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

hydro geomorphic controls on the development and distribution of acid sulfate soils in central java indonesia abstract coastal planning policies and regulations in indonesia have not adequately considered acid sulfate soils ass as a constraint on development aquaculture is often undertaken in unsuitable areas and fish and shrimp culture systems in particular fail after a short period of production because of the impacts of ass on pond water quality and subsequently on fish and shrimp health this study describes a mapping approach based on an understanding of the hydro geomorphic controls on the formation and the distribution of ass in central java indonesia the underlying approach was to identify associations between ass development and distribution within estuarine hydro geomorphological units hgus this study utilized a multi level methodology involving multi resolution remotely sensed data and gis analysis coupled with field and laboratory based data to obtain hydro geomorphic and soil information at different mapping scales an estuary classification scheme for central java identified river tide and wave dominated estuaries as the dominant estuary types hgus were identified in each estuary type to define the relationships between landform development processes and pyrite concentration in soil layers thirty nine hgus were classified based on landforms marine and fluvial hydrology geomorphic processes land use and vegetation types field and laboratory assessment of soil properties were undertaken to identify the horizontal distribution of ass in the hgus and its vertical character in soil profiles in contrast to previous studies the results showed that estuaries located in low energy environments on the north coast have low

run out of cut slope landslides mesh free simulations this study uses an incompressible smoothed particle hydrodynamics isph model to investigate the run out and deposit morphology of granular materials flowing down cut slopes the primary aim is to study the influence of various factors on the run out and to summarise a quantitative relationship for direct use in landslide hazard management in the model the granular materials are modelled as a rigid perfectly plastic material with a coulomb yield surface the coupled continuity equation and momentum equation are solved by a semi implicit algorithm the model is first validated and its results are carefully compared with various controlled experiments regarding granular flows the model reproduces the flows and correctly predicts the deposition profiles under various conditions then the computational results are used to study the run out and mobility of landslides for granular columns collapsing onto a flat surface a normalised run out and a new scaling relationship are proposed which are supported

triggering of liquefaction flow slides in coastal soil deposits abstract liquefaction flow slides have been observed in coastal soil deposits throughout the world the causes of many of these slides have never been well understood the materials involved in and circumstances surrounding eight reported liquefaction flow slides are reviewed and compared many of these slides have occurred in very similar materials shortly following small to moderate drawdowns of the adjacent water level liquefaction susceptibility of sands may be evaluated by steady state methods recent research indicates that liquefaction of loose sands similar to those typically involved in these slides may be triggered by very small changes in stress conditions if the sand is initially in equilibrium under high shear stresses the triggering of liquefaction may lead to flow sliding if the unbalanced driving stresses exceed the steady state strength of the liquefied soil elasticity methods are used to estimate the initial stress conditions in a gentle infinite slope and the effect of unloading due to drawdown it is shown that liquefaction flow slides in coastal soil deposits may be initiated by small to moderate drawdowns consistent with those observed in actual slides

effects of nonplastic fines on static liquefaction of sands des essais triaxiaux en compression non draines ont ete effectues sur des echantillons reconstitues de sable du nevada et d ottawa avec variation systematique de la teneur en fines particules inferieures a 0 074 mm afin d evaluer l effet de la fraction fine sur le potentiel de liquefaction statique lors d un chargement monotonique les fines etaient non plastiques les resultats indiquent clairement que la presence de fines peut augmenter considerablement le potentiel de liquefaction statique des quatre sables propres etudies lorsqu on utilise la technique du montage a sec avec un entonnoir les fines semblent creer dans le sol une structure particulaire tres compressible ce qui accroit ainsi le potentiel de liquefaction alors meme que la densite augmente accroitre la teneur en fines d un sable propre peut aboutir a l augmentation du potentiel de liquefaction jusqu a un seuil maximum pour lequel les fines dominent le comportement non draine du sol a ce point la le potentiel de liquefaction tend a devenir constant vis a vis de l indice de densite on a trouve que la liquefaction statique complete pouvait intervenir a un indice de densite superieur a 60 pour des teneurs en fines elevees

