analysis of landslide frequencies and characteristics in a natural system coastal british columbia two hundred and one debris slides and debris ows were analyzed in a 286 km2 study area on the west coast of vancouver island british columbia canada the study area remains essentially untouched by humans and therefore affords a natural setting in which to examine slope processes landslides were identi ed and characterized on aerial photographs from 1 15 000 to 1 31 680 and were then mapped and transferred to a gis for analysis based on detailed landslide surveys we propose a new method to accurately determine volume of landslides of this type by measured total area results indicate average denudation rates of 56 m3 y 1 km 2 and higher natural rates of failure than analogous regions in coastal british columbia in contrast the landslide rates are substantially less than those from forested watersheds landslide distribution is spatially clustered in air photograph epochs and we propose intense storm cells within regional events as the causal mechanism further failures occurred preferentially over the west coast crystalline complex by 1 4 times a metamorphic assemblage of gabbros schists and amphibolites but 1 5 times less often over the island plutonic suite a granitic intrusive formation the former result represents a new nding while the latter corroborates ndings of previous authors we examined magnitude frequency relationships of the data set and present for the rst time a strong argument that the rollover effect is not merely an artefact but is instead a consequence of the physical characteristics of the landslides themselves we subsequently analyzed magnitude frequency relationships from two other complete data sets from coastal british columbia and produced a family of curves corroborating this result copyright 2004 john wiley sons ltd

logic tree approach for probabilistic tsunami hazard analysis and its applications to the japanese coasts for probabilistic tsunami hazard analysis ptha we propose a logic tree approach to construct tsunami hazard curves relationship between tsunami height and probability of exceedance and present some examples for japan for the purpose of quantitative assessments of tsunami risk for important coastal facilities a hazard curve is obtained by integration over the aleatory uncertainties and numerous hazard curves are obtained for different branches of logic tree representing epistemic uncertainty a ptha consists of a tsunami source model and coastal tsunami height estimation we developed the logic tree models for local tsunami sources around japan and for distant tsunami sources along the south american subduction zones logic trees were made for tsunami source zones size and frequency of tsunamigenic earthquakes fault models and standard error of estimated tsunami heights numerical simulation rather than empirical relation was used for estimating the median tsunami heights weights of discrete branches that represent alternative hypotheses and interpretations were determined by the questionnaire survey for tsunami and earthquake experts whereas those representing the error of estimated value were determined on the basis of historical data examples of tsunami hazard curves were illustrated for the coastal sites and uncertainty in the tsunami hazard was displayed by 5 16 50 84 and 95 percentile and mean hazard curves

comparing rockfall scar volumes and kinematically detachable rock masses scenario based risk assessment for rockfalls requires assumptions for different scenarios of magnitude volume the magnitude of such instabilities is related to the properties of the jointed rock mass with the characteristics of the existing unfavourably dipping joint sets playing a major role the critical factors for the determination of the maximum credible rockfall volume in a study site the forat negre in andorra are investigated the results from two previous analyses for the rockfall size distribution at this site are discussed the first analysis provides the observed size distribution of the rockfall scars and it is an empirical evidence of past rockfalls the second one calculates the kinematically detachable rock masses indicating hypothetical rockfalls that might occur in the future the later gives a maximum rockfall volume which is one order of magnitude higher because the persistence of the basal planes is overestimated the tension cracks and lateral planes interrupt systematically the basal planes exerting a control over their persistence and restricting the formation of extensive planes and large rockfall failures nonetheless the formation of basal planes across more than one spacings of tension cracks is possible and small step path failures have been observed too concluding the key factor for the determination of the maximum credible volume at the study site is the maximum realistic length of the basal planes penetrating into the rock mass their spacing and if applied the contribution of the rock bridges to the overall rock mass resistance

influence of soil cover on reducing the environmental impact of spontaneous coal combustion in coal waste gobs a review and new experimental data abstract the process of spontaneous combustion of coal and coal waste gobs including emitted gases condensation of inorganic and organic species in vents and leachable potential are examined in this study which encompasses a literature review and new experimental data furthermore the potential environmental benefits of cover soil reclamation for reduction of atmospheric and water leachable pollutant emissions are also considered the datong district shanxi province is one of the most important coal production areas in china the resulting large accumulations of mining waste are susceptible to spontaneous combustion three coal gangue dumps in the datong region subjected to a range of reclamation conditions were investigated to assess the influence on coal fires coal coal gangue and condensates from gaseous emissions were characterized in terms of chemical composition particle morphology mineralogy and leaching potential the condensates include tar like deposits elemental sulfur gypsum anhydrite ammonium and hg salts and a broad array of al k fe sulfates the latter may give rise to strongly acidic leachates with high metal loads which may pose a serious threat to the environment these findings led to the development of a proposed condensation sequence model for coal gangue fires the presence and distribution of organic compounds in the condensates deposited at vents were used as geothermometers in support of the proposed condensation model additionally the present study has also explored some feasible remediation measures it was found that covering these coal waste dumps with a layer of compacted soils appears to be an excellent cost effective method to reduce spontaneous combustion scavenge pollutants from gaseous emissions and minimize risks associated with the leaching of readily soluble salts condensed on the surface

the lower permian coal seams from singrauli coalfield m p india petrochemical nature rank age and sedimentation abstract biopetrographic and chemical investigations carried out on the lower permian barakar formation coal seams encountered in two bore holes ncsm 3 and cmsa 111 from the singrauli coalfield son valley reveal that they are in general rich in inertinite and mineral matter towards the eastern part whereas towards the western part they are rich in vitrinite with subordinate amounts of inertinite and mineral matter the turra and purewa top seams in the eastern part consist chiefly of mixed and fusic coal types and the turra and purewa merged seams in the western part of the basin are characterized dominantly by vitric and mixed coal types the basin of deposition was shallower in its major part but deepened towards west consequently frequent oxic fluctuations are most common in the coal seams of the eastern part the rank of these coal seams ranges between subbituminous a to high volatile bituminous c stages they show normal increase in rank with depth the coal seams in the western part of the area are higher in rank than their counterparts in the east the purewa bottom seam ncsm 3 is petro palynologically correlatable with the turra seam cmsa 111 of the western part it has been presumed that glossopteridophyta a complex group of gymnospermous plants arthrophytes and ferns were the vegetal source for the formation of barakar coal seams these plants during the early permian grew as thick forests along river valleys and as upland and subaquatic vegetation and experienced a warm humid and windy temperate climate the coal seams were presumably deposited in backwater and lacustrine swamps in fluvial environment from hypoauchthonous source material an attempt has been made to explain reasons for the high incidence of mineral matter and its apparent relationship with inertinite content in the coal seams while also discussing the depositional history

