the use of 7 lioh impregnated filters for the collection of acidic gases and analysis by instrumental neutron activation analysis a simple system was designed using7lioh impregnated filters to collect acidic gases from ambient air and from highly concentrated volcanic plumes or gas streams these filters were developed for analysis using instrumental neutron activation analysis but other analytical techniques could be used as well the sampling system was designed to use a series of 1 3 m7lioh impregnated filters to collect high concentrations of acidic gases found in gas plumes of active volcanoes the filters are quantitative for so2 and the halide acids when sufficient base is present to neutralize the acidic species extremely high concentrations of so2 may not be collected quantitatively since so2 is a relatively weak lewis acid compared to the halide acids the acidic oxides of sb as and se were also collected quantitatively a particle filter preceded the impregnated filters in order to remove particles from the fumes this system has proven effective under difficult sampling conditions and since it is portable and light weight it could be used for many volcanological applications where high levels of acidic gaseous phase species need to be collected

emission of bromine and iodine from mount etna volcano 1 constraining fluxes of volcanic bromine and iodine to the atmosphere is important given the significant role these species play in ozone depletion however very few such measurements have been made hitherto such that global volcanic fluxes are poorly constrained here we extend the data set of volcanic br and i degassing by reporting the first measurements of bromine and iodine emissions from mount etna these data were obtained using filter packs and contemporaneous ultraviolet spectroscopic so2 flux measurements resulting in time averaged emission rates of 0 7 kt yr 1 and 0 01 kt yr 1 for br and i respectively from april to october 2004 from which we estimate global br and i fluxes of order 13 range 3 40 and 0 11 range 0 04 6 6 kt yr 1 observed changes in plume composition highlight the coherent geochemical behavior of hcl hf hbr and hi during magmatic degassing and strong fractionation of these species with respect to so2

sulphur dioxide particle and elemental emissions from mount etna italy during july 1987 sulphur dioxide emission rates were measured at mount etna italy during july 1987 while the volcano was undergoing relatively quiet activity the so2 flux averaged 930 587 1 mg d excluding 19 july when the flux was 3200 1730 1 mg d rising magma and or an influx of less degassed magma could explain the increased so2 flux the high so2 flux did not correlate with changes in observed volcanic activity this suggests that so2 monitoring may be useful as an indicator of shallow magmatic activity but not as a predictor of future eruptions of mount etna

trace element degassing and enrichment in the eruptive plume of the 2000 eruption of hekla volcano iceland during its last eruption in february 2000 hekla volcano iceland emitted a sub plinian plume that was condensed and scavenged down to the ground by heavy snowstorms offering the unique opportunity to study the chemistry of the gaseous plume released during highly explosive eruptions in this paper we present results on trace element and minor volatile species sulfates chlorides and fluorides concentrations in snow samples collected shortly after the beginning of the eruption the goal of this study is to better constrain the degassing and mobility of trace elements in gaseous emissions trace element volatility at hekla is quantified by means of enrichment factors ef relative to be well known volatile trace elements e g transition metals heavy metals and metalloids are considerably enriched in the volcanic plume of hekla their abundances are governed by the primary magmatic degassing of sulfate and or halide compounds which are gaseous at magmatic temperature their volatility is however slightly lower than in basaltic systems most likely because of the lower magma temperature and higher magma viscosity at hekla more surprisingly refractory elements e g ree th ba and y are also significantly enriched in the eruptive plume of hekla where their apparent volatility is two orders of magnitude higher than in mafic systems in addition ree patterns normalized to the hekla 2000 lava composition show a significant enrichment of hree over lree suggesting the presence of ree fluorides in the volcanic plume such enrichments in the most refractory elements and ree fractionation are difficult to reconcile with primary degassing processes since ree fluorides are not gaseous at magma temperature ree enrichments at hekla could be attributed to incongruent dissolution of tephra grains at low temperature by f rich volcanic gases and aerosols within the eruptive plume this view is supported by both leaching experiments performed on hekla tephra and thermodynamic considerations on ree mobility in hydrothermal fluids and modeling of glass dissolution in f rich aqueous solutions tephra dissolution may also explain the observed enrichments in other refractory elements e g th y and ba and could contribute to the degassing mass balance of some volatile trace elements provided they are mobile in f rich fluids it thus appears that both primary magmatic degassing and secondary tephra dissolution processes govern the chemistry of eruptive plumes released during explosive eruptions

