io hot spots in 1991 results from europa occultation photometry and infrared imaging abstract during the winter of 1991 an unusually favorable series of occultations of io by europa took place we obtained infrared photometry of four of these events at the united kingdom infrared telescope at wavelengths of 5 0 or 3 4 m in order to investigate the nature and distribution of volcanism on io by observing the occultation of the volcanic hot spots by the limb of europa observations at 3 4 m on 1991 01 08 detected a possible small hot spot in the northern hemisphere observations at 5 0 m on 1991 02 27 detected and resolved the major hot spot loki which had a diameter of 170 km and had three times its voyager 1 flux and also detected the voyager hot spot pele at about half its voyager 1 flux a 5 0 m occultation of pele on 1991 03 06 when loki was not occulted indicated no significant flux change since the week before infrared images of io obtained at the nasa infrared telescope facility between october 1990 and april 1991 show that the europa occultations occurred during a period of unusually high activity at loki loki showed very little thermal emission in observations between 1990 10 12 and 1990 11 27 but increased in flux by a factor of 10 in 32 days by 1991 12 29 loki then remained bright in all observations until 1991 03 26 but had begun to fade on 1991 04 09 such rapid variations in flux over such a large area are remarkable multiwavelength observations indicate that loki increased in temperature during the brightening and that materials hotter than 630 k were exposed at loki the possible pele type volcanoes surt and aten unlike pele were not detected with 3 8 m flux upper limits of about 8 gw m 1 str 1

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

magnetic susceptibility of soil an evaluation of conflicting theories using a national data set magnetic susceptibility values for topsoils across england arc combined with data for soil type geochemistry and concentrations of magnetotactic bacteria in order to evaluate different theories for explaining soil magnetism strongly magnetic soils in unpolluted areas are found over weakly magnetic substrates and are dominated by ultrafine superparamagnetic grains magnetotactic bacteria are present in insufficient concentrations to account for strongly magnetic soils and crop burning is discounted as a major factor a small number of samples show high values associated with either airborne magnetic particulates from pollution or residual primary ferrimagnetic minerals from igneous substrates the results are used to construct a new mechanism for the formation of secondary ferrimagnetic minerals that links abiological weathering and biological fermentation processes the fundamental driving force in the mechanism is fe supply which may be linked to climate observed causative associations between climate and the magnetic susceptibility of loess palaeosol sequences are supported by the findings

discovery of a powerful transient explosive thermal event at marduk fluctus io in galileo nims data analysis of galileo near infrared mapping spectrometer nims observations of marduk fluctus a volcano on the jovian moon io reveals a style of volcanic activity not previously seen there a powerful thermal event lasting only a few minutes in 1997 the thermal emission rapidly fades suggesting extremely rapid cooling of small clasts the duration and evolution of the explosive eruption is akin to what might be expected from a strombolian or vulcanian explosion the presence of such events provides an additional volcanic process that can be imaged by future missions with the intent of determining lava composition from eruption temperature an important constraint on the internal composition of io these data promise to be of particular use in understanding the mechanics of explosive volcanic processes on io

individual flood events detected in the recent sediments of the petit lac d annecy eastern france a 90 cm long freeze core from the petit lac d annecy was sampled at 1 cm intervals and studied using magnetic measurements chemical element and pollen analysis the results reveal four distinctive horizons in each of which the different lines of evidence point to deposition during a single major flood event the magnetic evidence shows that the sediment deposited in each event included a high proportion of surface soil derived material and this inference is consistent with the geochemical and pollen records from these layers no firm dates can be ascribed to these inwash events at present but a tentative chronology derived for the core from 210pb measurements varve counting where possible and correlation with a nearby previously dated core suggest that these flood events date from the late seventeenth to early nineteenth centuries a tentative correlation is suggested between the single event deposits and the record of summer autumn floods during the period

quantifying sediment supply at the end of the last glaciation dynamic reconstruction of an alpine debris flow fan in this paper we quantify the sediment dynamics in the formerly glaciated zielbach catchment in the italian alps from the end of the last glacial maximum lgm until today as a basis for our quantification we use the stratigraphic record offered by a 3 5 km2 large fan that we explore with a seismic survey stratigraphic analyses of drillhole material and 14c ages measured on organic matter encountered in these drillings in addition we calculate past denudation rate variability in the fan deposits using concentrations of cosmogenic 10be we merge this information into a scenario of how the sediment flux has changed through time and how this variability can be related to climatic variations framed within well known paraglacial models the results document a highly complex natural system from the lgm to the very early holocene ice melted discharge and climate variability promoted a high sediment flux sedimentation rate up to 40 mm yr this flux then dramatically decreased toward interglacial values 0 8 mm yr at 5 4 calibrated kyr b p however in contrast to the trend of classic paraglacial models the flux recorded at zielbach shows secondary peaks at 6 5 ka and 2 5 ka with values of 13 mm yr and 1 5 mm yr respectively paleo denudation rates also decrease from 33 mm yr at the beginning of the holocene to 0 42 mm yr at 5 ka with peaks of 6 mm yr and 1 1 mm yr at 6 5 ka and 2 5 ka high amplitude climate change is the most likely cause of the secondary peaks but anthropogenic activities may have contributed as well the good correlation between paleo sedimentation and paleo denudation rates suggests that the majority of the deglaciated material destocked from the zielbach catchment is stored in the alluvial fan

charting thermal emission variability at amirani with the galileo nims io thermal emission database nited abstract we have examined the variability of thermal emission from lava flows at amirani on io using measurements of radiant flux from detections by the galileo near infrared mapping spectrometer nims between 1996 and 2001 amirani is the longest currently active lava flow field in the solar system and a persistent thermal source in every galileo nims observation that covers its location we have quantified the thermal emission from hot spots correlated with discrete areas of new lava flow emplacement at points along the length of the amirani flow field in high spatial resolution nims observations in 2000 and 2001 where discernible the position of some effusive activity changes from orbit to orbit we find the implied style of emplacement of lava at amirani is consistent with pahoehoe like flows there is an estimated 50 decrease in discharge rate between 1997 and late 2001 perhaps linked to an outburst eruption in the amirani vicinity in february 2001 the variability of thermal emission from amirani is less than that seen at a number of other persistently active ionian volcanoes such as prometheus culann and loki patera all of these volcanoes exhibit large increases and decreases in the absolute magnitude of thermal emission see matson et al 2006 loki patera davies a g et al 2006 icarus 184 460 477 prometheus and davies a g ennis m e 2011 icarus 215 401 416 culann at amirani as at these volcanoes the thermal emission measured between 1996 and 2001 indicates a persistent although variable supply of magma to the surface in high spatial resolution nims observations of hot spots obtained in 2000 and 2001 we estimate the emitted power from active lava flows associated with amirani to be 170 30 gw which corresponds to total effusion rates assuming a basaltic composition from multiple points along the amirani flow of 34 56 m 3 s

new estimates for io eruption temperatures implications for the interior abstract the initial interpretation of galileo data from jupiter s moon io suggested eruption temperatures 1600 c tidal heating models have difficulties explaining io s prodigious heat flow if the mantle is 1300 c although we suggest that temperatures up to 1450 c may be possible in general io eruption temperatures have been overestimated because the incorrect thermal model has been applied much of the thermal emission from high temperature hot spots comes from lava fountains but lava flow models were utilized we apply a new lava fountain model to the highest reported eruption temperature the ssi observation of the 1997 eruption at pillan this resets the lower temperature limit for the eruption from 1600 to 1340 c additionally viscous heating of the magma may have increased eruption temperature by 50 100 c as a result of the strong compressive stresses in the ionian lithosphere while further work is needed it appears that the discrepancy between observations and interior models is largely resolved

