accessory minerals and subduction zone metasomatism a geochemical comparison of two melanges washington and california u s a abstract the ability of a subducted slab or subducted sediment to contribute many incompatible trace elements to arc source regions may depend on the stabilities of accessory minerals within these rocks which can only be studied indirectly in contrast the role of accessory minerals in lower t and p metasomatic processes within paleo subduction zones can be studied directly in subduction zone metamorphic terranes the gee point iron mountain locality of the shuksan metamorphic suite north cascades washington state is a high t melange of metamafic blocks in a matrix of meta ultramafic rocks this melange is similar in geologic setting and petrology to the upper part of an unnamed amphibolite unit of the catalina schist santa catalina island southern california both are interpreted as shear zones between mantle and slab rocks that formed during the early stages of subduction some garnet amphibolite blocks from the gee point iron mountain locality display trace element enrichments similar to those in counterparts from the catalina schist some catalina blocks are highly enriched in th rare earth elements ree the high field strength elements ti nb ta zr and hf hfse u and sr compared to mid ocean ridge basalt morb and to other garnet amphibolite blocks in the same unit textural and geochemical data indicate that accessory minerals of metamorphic origin control the enrichment of th ree and hfse in blocks from both areas the mg rich rinds around blocks and the meta ultramafic matrix from both melanges are highly enriched in a large number of trace elements compared to harzburgites dunites and serpentinites evidence for recrystallization or formation of accessory minerals in the former rocks suggests that these minerals control some of the trace element enrichments data from the gee point and catalina melanges suggest that the accessory minerals titanite rutile apatite zircon and ree rich epidote play a significant role in the enrichment of trace elements in both mafic and ultramafic rocks during subduction related fluid rock interaction mobilization of incompatible elements and deposition of such elements in the accessory minerals of mafic and ultramafic rocks may be fairly common in fluid rich metamorphic environments in subduction zones

monitoring active volcanism with the autonomous sciencecraft experiment on eo 1 abstract the ability to monitor and rapidly react to remote detection of volcanic activity has been greatly improved through use of the autonomous sciencecraft experiment ase an advanced software application installed on a spacecraft in earth orbit ase is a nasa new millennium program experiment demonstrating science driven autonomous command and control of a spacecraft flying on the earth observing 1 eo 1 spacecraft ase successfully detected thermal emission from the mt erebus lava lake on 7 may 2004 having analyzed a hyperion hyperspectral data product on board the spacecraft eo 1 was re tasked by ase to obtain a follow up observation 7 h later and sent a notification of detection of volcanic activity to the ground the entire process was carried out autonomously initial acquisition to receipt on the ground of the positive detection took less than 3 h a process that without ase would have taken weeks the ase thermal classifier has detected several styles of effusive volcanic activity active lava lakes pahoehoe flow fields open channel flows and lava domes ase successfully demonstrated that science driven spacecraft operation greatly enhances science return per returned byte through the identification of the most valuable data allowing prioritization of downlink products and the discarding of null data sets this technology has applications on missions elsewhere in the solar system modified thermal classifiers can be used for detecting and monitoring active volcanism on the jovian satellite io the neptunian moon triton and searching for active volcanism on mars and icy satellites the success of ase is an incentive for future instrument and mission designers to consider on board data processing requirements especially data storage capacity number of processors and processor speed and ram in order to take advantage of this flight proven technology

detrital zircon constraints on terrane ages and affinities and timing of orogenic events in the san juan islands and north cascades washington detrital zircon geochronology of this report pertains to cretaceous orogeny in northwest washington an event that involved blueschist metamorphism and emplacement of nappes in the san juan islands northwest cascades thrust system and continental arc magmatism and associated barrovian metamorphism in the neighboring coast plutonic complex structurally low in the thrust system quartzose gneiss of the yellow aster complex yields an entirely precambrian suite of detrital zircons with an age pattern that is similar to that of ordovician miogeoclinal rocks and the outboard yukon tanana yreka and shoo fly terranes elsewhere in the cordillera midway in the nappe pile of the northwest cascades sandstone in the bell pass melange has a zircon age population of 110 ma an age that together with the spectrum of exotic materials associated with the sandstone suggests the melange was a major zone of dislocation during mid cretaceous nappe emplacement at a high level in the thrust system are nappes of the fida