gas aerosol ash interaction in volcanic plumes new insights from surface analyses of fine ash particles the reactions occurring between gases aerosols and silicate ash particles in volcanic eruption plumes remain poorly understood despite the fact that they are at the origin of a range of volcanic environmental atmospheric and health effects in this study we apply x ray photoelectron spectroscopy xps a surface sensitive technique to determine the chemical composition of the nearsurface region 2 10 nm of nine ash samples collected from eight volcanoes in addition atomic force microscopy afm is used to image the nanometer scale surface structure of individual ash particles isolated from three samples we demonstrate that rapid acid dissolution of ash occurs within eruption plumes this process is favoured by the presence of fluoride and is believed to supply the cations involved in the deposition of sulphate and halide salts onto ash afm imaging also has permitted the detection of extremely thin 10 nm coatings on the surface of ash this material is probably composed of soluble sulphate and halide salts mixed with sparingly soluble fluoride compounds the surface approach developed here offers promising aspects for better appraising the role of gas aerosol ash interaction in dictating the ability of ash to act as sinks for various volcanic and atmospheric chemical species as well as sources for others c 2007 elsevier b v all rights reserved

co2 output and δ13c co2 from mount etna as indicators of degassing of shallow asthenosphere an estimated average co2 output from etna s summit craters in the range of 13 3 mt a has recently been determined from the measured so2 output and measured co2 so2 molar ratios to this amount the co2 output emitted diffusely from the soil 1 mt a and the amount of co2 dissolved in etna s aquifers 0 25 mt a must be added data on the solubility of co2 in etnean magmas at high temperature and pressure allow the volume of magma involved in the release of such an amount of this gas to be estimated this volume of magma 0 7 km3 a is approximately 20 times greater than the volume of magma erupted annually during the period 1971 1995 on the basis of c isotopic data of co2 collected in the etna area and of new hypotheses on the source of mediterranean magmas significant contributions of co2 from non magmatic sources to the total output from etna are unlikely such large outputs of co2 and also of so2 from etna could be due to an anomalously shallow asthenosphere beneath the volcano that allows a continuous escape of gases toward the surface even without migration of magma

composition resolved size distributions of volcanic aerosols in the mt etna plumes 1 particle size distributions for soluble and insoluble species in mt etna s summit plumes were measured across an extended size range 10 nm d 100 m using a combination of techniques automated scanning electron microscopy qemscan was used to chemically analyze many thousands of insoluble particles collected on pumped filters allowing the relationships between particle size shape and composition to be investigated the size distribution of fine silicate particles d 10 m was found to be lognormal consistent with formation by bursting of gas bubbles at the surface of the magma the compositions of fine silicate particles were found to vary between magmatic and nearly pure silica this is consistent with depletion of metal ions by reactions in the acidic environment of the gas plume and vent measurements of the size shape and composition of fine silicate particles may potentially offer insights into preemission synemission and postemission processes the mass flux of fine silicate particles from mt etna released during noneruptive volcanic degassing in 2004 and 2005 was estimated to be 7000 kg d 1 analysis of particles in the range 0 1 d m 100 by ion chromatography shows that there are persistent differences in the size distributions of sulfate aerosols between the two main summit plumes analysis of particles in the range 0 01 m d 0 1 m by scanning transmission electron microscopy stem shows that there are significant levels of nanoparticles in the mt etna plumes although their compositions remain uncertain

dynamics of diffuse carbon dioxide emissions from cumbre vieja volcano la palma canary islands we report herein the results of 13 soil co2 efflux surveys at cumbre vieja volcano la palma island the most active basaltic volcano in the canary islands the co2 efflux measurements were undertaken using the accumulation chamber method between 2001 and 2013 to constrain the total co2 output from the studied area and to evaluate occasional co2 efflux surveys as a volcanic surveillance tool for cumbre vieja soil co2 efflux values ranged from non detectable up to 2442 g m 2 days 1 with the highest values observed in the south where the last volcanic eruption took place teneguia 1971 isotopic analyses of soil gas carbon dioxide suggest an organic origin as the main contribution to the co2 efflux with a very small magmatic gas component observed at the southern part of the volcano total biogenic and magmatic combined co2 emission rates showed a high temporal variability ranging between 320 and 1544 t days 1 and averaging 1147 t days 1 over the 220 km2 region two significant increases in the co2 emission observed in 2011 and 2013 were likely caused by an enhanced magmatic endogenous contribution revealed by significant changes in the 3he 4he ratio in a co2 rich cold spring the relatively stable emission rate presented in this work defines the background co2 emission range for cumbre vieja during a volcanic quiescence period