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

detecting climatic signals in an anthropogenically disturbed catchment the late holocene record from the petit lac d annecy french alps historical and documentary records from the petit lac d annecy indicate that human activities have been the dominant geomorphic process shaping the catchment during the late holocene with deforestation agriculture and artificial drainage profoundly affecting both the pace and spatial distribution of soil erosion the impact of past climatic change on the evolution of the catchment is less certain because of the lack of long term climate records for the site previous attempts to use the sediment record from the lake to investigate the role past climate change may have played were hampered by the difficulty in isolating and disentangling the climatic signal preserved within the archive because of overprinting of human activity this is a common problem in regions with a long history of human activity in the landscape in this study we use a range of novel statistical techniques including cross correlation and cross spectral analysis to assess the relative importance of climate in driving landscape dynamics the statistical analysis is carried out on an updated high resolution palaeo environmental data set from the petit lac d annecy the results of the statistical analysis indicate that regional climate phenomena such as the atlantic multidecadal oscillation are partly responsible for landscape dynamics at petit lac d annecy throughout the late holocene we find that the petit lac d annecy catchment typically requires decades or longer to respond to changes in precipitation reflecting the stochastic nature of river sediment storage and transport the use of a 4 yr integrated lake core record effectively attenuates the signal shredding effect of shorter term internally generated sediment transport processes nonetheless the lake record of climatically induced geormorphic process responses is weak compared with the pervasive impact of human activities

lava lakes on io observations of io s volcanic activity from galileo nims during the 2001 fly bys abstract galileo s near infrared mapping spectrometer nims obtained its final observations of io during the spacecraft s fly bys in august i31 and october 2001 i32 we present a summary of the observations and results from these last two fly bys focusing on the distribution of thermal emission from io s many volcanic regions that give insights into the eruption styles of individual hot spots we include a compilation of hot spot data obtained from galileo voyager and ground based observations at least 152 active volcanic centers are now known on io 104 of which were discovered or confirmed by galileo observations including 23 from the i31 and i32 io fly by observations presented here we modify the classification scheme of keszthelyi et al 2001 j geophys res 106 e12 33 025 33 052 of io eruption styles to include three primary types promethean lava flow fields emplaced as compound pahoehoe flows with small plumes 200 km high plumes and rapidly emplaced flow fields and a new style we call lokian that includes all eruptions confined within paterae with or without associated plume eruptions thermal maps of active paterae from nims data reveal hot edges that are characteristic of lava lakes comparisons with terrestrial analogs show that io s lava lakes have thermal properties consistent with relatively inactive lava lakes the majority of activity on io based on locations and longevity of hot spots appears to be of this third type this finding has implications for how io is being resurfaced as our results imply that eruptions of lava are predominantly confined within paterae thus making it unlikely that resurfacing is done primarily by extensive lava flows our conclusion is consistent with the findings of geissler et al 2004 icarus this issue that plume eruptions and deposits rather than the eruption of copious amounts of effusive lavas are responsible for io s high resurfacing rates the origin and longevity of islands within ionian lava lakes remains enigmatic

temperature and area constraints of the south volund volcano on io from the nims and ssi instruments during the galileo g1 orbit analysis of data from darkside and eclipse observations of io by the nims and ssi instruments show that the south volund hot spot is a manifestation of high temperature active silicate volcanism the nims data are fitted with a two temperature model developed from modelling terrestrial lavas which yields a better fit to the data than a single temperature fit the multispectral color temperatures obtained from nims are compared with the brightness temperatures obtained from the ssi instrument and show excellent agreement for the hotter of the two components fitted to the nims data the two components might correspond to a cooled crust which has formed on the surface of an active flow or lava lake at a temperature of approximately 450 k and covering an area of about 50 km and a hotter and much smaller component at a temperature of approximately 1100 k and an area of less than 0 1 km the hot component implies the existence of cracks in the surface crust of a flow or lake through which the hot interior radiates a hot vent area or breakouts of lava forming new flow lobes the ratio of these areas is consistent with the crack to crust ratio of some lava flows and lava lakes on earth

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

hot spots on io initial results from galileo s near infrared mapping spectrometer the near infrared mapping spectrometer on galileo has monitored the volcanic activity on io since june 28 1996 this paper presents preliminary analysis of nims thermal data for the first four orbits of the galileo mission nims has detected 18 new hot spots and 12 others which were previously known to be active the distribution of the hot spots on io s surface may not be random as hot spots surround the two bright so2 rich regions of bosphorus regio and colchis regio most hot spots seem to be persistently active from orbit to orbit and 10 of those detected were active in 1979 during the voyager encounters we report the distribution of hot spot temperatures and find that they are consistent with silicate volcanism

volcanic hot spots on io correlation with low albedo calderas comparison of voyager imaging data with voyager 1 infrared observations iris and with ground based telescopic infrared data demonstrates a strong correlation between hot spots and low albedo features reflectivity 0 3 in all visual wavelengths on io most of these low albedo areas occur on the floors of volcanic calderas and many are associated with active or recent volcanism we use this correlation to identify additional hot spots in regions not observed by iris and to model their temperatures the major features discovered by this method are in a ringlike structure in the south polar region centered at 140 w 75 s and amaterasu patera 307 w 38 n our model temperature for the south polar feature is 280 50 k taking account of the high latitudes of these features the estimated global average heat flow from the hot spots becomes 1 8 0 5 w m 2 most of this heat emanates from just a few very large hot spots the global distribution of hot spots is further evidence that io is a dimorphous body the hemisphere centered on 310 w 30 s is much more volcanically active than the opposite hemisphere the styles of heat transfer in io conductive versus convective may be related to the global distribution of hot spots large eruptive plumes and large scale topographic relief the correlation between hot spots and dark areas is due to 1 the absence of the bright materials such as so2 frost which cover most of the surface and 2 the presence of a low albedo substance spectral properties of the low albedo features extracted from the voyager multispectral data are consistent with a number of candidate materials liquid sulfur boiled sulfur silicate sulfur mixtures zinc sulfide fe sulfate and fe chloride quenched sulfur allotropes on the other hand are redder than the low albedo features on io and are incompatible with the elevated temperatures of the hot spots some of the dark caldera floor materials may be liquid sulfur and or thermally altered boiled sulfur liquid sulfur would tend to collect in the topographic depressions and fractured bedrock of the calderas and this would explain the concentration of low albedo material in the calderas the presence of liquid sulfur is also suggested by the hot spot temperature distribution typically 200 400 k and by morphologies suggestive of lava lakes however the liquid boiled sulfur model does not seem to work for babbar and amaterasu paterae and the evidence for liquid sulfur is not conclusive

a 4000 year record of hydrologic variability from the olympic mountains washington usa sedimentological and geochemical analyses of gravity and piston cores retrieved from lake quinault washington reveal an 4000 year flood dominated depositional record individual flood event laye

