the m 5 1 1980 arudy earthquake sequence western pyrenees france a revisited multi scale integrated seismologic geomorphologic and tectonic investigation this paper presents a combination of seismic imaging geomorphologic and tectonic data and an interpretation of the m 5 1 1980 arudy earthquake sequence putting in relation the seismicity the inherited faults and the geomorphologic wurm and postwurm markers in this region of the pyrenees since the anticlockwise rotation of the regional compression axis in oligocene time western pyrenees are under a dextral regime and the resulting motion is accommodated along major inherited e w dextral strike slip faults the arudy aftershocks sequence is controlled by antecedent horsetail splay faults built at the boundary between two shallow mesozoic crustal blocks most probably due to their differing rheology this boundary has played the role of a seismic barrier stopping the e w slip motion the arudy earthquake has reactivated the eastern segment of the main e w strike slip fault while the post seismic aftershocks correspond to local relaxation processes in normal tectonic behavior

environmental aspect of radon potential in terra rossa and eutric cambisol in slovenia terra rossa and eutric cambisol soils were surveyed in slovenia at both sites 6 13 boreholes were drilled in a regular 24 m 24 m square grid soil samples from various depths were taken for gamma spectrometric analysis and radon in soil gas was measured at a depth of 80 cm using an alphaguard instrument the following ranges of activity concentration bq kg 1 were obtained for 238u 226ra 228ra 40k and 137cs in terra rossa 64 74 70 84 45 49 293 345 20 30 and in eutric cambisol 55 80 132 147 50 57 473 529 106 272 radon activity concentrations in both soils ranged from about 100 kbq m 3 to 370 kbq m 3

soil gas survey for tracing seismogenic faults a case study in the fucino basin central italy soil gas he rn co2 and ch4 surveys were performed to test their sensitivity for locating fault or fracture systems when masked by unconsolidated lithologies and to investigate the gas bearing properties of seismogenic faults the fucino basin central italy was chosen as a test site because it displays a network of surface and shallow buried active faults within the valley floor which were partially reactivated during the 1915 avezzano earthquake ms 7 0 the highest radon values were found aligned along the most important faults especially along the san benedetto gioia dei marsi fault sbgmf to the east and in the northwestern sector where the avezzano celano fault acf meets the northwestern prolongation of the 1915 coseismic rupture moderately anomalous values of radon occur along the faults located in the depression of the historical lake trasacco fault tf and ortucchio fault of anomalous values of co2 rn and he were detected north of borgo ottomila in a zone where coseismic scarps and liquefaction phenomena were responsible for a pervasive brittle deformation during the 1915 earthquake highest helium values prevail in the western part of the plain in correspondence with a horst structure bounded by the tf and considered to be the extension of the vallelonga trasacco ridge results of this research confirm the possible usefulness of soil gas methods for locating some tectonic faults when covered by unconsolidated deposits the study provides some clues on the spatial influence of tectonics and geology on deeply seated gas migration toward the surface

radon in himalayan springs a geohydrological control this paper presents the results of radon measurements in springs of the himalayan region by using radon emanometry technique the radon was measured in different springs draining from different geohydrological setups and from stream water in order to find the geohydrological control over radon concentration in groundwater emanating in the form of spring the radon values were found to vary from 0 4 bq l to 887 bq l being observed lowest for a turbulent stream and highest for the spring the radon values were recorded highest in the springs draining through gneiss granite mylonite etc radon concentrations have been related with four spring types viz fracture joint related spring fault lineament related spring fluvial related spring and colluvial related spring showing geohydrological characteristics of the rocks through which they are emanating the high radon concentration in fracture joint and fault lineament spring is related to increased ratio of rock surface area to water volume and uranium mineralisation in the shear zones present in the close vicinity of fault and thrust the low concentration of radon in fluvial and colluvial springs is possibly because of high transmissivity and turbulent flow within such deposits leading to natural de emanation of gases

a two dimensional model simulation of the el chichon volcanic eruption cloud using a two dimensional model of sulfate photochemistry transport and aerosol microphysics we have simulated a 2 year period following the eruptions of el chichon our calculations suggest that the residence time of the cloud in the stratosphere exceeds 2 years the model reproduces the observed optical depth lidar backscatter and infrared extinction coefficients if about 10 megatonnes of so2 are injected the major deficiency of the model is a somewhat too rapid transport

mapping of sea ice production in the arctic coastal polynyas 1 high ice production in coastal polynyas over the continental shelves in the arctic ocean is responsible for the formation of cold saline water which contributes to the maintenance of the arctic ocean halocline the accurate detection of coastal polynyas including an estimate of thin ice thickness is essential for the estimation of sea ice production this paper presents an algorithm that estimates thin ice thickness using special sensor microwave imager ssm i data in the arctic ocean detection and estimation of sea ice thicknesses of 0 15 m are based on the ssm i 85 and 37 ghz polarization ratios pr85 and pr37 through a comparison with sea ice thicknesses estimated from the advanced very high resolution radiometer avhrr data in the three different arctic coastal polynyas thus for the entire arctic ocean the algorithm can be used for the detection of coastal polynyas and for the estimation of sea ice production through combination with heat flux calculation this study provides the first circumpolar mapping of sea ice production in coastal polynyas over the entire arctic ocean high ice production is confined to the major arctic coastal polynyas with the highest ice production rate being in the north water polynya this study also presents the interannual variability of sea ice production in the 10 major coastal polynyas from 1992 to 2007 in general interannual variability in sea ice production has good correlation with polynya extent rather than surface air temperature the mapping also provides surface heat and salt flux conditions in the ice covered region which have not been well understood to date

spatial and temporal anomalies of soil gas in northern taiwan and its tectonic and seismic implications abstract in this paper we study 1 the spatial anomalies and 2 the temporal anomalies of soil gas in northern taiwan the spatial anomalies of soil gas are related to tectonic faults while the temporal anomalies of soil gas are associated with pre earthquake activities detailed soil gas sampling was systematically performed and the analysis of the collected gas species shows that high helium and nitrogen concentrations appear in samples from specific sites which coincide with the structural setting of the area studied this analysis indicates the possibility of using these soil gases to determine fault zones in the studied area based on the soil gas data a station tapingti for automatic soil gas monitoring was constructed on an appropriate site at the fault zone some anomalous high radon concentrations at certain times can be identified from the dataset which was generated by the continuous monitoring of soil gas for over a year notably many of these anomalies were observed several hours to a few days before the earthquakes ml 3 that occurred in northern taiwan by combining the information of epicenters and fault plane solutions of these earthquakes we find that the shallow earthquakes 20 km were mainly thrust type earthquakes and distributed in greater distances 45 km east of the monitoring site group b such focal mechanisms of earthquakes suggest an extensional and compressional structural domain in the continental crust for group a and group b earthquakes respectively it is suggested that the pre earthquake activities associated with the seismicity of group b may be transmitted along the major decollement in the region below the tapingti station leading to the observed soil gas enhancements

helicopter borne observations with portable microwave radiometer in the southern ocean and the sea of okhotsk accurately measuring and monitoring the thickness distribution of thin ice is crucial for accurate estimation of ocean atmosphere heat fluxes and rates of ice production and salt flux in ice affected oceans here we present results from helicopter borne brightness temperature tb measurements in the southern ocean in october 2012 and in the sea of okhotsk in february 2009 carried out with a portable passive microwave pmw radiometer operating at a frequency of 36 ghz the goal of these measurements is to aid evaluation of a satellite thin ice thickness algorithm which uses data from the spaceborne advanced microwave scanning radiometer earth observing system amsr e or the advanced microwave scanning radiometer ii amsr ii amsr e and amsr ii tb agree with the spatially collocated mean tb from the helicopter borne measurements within the radiometers precision in the sea of okhotsk in february 2009 the amsr e 36ghz tb values are closer to the mean than the modal tb values measured by the helicopter borne radiometer in an antarctic coastal polynya in october 2012 the polarization ratio of 36ghz vertical and horizontal tb is estimated to be 0 137 on average our measurements of the tb at 36ghz over an iceberg tongue suggest a way to discriminate it from sea ice by its unique pmw signature

radon groundwater monitoring at underground laboratories of gran sasso italy an automatic multiparametric equipment groundwater temperature electrical conductivity ph 222rn has been planned and realized to study the correlations between the variations of radon with the strain processes of the rock and transport properties related to the groundwater geochemistry the monitoring activity at underground laboratories of gran sasso with a groundwater sampling period of twelve hours has been started from may 1996 from geochemical data recorded during the first year a high dynamic behaviour of shallow aquifer has been emphasized due to high permeability of the cretaceous limestones that form part of the gran sasso massif also the residual time series analysis of the geochemical parameters has emphasized pre co seismic anomalies in electrical conductivity and post seismic in radon content in groundwater related to local seismicity

polynya dynamics a review of observations and modeling 1 polynyas are nonlinear shaped openings within the ice cover ranging in size from 10 to 105 km2 polynyas play an important climatic role first winter polynyas tend to warm the atmosphere thus affecting atmospheric mesoscale motions second ocean surface cooling and brine rejection during sea ice growth in polynyas lead to vertical mixing and convection contributing to the transformation of intermediate and deep waters in the global ocean and the maintenance of the oceanic overturning circulation since 1990 there has been an upsurge in polynya observations and theoretical models for polynya formation and their impact on the biogeochemistry of the polar seas this article reviews polynya research carried out in the last 2 decades focusing on presenting a state of the art picture of the physical interactions between polynyas and the atmosphere sea ice ocean system observational and modeling studies the surface heat budget and water mass transformation within these features are addressed

