novel retrieval of volcanic so2 abundance from ultraviolet spectra projects i firb miur simulazione dei flussi lavici con gli automi cellulari n rbau01rmz4 002 ii sviluppo di sistemi di monitoraggio funded by dipartimento di protezione civile della regione sicilia ingv istituto nazionale di geofisica e vulcanologia sezione di catania italy iii eu funded sixth framework programme project 18354 novac iv leverhulme trust fellowship

plume tracker interactive mapping of volcanic sulfur dioxide emissions with high performance radiative transfer modeling abstract we describe the development of plume tracker an interactive toolkit for the analysis of multispectral thermal infrared observations of volcanic plumes and clouds plume tracker is the successor to map so2 and together these flexible and comprehensive tools have enabled investigators to map sulfur dioxide so 2 emissions from a number of volcanoes with tir data from a variety of airborne and satellite instruments our objective for the development of plume tracker was to improve the computational performance of the retrieval procedures while retaining the accuracy of the retrievals we have achieved a 300 improvement in the benchmark performance of the retrieval procedures through the introduction of innovative data binning and signal reconstruction strategies and improved the accuracy of the retrievals with a new method for evaluating the misfit between model and observed radiance spectra we evaluated the accuracy of plume tracker retrievals with case studies based on modis and airs data acquired over sarychev peak volcano and aster data acquired over kilauea and turrialba volcanoes in the sarychev peak study the airs based estimate of total so 2 mass was 40 lower than the modis based estimate this result was consistent with a 45 reduction in the airs based estimate of plume area relative to the corresponding modis based estimate in addition we found that our airs based estimate agreed with an independent estimate based on a competing retrieval technique within a margin of 20 in the kilauea study the aster based concentration estimates from 21 may 2012 were within 50 of concurrent ground level concentration measurements in the turrialba study the aster based concentration estimates on 21 january 2012 were in exact agreement with so 2 concentrations measured at plume altitude on 1 february 2012

synthesizing multi sensor multi satellite multi decadal datasets for global volcano monitoring abstract owing to practical limitations less than half of earth s 1400 subaerial volcanoes have no ground monitoring and few are monitored consistently earth observing satellite missions provide global and frequent measurements of volcanic activity that are closing these gaps in coverage we compare databases of global satellite detections of ground deformation 1992 2016 so2 emissions 1978 2016 and thermal features 2000 2016 that together include 306 volcanoes each database has limitations in terms of spatial and temporal resolution but each technique contributed 45 86 unique detections of activity that were not detected by other techniques integration of these three databases shows that satellites detected 102 volcanic activities per year before the year 2000 and 103 activities per year after the year 2000 we find that most of the 54 erupting volcanoes without satellite detections are associated with low volcano explosivity index eruptions and note that many of these eruptions 71 97 135 occurred in the earliest decades of remote sensing pre 2000 when detection thresholds were high from 1978 to 2016 we conduct a preliminary analysis of the timing between the onset of satellite detections of deformation n 154 episodes n 71 volcanoes thermal features n 16 544 episodes n 99 volcanoes and so2 emissions n 1495 episodes n 116 volcanoes to eruption start dates we analyze these data in two ways first including all satellite detected volcanic activities associated with an eruption and second by considering only the first satellite detected activity related to eruption in both scenarios we find that deformation is dominantly pre eruptive 47 and 57 whereas available databases of thermal features and so2 emissions utilizing mainly low resolution sensors are dominantly co eruptive 88 and 76 for thermal features 97 and 96 for so2 emissions

multispectral thermal infrared mapping of sulfur dioxide plumes a case study from the east rift zone of kilauea volcano hawaii the synoptic perspective and rapid mode of data acquisition provided by remote sensing are well suited for the study of volcanic so2 plumes in this paper we describe a plume mapping procedure that is based on image data acquired with nasa s airborne thermal infrared multispectral scanner tims and apply the procedure to tims data collected over the east rift zone of kilauea volcano hawaii on september 30 1988 these image data covered the pu u o o and kupaianaha vents and a skylight in the lava tube that was draining the kupaianaha lava pond our estimate of the so2 emission rate from pu u o o 17 20 kg s 1 is roughly twice the average of estimates derived from correlation spectrometer cospec measurements collected 10 days prior to the tims overflight 10 kg s 1 the agreement between the tims and cospec results improves when we compare so2 burden estimates which are relatively independent of wind speed we demonstrate the feasibility of mapping pu u o o scale so2 plumes from space in anticipation of the 1998 launch of the advanced spaceborne thermal emission and reflectance radiometer aster

