thermal monitoring of north pacific volcanoes from space long term thermal modeling of volcanoes using satellite imagery provides an effective tool for monitoring remote yet dangerous volcanoes in the north pacific this region includes volcanoes in alaska the aleutian islands and the kamchatkan peninsula thermal infrared data collected multiple times per day from weather satellites show distinct signatures for three different types of volcanic activity at different volcanic centers near real time automated techniques are being developed to monitor relative changes in radiant temperature at volcanoes in this region radiant temperature values as a function of time are extracted and compared to background values for a series of active volcanoes by establishing a long term thermal record for these volcanoes significant deviations indicative of an impending eruption can be detected this tool is used to search for precursors to explosive eruptions in order to increase warning times and hazard mitigation for these potentially catastrophic events a six year archive of satellite imagery has been compiled for this active region and is available for study

shallow magma transport for the 2002 3 mt etna eruption inferred from thermal infrared surveys abstract the 26 october 2002 28 january 2003 eruption of mt etna volcano was characterised by lava effusion and by an uncommon explosivity along a 1 km long eruptive fissure on the southern upper flank of the volcano the intense activity promoted rapid growth of cinder cones and several effusive vents analysis of thermal images recorded throughout the eruption allowed investigation of the distribution of vents along the eruptive fissure and of the nature of explosive activity the spatial and temporal distribution of active vents revealed phases of dike intrusion expansion geometric stabilization and drainage these phases were characterised by different styles of explosive activity with a gradual transition from fire fountaining through transitional phases to mild strombolian activity and ending with non explosive lava effusion here we interpret the mechanisms of the dike emplacement and the eruptive dynamics according to changes in the eruptive style vent morphology and apparent temperature variations at vents detected through thermal imaging this is the first time that dike emplacement and eruptive activity have been tracked using a handheld thermal camera and we believe that its use was crucial to gain a detailed understanding of the eruptive event

improved remote sensing estimates of lava flow cooling a case study of the 1991 1993 mount etna eruption infrared radiance data acquired by the landsat thematic mapper tm provide information regarding the thermal state of active lavas which can be used to estimate flow surface temperatures and thus lava cooling saturation of one or both of tm s short wave infrared swir wavebands has meant however that previous studies of lava flow cooling have approximated what is almost certainly an n thermal component flow surface temperature distribution where n 1 with a single pixel integrated temperature pit we show that the high sensitivity of tm s swir wavebands to the small amount of high temperature e g 1000 c material exposed in hot fractures within the flows cooler e g 200 c surface crust results in the calculation of pits that are higher than the temperature of this crust which is usually the dominant radiative component this causes heat loss from such pixels to be overestimated we present adaptations that allow more realistic heat loss estimates to be produced using tm data by assuming that a second high temperature component contributes to the radiance measured from saturated pixels and by defining an appropriate range for the temperature of the lava crust by analyzing a suite of five tm images acquired during the 1991 1993 eruption of mount etna we present more realistic estimates of how this flow cooled as well as results that show how the flow regime of the lava evolved over time the methods we present will continue to be of use as although the next generation of high spatial resolution sensors such as the landsat 7 enhanced thematic mapper plus etm and the terra advanced space borne thermal emission and reflection radiometer aster will be less susceptible to saturation than tm the problem will still persist

lava lake surface characterization by thermal imaging erta ale volcano ethiopia the project sviluppo di sistemi di monitoraggio dipartimento di protezione civile di regione sicilia ingv catania section italy the leverhulme trust the bbc and the ethiopian air force

ground based thermal imaging of lava lakes at erebus volcano antarctica abstract mount erebus a large intraplate stratovolcano dominating ross island antarctica hosts the world s only active phonolite lava lakes the main manifestation of activity at erebus volcano in december 2004 was as the presence of two convecting lava lakes within an inner crater the long lived ray lake 1400 m2 in area was the site of up to 10 small strombolian eruptions per day a new but short lived 1000 1200 m2 lake formed at werner vent in december 2004 sourced by lava flowing from a crater formed in 1993 by a phreatic eruption we measured the radiative heat flux from the two lakes in december 2004 using a compact infrared ir imaging camera daily thermal ir surveys from the main crater rim provide images of the lava lake surface temperatures and identify sites of upwelling and downwelling the radiative heat outputs calculated for the ray and werner lakes are 30 35 mw and 20 mw respectively we estimate that the magma flux needed to sustain the combined heat loss is 250 710 kg s 1 that the minimum volume of the magma reservoir is 2 km3 and that the radius of the conduit feeding the ray lake is 2 m