thickness distribution texture and stratigraphy and a simple probabilistic model for dynamical thickening of sea ice in the southern sea of okhotsk 1 sea ice thickness data and sea ice samples were analyzed to examine the characteristics of the ice thickness distribution and ice texture and to understand ice growth processes in the southern sea of okhotsk ice thickness data and samples were obtained aboard the icebreaker soya in early february the ice growth season ice thickness data which were obtained with a video monitoring system installed on the side deck of the ship each winter from 1991 to 2000 except 1995 show that the average thickness ranges from 19 7 to 55 23 cm and that it matches the characteristics of a poisson distribution ice structure analysis reveals that granular texture occupies about three quarters of the total ice thickness and that the ice exhibits a layered structure with unit thickness averaging 5 to 10 cm stratigraphy and stable isotopic composition of the ice indicate that snow ice accounts for 10 and frazil ice accounts for 64 of the total ice thickness this suggests that dynamic ice thickening processes such as frazil ice growth and piling up are more significant than congelation growth on the basis of these characteristics which resemble more those of antarctic than arctic sea ice we propose a conceptual model for the ice thickening process in this region it is shown that this model can explain the shape of the ice thickness distribution well and is analogous with the concept of the pancake cycle and multiple rafting of antarctic sea ice growth and thickening

identifying an asperity through 3 d mapping of the frequency magnitude distribution following the idea introduced by wiemer and wyss 1997 here is an attempt to map the seismic hazard in terms of the b value in the frequency magnitude distribution in a region with moderate seismic activity bearn region french pyrenees in this area the complexity of the geology makes it necessary to perform a 3 d mapping b values are computed within 5 km radius spherical volumes that contain an average of 140 events strong lateral variations between 0 45 and 1 8 are observed at short scales in the whole investigated volume the minimum of the b value is clearly correlated with a historically active zone which last ruptured in 1980 mb 5 1 interpretating low b values in terms of high stresses may lead us to consider this minimum b patch as a 5 km radius asperity this study allows to define its location and dimensions

natural radioactivity levels k th u and rn in the cecita lake area sila massif calabria southern italy an attempt to discover correlations with soil features on a statistical base soils can exhibit a complex range of physical mineralogical and chemical features depending on many interrelated factors such as parental rock composition and mineralogy climate topography vegetation amounts and types water infiltration versus runoff soil moisture organic matter presence and types of anthropogenic contaminants and many others radioactivity as measured on these complex systems is consequently perturbed by several mixed effects in order to find out a possible potential relationship among soil properties and experimental data attributable to radioactivities of k th u and rn a detailed investigation has been performed in the cecita lake basin sila grande calabria southern italy most of the soil types outcropping in the cecita lake surroundings belong to the entisol and inceptisol orders usda united states department of agriculture 2006 keys to soil taxonomy 10th edit usda soil survey staff natural resources conservation service washington d c 333 pp representing relatively young poorly to moderately differentiated soils showing features strongly dependent on the nature of the parent rock and the climatic conditions disintegrations contributed by k th u and rn measured respectively in k ppm u and th and kbq m3 rn have been related to 13 a priori known soil unit groups with well defined general features and spatial position the data have been analysed by using graphical and numerical statistical procedures able to manage compositional data in a correct sample space the paper summarises the results of this research and highlights the conclusions drawn from these investigations particularly concerning i the modelling of the high u variability a behaviour that tends to homogenise the differences potentially attributable to soil features with the exception of situations where uranium could be enriched due to adsorption onto iron oxi hydroxides and or clay minerals or concentrated in argillic horizons due to illuviation ii the discovering of the discriminative effect of the k th ratio values particularly for soil groups where th behaviour as other tetravalent actinides is strongly affected by the presence of mineral colloids or where the presence of clays affects the trapping of k iii the clustering of the a priori known soil groups in four new sets characterised by internal similarities for rn values for which the morphology appears to be the most important discriminative effect

el chichon the genesis of volcanic sulfur dioxide monitoring from space the 1982 eruption of el chichon inspired a new technique for monitoring volcanic clouds data from the total ozone mapping spectrometer toms instrument on the nimbus 7 satellite were used to measure sulfur dioxide in addition to ozone for the first time precise data on the sulfur dioxide mass in even the largest explosive eruption plumes could be determined the plumes could be tracked globally as they are carried by winds magmatic eruptions could be discriminated from phreatic eruptions the data from el chichon are reanalyzed in this paper using the latest version of the toms instrument calibration v8 they show the shearing of the eruption cloud into a globe circling band while still anchored over mexico in three weeks the measured sulfur dioxide mass in the initial march 28 eruption was 1 6 tg the april 3 eruption produced 0 3 tg more and the april 4 eruptions added 5 6 tg for a cumulative total of 7 5 tg in substantial agreement with estimates from prior data versions toms aerosol index absorbing aerosol data show rapid fallout of dense ash east and south of the volcano in agreement with advanced very high resolution radiometer avhrr ash cloud positions

study of soil gas radon variations in the tectonically active dharamshala and chamba regions himachal pradesh india soil gas radon measurements were made in chamba and dharamshala regions of himachal pradesh india to study the correlation if any between the soil gas radon radium activity concentration of soil and the geology active tectonics of the study region soil gas radon surveys were conducted around the local fault zones to check their tectonic activities using the soil gas technique soil gas radon activity concentration at thirty five different locations in dharamshala region has been found to be varying from 13 2 1 5 to 110 8 5 0 kbq m 3 with a geometrical mean of 35 9 kbq m 3 and geometrical standard deviation of 1 8 radon activity concentration observed in the thirty seven soil gas samples collected from the chamba region of himachal pradesh varies from 5 2 1 0 to 35 6 2 5 kbq m 3 with geometrical mean of 15 8 kbq m 3 and geometrical standard deviation of 1 6 average radium activity concentrations in thirty four soil samples collected from different geological formations of dharamshala region and chamba region are found to be 40 4 17 and 38 6 1 7 bq kg 1 respectively it has been observed that soil gas radon activity concentration has a wide range of variation in both dharamshala and chamba regions while radium activity concentrations in soil samples are more or less same in both the regions moreover soil gas radon activity concentration has a better positive correlation with the radium activity concentration in soil samples collected from chamba region as compared to dharamshala region

flux chamber measurements of anomalous co2 emission from the flanks of mammoth mountain california the co2 fluxes involved in the mass mortality of large stands of timber on the flanks of mammoth mountain in california s sierra nevada were measured and spatial and temporal inhomogeneities observed our estimate of the integrated flux over the total area of tree kill is on the order of 400 t day 1 small scale spatial variability most likely reflects varying degrees of shallow bedrock fracture and soil compaction temporal variability suggests a fast response to subsurface conditions such as seismically induced crack propagation degassing of intruded magma or changing groundwater soil moisture conditions

continuous monitoring of distal gas emanations at vulcano southern italy the increasing activity of vulcano island italy since 1985 led to the initiation of continuous geochemical monitoring of the lateral soil gas emissions on the basis both of their relative geochemical characteristics and of local considerations three gaseous components were selected for monitoring namely co2 he and 222rn monitoring has been performed by means of specific analysers gases extracted from a water well located at the foot of the active cone were selected for monitoring on the basis of their geochemical and isotopic characters that indicate their genetic link with central high temperature fumarolic gases emitted at the crater very strong variations of gas composition can be observed within one day from 1 to about 94 for co2 some variations display a daily character and can be correlated with that of atmospheric pressure the three monitored gases are highly correlated suggesting very high kinetics of gas transfer in the system because of these considerable variations of chemical composition bulk concentrations obviously are not suitable for monitoring at vulcano however the evolution with time of ratios such as 222rn co2 and he co2 the latter being corrected for atmospheric contamination supplies numerical parameters that the expected to characterize the intensity of the degassing process a new input of magmatic gases that would lead to an increase in the 222rn co2 and he co2 ratios should therefore be detected by such a monitoring station

on the trigger of el nino southern oscillation by the forcing of early el chichon volcanic aerosols after the volcanic eruption of el chichon in 1982 the distribution of volcanic aerosols in the upper atmosphere was zonally very inhomogeneous for about a month or more and was located in a fairly uniform zonal band around the earth in the northern subtropical region for the ensuing several months the impact of those aerosols absorbing radiation on the atmospheric motion is discussed in the model of gill 1980 it is shown that the mean westerly wind induced near the central pacific equatorial region would be able to trigger or amplify the el nino southern oscillation several observed results related to the simulation are discussed in some detail the location of the initial center of most aerosols relative to the central pacific is important in the model and the impact of the forcing at the agung event of 1963 is estimated to be smaller than that of the present event which seems to agree with observed results

soil gas geochemistry in relation to eruptive fissures on timanfaya volcano lanzarote island canary islands spain abstract we report herein the first results of an extensive soil gas survey performed on timanfaya volcano on may 2011 soil gas composition at timanfaya volcano indicates a main atmospheric source slightly enriched in co2 and he soil co2 concentration showed a very slight deep contribution of the timanfaya volcanic system with no clear relation to the main eruptive fissures of the studied area the existence of soil helium enrichments in timanfaya indicates a shallow degassing of crustal helium and other possible deeper sources probably form cooling magma bodies at depth the main soil helium enrichments were observed in good agreement with the main eruptive fissures of the 1730 36 eruption with the highest values located at those areas with a higher density of recent eruptive centers indicating an important structural control for the leakage of helium at timanfaya volcano atmospheric air slightly polluted by deep seated helium emissions co2 degassed from a cooling magma body and biogenic co2 might be the most plausible explanation for the existence of soil gas helium is a deep seated gas exhibiting important emission rates along the main eruptive fissure of the 1730 36 eruption of timanfaya volcano

compositions and flux of soil gas in liu huang ku hydrothermal area northern taiwan abstract soil co 2 flux has been considered a useful proxy to remotely monitor volcanic activity in a hydrothermal area within a safe distance the liu huang ku lhk area which is close to the taipei basin and many existing active fumaroles and hot springs was chosen for the first systematic soil gas study in a hydrothermal area of taiwan in 2004 and 2006 the soil co 2 flux was measured by the closed chamber method with a non dispersive infrared detector soil co 2 emission rate was estimated 19 8 0 2 t day 1 and 582 t km 2 day 1 in 2004 and 22 4 0 2 t day 1 and 659 t km 2 day 1 in 2006 respectively these values are close to those reported for other active high co 2 flux hydrothermal areas of the world it implies that magmatic gases are actively degassing from subsurface in northern taiwan helium and carbon isotopic data reveal that soil gas in lhk is mainly derived from the mantle and is mixed with a small amount of crustal and air components the abundance of soil co 2 shows a positive correlation with the 3 he 4 he ratios and total sulfur contents which are considered as magmatic sensitive indicators for the fumarolic samples therefore soil co 2 could be used as a good proxy for future monitoring of magmatic activity in this area

