deformation of the pacific north america plate boundary at queen charlotte fault the possible role of rheology published 2018 this article is a u s government work and is in the public domain in the usa the definitive version was published in journal of geophysical research solid earth 123 2018 4223 4242 doi 10 1002 2017jb014770

global near ir maps from gemini n and keck in 2010 with a special focus on janus patera and kanehekili fluctus abstract we have imaged io in the near infrared 1 5 m with adaptive optics on the 10 m w m keck ii and the gemini north telescopes we have constructed global maps from the data taken in 2010 although numerous hot spots are visible the maps are dominated by two volcanic centers loki patera and kanehekili fluctus we have examined in detail the thermal emission from janus patera and kanehekili fluctus using images obtained between 2003 and 2010 and have created a timeline of volcanic activity at these locations utilizing data from a wide variety of sources based on our data and this timeline we find that the thermal emission from janus patera is relatively steady indicative of an active lava lake the thermal emission from kanehekili fluctus however is quite variable and is indicative of the emplacement of extensive lava flows in 2010 the thermal emission from this location was 10 times higher than ever seen before indicative of a particularly voluminous eruption of lava

high resolution keck adaptive optics imaging of violent volcanic activity on io io the innermost galilean satellite of jupiter is a fascinating world data taken by voyager and galileo instruments have established that it is by far the most volcanic body in the solar system and suggest that the nature of this volcanism could radically differ from volcanism on earth we report on near ir observations taken in february 2001 from the earth based 10 m w m keck ii telescope using its adaptive optics system after application of an appropriate deconvolution technique mistral the resolution 100 km on io s disk compares well with the best galileo nims resolution for global imaging and allows us for the first time to investigate the very nature of individual eruptions on 19 february we detected two volcanoes amirani and tvashtar with temperatures differing from the galileo observations on 20 february we noticed a slight brightening near the surt volcano two days later it had turned into an extremely bright volcanic outburst the hot spot temperatures 1400 k are consistent with a basaltic eruption and being lower limits do not exclude an ultramafic eruption these outburst data have been fitted with a silicate cooling model which indicates that this is a highly vigorous eruption with a highly dynamic emplacement mechanism akin to fire fountaining its integrated thermal output was close to the total estimated output of io making this the largest ionian thermal outburst yet witnessed

io eruptions at pillan and the time evolution of pele and pillan from 1996 to 2015 abstract observations obtained with the near infrared camera nirc2 coupled to the adaptive optics system on the 10 m w m keck ii telescope on mauna kea hawaii on 14 august 2007 revealed an active and highly energetic eruption at pillan at 245 2 0 7 w and 8 5 0 5 s a one temperature blackbody fit to the data revealed a blackbody temperature of 840 40 k over an area of 17 km2 with a total power output of 500 gw using davies davies a g 1996 icarus 124 1 45 61 io flow model we find that the oldest lava present is less than 1 2 h old having cooled down from the eruption temperature of 1400 k to 710 k this young hot lava suggests that an episode of lava fountaining was underway in addition to an examination of this eruption we present data of the pele and pillan volcanoes obtained with the same instrument and telescope from 2002 through 2015 these data reveal another eruption at pillan on ut 28 june 2010 model fits to this eruption yield a blackbody temperature of 600 700 k over an area of 60 km2 radiating over 600 gw on ut 18 february 2015 an energetic eruption was captured by the infrared telescope facility irtf via mutual event occultations the eruption took place at 242 7 1 w and 12 4 1 s i e in the eastern part of pillan patera subsequent observations showed a gradual decrease in the intensity of the eruption images obtained with the keck telescope on 31 march and 5 may 2015 revealed that the locations of the eruption had shifted by 120 160 km to the nw in contrast to the episodicity of pillan pele has been persistent observed in every appropriate 4 7 m observation pele was remarkably consistent in its thermal emission from the galileo era through february 2002 when a blackbody temperature of 940 40 k and an area of 6 5 km2 was measured since that time however the radiant flux from what is likely a apparently large overturning lava lake has gradually subsided over the next decade by a factor of 4 while the location of the thermal source was moving back and forth between areas roughly 100 km to the w of the 2002 location and an area roughly 100 km to the se of the 2002 location