spontaneous combustion of the upper paleocene cerrejon formation coal and generation of clinker in la guajira peninsula caribbean region of colombia abstract clinker referred here as red and brick looking burnt rocks found interbedded in the upper paleocene cerrejon formation is the result of spontaneous and natural combustion of coal seams in the recent geologic past these rocks have been mapped measured and characterized in the cerrejon coal mine at la guajira peninsula colombia these burnt rocks usually outcrop in irregular patterns as almost tabular bodies up to 100 m thick thinning and pinching out below ground surface to depths up to 448 m mapping revealed that clinker is usually found near deformed zones either faults or tight folds timing of spontaneous combustion seems to predate folding and faulting but seems to postdate the development of the cerrejon thrust fault and alluvial fan proceeding from the perija range clinker covers an area of around 2 9 10 6 m 2 with a volume of approximately 1 4 10 8 m 3 the calculation of the amount of heat released through coal burning indicates that complete combustion of 6 4 mt of 26 4 10 6 j kg coal would yield 17 10 13 j

burning of coal waste piles from douro coalfield portugal petrological geochemical and mineralogical characterization abstract in the douro coalfield anthracites were exploited for decades 1795 1994 besides many small mines douro coalfield had two principal mining areas s pedro da cova and pejao coal mining activities cause several impacts on the environment one of which is the amount of discard or waste which was disposed of all over douro coalfield resulting in one of the most significant and severe impacts on the environment over 20 waste piles exist in the old mining areas geographically dispersed and three of them are presently burning their ignition was caused by forest fires during the summer of 2005 samples from the burning and unburned zones of the waste piles were studied as were the gas from vents and the minerals resulting after combustion geochemical processes and mineralogical transformations in the burning coal waste pile were investigated microscopic analyses of the samples identified some particular aspects related with combustion oxidation of pyrite the presence of iron oxides organic particles with cracks and rims with lowered suppressed rr devolatilization vacuoles and some char structures the occurrence of vitreous glassy material as well as fe al spinels in the burning coal waste provide evidences that the combustion temperature could have reached values above 1000 c due to combustion and as expected the samples studied reported high ash yields samples taken from the burning zones reported an increase of as cr li nb ni pb rb sr and lree concentrations and a decrease in zr and hree concentrations enrichment in cs li and rb was noted when comparing with the geochemical composition of black shales and world coals composition that is related with the contribution of granitic rocks in the sediments that originated the main lithologies of the douro coalfield carbonaceous shale and lithic arenites cluster analyses r type and q type were performed to understand the trend between the unburned and burning samples and it seems that some chemical variations are responsible for this separation elemental sulphur and salammoniac ammonium salt are the coal fire gas minerals neoformed on the surface of piles near the burning zones they were identified by different techniques mainly sem edx xrd and ftir relatively high concentrations of several aromatic compounds were detected in the gas collected at the studied areas as well as aliphatic hydrocarbons the highest concentrations of aromatic hydrocarbons were measured in gas samples from s pedro da cova waste pile the exposure to hazardous compounds present in the gas is a serious risk to human health and the environment

new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

potential for landsliding dependence on hyetograph characteristics 1 this paper examines the effect of hyetograph shape on the potential for landsliding in soil mantled landscapes an existing pore pressure response model iverson 2000 is used to study the effects of unsteady rainfall infiltration in hillslopes and the effect of slope and convergent topography is expressed using a steady state model of slope parallel subsurface flow slope stability is assessed using an infinite slope analysis this theoretical framework is coupled with simple hyetograph models and to intensity duration frequency functions to determine the return period of landslide triggering rainfall results also show that hyetographs with a peak at the end of a rainfall event have a stronger destabilizing effect than hyetographs with a constant rainfall or with a peak at the beginning of a storm thus the variability of hyetograph shapes adds uncertainty to the assessment of landsliding triggered by rainfall

susceptibility to spontaneous combustion of indian coals and lignites an organic petrographic autopsy abstract a critical analysis of various genetic and physical factors associated with certain early and late permian and oligocene coal seams and early eocene lignite seams of india revealed that the high secondary porosity and small particle size irrespective of petrographic and rank properties in sub humid climate favour spontaneous combustion large particle size high rates of gas emission and highly wet or dry seams in combination with each other tend to inhibit spontaneous heating in sub humid per humid and semi arid conditions the susceptibility to auto ignition of a coal or lignite seam is not uniform throughout its lateral extent and a high inherent porosity at any given rank stage and a high content of susceptible or oxidizable constituents are not sufficient to cause auto ignition however coal seams having high contents of exceedingly porous inertinite macerals become prone to spontaneous combustion in sub humid climate even without secondary porosity a scheme for indexing spontaneous combustion susceptibility based on the present study has been proposed which is particularly suited to the indian context

artificial neural network ensembles applied to the mapping of landslide susceptibility abstract this study proposes a comprehensive methodology to the application of an artificial neural network ensemble anne for the mapping of landslide susceptibility the identification of susceptible areas was performed on the basis of landslide inventory databases and seven parameters from three classes geomorphological elevation aspect slope topographic moisture index profile curvature geological lithology and environmental land use studies are presented for two major cities in brazil porto alegre and rio de janeiro as the main result we show that the susceptibility maps generated by the anne feature higher accuracy than those published by official organs such as the brazilian geological survey and geotechnical institute foundation geo rio this indicates that the proposed methodology can be an effective tool to assist the development of reliable landslide susceptibility maps in an efficient and agile manner

characterization and comparison of landslide triggering in different tectonic and climatic settings 1 the spatial and temporal distributions of landslides in six catalogues are analyzed in order to better understand landslide triggering mechanisms the six landslide catalogs are new zealand yosemite california grenoble french alps val d arly french alps australia and wollongong new south wales australia landslides are clustered in time for all catalogs for new zealand yosemite australia and wollongong the frequency of landslides varies between 1 and 1000 events per day and is well fitted by a power law there is no characteristic scale for daily rates when the large rates of daily landslides are known to be rain or earthquake triggered our results suggest the same triggering may hold for the small daily rates earthquakes are found to trigger landslides for the new zealand yosemite and australia areas at distances as large as 20 times their fault lengths there is no evidence of landslides triggered by earthquakes for the three other catalogs small m 4 earthquakes have little influence on landslide triggering if any for all catalogs for new zealand yosemite val d arly australia and wollongong the number of landslides per month is significantly correlated with monthly rainfall a correlation with temperature is found only for grenoble and new zealand landslide triggering strong clustering in time and space is more important in new zealand than in grenoble probably because the forcing seismicity and climate is stronger in new zealand than in the french alps but possibly also because of a high sensitivity to landslides in new zealand we suggest that intensity of clustering in space and time can be used to assess the importance of landslide triggering and the processes responsible for triggering