review of the utility of infrared remote sensing for detecting and monitoring volcanic activity with the case study of shortwave infrared data for lascar volcano from 2001 2005 this chapter provides a historical review of the use of infrared remote sensing for the monitoring of volcanic activity it 1 examines the theoretical basis for infrared observations of thermally anomalous volcanic features 2 presents the various sensors that have been used and are currently available and 3 describes the techniques that have been developed to analyse such data the chapter ends with a case study of data derived from advanced spaceborne thermal emission and reflection radiometer shortwave infrared observations of lascar volcano in chile this case study aims to highlight the utility of infrared observations in volcano logical studies assessing the various techniques that can be used and examining the different factors which influence these analyses the chapter ends discussing future prospects for volcanic infrared remote sensing

infrared image analysis of volcanic thermal features lascar volcano chile 1984 1992 fifteen landsat thematic mapper tm images of lascar volcano chile recorded between december 1984 and april 1992 document the evolution of a lava dome within the summit crater four of the scenes were acquired at night in every image the two short wavelength infrared bands 5 and 7 have detected thermal radiation from the volcano as a consequence of the planck distribution function the relative response of these two channels depends on the proportions of very hot 600 c surfaces occupying tiny pixel areas and broader regions at moderate temperatures 280 c intercomparison of bands 5 and 7 thereby provides a means for interpreting tm thermal anomalies even in the absence of ground observations pronounced changes in the configuration and intensity of the lascar anomaly suggest that the volcano has experienced at least two cycles of lava dome activity since 1984 the first of these progressed through a cooling period possibly reflecting a reduced flux of magmatic volatiles at the surface and culminated in an explosive eruption on september 16 1986 which appears to have completely destroyed the inferred lava dome the tm data indicate that a new dome had been emplaced by november 1987 more than 15 months before it was first discovered by local observers lascar s style of cyclical effusive and explosive activity is typical of many volcanoes and the remote sensing techniques presented herein could be applied elsewhere

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

blocky regularization schemes for full waveform inversion with ill posed inverse problems such as full waveform inversion regularization schemes are needed to constrain the solution whereas many regularization schemes end up smoothing the model an undesirable effect with fwi where high resolution maps are sought blocky regularization does not it identifies and preserves strong velocity contrasts leading to step like functions these models might be needed for imaging with wave equation based techniques such as reverse time migration or for reservoir characterization enforcing blockiness in the model space amounts to enforcing a sparse representation of discontinuities in the model sparseness can be obtained using the 1 norm or cauchy function which are related to long tailed probability density functions detecting these discontinuities with vertical and horizontal gradient operators helps constraining the model in both directions blocky regularization can also help recovering higher wavenumbers that the data used for inversion would allow thus helping controlling the cost of fwi while the cauchy function yields blockier models both 1 and cauchy attenuate illumination and inversion artifacts

geochemistry of the shuksan greenschists and blueschists north cascades washington variably fractionated and altered metabasalts of oceanic affinity the shuksan schist comprises a structurally coherent metabasaltic member of the easton formation the uppermost allochthon shuksan thrust plate in the thrust system of the western north cascades of washington state late jurassic metamorphism at moderately high p t produced interlayering of actinolite bearing greenschist assemblages with blue amphibole bearing rocks major and trace element analyses of twelve greenschist and blueschist samples have been used to establish similarities between the basaltic protolith and moderately to strongly fractionated type i morb to distinguish the effects of seafloor alteration superimposed on the primary igneous chemistry and to evaluate the origin and nature of the chemical controls which produced the two mineral assemblages