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

daily monitoring of ecuadorian volcanic degassing from space we present daily measurements of sulfur dioxide so2 emissions from active volcanoes in ecuador and southern colombia between september 2004 and september 2006 derived from the ozone monitoring instrument omi on nasa s eos aura satellite omi is an ultraviolet visible spectrometer with an unprecedented combination of spatial and spectral resolution and global coverage that permits daily measurements of passive volcanic degassing from space we use non interactive processing methods to automatically extract daily so2 burdens and information on so2 sources from the omi datastream maps of monthly average so2 vertical columns retrieved by omi over ecuador and s colombia are also used to illustrate variations in regional so2 loading and to pinpoint sources the dense concentration of active volcanoes in ecuador provides a stringent test of omi s ability to distinguish so2 from multiple emitting sources our analysis reveals that tungurahua reventador and galeras were responsible for the bulk of the so2 emissions in the region in the timeframe of our study with no significant so2 discharge detected from sangay at galeras and reventador we conclude that omi can detect variations in so2 release related to cycles of conduit sealing and degassing which are a critical factor in hazard assessment the omi so2 data for reventador are the most extensive sequence of degassing measurements available for this remote volcano which dominated regional so2 production in june august 2005 at tungurahua the omi measurements span the waning stage of one eruptive cycle and the beginning of another and we observe increasing so2 burdens in the months prior to explosive eruptions of the volcano in july and august 2006 cumulative so2 loadings measured by omi yield a total of 1 16 tg so2 emitted by volcanoes on mainland ecuador s colombia between september 2004 and september 2006 as much as 95 of this so2 may originate from non eruptive degassing approximate apportionment of the total so2 loading indicates that 40 originated from tungurahua with 30 supplied by both reventador and galeras these measurements of volcanic so2 degassing in ecuador confirm omi s potential as an effective economical and risk free tool for daily monitoring of so2 emissions from hazardous volcanoes

multiparametric study of the february april 2013 paroxysmal phase of mt etna new south east crater european fp7 med suv mediterranean supersite volcanoes grant number 308665 european research council european fp7 fp 2007 2013 erc grant number 279802 sigma sistema integrato di sensori in ambiente cloud per la gestione multirischio avanzata

depletion rates of sulfur dioxide in tropospheric volcanic plumes the tropospheric sulfur cycle has been closely studied from the standpoint of anthropogenic emissions but less so with respect to volcanic sources we document here evidence for wide variation in lifetimes of volcanic so2 in the troposphere at one extreme our observations of the plume associated with the lavadome eruption of soufriere hills volcano montserrat suggest loss of gaseous so2 at rates exceeding 10 3 s 1 while this efficent so2 depletion reflects unusual environmental factors published measurements for mount etna s plume approach these rapid rates in such cases source strengths of so2 must significantly exceed apparent fluxes measured several kilometres downwind this implies that meteorological and geographic factors as well as volcanic degassing rates should be considered in the interpretation of fluxes of so2 measured beyond source vents with ramifications for volcano monitoring and eruption prediction furthermore since most calculations of global volcanic fluxes of sulfur and other species to the troposphere are based on extrapolation of so2 flux data they may underestimate true source strengths finally we consider that fast sulfur chemistry may also prevail in convecting eruption columns resulting in partial tropospheric scrubbing of sulfur from stratosphere bound plumes

the use of multispectral thermal infrared image data to estimate the sulfur dioxide flux from volcanoes a case study from mount etna sicily july 29 1986 the authors have found that image data acquired with nasa s airborne thermal infrared multispectral scanner tims can be used to make estimates of the so sub 2 content of volcanic plumes tims image data are most applicable to the study of partially transparent so sub 2 plumes such as those released during quiescent periods or nonexplosive eruptions the estimation procedure is based on the lowtran 7 radiative transfer code which the authors use to model the radiance perceived by tims as it views the ground through an so sub 2 plume the input to the procedure includes the altitudes of the aircraft and ground the altitude and thickness of the so sub 2 plume the emissivity of the ground and altitude profiles of the atmospheric pressure temperature and relative humidity they use the tims data to estimate both ground temperatures beneath a plume and so sub 2 concentrations within a plume applying this procedure to tims data acquired over mount etna sicily on july 29 1986 the authors estimate that the so sub 2 flux from the volcano was approximately 6700 t d sup minus 1 the use of tims to study so sub 2 plumes represents a bridge between highly localized methods such as correlation spectroscopy or directmore sampling and small scale mapping techniques involving satellite instruments such as the total ozone mapping spectrometer or microwave limb sounder the authors require further airborne experiments to refine their estimation procedure this refinement is a necessary preparation for the scheduled 1998 launch of the advanced spaceborne thermal emission and reflectance radiometer which will allow large scale multispectral thermal infrared image data to be collected over virtually any volcano on earth at least once every 16 days less