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

silicate cooling model fits to galileo nims data of volcanism on io abstract the near infrared mapping spectrometer nims has obtained spectra of volcanoes on the surface of the jovian satellite io fits to data using a silicate cooling model allow us to constrain lava eruption rates and eruption age the thermal signatures of the hot spots are indicative of active and cooling silicate lava flows for large active hot spots maximum ages of flow surfaces detected by nims typically range from days to months although in one case it is nearly 30 years mass eruption rates for the main hot spots are in the range 7 m3 s 1 to 79 m3 s 1 using an average flow thickness of 1 m these mass eruption rates are orders of magnitude less than those implied for large thermal outbursts on io the eruptions observed during june 1996 are most likely of a different eruption style on a much smaller scale the observation analyzed here may be representative of the current background level of volcanic activity on the anti jove hemisphere of io the global mass eruption rate from these non outburst hot spots is calculated to be 43 km3 year equivalent to a global resurfacing rate of about 1 mm year about 10 of the minimum required global resurfacing volume the total observed energy output from the 14 hot spots analyzed is 3 6 1012 w normalized globally these hot spots contribute approximately 10 of io s radiometric heat flux

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

volcanic origin of the eruptive plumes on io a quadruple long exposure of io in eclipse exhibits faint auroral emission from the eruptive plumes no luminous spots in the vents predicted by gold were observed heat from the interior of io appears to be the predominant source of energy in the plumes

geochronological position of badlands and geomorphological patterns in the guadix baza basin se spain abstract the guadix baza basin is one of a number of intramontane depressions located within the betic cordillera se spain where the geological and geomorphological evolution is controlled by tectonic activity the basin ceased to be closed after capture by the atlantic network when five main land systems developed late pleistocene geological evolution basically consisted of erosional modelling when badlands were deeply incised in highly erodible materials marls and silts three travertine platforms and several palaeolithic sites were used to determine that this main incision period fell within a 115 000 48 000 yr range there are few signs of geomorphological evolution of this basin in the last 48 000 yr based on these geomorphological data and soil development tectonic uplift of the basin probably played a secondary role in its evolution and climatic conditions in southern iberia in the 144 000 48 000 yr period were more humid and variable than later

the recent history of hydro geomorphological processes in the upper hangbu river system anhui province china abstract this paper describes 20th century climate and human impacts on terrestrial and fluvial systems in the dabie mountains anhui province china based on analyses of four types of information analyses of particle size mineral magnetism organic carbon nitrogen and phosphorus in a sediment core taken from the longhekou reservoir built in 1958 ad in the upper reaches of hangbu river provide an 45 year record of fluvial responses while monitored meteorological and hydrological data provide records of climate and river discharge census data compiled for the local shucheng county provide records of population and land use complemented with analyses of satellite images the xiaotian river delivers over 65 of the total water and silt to the reservoir analyses indicate that the fluvial regime tracks the monsoon climate over seasonal timescales but human activities have a strongly mediating effect on sediment supply sediment delivery and to a lesser extent runoff over longer timescales notable periods of human impact on erosion include the great leap forward 1958 1960 and great cultural revolution 1966 1976 a rising trend in precipitation and new land use changes at the present time may be leading to an enhanced flood risk

io loki patera as a magma sea 1 we develop a physical model for loki patera as a magma sea we calculate the total volume of magma moving through the loki patera volcanic system every resurfacing cycle 540 days and the resulting variation in thermal emission the rate of magma solidification at times reaches 3 106 kg s 1 with a total solidified volume averaging 100 km3 yr 1 a simulation of gas physical chemistry evolution yields the crust porosity profile and the timescale when it will become dense enough to founder in a manner consistent with observations the loki patera surface temperature distribution shows that different areas are at different life cycle stages on a regional scale however there can be coordinated activity indicated by the wave of thermal change which progresses from loki patera s sw quadrant toward the ne at a rate of 1 km d 1 using the observed surface temperature distribution we test several mechanisms for resurfacing loki patera finding that resurfacing with lava flows is not realistic only the crustal foundering process is consistent with observations these tests also discovered that sinking crust has a heat deficit which promotes the solidification of additional magma onto the sinking plate bulking up in the limiting case the mass of sinking material can increase to a mass of 3 times that of the foundering plate with all this solid matter sinking there is a compensating upward motion in the liquid magma this can be in excess of 2 m yr 1 in this manner solid liquid convection is occurring in the sea

catchment hydro geomorphological responses to environmental change in the southern uplands of scotland lake sediment and geomorphic evidence from the loch of the lowes st mary s loch basin in the central southern uplands of scotland provide a multiproxy reconstruction of changing sediment availability and transmission through the catchment interrogation of magnetic geochemical and grain size parameters for lake and catchment materials suggests it is possible to identify independent proxies that reflect both supply availability and discharge capacity controls on the sediment signal chronological control for the lake sediment record is proposed by linking a 210pb 137cs chronology for the last c 120 yr to an age depth profile based on proposed temporal correlations between cyclic hirm lf variability and the north atlantic oscillation geochronological studies on debris cones and alluvial fans yield evidence for episodic hillslope gullying 2000 0 bc with more extensive region wide slope instability ad 700 900 1100 1300 and after ad 1450 1550 and gully stabilization over the last 150 years the latter two episodes coincide with the lake sediment evidence for increased sediment supply from ad 1600 declining after ad 1870 the capacity related lake proxies appear to identify phases of increased flooding ad 1625 1650 1680 1700 1730 1760 1800 1815 1850 1880 1910 1930 1960 1970 and possibly the 1990s close correspondence between the sediment flood archive and historical records of flooding in scotland suggests that lake catchment systems of this type have the potential to yield valuable information on past hydrological response

meteorological and land use controls on past and present hydro geomorphic processes in the pre alpine environment an integrated lake catchment study at the petit lac d annecy france a wide range of environmental records is integrated in order to reconstruct the mechanisms of flooding and sediment transport within the 170 km2 petit lac catchment annecy france over time scales of 10 1 to 102 years these records include sequential lake sediment trap samples and cores floodplain stratigraphies dated landform assemblages hydro meteorological records and documented histories of river channel and land use change mineral magnetic measurements are used as the basis for classifying catchment sediment sources and tracing sediment movements through time records of magnetic susceptibility for monthly sediment trap samples 1998 99 track seasonal discharge peaking in winter and spring magnetic records in lake sediment cores are compared against and tuned to precipitation records to provide dated proxy records for past discharge spanning sub annual to decadal time scales back to 1826 calculated sediment accumulation rates in lake sediment cores are used as proxies for time averaged catchment sediment load analysis of the results reveals that climate and land use controls on the hydrological and sediment system are complex and vary according to the time scale of observation in general cycles of agricultural expansion and deforestation appear to have been the major cause of shifts in the sediment system through the late holocene deforestation in the 18th century may have caused a number of high magnitude flood and erosion events as the time scale of observation becomes shorter changes in climate and hydro meteorological conditions become progressively more important since the mid 19th century smoothed records of discharge roughly follow annual precipitation this is in contrast to sediment load which follows the trend of declining land use pressures episodic erosion events during this recent period seem to be linked to geomorphic evidence for slope instability in the montane and sub alpine zones triggered by intense summer rainfall at the annual scale changes in seasonal rainfall become paramount in determining sediment movement to downstream locations the study demonstrates that the connections between forcings and responses span a four dimensional array of temporal and spatial scales with strong evidence for dominantly nonlinear forcing response mechanisms

