structure of chlorella fusca algaenan relationships with ultralaminae in lacustrine kerogens species and environment dependent variations in the composition of fossil ultralaminae numerous kerogens from marine and lacustrine source rocks and oils shales previously considered as amorphous were recently shown to comprise very thin 10 30 nm thick lamellar structures termed ultralaminae comparative morphological and chemical studies of a lacustrine ultralaminae rich kerogen and of the non hydrolysable biopolymer algaenan isolated from the thin resistant outer walls of a freshwater microalga scenedesmus quadricauda established a close relationship between these two materials chemical correlation was mainly based on the production upon pyrolysis of a series of n alkylnitriles with a bimodal distribution the non hydrolysable biopolymer isolated from the outer walls of the ubiquitous freshwater microalga chlorella fusca exhibits the same morphologicalfeatures as those observed in s quadricauda and in fossil ultralaminae the investigation of c fusca algaenan by solid state 13c nmr and analysis of pyrolysis products revealed that the correlation previously established between s quadricauda and lacustrine ultralaminae also holds for c fusca since the same series of n alkylnitriles with the same distribution is formed upon pyrolysis probably via cleavage of amide functions this confirms that fossil ultralaminae in lacustrine kerogens derive from the algaenans building up the thin outer walls of freshwater microalgae via the selective preservation pathway in addition the analysis of the 2 n alkanones generated on pyrolysis indicates that their distribution depends on the algal species considered accordingly variations in ketone distributions in the pyrolysates of lacustrine ultralaminae rich kerogens may reflect differences in populations of the source microalgae on the contrary changes in n alkylnitrile distribution would not be species dependent but would reflect the lacustrine or marine origin of the considered material

effect of ocean oxidation on the chemical structure of marine kerogen abstract the burial of organic matter om in marine sediments is an important control on global climate and petroleum formation on geological timescales while the oxygen exposure time of sediment has been shown to affect the efficiency of organic carbon burial and influence om properties in recent sediments the implications for the chemical composition of kerogen have not been tested this study tests the hypothesis that oceanic redox conditions are an important control on the molecular structure and composition of kerogen samples from a number of outcropping late cretaceous mudstones of the eagle ford formation were chosen spanning a gradient of paleo redox depositional conditions oxic sub oxic to anoxic and the bulk molecular composition of the kerogen was determined using solid state 13 c nuclear magnetic resonance nmr spectroscopy the nmr spectral properties of kerogen covaried with redox sensitive trace metal abundance whereas the thermal maturity and om source biomarkers were relatively invariant anoxic environments favor the preservation of alkyl c moieties while kerogen formed in oxic depositional environments was enriched in aromatic c this study is the first to demonstrate that diagenetic consequences of bottom water redox conditions are retained in the molecular structure of the kerogen macromolecule on geological timescales

regional scale co seismic landslide assessment using limit equilibrium analysis abstract traditionally regional assessment of seismic slope stability has been done using the infinite slope rigid sliding block analysis a major disadvantage of this approach is the resulting overestimation of the critical acceleration of the slope due to the underlying assumption of a predefined slope failure plane and consequently the underestimation of hazard areas prone to sliding in this paper we present a modified approach for assessing seismic slope instabilities using a model based on limit equilibrium analysis and circular slip surfaces with no restriction to any predefined slope failure plane for this purpose we conduct a parametric study to identify the relationship between the critical acceleration of the slope the slope angle and the slope shear strength parameters we model typical slopes in the rocscience software slide using bishop s limit equilibrium method to identify the critical accelerations that corresponds to a failure plane with factor of safety equal to one the critical accelerations were plotted against the variables in the parametric study and the best fit equations were obtained the proposed approach was developed for global application but it was tested using the well documented co seismic landslide database of the 1994 northridge ca earthquake the predicted sliding areas were compared to the inventory of landslides that were triggered in the val verde region in los angeles by the earthquake qualitative and quantitative assessments of the proposed model clearly show its advantages in predicting potential sliding areas

case history of landslide movement during the northridge earthquake we document a case history of northridge earthquake induced movement of a coherent landslide mass comprised principally of weathered previously sheared siltstone information on the residual shear strength of the material through which the sliding occurred is available both from backanalysis of a static rainfall induced failure on the same slope and laboratory test data postearthquake field reconnaissance data establishes the seismic slope displacements near the slope crest a yield coefficient is estimated for the slope based on residual shear strengths and measured groundwater levels at the time of the northridge earthquake this yield coefficient is used with four horizontal equivalent acceleration time histories that approximate the seismic demand within the slide mass in newmark sliding block displacement analyses the calculated displacements range from approximately 20 to 90 mm which compares well with observed displacements at the slide scarp of approximately 50 mm

occurrence of phenylalkanes in some australian crude oils and sediments evidence is presented to support the proposition that phenylalkanes in some australian crude oils and sediments are of geochemical origin as opposed to resulting from contamination from byproducts of the petrochemical manufacture of surfactants evidence presented shows that 1 an unexposed sediment core was found to contain phenylalkanes 2 the molecular weight range of phenylalkanes in sediments and crude oils is usually wider than that found in surfactants extending in some cases beyond c35 3 abundant phenylalkanes were generated by pyrolysis of extracted sediments and 4 phenylalkanes were found in the neutral lipid extract of extant thermoplasma bacteria also the presence of phenylalkanes and possibly phenylalkenes in the pyrolyzates of torbanites suggests that these compounds may also be formed from fossil algae

impact of atmospheric water vapor on the thermal infrared remote sensing of volcanic sulfur dioxide emissions a case study from the pu u o vent of kilauea volcano hawaii the december 18 1999 launch of nasa s terra satellite put two multispectral thermal infrared imaging instruments into earth orbit experiments with airborne instruments have demonstrated that the data from such instruments can be used to detect volcanic so2 plumes and clouds however one of the greatest challenges that will confront efforts to monitor volcanic so2 emissions from space is the need to characterize the local atmosphere in this paper we evaluate the sensitivity of the so2 retrieval procedure to our knowledge of the local atmospheric conditions we compare so2 retrievals obtained with distant radiosonde and local fourier transform infrared ftir soundings atmospheric measurements and find that the relative difference is typically 25 for ground temperature retrievals the relative difference is 1 5 these results lead us to conclude that while local measurements of atmospheric conditions are preferable useful retrievals can be obtained using atmospheric measurements from distant sites in addition we find very good agreement between so2 and ground temperature retrievals obtained from thermal infrared imagery and ftir soundings

plume tracker interactive mapping of volcanic sulfur dioxide emissions with high performance radiative transfer modeling abstract we describe the development of plume tracker an interactive toolkit for the analysis of multispectral thermal infrared observations of volcanic plumes and clouds plume tracker is the successor to map so2 and together these flexible and comprehensive tools have enabled investigators to map sulfur dioxide so 2 emissions from a number of volcanoes with tir data from a variety of airborne and satellite instruments our objective for the development of plume tracker was to improve the computational performance of the retrieval procedures while retaining the accuracy of the retrievals we have achieved a 300 improvement in the benchmark performance of the retrieval procedures through the introduction of innovative data binning and signal reconstruction strategies and improved the accuracy of the retrievals with a new method for evaluating the misfit between model and observed radiance spectra we evaluated the accuracy of plume tracker retrievals with case studies based on modis and airs data acquired over sarychev peak volcano and aster data acquired over kilauea and turrialba volcanoes in the sarychev peak study the airs based estimate of total so 2 mass was 40 lower than the modis based estimate this result was consistent with a 45 reduction in the airs based estimate of plume area relative to the corresponding modis based estimate in addition we found that our airs based estimate agreed with an independent estimate based on a competing retrieval technique within a margin of 20 in the kilauea study the aster based concentration estimates from 21 may 2012 were within 50 of concurrent ground level concentration measurements in the turrialba study the aster based concentration estimates on 21 january 2012 were in exact agreement with so 2 concentrations measured at plume altitude on 1 february 2012

a scenario study of seismically induced landsliding in seattle using broadband synthetic seismograms abstract we demonstrate the value of utilizing broadband synthetic seismograms to assess regional seismically induced landslide hazard focusing on a case study of an m w 7 0 seattle fault earthquake in seattle washington we computed broadband synthetic seismograms that account for rupture directivity and 3d basin amplification we then adjusted the computed motions on a fine grid for 1d amplifications based on the site response of typical geologic profiles in seattle and used these time series ground motions to trigger shallow landsliding using the newmark method the inclusion of these effects was critical in determining the extent of landsliding triggered we found that for inertially triggered slope failures modeled by the newmark method the ground motions used to simulate landsliding must have broadband frequency content in order to capture the full slope displacement we applied commonly used simpler methods based on ground motion prediction equations for the same scenario and found that they predicted far fewer landslides if only the mean values were used but far more at the maximum range of the uncertainties highlighting the danger of using just the mean values for such methods our results indicate that landsliding triggered by a large seattle fault earthquake will be extensive and potentially devastating causing direct losses and impeding recovery the high impact of landsliding predicted by this simulation shows that this secondary effect of earthquakes should be studied with as much vigor as other earthquake effects online material high resolution maps of relative seismically induced landslide hazard for an m w 7 0 seattle fault earthquake for dry and saturated soil conditions