influence of rice cultivation on the abundance and fractionation of fe mn zn cu and al in acid sulfate paddy soils in the pearl river delta abstract many of the areas dominated by acid sulfate as soils in southern china have been reclaimed for rice cultivation and represent an important source of agricultural production and food security for the local population in this study we examined the abundance and partitioning of fe mn zn cu and al in both rice paddy fields and uncultivated fields by using a six step sequential extraction procedure rice cultivation significantly reduced acidity levels at soil depths of 0 100 cm but acidity at depths of 100 140 cm increased significantly a substantial loss of mn in the oxide and acidified soil layer 0 100 cm compared to the underlying parent material was observed but there were few changes in the concentrations of fe and zn throughout the soil profile however both cu and al were substantially enriched in the superficial soil 0 40 cm compared to the underlying subsoil 40 140 cm in general leaching of fe mn and al was higher in the paddy fields because of intensified irrigation and flood conditions whereas accumulation of cu mainly in the form of acid soluble and crystalline iron oxide cu was higher in the paddy fields than in the uncultivated fields the most marked declines in metal concentrations occurred in the labile and acid soluble fractions as a result of rice cultivation which increased leaching of the readily mobilized labile and acid soluble fractions of heavy metals in these soils

lake deposits of moderate salinity as sensitive indicators of lake level fluctuations example from the upper rotliegend saline lake middle late permian northeast germany abstract the rotliegend saline lake periodically covered wide areas of the southern permian basin in northwest europe during the permian the sedimentology mineralogy and geochemistry of lake deposits were studied to document very high frequency lake level fluctuations and to evaluate their triggers increased precipitation and marine ingressions into the basin resulted in lake extension increased run off is documented by intercalated fluvial deposits in low salinity deposits of the lake because lake deposits reflect mainly deposition in relatively wet climate phases they are not correlatable to halite deposits in other basin areas decreased precipitation is followed by shrinkage of the lake desiccation at its margins and higher lake salinity due to concentration of the brine carbonate and anhydrite contents of lake deposits increased considerably before the areas fell dry but halite is not preserved in the study area falling lake level is also reflected by the occurrence of wave ripples reflecting decreased water depth and finally by desiccation and formation of evaporite crusts not only the mineralogical content but also the colour of lake claystones changes with varying salinity anhydrite and carbonate free red claystones were replaced by violet to green and grey anhydritic and calcareous claystone or marls with increasing salinity the amount of boron adsorbed on illite also corresponds to changes in salinity and can therefore be used as a palaeosalinity indicator rare earth element concentrations within lake deposits do not reflect variations in salinity but different palaeogeographical settings marine ingressions into the lake are neither reflected by the amount of boron adsorbed onto illite nor by rare earth element contents of the lake deposits highly saline deposits are partly characterised by intensive deformation which can be interpreted as seismites or dissolution breccias

early permian rotliegendes palaeowinds of the north sea abstract the classical desert sediments of the early permian upper rotliegendes were deposited in a post variscan basin that extends from eastern england to the russo polish border which has been referred to as the southern permian basin these sediments comprise four main depositional facies fluvial wadi aeolian sabkha and lacustrine the lacustrine facies includes important bedded halites the southern permian basin is separated from the smaller northern permian basin by the fragmented mid north sea ringkobing fyn system of highs and beyond the grampian spur lies the even smaller moray firth basin these latter basins contain rock sequences similar to those of the southern basin with the exception that bedded halite has not been recognised in the lacustrine facies the rotliegendes of the southern basin apparently conforms to deposition in a northern hemisphere tradewind desert similar to the modern southern sahara apart from regional palaeomagnetic considerations and the occurrence of sediments of a non arid nature south of the variscan highlands the strongest evidence supporting this interpretation is the pattern of palaeowind directions deduced from the orientations of dune bedding this is seen in both outcrop and core and derived from the continuous dip meter logs of many north sea wells by plotting the poles to the bedding attitudes on polar nets palaeowind directions have also been deduced from the dip meter logs of wells drilled in the northern and moray firth basins in general they indicate winds that blew in a direction opposed to those of the southern basin thus an area of high barometric pressure seems to have been located over the mid north sea high when the bedding attitudes in a well are roughly unidirectional an origin on a transverse dune is normally indicated with some wells the indicated palaeowind direction is regionally anomalous in many cases this can be rectified if the well is presumed to have drilled down through one flank of a seif dune the indicated palaeowind is thus changed by up to 90 and then commonly fits the regional pattern these early permian desert basins were smaller and closer to the equator than the modern sahara their location in the centre of a continent between the caledonian and variscan mountain ranges suggests the analogy of a more tropical equivalent of the central asian takla makan desert