io s volcanism thermo physical models of silicate lava compared with observations of thermal emission abstract analyses of thermal infrared outbursts from the jovian satellite io indicate that at least some of these volcanic events are due to silicate lava analysis of the january 9 1990 outburst indicates that this was an active eruption consisting of a large lava flow with mass eruption rate of order 10 5 m 3 sec 1 and a sustained area at silicate liquidus temperatures this is interpreted as a series of fire fountains along a rift zone a possible alternative scenario is that of an overflowing lava lake with extensive fire fountaining the january 9 1990 event is unique as multispectral observations with respect to time were obtained in this paper a model is presented for the thermal energy lost by active and cooling silicate lava flows and lakes on io the model thermal emission is compared with earth based observations and voyager iris data the model a provides an explanation of the thermal anomalies on io s surface b provides constraints on flow behavior and extent and infers some flow parameters and c determines flow geometry and change in flow size with time and the temperature of each part of the flow or lava lake surface as a function of its age models of heat output from active lava flows or inactive but recently emplaced lava flows or overturning lava lakes alone are unable to reproduce the observations if the january 9 1990 event is the emplacement of a lava flow the equivalent of 27 such events per year would yield a volume of material sufficient if uniformly distributed to resurface all of io at a rate of 1 cm year

the thermal signature of volcanic eruptions on io and earth abstract we investigate a spectrum based technique to identify the style of active volcanic eruptions on jupiter s moon io thermal remote sensing of io has had to rely primarily on low spatial resolution data similar to low spatial resolution satellite data applied to detecting and charting the temporal evolution of terrestrial hot spots these terrestrial analyses use data from sensors designed to monitor the weather and sea surface temperature on io such low spatial resolution data are used to classify eruption styles modes of emplacement by means of several criteria related to the temporal evolution of the infrared spectrum associated with the eruptive activity at each hot spot which we term thermal signature we find that the ratio of the emission at 2 and 5 m and how this ratio changes with time is often diagnostic of eruption style even in low spatial resolution data tests using thermal data for terrestrial ground truth cases show that our classification system is valid on earth the results of our analysis can be used to aid in the design of future space based instruments that can be used for volcano monitoring on io as well as earth

amphibole compositions and metamorphic history of the rand schist and the greenschist unit of the catalina schist southern california the catalina schist and rand schist are two high p t terranes in southern california the catalina schist is correlated with the franciscan complex and occurs in the continental borderland it consists of a blueschist facies melange tectonically overlain by a greenschist unit which in turn is overthrust by an amphibolite unit the greenschist unit itself is inversely zoned from epidote amphibolite fades at the top through greenschist facies in the center to transitional blueschist greenschist facies at the base the rand schist is part of the eugeoclinal pelona orocopia schist terrane which lies interior to the present continental margin structurally beneath precambrian to mesozoic sialic basement the rand schist is inversely zoned from epidote amphibolite facies to transitional blueschist greenschist facies similar to the greenschist unit of the catalina schist

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

io evidence for silicate volcanism in 1986 infrared observations of io during the 1986 apparition of jupiter indicate that a large eruptive event occurred on the leading side of io on 7 august 1986 universal time measurements made at 4 8 8 7 and 20 micrometers suggest that the source of the event was about 15 kilometers in radius with a model temperature of 900 kelvin together with previously reported events these measurements indicate that high temperature volcanic activity on the leading side of io may be more frequent than previously thought the inferred temperature is significantly above the boiling point of sulfur in a vacuum 715 kelvin and thus constitutes strong evidence for active silicate volcanism on the surface of io

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

regularized elastic full waveform inversion using deep learning we thank y liu z wu and y choi for their helpful discussions we also thank e gasperikova a guitton and four anonymous reviewers for the effort put into the review of this paper we thank the king abdullah university of science technology kaust for its support and specifically the seismic wave analysis group members for their valuable insights for computer time this research used the resources of the supercomputing laboratory at kaust in thuwal saudi arabia we thank vecta oil and gas and especially b devault for the bigsky data and the helpful discussions