comparative studies of the kinetic parameters of various algaenans and kerogens via open system pyrolyses abstract kinetic parameters were determined for the first time via open system pyrolyses on algaenans highly resistant biomacromolecules that are selectively preserved during kerogen formation isolated from extant microalgae parallel studies were also carried out on 10 kerogens exhibiting with one exception a low level of maturity these kerogens included samples chiefly derived from the selective preservation of the above algaenans and samples mainly or almost exclusively derived from the natural vulcanization pathway important differences in activation energy e a distributions were observed between the four algaenans investigated and correlated with their chemical structures the kerogens predominantly derived from algaenan selective preservation pula alginite ne 70 and bj 248 torbanites rundle oil shale also exhibited pronounced differences in e a distributions these distributions provided i information on the diversity of the source materials and ii reflected the occurrence of important differences in chemical structures and thermal behaviour between three of the tested kerogens even though they are all classified as low maturity type i the kimmeridge clay samples and the lorca oil shale showed broad e a distributions shifted to low energies when compared with the above algaenans and kerogens such shifts reflect an important or even almost exclusive for some of these kerogens contribution of materials originating from sulphur incorporation into various lipids during early diagenesis finally the kinetic data derived for the nine low maturity fossil samples were extrapolated to a very low geological heating rate of 3 c ma 1 and the generation rate curves and cumulative yield curves thus obtained were compared

13c and 15n nmr spectroscopic investigation on the formation of fossil algal residues 13c and 15n nmr spectroscopy was applied to modern a mixed algal culture its algaenan and its compost ancient algal derived sediments from mangrove lake bermuda and fossilized algal residues torbanite green river shale for the purpose of establishing the forms of nitrogen algal remains and evaluating their long term stabilities the results indicate that proteinaceous material can resist microbial degradation in sediments as old as 4000 yr possibly in refractory biopolymers by encapsulation into their macromolecular network the 15n nmr spectra of the torbanite and the green river shale show a relative enrichment of heterocyclic n which may derive from selective preservation of biogenic heterocyclic compounds or by rearrangement of peptide chains during diagenesis

a field study of the chemical weathering of ancient sedimentary organic matter weathering profiles developed on organic carbon rich black shales were studied to examine the loss and degradation of organic matter om during weathering and its role in the geochemical carbon cycle analysis of weathered shales reveals between 60 and nearly 100 total organic carbon toc loss in highly weathered samples relative to initial unweathered toc content pyrite loss coincides with or precedes organic carbon loss elemental analysis and flash pyrolysis gas chromatography py gc of kerogen concentrates indicate that there is little or no selective enrichment or depletion of norg containing sorg containing alkylaromatic branched alkyl or long chain n alkyl moieties in most profiles during weathering kerogen o c ratios consistently increase with toc and pyrite loss infrared spectroscopy ir reveals an increase in the relative abundance of c c and c o bonds relative to alkyl c h bonds in progressively weathered samples these results suggest a two component model for kerogen weathering largely non selective oxidation and hydration followed by cleavage dissolution of oxidized kerogen fragments the extent of weathering in a given outcrop is likely limited by a combination of the rate of physical erosion and exposure of the rock to oxidizing surface waters with om type composition playing a lesser role

simplified procedure for estimating seismic slope displacements for subduction zone earthquakes abstractseismic slope displacements are estimated for earth structures or natural slopes subjected to interface earthquakes in subduction zones the fully coupled nonlinear seismic slope displacem

observation of so2 degassing at stromboli volcano using a hyperspectral thermal infrared imager abstract thermal infrared tir imaging is a common tool for the monitoring of volcanic activity broadband cameras with increasing sampling frequency give great insight into the physical processes taking place during effusive and explosive event while fourier transform infrared ftir methods provide high resolution spectral information used to assess the composition of volcanic gases but are often limited to a single point of interest continuing developments in detector technology have given rise to a new class of hyperspectral imagers combining the advantages of both approaches in this work we present the results of our observations of volcanic activity at stromboli volcano with a ground based imager the telops hyper cam lw when used to detect emissions of sulfur dioxide so2 produced at the vent with data acquired at stromboli volcano italy in early october of 2015 we have developed an innovative technique based on a curve fitting algorithm to quickly extract spectral information from high resolution datasets allowing fast and reliable identification of so2 we show in particular that weak so2 emissions such as inter eruptive gas puffing can be easily detected using this technology even with poor weather conditions during acquisition e g high relative humidity presence of fog and or ash then artificially reducing the spectral resolution of the instrument we recreated a variety of commonly used multispectral configurations to examine the efficiency of four qualitative so2 indicators based on simple brightness temperature difference btd our results show that quickly changing conditions at the vent including but not limited to the presence of summit fog render the establishment of meaningful thresholds for btd indicators difficult building on those results we propose recommendations on the use of multispectral imaging for so2 monitoring and routine measurements from ground based instruments

a comparison of so 2 retrieval techniques using mini uv spectrometers and aster imagery at lascar volcano chile the advanced spaceborne thermal emission and reflection radiometer aster is a useful tool for detecting low quantities of sulfur dioxide at passively degassing volcanoes such as lascar volcano chile two mini uv spectrometers muses were used to make transects of lascar volcano s sulfur dioxide plume on december 7 2004 during a coordinated overpass of aster so2 burdens were retrieved using the thermal infrared channels of the acquired aster image this allowed for a direct comparison between the two methods in order to validate the aster so2 retrieval the results were extremely encouraging with aster deriving so2 fluxes within the range of fluxes obtained by the muse

kerogen chemical structure and source organisms in a cenomanian organic rich black shale central italy indications for an important role of the sorptive protection pathway abstract the bonarelli horizon is an important cenomanian turonian black shale in the umbria marche appenines of central italy it appears as the final term of a cyclic deposition of ca 40 thinner laminated clayey or siliceous organic rich levels the kerogen of the cenomanian clayey black level located 12 m below the bonarelli termed nn 8c was examined via microscopic spectroscopic and pyrolytic methods the chemical structure of this kerogen is based on a network of long aliphatic chains linked via ether bridges however in addition to the classical normal chains nn 8c comprises c40 chains with a lycopane skeleton such chains have only been previously reported in kerogen pyrolysates of two samples derived from the microalga botryococcus braunii however any contribution of b braunii can be ruled out in the case of nn 8c kerogen since it is nanoscopically amorphous based on 13c values of their pyrolysis products a common algal origin is demonstrated for the above two types of chains and hence there is a major algal input to this kerogen however some incorporation of bacterial lipids and a low contribution of higher plant material are indicated by the nature of some pyrolysis products although a large contribution of pyrite is noted in the nn 8c sample thus revealing an intense sulphate reducing activity no significant sulphur incorporation took place in the organic matter accordingly the vulcanization pathway is not implicated in the formation of nn 8c kerogen the selective preservation and the degradation recondensation pathways were possibly involved but they are unlikely to have played a major role in fact the sorptive protection process favoured by the clayey nature of the mineral matrix was probably the main pathway implicated in the formation of nn 8c kerogen and this process may have provided an efficient protection to various diagenetically sensitive constituents especially lipids

occurrence and origin of ultralaminar structures in amorphous kerogens of various source rocks and oil shales abstract forty low maturity type i ii kerogens from source rocks and oil shales ranging in age from infra cambrian to miocene were examined by transmission electron microscopy tem when previously observed by light microscopy and or uv fluorescence microscopy the above samples like a very large number of kerogens seemed homogeneous and amorphous in fact tem revealed the presence of ultralaminar structures in 22 of these amorphous kerogens the abundance of ultralaminae depends on the considered sample and some of the tested kerogens are nearly exclusively composed of ultralamina accumulations based on thickness three main groups of ultralaminae can be identified parallel studies on extant algae indicated that some of the above ultralaminae likely derived from the resistant outer walls of microalgae the fossilization of such outer walls should occur via the selective preservation pathway and result in the formation of highly aliphatic ultralaminar kerogens the lack of ultralaminae in infra cambrian kerogens is consistent with a cyanobacterial origin

motions of gently sloping ground during earthquakes 1 during past earthquakes gently sloping ground surfaces have been observed to shift laterally over areas as large as a few square kilometers these permanent downward motions have been attributed to temporary and partial reductions in shear strength of soil deposits e g liquefaction static gravity forces and transient earthquake shakings these motions the amplitudes of which remain challenging to predict have been frequently modeled using newmark sliding blocks for ground that is statically stable and occasionally partially or completely loses its shear strength during earthquakes this paper investigates in more details the deformations of gently sloping ground that becomes temporarily unstable under the combined effects of gravitational forces and earthquake shakings using a physical model we propose two definitions of earthquake contributions to the displacement of gently sloping ground which may include or not the effects of initial velocity in both cases monte carlo simulations reveal that motions of gently sloping ground are influenced by pulses of earthquake ground velocity for a wide range of reduction in soil shear strength even for very severe loss of shear strength for practical purposes when large soil deposits become unstable during earthquakes the analysis concludes that the motions of gently sloping ground are likely influenced by earthquake ground velocity