tsunami hazards along chinese coast from potential earthquakes in south china sea the pair of earthquakes off taiwan on december 26 2006 and the subsequent disruption of the internet traffic have called attention to the potential destructive hazards along the chinese coast from tsunamis historical records show past tsunami earthquakes in this region using gps earthquake focal mechanisms and geological evolution we have delineated the dangerous zones in the philippine sea plate where major earthquakes may occur the manila trench is identified as being most susceptible to future major earthquakes we have obtained the local gutenberg richter relationship for five sections along the philippine sea plate boundary and use this information for determining the probability distribution for tsunami waves of various heights to impinge on various chinese cities we devise a new method called the probabilistic forecast of tsunami hazard pfth which determines this probability distribution by direct numerical simulation of the waves excited by hypothetical earthquakes in these zones we have employed the linear shallow water equations over the south china sea we have also compared them with results from the nonlinear version and found that the linear treatment serves our purpose sufficiently well in the next century the probability of a wave with a height of over 2 0 m to hit near coast ocean of hong kong and macau is about 10 cities in taiwan are less vulnerable than those on the mainland coast 2007 elsevier b v all rights reserved

estimation of debris flow magnitude in the eastern italian alps the estimation of debris ow magnitude is an essential step in the assessment of debris ow hazard although different methods have been developed for the assessment of debris ow magnitude this is still a dif cult task because of the complexity of ow processes and the lack of data to test estimation procedures in many mountainous regions data on debris ow magnitude from 127 basins in the eastern italian alps have been collected from scienti c and technical journals technical reports historical documents gathered from local archives and eld surveys these data were used to develop and test different predictive approaches encompassing regression equations geomorphological surveys and probabilistic analysis of time series regression techniques were used to correlate debris ow magnitude to morphometric parameters and geological characteristics of the basins values of the channel debris yield rate contribution per unit length of channel proposed in the literature were compared with data from the study area for identifying reference values for channel stretches of different morphological characteristics although limited to the few basins in which suf cient data were available the probabilistic analysis of time series of debris ow magnitude provides indications about the relations between magnitude and frequency of debris ows some observations about the capability and drawbacks of considered methods are presented and the combined use of different approaches for the estimation of debris ow magnitude is suggested copyright 2004 john wiley sons ltd

the assessment of rockfall hazard at the base of talus slopes fragmental rockfall is characterized by the independent movement of individual rock fragments after detachment from a rock face the continued operation of the process leads to the accumulation of talus slopes on talus slopes the rockfall shadow extends beyond the base of the talus and consists of scattered boulders that have run out beyond the base of the slope the landing probability of boulders in the shadow is examined return periods of the order of 1000 years relative to a house site are typical rockfall behaviour particularly with respect to run out into the shadow can be assessed using geological evidence empirical methods physical modelling and computer based analytical models an empirical minimum shadow angle of 27 5 i e the angle between the distal limit of the shadow and the top of the talus slope is suggested and would be useful in rockfall vulnerability studies at the base of talus slopes as a first approximation to shadow limits it is preferable to the use of the rockfall fahrb

environmental characterization of burnt coal gangue banks at yangquan shanxi province china the environmental characteristics of coal gangue dumps in yangquan shanxi province china were investigated the amounts of coal gangue are very high in this coal region given the large coal production as a result widespread spontaneous coal gangue combustion gives rise to serious environmental problems coal gangue including bulk gangue and specific lithologies such as coal kaolinite rich material sandstone carbonate minerals and sulfide mineralizations fired coal gangue and condensate products from gas vents were fully characterized with respect to mineralogy chemistry and leaching potential the mineral paragenesis of the fired coal gangue cristobalite mullite hematite trydimite cordierite showed that the combustion temperature could reach 1200 c this was also corroborated by laboratory calcination tests during this combustion some elements such as c cl f s n as cd hg pb sn ge and se are emitted into the atmosphere however condensation processes accounted for the partial trapping of gaseous emissions of as s n hg and se thus condensate mineralizations of elemental sulfur and ammonium salts enriched in se as and other trace elements are frequent in the gas vents the leaching potential of trace elements in the fresh coal gangue was relatively low but the leaching of weathered coal gangue and the gas vents condensates could give rise to environmental problems as these materials produce acidic leachates and yield relatively high leachable levels of a number of elements

statistical evaluation of rockfall energy ranges for different geological settings of new south wales australia abstract structures used in rockfall protection are designed on the basis of the expected impact energy this quantity is usually assessed using commercial lumped mass models that stochastically predict possible block trajectories on a given slope in new south wales australia it is estimated that rockfall hazard involves values of energy which are much lower than those in europe canada or the usa however this view has not been supported by any systematic study across the whole state such a study is presented in this paper it applies to the five geological situations that are the most prone to rockfall in eastern australia previous experimental findings relating to block size distribution or restitution coefficients reviewed herein have been used to perform this statistical analysis a newly formulated lumped mass program which incorporates a relationship between the normal restitution coefficient and the impact angle allows the adoption of normal restitution coefficients in excess of unity for impact angles lower than 30 the results confirm that in three out of the five geological situations the 95th percentile of impact energy is lower than 200 kj and less than 2000 kj for the other two situations

a dynamic model for rainfall induced landslides on natural slopes assessment of landslide hazard often requires a good knowledge of the landslide characteristics and runout mechanics in this paper a quasi three dimensional model using lagrangian finite element method lfem is formulated to reproduce the dynamic runout process caused by landslides a case study of rainfall induced landslide on a natural slope in 1993 in lantau island hong kong is presented voellmy rheology is adopted to characterize the multi dimensional runout behaviour for engineering applications the selection of appropriate rheology and the determination of relevant key parameters associated with the failure mechanisms and runout mechanics are highlighted details of the mathematical formulation particularly with respect to the stability of the numerical scheme and quality control of the mesh are provided the close correlation between the calculation results and the field observations shows that if an appropriate rheological relationship is selected for the simulation a reasonable description of the runout behaviour can be obtained using the present model implications of the potential hazard from natural terrain landslides to downslope development are also discussed used in conjunction with geographical information system gis database the model can also be applied to the preliminary hazard zoning of terrain and land use management in mountainous areas

statistical analysis of rockfall volume distributions implications for rockfall dynamics we analyze the volume distribution of natural rockfalls on different geological settings i e calcareous cliffs in the french alps grenoble area and granite yosemite cliffs california sierra and different volume ranges i e regional and worldwide catalogs contrary to previous studies that included several types of landslides we restrict our analysis to rockfall sources which originated on subvertical cliffs for the three data sets we find that the rockfall volumes follow a power law distribution with a similar exponent value within error bars this power law distribution was also proposed for rockfall volumes that occurred along road cuts all these results argue for a recurrent power law distribution of rockfall volumes on subvertical cliffs for a large range of rockfall sizes 102 1010 m3 regardless of the geological settings and of the preexisting geometry of fracture patterns that are drastically different on the three studied areas the power law distribution for rockfall volumes could emerge from two types of processes first the observed power law distribution of rockfall volumes is similar to the one reported for both fragmentation experiments and fragmentation models this argues for the geometry of rock mass fragment sizes to possibly control the rockfall volumes this way neither cascade nor avalanche processes would influence the rockfall volume distribution second without any requirement of scale invariant quenched heterogeneity patterns the rock mass dynamics can arise from avalanche processes driven by fluctuations of the rock mass properties e g cohesion or friction angle this model may also explain the power law distribution reported for landslides involving unconsolidated materials we find that the exponent values of rockfall volume on subvertical cliffs 0 5 0 2 is significantly smaller than the 1 2 0 3 value reported for mixed landslide types this change of exponents can be driven by the material strength which controls the in situ topographic slope values as simulated in numerical models of landslides densmore et al 1998 champel et al 2002 index terms 5104 physical properties of rocks fracture and flow 1815 hydrology erosion and sedimentation 8122 tectonophysics dynamics gravity and tectonics