mt etna sulfur dioxide flux monitoring using aster tir data and atmospheric observations this work is aimed at estimating the sulfur dioxide emission of mt etna volcano sicily italy using the thermal infrared images remotely sensed by the advanced spaceborne thermal emission and reflection radiometer aster a new procedure named fun is presented based on approximating functions which represent the atmospheric terms of the radiative transfer equation transmittance up welling and down welling radiances the parameters of the approximating functions have been computed through the modtran simulations performed using atmospheric monthly mean profiles measured at trapani 1989 2003 trapani wmo station 16429 is located at the western tip of sicily and is the closest station to mt etna volcano with these functions modtran is no longer necessary to compute the so2 abundance in the plume emitted from mt etna and seen by aster only an atmospheric radiosounding and a digital elevation model dem registered to the aster image are required this new procedure is compared with the known look up tables lut procedure proposed by other authors an interesting aspect of the fun procedure derives from its combined use with a split window sw algorithm in this case only radiosounding is required to compute the so2 map the fun procedure presented in this paper is a rapid simple and accurate means of generating so2 map estimates from the aster view of mt etna the proposed scheme can easily be adapted to another sensor and another volcano in this paper the results from two aster images 19 july 2003 and 29 july 2001 are presented in

mobility and fluxes of major minor and trace metals during basalt weathering and groundwater transport at mt etna volcano sicily abstract the concentrations and fluxes of major minor and trace metals were determined in 53 samples of groundwaters from around mt etna in order to evaluate the conditions and extent of alkali basalt weathering by waters enriched in magma derived co 2 and the contribution of aqueous transport to the overall metal discharge of the volcano we show that gaseous input of magmatic volatile metals into the etnean aquifer is small or negligible being limited by cooling of the rising fluids basalt leaching by weakly acidic co 2 charged water is the overwhelming source of metals and appears to be more extensive in two sectors of the s sw paterno and e zafferana volcano flanks where out flowing groundwaters are the richest in metals and bicarbonate of magmatic origin thermodynamic modeling of the results allows to evaluate the relative mobility and chemical speciation of various elements during their partitioning between solid and liquid phases through the weathering process the facts that rock forming minerals and groundmass dissolve at different rates and secondary minerals are formed are taken into account at mt etna poorly mobile elements al th fe are preferentially retained in the solid residue of weathering while alkalis alkaline earth and oxo anion forming elements as se sb mo are more mobile and released to the aqueous system transition metals display an intermediate behavior and are strongly dependent on either the redox conditions mn cr v or solid surface related processes v zn cu the fluxes of metals discharged by the volcanic aquifer of etna range from 7 0 10 3 t a th to 7 3 10 4 t a na they are comparable in magnitude to the summit crater plume emissions for a series of elements na k ca mg u v li with lithophile affinity but are minor for volatile elements basalt weathering at mt etna also consumes about 2 1 10 5 t a of magma derived carbon dioxide equivalent to ca 7 of contemporaneous crater plume emissions the considerable transport of some metals in etna s aquifer reflects a particularly high chemical erosion rate evaluated at 2 3 10 5 t a enhanced by the initial acidity of magmatic co 2 rich groundwater

the 2004 2005 etna eruption implications for flank deformation and structural behaviour of the volcano the development of the 2004 2005 eruption at etna italy is investigated by means of field surveys to define the current structural state of the volcano in 2004 2005 a fracture swarm associated with three effusive vents propagated downslope from the se summit crater towards the se such a scenario is commonly observed at etna as a pressure increase within the central conduits induces the lateral propagation of most of the dikes downslope nevertheless some unusual features of this eruption slower propagation of fractures lack of explosive activity and seismicity oblique shear along the fractures suggest a more complex triggering mechanism a detailed review of the recent activity at etna enables us to better define this possible mechanism in fact the nw se trending fractures formed in 2004 2005 constitute the southeastern continuation of a n s trending fracture system which started to develop in early 1998 to the east of the summit craters the overall 1998 2005 deformation pattern therefore forms an arcuate feature whose geometry and kinematics are consistent with the head of a shallow flank deformation on the e summit of etna similar deformation patterns have also been observed in analogue models of deforming volcanic cones in this framework the 2004 2005 eruption was possibly induced by a dike resulting from the intersection of this incipient fracture system with the se crater a significant acceleration of this flank deformation may be induced by any magmatic involvement the central conduit of the volcano is presently open constantly buffering any increase in magmatic pressure and any hazardous consequence can be expected to be limited a more hazardous scenario may be considered with a partial or total closing of the central conduit in this case magmatic overpressure within the central conduit may enhance the collapse of the upper eastern flank triggering an explosive eruption associated with a landslide reaching the eastern lower slope of the volcano