evaluation of simplified methods for predicting earthquake induced slope displacements in earth dams and embankments abstract this paper provides a review and comparison of existing simplified displacement based sliding block models analyses were performed to evaluate the relative accuracy of fifteen of these simplified models for predicting earthquake induced displacements to accomplish this task the predictive capability of the models was assessed by comparing model predictions with the actual displacements that were observed after earthquake shaking in 122 case histories of earth dams and embankments the results indicate that the model predictions of displacement were less than the observed displacement for a large majority of the case histories that were examined the difference between the observed and predicted displacements was relatively large for a significant percentage of the cases for each model that was examined the shapes and positions of the models relative error cumulative distribution functions did not change significantly if the case histories were filtered to include only those with intermediate levels of observed displacement i e 0 01 m

using picosatellites for 4 d imaging of volcanic clouds proof of concept using iss photography of the 2009 sarychev peak eruption abstract volcanic ash clouds can present an aviation hazard over distances of thousands of kilometres and to help to mitigate this hazard advanced numerical models are used to forecast ash dispersion in the atmosphere however forecast accuracy is usually limited by uncertainties in initial conditions such as the eruption rate and the vertical distribution of ash injected above the volcano here we demonstrate the potential of the telematics earth observation mission tom picosatellite formation due for launch in 2020 to provide valuable information for constraining ash cloud dispersion models through simultaneous image acquisition from three satellites tom will carry commercial frame cameras using photogrammetric simulations we show that such data should enable ash cloud heights to be determined with a precision 30 140 m depending on configuration comparable to the vertical resolution of lidar observations 30 180 m depending on the cloud height to support these estimates we processed photographs taken from the international space station of the 2009 sarychev peak eruption as a proxy for tom imagery structure from motion photogrammetric software successfully reconstructed the 3 d form of the ascending ash cloud as well as surrounding cloud layers direct estimates of the precision of the ash cloud height measurements as well as comparisons between independently processed image sets indicate that a vertical measurement precision of 200 m was achieved image sets acquired at different times captured the plume dynamics and enabled a mean ascent velocity of 14 m s 1 to be estimated for regions above 7 km in contrast the uppermost regions of the column at a measured cloud top height of 11 km were not ascending significantly enabling us to constrain a 1 d plume ascent model from which estimates for the vent size 50 m and eruption mass flux 2 6 106 kg s 1 could be made thus we demonstrate that nanosatellite imagery has the potential for substantially reducing uncertainties in ash dispersion models by providing valuable information on eruptive conditions

multispectral thermal infrared mapping of sulfur dioxide plumes a case study from the east rift zone of kilauea volcano hawaii the synoptic perspective and rapid mode of data acquisition provided by remote sensing are well suited for the study of volcanic so2 plumes in this paper we describe a plume mapping procedure that is based on image data acquired with nasa s airborne thermal infrared multispectral scanner tims and apply the procedure to tims data collected over the east rift zone of kilauea volcano hawaii on september 30 1988 these image data covered the pu u o o and kupaianaha vents and a skylight in the lava tube that was draining the kupaianaha lava pond our estimate of the so2 emission rate from pu u o o 17 20 kg s 1 is roughly twice the average of estimates derived from correlation spectrometer cospec measurements collected 10 days prior to the tims overflight 10 kg s 1 the agreement between the tims and cospec results improves when we compare so2 burden estimates which are relatively independent of wind speed we demonstrate the feasibility of mapping pu u o o scale so2 plumes from space in anticipation of the 1998 launch of the advanced spaceborne thermal emission and reflectance radiometer aster

relationships between environmental conditions and the diagenetic evolution of organic matter derived from higher plants in a modern mangrove swamp system guadeloupe french west indies abstract the sedimentary organic matter content of a series of 2 m deep cores was investigated along a sea land transect at five sites representing five species of mangrove and salt marsh vegetation the vegetation was settled at the same place for at least 1000 years and therefore sedimentary organic matter deriving from the decay of higher plants has accumulated in large amounts the global morphological and chemical preservation of the organic matter attested by various sedimentary parameters including the proportions of cellulose bearing tissues the toc contents the c n ratios the total sulphur contents and the 13 c compositions reveals that the sedimentary organic matter is less degraded when it has been under the influence of the marine water table for a long time this is indicated by a good correlation between the salinities of interstitial waters the redox potentials measured in the wet sediments and the chemical composition of the organic matter moreover the concentration of organic sulphur shows a positive correlation with the hydrogen index hi only under the marine water table influence suggesting the very local presence of sulphur hc compounds

organic geochemical characterization of a miocene core sample from haughton impact structure devon island nunavut canadian high arctic extremely well preserved sedimentary deposits in the haughton impact structure his provide a unique record of the post impact miocene lacustrine depositional environment detailed organic geochemical characterization of a hydrocarbon impregnated band found in a core from the crater lake sedimentary infill reveals a complex source history for the hydrocarbons these include contributions from eroded pre and post impact formations together with inputs from contemporaneous flora and fauna a deep possibly lower paleozoic petroleum as well as a contribution from hydrothermally altered organic biopolymers geochemical data coupled with paleolimnology and geology proves to be a valuable tool for studying the provenance of hydrocarbons associated with the his and can give insights not only into the post impact geology but also into processes that may contribute to the generation of petroleum fluids at other impact sites

so2 emissions at mt etna with particular reference to the period 1993 1995 the variations in sulfur dioxide so2 emission from the summit craters of mt etna were determined with particular reference to the period 1993 1995 vehicle based weekly measurements of so2 flux using a correlation spectrometer cospec suggest new input of magma into the main feeder system of the volcano between 1993 and 1995 minimal flux values 1000 t day preceded the two eruptive events in the period 1987 1995 only approximately 9 5 of the magma that contributed the so2 emission was erupted during the same period

volcanic plume elevation model and its velocity derived from landsat 8 abstract in this paper we present a method to restitute the volcanic gas ash plume elevation model pem from optical satellite imagery as the volcanic plume is moving rapidly conventional satellite based photogrammetric height restitution methods do not apply as the epipolar offset due to plume motion adds up to the one generated by the stereoscopic view this is because there are time lags of tens of seconds between conventional satellite stereoscopic acquisitions depending on the stereo acquisition mode our method is based on a single satellite pass we exploit the short time lag and resulting baseline that exist between the multispectral ms and the panchromatic pan bands to jointly measure the epipolar offsets and the perpendicular to the epipolar p2e offsets the first are proportional to plume height plus the offsets due to plume velocity in the epipolar direction the second are proportional to plume velocity in the p2e direction only the latter is used to compensate the effect of plume velocity in the stereoscopic offsets by projecting it on the epipolar direction assuming a known plume direction thus improving the height measurement precision we apply the method to landsat 8 data taking into account the specificities of the focal plane modules we focus on the holuhraun 2014 fissure eruption iceland we validate our measurements against ground based measurements the method has potential for detailed high resolution routine measurements of volcanic plume height velocity the method can be applied both to other multifocal plane modules push broom sensors such as the esa sentinel 2 and potentially to other push broom systems such as the cnes spot family and pleiades

modified newmark model for seismic displacements of compliant slopes newmark sliding block analyses are widely used for estimation of permanent displacements of slopes in earthquakes the conventional newmark model however neglects the dynamic response of the material above a potential failure surface decoupled procedures have been developed to account for that response but they neglect the effects of permanent displacements on the response a modified newmark analysis that considers the dynamic response including the effects of permanent displacements of the material above the failure surface is presented the modified newmark analysis shows that the decoupled approach produces somewhat conservative estimates of permanent displacements for stiff and or shallow failure masses but that it may produce unconservative estimates for failure masses that are soft and or deep many slopes of large lined landfills may fall into this latter category the notion of a slope spectrum which illustrates the effect of the natural period of a potential failure mass on permanent slope displacement is also introduced

mt etna sulfur dioxide flux monitoring using aster tir data and atmospheric observations this work is aimed at estimating the sulfur dioxide emission of mt etna volcano sicily italy using the thermal infrared images remotely sensed by the advanced spaceborne thermal emission and reflection radiometer aster a new procedure named fun is presented based on approximating functions which represent the atmospheric terms of the radiative transfer equation transmittance up welling and down welling radiances the parameters of the approximating functions have been computed through the modtran simulations performed using atmospheric monthly mean profiles measured at trapani 1989 2003 trapani wmo station 16429 is located at the western tip of sicily and is the closest station to mt etna volcano with these functions modtran is no longer necessary to compute the so2 abundance in the plume emitted from mt etna and seen by aster only an atmospheric radiosounding and a digital elevation model dem registered to the aster image are required this new procedure is compared with the known look up tables lut procedure proposed by other authors an interesting aspect of the fun procedure derives from its combined use with a split window sw algorithm in this case only radiosounding is required to compute the so2 map the fun procedure presented in this paper is a rapid simple and accurate means of generating so2 map estimates from the aster view of mt etna the proposed scheme can easily be adapted to another sensor and another volcano in this paper the results from two aster images 19 july 2003 and 29 july 2001 are presented in