time represented by coal seams in the coal measures of england abstract the relationship between interseam sediment thickness and features of coal seams such as seam splits and partings are examined with respect to possible controls of sedimentation during the upper carboniferous in the lancashire coalfield england the coal seams are characterised by lateral changes mostly seam splits which take place across more or less straight boundaries with a northeast southwest trend explained as due to contemporary movement on buried faults during the time of peat formation some of the seam splits develop and thicken to the northwest others to the southeast interseam sediments generally reveal a patchy development in terms of thickness distribution and show little evidence of synsedimentary tectonism the apparent restriction of fault control to coal formation is explained by relatively slow accumulation rates of peat and therefore maximum exposure to the possibility of contemporary movement on underlying faults interseam sediments on the other hand represent relatively short episodes of deposition and so involved minimum exposure to control by contemporary fault movement

seismic monitoring of sechilienne rockslide french alps analysis of seismic signals and their correlation with rainfalls 1 in the french alps sechilienne rockslide is one of the natural phenomena that presents one of the highest levels of risk in terms of socioeconomical outcomes this rockslide has been active for a few decades and has been instrumented since 1985 the current very active volume of this rockslide is estimated to be up to 5 million m3 located on the border of a slowly moving mass reaching 50 100 million m3 the velocity of the most active zone reached 1 4 m yr in 2008 about twice the value of 2000 a seismic network was installed on this rockslide in may 2007 to supplement the monitoring system it has now recorded several thousand events mostly rockfalls but also hundreds of local and regional earthquakes which can be distinguished and classified from their signal characteristics rockfalls and microseismicity which occur in bursts of activity are found to be weakly but significantly correlated with rainfall rockfall occurrence increases linearly with precipitation with however strong fluctuations of the numbers of rockfalls per day for the same rainfall intensity no threshold was found for rainfall triggering with even 1 mm of rain being enough to trigger rockfalls rockfall activity starts almost immediately during a rainfall episode and lasts for several days after the rainfall rain also induces strong accelerations of the rockslide movement which also start quasi instantaneously and last for about a month

frequency and magnitude of debris flows on cheekye river british columbia abstract natural hazard and risk assessments are predicated on a detailed understanding of the relationship between frequency and magnitude of the hazardous process under investigation when information is sought from the deep past i e several thousand years continuous event records do not exist and the researcher has to rely on proxy data to develop the frequency magnitude f m model such work is often prohibitively expensive and few well researched examples for mass movement are available worldwide the cheekye fan is a desirable location for land development and has a depth and breadth of previous research unprecedented on any debris flow fan in canada we pursued two principal strains of research to formulate a reliable f m relationship the first focuses on stratigraphic analyses combined with radiometric dating and dendrochronology to reconstruct a comprehensive picture of holocene debris flow activity the second approach examines hydrological limitations of rock avalanche evolution into debris flows through either entrainment of saturated sediments or by failure of a landslide generated dam and upstream impoundment we thus hypothesize that debris flows from cheekye river can be separated into two quasi homogenous populations those that are typically triggered by relatively small debris avalanches slumps or rock falls or simply by progressive bulking of in stream erodible sediments and those that are thought to result from transformation of rock avalanches our work suggests that debris flows exceeding some 3 million m3 in volume are unlikely to reach the cheekye fan as a result of limited water available to fully fluidize a rock avalanche this analysis has also demonstrated that in order to arrive at reasonable estimates for the frequency and magnitude of debris flows on a complex alluvial fan significant multidisciplinary efforts are required without the significant precursor investigations and the additional efforts of this study life and property may be jeopardized or the design of debris flow mitigation may be subject to considerable and unquantifiable error

distribution of tsunami interevent times 1 the distribution of tsunami interevent times is analyzed using global and site specific hilo hawaii tsunami catalogs an empirical probability density distribution is determined by binning the observed interevent times during a period in which the observation rate is approximately constant the empirical distributions for both catalogs exhibit non poissonian behavior in which there is an abundance of short interevent times compared to an exponential distribution two types of statistical distributions are used to model this clustering behavior 1 long term clustering described by a universal scaling law and 2 omori law decay of aftershocks and triggered sources the empirical and theoretical distributions all imply an increased hazard rate after a tsunami followed by a gradual decrease with time approaching a constant hazard rate examination of tsunami sources suggests that many of the short interevent times are caused by triggered earthquakes though the triggered events are not necessarily on the same fault

modeling landslide recurrence in seattle washington usa abstract to manage the hazard associated with shallow landslides decision makers need an understanding of where and when landslides may occur a variety of approaches have been used to estimate the hazard from shallow rainfall triggered landslides such as empirical rainfall threshold methods or probabilistic methods based on historical records the wide availability of geographic information systems gis and digital topographic data has led to the development of analytic methods for landslide hazard estimation that couple steady state hydrological models with slope stability calculations because these methods typically neglect the transient effects of infiltration on slope stability results cannot be linked with historical or forecasted rainfall sequences estimates of the frequency of conditions likely to cause landslides are critical for quantitative risk and hazard assessments we present results to demonstrate how a transient infiltration model coupled with an infinite slope stability calculation may be used to assess shallow landslide frequency in the city of seattle washington usa a module called crf critical rainfall for estimating deterministic rainfall thresholds has been integrated in the trigrs transient rainfall infiltration and grid based slope stability model that combines a transient one dimensional analytic solution for pore pressure response to rainfall infiltration with an infinite slope stability calculation input data for the extended model include topographic slope colluvial thickness initial water table depth material properties and rainfall durations this approach is combined with a statistical treatment of rainfall using a gev general extreme value probabilistic distribution to produce maps showing the shallow landslide recurrence induced on a spatially distributed basis as a function of rainfall duration and hillslope characteristics

earthquake induced rockfall hazard zoning abstract a methodology for quantitative probabilistic hazard zonation for earthquake induced rockfalls is presented and demonstrated in the area of friuli eastern italian alps affected by the 1976 mw 6 5 earthquake four rockfall datasets have been prepared both from historical data analysis and field surveys the methodology relies on a three dimensional hazard vector whose components include the rockfall kinetic energy the fly height and the annual frequency the values of the first two components are calculated for each location along the slope using the 3d rockfall runout simulator hy stone the rockfall annual frequency is assessed by multiplying the annual onset frequency by the simulated transit frequency the annual onset frequency is calculated through a procedure that combines the extent of unstable areas calculated for 10 different seismic hazard scenarios with different annual frequencies of occurrence and the magnitude relative frequency relationship of blocks as derived from the collected field data for each annual frequency of occurrence the unstable area is calculated as a function of morphometric and earthquake characteristics a series of discriminant analysis models using the rockfall datasets and dems of different resolution 1 and 10 m identified the controlling variables and verified the model robustness in contrast with previously published relationships we show that the slope curvature plays a relevant role in the computation of the unstable area