volatilization transport and sublimation of metallic and non metallic elements in high temperature gases at merapi volcano indonesia abstract condensates silica tube sublimates and incrustations were sampled from 500 800 c fumaroles and lava samples were collected at merapi volcano indonesia in jan feb 1984 with respect to the magma merapi gases are enriched by factors greater than 105 in se re bi and cd 104 105 in au br in pb and w 103 104 in mo cl cs s sn and ag 102 103 in as zn f and rb and 1 102 in cu k na sb ni ga v fe mn and li the fumaroles are transporting more than 106 grams day g d of s cl and f 104 106 g d of al br zn fe k and mg 103 104 g d of pb as mo mn v w and sr and less than 103 g d of ni cu cr ga sb bi cd li co and u with decreasing temperature 800 500 c there were five sublimate zones found in silica tubes 1 cristobalite and magnetite first deposition of si fe and al 2 k ca sulfate acmite halite sylvite and pyrite maximum deposition of cl na k si s fe mo br al rb cs mn w p ca re ag au and co 3 aphthitalite k na sulfate sphalerite galena and cs k sulfate maximum deposition of zn bi cd se and in higher deposition of pb and sn 4 pb k chloride and na k fe sulfate maximum deposition of pb sn and cu and 5 zn cu and k pb sulfates maximum deposition of pb sn ti as and sb the incrustations surrounding the fumaroles are also chemically zoned bi cd pb w mo zn cu k na v fe and mn are concentrated most in or very close to the vent as expected with cooling atmospheric contamination and dispersion the highly volatile elements br cl as and sb are transported primarily away from high temperature vents ba si p al ca and cr are derived from wall rock reactions incomplete degassing of shallow magma at 915 c is the origin of most of the elements in the merapi volcanic gas although it is partly contaminated by particles or wall rock reactions the metals are transported predominantly as chloride species as the gas cools in the fumarolic environment it becomes saturated with sublimate phases that fractionate from the gas in the order of their equilibrium saturation temperatures devolatilization of a cooling batholith could transport enough acids and metals to a hydrothermal system to play a significant role in forming an ore deposit however sublimation from a high temperature high velocity carrier gas is not efficient enough to form a large ore deposit re se cd and bi could be used as supporting evidence for magmatic fluid transport in an ore deposit

volcanic emissions of metals and halogens from white island new zealand and erebus volcano antarctica determined with chemical traps abstract volcanic emission rates of as sb pb hg se cl and f were determined at erebus volcano antarctica and white island new zealand using chemical traps the trace metal fluxes were determined by combining the species to s ratios in the solutions with so2 emission rates measured by correlation spectrometry at the two volcanoes at erebus volcano fluxes for the metals pb and hg were 2 0 10 4 and 8 1 10 6 kg s 11 respectively fluxes for cl f as sb and se 0 35 0 15 2 5 10 4 1 2 10 5 and 4 5 10 6 kg s 1 respectively agreed within error limits for values determined previously by the lioh impregnated filter method zreda gostynska g kyle p finnegan d prestbo k 1997 volcanic gas emissions from mount erebus and their impact on the antarctic environment journal of geophysical research 102 b7 15039 15055 demonstrating the utility of the chemical trap method a fall in the as s ratio from 7 10 4 in 1997 1999 to 3 10 4 in 2000 at erebus coincided with a change in the frequency and style of eruptive activity that may have been due to injection of magma into the system at white island chemical trap data indicated fluxes of cl 0 90 f 0 0079 pb 2 7 10 4 hg 1 1 10 5 as 1 3 10 4 sb 1 9 10 5 and se 1 5 10 5 kg s 1 samples collected 600 m downwind of the active crater were comparable to samples collected adjacent to the main gas vent showing that this method can still be used at some distance from a degassing vent

