co2 emissions related to the yellowstone volcanic system 2 statistical sampling total degassing and transport mechanisms a stratified adaptive sampling plan was designed to estimate co2 degassing in yellowstone national park and was applied in the mud volcano thermal area the stratified component of the sampling design focused effort in thermal areas and the adaptive component in high flux regions yet neither sampling technique biased the estimate of total degassing both diffuse soil fluxes up to 30 000 g m 2d 1 and emission rates from thermal vents up to 1 7 108 mol yr 1 were measured in thermal areas soil fluxes observed in most nonthermal regions were similar to values reported for conifer forests 15 g m 2 d 1 however through adaptive sampling high flux vegetated sites were identified in mud volcano that likely would not have been found if sampling was focused in obvious thermal or altered regions a simple model applied to flux measurements suggests that 40 of the analyzed measurements were dominated by possible advective transport and 30 by diffusive transport isotopic signatures of soil co2 generally suggest a deep origin 13c 2 3 to 0 0 in thermal areas and biogenic origin 13c 20 5 in nonthermal low flux areas vent emissions accounted for 32 63 of the total degassing observed at mud volcano 2 4 to 4 0 109 mol yr 1 the largest source of error in the estimation of total degassing factor of 2 resulted because the population distribution of thermal feature emissions was indeterminate total co2 emissions at mud volcano are comparable to other hydrothermal regions worldwide suggesting that the yellowstone volcanic system is likely a large contributor to global volcanic metamoohic hydrothermal vmh emissions

monitoring gas and heat emissions at norris geyser basin yellowstone national park usa based on a combined eddy covariance and multi gas approach abstract we quantified gas and heat emissions in an acid sulfate vapor dominated area 0 04 km2 of norris geyser basin located just north of the 0 63 ma yellowstone caldera and near an area of anomalous uplift from 14 may to 3 october 2016 an eddy covariance system measured half hourly co2 h2o and sensible h and latent le heat fluxes and a multi gas instrument measured 1 hz frequency atmospheric h2o co2 and h2s volumetric mixing ratios we also measured soil co2 fluxes using the accumulation chamber method and temperature profiles on a grid and collected fumarole gas samples for geochemical analysis eddy covariance co2 fluxes ranged from 56 to 885 g m 2 d 1 using wavelet analysis average daily eddy covariance co2 fluxes were locally correlated with average daily environmental parameters on several day to monthly time scales estimates of co2 emission rate from the study area ranged from 8 6 t d 1 based on eddy covariance measurements to 9 8 t d 1 based on accumulation chamber measurements eddy covariance water vapor fluxes ranged from 1178 to 24 600 g m 2 d 1 nighttime h and le were considered representative of hydrothermal heat fluxes and ranged from 4 to 183 and 38 to 504 w m 2 respectively the total hydrothermal heat emission rate h le radiant estimated for the study area was 11 6 mw and le contributed 69 of the output the mean standard deviation of h2o co2 and h2s mixing ratios measured by the multi gas system were 9 3 3 1 parts per thousand 467 61 ppmv and 0 5 0 6 ppmv respectively and variations in the gas compositions were strongly correlated with diurnal variations in environmental parameters wind speed and direction atmospheric temperature after removing ambient h2o and co2 the observed variations in the multi gas data could be explained by the mixing of relatively h2o co2 h2s rich fumarole gases with co2 rich and h2o h2s poor soil gases the fumarole h2o co2 and co2 h2s end member ratios 101 7 and 27 1 respectively on average were invariant during the measurement period and fell within the range of values measured in direct fumarole gas samples the soil gas h2o co2 end member ratios 15 30 were variable and low relative to the fumarole end member likely resulting from water vapor loss during cooling and condensation in the shallow subsurface whereas the co2 h2s end member ratio was high 160 presumably related to transport of co2 dominated soil gas emissions mixed with trace fumarolic emissions to the multi gas station nighttime eddy covariance ratios of h2o to co2 flux were typically between the soil gas and fumarole end member h2o co2 ratios defined by multi gas measurements overall the combined eddy covariance and multi gas approach provides a powerful tool for quasi continuous measurements of gas and heat emissions for improved volcano hydrothermal monitoring

finite fault inversion of dinsar coseismic displacement of the 2009 l aquila earthquake central italy 1 we define the geometric and kinematic characteristics of the fault activated during the mw 6 3 6 april 2009 l aquila earthquake from the modeling of envisat and cosmo skymed the first ever x band interferogram inverted for a coseismic dislocation study dinsar interferograms our best fit solution for the main shock is represented by a normal fault 16 km long and 12 km wide with a small right lateral component dipping 47 sw with a maximum slip of 90 cm although the seismic dislocation probably ended at 1 km depth the updip projection of the fault plane corresponds to the northern segment of the mapped paganica s demetrio fault where alignment of surface breaks was observed in the field the absence of this fault in existing seismic source catalogues suggests that an improved approach involving detailed surface and subsurface geological and geophysical investigations is needed for a better assessment of the seismic hazard at the local scale