reconstruction of holocene coupling between the south american monsoon system and local moisture variability from speleothem δ18o and 87sr 86sr records abstract investigating controls on past variability of south american hydroclimate is critical to assessing its response to future warming scenarios 18o records from south america offer insight into past variability of the south american monsoon system sams the controls however on precipitation 18o values can be decoupled from precipitation amount at a given site and thereby limit local moisture condition reconstructions here we use a principal components analysis to assess the coherence of speleothem and lake core holocene 18o records in tropical and subtropical south america to evaluate the extent to which 18o variability reflects changes in sams intensity at different sites across the region the main mode of variability across holocene 18o records pc1 closely tracks austral summertime insolation consistent with existing work sites towards the periphery of the continent are heavily weighted on pc1 whereas interior sites as not further 18o variability at interior sites bear little similarity to each other and implicate controls beyond regional monsoon intensity on these 18o records further we develop speleothem 87sr 86sr records spanning the holocene from tamboril cave brazilian highlands paraiso cave eastern amazon basin jaragua cave mato grosso do sul plateau and botuvera cave atlantic coastal plain to investigate coupling between reconstructed monsoon variability reflected by pc1 and local moisture conditions interpreted from 87sr 86sr records we interpret speleothem 87sr 86sr variability as a proxy of local moisture conditions reflecting the degree of water rock interaction with the cave host rock as driven by variations in water residence time speleothem 87sr 86sr records from all the sites except botuvera cave do not co vary with pc1 suggesting that local moisture conditions do not necessarily follow variations in regional monsoon intensity at these interior sites these speleothem 87sr 86sr records generally suggest dry mid holocene conditions relative to the early and late holocene consistent with interpretations of other paleo moisture records in the region but timing of wet dry transitions varies between sites these results highlight that controls in addition to sams variability might influence 18o variability further our results suggest spatially variable local moisture conditions at interior sites that do not uniformly respond to regional monsoon intensity and stress the need for 18o independent reconstructions of moisture conditions

imaging of volcanic activity on jupiter s moon io by galileo during the galileo europa mission and the galileo millennium mission the solid state imaging ssi instrument provided the first high and medium resolution views of io as the galileo spacecraft closed in on the volcanic body in late 1999 and early 2000 while each volcanic center has many unique features the majority can be placed into one of two broad categories the promethean eruptions typified by the volcanic center prometheus are characterized by long lived steady eruptions producing a compound flow field emplaced in an insulating manner over a period of years of decades in contrast pillanian eruptions are characterized by large pyroclastic deposits and short lived but high effusion rate eruptions from fissures feeding open channel or open sheet flows both types of eruptions commonly have 100 km tall bright so2 rich plumes forming near the flow fronts and smaller deposits of red material that mark the vent for the silicate lavas

slump generated megachannels in the pliocene pleistocene glaciomarine yakataga formation gulf of alaska pliocene pleistocene megachannels as much as 400 m deep and several kilometers wide are exceptionally well exposed around the gulf of alaska coastal margin in glaciomarine sedimentary strata of the yakataga formation in the icy bay region stacked megachannels of the yakataga formation are filled predominantly with debris flow diamictites crudely stratified conglomerates and thinly bedded sandstone and mudstone turbidites detailed sedimentological and micropaleontological analyses of the megachannel deposits identified two distinct facies associations that represent channel margin and central channel fill depositional settings all facies types indicate deposition by sediment gravity flow processes and high rates of sediment supply in a tectonically active setting foraminiferal biofacies suggest deposition in inner neritic to upper bathyal water depths and vigorous transport of sediment from shallow to deeper water the yakataga formation megachannels probably formed as slump scars produced by the retrogressive failure and downslope slumping of rapidly deposited outer shelf upper slope sediments the intimate association of megachannels with thrust faults and folds suggests that initial slumping was triggered by tectonic tilting and high magnitude earthquakes megachannels have a relatively immature form and were probably short lived and filled rapidly with sediment gravity flow deposits megachannels of the yakataga formation provide a well exposed analog for megachannels formed in other tectonically active settings or passive margin settings characterized by high sedimentation rates there is little evidence to suggest that megachannel development is systematically related to episodes of sea level lowstand and a sequence stratigraphic context is difficult to identify

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

io volcanism seen by new horizons a major eruption of the tvashtar volcano jupiter s moon io is known to host active volcanoes in february and march 2007 the new horizons spacecraft obtained a global snapshot of io s volcanism a 350 kilometer high volcanic plume was seen to emanate from the tvashtar volcano 62 n 122 w and its motion was observed the plume s morphology and dynamics support nonballistic models of large io plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source in images taken in jupiter eclipse nonthermal visible wavelength emission was seen from individual volcanoes near io s sub jupiter and anti jupiter points near infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150 to 1335 kelvin range consistent with basaltic composition

the paleoclimatic significance of deformation structures in neoproterozoic successions abstract this paper reviews the different types of soft sediment deformation structures that can form in glacial and non glacial settings and explores the potential use of these structures in resolving long standing debates in paleoenvironmental reconstructions of neoproterozoic glacigenic successions soft sediment deformation structures are created when compressional gravitational or shear stress is applied to unlithified sediments during or shortly after deposition in subglacial or ice marginal glacial settings shear and compressional stress imparted by ice moving on top of a deformable substrate or advancing ice buldozing unlithified ice marginal sediments can result in a wide range of folding faulting and shear structures in glaciofluvial or stagnant ice marginal setting gravitational collapse and remobilization of sediments associated with the melting of buried ice can result in normal faulting and broad folding in glaciolacustrine or glaciomarine settings compressional shear and gravitational types of deformation structures can occur as a result of grounding ice or icebergs rapid sedimentation and reworking downslope associated with high sedimentation rates in non glacial settings similar deformation structures can form as a result of slope instability and reworking of sediments downslope rapid sedimentation seismic shaking wave induced shearing or loading in this context two case studies are presented to demonstrate the type of paleoenvironmental information that an analysis of deformation structures can provide in the first case study analysis of deformation in the port askaig formation scotland reveals a distinctive stratigraphic distribution of deformation structures the types of deformation observed together with their recurrence over several 100s of meters and their basinal context are used to infer a seismic origin for the deformation which in turn suggests a significant tectonic control on sedimentation atop a record of ice margin fluctuations in a glaciomarine setting in the second example analysis of deformation in the smalfjord formation northern norway provides strong evidence for deformation by active ice overriding glaciofluvial deposits the types of deformation in this example together with its complexity scale and associated facies provide the strongest case for ice marginal deformation in sum analysis of deformation structures together with analysis of structural geology stratigraphy facies and facies associations can provide additional constraints on paleoenvironmental conditions at the time of deposition which can help us refine or test paleoenvironmental models proposed for this critical time period in earth history