characterization of volcanic thermal anomalies by means of sub pixel temperature distribution analysis the simultaneous solution of the planck equation involving the widely used dual band technique using two shortwave infrared swir bands allows for an estimate of the fractional area of the hottest part of an active lava flow f h and the background temperature of the cooler crust t c the use of a high spectral and spatial resolution imaging spectrometer with a wide dynamic range of 15 bits dais 7915 in the wavelength range from 0 501 to 12 67 m resulted in the identification of crustal temperature and fractional areas for an intra crater hot spot at mount etna italy this study indicates the existence of a relationship between these t c and f h extracted from dais and landsat tm data when the dual band equation system is performed on a lava flow a logarithmic distribution is obtained from a plot of the fractional area of the hottest temperature vs the temperature of the cooler crust an entirely different distribution is obtained over active degassing vents where increases in t c occur without any increase in f h this result indicates that we can use scatter plots of t c vs fh to discriminate between different types of volcanic activity in this case between degassing vents and lava flows using satellite thermal data

organic carbon isotope systematics of coastal marshes abstract measurements of nitrogen organic carbon and 13c are presented forspartina dominated marsh sediments from a mineral marsh in sw netherlands and from a peaty marsh in massachusetts u s a 13c of organic carbon in the peaty marsh sediments is similar to that ofspartinamaterial whereas that in mineral marshes is depleted by 9 12 it is argued that this depletion in 13c of organic matter in marsh sediments is due to trapping of allochthonous organic matter which is depleted in13c the isotopic composition and concentration of organic carbon are used in a simple mass balance to constrain the amount of plant material accumulating in marsh sediments i e in terms of the so called net ecosystem production net ecosystem production 2 100 g c m 2year 1 is a small fraction 1 5 of plant production 2000 g c m 2year 1 this small amount of plant material being preserved is nevertheless sufficient to support marsh accretion rates similar to the rate of sea level rise

combined use of seviri and modis for detecting measuring and monitoring active lava flows at erupting volcanoes multispectral data acquired by spinning enhanced visible and infrared imager seviri onboard the geostationary platform meteosat second generation msg2 located at 0deg longitude were analyzed to assess the payload suitability for quantitative volcano monitoring in times of good infrared transparency of the troposphere seviri data proved particularly suited to detect the onset of effusive eruptions and to monitor the related lava flows with 15 min refresh rates after development of a code allowing for fast automated processing of the 96 data streams downlinked daily by msg2 thorough monitoring tests were carried out on the 2007 eruptions of stromboli aeolian islands italy and piton de la fournaise reunion island france the results in radiant flux and effusion rate provided by use of thermal mid and short infrared bands of seviri were validated by exploiting simultaneous modis overpasses by terra and aqua up to four times daily

modvolc near real time thermal monitoring of global volcanism modvolc is a non interactive algorithm developed at the hawaii institute of geophysics and planetology higp that uses low spatial resolution 1 km pixel size infrared satellite data acquired by the moderate resolution imaging spectroradiometer modis to map the global distribution of volcanic thermal anomalies in near real time modvolc scans the level 1b modis data stream on a pixel by pixel basis for evidence of pixel and sub pixel sized high temperature radiators once a hot spot has been identified its details location emitted spectral radiance time satellite observation geometry are written to ascii text files and transferred via ftp to higp from where the results are disseminated via the internet http modis higp hawaii edu in this paper we review the underlying principles upon which the algorithm is based before presenting some of the results and data that have been obtained since its inception we show how modvolc reliably detects thermal anomalies at a large number of persistently and sporadically active volcanoes that encompass the full range of common eruptive styles including erebus antarctica colima mexico karymsky kamchatka popocatepetl mexico etna italy and nyiragongo democratic republic of congo amongst others we also present a few cautionary notes regarding the limitations of the algorithm and interpretation of the data it provides

a lithospheric velocity anomaly beneath the shagan river test site part 2 imaging and inversion with amplitude transmission tomography a linear inversion procedure is introduced that images weak velocity anomalies using amplitudes of transmitted seismic waves using projection operators from geometrical ray theory an image of an anomaly is constructed from amplitudes recorded at arrays of receivers using arrays of sources the image is related to the velocity anomaly by a second order partial differential equation that is inverted using 2 d discrete fourier transforms as an example of the inversion procedure magnitude residuals for european stations recording shagan river explosions are used to image the deep lithospheric anomaly beneath the shagan river test site described in part 1 this formal inversion analysis confirms the existence of a small scale lateral heterogeneity located 50 km west northwest of the test site at a probable depth between 80 and 100 km and indicates that it is consistent with a deterministic 1 5 peak to peak or 0 5 rms velocity anomaly with a scale length of about 3 km 3 d dynamic raytracing is then used to verify that the inferred laterally varying structure produces amplitude fluctuations consistent with observations