testing a cellular modelling approach to simulating late holocene sediment and water transfer from catchment to lake in the french alps since 1826 this paper describes the application of a hydrogeomorphological numerical model caesar to simulate at hourly time steps changes in the hydrological and sediment regime of the petit lac d annecy catch ment the outputs of the model were validated in three ways in the short term 5 years water discharge out puts were compared against observed instrumental data over the longer term modelled sediment discharge ad 1825 2005 was compared with proxies for detrital sediment influx environmental magnetism and accumu lation rates discerned from a 210 pb chronology for the lake sediments finally spatial validation of the modelled erosion and deposition of sediment was undertaken by comparison with a field and remotely sensed survey of catchment geomorphology the results suggest that while minor perturbations in forest cover during the last 180 years have partially conditioned the response of the sediment system the bulk of modelled sediment discharge and particularly the peaks in sediment discharge were controlled by flood duration and magnitude which in turn is driven by precipitation storms floods and snowmelt basin geometry and geomorphology of each sub catchment ire and tamie were also important in producing differences in the modelled sediment discharge in essence these differences were a function of sediment accommodation space and the ability of each system to store and release sediments modelled sediment discharge and para lake sediments display similar histories and thus are both interpreted as reflecting variations in detrital sediment supply intriguingly the style of mod elled sediment discharge from the ire a confined mountain torrent displays a greater similarity to and perhaps dominates the lake sediment record these results provide partial validation of the caesar model and indi cate that perhaps in the future it may be used as an exploratory and predictive tool in determining the impact of changes in climate meteorology and land use on lake catchment systems

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

the record of land use change and soil erosion in the late holocene sediments of the petit lac d annecy eastern france pollen chemical and magnetic analysis of a 6 m core from the petit lac d annecy provides a record of land use change and soil erosion spanning the last 2000 years variations in the magnetic properties of the sediments especially above 3 m in the core can be linked to the history of soil inwash over the last 1000 years these changes together with parallel ones in element concentrations and pollen frequencies both concentrations and percentages can be interpreted by reference to the land use history in the catchment during medieval and post medieval times peak deforestation and human impact on vegetation and soils is recorded from the eleventh to fourteenth centuries and again during the eighteenth century the present study suggests that future detailed analyses of the laminated sediments of the lake could provide a precisely datable fine resolution environmental history of the lake and its drainage basin

volcanic resurfacing of io post repair hst imaging abstract in march 1994 we used the newly refurbished hubble space telescope hst to obtain global imaging of io at five wavelengths between 0 34 and 1 02 m with a spatial resolution of 160 km the images provided the clearest view of io since voyager and the first systematic observations in the wavelength range 0 7 1 0 m we have produced absolutely calibrated global mosaics of io s reflectance in all our five wavelengths the near infrared images reveal that the 0 55 to 0 7 m absorption edge seen in io s disk integrated spectrum has a very different spatial distribution from the better known 0 40 to 0 50 m absorption edge studied by voyager and must be generated by a different chemical species the 0 55 to 0 7 m absorption edge is strongly concentrated in the pyroclastic ejecta blanket of the volcano pele at a few much smaller discrete spots and probably also in the polar regions the pele ejecta spectrum is consistent with the idea that s 2 o partially decomposed to s 4 and probably s 3 may be the species responsible for the 0 55 to 0 7 m absorption edge at pele and elsewhere on io though s 4 generated by other processes may also be a possibility s 2 o can be produced by high temperature decomposition of so 2 gas and the high temperature of the pele volcano may account for its concentration there spectral anomalies of comparable size and prominence are not seen around the other pele type volcanos surt and aten a s mcewen and l a soderblom 1983 icarus 55 191 217 suggesting that these volcanos if chemically similar to pele are much less active the spectrum of high latitude regions is similar to that of quenched red sulfur glass and if this similarity is not coincidental the glass may be preserved here by the low polar surface temperatures alternatively the low polar temperatures may preserve sulfur that has been reddened by radiation there are many changes in albedo patterns in the 15 years between voyager and these hst observations but these are generally subtle at hst resolution and are not strongly concentrated in longitude however there was a major brightening of a 400 km diameter region centered on ra patera between march 1994 and repeat hst observations in july 1995 which was a larger albedo change than any seen in the previous 15 years this was presumably due to a large eruption at ra patera as confirmed by galileo images long exposure eclipse images of io at 1 02 m on march 6 1994 place strong limits on the area of exposed silicate magma on io at the time of the observations

a komatiite analog to potential ultramafic materials on io ultramafic volcanism is one model which fits currently available data for some eruptions on jupiter s moon io assuming that such activity does occur it is possible to apply komatiitic analogs and terrestrial ultramafic flow models to io we have used such analogs and models along with galileo data to investigate the nature of ultramafic materials that are assumed to occur at high temperature hotspots on io the unusual komatiites of the commondale greenstone belt south africa are consistent with available galileo data on the temperatures and composition of potential ionian ultramafic materials these komatiites had high sio2 50 wt and mgo 31 wt contents which are inferred to result in high liquidus temperatures 1610 c low dynamic viscosities 0 2 pa s and low densities 2680 kg m and in the crystallization of orthopyroxene phenocrysts not found in other komatiites we used the commondale composition and the model of williams et al 1998 to investigate potential ultramafic flow behavior on io compared to their terrestrial counterparts ionian ultramafic lava flows would have less potential for turbulent flow lower maximum emplacement distances and lower thermal erosion rates because of the lower ionian gravity and their more silicic composition shallow 10 m thermal erosion channels seem less likely on io unless 1 lavas are superheated 2 lavas are more ultramafic 31 mgo 3 eruption rates eruption durations or flow volumes are high or 4 substrates are unconsolidated partly consolidated or volatile rich and thus more erodable if volatiles are present in the lava as vesicles then increasing lava vesicularity results in decreasing maximum emplacement distances decreasing thermal erosion rates and decreasing erosion channel depths for given eruption durations