time variability of io s volcanic activity from near ir adaptive optics observations on 100 nights in 2013 2015 abstract jupiter s moon io is a dynamic target exhibiting extreme and time variable volcanic activity powered by tidal forcing from jupiter we have conducted a campaign of high cadence observations of io with the goal of characterizing its volcanic activity between aug 2013 and the end of 2015 we imaged io on 100 nights in the near infrared with adaptive optics on the keck and gemini n telescopes which resolve emission from individual volcanic hot spots during our program we made over 400 detections of 48 distinct hot spots some of which were detected 30 times we use these observations to derive a timeline of global volcanic activity on io which exhibits wide variability from month to month the timelines of thermal activity at individual volcanic centers have geophysical implications and will permit future characterization by others we evaluate hot spot detection limits and give a simple parameterization of the minimum detectable intensity as a function of emission angle which can be applied to other analyses we detected three outburst eruptions in august 2013 but no other outburst scale events were observed in the subsequent 90 observations either the cluster of events in august 2013 was a rare occurrence or there is a mechanism causing large events to occur closely spaced in time we also detected large eruptions though not of outburst scale within days of one another at kurdalagon patera and sethlaus gabija paterae in 2015 as was also seen in the galileo dataset the hot spots we detected can be separated into two categories based on their thermal emission those that are persistently active for 1 year or more at moderate intensity and those that are only briefly active are time variable and often reach large intensities a small number of hot spots in the latter category appear and subside in a matter of days reaching particularly high intensities although these are not bright enough to qualify as outbursts their thermal signatures follow the same pattern suggesting that a similar mechanism may be responsible for these events though at a smaller scale two eruptions seen at kurdalagon patera in january and april 2015 occurred simultaneously with a brightening of the neutral cloud and plasma torus which are sourced from io s atmosphere a plume at kurdalagon patera such as was seen by new horizons in 2007 could have been responsible for the influx of material that caused these brightenings

flow pattern within a permian submarine slump recorded by oblique folds and deformed fossils ulladulla south eastern australia the flow pattern within a slump in permian marine rocks of the southern sydney basin australia is recorded by folds and deformed fossils abundant brachiopod and bryzoan fossils in the slumped rocks are relatively undeformed but fossil crinoid stems have been deformed by relative rotation of individual ossicles measurement of the strain indicates that the deformation of the crinoids is consistent with flexural flow folding within the slump previous models assume that curved slump fold axes remain parallel to the enveloping bedding surface of a slump sheet detailed measurements of the orientation of slump folds in this study found fold axes to be oblique to bedding which is interpreted as a result of folds plunging downward towards the flanks of the slump or slump lobes in the present model fold axes are not generally parallel to the strike of the fold axial surface and this can explain differences between the orientations of slump fold axes and axial surfaces when these are used as directional indicators of slump movement

millennial scale precipitation changes in southern brazil over the past 90 000 years 1 a u th dated 90 000 year long speleothem oxygen isotope record from southern brazil anti correlates remarkably with the cave calcite records from eastern china but positively correlates with the speleothem record from northeastern brazil suggesting an interhemispheric anti phasing of rainfall on both millennial and orbital timescales likely related to displacement in the mean position of the intertropical convergence zone and associated asymmetry in hadley circulation the phase relationships among these records are consistent with the hypothesis that abrupt climate events during the last glacial period are triggered by oceanic circulation changes in the high latitudes and enhanced by tropical feedbacks

morphology and morphogenesis of a high latitude canyon the andoya canyon norwegian sea abstract the morphology of the high latitude andoya canyon in the norwegian sea was studied using multi beam bathymetry data the canyon excavation processes include sliding and slumping axial incision and gullying sliding and slumping has most frequently occurred in muddy sediments of the western sidewall due to canyon axial incision and undercutting and failures during infilling of a high relief terrain by alongslope transported sediments axial incision is inferred to be due to turbidity current erosion the turbidity currents were mainly the result of piracy of shelf sediments the eastern sidewall is dominated by gullies speculated to be the initial forms generated on a steep slope constructed from stiff poorly sorted glacigenic sediments from the present canyon morphology including the overall convex upwards form of the topographic long profile with a steep 20 25 upper headwall we favour a bottom up canyon development i e mass wasting and subsequent piracy of alongslope transported slope and shelf sediments in contrast to most other canyons the development of the andoya canyon was not only a result of side and headwall instability and axial incision most active during periods of high sediment transfer but also due to infilling of the canyon by sediments transported by alongslope flowing ocean currents and from the fennoscandian ice sheet at the shelf break there are little or no slide deposits covering the thalweg this leads us to suggest that the most recent process dominating within the canyon is turbidity current flushing and erosion inferred to have occurred during the holocene