total co2 output from vulcano island aeolian islands italy 1 total co2 output from fumaroles soil gas bubbling gas discharges and water dissolved gases discharged from the island was estimated for vulcano island italy the co2 emission from fumaroles from the la fossa summit crater was estimated from the so2 crater output while co2 discharged through diffuse soil emission was quantified on the basis of 730 measurements of co2 fluxes from the soil of the island performed by using the accumulation chamber method the results indicate an overall output of 500 t day 1 of co2 from the island the main contribution to the total co2 output comes from the summit area of the la fossa cone 453 t day 1 with 362 t day 1 from crater fumaroles and 91 t day 1 from crater soil degassing the release of co2 from peripheral areas is 20 t day 1 by soil degassing palizzi and istmo areas mainly an amount comparable to both the contribution of water dissolved co2 6 t day 1 as well as to seawater bubbling co2 4 t day 1 measured in the istmo area presented data september 2007 refer to a period of moderate solphataric activity when the fumaroles temperature were 450 c and gas water molar ratio of fumaroles was up to 0 16 the calculated total co2emission allows the estimation of the mass release and related thermal energy from the volcanic hydrothermal system

hydrogeochemistry of the meade thrust allochthon southeastern idaho u s a and its relevance to stratigraphic and structural groundwater flow control abstract groundwater flow patterns in the folded carbonate sandy and shaly strata of the meade thrust allochthon southeastern idaho u s a were investigated using classical geochemical and isotopic techniques samples from 38 springs and wells were analyzed for major ions 18 o and 2 h and samples from nine springs were analyzed for radiocarbon content and 13 c two major groundwater regimes were identified aquifers of the upper regime tier one are restricted to strata above the phosphoria formation their waters circulate within a few hundred meters of the surface discharge waters are of recent meteoric origin having temperatures of 12 c or less and are generally undersaturated with respect to calcite and have ca mg of 2 5 groundwater flow is generally bedding plane controlled and discharge is along bedding and thrust splay surfaces no indication of significant groundwater circulation between this and underlying strata tier two was found aquifers of the lower regime tier two are restricted to consolidated strata below the phosphoria formation which generally hydraulically isolates them from tier one aquifers groundwater flow in tier two circulates as much as 1900 m below land surface discharge waters have high temperatures up to 26 c stable isotopic data suggest the temperatures have not been elevated above 100 c the discharge waters are saturated with respect to calcite have ca mg of 3 4 and have mean subsurface residence times of 12 500 20 500 yr estimated from radiocarbon data these spring waters are evolving co 2 g possibly from the upward diffusion along faults and have deposited massive amounts of travertine groundwater flow is generally bedding plane controlled and discharge is along deep seated extension and thrust faults based on maximum circulation depth and estimated depth of the meade thrust fault tier two aquifers appear to be contained within the allochthon with no evidence found suggesting they communicate with deeper circulating systems tier three

diffuse emission of carbon dioxide methane and helium 3 from teide volcano tenerife canary islands diffuse emission of co2 ch4 and he was investigated in the summit crater of teide volcano tenerife canary islands the results indicate that teide volcano releases abundant co2 not only from its active crater but also from its flanks as diffuse soil emanations the spatial distribution of these emanations correlates quite closely with that of geothermal anomalies and manifestations our flux measurements indicate a total output of 380 ton day 1 of co2 and 1 6 on day 1 of ch4 by diffuse degassing from the he co2 ratios and the co2 flux we estimate a diffuse he flux of 0 052 mol year 1 isotopic analysis of carbon in soil gas samples from sites of high soil co2 flux indicates a magmatic origin for the co2 also reported by high he 4he ratios of 5 50 and 5 87 ra the origin of methane is more uncertain with low 13c values suggesting a biogenic contribution

seismic moment tensors of the april 2009 l aquila central italy earthquake sequence summary on 2009 april 6 the central apennines were hit by an mw 6 3 earthquake the region had been shaken since 2008 october by seismic activity that culminated in two foreshocks with mw 4 1 week and a few hours before the main shock we computed seismic moment tensors for 26 events with mw between 3 9 and 6 3 using the regional centroid moment tensor rcmt scheme most of these source parameters have been computed within 1 hr after the earthquake and rapidly revised successively the focal mechanisms are all extensional with a variable and sometimes significant strike slip component this geometry agrees with the ne sw extensional deformation of the apennines known from previous seismic and geodetic observations events group into three clusters those located in the southern area have larger centroid depths and a wider distribution of t axis directions these differences suggest that towards south a different fault system was activated with respect to the sw dipping normal faults beneath l aquila and more to the north

temporal variation of seismic velocity and anisotropy before the 2009 mw 6 3 l aquila earthquake italy we describe a set of seismological observations of the foreshock sequence preceding the 6 april 2009 m w 6 3 l9aquila earthquake the dense configuration of the seismic network in the epicenter area and the occurrence of a long foreshock sequence provide the opportunity for a detailed reconstruction of the preparatory phase of the main shock approaching the earthquake we observed clear variations in the seismic wave propagation properties the elastic properties of rocks in the fault region underwent a sharp change about a week before the earthquake from our observations we infer that a complex sequence of dilatancy diffusion processes takes place and that fluids play a key role in the fault failure process

spatial and temporal variations of co2 emissions from the active fault zones in the capital area of china abstract the chemical and isotopic composition of 26 soil gas wells and 11 springs along the active fault zones in the capital area of china was determined to investigate the origin of co2 the spatial and temporal variations of co2 emission and their mechanisms the chemical and isotopic data indicated that biogenic co2 was the primary source for co2 from the soil gas wells in both the basin and orogen regions the crust derived and mantle derived co2 could have ascended through the deep cut faults and got into the springs with a few diffusing into the soil gas wells minor air could have intruded into the soil gas wells in the orogen region through the faults cutting the surface owing to the barometric pressure fluctuation relatively high he concentration co2 concentration and flux of soil gas from wells were observed in the basin region than those in the orogen region a significant amount of co2 is produced during the process of oxidation of organic matter in the basin where the organic matter accumulates in thick clayey strata further amounts of co2 are produced by interactions between groundwaters and carbonates which are widely represented in the basin region and by intruded air into the soil gas wells in the orogen region due to barometric pressure fluctuations temporal variations of co2 concentration and co2 flux were observed in soil gas wells in the basin region where seismic activity is more frequent compared to those in the orogen indicating that seismic activity could be responsible for the jumpily temporal variations of co2 concentration and flux in wells monitoring activities of soil gas co2 concentrations and co2 fluxes in active fault zones should be carried out