conclusion recommendations and findings of the red seed working group red seed stands for risk evaluation detection and simulation during effusive eruption disasters and combines stakeholders from the remote sensing modelling and response communities with experience in tracking volcanic effusive events the group first met during a three day long workshop held in clermont ferrand france between 28 and 30 may 2013 during each day presentations were given reviewing the state of the art in terms of a volcano hot spot detection and parameterization b operational satellite based hot spot detection systems c lava flow modelling and d response protocols during effusive crises at the end of each presentation set the four groups retreated to discuss and report on requirements for a truly integrated and operational response that satisfactorily combines remote sensors modellers and responders during an effusive crisis the results of collating the final reports and follow up discussions that have been on going since the workshop are given here we can reduce our discussions to four main findings 1 hot spot detection tools are operational and capable of providing effusive eruption onset notice within 15 min 2 spectral radiance metrics can also be provided with high degrees of confidence however if we are to achieve a truly global system more local receiving stations need to be installed with hot spot detection and data processing modules running on site and in real time 3 models are operational but need real time input of reliable time averaged discharge rate data and regular updates of digital elevation models if they are to be effective the latter can be provided by the radar photogrammetry community 4 information needs to be provided in an agreed and standard format following an ensemble approach and using models that have been validated and recognized as trustworthy by the responding authorities all of this requires a sophisticated and centralized data collection distribution and reporting hub that is based on a philosophy of joint ownership and mutual trust while the next chapter carries out an exercise to explore the viability of the last point the detailed recommendations behind these findings are detailed here

first recorded eruption of mount belinda volcano montagu island south sandwich islands the modvolc satellite monitoring system has revealed the first recorded eruption of mount belinda volcano on montagu island in the remote south sandwich islands here we present some initial qualitative observations gleaned from a collection of satellite imagery covering the eruption including modis landsat 7 etm aster and radarsat 1 data modvolc thermal alerts indicate that the eruption started sometime between 12 september and 20 october 2001 with low intensity subaerial explosive activity from the island s summit peak mount belinda by january 2002 a small lava flow had been emplaced near the summit and activity subsequently increased to some of the highest observed levels in august 2002 observations from passing ships in february and march 2003 provided the first visual confirmation of the eruption aster images obtained in august 2003 show that the eruption at mount belinda entered a new phase around this time with fresh lava effusion into the surrounding icefield modis radiance trends also suggest that the overall activity level increased significantly after july 2003 thermal anomalies continued to be observed in modis imagery in early 2004 indicating a prolonged low intensity eruption and the likely establishment of a persistent summit lava lake similar to that observed on neighboring saunders island in 2001 our new observations also indicate that lava lake activity continues on saunders island

multi instrument remote and in situ observations of the erebus volcano antarctica lava lake in 2005 a comparison with the pele lava lake on the jovian moon io abstract the stable persistent active lava lake at erebus volcano ross island antarctica provides an excellent thermal target for analysis of spacecraft observations and for testing new technology in the austral summer of 2005 visible and infrared observations of the erebus lava lake were obtained with sensors on three space vehicles terra aster modis aqua modis and eo 1 hyperion ali contemporaneous ground based observations were obtained with hand held infrared cameras this allowed a quantitative comparison of the thermal data obtained from different instruments and of the analytical techniques used to analyze the data both with and without the constraints imposed by ground truth from the thermal camera data in december 2005 the main erebus lava lake ray lake had an area of 820 m2 surface colour temperatures ranged from 575 k to 1090 k with a broad peak in the distribution from 730 k to 850 k total heat loss was estimated at 23 5 mw the flux density was 29 kw m 2 mass flux was estimated at 64 to 93 kg s 1 the best correlation between thermal emission and emitting area was obtained with aster which has the best combination of spatial resolution and wavelength coverage especially in the thermal infrared the high surface temperature of the lava lake means that hyperion data are for the most part saturated uncertainties introduced by the need to remove incident sunlight cause the thermal emission from the hyperion data to be a factor of about two greater than that measured by hand held thermal camera modis also over estimated thermal output from the lava lake by the same factor of two because it was detecting reflected sunlight from the rest of the pixel area the measurement of the detailed temperature distribution on the surface of an active terrestrial lava lake will allow testing of thermal emission models used to interpret remote sensing data of volcanism on io where no such ground truth exists although the erebus lava lake is four orders of magnitude smaller than the lava lake at pele on io the shape of the integrated thermal emission spectra are similar thermal emission from this style of effusive volcanism appears to be invariant excess thermal emission in most pele spectra compared to erebus at short wavelengths