superposed deposits of thick coal on the eastern edge of the illinois basin and their association with underlying geologic features abstract comparison of maps produced from publicly available data drillers logs electrical logs and mine maps provides a basis for inferring a deep seated influence on the distribution of superposed deposits of thick coal 1 4 m in four middle pennsylvania desmoinesian series coal beds in three mining districts of west central indiana thick sandstone 18 m is common in areas between and around the mining districts but less than 3 percent of the study area consisting of 3200 km 2 is underlain by both thick coal and thick sandstone only thick sandstone associated with the survant coal member linton formation and informally referred to by us survant sandstone exists in all of the thin coal areas after comparison with published maps by other authors it is inferred that distribution of the survant sandstone which was deposited immediately after a long period of slow deposition associated with the colchester coal member linton formation may reflect topographic expression of long term subsidence associated with differential thinning of much deeper silurian strata 580 m below although the findings of this study provide the basis for a conceptual geologic model with a hypothetical structure that is amenable to statistical testing such analysis should be undertaken only after the data are analyzed for randomness spatial autocorrelation linearity and normality

seismic and geological controls on earthquake induced landslide size abstract landslide size controls the destructive power of landslides and is related to the frequency of occurrence with larger landslides being less frequent than smaller ones for this reason the analysis of landslide size is essential for landslide hazard assessment we analyse six earthquake induced landslide inventories with earthquake magnitude ranging between 6 6 and 7 9 mw papua new guinea 1993 chichi 1999 northridge 1994 niigata chuetsu 2004 iwate miyagi nairiku 2008 wenchuan 2008 for each inventory we developed magnitude frequency curves to analyse the size distribution of landslides as a function of ground motion distance from the seismic source both fault trace and epicentre local relief and lithology for three earthquakes we observed a clear relationship between the landslide size and ground motion with larger landslides associated with higher ground motion we investigate different possible causes for such observation and propose that the main mechanical reason is that stronger shaking induces higher stresses that may overcome the strength which increases with depth triggering larger landslides we also show that landslide size decreases with distance from the fault trace whereas this trend is not clear for distance from the epicentre local relief does not seem a first order control on landslide size for the earthquake induced landslides considered here some lithologies do influence landslide size but we were unable to identify a general behaviour for different lithologies

quantifying 40 years of rockfall activity in yosemite valley with historical structure from motion photogrammetry and terrestrial laser scanning abstract rockfalls and rockslides are often dominant geomorphic processes in steep bedrock landscapes but documenting their occurrence can be challenging requiring frequent monitoring and well resolved spatial data repeat application of remote sensing methods such as terrestrial laser scanning tls and structure from motion sfm photogrammetry can detect even very small rockfalls but typically these acquisitions span only years and may not record rockfall activity representative of longer term rates of cliff erosion inventory databases can extend rockfall records but are commonly incomplete and prone to observation bias we employed tls and sfm on two adjacent cliffs el capitan and middle brother in yosemite valley integrating semi annual data collections from 2010 to 2017 with historical archival sfm models derived from oblique photographs taken in 1976 comparing the 1976 sfm models against more recent data allows for more accurate and precise rockfall detection and volume measurement over a 40 year period change detection indicates that 235 rockfalls occurred from the two cliffs more than twice as many events as are recorded in yosemite s inventory database although individual rockfall volumes reported in the inventory database vary from those measured by sfm tls reported cumulative volumes are similar to measured volumes likely because the large volume events that account for most of the cumulative volume tend to be widely observed and well documented volume frequency relationships indicate that the cliffs erode predominantly by less frequent larger volume rockfalls at rates of 0 9 to 1 7 mm yr our study demonstrates how integrated sfm and tls measurements especially utilizing sfm models derived from historical imagery allow detection and quantification of rockfalls spanning several decades complementing and improving inventory databases informing rockfall hazard assessment and providing longer term rates of cliff erosion

quantitative liquefaction induced lateral spread hazard mapping abstract to quantitatively map regional lateral spread hazard considering a complete portfolio of possible earthquakes is fundamental for a seismic risk assessment over large spatial coverage this paper presents a probabilistic model of liquefaction induced lateral spread considering seismic randomness and uncertainty of soil properties this model enables quantitative maps of lateral spread displacement at any exceedance probability in a specified time period or exceedance probability of any pre defined displacement threshold two mapping procedures are illustrated through a case study by generating hazard maps of lateral spread based on available cone penetration test data these maps highlight the hotspots susceptible to serious lateral spread displacements providing useful information on need of project specific in depth geotechnical investigation the mapping procedure is based on either geostatistical interpolation or stochastic simulation the geostatistical interpolation method has the merit to be less computationally expensive while the stochastic simulation method seems more rational as it explicitly model the uncertainty of soil parameters and their spatial structure

sediment flux from a mountain belt derived by landslide mapping in humid uplands landsliding is the dominant mass wasting process in the western southern alps of new zealand landslides are scale invariant and have a power law magnitude frequency distribution independent studies from other regions suggest that this is a general property of landsliding this observation is of critical importance to the evaluation of the impact of events of different length scales over different time intervals on landscape evolution it is particularly useful when estimating regional geomorphic rates because it constrains the frequency and overall significance of extreme events which cannot otherwise be evaluated by integrating the complete response of the system we estimate the regional denudation rate due to landsliding to be 9 4 mm yr 1 sediment discharge from the western southern alps is dominated by landslide derived material