monitoring volcanic hazard using eddy covariance at solfatara volcano naples italy an eddy covariance ec station was deployed at solfatara crater italy june 8 25 2001 to assess if ec could reliably monitor co2 fluxes continuously at this site deployment at six different locations within the crater allowed areas of focused gas venting to be variably included in the measured flux turbulent ec fluxes calculated in 30 min averages varied between 950 and 4460 g co2 m 2 d 1 the highest measurements were made downwind of degassing pools comparing turbulent fluxes with chamber measurements of surface fluxes using footprint models in diffuse degassing regions yielded an average difference of 0 4 indicating that ec measurements are representative of surface fluxes at this volcanic site similar comparisons made downwind of degassing pools yielded emission rates from 12 to 27 t co2 d 1 for these features reliable ec measurements i e measurements with sufficient and stationary turbulence were obtained primarily during daytime hours 08 00 and 20 00 local time when the wind speed exceeded 2 m s 1 daily average ec fluxes varied by 50 and variations were likely correlated to changes in atmospheric pressure variations in co2 emissions due to volcanic processes at depth would have to be on the same order of magnitude as the measured diurnal variability in order to be useful in predicting volcanic hazard first order models of magma emplacement suggest that emissions could exceed this rate for reasonable assumptions of magma movement ec therefore provides a useful method of monitoring volcanic hazard at solfatara further ec can monitor significantly larger areas than can be monitored by previous methods

detection of a locked zone at depth on the parkfield california segment of the san andreas fault the parkfield california segment of the san andreas fault is transitional in character between the creeping segment of the fault to the northwest and the locked carrizo plain segment to the southeast the rate of shallow fault slip decreases from 25 30 mm yr northwest of the epicenter of the 1966 parkfield earthquake to zero at the southeastern end of the 1966 rupture zone data from a network of trilateration lines spanning the san andreas fault near parkfield and extending to the pacific coast near san luis obispo shed light on the rate of fault slip at depth since the 1966 earthquake in this study average rates of line length change and shallow fault slip were inverted to determine the slip rate at depth on the parkfield fault segment the fault is taken to be a vertical surface with unknown distribution of strike slip displacement in an elastic half space a striking result of the inversions is that all solutions providing acceptable fits to the data exhibit a locked zone essentially coincident with the rupture surface of the 1966 parkfield earthquake the data require that the locked zone extend nearly as far north as the 1966 epicenter however the vertical extent of the locked zone is not well resolved over much of the parkfield segment the fault is slipping faster at the earth s surface than it is at seismogenic depths in order to fit the trilateration measurements it is necessary to include a component of contraction normal to the trend of the san andreas the inversion results suggest a spatially uniform normal strain of 0 06 strain yr the orientation of the contraction is compatible with geologic and seismic evidence of active folding and reverse faulting in the region the magnitude of the contraction is consistent with convergence rates inferred from global plate motion models

pore pressure migration along a normal fault system resolved by time repeated seismic tomography in this study we outline the space and time variations of body wave velocities during one of the best documented series of normal faulting earthquakes the 1997 umbria marche sequence in central italy we show the first ever observations of rock fracturing and fluid overpressure propagation along a fault system by using space time resolved variations of vp vs anomalies four dimensional variations that accompany earthquake migration and precede large aftershocks the vp vs increase observed before the mid october earthquakes was related to a pore pressure increase on fluid filled cracks in the volume around the fault we also document that such variations are measurable only by using s and p wave arrival times

carbon dioxide earth degassing and seismogenesis in central and southern italy 1 we present the first regional map of co2 earth degassing from a large area most of central and south italy derived from the carbon of deep provenance dissolved in the main springs of the region the investigation shows that a globally significant amount of deeply derived co2 10 of the estimated global co2 emitted from subaerial volcanoes is released by two large areas located in western italy the anomalous flux of co2 suddenly disappears in the apennine in correspondence to a narrow band where most of seismicity concentrates here at depth the gas accumulates in crustal traps generating co2 overpressurized reservoirs which induce seismicity

the 2009 l aquila central italy mw6 3 earthquake main shock and aftershocks 1 a m w 6 3 earthquake struck on april 6 2009 the abruzzi region central italy producing vast damage in the l aquila town and surroundings in this paper we present the location and geometry of the fault system as obtained by the analysis of main shock and aftershocks recorded by permanent and temporary networks the distribution of aftershocks 712 selected events with m l 2 3 and 20 with m l 4 0 defines a complex 40 km long nw trending extensional structure the main shock fault segment extends for 15 18 km and dips at 45 to the sw between 10 and 2 km depth the extent of aftershocks coincides with the surface trace of the paganica fault a poorly known normal fault that after the event has been quoted to accommodate the extension of the area we observe a migration of seismicity to the north on an echelon fault that can rupture in future large earthquakes