precursory subsurface 222rn and 220rn degassing signatures of the 2004 seismic crisis at tenerife canary islands precursory geochemical signatures of radon degassing in the subsurface of the tenerife island were observed several months prior to the recent 2004 seismic volcanic crisis these premonitory signatures were detected by means of a continuous monitoring of 222rn and 220rn activity from a bubbling co2 rich gas spot located at 2 850 m depth inside a horizontal gallery for groundwater exploitation at tenerife multivariate regression analysis mra on time series of the radon activity was applied to eliminate the radon activity fluctuation due to external variables such as barometric pressure temperature and relative humidity as well as power supply material failure forecast method ffm was successfully applied to forecast the anomalous seismicity registered in tenerife island in 2004 the changes in the 222rn 220rn ratio observed after the period of anomalous seismicity might suggest a higher gas flow rate and or changes in the vertical permeability induced by seismic activity

soil co2 flux in hydrothermal areas of the tatun volcano group northern taiwan abstract we measured soil co2 flux in the representative hydrothermal areas of the tatun volcano group tvg to better understand the volcano s dynamic nature and to estimate its soil co2 degassing output results show that the average soil co2 fluxes obtained at da you keng dyk geng tze ping gtp she haung ping shp and tatun natural park tnp were 128 g m 2 d 1 518 g m 2 d 1 420 g m 2 d 1 and 25 g m 2 d 1 respectively the range is comparable to other active volcanic hydrothermal areas in the world along with liu huang ku lhk where the soil co2 flux is known the total soil co2 output from measured areas is evaluated at 82 t d 1 furthermore a first total soil co2 output from the whole hydrothermal areas of the tvg is roughly estimated at 113 t d 1 which includes 15 t d 1 mantle contribution considering the mantle derived co2 flux and h2o co2 ratio of fumarolic gas thermal energy associated with the diffuse degassing at the tvg hydrothermal area is estimated at 8 2 mw carbon 13c and helium 3he 4he isotopic ratios of soil samples of the studied areas ranged from 4 4 to 6 7 and 2 45 to 6 98 ra respectively the extent of air involvement in the soil degassing system as constrained by the helium and carbon isotopic compositions provides essential information for depicting regional degassing features of the hydrothermal areas

estimation of thin sea ice thickness from noaa avhrr data in a polynya off the wilkes land coast east antarctica antarctic coastal polynyas are major areas of intense ocean atmosphere heat and moisture flux and associated high sea ice production and dense water formation their accurate detection including an estimate of thin ice thickness is therefore very important in this paper we apply a technique originally developed in the arctic to an estimation of sea ice thickness using us national oceanic and atmospheric administration noaa advanced very high resolution radiometer avhrr data and meteorological data in the vincennes bay polynya off wilkes land east antarctica the method is based upon the heat flux calculation using sea ice surface temperature estimates from the satellite thermal infrared data combined with global objective analysis european centre for medium range weather forecasts ecmwf data the validity of this method is assessed by comparing results with independent ice surface temperature and ice thickness data obtained during an australian led research cruise to the region in 2003 in thin ice polynya regions ice thicknesses estimated by the heat flux calculation using avhrr and ecmwf data show reasonable agreement with those estimated by a applying the heat flux calculation to in situ radiation thermometer and meteorological data and b in situ observations the standard deviation of the difference between the avhrr derived and in situ data is 0 02 m comparison of the avhrr ice thickness retrievals with coincident satellite passive microwave polarization ratio data confirms the potential of the latter as a means of deriving maps of thin sea ice thickness on the wider scale uninterrupted by darkness and cloud cover

soil co2 flux baseline in an urban monogenetic volcanic field the auckland volcanic field new zealand the auckland volcanic field avf is a dormant monogenetic basaltic field located in auckland new zealand though soil gas co2 fluxes are routinely used to monitor volcanic regions there have been no published studies of soil co2 flux or soil gas co2 concentrations in the avf to date or many other monogenetic fields worldwide we measured soil gas co2 fluxes and soil gas co2 concentrations in 2010 and 2012 in varying settings seasons and times of day to establish a baseline soil co2 flux and to determine the major sources of and controlling influences on auckland s soil co2 flux soil co2 flux measurements varied from 0 to 203 g m 2 day 1 with an average of 27 1 g m 2 day 1 higher fluxes were attributed to varying land use properties e g landfill using a graphical statistical approach two populations of co2 fluxes were identified isotope analyses of 13co2 confirmed that the source of co2 in the avf is biogenic with no volcanic component these data may be used to assist with eruption forecasting in the event of precursory activity in the avf and highlight the importance of knowing land use history when assessing soil gas co2 fluxes in urban environments

nitrogen as the carrier gas for helium emission along an active fault in nw taiwan variations of he gas concentration are widely applied in studies devoted to the location of faults and to monitor seismic activities up to now its migration mechanism in soil is not fully understood a systematic soil gas survey across an active fault in nw taiwan provides the opportunity to closely examine the mechanism of he migration in the fault zone significant spatial and temporal correlations observed between soil n2 and he gas support the hypothesis that n2 is the probable carrier gas for he emission in the studied area based on n2 ar ratios and n2 isotopic results the excess soil n2 in this study is considered to be largely derived from ancient atmospheric air which was dissolved in groundwater furthermore observations rule out the possibility of co2 being the dominant carrier gas for he in the studied area based on the c and he isotopic compositions and the relationship between concentrations of these gases at least two soil gas sources a and b can be identified in the studied area source a is an abiogenic gas source characterized by excess n2 and he and very low o2 and co2 content source b on the other hand is a mixture of biogenic gas and atmospheric air the development of the fault system is an important factor affecting the degree of mixture between sources a and b therefore variations of soil gas composition in particular those derived from source a could be a useful proxy for tracing faults in the area

estimation of the thin ice thickness and heat flux for the chukchi sea alaskan coast polynya from special sensor microwave imager data 1990 2001 1 one of the largest arctic polynyas occurs along the alaskan coast of the chukchi sea between cape lisburne and point barrow for this polynya a new thin ice thickness algorithm is described that uses the ratio of the vertically and horizontally polarized special sensor microwave imager ssm i 37 ghz channels to retrieve the distribution of thicknesses and heat fluxes at a 25 km resolution comparison with clear sky advanced very high resolution radiometer data shows that the ssm i thicknesses and heat fluxes are valid for ice thicknesses less than 10 20 cm and comparison with several synthetic aperture radar sar images shows that the 10 cm ice ssm i ice thickness contour approximately follows the sar polynya edge for the twelve winters of 1990 2001 the ice thicknesses and heat fluxes within the polynya are estimated from daily ssm i data then compared with field data and with estimates from other investigations the results show the following first our calculated heat losses are consistent with 2 years of over winter salinity and temperature field data second comparison with other numerical and satellite estimates of the ice production shows that although our ice production per unit area is smaller our polynya areas are larger so that our ice production estimates are of the same order because our salinity forcing occurs over a larger area than in the other models the oceanic response associated with our forcing will be modified index terms 4540 oceanography physical ice mechanics and air sea ice exchange processes 3360 meteorology and atmospheric dynamics remote sensing 4504 oceanography physical air sea interactions 0312 4572 oceanography physical upper ocean processes 4207 oceanography general arctic and antarctic oceanography keywords chukchi sea coastal polynya remote sensing

multivariate analysis of co2 h2s and ch4 diffuse degassing and correlation with fault systems in agua caliente tzitzio michoacan mexico abstract the quantitative relationships between soil gas flux anomalies and faults systems in agua caliente tzitzio geothermal system were analyzed statistically the main degassing features are related with thermal springs the data used in the multivariate analysis are geothermal gas fluxes and spatial structural data i e local fault strike exploratory data analysis eda and multivariate analysis of variance manova were implemented for the first time to statistically describe the relation between the location of degassing features and the presence of some local fault systems discriminating the direction of the main discharge channels and pointing to higher permeability faults the results show that there is a statistically significant correlation between diffuse degassing of co2 and ch4 and the n s and e w fault systems conversely h2s degassing does not show any correlation with the fault systems which may be related with the higher h2s reactivity compared with that of co2 and ch4 it is highly recommended to use eda and manova techniques in order to establish the main degassing directions in geothermal and volcanic areas

identification of latent faults using a radon test abstract this paper discusses the use of 222rn concentrations in water of natural springs as a geomorphological method to identify latent faults in low mid term activity areas the identification of this type of active fault may be crucial in hazard analysis structural geomorphology and in landscape evolution analysis the test used to identify these faults is based on the measuring of 222rn concentrations in water of springs linked to faults and comparison with those obtained from springs which although exactly the same lithological context are not linked with faults reference values if the difference between the measured value and the reference value is positive then an anomaly is identified and that measurement indicates a spring linked to a latent fault the test was applied and validated in springs linked to faults with a latent behaviour in cantabria northern spain these faults have shown an intermittent movement over the last 50 000 years and have contributed towards landslide processes playing a significant role in landscape evolution of the area

soil gases and sar measurements reveal hidden faults on the sliding flank of mt etna italy abstract from october 2008 to november 2009 soil co 2 radon and structural field surveys were performed on mt etna in order to acquire insights into active tectonic structures in a densely populated sector of the south eastern flank of the volcano which is involved in the flank dynamics as highlighted by satellite data insar the studied area extends about 150 km 2 in a sector of the volcano where insar results detected several lineaments that were not well defined from previous geological surveys in order to validate and better constrain these features with ground data evidences soil co 2 and soil radon measurements were performed along transects roughly orthogonal to the newly detected faults with measurement points spaced about 100 m in each transect the highest co 2 values were found very close to the lineaments evidenced by insar observations anomalous soil co 2 and radon values were also measured at old eruptive fractures in some portions of the investigated area soil gas anomalies were rather broad over transects probably suggesting a complex structural framework consisting of several parallel volcano tectonic structures instead of a single one soil gas measurements proved particularly useful in areas at higher altitude on mt etna i e above 900 m asl where insar results are not very informative are fairly limited and allowed recognizing the prolongation of some tectonic lineaments towards the summit of the volcano at a lower altitude on the volcanic edifice soil gas anomalies define the active structures indicated by insar results prominently down to almost the coastline and through the northern periphery of the city of catania coupling insar with soil gas prospecting methods has thus proved to be a powerful tool in detecting hidden active structures that do not show significant field evidences