high temperature hot spots on io as seen by the galileo solid state imaging ssi experiment high temperature hot spots on io have been imaged at 50 km spatial resolution by galileo s ccd imaging system ssi images were acquired during eclipses io in jupiter s shadow via the ssi clear filter 0 4 1 0 m detecting emissions from both small intense hot spots and diffuse extended glows associated with io s atmosphere and plumes a total of 13 hot spots have been detected over 70 of io s surface each hot spot falls precisely on a low albedo feature corresponding to a caldera floor and or lava flow the hot spot temperatures must exceed 700 k for detection by ssi observations at wavelengths longer than those available to ssi require that most of these hot spots actually have significantly higher temperatures 1000 k or higher and cover small areas the high temperature hot spots probably mark the locations of active silicate volcanism supporting suggestions that the eruption and near surface movement of silicate magma drives the heat flow and volcanic activity of io

discovery of hotspots on io using disk resolved infrared imaging active tidally driven volcanism on jupiter s satellite io1 2 was discovered in voyager images in 1979 voyager also detected the thermal emission from the volcanoes3 4 and this emission has since been monitored from earth using a variety of techniques employing single element infrared detectors5 10 because of io s small angular size no more than 1 2 arcsec however it has normally been possible to resolve and locate only the brightest individual hotspot loki although additional hotspots can be located at five year intervals during occultations of io by the other galilean satellites11 12 here we present first results using two new techniques for ground based observation of io s hotspots first use of an infrared array camera allowed us to exploit the mauna kea observatory s excellent atmospheric stability to obtain direct infrared images of io with resolution better than 0 5 arcsec this allowed us to see more than one hotspot on io in jupiter eclipse in jupiter s shadow second we used the camera to make the first observations of the jupiter occultation disappearance behind jupiter of the hotspots these new techniques have revealed and located at least three hotspots and will now permit routine ground based monitoring of the locations temperatures and sizes of multiple hotspots on io

galileo s first images of jupiter and the galilean satellites the first images of jupiter io europa and ganymede from the galileo spacecraft reveal new information about jupiter s great red spot grs and the surfaces of the galilean satellites features similar to clusters of thunderstorms were found in the grs nearby wave structures suggest that the grs may be a shallow atmospheric feature changes in surface color and plume distribution indicate differences in resurfacing processes near hot spots on io patchy emissions were seen while io was in eclipse by jupiter the outer margins of prominent linear markings triple bands on europa are diffuse suggesting that material has been vented from fractures numerous small circular craters indicate localized areas of relatively old surface pervasive brittle deformation of an ice layer appears to have formed grooves on ganymede dark terrain unexpectedly shows distinctive albedo variations to the limit of resolution

a model for large scale volcanic plumes on io implications for eruption rates and interactions between magmas and near surface volatiles 1 volcanic plumes deposit magmatic pyroclasts and so2 frost on the surface of io we model the plume activity detected by galileo at the pillan and pele sites from 1996 to 1997 assuming that magmatic eruptions incorporate liquid so2 from near surface aquifers intersecting the conduit system and that the so2 eventually forms a solid condensate on the ground the temperature and pressure at which deposition of solid so2 commences in the ionian environment and the radial distance from the volcanic vent at which this process appears to occur on the surface are used together with observed vertical heights of plumes to constrain eruption conditions the temperature pressure and density of the gas magma mixtures are related to distance from the vent using continuity and conservation of energy similar eruption mass fluxes of order 5 107 kg s 1 are found for both the pillan and the pele plumes the pele plume requires a larger amount of incorporated so2 29 34 mass than the pillan plume up to 6 mass implied vent diameters range from 90 m at pillan to 500 m at pele the radial extents of the optically dense isothermal incandescent parts of the eruption plumes immediately above the vents are 100 m at pillan and 1300 m at pele gas pressures in the vents are 20 kpa at pillan and 2 kpa at pele and the eruption conditions appear to be supersonic in both cases though only just so at pele

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

io heat flow from small volcanic features abstract we identify nine new faint thermal sources on io via color ratio images constructed from relatively high spatial resolution galileo nims data acquired late in the mission all of these identifications are associated with small dark paterae we utilize nims data to quantify their volcanic thermal emission as 0 53 1012 w or 0 5 of io s total heat flow in addition we refine our previous estimates of the thermal emission from 47 hot spots and highlight several hot spots within the amirani flow field small dark paterae still out number faint close to the limit of detection hot spots identified in high spatial resolution multi wavelength nims data in particular we point out 24 small dark paterae that were scanned by nims at resolutions down to 17 km pixel but had no detectable volcanic thermal emission all dark paterae are expected to have some volcanic thermal emission but the small size and finite number of detectable faint sources limit their contribution to the total heat flow on io compared to small paterae small dark flows are more numerous but must have significantly lower surface temperatures finally we update and summarize our results for the global heat flow on io due to 242 recently active volcanic features including other dark paterae as well as large dark flows the volcanic thermal emission from known hot spots undetected scanned dark patera and outbursts can account for only 56 2 1012 w or 54 of io s total heat flow approximately 49 1012 w or 46 of io s heat flow remains an enigma

flood stratigraphies in lake sediments a review abstract records of the frequency and magnitude of floods are needed on centennial or millennial timescales to place increases in their occurrence and intensity into a longer term context than is available from gauged river flow and historical records recent research has highlighted the potential for lake sediment sequences to act as a relatively untapped archive of high magnitude floods over these longer timescales abyssal lake sediments can record past floods in the form of coarser grained laminations that reflect the capacity for river flows with greater hydrodynamic energy to transport larger particles into the lake this paper presents a framework for investigating flood stratigraphies in lakes by reviewing the conditioning mechanisms in the lake and catchment outlining the key analytical techniques used to recover flood records and highlighting the importance of appropriate field site and methodology selection the processes of sediment movement from watershed to lake bed are complex meaning relationships between measureable sedimentary characteristics and associated river discharge are not always clear stratigraphical palaeoflood records are all affected to some degree by catchment conditioning fluvial connectivity sequencing of high flows delta dynamics as well as within lake processes including river plume dispersal sediment focussing re suspension and trapping efficiency with regard to analytical techniques the potential for direct e g laser granulometry and indirect e g geochemical elemental ratios measurements of particle size to reflect variations in river discharge is confirmed we recommend care when interpreting fine resolution geochemical data acquired via micro scale x ray fluorescence xrf core scanning due to variable down core water and organic matter content altering x ray attenuation we also recommend accounting for changes in sediment supply through time as new or differing sources of sediment release may affect the hydrodynamic relationship between particle size and or geochemistry with stream power where these processes are considered and suitable dating control is obtained discrete historical floods can be identified and characterised using palaeolimnological evidence we outline a protocol for selecting suitable lakes and coring sites that integrates environmental setting sediment transfer processes and depositional mechanisms to act as a rapid reference for future research into lacustrine palaeoflood records we also present an interpretational protocol illustrating the analytical techniques available to palaeoflood researchers to demonstrate their utility we review five case studies of palaeoflood reconstructions from lakes in geographically varied regions these show how lakes of different sizes and geomorphological contexts can produce comprehensive palaeoflood records these were achieved by consistently applying site validated direct and proxy grain size measurements well established chronologies validation of the proxy process interpretation and calibration of the palaeoflood record against instrumental or historical records