six week time series of eddy covariance co2 flux at mammoth mountain california performance evaluation and role of meteorological forcing co sub 2 and heat fluxes were measured over a six week period 09 08 2006 to 10 24 2006 by the eddy covariance ec technique at the horseshoe lake tree kill hltk mammoth mountain ca a site with complex terrain and high spatially heterogeneous co sub 2 emission rates ec co sub 2 fluxes ranged from 218 to 3500 g m sup 2 d sup 1 mean 1346 g m sup 2 d sup 1 using footprint modeling ec co sub 2 fluxes were compared to co sub 2 fluxes measured by the chamber method on a grid repeatedly over a 10 day period half hour ec co sub 2 fluxes were moderately correlated r sup 2 0 42 with chamber fluxes whereas average daily ec co sub 2 fluxes were well correlated r sup 2 0 70 with chamber measurements average daily ec co sub 2 fluxes were correlated with both average daily wind speed and atmospheric pressure relationships were similar to those observed between chamber co sub 2 fluxes and the atmospheric parameters over a comparable time period energy balance closure was assessed by statistical regression of ec energy fluxes sensible and latent heat against available energy net radiation less soil heat flux while incomplete r sup 2 0 77 for 1 1 line the degree of energy balance closure fellmore within the range observed in many investigations conducted in contrasting ecosystems and climates results indicate that despite complexities presented by the hltk ec can be reliably used to monitor background variations in volcanic co sub 2 fluxes associated with meteorological forcing and presumably changes related to deeply derived processes such as volcanic activity less

the anatomy of the 2009 l aquila normal fault system central italy imaged by high resolution foreshock and aftershock locations 1 on 6 april 01 32 utc 2009 a mw 6 1 normal faulting earthquake struck the axial area of the abruzzo region in central italy we study the geometry of fault segments using high resolution foreshock and aftershock locations two main sw dipping segments the l aquila and campotosto faults forming an en echelon system 40 km long nw trending the 16 km long l aquila fault shows a planar geometry with constant dip 48 through the entire upper crust down to 10 km depth the campotosto fault activated by three events with 5 0 mw 5 2 shows a striking listric geometry composed by planar segments with different dips along depth rather than a smoothly curving single fault surface the investigation of the spatiotemporal evolution of foreshock activity within the crustal volume where the subsequent l aquila main shock nucleated allows us to image the progressive activation of the main fault plane from the beginning of 2009 the foreshocks activated the deepest portion of the fault until a week before the main shock when the largest foreshock mw 4 0 triggered a minor antithetic segment seismicity jumped back to the main plane a few hours before the main shock secondary synthetic and antithetic fault segments are present both on the hanging and footwall of the system the stress tensor obtained by inverting focal mechanisms of the largest events reveals a ne trending extension and the majority of the aftershocks are kinematically consistent deviations from the dominant extensional strain pattern are observed for those earthquakes activating minor structures

geochemistry and geothermometry of spring water from the blackfoot reservoir region southeastern idaho abstract the blackfoot reservoir region in southeastern idaho is recognized as a potential geothermal area because of the presence of several young rhyolite domes 50 000 years old quaternary basalt flows and warm springs north to northwest trending high angle normal faults of tertiary to holocene age appear to be the dominant structural control of spring activity surface spring water temperatures average 14 c except for a group of springs west of the reservoir mountains which average 33 c chemical geothermometers applied to fifty water samples give temperatures less than 75 c except for eight springs along the corral creek drainage the springs along corral creek have na k ca temperatures that average 354 c a direct result of high potassium concentrations in the water a correction for carbon dioxide applied to the na k ca geothermometer lowers the estimated temperatures of the anomalous springs to near the measured surface temperatures and na k ca mg temperatures for the anomalous springs are near 100 c mixing model calculations suggest that hot water with a temperature of approximately 120 c may be mixing with cooler more dilute water in the springs from the corral creek drainage a temperature supported by na k ca mg temperatures and mineral saturation temperatures stability relations of low temperature phases in the system indicate that the large concentrations of potassium in the eight anomalous springs are derived from reactions with the potassium bearing minerals muscovite and k feldspar carbon dioxide and hydrogen sulfide gases may be derived through the oxidation of organic matter accompanied by the reduction of sulfate concentrations of major and minor elements and gases found in springs of the blackfoot reservoir region are due to water rock reactions at temperatures less than 100 c based on spring geochemistry a geothermal reservoir of 100 c up to 120 c may exist at shallow less than 2 km depths in the blackfoot reservoir region

convective hydrothermal c02 emission from high heat flow regions abstract in addition to volatiles released from volcanoes the flux of co2 to the atmosphere from other sources e g metamorphism and subsurface magmatism represents an important aspect of the global carbon cycle we have obtained a direct estimate of the present day atmospheric co2 flux from convective hydrothermal systems within subaerial seismically active high heat flow regions geothermal systems of the salton trough california u s a and the taupo volcanic zone new zealand provide benchmarks for quantifying convective hydrothermal co2 fluxes from such regions co2 fluxes from the salton trough 109 mol yr 1 and the taupo volcanic zone 8 109 mol yr 1 were computed using data on convective heat flow and the temperatures and co2 concentrations of reservoir fluids the similarity in specific co2 flux 106 mol km 2 yr 1 from these two disparate geologic tectonic settings implies that this flux may be used as a baseline to compute convective hydrothermal co2 emission from other areas of high heat flow if this specific flux is integrated over high heat flow areas of the circum pacific and tethyan belts the total global co2 flux could equal or exceed 1012 mol yr 1 adding this flux to a present day volcanic co2 flux of 4 1012 mol yr 1 the total present day earth degassing flux could balance the amount of co2 consumed by chemical weathering 7 1012 mol yr 1