influence of sediment transport dynamics and ocean floor morphology on benthic foraminifera offshore fraser island australia abstract the extensive longshore sediment transport system along the se margin of australia transports yearly 500 000 m 3 of sand from the gold coast of southern queensland north towards fraser island fraser island which consists of 203 km 3 of quartz sand is presently not increasing in size and north of the island quartz sand is replaced by carbonate sand recent multibeam sonar seafloor imagery and sediment analysis has established that the transported sand is being diverted by strong ebb tidal flow over the continental shelf edge onto the tasman abyssal plain through a series of active gullies that incised the continental slope foraminiferal distribution patterns on the shelf and slope are closely linked to the variable ocean floor morphology and associated physical processes in sample locations outside the continental slope gullies areas unaffected by downslope sediment transport foraminiferal assemblages gradually change in accordance with bathymetric zones and their prevailing ecological parameters species diversity evenness the proportion of infaunal species and the abundance of agglutinated taxa all increase with depth assemblages within gullies of the clastic sand transport route are significantly different estuarine and shelf species are transported over the shelf break and mix with typical slope species along the transport path resulting in continued high species diversities as the sediment and faunal load enters the abyssal plain a faunal portion continues to travel within the capricorn sea valley to over 4000 m depth the erosional nature of gullies results in reduction of agglutinated species subtle topographic features such as ridges or levees within the canyon and deep sea valley act as protection from the main erosional sand transport pathway and support the presence of fragile and erect suspension feeders foraminiferal distribution patterns would have received an entirely different biofacies interpretation without linking them to ocean floor processes as revealed through multibeam sonar imagery

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

satellite observations reveal little inter annual variability in the radiant flux from the mount erebus lava lake abstract satellite remote sensing represents a mature technology for long term monitoring of volcanic activity at mount erebus either independently or as a complement to field instrumentation observations made on 4290 discrete occasions over a six year period by nasa s moderate resolution imaging spectroradiometer modis indicate that the radiant flux from the volcano s summit crater and by inference the lava lake contained therein while variable on the time scale of days to weeks has varied little on an inter annual basis over this period the average radiant flux from the lake during this time was 15 mw with a maximum flux of 100 mw such heat flux time series have been shown to act as a reliable proxy for general levels of activity at erupting volcanoes around the world particularly when these time series are of a long duration the apparent stability of erebus power output is in marked contrast to fluxes observed at three other terrestrial volcanoes erta ale ethiopia nyiragongo democratic republic of congo and ambrym vanuatu which while also hosting active lava lakes all exhibit much greater variability in radiant flux over the same period of time the results presented in this paper are confluent with those obtained from geochemical considerations of the erebus degassing regime and confirm that remarkably stable open system volcanism appears to be characteristic of this long active volcano

ocean drilling program leg 178 antarctic peninsula sedimentology of glacially influenced continental margin topsets and foresets abstract ocean drilling program leg 178 february april 1998 drilled two sites sites 1097 and 1103 on the outer antarctic peninsula pacific continental shelf recovered strata are no older than late miocene or early pliocene site 1097 lies on the outer shelf within marguerite trough which is a major outlet for ice expanding seaward from the antarctic peninsula and reached a maximum depth drilled of 436 6 m below the sea floor mbsf seismic stratigraphic data show flat lying upper strata resting on strata that dip gently seaward uppermost strata to a depth of 150 mbsf were poorly recovered but data suggest they consist of diamictites containing reworked and abraded marine microfauna this interval is interpreted as having been deposited largely as till produced by subglacial cannibalization of marine sediments deformation till recording ice sheet expansion across the shelf underlying gently dipping strata show massive stratified and graded diamictite facies with common bioturbation and slump stuctures that are interbedded with laminated and massive mudstones with dropstones the succession contains a well preserved in situ marine microfauna typical of open marine and proglacial marine environments the lower gently dipping succession at site 1097 is interpreted as a complex of sediment gravity flows formed of poorly sorted glacial debris site 1103 was drilled in that part of the continental margin that shows uppermost flat lying continental shelf topsets overlying steeper dipping slope foresets seaward of a structural mid shelf high drilling reached a depth of 363 mbsf with good recovery in steeply dipping continental slope foreset strata foreset strata are dominated by massive and chaotically stratified diamictites interbedded with massive and graded sandstones and mudstones the sedimentary record and seismic stratigraphy is consistent with deposition on a continental slope from debris flows and turbidity currents released from a glacial source data from sites 1097 and 1103 suggest the importance of aggradation of the antarctic peninsula continental shelf by till deposition and progradation of the slope by mass flow this may provide a model for the interpretation of palaeozoic and proterozoic glacial successions that accumulated on glacially influenced continental margins