airborne measurements of particle and gas emissions from the december 1994 january 1995 eruption of popocatepetl volcano mexico abstract airborne and ground based correlation spectrometer cascade impactor and photoelectric counter together with intake filter probes measurements are described for the volcanic emissions from popocatepetl volcano mexico from december 23 1994 to january 28 1995 measurements of so 2 restarted 48 h after the eruption onset of december 21 1994 maximum sulfur dioxide 4560 t d 1 plus 3 8 10 4 t d 1 of particulate matter were ejected on december 24 1994 the maximum rate of ejection occurred coincidentally with the maximum amplitude of harmonic tremor and the maximum number of seismic type b events sulfur dioxide emission rates ranged from 1790 to 2070 t d 1 december 23 24 1994 afterwards sulfur dioxide emission rates clearly indicated a consistent decline however frequent gas and ash emission puffs exhibited so 2 fluxes reaching values as high as 3060 t d 1 the emission so 2 baseline for the period of study february 1994 january 1995 was about 1000 t d 1 ejection velocity of particulate matter was approximately 270 m s 1 reaching a height of about 2 5 km over the summit the immediate aerosol dispersion area was estimated at 6 0 10 4 km 2 maximum the microscopic structure of particles aerosol and tephra showed a fragile material probably coming from weathered crustal layers x ray fluorescence and neutron activation analysis from the impactor samples found the following elements si al ca s p cl k ni fe ti sc cu zn mn sr cr co y br se ga rb hg and pb morphological analysis shows that ash samples might be from pulverized basaltic rock indicating that the popocatepetl eruption of december 21 1994 was at low temperature the microscopic structure of puff material showed substance aggregates consisted of fragile rock water and adsorbed so 2 these aggregates were observed within water droplets of approximately 1 mm and even larger sulfur transformations in the droplets occurred intensively volcanic ash contained 5 6 of sulfur during the first expulsion hours elemental relative concentrations with respect to al show that both si and s have relative concentrations 1 i e 13 73 and 2 17 respectively in agreement with the photoelectric counter and cospec measurements

2001 flank eruption of the alkali and volatile rich primitive basalt responsible for mount etna s evolution in the last three decades abstract since the early 1970s enhanced eruptive activity of mount etna has been accompanied by selective geochemical changes in erupted lavas among which a gradual increase of alkalis whose origin is still debated here we provide further insight into the origin of this recent evolution based on a detailed study of the chemistry and dissolved volatile content of melt inclusions trapped in olivine crystals of unusual plagioclase poor primitive basalt that was extruded during a highly explosive flank eruption in july august 2001 two types of lava were erupted simultaneously along a n s fracture system trachybasalts from the upper vents 2950 2700 m were simply drained out by fracturing of the central volcanic conduit they are identical to summit crater lavas and contain mg poor olivines fo 70 72 with evolved and volatile poor melt inclusions that represent late stage crystallisation during shallow open conduit degassing in contrast plagioclase poor basalt 80 of total extruded through the lower vents 2550 2100 m derived from lateral dyke intrusion of a more primitive and volatile rich magma across the sedimentary basement this primitive melt is best preserved in rare fo 82 4 80 5 skeletal olivines present in lapilli deposits from the most powerful activities at the 2550 m vent its high dissolved contents of h 2 o 3 4 wt co 2 0 11 to 0 41 wt s 0 32 wt cl 0 16 wt and f 0 094 wt point to its closed system ascent from 400 to 250 mpa 12 to 6 5 km depth b s l however the predominance of euhedral olivine phenocrysts with common reverse zoning cores fo 76 78 and rims fo 78 80 and decrepited inclusions shows that most of the erupted basalt derived from a slightly more evolved crystallizing body of the same magma that was invaded by the uprising primitive melt prior to erupting the few preserved inclusions in these olivines indicate pre eruptive storage of that magma body at about 5 km depth b s l in coherence with seismic data we propose that the 2001 flank eruption resulted from gradual overpressuring of etna s shallow plumbing system due to the influx of volatile rich primitive basalt that may have begun several months in advance we find that this basalt is much richer in alkalis 2 0 wt k 2 o and has higher s cl 2 0 but lower cl k and cl f ratios than all pre 1970s etnean lavas 1 4 wt k 2 o s cl 1 5 as further exemplified by melt inclusions in entrained olivine xenocrysts combining these new observations with previously published data we argue that the 2001 basalt represents a new alkali rich basic end member feeding mt etna only few amount of which had previously been extruded during a 1974 peripheral eruption and more recently during brief paroxysmal summit events over the last three decades this new magma has progressively mixed with and replaced the former k poorer trachybasalts filling the plumbing system leading to extrusion of gradually more primitive and alkali richer lavas its geochemical singularities cannot result from shallow crustal contaminations instead they suggest the involvement of an alkali richer but cl poorer arc type component during recent magma genesis beneath etna