violent silicate volcanism on io in 1996 we monitored io s volcanic thermal emission from 1 7 to 4 8 m in 1995 96 the data reveal a number of brightenings when io s thermal emission increased several fold we use a model of emission from lava flows to understand observations of two brightenings in 1996 the brightenings were caused by eruptions 3km in extent with eruptive rates of 104 106 m s 1 and with maximum lava temperatures 1400 k these events were probably lava lakes and or fire fountains

the nature of the volcanic activity at loki insights from galileo nims and ppr data abstract loki is the largest patera and the most energetic hotspot on jupiter s moon io in turn the most volcanically active body in the solar system but the nature of the activity remains enigmatic we present detailed analysis of galileo near infrared mapping spectrometer nims and photopolarimeter radiometer ppr observations covering the 1 5 100 m wavelength range during the i24 i27 and i32 flybys the general pattern of activity during these flybys is consistent with previously proposed models of a resurfacing wave periodically crossing a silicate lava lake in particular our analysis of the i32 nims observations shows over much of the observed patera surface temperatures and implied ages closely matching those expected for a wave advancing counterclockwise at 0 94 1 38 km day the age pattern is different than other published analyses which do not show as clearly this azimuthal pattern our analysis also shows two additional distinctly different patera surfaces the first is located along the inner and outer margins where components with a 3 00 4 70 m color temperature of 425 k exist the second is located at the southwestern margin where components with a 550 k color temperature exist although the high temperatures could be caused by disruption of a lava lake crust some additional mechanism is required to explain why the southwest margin is different from the inner or outer ones finally analysis of the temperature profiles across the patera reveal a smoothness that is difficult to explain by simple lava cooling models paradoxically at a subpixel level wide temperature distributions exist which may be difficult to explain by just the presence of hot cracks in the lava crust the resurfacing wave and lava cooling models explain well the overall characteristics of the observations however additional physical processes perhaps involving heat transport by volatiles are needed to explain the more subtle features

silicate volcanism on io io is currently emitting 1 1 5 w m 2 of tidal energy as a result of its volcanic activity if the lithosphere is more than 20 km thick as appears probable from the surface relief only a fraction of the tidal energy can be dissipated within the lithosphere otherwise it will become thinner the rest of the tidal energy must be dissipated below the lithosphere io is likely to be highly differentiated as a result of the volcanic activity with a low melting temperature fraction such as basalt near the surface and a high melting temperature fraction such as peridotite at depth if solidus temperatures are reached at depths shallower than the thickness of the basalt layer a partial melt zone will separate an all basalt lithosphere above from a peridotite mantle below and part of the tidal energy will be dissipated by viscous deformation within the melt zone most of the energy dissipated below the lithosphere will be transported upward through the lithosphere as silicate magma which is generated in quantities sufficient to resurface the satellite at a rate of a few tenths of a centimeter a year depending on the lithosphere thickness many of the characteristics of the ionian surface have been explained in terms of sulfur volcanism however most of the features observed can be as readily explained by silicate volcanism and silicates are more consistent with the apparent strength of the surface as implied by the relief simulations of basaltic eruptions indicate that the surface temperatures that would result from basaltic eruptions are similar to those measured by the voyager infrared interferometer spectrometer experiment the high rates of emission by the ionian hot spots imply eruption rates that are high compared with typical terrestrial eruptions an eruption rate of 4000 m3 s 1 may be required to explain loki which is currently emitting 1013 w although the near surface materials are mainly silicate they may contain several percent of volatile components rich in s na and k remobilization of these components by the ongoing silicate eruptions causes the plumes provides material to the torus and gives the satellite its characteristic reflectivity

hillslope gullying in the solway firth morecambe bay region great britain responses to human impact and or climatic deterioration abstract in the solway firth morecambe bay region of great britain there is evidence for heightened hillslope instability during the late holocene after 3000 cal bp little or no hillslope geomorphic activity has been identified occurring during the early holocene but there is abundant evidence for late holocene hillslope erosion gullying and associated alluvial fan and valley floor deposition interpretation of the regional radiocarbon chronology available from organic matter buried beneath alluvial fan units suggests much of this geomorphic activity can be attributed to four phases of more extensive gullying identified after 2500 2200 1300 1000 1000 800 and 500 cal bp both climate and human impact models can be evoked to explain the crossing of geomorphic thresholds and palaeoecological data on climatic change bog surface wetness and human impact pollen together with archaeological and documentary evidence of landscape history provide a context for addressing the causes of late holocene geomorphic instability high magnitude storm events are the primary agent responsible for gully incision but neither such events nor cooler wetter climatic episodes appear to have produced gully systems in the region before 3000 cal bp increased gullying after 2500 2200 cal bp coincides with population expansion during iron age and romano british times the widespread and extensive gullying after 1300 1000 cal bp and after 1000 800 cal bp coincides with periods of population expansion and a growing rural economy identified during norse times 9 10th centuries ad and during the medieval period 12 13th centuries ad these periods were separated by a downturn associated with the harrying of the north ad 1069 to 1070 the gullying episode after 500 cal bp also coincides with increased anthropogenic pressure on the uplands with population growth and agricultural expansion after ad 1500 following 150 years of malaise caused by livestock and human the black death plagues poor harvests and conflicts on the scottish english border the increased susceptibility to erosion of gullies is a response to increased anthropogenic pressure on upland hillslopes during the late holocene and the role of this pressure appears crucial in priming hillslopes before subsequent major storm events in particular the cycles of expansion and contraction in both population and agriculture appear to have affected the susceptibility of the upland landscape to erosion and the hillslope gullying record in the region therefore contributes to understanding of the timing and spatial pattern of human exploitation of the upland landscape

evidence for changes in holocene sediment flux in semer water and raydale north yorkshire uk article i nfo we present preliminary results from studies carried out in the lake and extensively gullied drainage basin of semer water in north yorkshire england the results obtained so far are limited by physical problems encountered during coring at the present day lake the complex nature of the sedimentary infill upstream in raydale and difficulties experienced in establishing a continuous holocene chronology for the site both magnetic measurements and organic geochemical analyses show that the bulk of the sediment sampled in semer water and in the alluvial area of raydale just upstream is derived from the catchment although in some cases the allochthonous magnetic signature is overprinted by contributions from bacterial magnetosomes growing in the lake or surface sediments significant traces of polyaromatic hydrocarbons pahs in sediments contemporary with the mesolithic occupation of the pennines reinforce evidence from elsewhere for the use of fire at this time several lines of evidence identify a mid holocene period of reduced allochthonous input rapid sediment accumulation during the period between 4200 and 3500 cal bp points to the likelihood of increased erosion during the bronze age geomorphological studies point to periods of alternating dissection and aggradation in the catchment during the last 2000 years the record presented gives some indication of the potential for uniting geomorphological palaeolimnological and organic geochemical research in an effort to trace the holocene evolution of a complex highly eroded system 2008 elsevier b v all rights reserved