the variability of volcanic activity at zamama culann and tupan patera on io as seen by the galileo near infrared mapping spectrometer abstract zamama culann and tupan patera are three large persistent volcanic centers on the jovian moon io as part of an ongoing project to quantify contributions from individual volcanic centers to io s thermal budget we have quantified the radiant flux from all suitable observations made by the galileo near infrared mapping spectrometer nims of these volcanoes in some cases filling omissions in previous analyses at zamama after a long period of cooling we see a peak in thermal emission that corresponds with new plume activity subsequently toward the end of the galileo epoch thermal emission from zamama drops off in a manner consistent with a greatly reduced eruption rate and the cooling of emplaced flows culann exhibits possible episodic activity we present the full tupan patera nims dataset and derive new estimates of thermal output and temporal behavior eruption rates at these three volcanoes are on the order of 30 m 3 s 1 consistent with a previous analysis of nims observations of prometheus and nearly an order of magnitude greater than kilauea volcano hawai i earth s most active volcano we propose that future missions to the jovian system could better constrain activity at these volcanoes and others where similar styles of activity are taking place by obtaining data on a time scale of ideally at least one observation per day observations at similar or even shorter timescales are desirable during initial waxing phases of eruption episodes these eruptions are identifiable from their characteristic spectral signatures and temporal behavior

two new rare high effusion outburst eruptions at rarog and heno paterae on io observations obtained with the near infrared camera nirc2 coupled to the adaptive optics system on the 10 m w m keck ii telescope on mauna kea hawaii on 15 august 2013 at 15 30 ut revealed two large outburst class volcanic eruptions on io follow up observations five days later showed that both eruptions had substantially faded the most energetic eruption was at rarog patera at a location near 305 w 42 s a smaller one occurred further south at 310 w and 57 s close to heno patera total radiant fluxes at rarog patera on august 15 were of order 500 gw sr m at wavelengths between 2 and 4 m and close to 250 gw sr m at 1 6 m indicative of an effective temperature of 1040 k over an area of 120 km 2 and a total thermal emission of nearly 8 tw at heno patera the 4 m flux measured 250 gw sr m and 90 gw sr m at 2 2 m suggestive of an effective temperature of 720 k over an area of more than 300 km 2 and a total thermal emission of 5 6 tw fits of the davies davies a g 1996 icarus 124 1 45 61 io flow model indicate that these two eruptions are vigorous and the exposed surfaces are mostly very young no older than 4 5 min at rarog patera and a few hours at heno patera the model fits suggest that in both locations lava fountaining is taking place a highly energetic style of volcanism using follow up observations taken between august 20 and september 7 we estimate peak effusion rates between 5 10 4 and 10 5 m 3 s

near infrared monitoring of io and detection of a violent outburst on 29 august 2013 abstract we present initial data from our campaign to monitor io in the near infrared beginning in august 2013 using 3 8 m adaptive optics imaging at gemini n and 2 5 m disk integrated spectroscopy at nasa s irtf conducted during 2013 2014 these observations are coincident with the isas jaxa exceed mission s continuous monitoring of the io plasma torus and will enable the speculated effects of volcanic outgassing on the torus to be observed directly in addition to enabling an assessment of the frequency and properties of large scale outbursts on 29 august 2013 we detected a powerful eruption designated 201308c on io at 223 5 2 6 w 29 1 1 8 n emitting between 15 and 25 tw this event is one of the most powerful eruptions ever seen on io and falls into the rare outburst class this was the third eruption of this type seen on io in august 2013 an unprecedented occurrence also unprecedented was the charting of the decay in thermal emission over the subsequent days and weeks modeling of the outburst spectrum places a lower bound of 1200 1300 k on the eruption temperature and is suggestive of temperatures 1900 k or higher typically associated with ultramafic lava composition the eruption is likely a highly energetic high volume lava fountain event

permo carboniferous conglomerates in the trinity peninsula group at view point antarctic peninsula sedimentology geochronology and isotope evidence for provenance and tectonic setting in gondwana field observations from the trinity peninsula group at view point on the antarctic peninsula indicate that thick southward younging and overturned clastic sedimentary rocks comprising unusually coarse conglomeratic lenses within a succession of fine grained sandstone mudstone couplets are the deposits of debris and turbidity flows on or at the foot of a submarine slope three detrital zircons from the sandstone mudstone couplets date deposition at 302 3 ma at or shortly after the carboniferous permian boundary conglomerates predominantly consist of quartzite and granite and contain boulders exceeding 500 mm in diameter zircons from granitoid clasts and a silicic volcanic clast yield u pb ages of 466 3 ma 373 5 ma and 487 4 ma respectively and have corresponding average ehft values between 0 3 and 7 6 a quartzite clast conglomerate matrix and sandstone interbedded with the conglomerate units have broadly similar detrital zircon age distributions and hf isotope compositions the clast and detrital zircon ages match well with sources within patagonia however the age of one granite clast and the ehf characteristics of some detrital zircons point to a lesser south africa or ellsworth mountain like contribution and the quartzite and granite dominated composition of the conglomerates is similar to upper palaeozoic diamictites in the ellsworth mountains unlike detrital zircons large conglomerate clasts limit possible transport distance and suggest sedimentation took place on or near the edge of continental crust comparison with other upper palaeozoic to mesozoic sediments in the antarctic peninsula and patagonia including detrital zircon composition and the style of deformation suggests deposition of the trinity peninsula group in an upper plate basin on an active margin rather than a subduction related accretionary setting with slow extension and rifting punctuated by short periods of compression