structural and metamorphic history of the shuksan metamorphic suite in the mount watson and gee point areas north cascades washington the blueschist facies shuksan metamorphic suite of the north cascades has relict stratigraphy and sediment composition suggesting that it is of oceanic origin broadly defined the first metamorphic event affecting the rocks which probably occurred on the sea floor is a static epidote metasomatism of wide extent the earliest penetrative structures l 1 s 1 formed during latest jurassic early cretaceous blueschist facies metamorphism which is inferred to have occurred during subduction in this event recrystallization and intense penetrative strain were closely linked late metamorphic isoclinal fold axes f 2 and later crenulations l 3 formed at high angles to the l 1 lineation f 2 folds reflect extreme shortening perpendicular to the axis of the shuksan belt microscopic textural relations indicate that ca amphibole not na amphibole was stable during the development of f 2 and suggest that these structures record events related to uplift of the suite l 1 and f 2 structures can be interpreted to indicate either that uplift was the result of a distinct tectonic event or that metamorphism and uplift were part of a continuous tectonic process with no change in the stress field final emplacement of the shuksan suite occurred along a fault system which at least locally is high angle and includes zones of tectonic melange

application of multi source waveform inversion to marine streamer data using the global correlation norm conventional multi source waveform inversion using an objective function based on the least square misfit cannot be applied to marine streamer acquisition data because of inconsistent acquisition geometries between observed and modelled data to apply the multi source waveform inversion to marine streamer data we use the global correlation between observed and modelled data as an alternative objective function the new residual seismogram derived from the global correlation norm attenuates modelled data not supported by the configuration of observed data and thus can be applied to multi source waveform inversion of marine streamer data we also show that the global correlation norm is theoretically the same as the least square norm of the normalized wavefield to efficiently calculate the gradient our method employs a back propagation algorithm similar to reverse time migration based on the adjoint state of the wave equation in numerical examples the multi source waveform inversion using the global correlation norm results in better inversion results for marine streamer acquisition data than the conventional approach

volcanic eruptions on io heat flow resurfacing and lava composition abstract we model an infrared outburst on io as being due to a large erupting lava flow which increased its area at a rate of 1 5 10 5 m 2 sec 1 and cooled from 1225 to 555 k over the 2 583 hr period of observation the inferred effusion rate of 3 10 5 m 3 sec 1 for this eruption is very high but is not unprecedented on the earth and is similar to the high eruption rates suggested for early lunar volcanism eruptions occur 6 of the time on io these eruptions provide ample resurfacing to explain io s lack of impact craters we suggest that the large total radiometric heat flow 10 14 w and the size and temperature distribution of the thermal anomalies mcewen et al 1992 bull am astron soc 24 935 veeder et al 1994 j geophys res 99 17 095 17 162 can be accounted for by a series of silicate lava flows in various stages of cooling we propose that the whole suite of io s currently observed thermal anomalies was produced by multiple high eruptive rate silicate flows within the past century

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

oxygen isotope geothermometry and stability of lawsonite and pumpellyite in the shuksan suite north cascades washington metamorphic temperatures of 330 400 c are inferred for rocks from the shuksan blueschist terrane in the north cascades washington the temperatures are calculated from 18o fractionations between coexisting quartz and magnetite using the equations of bottinga and javoy 1973 pressures of approximately 7 kilobars are indicated by the jadeite content of clinopyroxene coexisting with quartz albite published experimental and theoretical studies of the stability of lawsonite and pumpellyite are consistent with the oxygen isotope temperatures and occurrence of these minerals in the shuksan suite

on the retrieval of lava flow surface temperatures from infrared satellite data the dual band method has been widely used as the basis for determining lava surface temperatures from infrared satellite data the method is based on the assumption that such surfaces can be described in terms of two end member thermal components hot cracks within a thermally homogeneous crust the recent launch of the first orbiting hyperspectral imaging system hyperion on board the national aeronautics and space administration earth observing 1 eo 1 satellite heralds a new era of space based hy perspectral data collection that will allow more detailed models of lava flow surface temperatures to be developed and parameterized to this end we have analyzed thermal images of active pahoehoe lava flows collected on kilauea volcano hawaii by using a forward looking infrared flir 595 pm thermacam in order to assess the number of thermal components required to characterize the surface temperatures of active lava flow surfaces the flir images show that an active lava flow surface comprises a contin uum of temperatures that define distinctive temperature distribu tions numerical model results reveal that the two component dual band method fails to resolve any of the major properties of the temperature distributions contained in these data i e mode skew range or dispersion however modeling five to seven thermal components allows all significant properties of the subpixel tem perature distributions contained within the flir images to be de termined thus although the hyperspectral data provided by the eo 1 hyperion yield as many as 66 wavebands in the 0 5 2 5 mm atmospheric window useable data in 9 13 of these should be suf ficient to perform accurate temperature characterization of active lava flow surfaces from space