investigating crater lake warming using aster thermal imagery case studies at ruapehu poas kawah ijen and copahue volcanoes abstract a two channel or split window algorithm designed to correct for atmospheric conditions was applied to thermal images taken by the advanced spaceborne thermal emission and reflection radiometer aster of lake yugama on kusatsu shirane volcano in japan in order to measure the temperature of its crater lake these temperature calculations were validated using lake water temperatures that were collected on the ground overall the agreement between the temperatures calculated using the split window method and ground truth is quite good typically 1 5 c for cloud free images data from fieldwork undertaken in the summer of 2004 at kusatsu shirane allow a comparison of ground truth data with the radiant temperatures measured using aster imagery further images were analyzed of ruapehu poas kawah ijen and copahue volcanoes to acquire time series of lake temperatures a total of 64 images of these 4 volcanoes covering a wide range of geographical locations and climates were analyzed results of the split window algorithm applied to aster images are reliable for monitoring thermal changes in active volcanic lakes these temperature data when considered in conjunction with traditional volcano monitoring techniques lead to a better understanding of whether and how thermal changes in crater lakes aid in eruption forecasting

les debits de co2 et de so2 volcaniques dans l atmosphere la contribution des volcans a l atmosphere est reevaluee a 5 107 tonnes de so2 et 108 tonnes de co2 par an

deposition and degradation of a volatile rich layer in utopia planitia and implications for climate history on mars 1 we investigate the surface morphology of a study area in western utopia planitia mars which is characterized by a variety of landforms that resemble those of terrestrial periglacial landscapes polygonally fractured ground and thermokarst like depressions are found to be located in a young mantling deposit with a thickness of several tens of meters we observe a latitudinal dependence of the degradation of this mantling deposit larger depressions whose floors reveal the underlying basement rocks cover a higher fraction of the total terrain in the southern part of the study area than in the northern part indicating a more intense degradation of the mantle in the south all depressions have an asymmetric cross section in north south direction interpreted to be the result of the different solar radiation on differently oriented slopes on the basis of our morphological observations we develop a conceptual model for landscape evolution in western utopia planitia it involves subaerial deposition of a layered ice rich mantle and its subsequent degradation by polygon formation and sublimation a terrestrial analog to the polygonally fractured mantling deposit and its thermokarst like depressions is the siberian ice complex or yedoma which consists of subaerial ice rich deposits and is connected to nonglaciated landscapes with highly continental cold climatic environmental conditions our comparison suggests that no unusual or exotic processes need to be invoked to explain the current morphology of western utopia however the young age of the deposition and degradation implies climatic excursions in the very recent past on mars

the so2 camera a simple fast and cheap method for ground based imaging of so2 in volcanic plumes 1 so2 flux is widely monitored on active volcanoes as it gives a window into the hidden subsurface magma dynamics we present here a new approach to so2 flux monitoring using ultraviolet imaging of the volcanic plume through carefully chosen filters to produce images of so2 column amount the so2 camera heralds a breakthrough in both our ability to measure so2 flux at unprecedented frequencies 2 hz and at unprecedented accuracy thanks to the application of correlation techniques to determine wind speed directly from the images and the ability to measure the whole profile simultaneously in this paper we detail the commercially available pieces required to construct the so2 camera introduce a retrieval scheme to determine so2 amounts from the images and present results from a field campaign in november 2005 on sakurajima volcano japan

so2 flux measurements at mount etna sicily since 1987 over 220 measurements of the so2 flux at mount etna have been carried out using a correlation spectrometer cospec with different measuring techniques mainly with cospec mounted on a ground based vehicle this paper reports and analyzes the data obtained between october 1987 and december 1991 during this period three distinct time intervals characterized by particular so2 emission patterns were identified the first interval a showed a mean so2 flux of 5500 t d associated with relatively quiet summit crater eruptive activity the second interval b included two eruptive periods september october 1989 and january february 1990 associated with high fluxes reaching 10 000 25 000 t d the third interval c started in concert with a regional earthquake december 13 1990 and showed first a decrease and then an increase of so2 emissions before the onset of the major 1991 1993 flank eruption analysis of the data reveals a cyclic pattern to the so2 emissions over prolonged periods a nearly constant supply of so2 from the volcano s main feeder system especially evident in the long term a two to fivefold increase above mean flux values from 10 000 to 25 000 t d when occurring with paroxysmal eruptive activity and minimal flux values 1000 t d about 1 month prior to important eruptive events

