 papers presented at the Hawaii Symposium on How Volcanoes Work, held in Hilo in January 1987 [Tilling, 1987a]. The response of the symposium participants to the invitation to submit their papers for consideration in the special section exceeded expectations. In all, more than 70 manuscripts were received, reviewed, and handled following regular JGR editorial procedures.Part 1 of the special section, composed of the papers that were processed and accepted in time to meet the production schedule, was published in the December 1987 issue of the Journal of Geophysical Research‐Solid Earth and Planets [Tilling, 1987a]. Even though part 1 contained only eight papers, it nonetheless provided a representative sampling of the multidisciplinary nature of the investigations undertaken to improve our understanding of volcanic systems. The papers published in part 1 included ground deformation studies on caldera systems [Dzurisin and Yamashita, 1987; Mortensen and Hopkins, 1987], geochemical and observational studies of the lava fountains and of volcanic fume during the 1983–1984 activity of Pu'u 'O'o in Kilauea's east rift zone [Crowe et al., 1987; Head and Wilson, 1987], magmatic crystal stratigraphy and theoretical petrology [Pearce et al., 1987; Russell, 1987], dynamics of active lava lakes [Tilling, 1987b], and seismic evidence for a subcrustal intrusive complex beneath the Island of Oahu, Hawaii [ten Brink and Brocher, 1987].

Trace element geochemistry of volcanic gases and particles from 1983–1984 eruptive episodes of Kilauea Volcano

Compositional data have been obtained for volcanic gases and particles collected from fume emitted at the Pu'u O'o vent on the east rift zone of Kilauea volcano. The samples were collected by pumping fume through a filter pack system consisting of a front stage particulate filter followed by four base‐treated filters (7LiOH). Particles and condensed phases are trapped on the particulate filter, and acidic gases are collected on the treated filters. The filters are analyzed for 30 elements by instrumental neutron activation analysis. Fume samples were collected from the Pu'u O'o vent for two eruptive episodes: (1) 7 days after episode 11 (cooling vent samples) and (2) the waning stage of episode 13 (active vent samples). Additional samples were collected by aircraft from the gas plume released during the lava fountaining phase of episode 17 (aircraft samples). Element concentrations in the vent gases were > 104 μg m−3 for S, Cl, and F. Enrichment factors (EFs) for the volcanic fume versus the source magma were calculated using the volatile element Br as the reference element for normalization and the U.S. Geological Survey standard BHVO‐1 as the magma standard. This removes the ash dilution effect obtained by using an ash constituent (Al, Sc, or Mg) as the reference element. Bromine‐normalized EFs (× 105) range from 101 to 102 for Na, K, and Cu; 102 to 105 for Zn, W, Sb, In, Ir, Ag, F, and As; and > 105 for Au, Cd, Re, Cl, Se, and S. The highest enrichment factors are for aircraft samples collected during the most gas‐rich phase of an eruption cycle. Metal and volatile‐element data form two groups: (1) elements showing little or no variation in abundance ratios with sample type (group 1: Cl, Br, and Re) and (2) elements that show significant variation in abundance ratios by sample type (group 2: Zn, W, Sb, In, Ir, Au, and Cd). Bivariate plots of elements of the first group versus elements of the second group separate by sample type. The separation corresponds to samples collected during eruptive activity versus samples collected during repose periods. Monitoring trace metal ratios in volcanic fume could provide an additional tool for predicting volcanic eruptions. The F/Cl ratio of cooling vent samples is higher than those of active vent or aircraft samples, and the ratio is inversely correlated with EFs for most volatile metals.

Identification of eruption clouds with the landsat satellites

Landsat satellite images were selected for the analysis of a tephraladen eruption cloud and a volcanic fume cloud. A 35 km long eruption plume from Sakurazima Volcano, Kyushu, Japan was viewed by the satellite on December 2, 1972. Multispectral Scanner (MSS) band 4 was density sliced into eight levels. Grey levels over the tephra-laden cumulus, which had formed at the terminus of the eruption plume, were distinct from most of the nearby cumulus clouds. MSS band 4 is the key band for identifying eruption clouds in overcast volcanic regions.