correlation of early cretaceous blueschists in washington oregon and northern california the protolith and metamorphic histories of early cretaceous blueschists that occur in washington oregon and california are remarkably similar these blueschists are the shuksan metamorphic suite of northwestern washington the condrey mountain schist of northern california and southern oregon and the pickett peak terrane of northern california and southwestern oregon we suggest that these bodies were coextensive during their formation dispersion of the blueschists occurred in late cretaceous time by lateral translation of up to 900 km along the continental margin in response to oblique plate convergence

observing iceland s eyjafjallajokull 2010 eruptions with the autonomous nasa volcano sensor web 1 between 24 march and 5 june 2010 the hyperion hyperspectral imager and advanced land imager ali on nasa s earth observing 1 eo 1 spacecraft obtained an unprecedented sequence of 50 observation pairs of the eruptions at fimmvor uhals and eyjafjallajokull iceland this high acquisition rate was possible only through the use of data flow streamlined by using the autonomously operating nasa volcano sensor web vsw the vsw incorporates notifications of volcanic activity from multiple sources to retask eo 1 and process hyperion data to extract eruption parameters from high spatial and spectral resolution visible and short wavelength infrared data physical changes in eruption style and magnitude were charted as the eruptions ran their course rapid data downlink and automatic data processing algorithms generated a variety of products which are compared with estimates from ground based observations and post eruption in situ measurements estimates of effusion rate from heat loss measurements underestimate actual effusion rate while still following broad eruption rate trends but are closer to in situ estimates for effusive eruptions fimmvor uhals than explosive ash rich eruptions eyjafjallajokull during the later stages of the 2010 eruption vsw generated products were rapidly delivered to end users in iceland to aid in the assessment of risk and hazard the success of the vsw led to icelandic meteorological office imo in situ sensors being incorporated into the vsw and in may 2011 an imo seismic alert autonomously triggered eo 1 observations of a new eruption at grimsvotn volcano finally the vsw demonstrates an autonomy driven multi asset spacecraft retasking and data processing system that maximizes science return a desirable capability for future nasa missions

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

emplacement and inflation of pahoehoe sheet flows observations and measurements of active lava flows on kilauea volcano hawaii inflated pahoehoe sheet flows have a distinctive horizontal upper surface which can be several hundred meters across and are bounded by steep monoclinal uplifts the inflated sheet flows we studied ranged from 1 to 5 m in thickness but initially propagated as thin sheets of fluid pahoehoe lava generally 20 30 cm thick individual lobes originated at outbreaks from the inflated front of a prior sheet flow lobe and initially moved rapidly away from their source velocities slowed greatly within hours due to radial spreading and to depletion of lava stored within the source flow as the outward flow velocity decreases cooling promotes rapid crustal growth at first the crust behaves plastically as pahoehoe toes form after the crust attains a thickness of 2 5 cm it behaves more rigidly and develops enough strength to retain incoming lava thus increasing the hydrostatic head at the flow front the increased hydrostatic pressure is distributed evenly through the liquid lava core of the flow resulting in uniform uplift of the entire sheet flow lobe initial uplift rates are rapid flows thicken to 1 m in 1 2 hours but rates decline sharply as crustal thickness increases and as outbreaks occur from the margins of the inflating lobe one flow reached a final thickness of nearly 4 m after 350 hr inflation data define power law curves whereas crustal cooling follows square root of time relationships the combination of data can be used to construct simple models of inflated sheet flows as the flow advances preferred pathways develop in the older portions of the liquid cored flow these pathways can evolve into lavatube systems within a few weeks formation of lava tubes results in highly efficient delivery of lava at velocities of several kilometers per hour to a flow front that may be moving 1 2 orders of magnitude slower if advance of the sheet flow is terminated the tube remains filled with lava that crystallizes in situ rather than draining to form the cave like lava tubes commonly associated with pahoehoe flows inflated sheet flows from kilauea and mauna loa are morphologically similar to some thick icelandic and submarine sheet flows suggesting a similar mechanism of emplacement the planar sheet like geometry of flood basalt flows may also result from inflation of sequentially emplaced flow lobes rather than nearly instantaneous emplacement as literal floods of lava