benthic foraminiferal faunas reveal transport dynamics and no analog environments on a glaciated margin gulf of alaska abstract paleoecological and faunal based paleoenvironmental studies rely on fossil assemblages that have high fidelity to the once living faunas and to the target environment however many sedimentary records contain multiple depositional facies transported sediments with their associated fossils and varying degrees of taphonomic alteration which can confound interpretations here we combine measures of compositional fidelity modern analog faunal methods sedimentary analyses and taphonomic scoring to examine the history of sediment transport and environmental change in a 60 000 year continental slope record from the gulf of alaska using benthic foraminiferal assemblages these assemblages generally have good compositional fidelity to modern faunas in the gulf of alaska but are not necessarily faithful to the modern continental slope fossil benthic foraminiferal assemblages with modern analogs from shelf and slope environments are intercalated downcore suggesting episodes of sedimentary transport to the slope site fossil assemblages without modern analogs in this record appear ecologically rather than taphonomically derived and thus suggest that the range of past environmental variation in the gulf of alaska is not captured by modern spatial variation these no analog fossil assemblages are allied with analog assemblages using similarity in taxonomic and sedimentary characteristics permitting analysis of environmental change in shelf and slope settings from a single core the faunal composition of the no analog assemblages suggests the gulf of alaska slope experienced lower oxygen conditions in the past than observed in the modern gulf lower productivity is also suggested for some shelf samples however geochemical proxy data are necessary to fully interpret the no analog assemblages

active volcanism on io as seen by galileo ssi abstract active volcanism on io has been monitored during the nominal galileo satellite tour from mid 1996 through late 1997 the solid state imaging ssi experiment was able to observe many manifestations of this active volcanism including 1 changes in the color and albedo of the surface 2 active airborne plumes and 3 glowing vents seen in eclipse about 30 large scale tens of kilometers surface changes are obvious from comparison of the ssi images to those acquired by voyager in 1979 these include new pyroclastic deposits of several colors bright and dark flows and caldera floor materials there have also been significant surface changes on io during the galileo mission itself such as a new 400 km diameter dark pyroclastic deposit around pillan patera while these surface changes are impressive the number of large scale changes observed in the four months between the voyager 1 and voyager 2 flybys in 1979 suggested that over 17 years the cumulative changes would have been much more impressive there are two reasons why this was not actually the case first it appears that the most widespread plume deposits are ephemeral and seem to disappear within a few years second it appears that a large fraction of the volcanic activity is confined to repeated resurfacing of dark calderas and flow fields that cover only a few percent of io s surface the plume monitoring has revealed 10 active plumes comparable to the 9 plumes observed by voyager one of these plumes was visible only in the first orbit and three became active in the later orbits only the prometheus plume has been consistently active and easy to detect observations of the pele plume have been particularly intriguing since it was detected only once by ssi despite repeated attempts but has been detected several times by the hubble space telescope at 255 nm pele s plume is much taller 460 km than during voyager 1 300 km and much fainter at visible wavelengths prometheus type plumes 50 150 km high long lived associated with high temperature hot spots may result from silicate lava flows or shallow intrusions interacting with near surface so2 a major and surprising result is that 30 of io s volcanic vents glow in the dark at the short wavelengths of ssi these are probably due to thermal emission from surfaces hotter than 700 k with most hotter than 1000 k well above the temperature of pure sulfur volcanism active silicate volcanism appears ubiquitous there are also widespread diffuse glows seen in eclipse related to the interaction of energetic particles with the atmosphere these diffuse glows are closely associated with the most active volcanic vents supporting suggestions that io s atmopshere is dominated by volcanic outgassing globally volcanic centers are rather evenly distributed however 14 of the 15 active plumes seen by voyager and or galileo are within 30 of the equator and there are concentrations of glows seen in eclipse at both the sub and antijovian points these patterns might be related to asthenospheric tidal heating or tidal stresses io will continue to be observed during the galileo europa mission which will climax with two close flybys of io in late 1999

basinal setting and origin of thick 1 8 km mass flow dominated grand conglomerat diamictites kamoa democratic republic of congo resolving climate and tectonic controls during neoproterozoic glaciations