tectonic and geologic influences on soil gas radon emission along the western extension of damascus fault syria the main purpose of this work is to demonstrate the possibility of using soil gas radon survey as a promising technique for locating the trend of western extension of damascus fault where it is hidden under a cover of pliocene unconsolidated deposits the normal level of radon background was established in a stationary area away from the tectonic influence of the fault zone the sites of radon measurements were chosen according to the accessibility and suitability of the area besides some indicative geologic and tectonic evidences a total of 81 radon sampling points were analyzed and the results revealed some reasonable spatial increases with peak values of 2 3 times higher than the background level trending in accordance with what is believed to be the general direction of the fault in the bedrock however permeability properties rather than geotectonic activities seemed to be the main causes controlling the variations of radon concentration over the concerned fault zone yet the moderate level of the observed radon values could be attributed to the nature of the prevailing rock types as well as the probable effect of locked tectonic structure due to the action of high regional compressive regime which typically originates such reverse faulting further the accumulation of fill materials due to rock alteration along the plane of such dormant fault through long geologic time possibly led to increase in the ratio of clay minerals which may affect soil gas mobility through the medium

geochemical characteristics of soil radon and carbon dioxide within the dead sea fault and karasu fault in the amik basin hatay turkey abstract the study area is close to the boundary of three tectonic plates anatolian arabian and african plates and is characterized by important tectonic lineaments which consist mainly of the dead sea fault dsf the karasu fault and the east anatolian fault eaf systems to understand the origin of soil gas emanation and its relationships with the tectonics of the amik basin hatay a detailed soil gas sampling was systematically performed together with co2 flux measurements 220 soil gas samples were analyzed for rn and co2 concentrations the distribution of soil rn kbq m3 co2 concentration ppm and co2 flux g m2 day in the area appears as a point source spot and or diffuses halo anomalies along the buried faults fractures due to crustal leaks the results revealed that rn and co2 concentrations in the soil gas show anomalous values at the specific positions in the amik basin the trace of these anomalous values is coincident with the n s trending dsf co2 is believed to act as a carrier for rn gas based on the rn and co2 concentrations of soil gases at least three gas components are required to explain the observed variations in addition to the atmospheric component two other gas sources can be recognized one is the deep crust component which exhibits high rn and co2 concentrations and is considered the best indicator for the surface location of fault fracture zones in the region the other component is a shallower gas source with high rn concentration and low co2 concentration moreover he isotopic compositions of representative samples vary from 0 94 to 0 99 ra illustrating that most samples have a soil air component and may have mixed with some crustal component without significant input of the mantle component based on the repeated measurements at a few sites soil gas concentrations at the same site were observed to be higher in 2014 than in 2013 which may be associated with the activity of the dsf in 2013 2014 this suggests that soil gas variations at fault zone are closely related to the local crustal stress and hence are suitable for monitoring fault activities

impact of geohydrology and neotectonic activity on radon concentration in groundwater of intermontane doon valley outer himalaya india radon concentration was measured in 133 water samples from tubewells handpumps dug wells and springs of the doon valley outer himalaya india the observed radon values were found to vary from 10 to 154 bq l whereas radium in selected water samples varied from 0 11 to 0 75 bq l three different clusters of high radon values were observed in the north western central and south eastern parts of the doon valley these clusters were found to be associated with tectonics thrust fault and associated uranium mineralization in the area in general radon concentration in groundwater was found to be positively correlated with the depth of the wells whereas no significant correlation was observed between radon concentration in groundwater and the water temperature ph value conductivity and altitude of the water samples an attempt has also been made to determine the nature and extent of aquifers in the doon valley on radon concentration in groundwater the variation in radon concentration within the groundwater of the study area was found to be controlled by the neotectonic activity and geohydrological processes that occur in the area the impact of these activities on radon concentration in groundwater are discussed

intraplate seismicity new seismotectonic data in western europe abstract fault plane solutions for 128 earthquakes which occurred in france and neighbouring areas have been determined stress field information given by these data are discussed in relation to previous tectonic knowledge the western alps are characterized by a compressional regime with a fan shaped distribution of p axes which might be related to the interaction mechanism between europe and the adriatic plate the pyrenean region is mainly submitted to a south north compression tectonic activity in this area seems to be determined by the presence of two subduction zones with reverse dips in the south bay of biscay and in the central pyrenees the transition zone between these two active belts is characterized by significant seismicity with a transpression regime

investigations of newly formed sea ice in the cape bathurst polynya 2 microwave emission 1 this study examines the role of newly formed sea ice geophysical state on microwave emission coincident with sea ice geophysical sampling ship based passive microwave emission data dual polarized at 19 37 and 85 ghz were collected in the cape bathurst polynya during 18 october and 13 november 2003 using polarization ratios prs we found that bare thin ice was separable from snow covered ice thin snow equal to 0 02 0 13 m thickness is significantly correlated with the spectral gradient ratios grv 85 19 r2 0 55 p value 0 2 the relationship between atmospherically corrected r37 and bare ice thickness showed an exponential relationship very comparable to that reported by martin et al 2004 which is ascribed to the reduction of bare ice surface salinity based on both observational and modeling studies however the relationship quickly becomes invalid for even thin snow covered ice due to significant impact of thin wet liquid water fraction 0 02 0 04 snow on microwave emission our results suggest that the sea ice algorithms nasa team and nasa team 2 could underestimate total ice concentration over thin bare ice by 35 on average while both algorithms underestimate the total ice concentration by 20 over snow covered ice using pr 85 sea ice could be delineated from open water using a properly adjusted threshold value accounting for cloud or fog effects possibly with the exception of dark nilas and or bare consolidated pancakes

gas geochemistry and seismotectonics a review abstract publications on soil and spring gases have been examined regarding their relationships with both tectonic and seismic activities the main sources behaviours and uses of species detected in soils and springs are displayed and their mode of sampling and analysing briefly described the main patterns of degassing in soils are described and we outline the wide range of geochemical signatures as the result of both permeability and mineralogical contrasts because thermomineral waters have been in contact with great volumes of crustal rocks at various depths spring gases might be more representative of the local environment than soil gases moreover gas signature comparisons show that spring gases are much more enriched with deep gases and slightly contaminated by atmospheric gases therefore they can be considered as better samples for identifying precursors of earthquakes environmental perturbations are examined and it is shown from divergent cases that pressure temperature soil moisture or earth tides may generate very high perturbations of the degassing process such effects demonstrate that no systematic correction law can be proposed and that removing external contributions from gas concentrations must be performed case by case this demonstrates therefore the need for the simultaneous measurement of external parameters during gas monitoring a qualitative examination of about 150 claimed precursors proposed in the literature has been reviewed as noted by previous authors anomalies appear at distances sometimes much greater than typical source dimensions and occur in the field of strain higher than 10 9 most of them being in the field of strain higher than 10 8 taking into account the very high heterogeneity of such a set of data we can suggest that amplitudes of gas anomalies are independent of both magnitudes and epicentral distances of related earthquakes suggesting local conditions to control amplitudes on the contrary precursory time and duration of anomalies seem to increase both with magnitudes and epicentral distances abundant evidence demonstrates the major role of crustal fluids in the earthquake cycle many works have outlined the fact that crustal instabilities can appear as the result of low stress strain perturbations during loading it has been suggested that motion of fluids may occur at various scales from microcrack fluid transfer up to changes of hydraulic levels of water tables the study of subsequent anomalies is expected to supply a tool for earthquake prediction following previous authors we outline the need for further methodological improvements including the setting up of multiparameter station networks and the simultaneous recording of the main external parameters atmospheric pressure water and air temperature soil moisture for signal processing

anomalies of mantle derived helium during the 1997 1998 seismic swarm of umbria marche italy more than 100 he 4he isotope ratios were measured in co2 dominated gas samples collected during the 1997 1998 seismic crisis that shook the umbria marche central apennines italy although the gas emissions were located in a typical crustal environment the measured values delineate variable mixing proportions between mantle derived and crustal helium during the monitoring period anomalous he 4he ratios were observed together with a significant increase of fluid outflows the observed he 4he anomalies appear to be driven by stress induced crustal deformations affecting micro fracturing and bulk permeability and in turn by a seismogenic induced modification of the crustal permeability of rocks since crustal deformations can also occur aseismically the geochemical anomalies must be considered indicators of processes occurring below the surface which could eventually help to estimate the probability increase of an impending earthquake instead of pure empirical precursors

integrated geophysics and soil gas profiles as a tool to characterize active faults the amer fault example pyrenees ne spain the combined use of geophysical and soil gas composition exploration methods allows to rapidly obtain at relative low cost information that might be related to seismic activity conditions in this study we carried out geochemical soil gas sampling 222rn 220rn and co2 electrical resistivity tomography and seismic refraction profiles in two selected zones near the town of amer in the spanish pyrenees where the presence of recent fractures is evident in the field data analysis clearly reveals anomalous values for each gas at specific positions along the electrical imaging transects geomorphologic and hydrogeologic data and the integration of geophysical data and soil gas measurements indicate that 1 endogene gases radon 222rn and carbon dioxide co2 are released from the meta sedimentary basement rocks across the main fractured zones with higher permeability values while lower cenozoic detrital sedimentary formations act as an impervious boundary 2 sites with highest radon concentrations 52 kbq m 3 coincide with the zones in the amer fault showing more recent geomorphic evidence of activity and more specifically with those areas covered by thinner surficial formations 3 the lowest 222rn values 0 2 0 4 kbq m 3 were recorded just on the master active fault plane this pattern could be explained by a dilution effect resulting from high rates of soil co2 efflux 267 g m 2 day 1 4 soil thoron 220rn activity is maximum 143 kbq m 3 in areas with high surficial fracturing 5 groundwater pumping may cause important distortions in the natural flow dynamics and in the measured concentrations of gases the agreement between the different data geochemical geophysical and hydrogeological and field observations geology and geomorphology leads us to propose a preliminary tectonic gravitational model for the study area