geometry microstructures and magnetic fabrics of kink bands in the darrington phyllite northwestern washington usa processes within fixed hinge kinking abstract field thin section and magnetic fabric analyses of monoclinal contractional kink bands in the darrington phyllite of northwestern washington usa provide evidence of kinematic evolution and microstructural processes during kinking relationships among internal external and rotation angles of kink bands suggest that rotation was a primary mechanism of kinking and a significant number of kink bands deviate from the ideal kink band geometry equal internal and external kink angles dilation spaces voids filled with unrecrystallized quartz and or calcite inside kink bands and along the boundaries are commonly observed in kink bands with unequal kink angles evidence for localized interlayer slip inside kink bands includes mica grains protruding into the hinge voids and stair step geometry of the voids interlayer slip allowed for rotation of the internal foliation during kinking pressure solution is not ubiquitous inside kink bands from the study area however significant pressure solution is associated with locked kink bands equal kink angles a new approach using the anisotropy of magnetic susceptibility ams shows that the magnetic fabric and susceptibility inside the kink bands differ more from the outside fabric than can be explained by simple rotation of the outside fabric into the kink attitudes combined our observations suggest that fixed hinge kinking operated at this location and that veining interlayer slip and pressure solution were the dominant deformation mechanisms

lava flows and cinder cones at barren island volcano india 2005 2017 a spatio temporal analysis using satellite images barren island volcano erupted during january february 2017 located near the andaman trench and over a subduction zone it is the only active volcano in india it comprises a prominent caldera within which there is a polygenetic intra caldera cinder cone system with a record of eruptive events which date back to eighteenth century 1787 1832 major eruptions occurred in 1991 1994 1995 2005 and since 2008 the volcano has been showing near continuous activity with periodic eruptions we used coarse spatial resolution fire products band i4 from suomi national polar orbiting partnership visible infrared imaging radiometer suite to detect days of eruption during the january february 2017 period moderate spatial resolution 23 5 m short wavelength infrared swir data of resourcesat 2 linear imaging self scanning sensor iii available for specific days during this period were used to verify signatures of volcanic eruption thermal infrared band data from the landsat series over the 2005 2017 periods were used to estimate the brightness temperature and location of the active vent within the polygenetic cinder cone field high spatial resolution images 1 5 8 m in the visible bands resourcesat 2 liss iv cartosat 1 and 2 were used to delineate the changes in overall morphology of the volcano and to identify an inner crater ring fault new paths of lava flow and the formation of a new cinder cone on the old crater these multi temporal data sets show significant changes in the paths of lava flows from 2005 to 2017 the observations also document periodic shifts in the location of effusive vents morphogenetic changes in recent eruptive phases of the barren island volcano were successfully delineated using a combination of multi temporal and multi resolution satellite images in visible swir and thermal infrared regions of the electromagnetic spectrum

high temperature silicate volcanism on jupiter s moon io infrared wavelength observations of io by the galileo spacecraft show that at least 12 different vents are erupting lavas that are probably hotter than the highest temperature basaltic eruptions on earth today in at least one case the eruption near pillan patera two independent instruments on galileo show that the lava temperature must have exceeded 1700 kelvin and may have reached 2000 kelvin the most likely explanation is that these lavas are ultramafic magnesium rich silicates and this idea is supported by the tentative identification of magnesium rich orthopyroxene in lava flows associated with these high temperature hot spots