melt inclusions track pre eruption storage and dehydration of magmas at etna at mount etna italy vigorous gas rich eruptions in a d 2001 2002 and 2003 were followed by gas poor eruptions in 2004 2006 and 2007 analyses of volatile co2 h2o s cl f semivolatile cu and involatile nb la elements trapped in olivine hosted melt inclusions from these latest eruptions reveal the effects of the sustained interaction between a percolating gas phase and the stored magma melt inclusion compositions indicate that magmas erupted from 2004 to 2007 were residual from the 2001 2003 eruptions and show significant evolution in the volatile content of the melt these melt inclusion observations and variations in the c s of volcanic gases can be accounted for if melts reequilibrated with co2 rich gases during storage and prior to entrapment as melt inclusions sustained gas percolation caused loss of water and enhancement of co2 in the evolving melt and may strongly influence the behavior of cu which potentially partitions into the gas phase vapor melt interactions during magma storage are important controls on magma evolution at persistently degassing volcanoes

fractionation of families of major minor and trace metals across the melt vapor interface in volcanic exhalations chemical families of metals fractionate systematically as they pass from a silicate melt across the interface with the vapor phase and on into a cooled volcanic plume we measured three groups of metals in a small suite of samples collected on filters from the plumes of kilauea hawaii usa etna sicily and merapi java volcanoes these were the major minor and trace metals of the alkali and alkaline earth families k rb cs ca sr ba a group of ordinarily rare metals cd cu in pb tl that are related by their chalcophile affinities and the radon daughter nuclides 210po 210bi and 210pb the measurements show the range and some details of systematic melt vapor fractionation within and between these groups of metals in the plumes of all three volcanoes the alkali metals are much more abundant than the alkaline earth metals in the kilauea plume the alkali metals are at least six times more abundant than the alkaline earth metals relative to abundances in the melt at etna the factor is at least 300 fractionations within each family are commonly also distinctive in the kilauea plume in addition to the whole alkaline earth family being depleted the heaviest metals of the family sr ba are progressively more depleted than the light metal ca in plumes of fumaroles at merapi k cs ratios were approximately three orders of magnitude smaller than found in other earth materials this may represent the largest observed enrichment of the light ion lithophile lil metals changes in metal ratios were seen through the time of eruption in the plumes of kilauea and etna this may reflect degree of degassing of volatiles with which metals complex from the magma bodies at kilauea the changes in fractionation were seen over about three years fractionation within the alkaline earth family increased and that between the two families decreased over that time all of the ordinarily rare chalcophile metals measured are extremely abundant in volcanic plumes and cd and tl are enriched relative to the others indium is much more abundant in the plume of the hotspot volcano kilauea than in the etna plume probably non hotspot in character it may be a useful indicator of the tapping of deep mantle zones or could aid in the interpretation of reports of pt group metals in exhalations from hot spot volcanoes indium in old glacial ice strata could help assess magnitude and variability of exhalations from hotspot volcanoes in past time strong melt vapor fractionation of the alkali and alkaline earth metals may only be observed in plumes during quiescent degassing of volcanoes when large amounts of ash or spatter undifferentiated lava enter the plume its alkali and alkaline earth metal composition may approach that of the melt ratios among the chalcophile metals may not be much changed by addition of ash because their concentrations in melt are so small and masses of them in any plume may remain dominated by transfer across the melt vapor interface radon daughter nuclides give information about state of volcanic activity at time of sampling the precisely known origins ultratrace detectability decay systematics and wide variations in volatility of these species provide information about residence times degassing and travel histories and identities of melt bodies in volcanic systems