idoas a new monitoring technique to study the 2d distribution of volcanic gas emissions imaging differential optical absorption spectroscopy idoas is an optical remote sensing method using scattered sunlight as light source it combines a pushbroom imaging spectrometer with the doas technique and thus allows imaging two dimensional trace gas distributions e g in volcanic plumes the highly sensitive and specific detection of many trace gases simultaneously specific molecules not just elements e g so2 bro no2 o3 hcho etc is possible and the temporal and spatial variation of these gases can be measured the idoas system presented here enables the taking of two dimensional images of trace gas distributions in a volcanic plume with a spatial resolution of 100 pixels horizontally 64 pixels vertically each with a field of view of 0 087 in horizontal and 0 208 in vertical directions therefore idoas provides useful information about the chemical composition and chemical variability in a volcanic plume and allows studying plume dispersal and chemical transformations the technique was applied to map the so2 distribution in the plume of mt etna volcano for the first time in october 2003

so2 loss rates in the plume emitted by soufriere hills volcano montserrat to improve interpretation of volcanic so2 flux data it is necessary to quantify and understand reactions involving so2 in volcanic plumes so2 is lost in volcanic plumes through a number of mechanisms here we report so2 measurements made with miniature ultraviolet spectrometers at soufriere hills volcano montserrat a low altitude volcano 1000 m above sea level whose plume entrains humid marine air in the planetary boundary layer traverses very near 2 km downwind from soufriere hills volcano significantly underestimate at source so2 emission rates on the order of 70 146 when not accounting for the decay rate similar so2 loss is likely to occur in plumes from other tropical low altitude volcanoes under conditions of high relative humidity 20 of active volcanoes worldwide these results suggest that the global volcanic so2 emission rate may be underestimated as the estimates are based on measurements taken downwind of volcanoes by which time significant loss of so2 may have taken place the loss rates calculated here could be used in conjunction with downwind so2 fluxes to estimate at source so2 emission rates from volcanoes with similar environmental conditions to those at soufriere hills volcano

sulfur dioxide flux estimation from volcanoes using advanced spaceborne thermal emission and reflection radiometer a case study of miyakejima volcano japan abstract a method is described for estimating the two dimensional spatial distribution of volcanic so2 using thermal infrared image data acquired by the advanced spaceborne thermal emission and reflection radiometer aster the author proposes a new method to estimate wind velocity and plume height using an along track stereoscopic pair image volcanic so2 flux can be estimated from the spatial distribution of so2 and wind velocity since aster has both the thermal infrared radiometer tir and stereoscopic viewing function in the along track direction the volcanic so2 flux can be estimated from the aster data alone these methods are applied to the miyakejima volcano japan the so2 flux derived from aster is around 5 104 ton day 580 kg s 1 which is slightly larger than the value derived from cospec the plume height estimation error may cause this disagreement because the so2 estimation procedure is very sensitive to the plume height

aster watches the world s volcanoes a new paradigm for volcanological observations from orbit onboard nasa terra spacecraft is one of the most sophisticated earth observing instruments ever flown the advanced spaceborne thermal emission and reflection radiometer aster created as part of a joint project between the japanese ministry of economy trade and industry and nasa this instrument consists of three independent bore sighted telescopes with 14 channels in the visible near infrared and thermal infrared regions capable of being pointed up to 22 5 off nadir in addition there is an additional backward looking visible channel telescope for stereo photogrammetric observations the spatial resolutions are 15 m pixel in the visible 30 m pixel in the near ir and 90 m pixel at thermal wavelengths and the swath width is 60 km aster instrument offers unprecedented opportunities for observing volcanoes and their activity from low earth orbit it is the purpose of this short paper to introduce aster to the volcanological community highlight its capabilities advantages and limitations and to show some examples of aster data and related analyses we will also explain how users can readily access aster data