coupled use of cospec and satellite measurements to define the volumetric balance during effusive eruptions at mt etna italy using etna as a case study location we examine the balance between the volume of magma supplied to the shallow volcanic system using ground based so2 data and the volume erupted using satellite thermal data we do this for three eruptions of mt etna italy during 2002 to 2006 we find that during the three eruptions 2 3 107 m3 or 24 of the degassed volume remained unerupted however variations in the degree of partitioning between supplied vsupply and erupted verupt magma occur within individual eruptions over the time scales of days consequently we define and quantify three types of partitioning in the first case vsupply verupt i e less lava is erupted than is supplied in such a case magma can erupt in an explosive manner as occurred during phase ii of the 2002 2003 eruption or remain within or below the edifice in the third case vsupply verupt i e all supplied magma is erupted during 2002 2006 over a total of 280 days of eruptive activity this balancing case applied to 50 of the time

contrasting triggering mechanisms of the 2001 and 2002 2003 eruptions of mount etna italy abstract mount etna produced two significant eruptions in 2001 and 2002 2003 which we have analysed using geological seismic and deformation data these eruptions showed some similarities such as the activating of two magmatic plumbing systems central lateral and eccentric but they differed in their triggering mechanisms while the 2001 eruption was largely the result of the emplacement of a n s eccentric dike independent from the central conduits consistent with e w regional extension the 2002 2003 eruption occurred in response to a major flank slip on the eastern and southeastern sides of the volcano this is demonstrated by the spatial and temporal distribution of seismicity and deformation preceding and accompanying the two eruptions during the months prior to the 2001 eruption most epicenters were concentrated on the southern flank at depths of 5 15 km below sea level during the 4 days before the eruption earthquake hypocenters migrated to shallower levels from 5 km bsl upward indicating the emplacement of the eccentric dike this is confirmed by the patterns of ground fracturing observed in the field and deformation documented by electronic distance measurements edm in contrast the months before the 2002 2003 eruption were characterised by shallower seismicity mainly concentrated along the active faults bordering the slipping flank sector flank slip accelerated in september 2002 and a second more vigorous acceleration of flank slip occurred on 26 27 october 2002 accompanying the opening of eruptive vents the very short 2 h seismic crisis preceding the onset of eruptive activity stands in neat contrast with the 4 days of intense seismicity before the 2001 eruption subsequently flank slip deformation extended all over the eastern and southeastern flanks of the volcano causing serious damage in this sector the events of 2001 2003 can be seen as a continuous chain of intimately interacting processes including regional tectonics magma accumulation and eruption and flank instability in this scenario the 2001 eruption led to increased flank instability that subsequently accelerated and culminated with the massive flank slip which in turn facilitated the 2002 2003 eruption this sequence of events points to a long term feedback mechanism between magmatism and flank instability at etna

a review of algorithms for detecting volcanic hot spots in satellite infrared data since the 1980s application of thermal infrared satellite data for volcano monitoring has rapidly evolved to become a proven operational tool due to the large quantities of data provided by sensors in polar and geostationary orbits as well as the sheer number of active volcanoes on earth processing and managing such data sets requires an enormous amount of workforce a number of algorithms have been developed to facilitate detection location and tracking of hot spots of active volcanoes a collation and review of hot spot detection algorithms developed and applied by the volcanological community reveals three main types which have been applied to date contextual fixed threshold and temporal the founding algorithms for these three classes are vast modvolc and rst respectively through comparison with manually based detections the performance of each algorithm was tested for sustained lava flows etna and stromboli strombolian activity stromboli lava dome growth and collapse augustine and fumarole fields vulcano it is shown that as the number of correctly identified anomalies increases so too does the number of false positives although each of the algorithms operates well within the limits and criteria of their design requirements and application under current data restraints no algorithm can be expected to perform perfectly

some observations regarding the thermal flux from earth s erupting volcanoes for the period of 2000 to 2014 we present satellite measurements of the thermal flux observed from 95 active volcanoes based on observations made daily over the past 15 years by nasa s terra and aqua moderate resolution imaging spectroradiometer sensors excursions from an apparent baseline level of thermal emission are attributable to episodic lava flow forming eruptions highest average intensity was associated with the july 2001 eruption of etna italy which radiated an average of 2 5 109 w over 23 days however recent fissure eruptions in the afar rift have attained higher average intensities of 2 4 4 4 109 w albeit for days not weeks the largest magnitude eruption was the ongoing eruption of bardarbunga iceland which radiated 2 6 1016 j k lauea hawai i has radiated the most energy since 2000 although the lava lake at nyiragongo democratic republic of congo comes a close second time series analysis reveals evidence for periodicity in radiant flux at some volcanoes but not at others