first indications of the formation of kerogen amorphous fractions by selective preservation role of non hydrolysable macromolecular constituents of eubacterial cell walls abstract two marine kerogens supposed to contain an important bacterial component were analysed and their spectroscopic and pyrolytic features compared with those of the amorphous non hydrolysable macromolecular materials bacterans isolated from extent bacteria examination by transmissio electron microscopy revealed that dontrien lower toarcian shales paris basin is essentially composed of amorphous organic matter and osb3 marl slate formation n e england is exclusively amorphous the formation upon kerogen pyrolysis of series of products 3 methylalkanes dimethylalkanes ethylesters and alcohols characteristic of bacteran pyrolysates is consistent with the contribution of bacterans to the formation of these two kerogens the nature and distribution of the acids of the pyrolysates indicate that bacterial biomass was implicated in osb3 and dontrien kerogen formation via two pathways bacteran selective preservation and incorporation of partly degraded lipids comparison between dontrien and osb3 indicates a weaker contribution of the selective preservation pathway to osb3 kerogen whereas bacteria lipid incorporation may have been more significant in osb3 kerogen the selective preservation pathway was so far considered as restricted to the formation of kerogens having retained some of the morphological features of the source organisms an important point derived from this study is therefore the ability of this pathway to also contribute to the formation of amorphous kerogens

methods for assessing the stability of slopes during earthquakes a retrospective abstract during the twentieth century several methods to assess the stability of slopes during earthquakes were developed pseudostatic analysis was the earliest method it involved simply adding a permanent body force representing the earthquake shaking to a static limit equilibrium analysis stress deformation analysis a later development involved much more complex modeling of slopes using a mesh in which the internal stresses and strains within elements are computed based on the applied external loads including gravity and seismic loads stress deformation analysis provided the most realistic model of slope behavior but it is very complex and requires a high density of high quality soil property data as well as an accurate model of soil behavior in 1965 newmark developed a method that effectively bridges the gap between these two types of analysis his sliding block model is easy to apply and provides a useful index of co seismic slope performance subsequent modifications to sliding block analysis have made it applicable to a wider range of landslide types sliding block analysis provides perhaps the greatest utility of all the types of analysis it is far easier to apply than stress deformation analysis and it yields much more useful information than does pseudostatic analysis

source and significance of selected polycyclic aromatic hydrocarbons in sediments hovea 3 well perth basin western australia spanning the permian triassic boundary abstract stable carbon isotopic data for polycyclic aromatic hydrocarbons pahs chrysene and triphenylene benzo e pyrene 9 methylphenanthrene in sediments of comparable thermal maturity from a petroleum drill core hovea 3 well perth basin western australia spanning the largest mass extinction event in the past 500 million years permian triassic boundary are consistent with an algal kerogen source in the basal triassic as opposed to a combustion and or higher plant source in the underlying permian sediments the 13c values of extractable pahs are less negative in the permian inertinitic interval 24 7 to 29 2 than the triassic sapropelic interval 30 to 33 3 a strong correlation is evident between 13c of individual pahs 13c of kerogen and rock eval pyrolysis hydrogen index providing unequivocal evidence that pah 13c is mainly controlled by organic matter type abundant algal derived pahs in basal triassic sediments may be a global feature the lack of coal globally in the basal triassic sediments is also consistent with this observation the early triassic coal gap appears to coincide with the global extinction of peat forming plants at the end of the permian coal did not reappear until the middle triassic and permian levels of plant diversity and thick peat deposits did not recover until the late triassic the pah isotopic data support the contention that a global anoxic event at the end of the permian period contributed to the gradual worldwide asphyxiation and ultimate extinction of many marine and terrigenous organisms

the organic geochemistry of coal from plant materials to coal coalification is a process that transforms plant remains under the influence of time temperature and possibly pressure to a black generally lustrous solid organic fossil fuel having a very complex chemistry although much has been learned in the past two centuries on coal chemistry we still have little knowledge of the way plant materials undergo these transformations the problem has been the existence of adequate characterization tools the advent of some new tools for structural elucidation of macromolecules has led to some revised thinking on coalification originally thought to be a process involving the full degradation of plant remains and subsequent reconstitution of these remains the general consensus today is that the process involves a selective preservation of certain resistant plant components followed by some minor reorganization of the biopolymers that survive the major components of plants do degrade and the resistant ones often constitute only a small fraction of the original mass of the plant materials this paper examines the most recent literature concerning coalification and focuses on the chemistry associated with coalification of certain recognizable plant remains that have been at the center of research activity for the past two decades thus we examine the recent knowledge of the chemistry of resistant biopolymers in extant and fossil wood cuticles resins spores and algae knowledge that has been assembled to establish the reaction pathways towards coal macromolecules

lateral spreading within a limit equilibrium framework newmark s sliding blocks with degrading yield accelerations lateral spreading is a prevalent geotechnical problem associated with earthquake induced liquefaction often occurring at gentle slopes of loose saturated sand near bodies of water and causing sig

assessment of earthquake induced landslide hazard in greece from arias intensity to spatial distribution of slope resistance demand abstract the earthquake induced landslide hazard in greece is evaluated by means of a parametric time probabilistic approach first by taking into account the characteristics of seismicity affecting greece we calculated occurrence probabilities for different levels of seismic shaking expressed in terms of arias intensity for a time interval of 50 yrs then by utilizing the linkage of newmark displacement with arias intensity and critical acceleration we mapped the spatial distribution of the slope strength demand that imply a 10 probability that displacement will exceed critical thresholds for potential seismic triggering of incoherent and coherent landslides the obtained results suggest that the areas of western greece and the broader region of the gulf of corinth are the most exposed to conditions of seismic triggering of both kinds of landslides the derived slope strength demand maps could provide the basis for the assessment of whether particular slopes have a significant failure probability by comparing the estimated strength demand with the actual critical acceleration values calculated from slope material properties and slope angle we exemplified this approach at a coastal area of the western gulf of corinth where by considering situations expected in dry and wet periods we also demonstrated that earthquake effects on slope stability depend on the season of earthquake occurrence

theoretical study on volcanic plume hbox so _ 2 and ash retrievals using ground tir camera sensitivity analysis and retrieval procedure developments in this paper a sensitivity analysis and procedure development for volcanic plume sulfur dioxide and ash retrievals using ground thermal infrared camera have been carried out the semiconductor device camera considered as a reference has a spectral range of 8 14 m with noise equivalent temperature difference that is better than 100 mk at 300 k the camera will be used to monitor and assess the hazards of mt etna volcano to mitigate the risk and impact of volcanic eruptions on the civil society and transports a minimum number of filters have been selected for sulfur dioxide so2 and volcanic ash retrievals the sensitivity study has been carried out to determine the so2 and volcanic ash minimum concentration detectable by the system varying the camera geometry and the atmospheric profiles results show a meaningful sensitivity increase considering high instrument altitudes and low camera elevation angles for all geometry configurations and monthly profiles the sensitivity limit varies between 0 5 and 2 g m 2 for so2 columnar abundance and between 0 02 and 1 for ash optical depth two procedures to detect so2 and ash based on the least square fit method and on the brightness temperature difference btd algorithm respectively have also been proposed results show that high concentration of atmospheric water vapor columnar content significantly reduces the ash plume effect on the btd a water vapor correction procedure introduced improves the ash retrievals and the cloud discrimination in every season considering all the camera geometries

effects of oxidative weathering on the composition of organic matter in coal and sedimentary rock abstract the effect of oxidative weathering on the composition of sedimentary organic matter som of lignite subbituminous coal quartzose arenite siliceous mudstone siliceous shale and diatomaceous shale was investigated in hokkaido japan in a subarctic humid climate for 15 samples in total a humic substance extraction method was applied to divide som into lipid c humin c and alkali soluble c the alkali soluble c was further divided into fulvic acid fa c humic acid ha c and a smaller molecular size fraction smsf c which comprised organic molecules able to pass through a dialysis membrane

seismic triggering of catastrophic failures on shear surfaces in saturated cohesionless soils this paper is concerned with an analysis of the seismic performance of infinite slopes in undrained conditions the material assumed on the sliding surface is a loose saturated sand susceptible to a gradual loss in undrained shear strength after failure with the progress of unidirectional shear displacement the undrained monotonic and cyclic shear behavior of this sand was investigated through an experimental study based on ring shear tests with initial stresses corresponding to the static conditions on the sliding surface of the analyzed slopes these tests provide the experimental framework for a modified sliding block method to estimate the earthquake induced undrained shear displacements for conditions of no shear stress reversals on the sliding surface the proposed estimation procedure incorporates the shearing resistance obtained from undrained monotonic ring shear tests to approximate the undrained yield resistance at a certain displacement during an earthquake the term catastrophic failure is