thickness and production of sea ice in the okhotsk sea coastal polynyas from amsr e 1 from comparisons with thickness of sea ice from advanced very high resolution radiometer avhrr and ice profiling sonar data we have developed an advanced microwave scanning radiometer eos amsr e thin ice thickness algorithm for the sea of okhotsk this algorithm can estimate ice thickness of 0 2 m without snow using the polarization ratio of amsr e brightness temperature at a 36 5 ghz channel from a linear relationship with avhrr ice thickness when a snow cover exists on the thin ice surface as occurred a few times in each winter it is shown that the algorithm cannot detect the thin ice sea ice and dense shelf water dsw production in coastal polynya are estimated on the basis of heat flux calculation with the daily amsr e ice thickness for three winters december march of 2002 2003 to 2004 2005 the ice production is largest in the northwest shelf nws polynya which accounts for 45 of the sum of ice production in major coastal polynyas the ice production in major coastal polynyas would cover the maximum ice area of the okhotsk sea if the average ice thickness is assumed to be 1 m variability of the ice production is mainly modulated by air temperature in the nws polynya which is the main dsw production area the annual dsw formation rate is estimated to be 0 36 sv

insights into fluid circulation across the pernicana fault mt etna italy and implications for flank instability article i nfo we conducted geophysical geochemical measurements on a 2k m n s profile cutting across the pernicana fault one of the most active tectonic features on the ne flank of mt etna the profile passes from the unstable e flank of the volcano to the south to the stable n flank and significant fluctuations in electrical resistivity self potential and soil gas emissions co2 rn and th are found the detailed multidisciplinary analysis reveals a complex interplay between the structural setting uprising hydrothermal fluids meteoric fluids percolating downwards ground permeability and surface topography in particular the recovered fluid circulation model highlights that the southern sector is heavily fractured and faulted allowing the formation of convective hydrothermal cells although the existence of a hydrothermal system in a volcanic area does not surprise these results have great implications in terms of flank dynamics at mt etna indeed the hydrothermal activity interacting with the pernicana fault activity could enhance the flank instability our approach should be further extended along the full extent of the boundary between the stable and unstable sectors of etna for a better evaluation of the geohazard in this active tectonic area

structure and co2 budget of merapi volcano during inter eruptive periods soil temperature and gas co2 concentration and flux have been investigated at merapi volcano indonesia during two inter eruptive periods 2002 and 2007 precise imaging of the summit crater and the spatial pattern of diffuse degassing along a gas traverse on the southern slope are interpreted in terms of summit structure and major caldera organization the summit area is characterized by decreasing co2 concentrations with distance from the 1932 crater rim down to atmospheric levels at the base of the terminal cone similar patterns are measured on any transect down the slopes of the cone the spatial distribution of soil gas anomalies suggests that soil degassing is controlled by structures identified as concentric historical caldera rims 1932 1872 and 1768 which have undergone severe hydrothermal self sealing processes that dramatically lower the permeability and porosity of soils temperature and co2 flux measurements in soils near the dome display heterogeneous distributions which are consistent with a fracture network identified by previous geophysical studies these data support the idea that the summit is made of isolated and mobile blocks whose boundaries are either sealed by depositional processes or used as pathways for significant soil degassing within this context self sealing both prevents long distance soil degassing and controls heat and volatile transfers near the dome a rough estimate of the co2 output through soils near the dome is 200 230 t day 1 i e 50 of the estimated total gas output from the volcano summit during these quiescent periods on merapi s southern slope a 2 500 m long co2 traverse shows low amplitude anomalies that fit well with a recently observed electromagnetic anomaly consistent with a faulted structure related to an ancient avalanche caldera rim sub surface soil permeability is the key parameter that controls the transfer of heat and volatiles within the volcano allowing its major tectonic architecture to be revealed by soil gas and soil temperature surveys

carbon dioxide and radon emissions from the soils of pantelleria island southern italy abstract in the period july 2005 october 2006 several soil gas prospections were performed on the island of pantelleria an active volcanic geothermal system at present in a quiescent state measured parameters were co2 concentrations and 220rn and 222rn activities at 50 cm depth and co2 fluxes from the soil the whole island was covered with a measurement density of 3 5 points km2 for co2 flux and concentration and 1 6 points km2 for rn further three main and seven minor areas of previously ascertained or expected exhalative activity were covered with a measurement density up to 100 points km2 the obtained results ranged from 0 038 to 95 vol for co2 concentration from 10 bq m3 to 164 000 bq m3 from 10 bq m3 to 750 000 bq m3 for 220rn and 222rn activities respectively and from

sea ice production and export from coastal polynyas in the weddell and ross seas 1 for 1992 2008 we use data from the special sensor microwave imager ssm i and the advanced microwave scanning radiometer eos amsr e to examine differences in ice production and export in the weddell and ross seas we find that the ross production is three times that in the weddell the ross export twice that in the weddell in the ross the ice production has a statistically significant positive trend of about 21 km3 y 1 and approximately equals the export while in the weddell the production trend is statistically flat and provides only about 60 of the export for each sea comparison of the ice production with the total winter sea ice volume shows that the weddell polynyas produce 5 10 of the total the ross polynyas 20 50 the explanation for these differences is that in the ross the low pressure system is better situated for generation of large polynyas than in the weddell

validation of avhrr and modis ice surface temperature products using in situ radiometers ship borne and airborne infrared radiometric measurements during the arise cruise of september october 2003 permitted in situ validation studies of two satellite based ice surface skin temperature algorithms the avhrr polar pathfinder ice surface temperature and the modis sea ice surface temperature observations of sea ice from the aurora australis ship s rail using a kt 19 82 radiometer were conducted between 25 september and 21 october during clear sky overflights by avhrr 41 passes and modis 17 passes on their respective satellite platforms data from both sensors show highly linear fits to 1 min integrated radiometer spot measurements spanning the range 245 270 k with a 1 48c 1 avhrr and 1 08c modis variation relative to a 1 1 relationship there was no significant offset helicopter observations made with a kt 19 85 radiometer on three dates 8 19 and 20 october provided more data 236 gridcell sites total but over a more limited sea ice skin tem perature range 252 268 k with higher variation 1 78c 1 due to mixed pixel issues comparison of modis and avhrr algorithms directly with both images acquired during a helicopter flight indicates very high correlation and near unity slope for the two satellite based algorithms ship air temperature data during the validation indicated moderate to strong inversions over sea ice under clear skies these formed and decayed rapidly tens of minutes as clouds moved out of and into the zenith area

measurements of 220rn and 222rn and co2 emissions in soil and fumarole gases on mt etna volcano italy implications for gas transport and shallow ground fracture this work was funded by the istituto nazionale di geofisica e vulcanologia s g m n and by the dipartimento per la protezione civile italy projects v3 6 28 etna m n and v5 08 diffuse degassing in italy s g and nsf ear 063824101 k w w s

crater lake and post eruption hydrothermal activity el chichon volcano mexico abstract explosive eruptions of volcan el chichon in chiapas mexico on march 28 and april 3 4 1982 removed 0 2 km3 of rock to form a 1 km wide 300 m deep summit crater by late april 1982 a lake had begun to form on the crater floor and by november 1982 it attained a maximum surface area of 1 4 105 m2 and a volume of 5 106 m3 accumulation of 4 5 m of rainfall between july and october 1982 largely formed the lake in january 1983 temperatures of fumaroles on the crater floor and lower crater walls ranged from 98 to 115 c by october 1983 the maximum temperature of fumarole emissions was 99 c in january 1983 fumarole gas emissions were greater than 99 vol h2o with traces of co2 so2 and h2s the water of the lake was a hot t 52 58 c acidic ph 0 5 dilute solution 34 046 mg l 1 dissolved solids cl s 20 5 sediment from the lake contains the same silicate minerals as the rocks of the 1982 pyroclastic deposits together with less than 1 of elemental sulfur the composition and temperature of the lake water is attributed to 1 solution of fumarole emissions 2 reaction of lake water with hot rocks beneath the lake level 3 sediments washed into the lake from the crater walls 4 hydrothermal fluids leaching sediments and formational waters in sedimentary rocks of the basement 5 evaporation and 6 precipitation

soil gas profiles as a tool to characterise active tectonic areas the jaut pass example pyrenees france a new method to investigate active tectonic structures using soil gas composition at faults suggests relevant information about regional stress conditions which can be obtained rapidly and at relatively low cost in 1995 we carried out geochemical profiles around the epicentre of the m 5 1 1980 earthquake near arudy in the french pyrenees where the presence of minor fractures is evident in the field and confirmed using satellite spot imagery fractures are conduits facilitating fluid migrations in the crust and are also pathways for the release of deep seated gases to the atmosphere in order to investigate the implication of these fractures in the present deformation i e if they are connected to the hercynian substratum at a depth of about 1800 m soil gases were measured along four traverses crossing the observed structures gases determined were 222rn co2 and 4he each of them for their characteristic source 222rn has essentially a shallow origin due to its short half life whereas co2 is the major soil gas component with a mainly surficial biogenic source however there could additionally be co2 from crustal or mantle degassing which would also be the principal sources of he data analysis clearly reveals anomalous values for each gas at specific positions along the traverses two sets of fractures corresponding to different observed trends are distinguished the one characterised by he anomalies accompanied by other gases and the second with few identified he anomalies the agreement between the geochemical data and the field observations leads us to propose a deformation model for the area studied analogous to a pull apart system located in a right lateral shear zone