stress forecasting not predicting earthquakes a paradigm shift after 120 years of unsuccessful endeavor a paradigm shift is required before earthquakes can be predicted the most sensitive diagnostic of low level changes of stress in in situ rock variations in microcrack geometry can be monitored by analyzing shear wave splitting the suggested paradigm shift is that instead of investigating the source zone we monitor stress accumulation before earthquakes at possibly substantial distances from the source characteristic temporal variations of shear wave time delays have been observed in retrospect before 14 earthquakes worldwide on one occasion when changes were recognized early enough the time magnitude and fault break of an m 5 earthquake in southwest iceland were successfully stress forecast in a narrow time magnitude window such stress accumulation can be theoretically modeled and is believed to be at least partially understood when sufficient shear wave source earthquakes are available increasing time delays also show an abrupt decrease shortly before the impending earthquake occurs this is not fully understood but is thought to be caused by stress relaxation as microcracks coalesce onto the eventual fault break the new result confirming these ideas and justifying the paradigm shift is that logarithms of the durations of both increases and decreases in time delays are found to be proportional self similar to the magnitudes of impending earthquakes

shear wave splitting vp vs and gps during a time of enhanced activity at aso caldera kyushu 1 we performed shear wave splitting analyses and calculated vp vs ratios on local earthquakes recorded at seven stations around aso volcano japan between 2001 and 2008 the mean vp vs of 1 61 0 01 from all stations is among the lowest average values found anywhere in the world a temporal change of shear wave splitting fast polarization is observed at one station additionally spatial variations of shear wave splitting delay times and vp vs ratios show a correlation at three stations we suggest that stress controlled anisotropy dominates at these stations gps baselines and 2d strain reveal extension in the caldera in 2003 and compression before and after 2003 strain shortening axes indicate either a variation in regional stress or a local stress source that overprints the regional field in 2003 baseline changes correlate with periods of increased low frequency seismic activity located deeper than 15 km compaction and degassing of a previously reported sill at approximately 15 km depth could lead to constantly high pressure of volcanic gases over a wide area and explain the generally low vp vs ratios and the observed compression in the caldera we propose that a small volume of magma intruded into the sill in 2003 caused extension at the surface and triggered ash eruptions between 2003 and 2005 associated localized migration of gases in overpressured cracks with aspect ratios potentially 0 5 in the upper crust with porosities 0 1 could be the source of changes in seismic anisotropy and explain the slight variations observed in vp vs

geologic co2 input into groundwater and the atmosphere soda springs id usa abstract a set of co 2 flux geochemical and hydrologic measurement techniques was used to characterize the source of and quantify gaseous and dissolved co 2 discharges from the area of soda springs southeastern idaho an eddy covariance system was deployed for one month near a bubbling spring and measured net co 2 fluxes from 74 to 1147 g m 2 d 1 an inversion of measured eddy covariance co 2 fluxes and corresponding modeled source weight functions mapped the surface co 2 flux distribution within and quantified co 2 emission rate 24 9 t d 1 from a 0 05 km 2 area surrounding the spring soil co 2 fluxes 2 d 1 were measured within a 0 05 km 2 area of diffuse degassing using the accumulation chamber method the estimated co 2 emission rate from this area was 49 t d 1 a carbon mass balance approach was used to estimate dissolved co 2 discharges from contributing sources at nine springs and the soda springs geyser total dissolved inorganic carbon as co 2 discharge for all sampled groundwater features was 57 1 t d 1 of this quantity approximately 3 was derived from biogenic carbon dissolved in infiltrating groundwater 35 was derived from carbonate mineral dissolution within the aquifer s and 62 was derived from deep source s isotopic compositions of helium 1 74 2 37 r a and deeply derived carbon 13 c 3 suggested contribution of volatiles from mantle and carbonate sources assuming that the deeply derived co 2 discharge estimated for sampled groundwater features 35 t d 1 is representative of springs throughout the study area the total rate of deeply derived co 2 input into the groundwater system within this area could be 350 t d 1 similar to co 2 emission rates from a number of quiescent volcanoes

eddy covariance measurement of co2 flux to the atmosphere from an area of high volcanogenic emissions mammoth mountain california abstract three pilot studies were performed to assess application of the eddy covariance micrometeorological method in the measurement of carbon dioxide co 2 flux of volcanic origin the selected study area is one of high diffuse co 2 emission on mammoth mountain ca because terrain and source characteristics make this a complex setting for this type of measurement added consideration was given to source area and upwind fetch footprint analysis suggests that the eddy covariance measurements were representative of an upwind elliptical source area 3 8 10 3 m 2 which can vary with mean wind direction surface roughness and atmospheric stability co 2 flux averaged 8 16 mg m 2 s 1 0 7 1 4 kg m 2 day 1 eddy covariance measurements of flux were compared with surface chamber measurements made in separate studies geophys res lett 25 1998a 1947 eos trans 79 1998 f941 and were found to be similar