thermal infrared remote sensing of volcanic emissions using the moderate resolution imaging spectroradiometer the volcanological community has a powerful new tool in the spaceborne moderate resolution imaging spectroradiometer modis which from its synoptic perspective provides satellite imagery of every volcano on earth every 2 days modis has the spectral characteristics to be able to utilise previously developed retrievals that quantify volcanic ash ice sulfates and sulfur dioxide using their thermal infrared 8 12 am transmission signature in this paper we present a detailed description of the methodologies based within the thermal infrared region that are being applied to modis data modis data for two eruptions hekla iceland and cleveland alaska are presented to show results from the ice ash and so2 retrieval schemes we look at current problems with the retrievals used to quantify volcanic emissions detail recent developments within the field that can be applied to modis data and suggest areas where improvements need to be made in the future published by elsevier b v

computed tomography reconstruction of so2 concentration distribution in the volcanic plume of miyakejima japan by airborne traverse technique using three uv spectrometers 1 we present here a new method for measuring the so2 concentration distribution in a volcanic plume cross section by using the airborne traverse technique with three uv spectrometers and calculating a computed tomography ct reconstruction our observation requires only one traverse and is as easy as conventional measurements of so2 flux the plume is traverse scanned using three uv spectrometers aligned at three different zenith angles and a ct technique initially designed for air pollutant monitoring was improved by using akaike s bayesian information criterion abic we applied this method to a volcanic plume at 10 km downwind from the caldera of miyakejima volcano in aug 2004 the results of the application show that the profile of the plumes significantly changed in only a matter of a few minutes due to the flexibility and ease of the observation procedure this method is widely applicable to various fields and shows promise in volcanic gas monitoring

simultaneous retrieval of volcanic ash and so2 using msg seviri measurements 1 volcanic ash and sulphur dioxide masses from the november 2005 eruption of karthala volcano comoros islands are simultaneously retrieved using rapid scan multispectral infrared measurements from the spin enhanced visible and infrared imager on board the meteosat second generation geosynchronous satellite retrievals are made every 15 min which show that the ash and so2 separate in the vertically sheared atmosphere producing a fast moving upper level 12 km so2 cloud a slower moving middle level 8 km ash cloud and a boundary layer 3 km so2 plume the total mass of fine ash is 0 1 0 05 tg sio2 the upper level so2 mass is 0 19 0 01 tg s while the boundary layer so2 mass is 0 009 0 01 tg s these are the first simultaneous satellite measurements of ash and so2 from an erupting volcano and confirm previous ideas about vertical separation we suggest care must be exercised when using so2 as a tracer for volcanic ash in aviation hazard warning systems

comparison of cospec and two miniature ultraviolet spectrometer systems for so2 measurements using scattered sunlight the correlation spectrometer cospec the principal tool for remote measurements of volcanic so2 is rapidly being replaced by low cost miniature ultraviolet uv spectrometers we compared two of these new systems with a cospec by measuring so2 column amounts at k lauea volcano hawaii the two systems one calibrated using in situ so2 cells and the other using a calibrated laboratory reference spectrum employ similar spectrometer hardware but different foreoptics and spectral retrieval algorithms accuracy signal to noise retrieval parameters and precision were investigated for the two configurations of new miniature spectrometer measurements included traverses beneath the plumes from the summit and east rift zone of k lauea and testing with calibration cells of known so2 concentration the results obtained from the different methods were consistent with each other with 8 difference in estimated so2 column amounts up to 800 ppm m a further comparison between the cospec and one of the miniature spectrometer configurations the flyspec spans an eight month period and showed agreement of measured emission rates to within 10 for so2 column amounts up to 1 600 ppm m the topic of measuring high so2 burdens accurately is addressed for the k lauea measurements in comparing the foreoptics retrieval methods and resultant implications for data quality we aim to consolidate the various experiences to date and improve the application and development of miniature spectrometer systems

reconstruction of so2 flux emission chronology from space based measurements abstract infrared satellite images measured with the modis instrument of the volcanic plume produced during the 2006 eruption of mt etna were analysed to produce maps of so 2 amount we used these maps to reconstruct time series of so 2 fluxes by integrating profiles of so 2 orthogonal to the plume advection direction and multiplying with wind speeds from a meteorological model these data were then compared with a reconstructed time series of so 2 fluxes measured with the flame ground based network of ultraviolet doas systems surrounding the volcano we found weak agreement on 3rd december when little ash was emitted but this agreement improved when a 0 3 m s 1 wind speed correction factor was used flame and modis results were in good agreement on the 6th december and improved when a 0 3 m s 1 offset was applied the corrected data revealed that the only period of time when flame and modis did not track together was coincident with the presence of ash which interferes with the ir imagery and retrieval of so 2 we highlight that combining two independent time series of so 2 flux allows a precise determination of wind speed if there is sufficient time dependent structure in the so 2 signal the observed increase in so 2 flux prior to the ash emission is interpreted as a quiescent release of an accumulated gas phase that drive eruptive activity as previously suggested for the southeast crater system of etna in this case the so 2 flux signal therefore acted as a precursor to the eruptive ash events this work demonstrates that quantitative reconstruction of so 2 flux time series is feasible using modis data opening a new frontier in the use of satellite data to interpret volcanic processes in particular in poorly monitored remote locations