earthquake induced thermal anomalies at active volcanoes answering the question whether a regional earthquake can trigger or enhance volcanic activity requires a systematic measure of volcanic activity one such measure is heat fl ux the availability since a d 2000 of a satellite derived heat fl ux inventory for global volcanism allows us to explore how earthquakes and volcanic activity may be linked examination of 7 yr of global volcanic heat fl ux data reveals 37 volcanic responses to regional earthquakes each response is expressed by an increase in heat fl ux within 1 21 days of the triggering earthquake whether a volcano responds depends on earthquake magnitude distance to the epicenter and orientation of the earthquake focal mechanism in respect to the volcano the focal mechanism has to align with the responding system of the 7 global major increases of seismic energy during 2000 2006 4 were followed by a global volcanic heat fl ux increase the largest response involved a 300 increase and followed the largest earthquake in the period the 2004 sumatraandaman indonesia earthquake moment magnitude m w 9 3

exploring the limits of identifying sub pixel thermal features using aster tir data abstract understanding the characteristics of volcanic thermal emissions and how they change with time is important for forecasting and monitoring volcanic activity and potential hazards satellite instruments view volcanic thermal features across the globe at various temporal and spatial resolutions thermal features that may be a precursor to a major eruption or indicative of important changes in an on going eruption can be subtle making them challenging to reliably identify with satellite instruments the goal of this study was to explore the limits of the types and magnitudes of thermal anomalies that could be detected using satellite thermal infrared tir data specifically the characterization of sub pixel thermal features with a wide range of temperatures is considered using aster multispectral tir data first theoretical calculations were made to define a thermal mixing detection threshold for aster which quantifies the limits of aster s ability to resolve sub pixel thermal mixing over a range of hot target temperatures and pixel areas then aster tir data were used to model sub pixel thermal features at the yellowstone national park geothermal area hot spring pools with temperatures from 40 to 90 c and at mount erebus volcano antarctica an active lava lake with temperatures from 200 to 800 c finally various sources of uncertainty in sub pixel thermal calculations were quantified for these empirical measurements including pixel resampling atmospheric correction and background temperature and emissivity assumptions

observations of mt etna volcanic ash plumes in 2006 an integrated approach from ground based and polar satellite noaa avhrr monitoring system abstract mt etna in sicily italy is one of the world s most frequent emitters of volcanic plumes during the last ten years etna has produced copious tephra emission and fallout that have damaged the inhabited and cultivated areas on its slopes and created serious hazards to air traffic recurrent closures of the catania international airport have often been necessary causing great losses to the local economy recently frequent episodes of ash emission lasting from a few hours to days occurred from july to december 2006 necessitating a look at additional monitoring techniques such as remote sensing the combination of a ground monitoring system with polar satellite data represents a novel approach to monitor etna s eruptive activity and makes etna one of the few volcanoes for which this surveillance combination is routinely available in this work ash emission information derived from an integrated approach based on comparing ground and noaa avhrr polar satellite observations is presented this approach permits us to define the utility of real time satellite monitoring systems for both sporadic and continuous ash emissions using field data visible observations collection of tephra samples and accounts by local inhabitants the duration and intensity of most of the tephra fallout events were evaluated in detail and in some cases the order of magnitude of the erupted volume was estimated the ground data vs satellite data comparison allowed us to define five different categories of etna volcanic plumes according to their dimensions and plume height taking into account wind intensity using frequent and good quality satellite data in real time this classification scheme could prove helpful for investigations into a possible correlation between eruptive intensity and the presence and concentration of ash in the volcanic plume the development and improvement of this approach may constitute a powerful warning system for civil protection thus preventing unnecessary airport closures