kinetics of co2 fluid rock reactions in a basalt aquifer soda springs idaho the dissolution of silicate minerals by co2 rich fluids and the subsequent precipitation of co2 as carbonate minerals represent a means of permanently storing anthropogenic co2 waste products in a solid and secure form modelling the progression of these reactions is hindered by our poor understanding of the rates of mineral dissolution precipitation reactions and mineral surface properties in natural systems this study evaluates the chemical evolution of groundwater flowing through a basalt aquifer which forms part of the leaking co2 charged system of the blackfoot volcanic field in south eastern idaho usa reaction progress is modelled using changes in groundwater chemistry by inverse mass balance techniques the co2 promoted fluid mineral reactions include the dissolution of primary plagioclase orthoclase pyroxene and gypsum which is balanced by the precipitation of secondary albite calcite zeolite kaolinite and silica mineral mole transfers and groundwater flow rates estimated from hydraulic head data are used to determine the kinetics of plagioclase and orthoclase feldspar dissolution plagioclase surface area measurements were determined using the evolution of the u series isotope ratios in the groundwater and are compared to published surface area measurements calculated rates of dissolution for plagioclase range from 2 4 10 12 to 4 6 10 16 mol m2 s and orthoclase from 2 0 10 13 to 6 8 10 16 mol m2 s respectively these feldspar reaction rates correlate with the degree of mineral fluid disequilibrium and are similar to the dissolution rates for these mineral measured in other natural co2 charged groundwater systems

high pore fluid pressures at bhuj inferred from 90 flips in shear wave polarizations summary shear wave splitting above local earthquakes in the aftershock zone of the 2001 m w7 6 bhuj earthquake display a spatial variation of anisotropy related to crack orientation at most seismic stations the fast polarization directions are approximately nne ssw parallel to the inferred directions of maximum horizontal stress suggesting the dilatancy induced anisotropy resulting from approximately stress aligned parallel vertical microcracks in contrast the fast polarization directions at station samkhyali skl very close to the epicentre of the main shock are fault parallel approximately ew and almost orthogonal to the stress aligned polarizations elsewhere ape modelling and observations elsewhere suggest that these are 90 flips in shearwave polarizations caused by propagation through microcracks containing fluids at critically high pore fluid pressures surrounding the seismically active fault plane the presence of high pore fluid pressures on all seismogenic faults also explains the high scatter in shear wave time delays the average path normalized delay time varies from 2 to 4 ms km 1 except at station skl where higher delays of up to 13 ms km 1 are found the large scatter in measured time delays is caused by cracks saturated with high pressure pore fluids these observations can be explained by the presence of both normal stress aligned and 90 flipped shear wave polarizations at bhuj this suggests that the kutch mainland fault is a major tectonic feature

tracing and quantifying magmatic carbon discharge in cold groundwaters lessons learned from mammoth mountain usa abstract a major campaign to quantify the magmatic carbon discharge in cold groundwaters around mammoth mountain volcano in eastern california was carried out from 1996 to 1999 the total water flow from all sampled cold springs was 1 8 10 7 m 3 yr draining an area that receives an estimated 2 5 10 7 m 3 yr of recharge suggesting that sample coverage of the groundwater system was essentially complete some of the waters contain magmatic helium with 3 he 4 he ratios as high as 4 5 times the atmospheric ratio and a magmatic component in the dissolved inorganic carbon dic can be identified in virtually every feature sampled many waters have a 14 c of 0 5 pmc a 13 c near 5 and contain high concentrations 20 50 mmol l of co 2 aq but are otherwise dilute specific conductance 100 300 s cm with low ph values between 5 and 6 such waters have previously escaped notice at mammoth mountain and possibly at many other volcanoes because co 2 is rapidly lost to the air as the water flows away from the springs leaving neutral ph waters containing only 1 3 mmol l hco 3 the total discharge of magmatic carbon in the cold groundwater system at mammoth mountain is 20 000 t yr as co 2 ranging seasonally from about 30 to 90 t day several types of evidence show that this high discharge of magmatic dic arose in part because of shallow dike intrusion in 1989 but also demonstrate that a long term discharge possibly half this magnitude 10 000 t yr predated that intrusion to sustain a 10 000 t yr dic discharge would require a magma intrusion rate of 0 057 km 3 per century assuming complete degassing of magma with 0 65 wt co 2 and a density of 2 7 t m 3 the geochemical data also identify a small

eddy covariance imaging of diffuse volcanic co2 emissions at mammoth mountain ca usa use of eddy covariance ec techniques to map the spatial distribution of diffuse volcanic co2 fluxes and quantify co2 emission rate was tested at the horseshoe lake tree kill area on mammoth mountain california usa ec measurements of co2 flux were made during september october 2010 and ranged from 85 to 1 766 g m 2 day 1 comparative maps of soil co2 flux were simulated and co2 emission rates estimated from three accumulation chamber ac co2 flux surveys least squares inversion of measured eddy covariance co2 fluxes and corresponding modeled source weight functions recovered 58 77 of the co2 emission rates estimated based on simulated ac soil co2 fluxes spatial distributions of modeled surface co2 fluxes based on ec and ac observations showed moderate to good correspondence r2 0 36 to 0 70 results provide a framework for automated monitoring of volcanic co2 emissions over relatively large areas

diffuse emission of co2 from the fossa crater vulcano island italy numerous measurements of co2 degassing from the soil carried out with the accumulation chamber method indicate that in the period april july 1995 the upper part of the fossa cone released a total output of 200 t d 1 of co2 which corresponds to approximately 1000 t d 1 of steam these large amounts of fluids are of the same order of magnitude as those released by the high temperature fumarolic field located inside the crater the spatial distribution of soil gas fluxes shows that the main structures releasing co2 are the inner slopes of the crater and a nw se line located ne of the crater rim which correspond to the main direction of vulcano island active faults the comparison of the co2 maps with the soil temperature distribution derived from both direct measurements and airborne infrared images indicates the occurrence of extensive condensation of fumarolic steam within the upper part of the fossa cone whose total amount is comparable to the rainfall budget part of the condensate which originates from this process contributes to the recharge of the phreatic aquifer of porto plain modifying the chemical and isotopic composition of the groundwater