optical properties of some tertiary coals from northeastern india their depositional environment and hydrocarbon potential abstract in northeastern india the coalfields of arunachal pradesh assam and nagaland are disposed along a linear belt of overthrusts known as the belt of schuppen where tertiary strata have been folded and dispersed into a number of thrust slices the coal bearing sediments in this belt are associated with the baragolai and tikak parbat formations of the barail group oligocene in meghalaya the tertiary sediments were deposited on a stable shelf along the periphery of the shillong plateau they are almost undisturbed and sub horizontal in attitude the coal seams are associated with the sylhet tura formations palaeocene of the jaintia group the chemical properties of these coals show characteristics of both low on volatile matter content and high on moisture and calorific value ranks the coals have a low softening temperature and a high swelling index volatile matter hydrogen and sulphur contents besides having the highest tar yield among indian coals the syncrude produced from these coals shows similarities with the identical fraction of crude oil from nahorkatiya oilfield assam the coals from the belt of schuppen and meghalaya are non banded and bright in nature microscopically their humic components are strongly decomposed with a common to frequent association of framboidal pyrite and calcite concretions the coals are vitrinite rich 52 0 80 0 with moderate amounts of liptinite macerals 5 8 16 2 the inertinite content is low 4 6 11 0 to occasionally high 30 0 fluorescing vitrinite and liptinite macerals constitute 46 5 to 83 5 by volume m m f perhydrous vitrinite liptodetrinite and resinite are the most common fluorescing macerals the rank of the coal samples r 0 max 0 57 0 74 ranges between high volatile bituminous c and b stages the assam coals are higher in rank than those of nagaland and meghalaya in northeastern india during the palaeocene and oligocene epochs peat swamps formed in situ from tropical mangrove rich angiospermous forest vegetation the palaeocene coals in meghalaya were formed in estuaries or lagoons however the coal forming phase ceased shortly due to prolonged marine transgression the oligocene coals in the belt of schuppen were formed during a regressive phase in back water lagoons or brackish water swamps on a prograding delta complex the hydrocarbon potential mg ch g c org of the coal samples from northeastern india has been theoretically deduced on the basis of their kerogen types following mukhopadhyay et al 1985 the presumed hydrogen index varies from 250 to 430 and 300 to 470 mg ch g c org respectively for coals in the belt of schuppen and meghalaya evidence indicates that in arunachal pradesh assam and nagaland oil has been generated from kerogen types ii b and ii a in the oligocene mudstone siltstone shale association of the coal measures of barail group in meghalaya no oil is known so far nevertheless the predominance of kerogen types ii a and ii b in coals indicates a good oil potential in the palaeocene sediments of the jaintia group

from landslide susceptibility to landslide frequency a territory wide study in hong kong abstract rain induced shallow landslide is the major type of landslide that happens on natural terrain in hong kong due to its high seasonal rainfall and deep weathering soil profile the geotechnical engineering office has been in a leading role to steer the risk management of natural terrain landslides in hong kong recently the territory wide rainfall based landslide susceptibility model in terms of landslide density per year has been developed to predict the number of natural terrain landslides that may occur in an anticipated rainfall event subsequently the storm based landslide density has been transformed to the annual landslide frequency to compile the territory wide landslide frequency map by incorporating the mean annual frequency of occurrence of different probable rainfall scenarios the annual rainfall frequency of a particular rainfall scenario is derived from its return period determined based on the abundant real time rainfall data at a five minute interval from 110 automatic raingauges across hong kong at an average density of 10 km2 gauge the transformation is discussed in this paper together with the evaluation of the performance of the landslide frequency map in addition the potential applications of the map in hong kong and the pitfalls of the common evaluation methods including the receiver operating characteristic curve and the success rate curve are highlighted

magnitude and frequency of rock falls and rock slides along the main transportation corridors of southwestern british columbia the two main transportation corridors of southwestern british columbia are subject to a range of rock slope movements rock falls rock slides and rock avalanches that pose significant risks to r

evaluation of anfis and lr models for seismic rockfalls susceptibility mapping a case study of firooz abad kojour iran earthquake 2004 seismic rockfall is one of the prevalent geohazards that cause huge losses in the earthquake stricken areas in the present research a model is developed to map susceptibility occurrence probability of seismic rockfalls in a regional scale using logistic regression lr and adaptive neuro fuzzy inference system anfis techniques in this research firooz abad kojour earthquake of 2004 was introduced as the benchmark and the model base the susceptible zones predicted by lr and anfis methods were compared with the database distribution map of seismic rockfalls by which the results revealed a good overlapping between the susceptible zones predicted by the anfis and the field observation of rockfalls triggered by this earthquake besides for the statistical evaluation of results obtained by lr and anfis models the verification parameters with high accuracy such as density ratio dr quality sum qs and receiver operating characteristic curve roc were used by analyzing the susceptibility maps and considering the qs index obtained by lr 21 04184 and anfis 26 75592 it could be found that the qs of anfis is higher than that of lr moreover based on the obtained value of the area under the curve auc from lr 0 972 and anfis 0 984 methods anfis provided a higher accuracy in zonation and susceptibility mapping of rockfalls triggered by firooz abad kojour earthquake of 2004 compared to the lr method

a review of assessing landslide frequency for hazard zoning purposes abstract the probability of occurrence is one of the key components of the risk equation to assess this probability in landslide risk analysis two different approaches have been traditionally used in the first one the occurrence of landslides is obtained by computing the probability of failure of a slope or the reactivation of existing landslides in the second one which is the objective of this paper the probability is obtained by means of the statistical analysis of past landslide events specifically by the assessment of the past landslide frequency in its turn the temporal frequency of landslides may be determined based on the occurrence of landslides or from the recurrence of the landslide triggering events over a regional extent hazard assessment using frequency of landslides which may be taken either individually or collectively requires complete records of landslide events which is difficult in some areas its main advantage is that it may be easily implemented for zoning frequency assessed from the recurrence of landslide triggers does not require landslide series but it is necessary to establish reliable relations between the trigger its magnitude and the occurrence of the landslides the frequency of the landslide triggers can be directly used for landslide zoning however because it does not provide information on the spatial distribution of the potential landslides it has to be combined with landslide susceptibility spatial probability analysis to perform landslide hazard zoning both the scale of work and availability of data affect the results of the landslide frequency and restrict the spatial resolution of frequency zoning as well magnitude frequency relationships are fundamental elements for the quantitative assessment of both hazard and risk

probabilistic tsunami hazard assessment at seaside oregon for near and far field seismic sources 1 the first probabilistic tsunami flooding maps have been developed the methodology called probabilistic tsunami hazard assessment ptha integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment psha application of the methodology to seaside oregon has yielded estimates of the spatial distribution of 100 and 500 year maximum tsunami amplitudes i e amplitudes with 1 and 0 2 annual probability of exceedance the 100 year tsunami is generated most frequently by far field sources in the alaska aleutian subduction zone and is characterized by maximum amplitudes that do not exceed 4 m with an inland extent of less than 500 m in contrast the 500 year tsunami is dominated by local sources in the cascadia subduction zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km the primary sources of uncertainty in these results include those associated with interevent time estimates modeling of background sea level and accounting for temporal changes in bathymetry and topography nonetheless ptha represents an important contribution to tsunami hazard assessment techniques viewed in the broader context of risk analysis ptha provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard which can then be combined with vulnerability and exposure to yield estimates of tsunami risk

a rheological model for the description of boulder impacts on granular strata this paper considers the mechanics of rock boulders impacting on granular strata the study is aimed at improving the numerical methods devoted both to describing boulder trajectories along slopes and designing preventive structures in mountain regions the problem is analysed by using a simplified approach inspired by the lumped mass method this is based on a the macro element concept b the definition of generalised stresses and displacements and c delayed plasticity theory both vertical and inclined impacts on horizontal strata and vertical impacts on inclined slopes are discussed the numerical results are obtained by using a finite difference numerical discretisation to integrate over time a coupled system of two dimensional differential equations most of the input data requested by the model are basic and geotechnically meaningful and comparison of the numerical results with the experimental data seems to be quite promising