Mount Etna and the 1971 eruption - The collection and analysis of volcanic gases

A French team, with workers from Centre d’Etudes Nucleaire, Fontenay, Commissariat a l’Energie Atomique, and Centre National des Recherche Scientifique, have conducted numerous missions to Etna in recent years and these will be briefly reviewed (Tazieff, Boulay, Garrand & Maulard 1968; Boutry & Jatteau 1968; Elskens 1969; Tazieff et al. 1969). Pre-1971 missions In 1969, the central crater had many deep explosions (figure 1). Of particular interest was the Bocca Nuova, a small vent, 6 to 7 m in diameter, which displayed vigorous high temperature gas emission. The gases were emitted in gusts with a regular period, and their physical and chemical characteristics were studied. The maximum water content was of the order of 30 to 40 %. The periodic explosions could be correlated with carbon dioxide contents of 40 to 60 %. All the gas samples taken from the Bocca Nuova were heavily contaminated with air, this could be due to either air percolating through the porous superstructure of the volcano into the vent throat, or by air being sucked into the vent via the orifice in between gusts. The latter is supported by measurements of velocity and a film taken of the phenomenon. In 1970, Le Guern & Le Bronec noted that the central crater was in the same state as 1969. Many explosions were taking place at the bottom of the chasm, which at the surface had dimensions of 200 m by 300 m. The ejectamenta accompanying the explosions rarely reached the top lip due to the great depth. The crater was filled with dense volcanic fumes which occasionally cleared, allowing a glimpse of the vertical walls, and by night, to see the explosive activity at the bottom.

The "Alpine" Plants of the Antilles

Although few mountains of the Antilles are over 5000 ft, some of them do possess a distinctive type of vegetation near the summit. Mountains such as Mt. Pelee, the Soufriere of Guadeloupe, or the Soufriere of St. Vincent have been active volcanoes in the present century, and the reduced scanty or restricted vegetation there may be due to past and present volcanic fumes or rapid percolation of water on ashy substrata. The reduced elfin vegetation of other mountains has been attributed to effects of persistent wind, persistent cloud cover, colder temperatures, or saturated soils. Studies of the elfin forest on Pico del Oeste (3050 ft) in Puerto Rico have supplied information on both the environment of the mountain top and the composition of the forest type. After a full year of study it was shown that the rainfall was 453 cm; that clouds enveloped the peak 100 percent of the nighttime hours and 60 percent of daylight hours with the average relative humidity 98.5 percent. Clouds supplied an additional 10 percent to the total rainfall. Wind speed raniged from 8 to 11.1 knots. The average mean temperature was 17.4 degrees C and the soil 18.3 degrees C. Growth patterns of individual plants showed an abundance of long shoot-short shoot stems; dichotomous branching and pagoda branching. Insect damage to leaves was high, reducing the photosynthetic potential of the forest. Fertility was very low as recorded in pollen viability and seed set. THE ISLANDS OF the Lesser Antilles in the Caribbean area possess volcanic cones which range in altitude from the 1950-foot St. Eustatius in the north to the 2749 feet of Mt. Catherine on Grenada in the south,

Weathering of a Quartz Diorite at Marble Point, McMurdo Sound, Antarctica

Methods established by Goldich (1938) in his classic study of rock weathering have been applied with some modifications to analysis of a weathered rock series collected in the Antarctic. Exposures of a finegrained quartz diorite exposed at Marble Point, McMurdo Sound, were selected for study because they appeared to have undergone extensive chemical weathering beyond the effects to be expected in a region of such extreme cold and aridity. The light-gray, well-knit rock is altered in its most weathered form to a rich brown sand with angular particles as small as 0.003 mm. Complete chemical analyses of the rock in six of its weathering stages were obtained, and the trends established by these data were correlated with the mineralogie changes. Contrary to the impressions gained in the field, the bulk chemical and mineralogie composition of this rock has remained constant throughout the observed weathering sequence. There is no substantial change in alumina, combined silica, soda, lime, or potash which are normally sensitive indicators of chemical action. No clay forms in the weathering process. The only appreciable change involving an original constituent of the rock is the progressive oxidation of ferrous iron in pyrrhotite and biotite and the resulting formation of limonite which is responsible for the pronounced difference in color of the physically weathered debris. Seventy per cent of the original ferrous oxide is lost, and 45 per cent of total iron oxide is leached from the rock. Small amounts of halite deposited by evaporation of sea spray and native sulfur, presumably derived from volcanic fumes of Mt. Erebus, are found in the more-weathered materials at Marble Point. Their abundance relates to weathering only in that the disintegrated rock is physically more favorable to accumulation of these exotic substances. Oxidation of the native sulfur has contributed acid to the surface debris and thereby promoted rapid decomposition of pyrrhotite in the fresh rock and the pronounced iron staining in the weathered outcrops. The maximum volumetric changes caused by oxidation and hydration of the original minerals is negligible, and it is concluded that the mechanism primarily responsible for the observed breakdown of the rock is the combined action of frost-wedging and the crystallization of salt in pores and crevices in the weathering rock. Continuous records of the ambient air temperatures taken at Marble Point during the summers of 1957-58 and 1958-59 suggest that about thirty freeze-thaw cycles affect the site each year. However, on unclouded days rock-surface temperatures are considerably higher than air temperatures, and the number of freeze-thaw cycles in the rocks probably does not correspond to that indicated by air-temperature measurements. This study began as an investigation of what appeared to be a case of strong chemical weathering in the Antarctic and has ended in providing quantitative proof of the predominance of physical processes, a predominance commonly accepted on qualitative grounds.