uncertainty in seismic slope deformation model predictions in this article we examine how variability in driving and resisting force parameters together translate into uncertainty in seismic slope deformation predictions predictive uncertainty of the newmark rigid block and makdisi seed decoupled deformation based methods was evaluated by performing a series of probabilistic monte carlo simulations for two idealized slope models results from these analyses demonstrate that the highly non linear relationship between acceleration ratio and displacement associated with the deformation models dictates the way in which parametric variability is propagated through the analysis and can lead to varying degrees of uncertainty in the deformation predictions based on this observation three zones along the displacement acceleration ratio relationship were identified according to their relative degree of non linearity and correlated with their relative influence on predictive uncertainty these are i highly uncertain ii moderately uncertain and iii low uncertainty using this framework the widely held notion of a generic order of magnitude estimate for deformation predictions is a misnomer based on this it is recommended that realistic levels of parametric variability be incorporated in the seismic slope deformation analysis to establish the operating conditions of the slope system slopes identified as highly uncertain or moderately uncertain require a more robust probabilistic analyses to meaningfully interpret poorly constrained deformation predictions

the molecular composition of kerogen in pliocene mediterranean sapropels and associated homogeneous calcareous ooze abstract the organic matter of three time equivalent pliocene sapropels was characterized as being predominantly type ii kerogen using rockeval pyrolysis it is dominated by amorphous organic matter originating mainly from marine organisms as indicated by the relatively high abundances of algaenan and chlorophyll derived pyrolysis products in the curie point pyrolysates of the kerogen of the sapropels however a small amount of terrigenous organic matter was also observed in the form of pollen and spores that most probably yielded the oxygenated aromatic pyrolysis products known to derive from sporopollenin lignin pyrolysis products such as methoxyphenol and catechol 1 2 benzenediol commonly used as unequivocal evidence for a contribution of terrestrial higher plants in the form of woody material to the kerogen were absent from the kerogen pyrolysates no major spatial and temporal differences in the kerogen composition of the three time equivalent sapropels were observed palynological studies revealed that organic matter in the homogeneous intervals below and above the sapropels consisted of pollen spores and amorphous organic matter this was confirmed by curie point pyrolysis gc ms results showing a relatively high abundance of algaenan derived compounds and the presence of oxygenated aromatic pyrolysis products the differences observed between the kerogen pyrolysates of the sapropels and their homogeneous intervals are suggested to be governed primarily by enhanced preservation conditions resulting in increased preservation of marine organic matter in the sapropels

the use of multispectral thermal infrared image data to estimate the sulfur dioxide flux from volcanoes a case study from mount etna sicily july 29 1986 the authors have found that image data acquired with nasa s airborne thermal infrared multispectral scanner tims can be used to make estimates of the so sub 2 content of volcanic plumes tims image data are most applicable to the study of partially transparent so sub 2 plumes such as those released during quiescent periods or nonexplosive eruptions the estimation procedure is based on the lowtran 7 radiative transfer code which the authors use to model the radiance perceived by tims as it views the ground through an so sub 2 plume the input to the procedure includes the altitudes of the aircraft and ground the altitude and thickness of the so sub 2 plume the emissivity of the ground and altitude profiles of the atmospheric pressure temperature and relative humidity they use the tims data to estimate both ground temperatures beneath a plume and so sub 2 concentrations within a plume applying this procedure to tims data acquired over mount etna sicily on july 29 1986 the authors estimate that the so sub 2 flux from the volcano was approximately 6700 t d sup minus 1 the use of tims to study so sub 2 plumes represents a bridge between highly localized methods such as correlation spectroscopy or directmore sampling and small scale mapping techniques involving satellite instruments such as the total ozone mapping spectrometer or microwave limb sounder the authors require further airborne experiments to refine their estimation procedure this refinement is a necessary preparation for the scheduled 1998 launch of the advanced spaceborne thermal emission and reflectance radiometer which will allow large scale multispectral thermal infrared image data to be collected over virtually any volcano on earth at least once every 16 days less

regression models for estimating coseismic landslide displacement newmark s sliding block model is widely used to estimate coseismic slope performance early efforts to develop simple regression models to estimate newmark displacement were based on analysis of the small number of strong motion records then available the current availability of a much larger set of strong motion records dictates that these regression equations be updated regression equations were generated using data derived from a collection of 2270 strong motion records from 30 worldwide earthquakes the regression equations predict newmark displacement in terms of 1 critical acceleration ratio 2 critical acceleration ratio and earthquake magnitude 3 arias intensity and critical acceleration and 4 arias intensity and critical acceleration ratio these equations are well constrained and fit the data well 71 br 2 b88 but they have standard deviations of about 0 5 log units such that the range defined by the mean one standard deviation spans about an order of magnitude these regression models therefore are not recommended for use in site specific design but rather for regional scale seismic landslide hazard mapping or for rapid preliminary screening of sites 2007 elsevier b v all rights reserved

chemical evidence of kerogen formation in source rocks and oil shales via selective preservation of thin resistant outer walls of microalgae origin of ultralaminae abstract new structures termed ultralaminae were recently observed by transmission electron microscopy usually in high amounts in a number of kerogens from oil shales and source rocks morphological similarities were noted between ultralaminae and the thin ca 15 nm resistant outer walls composed of non hydrolyzable macromolecules algaenans commonly occurring in extant chlorophyceae especially in the cosmopolitan genus scenedesmus identification of the pyrolysis products of s quadricauda algaenan showed i a highly aliphatic structure based on a macromolecular network of long up to c32 polymethylenic chains probably cross linked by ether bridges and ii a close correlation based on the formation of n alkylnitriles between this algaenan and two ultralaminar kerogens the rundle oil shale mainly composed of ultralamina accumulations and the green river shale ultralaminae dispersed within an amorphous matrix these fossil ultralaminae therefore likely originated from the selective preservation of the thin algaenan containing outer walls of scenedesmus and or of other chlorophyceae containing outer walls of a similar morphology and composition relative distributions of n alkylnitriles and of n alkanoic acids in the pyrolysates of s quadricauda algaenan and of the rundle oil shale indicated that nitriles are not derived from secondary reactions of carboxylic acids but originate from preexisting nitrogen functions likely amides previous evidence of kerogen formation via selective preservation of algaenans was restricted to rather uncommon kerogens the present results added to ultralamina common occurrence and abundance point to a wide involvement and to a large contribution of the selective preservation of algaenan containing thin outer walls of chlorophyceae in the formation of kerogens in a number of lacustrine source rocks and oil shales all the available information suggest that the three way correlation selective preservation of algaenans from thin resistant chlorophycean outer walls formation of fossil ultralaminae presence of n alkylnitriles with a typical distribution in the pyrolysates of ultralaminar kerogens observed in this study might be of a general character

origin of low molecular weight alkylthiophenes in pyrolysates of sulphur rich kerogens as revealed by micro scale sealed vessel pyrolysis abstract micro scale sealed vessel mssv pyrolysis experiments have been conducted at temperatures of 150 200 250 300 330 and 350 c for various times on a thermally immature type ii s kerogen from the maastrichtian jurf ed darawish oil shale jordan in order to study the origin of low molecular weight lmw alkylthiophenes these experiments indicated that the lmw alkylthiophenes usually encountered in the flash pyrolysates of sulphur rich kerogens are also produced at much lower pyrolysis temperatures i e as low as 150 c as the major apart from hydrogen sulfide sulphur containing pyrolysis products mssv pyrolysis of a long chain alkylthiophene and an alkylbenzene indicated that at 300 c for 72 h no cleavage leading to generation of lmw alkylated thiophenes and benzene occurs in combination with the substantial production of lmw alkylthiophenes with a linear carbon skeleton at these conditions this indicated that these thiophenes are predominantly formed by thermal degradation of multiple poly sulfide bound linear c 5 c 7 skeletons which probably mainly originate from sulphurisation of carbohydrates during early diagenesis lmw alkylthiophenes with linear carbon skeletons seem to be unstable at mssv pyrolysis temperatures of 330 c either due to thermal degradation or to methyl transfer reactions lmw alkylthiophenes with a branched carbon skeleton most likely derive from both multiple poly sulfide bound branched c 5 c 7 skeletons and alkylthiophene units present in the kerogen

microbial transformations of organic matter in black shales and implications for global biogeochemical cycles abstract the various roles that microorganisms play in transformation of organic matter in geologic environments are yet to be fully revealed many of these roles influence and perhaps control the composition of earth s atmosphere over geologic time by directly impacting global scale cycling of carbon dioxide oxygen and methane one example is the weathering of black shales exposure of organic matter rich sedimentary rocks to oxygenated earth surface conditions results in significant changes in outcrop scale rock geochemistry with implications for element cycling on a global scale this article reviews the progress of ongoing research of a black shale weathering profile exposed near clay city kentucky usa using tools of molecular biology microbial ecology isotope geochemistry and organic geochemistry this research explores the role of microorganisms in utilization and oxidation of sedimentary organic matter and sulfide mineral oxidation and examines the communities of microorganisms that may live in this environment from this and related studies we are developing greater awareness of the importance of microorganisms in transfer of organic materials among various reservoirs of the geosphere biosphere hydrosphere and atmosphere