volcano monitoring using short wavelength infrared data from satellites data from remote sensing satellites operating in the short wavelength infrared can be used to measure temperatures of about 150 c and above the gain settings of the landsat thematic mapper tm sensors are such that to record pixel integrated temperatures from 150 c to over 1000 c requires the use of several spectral bands if the radiant source occupies less than a whole pixel as is the case for fumaroles or a crusted lava surface with incandescent cracks then the pixel integrated temperature is less than the actual surface temperature of the hot areas and appears to be different at each wavelength by determining pixel integrated temperature in two spectral bands we can estimate both the temperature and size of hot areas which occupy less than a complete pixel in some cases our observations provide the only available data on the state of activity of a particular volcano in others they support and refine field observations our landsat tm data reveal otherwise unobserved precursor and subsequent activity related to the september 1986 eruption of lascar volcano chile and supplement other data on the march 1986 eruption of augustine volcano alaska they also indicate the continued presence of lava lakes at erta ale ethiopia in the absence of any ground based observations and document minor eruptive activity at mount erebus antarctica landsat multispectral scanner data have been used to measure the variation in temperature along a lava flow on sierra negra galapagos islands which occurred in 1979

time series analysis of infrared satellite data for detecting thermal anomalies a hybrid approach we developed and tested an automated algorithm that analyzes thermal infrared satellite time series data to detect and quantify the excess energy radiated from thermal anomalies such as active volcanoes our algorithm enhances the previously developed modvolc approach a simple point operation by adding a more complex time series component based on the methods of the robust satellite techniques rst algorithm using test sites at anatahan and k lauea volcanoes the hybrid time series approach detected 15 more thermal anomalies than modvolc with very few if any known false detections we also tested gas flares in the cantarell oil field in the gulf of mexico as an end member scenario representing very persistent thermal anomalies at cantarell the hybrid algorithm showed only a slight improvement but it did identify flares that were undetected by modvolc we estimate that at least 80 modis images for each calendar month are required to create good reference images necessary for the time series analysis of the hybrid algorithm the improved performance of the new algorithm over modvolc will result in the detection of low temperature thermal anomalies that will be useful in improving our ability to document earth s volcanic eruptions as well as detecting low temperature thermal precursors to larger eruptions

lava effusion rate definition and measurement a review measurement of effusion rate is a primary objective for studies that model lava flow and magma system dynamics as well as for monitoring efforts during on going eruptions however its exact definition remains a source of confusion and problems occur when comparing volume flux values that are averaged over different time periods or spatial scales or measured using different approaches thus our aims are to 1 define effusion rate terminology and 2 assess the various measurement methods and their results we first distinguish between instantaneous effusion rate and time averaged discharge rate eruption rate is next defined as the total volume of lava emplaced since the beginning of the eruption divided by the time since the eruption began the ultimate extension of this is mean output rate this being the final volume of erupted lava divided by total eruption duration whether these values are total values i e the flux feeding all flow units across the entire flow field or local i e the flux feeding a single active unit within a flow field across which many units are active also needs to be specified no approach is without its problems and all can have large error up to 50 however good agreement between diverse approaches shows that reliable estimates can be made if each approach is applied carefully and takes into account the caveats we detail here there are three important factors to consider and state when measuring giving or using an effusion rate first the time period over which the value was averaged second whether the measurement applies to the entire active flow field or a single lava flow within that field and third the measurement technique and its accompanying assumptions

lava flow thermal analysis using three infrared bands of remote sensing imagery a study case from mount etna 2001 eruption abstract infrared remotely sensed data can be used to estimate heat flux and thermal features of active volcanoes the model proposed by crisp and baloga crisp j baloga s 1990 a model for lava flows with two thermal components journal of geophysical research 95 1255 1270 for active lava flows considers the thermal flux a function of the fractional area of two thermally distinct radiant surfaces the larger surface area corresponds to the cooler crust of the flow the smaller one to fractures in the crust in this model the crust temperature t c the temperature of the cracks t h and the fractional area of the hottest component f h represent the three unknowns to work out the simultaneous solution of the planck equation dual band technique for two distinct shortwave infrared swir bands allows to estimate any two of the parameters t c t h f h if the third is assumed dozier j 1981 a method for satellite identification of surface temperature fields of subpixel resolution remote sensing environment 11 221 229 the airborne sensor mivis was flown on mount etna during the july august 2001 eruption this hyperspectral imaging spectrometer offers 72 bands in the swir range and 10 bands in thermal infrared tir region of the spectrum which can be used to solve the dual band system without any assumptions therefore we can combine three spectral mivis bands to obtain simultaneous solutions for the three unknowns here the procedure for solving such a system is presented it is then demonstrated that a tir channel is required to better pinpoint solutions to the 2 components model finally the spatial and statistical characteristic of the resultant mivis derived temperature and flux distributions are introduced and statistics for each hot spot investigated