correlations between the radon concentrations in soil gas and the activity of the anninghe and the zemuhe faults in sichuan southwestern of china abstract the anninghe fault anhf and the zemuhe fault zmhf with left lateral strike slip located along the eastern boundary of the sichuan yunnan block southwestern of china are some of the most active faults these faults mainly control the seismicity of southwestern area of china measurement of soil gas radon rn emitted from fault along the anhf and the zmhf has been carried out for the research of tectonic activity we obtained the rn concentrations at 394 sampling points along 15 profiles across the anhf and the zmhf in 2016 the measurement results show that the values of rn in the anhf are significantly higher than that in the zmhf the relative coefficient kq of rn activity attained in profiles of the anhf ranges from 3 3 to 9 1 which are obviously higher than that of 2 1 2 5 in profiles of the zmhf the radon flow brings up the deeper and radon richer gas upward through the high level cracked strata caused by the tectonic activity accounts for the anomalously high values attained the spatial variation of rn in the concentration profile and the relative coefficient kq calculated indicate that the tectonic activity of the south segment of the anhf is significantly higher than that of the north segment of the zmhf

soil co2 emissions at furnas volcano sao miguel island azores archipelago volcano monitoring perspectives geomorphologic studies and land use planning application accepted for publication in journal of geophysical research copyright 2010 american geophysical union

rn he and co2 soil gas geochemistry for the study of active and inactive faults abstract two italian areas characterized by different seismological histories were investigated to enhance the basic knowledge of gas migration mechanisms during earthquakes sharp variations occur in the movement and concentration of some gaseous species due to the evolution of the local stress regime the first area colpasquale is located in the central italian region of marche and provided a good location to study gas migration in a seismically active region the area was devastated by a sequence of shallow earthquakes over a 3 month long period september december 1997 the occurrence of this catastrophic event as well as the long duration of the seismic sequence presented a unique opportunity to study gas migration in a zone undergoing active displacement soil gas surveys were performed 1 day 1 week 1 year and 2 years after the main shock ms 5 6 in the colpasquale area in particular results highlight a change in the rn distribution during the three monitoring years indicating a variation of gas migration that may be linked to the evolution of the stress regime the second study area is located in the campidano graben southern part of sardinia island this area is characterized by seismic quiescence displaying an almost complete lack of historical earthquakes and instrumentally recorded seismicity the consistently low values observed for all analyzed gases suggest that the studied area is likely characterized by sealed non active faults that prevent significant gas migration the comparison of data from both studied areas indicate that soil gas geochemistry is useful to locate tectonic discontinuities even when they intersect non cohesive clastic rocks near the surface and thus are not visible i e blind faults

early evolution of a stratospheric volcanic eruption cloud as observed with toms and avhrr this paper is a detailed study of remote sensing data from the total ozone mapping spectrometer toms and the advanced very high resolution radiometer avhrr satellite detectors of the 1982 eruption of el chichon mexico the volcanic cloud atmosphere interactions in the first four days of this eruption were investigated by combining ultraviolet retrievals to estimate the mass of sulfur dioxide in the volcanic cloud krueger et al 1995 with thermal infrared retrievals of the size optical depth and mass of fine grained 1 10 m radius volcanic ash wen and rose 1994 our study provides the first direct evidence of gravitational separation of ash from a stratospheric gas rich plinian eruption column and documents the marked differences in residence times of volcanic ash and sulfur dioxide in volcanic clouds the eruption column reached as high as 32 km carey and sigurdsson 1986 and was injected into an atmosphere with a strong wind shear which allowed for an observation of the separation of sulfur dioxide and volcanic ash the upper more sulfur dioxide rich part of the cloud was transported to the west in the stratosphere while the fine grained ash traveled to the south in the troposphere the mass of sulfur dioxide released was estimated at 7 1 109 kg with the mass decreasing by approximately 4 1 day after the peak the mass of fine grained volcanic ash detected was estimated at 6 5 109 kg amounting to about 0 7 of the estimated mass of the ash which fell out in the mapped ash blanket close to the volcano over the following days 98 of this remaining fine ash was removed from the volcanic cloud and the effective radius of ash in the volcanic cloud decreased from about 8 m to about 4 m

thin ice thickness from satellite thermal imagery sea ice thickness is an important parameter in the surface energy exchange and mass balance of the polar oceans remote sensing offers the opportunity to monitor thin ice routinely we combine measurements of surface temperature from an advanced very high resolution radiometer avhrr with a thermodynamic ice growth model to estimate thin ice and its thickness distribution during the cold season in a beaufort sea area of perennial ice we find that thin ice up to a meter thick had a concentration of 18 in december 1990 and 3 in april 1991 thin ice concentrations near the ice edge in the greenland sea range from 20 to 50 these avhrr derived estimates generally compare well with thickness observations from upward looking sonar given the uncertainties in all the model inputs estimated from avhrr such as radiative and turbulent heat flux components and surface albedo we find that ice thickness is estimated with an uncertainty of roughly 50 the uncertainty in the cumulative thickness distribution is about 3 for ice less than 20 cm thick and about 9 for ice around 1 m thick these magnitudes are significantly smaller than the variations in thin ice observed by satellite in different months and regions we conclude that avhrr is capable of resolving the regional and seasonal variations in thin ice to a level of accuracy useful both for establishing a climatology and for testing ice models

geohydrologic geochemical and geologic controls on the occurrence of radon in ground water near conifer colorado usa abstract integrated studies of geohydrology geochemistry and geology of crystalline rocks in the vicinity of conifer colorado reveal that radon concentrations do not correlate with variations in concentrations of other dissolved species concentrations of major ions show systematic variations along selected groundwater flowpaths whereas radon concentrations are dependent on local geochemical and geologic phenomena such as localized uranium concentration in the rock or the presence of faults or folds when radon enters the flow system concentrations do not increase along flowpaths because its decay rate is fast relative to groundwater flow rates radon 222 is not in secular equilibrium with 238u and 226ra in the water therefore most of the 238u and 226ra necessary to support the waterborne 222rn must be present locally in the rock high concentrations of dissolved radon are not found in zones of high transmissivity and transmissivity is not correlated with rock type in the study area a higher transmissivity can be indicative of higher water volume to rock surface area ratios which could effectively dilute 222rn entering the water and or may indicate that emanated radon is carried away more rapidly water samples collected from individual wells over periods of several months showed significant fluctuations in the dissolved 222rn content this fluctuation may be controlled by changes in the contributions of water producing zones within the well resulting from seasonal fluctuations of the water table and or pumping stresses

major optical depth perturbations to the stratosphere from volcanic eruptions pyrheliometric period 1881 1960 a detailed chronology of major stratospheric dust veils from 1881 to 1960 has been constructed by searching the primary literature for relevant observational data of various kinds especially pyrheliometry data from 23 observing sites in both hemispheres have been reduced in a rigorous fashion to yield a table of pyrheliometric optical depth perturbations as a function of year month and latitude band to convert to visual reference wavelengths the tabular entries should be multiplied by a time dependent factor that is somewhat greater than unity ten measurable volcanic dust veils have been established in this manner and have been analyzed as to their generation transport decay and total mass these clouds arose from eruptions of krakatau 1883 an unidentified volcano 1890 soufriere and pelee 1902 santa maria 1902 ksudach 1907 katmai 1912 puyehue 1921 paluweh 1928 komagatake 1929 and quizapu 1932 other turbidity indicators have also been used in the analysis including starlight extinction purple twilight glows color of sun and moon polarization of blue sky light bishop s ring around the sun and dark lunar eclipses global stratospheric aerosol loadings have been computed from the peak turbidities agreement with the aerosol masses derived from polar ice cores is good in the important cases of krakatau santa maria and after a major correction of the ice core value katmai during the long period 1881 1992 about 80 of all stratospheric aerosols generated by the largest sulfur producing eruptions were emplaced during the two short time intervals 1883 1902 and 1982 1991 the long term 1881 1992 average annual production rate of stratospheric so2 from the largest eruptions was 0 8 tg yr 1 about half the average rate since 1981 implications of the principal results are discussed

mapping of sea ice production for antarctic coastal polynyas 1 active sea ice production in antarctic coastal polynyas causes dense water formation finally leading to antarctic bottom water aabw formation this study gives the first mapping of sea ice production in the antarctic ocean based on heat flux calculation with ice thickness data derived from satellite data the highest ice production occurs in the ross ice shelf polynya region the ice production there decreased by 30 from the 1990s to the 2000s which can be one candidate for causing the recent freshening of aabw the cape darnley polynya in east antarctica is found to be the second highest production area suggesting a possible aabw formation area according to our estimation around 10 of southern ocean sea ice is produced in the major antarctic coastal polynyas the mapping provides surface heat and salt flux conditions in the ice covered region which have not been well understood

radon variations in an active landslide zone along the pindar river in chamoli district garhwal lesser himalaya india radon measurements were made in the soil and spring seepage water in and around an active landslide located along the pindar river in the chamoli district of uttaranchal in garhwal lesser himalaya to understand the application of radon in geological disasters the landslide is a compound slide i e a slump in the crown portion and debris slide and fall in the lower part the bedrock consists of gneisses and schists of the saryu formation of the almora group of precambrian age the presence of several small slump scars and debris slide fall scars along the length of the slide indicates continuous downward movement the radon concentrations in the present study are much lower in comparison to values reported from other regions however the present radon data show relative variation in the slide zone the concentration of radon measured in landslide zones varies from 3 1 bq l to 18 4 bq l in spring water and from 2 3 kbq m3 to 12 2 kbq m3 in the soil gas of the debris along the section of the slide the radon values in water and soil are slightly higher in the upper slopes i e toward the crown portion of the landslide as compared to the distal portion the relatively low concentration of radon both in soil gas and water in the toe portion of the landslide may be due to the high porosity of the debris which does not allow radon to accumulate in the soil and water whereas towards the crown portion the high frequency of fractures increases the surface area due to particle size reduction and the near absence of debris enhances the radon emanation in soil