review and update of the applications of organic petrology part 2 geological and multidisciplinary applications abstract the present paper is focused on organic petrology applied to unconventional and multidisciplinary investigations and is the second part of a two part review that describes the geological applications and uses of this branch of earth sciences therefore this paper reviews the use of organic petrology in investigations of i ore genesis when organic matter occurs associated with mineralization ii the behavior of organic matter in coal fires self heating and self combustion iii environmental and anthropogenic impacts associated with the management and industrial utilization of coal iv archeology and the nature and geographical provenance of objects of organic nature such as jet amber other artifacts and coal from archeological sites and v forensic science connected with criminal behavior or disasters this second part of the review outlines the most recent research and applications of organic petrology in those fields

observations on indian permian gondwana coals under fluorescence microscopy an overview abstract macerals like sporinite cutinite suberinite and resinite of the liptinite group have been insufficiently recorded in indian permian gondwana coals until the fluorescence microscopy came into existence with the introduction of this technique macerals like bituminite fluorinite and exsudatinite were convincingly recognized and alginite and liptodetrinite normally mistaken for mineral matter under normal reflected light in routine coal petrographic analysis were identified with certainty thus fluorescence microscopy has added certain new macerals to the tally of the liptinite group and has increased their overall proportion in indian gondwana coals in addition to the liptinite group collodetrinite desmocollinite and a certain fraction of collotelinite telocollinite macerals of the vitrinite group were found to be fluorescing with dull reddish brown to dark brown colours certain semifusinite and inertodetrinite macerals of inertinite group were also found to fluoresce with almost identical intensity and colour as that of the associated perhydrous fluorescing vitrinite contributions of degraded resinite algal matter and bitumen in the formation of perhydrous vitrinite have been established the fluorescence behaviour of inertinite appears to be related with its genesis from partial oxidation of resin bitumen impregnated cell walls

seismic performance evaluation of high cfrd slopes subjected to near fault ground motions based on generalized probability density evolution method abstract this research mainly addresses evaluating the seismic reliability and analyzing the random dynamic response of high concrete faced rockfill dam cfrd slopes suffering from the near fault earthquakes by establishing a novel method of generating the representative acceleration time histories coupled with the recently proposed generalized probability density evolution method gpdem a probability evaluation is performed after generating two groups of near fault ground motions pulse like and non pulse like earthquakes coupling a series of statistical stochastic parameters with the spectral representation random function method a 242 m high cfrd is selected as an example for finite element stochastic dynamic time series analysis and second order statistical values including mean and standard deviation and probability information of three indices the safety factor the cumulative time of safety factor 1 0 fs 1 0 and the maximum cumulative slippage of the dam slopes are determined respectively the effective non stationary near fault earthquakes will be adopted to determine the stochastic earthquake loading for the dynamic response evaluation of dam slopes the statistical and probabilistic results demonstrate that the seismic characteristics make a great difference to the seismic response of slope stability as well as the pulse properties the stochastic near fault earthquakes combined with the gpdem can evaluate seismic performance and reliability effectively from the perspective of randomness and the failure probability can be obtained directly

an approach to time probabilistic evaluation of seismically induced landslide hazard the need for effective strategies for preventing and mitigating damage caused by earthquake induced landslides has stimulated recent developments of techniques for the assessment of seismic landslide exposure at a regional scale however for a rational risk management a crucial element is represented by the time horizon of the hazardous events a new way to incorporate the time factor in seismic landslide hazard assessment is proposed here it consists of evaluating the temporal recurrence of seismically induced slope failure conditions inferred from the newmark s model first by adopting arias intensity to quantify seismic shaking well established methods of seismic hazard assessment are employed to obtain the occurrence probabilities for different levels of seismic shaking in a time interval of interest then some empirical relations based on the newmark s model are employed to evaluate the slope critical acceleration a c for which a prefixed probability exists that seismic shaking would result in landslide triggering the obtained a c values represent the minimum slope resistance required to keep the probability of seismic landslide triggering within the prefixed value therefore the space distribution of the calculated a c values can be promptly compared with the actual in situ a c values of specific slopes to estimate whether these slopes have a significant probability of failing under seismic action in the future an example of this approach applied to an area in southern italy daunia region shows that the introduction of the time factor significantly modifies the representation of the spatial hazard and allows evaluation of the relevance of seismicity as a landslide triggering agent

a probabilistic approach for landslide hazard analysis abstract we present a general framework for probabilistic landslide hazard analysis with respect to other quantitative hazard assessment approaches this probabilistic landslide hazard analysis has the advantage to provide hazard curves and maps and to be applicable to all typologies of landslides if necessary accounting for both their onset and transit probability the method quantifies for a given slope location the exceedance probability of being affected by a landslide with a specific local intensity within a reference time interval i e the hazard curve under the common assumption that landslides behave as a poisson process hazard maps are calculated reducing the hazard curve to single values by choosing a fixed probability of exceedance following standards or regulation requirements the method is based on the assessment of a landslide onset frequency a runout frequency for long runout landslides and the local definition of landslide intensity which can be expressed through different parameters according to landslide typology for long runout landslides the runout and spatially varying intensity and uncertainty are considered hazard curves and maps play a fundamental role in the design and dimensioning of mitigation structures in land planning and in the definition of risk and hazard management policies starting from the general framework we apply the methodology for rockfall hazard analysis and we test it in an area affected by the christchurch 2011 earthquake new zealand which triggered a large number of rockfalls killing five people

spectral fluorescence analysis of some liptinite macerals from panandhro lignite kutch gujarat india abstract spectrofluorimetric analyses of sporinite alginite and resinite macerals of eocene lignite from the panandhro lignite field indicate that they are distinguishable on the basis of their max and red green quotients sporinite fluorescing with bright yellow colour has an average max at 570 nm with red green quotient q 0 92 alginite botrycoccus with a bright yellow fluorescence colour has a peak average at 540 nm with q 0 71 resinite in the panandhro lignite has been categorized into five types resinite type 1 yellowish green to greenish yellow is characterized by average max at 510 nm with a q value of 0 29 in resinite type 2 bright yellow the average max occurs at 520 nm with q 0 49 resinite type 3 yellowish orange to orange shows a max average at 520 nm with a q value of 0 69 resinite type 4 has been subdivided into sub types a and b based on its mode of occurrence primary and in situ remobilized sub type 4a pale orange has a max average at 590 nm and q 0 99 whereas sub type 4b fluoresces with faint brownish orange to pale brown colours and shows an average max at 610 nm and q 1 43 the average max at 610 nm and q 2 30 with pale yellowish grey orangish brown and brown fluorescence colours characterize resinite type 5 the wavelength of maximum fluorescence intensities and red green quotients of the sporinite and alginite macerals show a very good correspondence with the rank r0 max of the panandhro lignites the spectral parameters of the maceral resinite on the other hand do not show such a relationship with rank resinite types 1 to 3 are primary in origin whereas types 4 and 5 occur both as primary and in situ remobilized resinites none of the resinite types have been observed as crack or fissure fillings the origin of the resinite types is probably related to lignite forming plant communities chiefly angiospermous vegetation as well as pre and post depositional conditions