so2 flux measurements at mount etna sicily since 1987 over 220 measurements of the so2 flux at mount etna have been carried out using a correlation spectrometer cospec with different measuring techniques mainly with cospec mounted on a ground based vehicle this paper reports and analyzes the data obtained between october 1987 and december 1991 during this period three distinct time intervals characterized by particular so2 emission patterns were identified the first interval a showed a mean so2 flux of 5500 t d associated with relatively quiet summit crater eruptive activity the second interval b included two eruptive periods september october 1989 and january february 1990 associated with high fluxes reaching 10 000 25 000 t d the third interval c started in concert with a regional earthquake december 13 1990 and showed first a decrease and then an increase of so2 emissions before the onset of the major 1991 1993 flank eruption analysis of the data reveals a cyclic pattern to the so2 emissions over prolonged periods a nearly constant supply of so2 from the volcano s main feeder system especially evident in the long term a two to fivefold increase above mean flux values from 10 000 to 25 000 t d when occurring with paroxysmal eruptive activity and minimal flux values 1000 t d about 1 month prior to important eruptive events

simplified procedure for estimating earthquake induced deviatoric slope displacements a simplified semiempirical predictive relationship for estimating permanent displacements due to earthquake induced deviatoric deformations is presented it utilizes a nonlinear fully coupled stick slip sliding block model to capture the dynamic performance of an earth dam natural slope compacted earth fill or municipal solid waste landfill the primary source of uncertainty in assessing the likely performance of an earth waste system during an earthquake is the input ground motion hence a comprehensive database containing 688 recorded ground motions is used to compute seismic displacements a seismic displacement model is developed that captures the primary influence of the system s yield coefficient ky its initial fundamental period ts and the ground motion s spectral acceleration at a degraded period equal to 1 5 ts the model separates the probability of zero displacement i e 1 cm occurring from the distribution of nonzero displacement so that very low values of calculated

accumulation of organic matter in the kimmeridge clay formation kcf an update fossilisation model for marine petroleum source rocks abstract a model for marine source rocks based on previous microtextural and molecular characterisation of the immature organic matter from the kcf uk is developed illustrating the relationship between the type of primary producers the nature of organic matter metabolisable or bioresistant delivered to the sedimentary environment and the mechanisms of organic matter fossilisation the fossilisation occurs because one of the following factors prevails a the inherited bioresistant character of the initial organic matter in the case of i a selective preservation sensustricto when both the biological structure and the molecular composition are well preserved and ii a re organisation of resistant bio macromolecules selectively preserved when only the molecular composition is conserved b the acquisition of bioresistance as in the case of iii natural vulcanisation which produces a homogeneous and nanoscopically amorphous organic matter the latter is hydrogen rich and its genesis depends on the rate of delivery of metabolisable organic matter to the oxic anoxic boundary this is determined by primary productivity controlled sinking rates and as a consequence by the occurrence in bottom waters of conditions promoting a prolific growth of sulphate reducers along with a somewhat limited supply of iron so that h 2 s is not entirely trapped as pyrite c the accumulation of hydrogen rich organic matter in such source rocks is not only due to the phytoplanktonic and micro algal origin of natural bio macromolecules but also to sulphate reduction which protects a part of the oil potential of deposited organic matter

hydrocarbon biomarkers thermal maturity and depositional setting of tasmanite oil shales from tasmania australia this study represents the first geological and organic geochemical investigation of samples of tasmanite oil shale representing different thermal maturities from three separate locations in tasmania australia the most abundant aliphatic hydrocarbon in the immature oil shale from latrobe is a c19 tricyclic alkane whereas in the more mature samples from oonah and douglas river low molecular weight n alkanes dominate the extractable hydrocarbon distribution the aromatic hydrocarbons are predominantly derivatives of tricyclic compounds with 1 2 8 trimethylphenanthrene increasing in relative abundance with increasing maturity geological and geochemical evidence suggests that the sediments were deposited in a marine environment of high latitude with associated cold waters and seasonal seaice it is proposed that the organism contributing the bulk of the kerogen tasmanites occupied an environmental niche similar to that of modern sea ice diatoms and that bloom conditions coupled with physical isolation from atmospheric co2 led to the distinctive isotopically heavy 13c values 13 5 to 11 7 for the kerogen 13c data from modern sea ice diatoms 7 supports this hypothesis isotopic analysis of n alkanes in the bitumen 13 5 to 31 suggest a multiple source from bacteria and algae on the other hand the n alkanes generated from closed system pyrolysis of the kerogen 15 are mainly derived from the preserved tasmanites biopolymer algaenan the tricyclic compounds mean 8 both in the bitumen and pyrolysate have a common precursor they are consistently enriched in 13c compared with the kerogen and probably have a different source from the n alkanes the identification of a location where the maturity of the tasmanite oil shale approaches the oil window raises the possibility that it may be a viable petroleum source rock

carbon isotopic evidence for the origin of macromolecular aliphatic structures in kerogen abstract this study describes compound specific stable carbon isotopic analyses of aliphatic hydrocarbon products from flash pyrolysis 800 c 20 s of kerogens representing a range of depositional environments marine estuarine lacustrine and ages recent to ordovician the carbon isotopic measurements were obtained using isotope ratio monitoring gas chromatography mass spectrometry irmgc ms for the major aliphatic pyrolysis products n hydrocarbons acyclic isoprenoids and hopanoids while isotopic compositions of n hydrocarbons varied substantially between samples average values ranged from 35 to 14 0 00 values of n alkenes and n alkanes generated from a given sample generally ranged over less than 3 0 00 this isotopic uniformity implies a common origin for n hydrocarbons probably from thermal dissociation of biopolymers supporting the concept of selective preservation of highly resistant aliphatic structures in kerogens there are notable exceptions to this general relationship in which either mixed biopolymeric sources e g guttenberg fm or minor contributions from aliphatic biopolymers e g monterey must be inferred in several cases average n hydrocarbon values also closely match the corresponding total organic carbon toc value indicating that the n hydrocarbons in these samples are derived from structurally important or at least isotopically representative constituents of the kerogen in other samples significant discrepancies were observed between the values for these products and 13ctoc in these cases the presence of additional components not yielding hydrocarbons on pyrolysis is indicated isotopic compositions of isoprenoid hydrocarbons varied non systematically relative to those of n hydrocarbons whereas hopanoid hydrocarbons were consistently depleted in 13c relative to both toc and n hydrocarbons with values as low as 50 0 00

sulfur dioxide flux estimation from volcanoes using advanced spaceborne thermal emission and reflection radiometer a case study of miyakejima volcano japan abstract a method is described for estimating the two dimensional spatial distribution of volcanic so2 using thermal infrared image data acquired by the advanced spaceborne thermal emission and reflection radiometer aster the author proposes a new method to estimate wind velocity and plume height using an along track stereoscopic pair image volcanic so2 flux can be estimated from the spatial distribution of so2 and wind velocity since aster has both the thermal infrared radiometer tir and stereoscopic viewing function in the along track direction the volcanic so2 flux can be estimated from the aster data alone these methods are applied to the miyakejima volcano japan the so2 flux derived from aster is around 5 104 ton day 580 kg s 1 which is slightly larger than the value derived from cospec the plume height estimation error may cause this disagreement because the so2 estimation procedure is very sensitive to the plume height

shaking table modeling of seismically induced deformations in slopes physical model experiments were performed on a 1 g shaking table with the principal goals of 1 investigating the mechanisms of seismically induced permanent deformations in slopes and 2 assessing the accuracy and applicability of the newmark sliding block procedure for estimating seismically induced deformations in slopes each of the clayey slope models deformed in response to strong shaking with the principal mode of deformation being deep rotational translational sliding displacement deformations were principally focused along one or more highly localized shear surfaces though a significant amount of additional deformation was also distributed over a relatively wide region of the models the newmark analyses generally provided moderately accurate although somewhat unconservative estimates of deformations displacements computed using the rigid sliding block analysis ranged from 27 to 225 of maximum measured displacements and averaged about 75 of measured displacements for the test series the newmark type analyses were most reliable for those model tests that experienced large deformations where the sliding resistance was controlled principally by postpeak to residual strengths

structural and isotopic analysis of kerogens in sediments rich in free sulfurised botryococcus braunii biomarkers abstract type i kerogens of two relatively immature unusual hypersaline sediments with extracts rich in sulfurised botryococcus braunii b braunii biomarkers of miocene pliocene age from the sdom formation dead sea israel have been investigated using a variety of organic geochemical techniques py gc ms revealed a dominant homologous series of n alk 1 enes and n alkanes solid state 13c nmr and ft ir data are consistent with a large contribution of b braunii algaenan sem of the isolated kerogens showed a high degree of morphological alteration and the b braunii colonies were not recognisable the 13c values of the n alkanes and n alkenes in the pyrolysates from the kerogens were substantially lower than the 13c values of the bulk kerogens and other well defined b braunii biomarkers saponification of the kerogens released a series of c16 c34 fatty acids with an even over odd carbon number predominance dominated by the c22 and c28 homologues and in one of the kerogens similar 13c values as the pyrolysate n alkanes n alkenes of similar carbon number ruo4 treatment of the saponification residue released c16 to c34 fatty acids with an even odd carbon number predominance in the high molecular weight region maximising at c16 and c22 homologues also having comparable 13c values to the pyrolysate n alkanes of similar carbon number n 1 based on these data it is suggested that the off line pyrolysis products n alkanes and n alkenes have no association with either b braunii or its algeanan but are derived from other unspecified algae substantially more depleted in 13c the kerogen thus shows no morphological or molecular evidence for the preservation of b braunii algaenan despite the presence of its sulfurised biomarkers in the solvent extracts of these sediments it is suggested that b braunii that thrived during the formation of the sdom deposits may have exhibited both a high lipid content and a low algaenan content thus the lipids were efficiently preserved by sulfurization whereas the contribution of the algaenan to the kerogen was negligible