land use changes and longer term human environment interactions in a mountain region sudetes mountains poland abstract long term socio economic changes in the mountain communities best documented as land use changes have been reflected in alternating functioning of the environmental system in the upper valleys in the sudetes mountains the main role that human activity played on morphogenetic processes was to intensify or to weaken the linkages between hillslope and river systems all stages of environmental change as a result of increasing or decreasing human impact are easily recognisable in the area both as human made landforms and as sediment records therefore they provide archives of past and present human activities allowing for the reconstruction of morphogenetic processes in the past detailed sedimentological and geomorphological analyses along with studies on archival documents topographic maps and aerial photographs from various periods reveal many local variations even within one small drainage basin occasionally human impact might be of the same type and intensity in the entire catchment but coeval environmental records for example the thickness of colluvial or alluvial sediments may differ substantially the role of local topography hillslope and valley length hillslope gradient and microrelief etc considerably influences sediment transfer and depositional processes hillslope channel coupling is of importance as only in some places transport and sediment export from the catchment was favoured in other places local topographic conditions favoured sediment storage limiting transport distance human impact turned out to be more important and much more widespread than previously assumed despite fewer human induced sediments in the upper valley reaches these are actually better archives for reconstructing the linkages between land use changes and hillslope and channel response small size catchments in the upstream parts of the study area are therefore suitable areas for reconstructing assessing and quantifying past morphological human environment interactions

the zamama thor region of io insights from a synthesis of mapping topography and galileo spacecraft data abstract we have studied data from the galileo spacecraft s three remote sensing instruments solid state imager ssi near infrared mapping spectrometer nims and photopolarimeter radiometer ppr covering the zamama thor region of io s antijovian hemisphere and produced a geomorphological map of this region this is the third of three regional maps we are producing from the galileo spacecraft data our goal is to assess the variety of volcanic and tectonic materials and their interrelationships on io using planetary mapping techniques supplemented with all available galileo remote sensing data based on the galileo data analysis and our mapping we have determined that the most recent geologic activity in the zamama thor region has been dominated by two sites of large scale volcanic surface changes the zamama eruptive center is a site of both explosive and effusive eruptions which emanate from two relatively steep edifices zamama tholi a and b that appear to be built by both silicate and sulfur volcanism a 100 km long flow field formed sometime after the 1979 voyager flybys which appears to be a site of promethean style compound flows flow front so2 plumes and adjacent sulfur flows larger possibly stealthy plumes have on at least one occasion during the galileo mission tapped a source that probably includes s and or cl to produce a red pyroclastic deposit from the same vent from which silicate lavas were erupted the thor eruptive center which may have been active prior to voyager became active again during the galileo mission between may and august 2001 a pillanian style eruption at thor included the tallest plume observed to date on io at least 500 km high and new dark lava flows the plume produced a central dark pyroclastic deposit probably silicate rich and an outlying white diffuse ring that is so2 rich mapping shows that several of the new dark lava flows around the plume vent have reoccupied sites of earlier flows unlike most of the other pillanian eruptions observed during the galileo mission the 2001 thor eruption did not produce a large red ring deposit indicating a relative lack of s and or cl gases interacting with the magma during that eruption between these two eruptive centers are two paterae thomagata and reshef thomagata patera is located on a large shield like mesa and shows no signs of activity in contrast reshef patera is located on a large irregular mesa that is apparently undergoing degradation through erosion perhaps from so2 sapping or chemical decomposition of sulfur rich material from multiple secondary volcanic centers

modelling net erosion responses to enviroclimatic changes recorded upon multisecular timescales land use change has been recognized throughout the earth as one of the most important factors influencing the occurrence of rainfall driven geomorphological processes however relating the occurrence of historical soil erosion rates is difficult because of the lack of long term research projects in river basins also complex models are not adequate to reconstruct erosion rate changes because they require significant input data not always available on long timescales given the problems with assessing sediment yield using complex erosion models the objective of this study is to explore a parsimonious scale adapted erosion model adt from the original thornes and douglas algorithms which aims at reconstruction of annual net erosion ane upon multisecular timescales as a test site the calore river basin 3015 km 2 in southern italy provides a peculiar and unique opportunity for modelling erosion responses to climate and land cover changes where input data generation and interpretation results were also supported by documented hydrogeomorphological events that occurred before and after land deforestation in this way aneadt values were reconstructed for the period 1675 2004 by using precipitation indexes complemented by recent instrumental records and by using land cover statistics from documented agrarian sources pulses of natural sedimentation in the predeforestation period have been related to vesuvius volcanic activity and changes in rainstorm frequency after deforestation the basin system became unstable with sudden fluctuations in the hydrogeomorphological regime contributing significantly to increased erosion and in turn sediment transport sequences via river drainage towards the tyrrhenian coast

geologic mapping of the hi iaka and shamshu regions of io abstract we produced regional geologic maps of the hi iaka and shamshu regions of io s antijovian hemisphere using galileo mission data to assess the geologic processes that are involved in the formation of io s mountains and volcanic centers observations reveal that these regions are characterized by several types of volcanic activity and features whose orientation and texture indicate tectonic activity among the volcanic features are multiple hotspots and volcanic vents detected by galileo one at each of the major paterae hi iaka shamshu and tawhaki we mapped four primary types of geologic units flows paterae floors plains and mountains the flows and patera floors are similar but are subdivided based upon emplacement environments and mechanisms the floors of hi iaka and shamshu paterae have been partially resurfaced by dark lava flows although portions of the paterae floors appear bright and unchanged during the galileo mission this suggests that the floors did not undergo complete resurfacing as flooding lava lakes however the paterae do contain compound lava flow fields and show the greatest activity near the paterae walls a characteristic of pele type lava lakes mountain materials are tilted crustal blocks that exhibit varied degrees of degradation lineated mountains have characteristic en echelon grooves that likely formed as a result of gravitational sliding undivided mountains are partially grooved but exhibit evidence of slumping and are generally lower elevation than the lineated units debris lobes and aprons are representative of mottled mountain materials we have explored the possibility that north and south hi iaka mons were originally one structure we propose that strike slip faulting and subsequent rifting separated the mountain units and created a depression which by further extension during the rifting event became hi iaka patera this type of rifting and depression formation is similar to the mechanism of formation of terrestrial pull apart basins with comparison to other regional maps of io and global studies of paterae and mountains this work provides insight into the general geologic evolution of io

post solidification cooling and the age of io s lava flows abstract the modeling of thermal emission from active lava flows must account for the cooling of the lava after solidification models of lava cooling applied to data collected by the galileo spacecraft have until now not taken this into consideration this is a flaw as lava flows on io are thought to be relatively thin with a range in thickness from 1 to 13 m once a flow is completely solidified a rapid process on a geological time scale the surface cools faster than the surface of a partially molten flow cooling via the base of the lava flow is also important and accelerates the solidification of the flow compared to the rate for the semi infinite approximation which is only valid for very deep lava bodies we introduce a new model which incorporates the solidification and basal cooling features this model gives a superior reproduction of the cooling of the 1997 pillan lava flows on io observed by the galileo spacecraft we also use the new model to determine what observations are necessary to constrain lava emplacement style at loki patera flows exhibit different cooling profiles from that expected from a lava lake we model cooling with a finite element code and make quantitative predictions for the behavior of lava flows and other lava bodies that can be tested against observations both on io and earth for example a 10 m thick ultramafic flow like those emplaced at pillan patera in 1997 solidifies in 450 days at which point the surface temperature has cooled to 280 k and takes another 390 days to cool to 249 k observations over a sufficient period of time reveal divergent cooling trends for different lava bodies examples lava flows and lava lakes have different cooling trends after the flow has solidified flows cool faster thin flows solidify and cool faster than flows of greater thickness the model can therefore be used as a diagnostic tool for constraining possible emplacement mechanisms and compositions of bodies of lava in remote sensing data