enhancement of atmospheric radiation by an aerosol layer the presence of a stratospheric haze layer may produce increases in both the actinic flux and the irradiance below this layer such haze layers result from the injection of aerosol forming material into the stratosphere by volcanic eruptions simple heuristic arguments show that the increase in flux below the haze layer relative to a clear sky case is a consequence of photon trapping we explore the magnitude of these flux perturbations as a function of aerosol properties and illumination conditions with a new radiative transfer model that can accurately compute fluxes in an inhomogeneous atmosphere with nonconservative scatterers having arbitrary phase function one calculated consequence of the el chichon volcanic eruption is an increase in the midday surface actinic flux at 20 n latitude summer by as much as 45 at 2900 a this increase in flux in the uv b wavelength range was caused entirely by aerosol scattering without any reduction in the overhead ozone column

improved mapping of sea ice production in the arctic ocean using amsr e thin ice thickness algorithm new and improved estimates of sea ice production in the arctic ocean are derived from amsr e satellite and atmospheric reanalysis data for the period 2002 2011 at a spatial resolution of 6 25 km and using a newly developed fast ice mask high ice production in the major coastal polynyas is well demonstrated the total annual cumulative ice production in the major 10 polynya regions is about 1180 70km 3 the interannual variability of the ice production for each polynya is presented during 2002 2011 no obvious relationship is noted between the ice production and the recent drastic reduction in the preceding summer arctic sea ice extent most polynya regions exhibit maximum ice production in autumn october november before areas offshore have been covered with consolidated pack ice sea ice production from october to november in the marginal ice zone of the pacific ocean sector is negatively correlated with summer ice extent there the ice production from october to november of 2007 a record minimum summer ice extent was about twice as large as that in other years the high ice production area shifted to higher latitudes i e toward the deep canada basin due to the retreat of the summer ice edge we speculate that the resultant increase in brine input could change the oceanic structure in the basin specifically deepening the winter mixed layer 2014 american geophysical union all rights reserved

the pyrenean earthquake of february 29 1980 an example of complex faulting abstract an m b 5 1 earthquake occurred on february 29 1980 in the western pyrenees near arudy france the telemetred network of the i p g p operating in this area since 1978 allowed a good localization of this earthquake 43 4 21 n 0 24 59 w depth 4km during the two years preceding this earthquake the seismic activity exhibited a gradual decrease a foreshock of magnitude 1 6 was recorded three hours before the main shock a temporary network set up in the epicentral area a few days after the main shock permitted a precise study of the aftershock sequence fifty fault plane solutions for earthquakes ranging from magnitude 1 5 4 were obtained a complex pattern of faulting was revealed with both strike slip and normal faulting however a regional tectonic stress tensor can be proposed from a detailed investigation of the aftershock sequence this stress tensor is in agreement with previous results in this area

seismic anisotropy around the gulf of corinth greece deduced from three component seismograms of local earthquakes and its relationship with crustal strain several thousand three component seismograms from local earthquakes recorded during two field experiments in august 1991 and november 1992 in the gulf of corinth have been analyzed to detect shear wave splitting after a first selection of the events located in the s window of the considered stations a second very strict selection of the records is applied in order to avoid the effect of scattered or converted phases which can mimic the behavior of shear wave splitting two main directions of fast s wave polarization have been detected one oriented n105 e n120 e the other n55 e n75 e the first one is perpendicular to the main direction of extension of the gulf provided by focal mechanism global positioning system measurements and tectonic studies and is thus consistent with the extensive dilatancy anisotropy eda model the second direction is subparallel to the direction of the active normal fault closest to the sites this suggests a local control of the anisotropy by these active faults either by a local rotation of the total stress field in which case the eda model may still explain the anisotropy or by the existence of a specific microstructure or macrostructure generated by the long term fault activity set of secondary fault planes parallel to the major one in which case the anisotropy direction would be significantly rotated from the stress direction about 50 the anisotropic signature does not seem to be affected by the geology of the site pre tertiary limestone and pleistocene sediments except for a station located on the thick plio quaternary deposits of a delta where the time delay is significantly larger

soil gas distribution in the main coseismic surface rupture zone of the 1980 ms 6 9 irpinia earthquake southern italy soil gas measurements of different gas species with different geochemical behaviors were performed in the area of the pecore plain a 200 m 300 m sized fault bounded extensional basin located in the northern mount marzano massif in the axial belt of the southern apennine chain the pecore plain area was affected by coseismic surface faulting during the ms 6 9 1980 irpinia earthquake the strongest and most destructive seismic event of the last 30 years in southern italy the collected data and their geostatistical analysis provide new insights into the control exerted by active fault segments on deep seated gas migration toward the surface the results define anomalies that are aligned with the nw se trending coseismic rupture of the 1980 earthquake along the western border of the plain as well as along the southern border of the plain where a hidden e w striking fault is inferred geospatial analysis highlights an anisotropic spatial behavior of 222rn along the main nw se trend and of co2 along the e w trend this feature suggests a correlation between the shape and orientation of the anomalies and the barrier conduit behavior of fault zones in the area furthermore our results show that gas migration through brittle deformation zones occurs by advective processes as suggested by the relatively high migration rate needed to obtain anomalies of short lived 222rn in the soil pores

correlated radon and co2 variations near the san andreas fault correlations have been observed between groundwater radon and thoron concentrations and carbon dioxide discharges at the lake hughes station of the caltech radon monitoring network the lake hughes site is one of three radon monitoring stations located near the big bend segment of the san andreas fault which began to record anomalous radon levels in august 1981 two stations lake hughes and lytle creek recorded anomalous increases in radon while the third sky forest recorded an anomalous decrease several weeks after the onset of the anomaly strongly correlated radon fluctuations began at lake hughes and lytle creek these radon spikes also were found to be phase anti correlated with barometric pressure fluctuations analyses of gas grab samples showed relatively high levels of co 2 and ethylene in borehole air at lake hughes and lytle creek while analyses of water samples showed relatively large increases in hco 3 at both sites isotopic analysis of one gas sample from lake hughes yielded a 13 c value of 22 which suggests that the co 2 originates from the oxidation of organic material the correlation in radon fluctuations at lake hughes and lytle creek and their common dependence on barometric pressure changes began shortly after the onset of the radon anomaly in august and probably resulted from the simultaneous saturation of the water in these boreholes with carbon dioxide

soil gas monitoring a tool for fault delineation studies along hsinhua fault tainan southern taiwan many studies have shown the soil gas method to be one of the most reliable investigation tools in the research of earthquake precursory signals and fault delineation the present research is aimed finding the relationship between soil gas distribution and tectonic systems in the vicinity of the hsinhua fault zone in the tainan area of southern taiwan more than 110 samples were collected along 13 traverses to find the spatial distribution of rn he co2 and n2 the spatial congruence of all the gases shows that n2 is the most probable carrier gas of he whereas co2 seems to be a good carrier gas of rn in this area from the spatial distribution of rn he co2 and n2 the trace of hsinhua fault and neotectonic features can be identified the spatial distribution of studied gases shows a clear anomalous trend ene sws along the hsinhua fault

soil gas radon emissions and volcanic activity at el hierro canary islands the 2011 2012 submarine eruption 1 soil gas radon 222rn and thoron 220rn activities have been continuously measured during the period of the recent volcanic unrest that occurred at el hierro canary islands at two different monitoring stations namely hie02 and hie03 significant increases in soil 222rn activity and 222rn 220rn ratio from the soil were observed at both stations prior to the 2011 2012 submarine eruption off the coast of el hierro showing the highest increases before the eruption onset and before the occurrence of the strongest seismic event m 4 6 statistical analysis showed that the long term temporal trend of filtered radon data matched closely that of seismic energy release during the volcanic unrest the observed increases of 222rn are related to the rock fracturing processes seismic activity and the magmatic co2 outflow increase as observed in hie03 station

latitudinal survey of spectral optical depths of the pinatubo volcanic cloud derived particle sizes columnar mass loadings and effects on planetary albedo we have made airborne measurements of spectral optical depths radiative fluxes and scattered radiation fields during the nasa caribbean mission july 7 14 1991 to characterize the pinatubo volcanic cloud in this paper we report the latitudinal and spectral dependence of the volcanic cloud s optical depth from these measurements we determine moments of the particle size distribution the change in planetary albedo induced by the volcanic cloud is calculated for the range of measured optical depths with the objective of assessing the impact on the solar radiation budget mid visible optical depths higher than 0 4 were observed placing the pinatubo stratospheric cloud among the thickest ever measured the latitudinal distribution of extinction shows that by july 7 1991 the volcanic cloud had extended to 30 n the effective particle radius was determined to be between 0 18 m and 035 m with a corresponding columnar mass loading between 35 and 80 mg m 2

the effects of environmental parameters on diffuse degassing at stromboli volcano insights from joint monitoring of soil co2 flux and radon activity abstract soil co 2 flux and 222 rn activity measurements may positively contribute to the geochemical monitoring of active volcanoes the influence of several environmental parameters on the gas signals has been substantially demonstrated therefore the implementation of tools capable of removing or minimising the contribution of the atmospheric effects from the acquired time series is a challenge in volcano surveillance here we present 4 years long continuous monitoring from april 2007 to september 2011 of radon activity and soil co 2 flux collected on the ne flank of stromboli volcano both gases record higher emissions during fall winter up to 2700 bq m 3 for radon and 750 g m 2 day 1 for co 2 than during spring summer seasons short time variations on 222 rn activity are modulated by changes in soil humidity rainfall and changes in soil co 2 flux that may be ascribed to variations in wind speed and direction the spectral analyses reveal diurnal and semi diurnal cycles on both gases outlining that atmospheric variations are capable to modify the gas release rate from the soil the long term soil co 2 flux shows a slow decreasing trend not visible in 222 rn activity suggesting a possible difference in the source depth of the of the gases co 2 being deeper and likely related to degassing at depth of the magma batch involved in the february april 2007 effusive eruption to minimise the effect of the environmental parameters on the 222 rn concentrations and soil co 2 fluxes two different statistical treatments were applied the multiple linear regression mlr and the principal component regression pcr these approaches allow to quantify the weight of each environmental factor on the two gas species and show a strong influence of some parameters on the gas transfer processes through soils the residual values of radon and co 2 flux i e the values obtained after correction for the environmental influence were then compared with the eruptive episodes that occurred at stromboli during the analysed time span 2007 2011 but no clear correlations emerge between soil gas release and volcanic activity this is probably due to i the distal location of the monitoring stations with respect to the active craters and to ii the fact that during the investigated period no major eruptive phenomena paroxysmal explosion flank eruption occurred comparison of mlr and pcr methods in time series analysis indicates that mlr can be more easily applied to real time data processing in monitoring of open conduit active volcanoes like stromboli where the transition to an eruptive phase may occur in relatively short times