variability and geologic associations of volcanic activity on io in 2001 2016 since the end of the galileo epoch ground based observations have been crucial for the continued monitoring and characterization of volcanic activity on jupiter s moon io we compile and analyze observations from the keck and gemini north telescopes between 2001 and 2016 including new and published observations from 2003 2004 2005 2007 2008 2009 2011 2012 2013 and 2016 a total of 88 distinct hot spot sites were detected over the 15 year period 82 of which were detected multiple times and 24 of which were not detected by galileo at thermal infrared wavelengths 1 5 m a variety of analytical methods are utilized to investigate the detections of active volcanism as a surface expression of interior heating geologic associations of hot spots including patera type lava flow type and proximity to mountainous regions are made using the usgs published global geologic map of io williams 2011 we also provide a summary of outburst scale events along with the slightly less bright but more frequent mini outbursts described by de kleer and de pater 2016a we investigate the spatial distribution of volcanic activity on io using nearest neighbor mean pairwise spacing and mean latitude statistics with various classification schemes the analysis confirms previous findings in that the heat dissipation appears to be primarily concentrated in the asthenosphere resulting in a high time averaged surface heat flux at low latitudes our observations show significant spatial deviations do exist from the asthenosphere heat dissipation model while also suggesting a deeper source of magma ascent to be present as well supporting conclusions from previous analyses of primarily spacecraft data veeder et al 2012 hamilton 2013 davies et al 2015 from a temporal perspective there are signs of significant variations in the distribution of global heat flux as volcanoes undetected and probably dormant during the galileo encounters subsequently erupted and remained active during our observations we also use the on 3 8 m radiant intensity timelines of individual hot spots along with the distribution of extensive lava fields in relation to detected activity as a means to investigate possible connections between hot spots and short timescale spatio temporal variations in the global heat flux distribution we conclude that while the global heat flux distribution remains relatively constant over decadal timescales there is evidence that significant deviations do occur potentially as a result of mountain forming processes or triggering mechanisms between eruptions

relation between the subducting plate and seismicity associated with the great 1964 alaska earthquake tectonic studies of the great 1964 alaska earthquake have underappreciated the nature of the subducted plate in influencing seismicity we compare seismological observations in the prince william and kodiak areas that ruptured during this earthquake with the corresponding morphology and structure of the subducting plate the upper plate geology prince william terrane and velocity structure are the same in both areas in the prince william area where the yakutat terrane subducted the energy released and coupling were stronger than above the kodiak subduction zone where thick trench sediment subducts the conjecture that lower plate character or the amount of subducted sediment affects coupling helps explain variability in seismology geodetic inversions and the horizontal velocity of gps stations

charting thermal emission variability at pele janus patera and kanehekili fluctus with the galileo nims io thermal emission database nited abstract using the nims io thermal emission database nited a collection of over 1000 measurements of radiant flux from io s volcanoes davies a g et al 2012 geophys res lett 39 l01201 doi 10 1029 2011gl049999 we have examined the variability of thermal emission from three of io s volcanoes pele janus patera and kanehekili fluctus at pele the 5 m thermal emission as derived from 28 night time observations is remarkably steady at 37 10 gw m 1 re affirming previous analyses that suggested that pele an active rapidly overturning silicate lava lake janus patera also exhibits relatively steady 5 m thermal emission 20 3 gw m 1 in the four observations where janus is resolved from nearby kanehekili fluctus janus patera might contain a pele like lava lake with an effusion rate qf of 40 70 m3 s 1 it should be a prime target for a future mission to io in order to obtain data to determine lava eruption temperature kanehekili fluctus has a thermal emission spectrum that is indicative of the emplacement of lava flows with insulated crusts effusion rate at kanehekili fluctus dropped by an order of magnitude from 95 m3 s 1 in mid 1997 to 4 m3 s 1 in late 2001

observations and temperatures of io s pele patera from cassini and galileo spacecraft images abstract pele has been the most intense high temperature hotspot on io to be continuously active during the galileo monitoring from 1996 2001 a suite of characteristics suggests that pele is an active lava lake inside a volcanic depression in 2000 2001 pele was observed by two spacecraft cassini and galileo the cassini observations revealed that pele is variable in activity over timescales of minutes typical of active lava lakes in hawaii and ethiopia these observations also revealed that the short wavelength thermal emission from pele decreases with rotation of io by a factor significantly greater than the cosine of the emission angle and that the color temperature becomes more variable and hotter at high emission angles this behavior suggests that a significant portion of the visible thermal emission from pele comes from lava fountains within a topographically confined lava body high spatial resolution nightside images from a galileo flyby in october 2001 revealed a large relatively cool

precipitation over south america during the last glacial maximum an analysis of the amount effect with a water isotope enabled general circulation model low latitude paleoclimate records from speleothem 18o measurements are often considered to reflect variations in precipitation amounts here we test this interpretation with a water isotope enabled atmospheric general circulation model comparing modern and last glacial maximum lgm controls on the 18op in brazil we argue that the 18op is determined by the contributions from local evaporation high 18o versus water vapor convergence to the region low 18o our analysis indicates that the amount effect commonly used to infer precipitation amount from 18op in low latitude regions works only where the isotopic composition of incoming vapor stays relatively constant such as in coastal regions of the subtropics if the isotopic composition of incoming vapor has changed as a result of the variations in the upstream rainout 18op cannot be used to estimate local precipitation our analysis supports the increase of precipitation over northeastern brazil region during the lgm

tvashtar awakening detected in april 2006 with osiris at the w m keck observatory abstract we detected a volcanic outburst in io s northern hemisphere on 17 april 2006 with the osiris imaging spectrometer at keck and confirmed it was still erupting on 2 june 2006 the eruption which we name 060417a was located in tvashtar paterae 100 km southeast of the february 2000 eruption the observed temperature was 1240 4 k over a surface area of 60 5 km 2 providing a total thermal output of 7 7 0 9 10 12 w