io heat flow from dark paterae abstract dark paterae on the jovian satellite io are evidence of recent volcanic activity some paterae appear to be entirely filled with dark volcanic material while others have only partially darkened floors dark paterae have area and heat flow longitudinal distributions that are bimodal as well as anti correlated with the longitudinal distribution of mountains on io at a global scale as part of our study of io s total heat flow we have examined the darkest paterae and quantified their thermal emission in order to assess their contribution this is the first time that the areas of the dark material in these paterae have been measured with such precision and correlated with their thermal emission dark paterae yield a significantly larger contribution to io s heat flow than dark volcanic fields dark paterae including loki patera yield at least 4 10 13 w or 40 of io s total heat flow in comparison dark flow fields yield 10 13 w or 10 of io s total heat flow of the total heat loss from dark paterae loki patera alone yields 10 13 w or 10 of io s total thermal emission

simulation of the atmospheric thermal circulation of a martian volcano using a mesoscale numerical model mesoscale 100 km atmospheric phenomena are ubiquitous on mars as revealed by mars orbiter camera images numerical models provide an important means of investigating martian atmospheric dynamics for which data availability is limited but the resolution of general circulation models which are traditionally used for such research is not sufficient to resolve mesoscale phenomena to provide better understanding of these relatively small scale phenomena mesoscale models have recently been introduced here we simulate the mesoscale spiral dust cloud observed over the caldera of the volcano arsia mons by using the mars regional atmospheric modelling system our simulation uses a hierarchy of nested models with grid sizes ranging from 240 km to 3 km and reveals that the dust cloud is an indicator of a greater but optically thin thermal circulation that reaches heights of up to 30 km and transports dust horizontally over thousands of kilometres

geologic mapping of the zal region of io abstract we produced a regional geologic map of the zal region of io s antijovian hemisphere using galileo mission data we discuss the geologic features summarize the map units and structures that are present discuss the nature of volcanic activity and present an analysis of the volcanic tectonic and gradational processes that affect the region the zal region consists of five primary types of geologic materials plains mountains paterae floors flows and diffuse deposits the flows and patera floors are similar but are subdivided based on uncertainties regarding emplacement environments and mechanisms the zal region includes two hotspots detected by galileo one along the western scarp of the zal patera volcano and one at the rustam patera volcano name submitted to iau a third hotspot at the nearby at am patera volcano name submitted to iau is the source of diffuse and pyroclastic materials that blanket north zal mons the western bounding scarp of zal patera is the location of a fissure vent that is the source of multiple silicate lava flows the floor of zal patera has been partially resurfaced by dark lava flows although portions of the patera floor appear bright and unchanged during the galileo mission this suggests that the floor did not undergo complete resurfacing as a flooding lava lake but does contain a compound flow field mountain materials exhibit stages of degradation lineated material degrades into mottled material we have explored the possibility that north and south zal mons were originally one structure we propose that strike slip faulting and subsequent rifting separated the mountain units opened a fissure which serves as a vent for lava flow and created a depression which by further extension during the rifting event became zal patera with comparison to other regional maps of io this work provides insight into the general geologic evolution of io

erosion under climate and human pressures an alpine lake sediment perspective we review the scientific efforts over the last decades to reconstruct erosion from continuous alpine lake sediment records we focused both on methodological issues showing the growing importance of non destructive high resolution approaches xrf core scanner as well as progresses in the understanding of processes leading to the creation of an erosion signal in lakes we distinguish continuous records from event records both provide complementary information but need to be studied with different approaches continuous regionally relevant records proved to be particularly pertinent to document regional erosion patterns throughout the holocene in particular applying the source to sink approach event based approaches demonstrated and took advantage of the strong non linearity of sediment transport in high altitude catchment areas this led to flood frequency and intensity reconstructions highlighting the influence of climate change upon flood dynamics in the mountain the combination of different record types both in terms of location high vs low elevation sedimentology high vs low terrigenous contribution and significance local vs regional is one of the main outputs of this paper it allows the establishment of comprehensive histories of nw french alps erosion but also and consequently soil dynamics and hydrological patterns throughout the holocene we also discuss the influence of glacier dynamics one of the major agents of erosion in the alps a major feature is the growing human influence upon erosion at a local scale since at least the middle of the bronze age 3500 cal bp however and according to the regional record from lake bourget only few periods of rising erosion at local scales generated a regional record that can be discriminated from wetter climatic periods among them the period between 200 bce and 400 ad appeared to be marked by a generalised rise in human triggered erosion at local scales in the northern french alps this review highlights the importance of modern high resolution and interdisciplinary studies of lake sediments in order to better understand the complex relationships between humans climate and the earth system in general we strongly argue that regional integration of data is now required to move a step further such an integration is easier with cost and time effective methods as well as after a better definition of approaches and their limits this should lead to a stronger collaboration between paleo data producers and modellers in the near future

evaluation of sulfur flow emplacement on io from galileo data and numerical modeling galileo images of bright lava flows surrounding emakong patera have been analyzed and numerical modeling has been performed to assess whether these flows could have resulted from the emplacement of sulfur lavas on io images from the solid state imaging ssi camera show that these bright white to yellow emakong flows are up to 370 km long and contain dark sinuous features that are interpreted to be lava conduits 300 500 m wide and 100 km long near infrared mapping spectrometer nims thermal emission data yield a color temperature estimate of 344 k 60 k 131 c within the emakong caldera we suggest that these bright flows likely resulted from either sulfur lavas or silicate lavas that have undergone extensive cooling pyroclastic mantling and or alteration with bright sulfurous materials the emakong bright flows have estimated volumes of 250 350 km3 similar to some of the smaller columbia river basalt flows if the emakong flows did result from effusive sulfur eruptions then they are orders of magnitude greater in volume than any terrestrial sulfur flows our numerical modeling results show that sulfur lavas on io could have been emplaced as turbulent flows which were capable of traveling tens to hundreds of kilometers consistent with the predictions of sagan 1979 and fink et al 1983 our modeled flow distances are also consistent with the measured lengths of the emakong channels and bright flows modeled thermal erosion rates are 1 4 m d 1 for flows erupted at 140 180 c which are consistent with the melting rates of kieffer et al 2000 the emakong channels could be thermal erosional in nature however the morphologic signatures of thermal erosion channels cannot be discerned from available images there are planned galileo flybys of io in 2001 which provide excellent opportunities to obtain high resolution morphologic and color data of emakong patera such observations could along with further modeling provide additional information to better constrain whether sulfur lavas produced the emakong flows

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