effects of viewing geometry on avhrr observations of volcanic thermal anomalies abstract we investigate the influence of viewing geometry and dynamic range of the advanced very high resolution radiometer avhrr sensor on detecting eruptions on poorly monitored volcanoes numerical models of sunwarmed flows and typical active features associated with hawaiian eruptions overturning lava lakes surface flows of three different sizes and lava tubes with skylights show that new lava flows at 1000 c can be identified at all scan angles if the area of the activity exceeds 60 m 2 given a background temperature of 20 c more difficult is the detection of small breakouts of lava flows or tube fed flows when these features lie towards the edge of the swath because of the dynamic range and gain setting of the sensor bands 3 4 and 5 saturate at 49 c it is possible that similar thermal signatures may be produced when inactive flows are heated by the sun the ability of the avhrr to detect on going activity in hawaii in july 1991 is tested by comparing landsat thematic mapper and nadir avhrr scenes obtained within 3 5 hours of each other for an active pahoehoe flow field with a well developed tube system this comparison shows that within the area of thermally alarmed avhrr pixels

thirty years of satellite derived lava discharge rates at etna implications for steady volumetric output 1 we present a 30 year long data set of satellite derived time averaged lava discharge rates tadr for mount etna volcano sicily italy spanning 1980 2010 and comprising 1792 measurements during 23 eruptions we use this to classify eruptions on the basis of magnitude and intensity as well as the shape of the tadr time series which characterizes each effusive event we find that while 1983 1993 was characterized by less frequent but longer duration effusive eruptions at lower tadrs 2000 2010 was characterized by more frequent eruptions of shorter duration and higher tadrs however roughly the same lava volume was erupted during both of these 11 year long periods so that the volumetric output was linear over the entire 30 year period increasing at a rate of 0 8 m3 s 1 between 1980 and 2010 the cumulative volume record can be extended back in time using data available in the literature this allows us to assess etna s output history over 5 centuries and to place the current trend in historical context we find that output has been stable at this rate since 1971 at this time the output rate changed from a low discharge rate phase which had characterized the period 1759 to 1970 to a high discharge rate phase this new phase had the same output rate as the high discharge rate phase that characterized the period 1610 1669 the 1610 1669 phase ended with the most voluminous eruption of historic times

thermal distributions of hot volcanic surfaces constrained using three infrared bands of remote sensing data infrared remote sensing provides a means for radiometry of hot volcanic features previously two spectral band measurements have been combined to solve simple 2 component models of lava surface temperatures however pixel dimensions often exceed the widths of lava bodies in such cases 3 component models are more realistic here a procedure for solving such a model from three infrared observations is presented it is then demonstrated using thematic mapper simulator data recorded over mount etna italy in 1991 by constraining temperatures and pixel filling fractions of the three different thermal components in this way improved estimates of radiant emittance can be obtained the techniques described could be applied to satellite data of volcanic and other hot spots including fires

a simple explanation for the space based calculation of lava eruption rates abstract knowing how lava effusion rates vary during basaltic eruptions can be of great significance when trying to provide preliminary forecasts regarding how far lava will flow however problems exist in accurately determining effusion rates using conventional field based techniques to ameliorate this problem harris et al j geophys res 102 1997 7985 8003 bull volcanol 59 1997 49 64 j volcanol geotherm res 102 2000 237 269 developed a method for determining effusion rates using infrared satellite data and showed how the method could be used to provide realistic estimates of effusion rates repeatedly during several eruptions at kilauea hawai i krafla iceland etna and stromboli italy harris et al j geophys res 102 1997 7985 8003 bull volcanol 59 1997 49 64 indicate that their method allows instantaneous lava effusion rates to be determined thermodynamically by equating the amount of heat lost by an active lava flow derived from the satellite data to the amount of heat liberated by the cooling mass of lava the purpose of this paper is to provide a simpler alternative explanation we find that rather than being used to calculate heat loss harris et al j geophys res 102 1997 7985 8003 bull volcanol 59 1997 49 64 j volcanol geotherm res 102 2000 237 269 actually use the satellite data to estimate the area of active lava present within the satellite s field of view at the movement of data acquisition thus changes in the effusion rates they present can only be proportional to changes in this area the active flow areas were then multiplied by a constant the value of which is obtained from a crude approximation of the lava flows heat balance crucially the absolute value of this term falls within the range of an empirically derived parameter that was found by pieri and baloga j volcanol geotherm res 30 1986 29 45 to explain strong linear correlations between eruption rate i e the time averaged effusion rate and lava flow area for 34 historic hawaiian flows as a result we find that the method of harris et al j geophys res 102 1997 7985 8003 does not yield instantaneous effusion rates but instead provides a valid and useful way to estimate average effusion rates i e the eruption rate from measurements of flow area