effects of near fault ground shaking on sliding systems a numerical study is presented for a rigid block supported through a frictional contact surface on a horizontal or an inclined plane and subjected to horizontal or slope parallel excitation the latter is described with idealized pulses and near fault seismic records strongly influenced by forward directivity or fling step effects from northridge kobe kocaeli chi chi aegion in addition to the well known dependence of the resulting block slippage on variables such as the peak base velocity the peak base acceleration and the critical acceleration ratio our study has consistently and repeatedly revealed a profound sensitivity of both maximum and residual slippage 1 on the sequence and even the details of the pulses contained in the excitation and 2 on the direction or in which the shaking of the inclined plane is imposed by contrast the slippage is not affected to any measurable degree by even the strongest vertical components of the accelerograms moreover the slippage from a specific record may often be poorly correlated with its arias intensity these findings may contradict some of the prevailing beliefs that emanate from statistical correlation studies the upper bound sliding displacements from near fault excitations may substantially exceed the values obtained from some of the currently available design charts

nested newmark model to calculate the post earthquake profile of slopes abstract the newmark sliding block approach is a common means of evaluating permanent displacements of slopes undergoing seismic loading however the conventional newmark approach omits the presence of multiple shear zones or regions of dispersed shear movement the occurrence of these shear movements within slopes can often materialize with added vertical and lateral movements above the basal failure surface typically considered in the conventional newmark approach this study modifies the conventional newmark sliding block approach by discretizing a given slope into a series of nested critical failure wedges each with an associated yield acceleration termed a nested newmark model nnm use of the nnm enables assessment of a post earthquake slope profile within a limit equilibrium framework based on the integration of relative displacements from the toe to the crest the results demonstrate a different response than conventional newmark approaches the model outputs can account for the restriction of toe movements as well as heaving and slumping behavior of the slope face and crest respectively larger seismic excitation resulted in further destabilization of nested wedges near the crest the presented approach establishes a framework that can be extended to any type of failure geometry or series of failures including rotational geometry these results are compared to a numerical model which exhibit similar behavior this framework is conceptual but builds upon the well accepted newmark sliding block approach to provide an alternative means of assessing post earthquake slope movements

kerogen origin evolution and structure kerogen commonly defined as the insoluble macromolecular organic matter om dispersed in sedimentary rocks is by far the most abundant form of om on earth this fossil material is of prime importance as the source of oil and natural gas moreover kerogen can provide essential information on major topics such as past environments climates and biota this review reports the main advances in kerogen studies since the comprehensive synthesis edited by durand durand b ed kerogen insoluble organic matter from sedimentary rocks editions technip paris 1980 it is organized into eight sections the first two are concerned with the successive definitions of kerogen and the definition used here the different techniques used for kerogen isolation without loss or degradation and basic kerogen analysis the third and fourth focus on sedimentary om sources and preservation processes in relation to depositional environment including sedimentation conditions favourable for kerogen accumulation and extrapolation to past geological time great strides have been made in the latter topics over the last 25 years owing to a combination of classical studies in organic geochemistry and studies in other domains such as biogeochemistry oceanography hydrology and soil science along with the development of powerful analytical tools the next two sections deal with the different kerogen classifications by type and kerogen evolution and maturation upon burial in sediments structural modelling of coal and kerogen based on physical and or chemical structural analysis is described in the following section although only statistical the models thus derived provide a synthetic view of the main structural resemblances and differences among various samples in relation to source maturity or physicochemical properties finally the last section explores some of the advances in kerogen understanding expected for the near future the review includes a list containing about 500 references

nonlinear coupled seismic sliding analysis of earth structures earthquake induced sliding displacements of earth structures are generally evaluated using simplified sliding block analyses that do not accurately model the seismic response of the sliding mass nor the seismic forces along the slide plane the decoupled approximation introduced to capture each of these effects separately is generally believed to be conservative however recent studies using linear viscoelastic sliding mass models have revealed instances where the decoupled approximation is unconservative in this paper a coupled analytical model that captures simultaneously the fully nonlinear response of the sliding mass necessary for intense motions and the nonlinear stick slip sliding response along the slide plane is presented the proposed sliding model is validated against shaking table experiments of deformable soil columns sliding down an inclined plane the effect of sliding on the response of earth structures is evaluated and comparisons are made between sliding displacements calculated us

stability analysis of slopes with ground water during earthquakes abstract heavy seismic damage tends to occur in embankments when ground water is present this paper proposes and applies a numerical procedure to evaluate slope stability during seismic loading seismic failure is herein defined to occur when a cumulative plastic deformation exceeds a critical value of deformation determined by static slope stability analysis the numerical procedure relies on finite element analysis of dynamic stress and deformation in slopes to assess their stability during earthquakes considering the effect of ground water level the performance of the proposed numerical procedure is assessed by applying it to evaluate the seismic slope stability of hypothetical and actual slopes affected by high ground water levels

deformation failure mechanism of saturated fill slopes due to resonance phenomena based on 1g shaking table tests earthquake motions include waves of various frequency bands ranging from low to high frequency notably the dominant frequency affects the seismic stability of fill slopes hence to analyze the d

reconstruction of so2 flux emission chronology from space based measurements abstract infrared satellite images measured with the modis instrument of the volcanic plume produced during the 2006 eruption of mt etna were analysed to produce maps of so 2 amount we used these maps to reconstruct time series of so 2 fluxes by integrating profiles of so 2 orthogonal to the plume advection direction and multiplying with wind speeds from a meteorological model these data were then compared with a reconstructed time series of so 2 fluxes measured with the flame ground based network of ultraviolet doas systems surrounding the volcano we found weak agreement on 3rd december when little ash was emitted but this agreement improved when a 0 3 m s 1 wind speed correction factor was used flame and modis results were in good agreement on the 6th december and improved when a 0 3 m s 1 offset was applied the corrected data revealed that the only period of time when flame and modis did not track together was coincident with the presence of ash which interferes with the ir imagery and retrieval of so 2 we highlight that combining two independent time series of so 2 flux allows a precise determination of wind speed if there is sufficient time dependent structure in the so 2 signal the observed increase in so 2 flux prior to the ash emission is interpreted as a quiescent release of an accumulated gas phase that drive eruptive activity as previously suggested for the southeast crater system of etna in this case the so 2 flux signal therefore acted as a precursor to the eruptive ash events this work demonstrates that quantitative reconstruction of so 2 flux time series is feasible using modis data opening a new frontier in the use of satellite data to interpret volcanic processes in particular in poorly monitored remote locations

dynamic stability analysis of jointed rock slopes using the dda method king herod s palace masada israel abstract a dynamic two dimensional stability analysis of a highly discontinuous rock slope is demonstrated in this paper the studied rock slope is the upper terrace of king herod s palace in masada situated on the western margins of the seismically active dead sea rift the slope consists of sub horizontally bedded and sub vertically jointed stiff dolomite blocks the dynamic deformation of the slope is calculated using a fully dynamic version of dda in which time dependent acceleration is used as input the analytically determined failure modes of critical keyblocks in the jointed rock slope are clearly predicted by dda at the end of the dynamic calculation it is found however that for realistic displacement estimates some amount of energy dissipation must be introduced into the otherwise fully elastic un damped dda formulation comparison of predicted damage with actual slope performance over a historic time span of 2000 years allows us to conclude that introduction of 2 kinetic damping should suffice for realistic damage predictions this conclusion is in agreement with recent results of tsesarsky et al in y h hatzor ed stability of rock structures proceedings of the fifth international conference of analysis of discontinuous deformation balkema publishers lisse 2002 pp 195 203 who compared displacements of a single block on an inclined plane subjected to dynamic loading obtained by dda and by shaking table experiments using dynamic dda it is shown that introduction of a simple rock bolting pattern completely stabilizes the slope