temporal velocity changes in the crust associated with the great sumatra earthquakes abstract co and postseismic slip of the great earthquakes can give rise to temporal changes in the medium either due to strong ground motion damaging near surface sediment layer or stress perturbations modulating crack density and or fluid movement at depth such time varying crustal properties can result in fractional change in seismic velocity that can be probed from cross correlating waveforms and measuring their time lags within a repeating earthquake sequence this study analyzes lag times of high frequency 0 5 2 0 hz p and s coda waves as well as long period 0 03 0 1 hz surface waves from repeating aftershock sequences of the great 2004 sumatra andaman and 2005 nias simeulue earthquakes the observed lag times reveal several major characteristics 1 lag time series t of s coda for the 2004 sequences fluctuate around zero and are sometimes negative as a function of lapse time whereas t of s coda for the 2005 sequences exhibit a monotonic increase as a function of lapse time 2 average velocity reduction of s coda v s is about two times larger than that of p coda v p average velocity reduction of rayleigh waves v lr is 3 4 times larger than that of love waves v lq and 3 v s and v lr display temporal velocity recovery with calendar time especially for the 2005 sequences the form of temporal velocity recovery of v s of the 2005 sequences is similar to available displacement time series of the nearby geodetic station whereas we discuss potential artifacts such as source separation temporal changes of the noise field and instrument response observations collectively point to nonuniform temporal velocity reduction in the crust modulated by co or and postseismic slip of the 2004 2005 great earthquakes online material table of source parameters and figure showing tests on lag time measurements of long period rayleigh waves

quantification of carbon dioxide emissions of ciomadul the youngest volcano of the carpathian pannonian region eastern central europe romania abstract we provide the first high resolution co 2 flux data for the neogene to quaternary volcanic regions of the entire carpathian pannonian region eastern central europe and estimate the co 2 emission of the seemingly inactive ciomadul volcanic complex the youngest volcano of this area our estimate includes data from focused and diffuse co 2 emissions from soil the co 2 fluxes of focused emissions range between 277 and 8172 g d 1 corresponding to a co 2 output into the atmosphere between 0 1 and 2 98 t per year the investigated areas for diffuse soil gas emissions were characterized by wide range of co 2 flux values at apor baths ranging from 1 7 10 1 to 8 2 10 4 g m 2 d 1 while at l z re ti ranging between 1 43 and 3 8 10 4 g m 2 d 1 the highest co 2 focused gas fluxes at ciomadul were found at the periphery of the youngest volcanic complex which could be explained either by tectonic control across the brittle older volcanic edifices or by degassing from a deeper crustal zone resulting in co 2 flux at the periphery of the supposed melt bearing magma body beneath ciomadul the estimate of the total co 2 output in the area is 8 70 10 3 t y 1 and it is consistent with other long 10 kyr dormant volcanoes with similar age worldwide such as in italy and usa taking into account the isotopic composition of the gases that indicate deep origin of the co 2 emissions this yields further support that ciomadul may be considered indeed a dormant or pams volcano volcano with potentially active magma storage rather than an inactive one furthermore hazard of co 2 outpourings has to be taken into account and it has to be communicated to the visitors finally we suggest that co 2 output of dormant volcanic systems has to be also accounted in the estimation of the global volcanic co 2 budget

flux measurements of nonvolcanic co2 emission from some vents in central italy in central italy nonvolcanic co2 is discharged from many areas of focused degassing vents and associated strong diffuse emission and from high pco2 groundwater we estimate that there are at least 100 co2 vents in central italy many of which have a history of lethality to animals and humans the gas vents are extremely efficient pathways for transporting large amounts of deeply derived co2 from gas reservoirs to the surface as co2 fluxes from these vents were heretofore unmeasured several complementary methods were developed to measure the co2 flux from seven of these vents which cumulatively discharge 3 1 109 mol yr 1 co2 472 t d 1 considering all of the vents in central italy the total co2 flux from vents alone may be similar to the co2 emission from the taupo volcanic zone in new zealand 1010 mol yr 1 1200 t d 1 and other areas of high heat flow summing the co2 discharged from vents areas of diffuse co2 degassing and degassing of high pco2 groundwater we provisionally estimate that the total nonvolcanic co2 flux to the atmosphere in central italy may be 1011 mol yr 1 12 000 t d 1

rate of diffuse carbon dioxide earth degassing estimated from carbon balance of regional aquifers the case of central apennine italy central italy is characterized by an anomalous flux of deeply derived co2 in the western tyrrhenian sector of central italy co2 degassing occurs mainly from focused emissions vents and strong diffuse degassing and thermal springs whereas in the eastern apennine area deep co2 is dissolved in cold groundwaters of regional aquifers hosted by mesozoic carbonate evaporite formations influx of deep co2 into 12 carbonate aquifers 12 500 km2 of the central apennine is computed through a carbon mass balance that couples aquifer geochemistry with isotopic and hydrogeological data mass balance calculations estimate that 6 5 1010 mol yr 1 of inorganic carbon are dissolved in the studied aquifers approximately 23 of this amount derives from biological sources active during the infiltration of the recharge waters 36 comes from carbonate dissolution while 41 is representative of deep carbon sources characterized by a common isotopic signature 13c 3 the calculated deep co2 influx rate ranges from 105 to 107 mol yr 1 km 2 increasing regionally from east to west in the study area