automated volcanic eruption detection using modis abstract the moderate resolution imaging spectroradiometer modis flown on board nasa s first earth observing system eos platform terra offers complete global data coverage every 1 2 days at spatial resolutions of 250 500 and 1000 m its ability to detect emitted radiation in the short 4 m and long 12 m wave infrared regions of the electromagnetic spectrum combined with the excellent geolocation of the image pixels 200 m makes it an ideal source of data for automatically detecting and monitoring high temperature volcanic thermal anomalies this paper describes the underlying principles of and results obtained from just such a system our algorithm interrogates the modis level 1b data stream for evidence of high temperature volcanic features once a hotspot has been identified its details location emitted spectral radiance satellite observational parameters are written to an ascii text file and transferred via file transfer protocol ftp to the hawaii institute of geophysics and planetology higp where the results are posted on the internet http modis higp hawaii edu the global distribution of volcanic hotspots can be examined visually at a variety of scales using this website which also allows easy access to the quantitative data contained in the ascii files themselves we outline how the algorithm has proven robust as a hotspot detection tool for a wide range of eruptive styles at both permanently and sporadically active volcanoes including soufriere hills montserrat popocatepetl mexico bezymianny russia and merapi java amongst others we also present case studies of how the system has allowed the onset development and cessation of discrete eruptive events to be monitored at nyamuragira congo piton de la fournaise reunion island and shiveluch russia

a chronology of the 1991 to 1993 mount etna eruption using advanced very high resolution radiometer data implications for real time thermal volcano monitoring between december 1991 and march 1993 a continuous effusive eruption at mount etna built a 7 6 km2 lava flow field flows extended to within 1 km of the town of zafferana before a successful artificial diversion was carried out higher up the volcano during this eruption the spaceborne advanced very high resolution radiometer avhrr acquired 308 images on which the activity could be detected since these data can be freely and directly available such coverage potentially allows regular real time monitoring ground observations and a flow map that we produced using a spot image and electronic distance measurement allowed us to develop and test data extraction techniques avhrr radiance maps were consistent with known locations of surface activity these documented the transition from channel to tube fed phases the changing threat to zafferana and flow diversion quantitative analysis of the avhrr data enabled estimation of active lava area thermal flux effusion rates and total flow field volume our estimates for eruption rate and total flow field volume 5 6 to 7 6 m3 s and 220 106 to 300 106 m3 respectively are in agreement with published ground based estimates of 5 8 m3 s and 235 106 m3 these correlations demonstrate the high degree of confidence that can now be placed in interpretations of avhrr time series for eruptions where ground based data are scanty

an emergent strategy for volcano hazard assessment from thermal satellite monitoring to lava flow modeling abstract spaceborne remote sensing techniques and numerical simulations have been combined in a web gis framework lav hazard to evaluate lava flow hazard in real time by using the hotsat satellite thermal monitoring system to estimate time varying tadr time averaged discharge rate and the magflow physics based model to simulate lava flow paths the lav hazard platform allows timely definition of parameters and maps essential for hazard assessment including the propagation time of lava flows and the maximum run out distance we used lav hazard during the 2008 2009 lava flow forming eruption at mt etna sicily italy we measured the temporal variation in thermal emission up to four times per hour during the entire duration of the eruption using seviri and modis data the time series of radiative power allowed us to identify six diverse thermal phases each related to different dynamic volcanic processes and associated with different tadrs and lava flow emplacement conditions satellite derived estimates of lava discharge rates were computed and integrated for the whole period of the eruption almost 14 months showing that a lava volume of between 32 and 61 million cubic meters was erupted of which about 2 3 was emplaced during the first 4 months these time varying discharge rates were then used to drive magflow simulations to chart the spread of lava as a function of time tadrs were sufficiently low 3 s that no lava flows were capable of flowing any great distance so that they did not pose a hazard to vulnerable agricultural and urban areas on the flanks of etna

analysis of volcanic activity patterns using modis thermal alerts we investigate eruptive activity by analysis of thermal alert data from the modis moderate resolution imaging spectrometer thermal infrared satellite instrument detected by the modvolc modis volcano alert algorithm these data are openly available on the internet and easy to use we show how such data can plug major gaps in the conventional monitoring record of volcanoes in an otherwise generally poorly documented region melanesia including characterising the mechanism of lava effusion at pago demonstrating an earlier than realised onset of lava effusion at lopevi extending the known period of lava lake activity at ambrym and confirming ongoing activity at bagana langila and tinakula we also add to the record of activity even at some generally better monitored volcanoes in indonesia but point out that care must be taken to recognise and exclude fires