three decades of loki patera observations abstract we present observations of io s loki patera taken with the 10 m keck telescopes between 1998 and 2016 adding these data to those published by rathbun and spencer 2006 and the gemini data of de kleer and de pater 2016a 2017 results in a database of 3 5 3 8 m emission from loki patera over almost 3 decades data presented here contain adaptive optics ao observations of io s sunlit hemisphere at wavelengths between 1 6 and 5 m ao observations of io in eclipse at 2 5 m and non ao observations of io in eclipse at 1 6 12 m the non ao data were taken in september of 1999 during the early phase of a brightening event that was documented by howell et al 2001 dual component io flow model ifm fits to our 1999 observations show a mostly cool lava crust over almost the entire patera floor with a relatively small hotter component making up less than 1 of the total area consistent with previous observations the 30 year timeline of loki patera revealed that after an apparent cessation of or change in brightening events in 2002 loki patera became active again in 2009 the more recent activity may have a slightly shorter periodicity than observed by rathbun et al 2002 and the direction of flow propagation appears to have reversed since 2009 the flow direction is in the clockwise direction starting in the north or north east corner and propagating along the patera towards the south west during the galileo era the propagation was in the counter clockwise direction starting in the south west and propagating towards the east both the 30 year timeline and the 1 6 12 m spectrum that was obtained during the brightening event in 1999 agree well with matson et al s 2006 overturning lava lake model as modified by de kleer and de pater 2017

keck observations of eruptions on io in 2003 2005 abstract we report observations of four energetic volcanic eruptions on io at tupan patera on ut 8 march 2003 tung yo patera on ut 28 may 2004 sui jen patera on ut 30 may 2004 and south of babbar patera on ut 31 may 2005 the tung yo sui jen and south of babbar paterae eruptions are in locations where no activity had been seen before our observations were obtained at near infrared wavelengths 1 2 4 7 m with the 10 m keck telescope equipped with adaptive optics we report single and two temperature blackbody fits as well as single component and dual component io flow model ifm fits davies 1996 icarus 124 45 61 to all four eruptions where applicable we use 2 m and 5 m radiant fluxes the 2 5 m radiant flux ratio and radiant flux density of each thermal source to constrain the likely style of volcanic eruption all eruptions are characterized by a high temperature ifm component ranging from 1475 to 900 k from a relatively small area

infrared observations of io from juno abstract the jovian infrared auroral mapper jiram on board the nasa juno spacecraft is a dual band imager and spectrometer primarily designed to study the jovian atmosphere and aurorae in addition to its primary goal jiram has been used to obtain images and spectra of the galilean satellites jupiter s largest moons when the spacecraft attitude was favourable to achieve this goal here we present jiram s first images and spectra of io these observations are used to characterize the location and possible morphology and some temperatures of io s volcanic thermal sources the identification of so2 and the possible identification of other materials a new hot spot volcano is identified close to the south pole of io and others are seen in lower latitude regions which were previously unmapped images of the same region taken 2 months apart also show variations of hot spot intensity possibly due to new lava flows or to lava flow breakouts

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

the summer 1997 eruption at pillan patera on io implications for ultrabasic lava flow emplacement galileo data and numerical modeling were used to investigate the summer 1997 eruption at pillan patera on io this event now defined as pillanian eruption style keszthelyi et al this issue included a high temperature 1600 c possibly ultrabasic 140 km high plume eruption that deposited dark orthopyroxene rich pyroclastic material over 125 000 km2 followed by emplacement of dark flow like material over 3100 km2 to the north of the caldera we estimate that the high temperature energetic episode of this eruption had a duration of 52 167 days between may and september 1997 with peak eruption temperatures around june 28 1997 galileo 20 m pixel 1 images of part of the pillan flow field show a widespread rough pitted surface that is unlike any flow surface we have seen before we suggest that this surface may have resulted from 1 a fractured lava crust formed during rapid low viscosity lava surging perhaps including turbulent flow emplacement 2 disruption of the lava flow by explosive interaction with a volatile rich substrate or 3 a combination of 1 and 2 with or without accumulation of pyroclastic materials on the surface well developed flow lobes are observed suggesting that this is a relatively distal part of the flow field shadow measurements at flow margins indicate a thickness of 8 10 m we have modeled the emplacement of putative ultrabasic flows from the summer 1997 pillan eruption using constraints from new galileo data results suggest that either laminar sheet flows or turbulent channelized flows could have traveled 50 150 km on a flat unobstructed surface which is consistent with the estimated length of the pillan flow field 60 km our modeling suggests low thermal erosion rates 20 m erosion channels was unlikely especially distal to the source we calculate a volumetric flow rate of 2 7 103 m3 s 1 which is greater than those for typical mauna loa kilauea flows but comparable to those for the 1783 laki eruption and the inferred flow rates of the roza flows in the columbia river flood basalts the differences in ultrabasic eruption styles on earth and io appear to be controlled by the different eruption environments plumes at sites of ultrabasic eruptions on io suggest strong magma volatile interactions on a low gravity body lacking an atmosphere whereas the geology at sites of komatiite eruptions on earth suggest mostly submarine emplacement of thick flows with a pronounced lack of subaerial explosive activity