an empirical statistical model for debris flow travel distance an empirical model is presented for analysis of debris flows based on field observations of landslides from clear cuts in the queen charlotte islands british columbia given an initial failure volume changes in event magnitude arising from entrainment and deposition along the path of movement are used to establish the point at which the cumulative flow volume diminishes to zero and therefore the total travel distance hillslope morphology is used to assign three types of flow behaviour unconfined confined and transition flow flow behaviour and slope angle determine the occurrence of entrainment or deposition in the model for every reach of the event path volume change in a reach is calculated from regression analysis of the queen charlotte islands field observations predictor variables are reach length width of entrainment and or deposition and slope angle together with a bend angle function and the incoming flow volume key words slope stability debris flow travel distance runout ris

dynamic analysis of the 2012 johnsons landing landslide at kootenay lake british columbia the importance of undrained flow potential the johnsons landing landslide occurred on 12 july 2012 on the shores of kootenay lake british columbia the landslide consisted of poorly sorted low plasticity debris that initially descended a

overrun length of avalanches overtopping catching dams cross comparison of small scale laboratory experiments and observations from full scale avalanches 1 results from small scale and full scale experiments on avalanche dam interactions are presented and compared these experiments were analyzed with respect to the overrun length i e the distance that the avalanche traveled beyond a catching dam the differences and similarities in the results are discussed through a cross comparison of the small scale experiments and by comparing them with observations from ryggfonn on avalanche dam interactions further we establish a simple relationship that appears to be valid for small scale experiments with granular materials as well as for full scale avalanche experiments the relationship relates the overrun length to the speed of the approaching avalanche and the effective height of the catching dam

control of soil acidification by fluvial sedimentation in an estuarine floodplain eastern australia abstract a shallow stratigraphic sequence with associated pyrite induced soil acidification was investigated along a transect from the levee to the backswamp in an estuarine floodplain of eastern australia three sedimentary layers were identified and interpreted to correspond with three depositional stages firstly a layer of humic pyrite rich silty mud was deposited under a saline mangrove inhabited intertidal environment during the present high sea level episode this pyritic layer is buried by the second sedimentary layer of grey brown mud with limited pyrite content that was deposited in a brackish lagoonal environment this material now represents much of the contemporary backswamp surface the third sedimentary layer is a sandy mud without pyrite that has been deposited by freshwater overbank floods it is concluded that fluvial sedimentation has been increasingly important in the development of the stratigraphic sequence controlling the pyrite content thickness and occurrence depth of the pyritic layer the present drainage conditions have allowed oxidation of pyrite in the soils of the backswamp and the resulting acidification has caused elevated concentrations of toxic aluminium that threaten the local environment however in the levee the pyritic layer is covered by thick non pyritic freshwater sediments and low pyritic lagoonal sediments and the soil profiles are unlikely to contribute to any acidification hazard