atmospheric sources and sinks of volcanogenic elements in a basaltic volcano etna italy abstract this study reports on the first quantitative assessment of the geochemical cycling of volcanogenic elements from their atmospheric release to their deposition back to the ground etna s emissions and atmospheric depositions were characterised for more than 2 years providing data on major and trace element abundance in both volcanic aerosols and bulk depositions volcanic aerosols were collected from 2004 to 2007 at the summit vents by conventional filtration techniques precipitation was collected from 2006 to 2007 in five rain gauges at various altitudes around the summit craters analytical results for volcanic aerosols showed that the dominant anions were s cl and f and that the most abundant metals were k ca mg al fe and ti 1 5 50 g m 3 minor and trace element concentrations ranged from about 0 001 to 1 g m 3 from such analysis we derived an aerosol mass flux ranging from 3000 to 8000 t a 1 most analysed elements had higher concentrations close to the emission vent confirming the prevailing volcanic contribution to bulk deposition calculated deposition rates were integrated over the whole etna area to provide a first estimate of the total deposition fluxes for several major and trace elements these calculated deposition fluxes ranged from 20 to 80 t a 1 al fe si to 0 01 0 1 t a 1 bi cs sc th tl and u comparison between volcanic emissions and atmospheric deposition showed that the amount of trace elements scavenged from the plume in the surrounding of the volcano ranged from 0 1 to 1 for volatile elements such as as bi cd cs cu tl and from 1 to 5 for refractory elements such as al ba co fe ti th u and v consequently more than 90 of volcanogenic trace elements were dispersed further away and may cause a regional scale impact such a large difference between deposition and emission fluxes at mt etna pointed to relatively high stability and long residence time of aerosols in the plume

total volatile flux from mount etna 1 the total volatile tv flux from mount etna volcano has been characterised for the first time by summing the simultaneously evaluated fluxes of the three main volcanogenic volatiles h2o co2 and so2 so2 flux was determined by routine doas traverse measurements while h2o and co2 were evaluated by scaling multigas sensed h2o so2 and co2 so2 plume ratios to the uv sensed so2 flux the time averaged tv flux from etna is evaluated at 21 000 t day 1 with a large fraction accounted for by h2o 13 000 t day 1 h2o dominates 70 the volatile budget during syn eruptive degassing while co2 and h2o contribute equally to the tv flux during passive degassing the co2 flux was observed to be particularly high prior to the 2006 eruption suggesting that this parameter is a good candidate for eruption prediction at basaltic volcanoes

an oxygen hydrogen sulfur and carbon isotope study of carbonate replacement skarn tin deposits of the dachang tin field china the dachang tin field located in guangxi province of southern china is one of the largest in the world it comprises the changpo bali and longtaoshan carbonate replacement tin deposits and the lamo cu zn skarn deposit these deposits are hosted by devonian carbonate rich sedimentary rocks which have been metamorphosed to calc silicate skarn and marble near the contact of the longxianggei granite calculated delta 18 o sub h 2 o values of the hydrothermal fluids in equilibrium with quartz cassiterite and calcite are 10 6 and 11 6 9 1 to 10 2 and 7 5 to 9 8 per mil respectively measured delta d values of fluid inclusion waters in cassiterite and calcite are 115 and 120 and 73 to 93 per mil respectively the decrease in the calculated delta 18 o sub h 2 o values from 11 6 to 7 5 per mil is attributed to increase in the co 2 content of the hydrothermal fluids the low delta d values of fluid inclusion waters in cassiterite may be the result of decreasing ch 4 co 2 as the originally magmatic fluid migrated from reducing conditions in carbonaceous black shale to oxidizing conditions in pure limestone oxygen and hydrogen isotope data indicate that the hydrothermal fluid was derived from the longxianggei granite variations in delta 13 c and delta 18 o values of calcite in orebodies altered limestone and marble are due to continuous isotopic exchange reaction between magmatic fluid and carbonate rocks at variable water to rock ratios between 300 degrees to 600 degrees c sulfur isotope data indicate that host rocks controlled the variations in sulfur isotope compositions of sulfide minerals in different deposits of the tin field with significant contribution of sulfur from magmatic fluids

volcanic emission of radionuclides and magma dynamics 210pb 210bi and210po the last decay products of the238u series are highly enriched in volcanic plumes relative to the magma composition moreover this enrichment varies over time and from volcano to volcano a model is proposed to describe 8 years of measurements of mt etna gaseous emissions the lead and bismuth coefficients of partition between gaseous and condensed phases in the magma are determined by comparing their concentrations in lava flows and condensated volatiles in the case of volatile radionuclides an escaping time is calculated which appears to be related to the volcanic activity finally it is shown that that magma which is degassing can already be partly degassed it should be considered as a mixture of a few to 50 of deep non degassed magma with a well degassed superficial magma cell

s cl and f degassing as an indicator of volcanic dynamics the 2001 eruption of mount etna 1 the recent eruption of mount etna july 2001 offered the opportunity to analyze magma derived volatiles emitted during pre and syn eruptive phases and to verify whether their composition is affected by changes in volcanic dynamics this paper presents the results of analyses of f cl and s in the volcanic plume collected by filter packs and interprets variations in the composition based on contrasting solubility in magmas a rayleigh type degassing mechanism was used to fit the acquired data and to estimate henry s solubility constant ratios in etnean basalt this model provided insights into the dynamics of the volcano abundances of sulfur and halogens in eruptive plumes may help predict the temporal evolution of an ongoing effusive eruption