the nasa volcano sensor web advanced autonomy and the remote sensing of volcanic eruptions a review abstract the volcano sensor web vsw is a globe spanning net of sensors and applications for detecting volcanic activity alerts from the vsw are used to trigger observations from space using the earth observing 1 eo 1 spacecraft onboard eo 1 is the autonomous sciencecraft experiment ase advanced autonomy software using ase has streamlined spacecraft operations and has enabled the rapid delivery of high level products to end users the entire process from initial alert to product delivery is autonomous this facility is of great value as a rapid response is vital during a volcanic crisis ase consists of three parts 1 science data classifiers which process eo 1 hyperion data to identify anomalous thermal signals 2 a spacecraft command language and 3 the continuous activity scheduling planning execution and replanning casper software that plans and replans activities including downlinks based on available resources and operational constraints for each eruption detected thermal emission maps and estimates of eruption parameters are posted to a website at the jet propulsion laboratory california institute of technology in pasadena ca selected products are emailed to end users the vsw uses software agents to detect volcanic activity alerts generated from a wide variety of sources on the ground and in space and can also be easily triggered manually

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

eruptive behavior of the marum mbwelesu lava lake vanuatu and comparisons with lava lakes on earth and io abstract observations from field remote sensing of the morphology kinematics and temperature of the marum mbwelesu lava lake in the vanuatu archipelago in 2014 reveal a highly active vigorously erupting lava lake active degassing and fountaining observed at the 50 m lava lake led to large areas of fully exposed lavas and rapid 5 m s movement of lava from the centers of upwelling outwards to the lake margins these rapid lava speeds precluded the formation of thick crust there was never more than 30 non translucent crust the lava lake was observed with several portable handheld low cost near infrared imagers all of which measured temperatures near 1000 c and one as high as 1022 c consistent with basaltic temperatures fine scale structure in the lava fountains and cooled crust was visible in the near infrared at 5 cm pixel from 300 m above the lake surface the temperature distribution across the lake surface is much broader than at more quiescent lava lakes peaking 850 c and is attributed to the highly exposed nature of the rapidly circulating lake this lava lake has many characteristics in common with other active lava lakes such as erta ale in ethiopia being confined persistent and high temperature however it was much more active than is typical for erta ale which often has 90 crust furthermore it is a good analogue for the persistent high temperature lava lakes contained within volcanic depressions on jupiter s moon io such as pele also believed from spacecraft and ground based observations to exhibit similar behavior of gas emission rapid overturn and fountaining

volcanism on io estimation of eruption parameters from galileo nims data 1 galileo near infrared mapping spectrometer nims data of volcanic thermal emission are analyzed to determine the power output of a number of ionian volcanoes from which are calculated volumetric eruption rates a two temperature model is used to determine surface temperatures and power output portions of prometheus and six other volcanoes are found to be in excess of 1100 k areas of prometheus are at temperatures close to 1500 k these are minimum eruption temperatures and are consistent with basaltic silicate volcanism for the 14 volcanoes in g1innspec01 volumetric eruption rates e are constrained between 3 and 300 m3 s for basaltic and ultramafic compositions actual e values lie between these limits the small crack fractions hot area to warm area ratio implied from these fits are indicative of a relatively quiescent eruption style such as the emplacement of a pahoehoe or a a flow field the volumetric eruption rates derived from the nims data are greater than those observed in similar styles of volcanism on earth it is apparent that for similar eruption styles the areal extent of activity is greater on io than on earth derived flow thicknesses range from 0 1 to 13 m