soil gas emanations as precursory indicators of volcanic eruptions field measurements conducted on several active volcanoes in italy the lesser antilles and indonesia demonstrate the common occurrence of diffuse soil gas emanations from the volcanic piles at distances from active craters or fumarolic zones these emanations consist essentially of carbon dioxide and rare gases and their genetic link with crater fumaroles and or magma degassing at depth can be verified both chemically and isotopically we emphasize here the potential use of these fluids for continuous volcano monitoring and eruption forecasting

geochemical characterization of the nirano mud volcano italy abstract the nirano mud volcano is located in the western sector of the modena apennine margin italy it represents one of the most spectacular phenomena of sedimentary volcanism in the entire italian territory and is among the largest in europe here numerous aligned gryphon clusters and seeping pools constantly burst gas and mud inside a morphological depression besides the obvious surface expressions of these emission spots until now the type and amount of gas released in the rest of the large nirano caldera zone remained unknown an extensive geochemical soil gas survey o2 n2 co2 ch4 222rn he h2 and light hydrocarbons and exhalation fluxes co2 and ch4 was carried out inside the mud volcano field with the aim of identifying soil degassing distribution and to estimate the micro and macro seepage budget for both co2 and ch4 soil gas data highlight the presence of two zones characterized by high concentrations and flux values these enhanced seepage zones are located in the sw and ne sectors of the mud volcano suggesting that the enhanced gas emissions present in the peripheral zones are controlled by caldera collapse structures the most significant co2 flux up to 91 g m 2 d 1 and 222rn anomalies are located in the central part of the crater in correspondence of a morphological escarpment here we infer the presence of a buried tectonic system of collapsed terraces that facilitate fluids degassing in contrast ch4 fluxes show a scattered distribution and low values mean 221 mg m 2 d 1 overall the ch4 degassing budget is low 27 09 t km 2 y 1 when compared with other italian mud volcanoes this could be related to a relative low emission activity during the period of the geochemical survey and to a more homogeneous dilution of surface distribution of the emission point s chemical and isotopical composition of the gas discharged from the active gryphons is methane dominated and the thermogenic signature ranging from 41 to 47 suggests a deep reservoir source this conclusion is supported by noble gas measurements he ne ar kr xe conducted in the pore water phase of the emitted mud indicating a secondary gas exchange occurring at a depth of a few kilometers the geochemical anomalies found in this study successfully predicted the occurrence of new degassing phenomena towards the ne sector of the caldera indeed recently i e after the survey data acquisition new manifestations of mud and gas emissions appeared in the north eastern edge of the caldera

the effect of volcanic aerosols on global climate abstract the surface temperature decrease after major volcanic eruptions has been demonstrated by a number of groups to be the order of a few tenths of a degree at first the stratospheric aerosol is usually restricted to a narrow range of latitudes and the volcanically induced temperature decrease is found to be nonuniform over the surface of the earth in fact because of the differential cooling of land and ocean there should always be volcanically induced temperature gradients these temperature gradients will induce a redistribution of air mass and anomalous sea level pressure gradients anomalous winds and anomalous climate on a global scale in this paper a hypothesis is presented which assumes that volcanic aerosols by reducing the solar radiation induces surface temperature gradients and sea level pressure gradients between the land and the oceans since cooling of the land occurs before the oceans there will be at first an increase of sea level pressure over land relative to the oceans conservation of total air mass on a global scale requires the sea level pressure over the ocean to be reduced because the majority of the land area is in the northern hemisphere the volcanically induced cooling will transfer air mass from the oceanic anticyclones in both the northern and southern hemisphere to the continents and especially to southern eurasia the anomalous sea level pressure pattern slp which would be obtained higher slp over southern eurasia and lower slp over the southern oceans is very close to the pattern first named by sir gilbert walker called the negative phase of the southern oscillation the positive phase of the southern oscillation can occur when no volcanic aerosols are present and the stratosphere is clear then the additional radiation and heating of the land increases the transfer of air mass from the northern hemisphere land mass to the world s oceans the positive phase of the global southern oscillation in this paper it will be shown that this hypothesis has the potential to explain the observed association between low latitude volcanic aerosols and the el nino southern oscillation it also has the potential to explain why el chichon s eruption induced a very strong el nino compared to the weaker el nino events induced by the eruptions of agung and krakatau it also explains why almost all monsoon countries experience below normal precipitation just prior to the maximum of the el nino warming the hypothesis also has the potential to explain why low and high latitude aerosols will affect the global climate system differently this hypothesis represents a return to the ideas of sir gilbert walker who first defined the southern oscillation as a global scale anomaly rather than an index between just two stations

geological and tectonic influence on water soil radon relationship in mandi manali area himachal himalaya radon measurements in soil and groundwater springs thermal springs and handpumps were made in a variety of lithological units including major thrusts between mandi and manali in himachal himalaya analysis of radon data in light of lithological controls and influence of deep seated thrusts has been made to elucidate the causative factors for anomalous emanation of radon the lithological types include banded gneisses schists quartzite granite phyllites volcanics and mylonites the low grade metasedimentries of shali and dharamsala generally show low and narrow range of radon concentration in water 5 6 13 4 bq l as well as in soil 1 8 3 2 kbq m3 except for the samples related to thrusts on the other hand sheared and deformed rocks of chail and jutogh show moderate radon content average 5 03 kbq m3 range 2 9 11 1 kbq m3 in soil however the groundwater radon concentration shows wide variation in different types of sources 2 1 80 8 bq l the quartzite and volcanic rocks of rampur formation in this area present as a window separated by chail thrust radon emanations on these rock types are relatively high 6 3 68 1 bq l in water and 5 5 15 9 kbq m3 in soil and are exceptionally high in samples that are related to uranium mineralization deep seated thrusts and hot springs 13 5 653 5 bq l it is generally observed that anomalous high radon content is associated with mineralization deeper source and tectonic discontinuities whereas it is obvious that subsurface radioactive mineralization would facilitate enhanced radon production however thrust plains provide easy pathways for escape of gases from the deeper sources shallow and deep sources of the groundwater have contrasting radon content particularly in the deformed and metamorphosed rocks of jutogh and chail shallow groundwater sources mainly handpumps have lower radon concentration due to limited superficial water circulation whereas deeper sources mainly perennial springs show higher radon content because of larger opportunity for water rock interaction

radon anomalies on three kinds of faults in california radon emanation is known to be anomalously high along active faults in many parts of the world we tested this relationship in california during july and early august 1992 using a portable radonmeter to conduct soil air radon surveys at 5 sites across three kinds of faults creeping locked and freshly broken along a 350 m long survey line across a creeping segment of the san andreas fault at nyland ranch in san juan bautista we found anomalous radon concentrations not in the creep zone itself as determined by a creepmeter but on the adjacent sides 10 and 30 meters from the center line of the fault the anomalous values were 5 times higher than the background values measured farther away from the fault a similar radon anomaly was observed along a 420 m long survey line across a creeping segment of the calaveras fault near 7th street in hollister there the anomalous values were about 6 to 11 times the background values and about 40 and 50 m from the center line of the fault the double peaked featire of the anomalies may be indicative of a relatively low gas permeability of the fault gouge materials in the creeping zones and high permeability of fractured rocks in the adjacent shear zones along a 144 m survey line across the currently locked segment of the san andreas fault at the earthquake trail near olema the radon concentration was indeed anomalously high in the fault zone by a factor of two above background values however the maximum values 3 to 6 times background again were recorded about 10 meters from the center line three weeks after the magnitude 7 5 landers earthquake of 28 june 1992 we conducted a survey along a 300 m line across the earthquake fault alongside encantado road in the epicenter area the radon values measured at the two main fault breaks were an order of magnitude higher than the background values a similar result was found along a 420 m line alongside reche road about 1 7 km south of encantado road

on some radiative features of the el chichon volcanic stratospheric dust cloud and a cloud of unknown origin observed at mauna loa we present some results of our initial optical observations of the el chichon volcanic cloud these observations were made at the geophysical monitoring for climatic change mauna loa observatory hawaii and consist of lidar profiles optical thickness spectral variation in optical thickness and changes in global and direct solar broadband fluxes particle size distribution and cloud mass information contained in the optical thickness observations are discussed it is clear that the atmospheric radiative effects of the el chichon cloud far exceed the effects of all other volcanic clouds observed at mauna loa since observations were begun in 1958

observations of ice thickness and frazil ice in the st lawrence island polynya from satellite imagery upward looking sonar and salinity temperature moorings 1 for the 1999 winter this paper examines the behavior of the bering sea st lawrence island polynya using a combination of advanced very high resolution radiometer avhrr radarsat synthetic aperture radar sar meteorological data over winter moored upward looking sonars uls and seabird salinity temperature sensors we define a thermal ice thickness from the avhrr retrieval of ice surface temperature combined with meteorological observations and a heat flux model south of the island we compare the uls and thermal thicknesses for congelation and frazil ice when the satellites observe congelation ice over the ulss the uls and thermal ice thicknesses generally agree when sar observes langmuir plumes over the ulss which indicate frazil ice formation the ulss show scatterers at 5 20 m depths in the water column and the seawater temperatures are either within 0 01 c of freezing or are slightly supercooled this suggests that during frazil events crystals either nucleate at depth or are transported to depth by the langmuir circulation the combination of the sar imagery and uls observations also allow measurement of the pack ice advection velocity the polynya width and the downwind frazil accumulation thickness giving widths of 10 to 30 km and thicknesses of 0 1 0 2 m substitution of these observed values with the heat flux into the pease polynya model yields polynya widths that approximately agree with the observed