variability of alkali and heavy metal fluxes released by mt etna volcano sicily between 1991 and 1995 abstract we regularly collected volcanic gases and aerosols at mt etna volcano over a long period 1991 1995 and measured their chemical composition by icp ms based on these data we present new evidence on the high volatility of both alkali and some heavy metals in contrast both lanthanides and actinides are not produced as significant gaseous compounds at magmatic temperatures and can be used as tracers of spattered materials all metals of each chemical family maintained systematic trends during the study period at both summit craters and effusive vents located in the valle del bove during the 1991 1993 eruption during the eruption we observed high metal enrichments at effusive vents these enrichments seem to be characteristic of the secondary degassing of a magma previously degassed under the summit area lower metal enrichments are recorded in aerosols sampled in summit crater plumes according to the primary degassing type occurring at these vents while a primary degassing type still occurs at both bocca nuova and voragine during the post eruptive period sud est crater exhibits a transition from primary to secondary type according to the variations of the volcanic activity level we confirm that the alkali metals fractionate systematically within their family as they cross the melt vapour interface the heavier members being always more enriched than the lighter ones in aerosols we also show that this fractionation is not related to the volcanic activity and the degassing type but seems to be a significant feature of the alkali family itself estimation of new emanation coefficients for rubidium caesium tin and thallium 0 07 0 15 0 50 and 21 respectively yields annual outputs around 1000 t yr 60 t yr 240 t yr and 1600 t yr respectively mount etna is a very important source of metals injected into the atmosphere contributing to the global volcanic budget about 16 for heavy metals and 19 for alkali metals in eruptive periods and only 2 and 4 respectively in quiet periods

sweet chestnut castanea sativa leaves as a bio indicator of volcanic gas aerosol and ash deposition onto the flanks of mt etna in 2005 2007 sweet chestnut leaves castanea sativa collected from the flanks of mt etna volcano in 2005 2007 were analysed by inductively coupled plasma mass spectrometry to investigate the spatial and temporal variability of element concentrations the aim of this work was to determine whether these leaves are a bio indicator for volcanic gas aerosol and ash deposition and to gain new insights into the environmental effects of quiescent and eruptive volcanic plumes results show a positive correlation between sample variability in the concentration of elements in castanea sativa and enrichment factors of elements in the plume the spatial and temporal variability of chalcophilic elements as cd cu mo tl zn is consistent with prevailing winds transporting eruptive plumes to the south east of the summit resulting in enhanced plume deposition onto the flanks of the volcano similar spatial and temporal variability was found for the halide forming elements cs k rb and intermediate elements al co mn the spatial variability of chalcophilic intermediate and halide forming elements during quiescent periods was diminished relative to eruptive periods and could not be explained by plume deposition in contrast the concentrations of lithophilic elements ba ca mg sr did not show any clear spatial variability even during eruptive periods comparisons between enrichment factors for elements in castanea sativa and literature values for enrichment factors of the volcanic plume groundwater and lichen were made whilst castanea sativa offers insights into the spatial and temporal variability of deposition the species may not be a bio indicator for plume composition due to biological fractionation

metal emissions from kilauea and a suggested revision of the estimated worldwide metal output by quiescent degassing of volcanoes abstract measurements of a large suite of metals pb cd cu zn and several others and sulfur at kilauea volcano over an extended period of time has yielded a detailed record of the atmospheric injection of ordinarily rare metals from this quiescently degassing volcano representative of an important type we have combined the kilauea data with data of recent studies by others emissions from volcanoes in the indonesian arc the large laki eruption of two centuries ago etna estimates of total volcanic emissions of sulfur to form the basis for a new working estimate of the rate of worldwide injection of metals to the atmosphere by volcanoes the new estimate is that volcanoes inject a substantially smaller mass of ordinarily rare metals into the atmosphere than was stated in a widely cited previous estimate j o nriagu a global assessment of natural sources of atmospheric trace metals nature 338 1989 47 49 our estimate which is an upper limit is an annual injection mass of about 10 000 tons of the metals considered versus the earlier estimate of about 23 000 tons also the proportions of the metals are substantially different in our new estimate