characterization of a sulfur rich arctic spring site and field analog to europa using hyperspectral data abstract a unique glacial spring system exists at borup fiord pass in the canadian high arctic emerging from a glacial surface and depositing elemental sulfur gypsum and calcite across a portion of the glacier the presence of sulfur springs associated with glacial ice is extremely rare in a terrestrial context and the resulting deposits may provide a field analog to non ice materials on the surface of europa spectral characterization of the supraglacial deposits in the visible near infrared vis nir range 0 4 2 5 m was carried out using reflectance spectra collected in situ using a field spectrometer during the 2006 field season these spectra while dominated by melting snow ice and sulfur show that some absorption features of the sulfates are shifted in wavelength with respect to library spectra due to the effects of mixing or temperature absorption features of calcite are largely absent potentially due to mineral partitioning effects within the deposits investigations into changes in mineralogy within the deposits over the course of the active season using data collected by the hyperion hyperspectral visible infrared spectrometer aboard the earth observing 1 spacecraft eo 1 were limited by low signal to noise snr ratios in the data although they indicate that sulfur is remaining stable this is confirmed by seasonal data on the extent of the deposits obtained using a classification algorithm running onboard the satellite which continued to detect the presence of sulfur until snow obscured the site ground truth for the observations is provided by mineralogical analyses obtained by x ray diffraction xrd measurements and laboratory reflectance spectra from 0 2 25 m obtained of samples returned from the site in 2006 we show that while sulfur the main constituent of the deposits is well represented in hyperion data minor constituents such as calcite and gypsum can be partially or entirely masked in the data in spite of these effects autonomous detection methods can be utilized to monitor the generation and extent of the deposits whose spectral properties show similarities with those of europa s non ice materials

considerations for effusive cryovolcanism on europa the post galileo perspective 1 cryovolcanic resurfacing is a popular mechanism to explain relatively young surface units on icy satellites of jupiter saturn uranus and neptune prior to the galileo data acquired between 1996 and 2001 europa was thought to have undergone significant cryovolcanic resurfacing facilitated by a global ocean beneath the icy surface however close examination of galileo data at resolutions much better than those of voyager images show that many of the features previously thought to be cryovolcanic are commonly best explained by other formative mechanisms including tectonism and diapirism in this study i present an examination of the characteristics of a variety of europan surface features for which effusive cryovolcanism is a possible origin including apparently lobate flows certain elliptical to circular lenticulae and low lying smooth low albedo surfaces a review of cryovolcanic eruption theory together with galileo data analysis of europan surface geology and composition indicates that cryovolcanism is a viable though not unequivocal explanation for some of these features some constraints on cryomagma properties and lithospheric structure are offered for these cases the presence of small volume low viscosity effusions is supported by observations and modeling some positive relief lenticulae could represent more viscous effusions although diapirism may be a preferable explanation however strong evidence is lacking for cryovolcanic resurfacing on a large scale on the basis of our experience with galileo images of europa and ganymede voyager era inferences for widespread cryovolcanism on icy satellites may be overstated and will need to be carefully reexamined in the light of new data from upcoming spacecraft missions

thermal signature eruption style and eruption evolution at pele and pillan on io the galileo spacecraft has been periodically monitoring volcanic activity on io since june 1996 making it possible to chart the evolution of individual eruptions we present results of coanalysis of near infrared mapping spectrometer nims and solid state imaging ssi data of eruptions at pele and pillan especially from a particularly illuminating data set consisting of mutually constraining near simultaneous nims and ssi observations obtained during orbit c9 in june 1997 the observed thermal signature from each hot spot and the way in which the thermal signature changes with time tightly constrains the possible styles of eruption pele and pillan have very different eruption styles from september 1996 through may 1999 pele demonstrates an almost constant total thermal output with thermal emission spectra indicative of a long lived active lava lake the nims pillan data exhibit the thermal signature of a pillanian eruption style a large vigorous eruption with associated open channel or sheet flows producing an extensive flow field by orbit c10 in september 1997 the high mass eruption rate high liquidus temperature at least 1870 k eruption at pillan is the best candidate so far for an active ultramafic magnesium rich komatiitic flow on io a style of eruption never before witnessed the thermal output per unit area from pillan is however consistent with the emplacement of large open channel flows magma temperature at pele is 1600 k if the magma temperature is 1600 k it suggests a komatiitic basalt composition the power output from pele is indicative of a magma volumetric eruption rate of 250 to 340 m3 s 1 although the pele lava lake is considerably larger than its terrestrial counterparts the power and mass fluxes per unit area are similar to active terrestrial lava lakes