measuring volcanic degassing of so2 in the lower troposphere with aster band ratios we present a new method for measuring so2 with the data from the aster advanced spaceborne thermal emission and reflectance radiometer orbital sensor the method consists of adjusting the so2 column amount until the ratios of radiance simulated on several aster bands match the observations we present a sensitivity analysis for this method and two case studies the sensitivity analysis shows that the selected band ratios depend much less on atmospheric humidity sulfate aerosols surface altitude and emissivity than the raw radiances measurements with 25 relative precision are achieved but only when the thermal contrast between the plume and the underlying surface is higher than 10 k for the case studies we focused on miyakejima and etna two volcanoes where so2 is measured regularly by cospec or scanning doas the so2 fluxes computed from a series of ten images of miyakejima over the period 2000 2002 is in agreement with the long term trend of measurement for this volcano on etna we compared so2 column amounts measured by aster with those acquired simultaneously by ground based automated scanning doas the column amounts compare quite well providing a more rigorous validation of the method the so2 maps retrieved with aster can provide quantitative insights into the 2d structure of non eruptive volcanic plumes their dispersion and their progressive depletion in so2

development of an ultra violet digital camera for volcanic so2 imaging abstract in an effort to improve monitoring of passive volcano degassing we have constructed and tested a digital camera for quantifying the sulfur dioxide so 2 content of volcanic plumes the camera utilizes a bandpass filter to collect photons in the ultra violet uv region where so 2 selectively absorbs uv light so 2 is quantified by imaging calibration cells of known so 2 concentrations images of volcanic so 2 plumes were collected at four active volcanoes with persistent passive degassing villarrica located in chile and santiaguito fuego and pacaya located in guatemala images were collected from distances ranging between 4 and 28 km away with acceptable detection up to approximately 16 km camera set up time in the field ranges from 5 10 min and temporal resolution of up to 6 images per minute is possible which combined with the camera s field of view makes a continuous so 2 dataset attainable variable in plume concentrations can be observed and accurate plume speeds or rise rates can readily be determined by tracing individual portions of the plume within sequential images initial fluxes computed from camera images require a correction for the effects of environmental light scattered into the field of view at fuego volcano simultaneous measurements of corrected so 2 fluxes with the camera and a correlation spectrometer cospec agreed within 25 experiments at the other sites were equally encouraging and demonstrated the camera s ability to detect so 2 under variable background meteorological and environmental conditions this early work has shown great success in imaging so 2 plumes and offers promise for volcano monitoring due to its rapid deployment and data processing capabilities relatively low cost and improved interpretation afforded by synoptic coverage from a range of distances

confirming geomorphological interpretations based on portable osl reader data portable optically stimulated luminescence osl readers are increasingly being used in geomorphological and archaeological investigations but information regarding data reproducibility and the reliability of interpretations based on portable osl reader data has not yet been presented to the wider geomorphological community this letter addresses these two issues by returning to grabben gullen creek in the southeastern australian tablelands where we remeasure a sediment profile that was first measured by other researchers 3 years earlier we also compare portable osl reader data measured on sediment interpreted to have been deposited in swampy meadow wetlands and flood alluvium settings with data measured on known swampy meadow and flood deposits our data show that portable osl reader data are reproducible moreover we confirm the earlier interpretation that stratigraphies commonly exposed in southeastern australian tablelands valley bottoms reflect pre european swampy meadow wetlands and flood alluvium copyright 2015 john wiley sons ltd

three years of so2 flux measurements of mt etna using an automated uv scanner array comparison with conventional traverses and uncertainties in flux retrieval 1 sviluppo di sistemi di monitoraggio dipartimento di protezione civile della regione sicilia 2 ingv istituto nazionale di geofisica e vulcanologia sezione di catania italy 3 novac network for observation of volcanic and atmospheric change eu funded sixth framework programme project 18354 4 uk nerc national centre for earth observation via the dynamic earth and geo hazards