organic matter accumulation and preservation controls in a deep sea modern environment an example from namibian slope sediments the luderitz upwelling cell is presently the most productive area of the benguela current system and abundant organic matter om accumulates on the adjacent slope sediments even at great water depth om from two cores taken on the slope and covering the last 280 kyear was analysed in terms of petroleum quality rock eval chemical features ftir eds and petrographic composition light microscopy and tem these data indicate that the om is more oxidized at 3606 m water depth than on the upper slope sediments 1029 m although the petroleum quality of the om throughout the deep water core remains surprisingly high for hemipelagic deep sea sediments hi 200 400 mg g the petroleum quality of om accumulated on the upper slope is consistently high hi averages 450 mg g two petrographic types of om are distinguishable from microscopic observation each ascribed to distinctive preservation mechanisms 1 granular amorphous om which dominates in the deep water core is formed by organo mineral aggregates aggregation appears to be the primary preservation mode at this depth although is quantitatively limited maximum toc value of 4 wt of bulk sediment obtained through this process the ultrastructure of the aggregates highlights an intimate association pattern between sedimentary om and clays 2 gel like nannoscopically amorphous om naom largely dominates at 1000 m water depth and contains sulfur thus early diagenetic sulfurization was probably involved in the preservation of this om but a contribution from the classical degradation recondensation pathway cannot be ruled out moreover selective preservation occurred at both sites but represents an insignificant part of the om organic fluxes mainly control the occurrence and extent of sulfurisation at both water depths by determining the redox conditions at the sea floor aggregate formation is limited by both organic and mineral fluxes at the lower slope whereas om supply is never limiting on the upper slope although consistently operating through time at both depths preservation by organo mineral association is limited by mineral availability and thus accounts for a relatively minor portion of the om accumulated on this organic rich slope in the case of large organic fluxes sulfurisation and or degradation recondensation is required to obtain toc contents above 4 wt of bulk sediment in the area

study on a failed dip slope with a thin sandy layer in 2004 niigata ken chuetsu earthquake among the extensive failed slopes in the 2004 niigata ken chuetsu earthquake japan a dip slope at yokowatashi ojiya was investigated intensively the sliding plane was along a weak thin tuff sandy layer which had been deeply weathered triaxial compression tests and plane strain compression tests were performed on undisturbed specimens obtained by block sampling and boring sampling to evaluate the strength that was mobilized on the sliding plane stability analysis based on the test results reveals that at normal time without earthquake and without an extremely high groundwater level the slope is stable furthermore the calculation of earthquake induced displacement provides a reasonable simulation of the failure of this slope

organic matter in a low productivity anoxic intraplatform basin in the triassic tethys this paper presents isotopic bulk geochemical and biomarker data measured on organic matter accumulated in a narrow extensional basin developed at the oceanward margin of the huge triassic carbonate platform in the alps appenines domain the integration of isotope signatures organic petrographical and biomarker evidence together with the composition of kerogen pyrolysates suggests immature organic matter predominantly of algal origin with a minor but not negligible higher plant derived and moderate bacterial contribution for the entire sequence the mineral sources are dominated by platform derived subtidal dachstein limestone with a minor palaeosol input and a moderate contribution of autochtonous quartz nevertheless parallel variations observed in the mineral content as well as in the amount and the quality of the organic matter reflect variations in the palaeoenvironment the increased humidity existing in the period of the accumulation of the upper section of the sequence led to the restriction of dolomitization a slightly greater higher plant derived contribution in this section is evidenced by the composition of bitumen and the results on gc and gcims analyses on the non aromatic hydrocarbon fraction of bitumen moreover the climate induced weathering enchanced the primary productivity and resulted in a pronounced increase in the toc content the average estimated value of the planktonic productivity is about three times higher for the calcite rich sequence than the dolomite rich one being 44 2 and 15 3 tc org m 2 ma respectively the low to moderate planktonic productivity shows that anoxic conditions observed for the entire succession are a consequence of the stagnant water stratification rather than high planktonic productivity depth trends in the data measured on kerogens hi oi 13 corg values composition of pyrolysate together with the 18 o excursions and 13 c values appear to be controlled by sea level fluctuations consistent with the high abundance of alkyltiophenes in kerogen pyrolysates the high s org c ratios ranging between 0 05 and 0 10 suggest the importance of natural sulfurization in the formation of the sulfur rich type ii s kerogen occurring in all of the samples

inclined plane studies of the newmark sliding block procedure this study considers the shaking induced displacement and dynamic response of a rigid block and deformable columns of soil on an inclined plane this work demonstrates that because of the coupled d

organic carbon as a palaeoenvironmental indicator in the marine realm recent developments in biogeochemistry have made accessible all information currently known to be present in sedimentary organic compounds i e the carbon skeleton structure the positions of functional groups and stable carbon isotope ratios this combined information has strengthened the applications of sedimentary organic compounds as biomarkers and palaeoenvironmental indicators this review summarizes the most important biomarkers and their applications in reconstructing marine palaeoenvironments and processes the marine environment is characterized by the combined presence of specific compounds such as organic sulphur compounds dinosteroids 24 n propylsteroids even in trace amounts high amounts of c hbi hydrocarbons and the absence of long chain n alkanes with odd over even predominance bicadinanes and specific higher plant triterpenoids e g oleanane furthermore palaeoenvironmental conditions such as photic zone anoxia hypersalinity microbial sulphate reducing activity algal blooming palaeo upwelling and palaeo surface seawater temperature are indicated by molecular and or isotopic characteristics biomarkers from terrestrial sources are included because land derived organic matter is an important contributor to coastal and shallow marine environments a short case study within a holocene terrestrial marine setting florida bay usa is also presented to illustrate the reconstruction of transgressive regressive trends using selected organic compounds

formation of ultralaminae in marine kerogens via selective preservation of thin resistant outer walls of microalgae abstract transmission electron microscopy tem observations recently revealed the common occurrence of very thin lamellar structures termed ultralaminae in kerogens from source rocks and oil shales so far considered as amorphous ultralaminae in lacustrine kerogens were shown to derive from the selective preservation of the algaenans occurring in the very thin outer walls of various freshwater chlorophyceae the chemical correlation between such algaenans and fossil lacustrine ultralaminae was chiefly based on the production on pyrolysis of n alkylnitriles with a typical distribution bimodal maxima at c 28 and c 16 the origin of marine ultralaminae is investigated in this work to this end spectroscopic and pyrolytic studies were carried out on i the algaenan forming the very thin outer walls of nanochlorum eucaryotum an extant marine chlorophycea and ii two ultralaminae containing marine kerogens from the lower toarcian shales of paris basin fecocourt and bray a high contribution of polymethylenic chains probably linked via ehter bridges was observed in these bio and geopolymers furthermore on pyrolysis they afforded the same n alkylnitriles with the same distribution unimodal maximum at c 13 lack of c 17 compounds fossil ultralaminae in marine kerogens therefore derive from the selective preservation of the algaenan composed very thin outer walls of marine chlorophyceae such as n eucaryotum algaenans from marine and freshwater chlorophyceae and therefore marine and lacustrine ultralaminae should be characterized by sharply distinct n alkylnitrile distributions

can tilt tests provide correct insight regarding frictional behavior of sliding rock block under seismic excitation earthquake induced dip slope sliding or rock block sliding is usually analyzed using friction angles or friction coefficients measured at the sliding interface a tilt test is a convenient test for measuring the required friction angle however a tilt test is a test under static conditions and the applicability of measured friction parameters to analyze slopes under dynamic excitation requires further discussion this study conducts a static tilt test and a dynamic shaking table test to simulate block sliding with base excitation compares differences in measured sliding thresholds and discusses the cause of these differences tests on three different materials aluminum sandstone and synthetic sandstone show that friction coefficients measured by tilt tests are always larger than the ones derived by shaking table tests moreover high frequency tests yield larger friction coefficients suggesting the sliding threshold is non constant under excitation in addition tests with varying normal stresses on the sliding block show that with increasing contact stresses sliding thresholds decrease implying that sliding threshold varies with normal stress instantaneous friction coefficients i t during sliding are also studied in this work it has been found that frictional behavior of synthetic sandstone deviates from the idealized coulomb friction model the instantaneous friction coefficient varies with relative displacement and relative velocity during sliding finally reasons for differences between a static tilt test and a dynamic shaking table test are discussed this study preliminarily identifies the limitations of the tilt test when applied to dynamic problems and concludes that realistic sliding thresholds can only be obtained using dynamic tests such as shaking table tests

satellite and ground observations of the june 2009 eruption of sarychev peak volcano matua island central kuriles after 33 years of repose one of the most active volcanoes of the kurile island arc sarychev peak on matua island in the central kuriles erupted violently on june 11 2009 the eruption lasted 9 days and stands among the largest of recent historical eruptions in the kurile island chain satellite monitoring of the eruption using moderate resolution imaging spectroradiometer meteorological agency multifunctional transport satellite and advanced very high resolution radiometer data indicated at least 23 separate explosions between 11 and 16 june 2009 eruptive clouds reached altitudes of generally 8 16 km above sea level asl and in some cases up to 21 km asl clouds of volcanic ash and gas stretched to the north and northwest up to 1 500 km and to the southeast for more than 3 000 km for the first time in recorded history ash fall occurred on sakhalin island and in the northeast sector of the khabarovsky region russia based on satellite image analysis and reconnaissance field studies in the summer of 2009 the eruption produced explosive tephra deposits with an estimated bulk volume of 0 4 km3 the eruption is considered to have a volcanic explosivity index of 4 because the volcano is remote there was minimal risk to people or infrastructure on the ground aviation transport however was significantly disrupted because of the proximity of air routes to the volcano