avalanche risk mapping by simulation in this paper we present a simulation approach to mapping avalanche risk with application to settlements in iceland two simulation models are developed to calculate the probability of avalanches travelling a certain distance and of the flow being a specific width these two simulation models in combination with knowledge of the average frequency of avalanche occurrence the variability in avalanche direction and the degree of loss caused by an avalanche permit risk values to be determined for the areas of concern

magnitude frequency relation for rockfall scars using a terrestrial laser scanner abstract the analysis of the three dimensional rockfall scar geometry provides clues for the understanding of the failure mechanisms acting on cliffs of the conditioning factors and on the frequency of the events in this paper a supervised step by step methodology is presented for establishing the statistical magnitude frequency relation of rockfall scar volumes using a point cloud from terrestrial laser scanner tls data the methodology includes a procedure for identifying discontinuity surfaces calculating the areas of those which are exposed and the height of rockfall scars in the estimation of the rockfall scar volume a key issue is the consideration of the minimum spacing of the discontinuity sets to differentiate between step path surfaces and undulated ones having obtained the distributions of both the basal area and height of the scar across the slope the volume of the rockfall scars is calculated stochastically by multiplication of these two parameters by means of a monte carlo simulation both distributions of the basal area and of the rockfall scar volume are found to be power law with the exponent b ranging from 0 9 to 1 2 the relation obtained might be used as a first approach of rockfall magnitude frequency curves in large cliffs

determination of contributors to coal seam structure in sullivan county indiana abstract the structure of coal seams in sullivan county indiana is subject to local variability controlled by differential compaction underlying silurian reefs contribute to the maximum vertical variation and the underlying mississippian unconformity surface controls the distribution of the most extensive and mappable structural features the vertical magnitude orientation and lateral extent of the features should be considered during mine layout potential underlying silurian reefs can be distinguished from other contributors to coal seam structure for the purposes of petroleum exploration

trace element emissions from spontaneous combustion of gob piles in coal mines shanxi china the emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in shanxi province china have been studied more than ninety samples of solid waste from gob piles in shanxi were collected and the contents of twenty potentially hazardous trace elements be f v cr mn co ni cu zn as se mo cd sn sb hg tl pb th and u in these samples were determined trace element contents in solid waste samples showed wide ranges as compared with the upper continental crust the solid waste samples are significantly enriched in se 20x and tl 12x and are moderately enriched in f as mo sn sb hg th and u 2 5x the solid waste samples are depleted in v cr mn co ni cu and zn the solid waste samples are enriched in f v mn cr co ni cu zn sb th and u as compared with the shanxi coals most trace elements are higher in the clinker than in the unburnt solid waste except f sn and hg trace element abundances are related to the ash content and composition of the samples the content of f is negatively correlated with the ash content while pb is positively correlated with the ash the concentrations of as mn zn and cd are highly positively correlated with fe2o3 in the solid waste the as content increases with increasing sulfur content in the solid waste the trace element emissions are calculated for mass balance the emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated more than a half of f se hg and pb are released to the atmosphere during spontaneous combustion some trace element concentrations in flue gas are higher than the national emission standards thus gob piles from coal mining pose a serious environmental problem

space time landslide predictive modelling abstract landslides are nearly ubiquitous phenomena and pose severe threats to people properties and the environment in many areas investigators have for long attempted to estimate landslide hazard in an effort to determine where when or how frequently and how large or how destructive landslides are expected to be in an area this information may prove useful to design landslide mitigation strategies and to reduce landslide risk and societal and economic losses in the geomorphology literature most of the attempts at predicting the occurrence of populations of landslides by adopting statistical approaches are based on the empirical observation that landslides occur as a result of multiple interacting conditioning and triggering factors based on this observation and under the assumption that at the spatial and temporal scales of our investigation individual landslides are discrete point events in the landscape we propose a bayesian modelling framework for the prediction of the spatio temporal occurrence of landslides of the slide type caused by weather triggers we build our modelling effort on a log gaussian cox process lgcp by assuming that individual landslides in an area are the result of a point process described by an unknown intensity function the modelling framework has two stochastic components i a poisson component which models the observed random landslide count in each terrain subdivision for a given landslide intensity i e the expected number of landslides per terrain subdivision which may be transformed into a corresponding landslide susceptibility and ii a gaussian component used to account for the spatial distribution of the local environmental conditions that influence landslide occurrence and for the spatio temporal distribution of unobserved latent environmental controls on landslide occurrence we tested our prediction framework in the collazzone area umbria central italy for which a detailed multi temporal landslide inventory covering the period from before 1941 to 2014 is available together with lithological and bedding data we subdivided the 79 km2 area into 889 slope units sus in each su we computed the mean and standard deviation of 16 morphometric covariates derived from a 10 m 10 m digital elevation model for 13 lithological and bedding attitude covariates obtained from a 1 10 000 scale geological map we computed the proportion of each thematic class intersecting the given su we further counted how many of the 3 379 landslides in the multi temporal inventory affect each su and grouped them into six periods we used this complex space time information to prepare five models of increasing complexity our baseline model mod1 carries the spatial information only through the covariates mentioned above it does not include any additional information about the spatial and temporal structure of the data and it is therefore equivalent to the predominantly used landslide susceptibility model in the literature the second model mod2 is analogous but it allows for time interval specific regression constants our next two models are more complex in particular our third model mod3 also accounts for latent spatial dependencies among neighboring sus these are inferred for each of the six time intervals to explain variations in the landslide intensity and susceptibility not explained by the thematic covariates by contrast our fourth model mod4 accounts for the latent temporal dependence separately for each su disregarding neighboring influences ultimately our most complex model mod5 contextually features all these relations it contains the information carried by morphometric and thematic covariates six time interval specific regression constants and it also accounts for the latent temporal effects between consecutive slope instabilities at specific sus as well as the latent spatial effects between adjacent sus we also show that the intensity is strongly related to the aggregated landslide area per su because of this our most complex model largely fulfills the definition of landslide hazard commonly accepted in the literature at least for this study area we quantified the spatial predictive performance of each of the five models using a 10 fold cross validation procedure and the temporal predictive performance using a leave one out cross validation procedure we found that mod5 performed better than the others we then used it to test a novel strategy to classify the model results in terms of both landslide intensity and susceptibility which provides more information than traditional susceptibility zonations for land planning and management hereafter we use the term traditional simply to refer to the majority of modelling procedures in the literature we discuss the advantages and limitations of the new modelling framework and its potential application in other areas making specific and general hazard and geomorphological considerations we also give a perspective on possible developments in landslide prediction modelling and zoning we expect our novel approach to the spatio temporal prediction of landslides to enhance the currently limited ability to evaluate landslide hazard and its temporal and spatial variations we further expect it to lead to better projections of future landslides and to improve our collective understanding of the evolution of complex landscapes dominated by mass wasting processes under multiple geophysical and weather triggers