multi scale observations of the variability of magmatic co2 emissions mammoth mountain ca usa abstract one of the primary indicators of volcanic unrest at mammoth mountain is diffuse emission of magmatic co 2 which can effectively track this unrest if its variability in space and time and relationship to near surface meteorological and hydrologic phenomena versus those occurring at depth beneath the mountain are understood in june october 2013 we conducted accumulation chamber soil co 2 flux surveys and made half hourly co 2 flux measurements with automated eddy covariance and accumulation chamber auto chamber instrumentation at the largest area of diffuse co 2 degassing on mammoth mountain horseshoe lake tree kill hltk estimated co 2 emission rates for hltk based on 20 june 30 july and 24 25 october soil co 2 flux surveys were 165 172 and 231 t d 1 respectively the average june october co 2 emission rate estimated for this area was 123 t d 1 based on an inversion of 4527 eddy covariance co 2 flux measurements and corresponding modeled source weight functions average daily eddy covariance and auto chamber co 2 fluxes consistently declined over the four month observation time wavelet analysis of auto chamber co 2 flux and environmental parameter time series was used to evaluate the periodicity of and local correlation between these variables in time frequency space overall co 2 emissions at hltk were highly dynamic displaying short term hourly to weekly temporal variability related to meteorological and hydrologic changes as well as long term monthly to multi year variations related to migration of co 2 rich magmatic fluids beneath the volcano accumulation chamber soil co 2 flux surveys were also conducted in the four additional areas of diffuse co 2 degassing on mammoth mountain in july august 2013 summing co 2 emission rates for all five areas yielded a total for the mountain of 311 t d 1 which may suggest that emissions returned to 1998 2009 levels following an increase from 2009 to 2011

introduction to the special issue on frontiers in gas geochemistry abstract the study of the geochemistry of gases pervades the earth and environmental sciences this is due in no small measure to the well established thermodynamic properties of gases which allow their application to a variety of processes occurring over a wide spectrum of natural conditions in this respect both major and associated minor gases have been proven useful indeed the trace gases have been particularly important given their role as sensitive geochemical tracers examples where gas geochemistry places key constraints on geochemical processes include the degassing history of the solid earth to form the atmosphere and oceans the origin and migration characteristics of hydrocarbon deposits the scale of climate variability the p t characteristics of geothermal reservoirs and the dynamics of the earthquake cycle and volcanic activity to name but a few this volume continues this rich tradition with an eclectic selection of papers aimed at exploring and exploiting gas geochemistry over a myriad set of research themes

diffuse emission of co2 from miyakejima volcano japan abstract two soil gas surveys were carried out in may and september 1998 at miyakejima volcano in the izu mariana arc japan co 2 flux values for may and september surveys ranged from 0 1 to 18 150 g m 2 day 1 and from 0 1 to 9685 g m 2 day 1 respectively statistical graphical analysis showed three overlapping populations the spatial distribution of these emissions correlated quite closely with the geothermal and geological characteristics of the studied area the structure releasing higher co 2 is the summit cone oyama and surrounding areas where the most obvious geothermal features occur a total output about 100 150 t day 1 is estimated from this area a good correlation was observed between soil co 2 flux and soil temperature at the summit caldera indicating extensive condensation of fumarolic steam within the upper part of miyakejima carbon isotopic analysis of selected samples inside the summit caldera 13 c co 2 0 90 to 5 70 suggests a mixing of carbon derived from marine limestone and magmatic co 2 while a clear biogenic origin 13 c co 2 14 76 to 25 52 is observed for the diffuse degassing of co 2 outside summit caldera

sedimentation on the inner shelf of the east china sea magnetic properties diagenesis and paleoclimate implications abstract high resolution magnetic analysis was performed on the 19 22 m core md06 3040 27 43 3663 n 121 46 8822 e 46 m water depth from the east china sea ecs inner continental shelf which was recovered during the images xiv md155 marco polo 2 cruise of the r v marion dufresne ipev magnetic grains are mainly transported to the inner shelf from erosion on mainland china delivered by the yangtze river nine 14 c ams dates indicate that the core spans about the last 10 4 ka with an average sedimentation rate of nearly 2 mm yr the primary magnetic mineral assemblage of the uppermost sediments contains magnetite with some contributions from hematite and greigite two main stepwise changes are observed in the magnetic mineral content due to post depositional reductive diagenesis the first occurs from the top of the core to 3 5 m and is characterized by reduction of both the magnetite and hematite contents the second occurs at 8 45 9 m and is characterized by a loss of fine grained ferrimagnetic material variations in the magnetic mineral content of this core are related to geochemical and redox environment changes in the ecs through the oxic suboxic sulfidic methanic zones from top to bottom despite significant reduction of a large amount of the ferrimagnetic mineral content due to diagenesis intervals characterized by lower magnetic mineral concentrations and higher coercivities are still identified at 0 45 0 6 1 5 1 7 2 9 3 1 4 4 4 7 5 3 5 7 5 9 6 1 and 8 2 8 4 ka these intervals are in phase within dating errors these intervals are in phase with weak summer monsoon events which indicate that a relationship between magnetic results and paleoclimatic events is partially preserved