the angle of reach as a mobility index for small and large landslides the relations between the angle of reach fahrboschung and other indexes expressing the mobility of landslides and vertical drop horizontal reach and volume of landslide mass have been analyzed by means of simplified plots and regression equations results for 204 landslides of all sizes show that whatever the mechanism of motion all kinds of landslides experience a continuous reduction of the angle of reach with volume increase this reduction starts from the smallest sizes scattering in this relation is mostly due to mechanisms of motion and to both obstacles and topographic constraints on the path this synthesis indicates that small landslides less than 0 5 106 m3 in relative terms display excesses of travel distance similar to large landslides since most small landslides are not expected to develop any change in the mechanism of progression while moving the decrease in the reach angle with volume suggests that scale effects should be taken into account the angle of reach is found to be

rare earth element behavior in soils and salt pan sediments of a semi arid granitic terrain in the western cape south africa the rare earth element ree contents of soils and pan sediments of the darling hills granitic terrain of southwestern south africa were determined to study the behavior of ree during weathering in a semi arid mediterranean climate the p rich stype bedrock granite has a middle ree mree enrichment relative to post archean australian sedimentary rocks paas that primarily reflects the ree content of feldspar and accessory apatite initial chemical weathering of the granite results in the loss of ree particularly ce eu and the heavy ree hree the enrichment of ree in soils relative to bedrock granite corresponds to clay mineral and amorphous fe oxide content in the case of the light ree lree and precipitation of pedogenic calcite in the case of the hree quartz sand dilutes the ree content and concentration of k feldspar produces positive eu anomalies cerium is rapidly precipitated during weathering and retained in clayey upper soil horizons as insoluble ceo2 most pan sediments have a bowl shaped ree pattern that is derived from the accumulation of eroded catchment soils modified by precipitation of evaporative carbonates ree enrichment particularly lree and the large negative ce anomaly of oxidized basal pan sediment relative to the bedrock granite suggest that ree entering the pan by groundwater flow are sorbed onto amorphous fe oxides in contrast goethite rich nodules from the pan have a low ree content and show hree enrichment relative to the granite precipitation of pedogenic calcite and evaporative pan carbonates greatly increases the retention of the hree in these semi arid soils diagenetic pan dolomite has a ree pattern similar to pedogenic and evaporative calcite but with a significantly lower ree content the ree patterns indicate that although most abundant in the bedrock granite the mree are least retained by soils during weathering the lree are generally retained by clayey and amorphous fe oxide rich soils and sediments whereas hree are retained by precipitation of soil and pan carbonates d 2003 elsevier b v all rights reserved

the stratigraphic and geochemical record of playa cycles monitoring a pangaean monsoon like system triassic middle keuper s germany abstract the combination of high resolution stratigraphy with high resolution geochemistry allowed monitoring the cyclicity of a playa system in two dimensions time and space the playa cycles of the middle upper triassic steinmergel keuper located in southern germany were studied both in terms of lateral facies shift variations and long term cyclic patterns the lateral variation was expressed by investigating a time equivalent transect that spanned the kieselsandstein horizon within a 130 km distance from marginal to mid playa position whereas the long term cyclic pattern was investigated in core malschenberg where a time record of ca 5 106 years was encountered mudstone dolomite cycles with dolomites representing the wet and mudstones the dry phases reflect cyclic playa lake level changes indicating varying intensities of monsoon like circulation moisture transport from the tethys ocean into the german basin is implied by 18o depletion trends of isochronous dolomite beds from the margin to mid playa position suggesting dominantly rayleigh like circulation patterns distinct covariance of 18o 13c is used as indicator of lake level stands the k al curve with inverse covariation compared to 18o reflects fluctuating weathering conditions on the fan and the vindelician high a hierarchic cycle stacking pattern composed of metre scale to tens of metre cycles is interpreted to be a result of changing pangaean monsoon like intensities in the milankovitch frequency band spectral analysis shows that the power spectra are dominated by precession and eccentricity

presenting regional shallow landslide movement on three dimensional digital terrain abstract a storm can trigger numerous shallow landslides on hilly terrains this paper presents a distributed cell model for presenting regional shallow landslide movement on a three dimensional digital terrain the model consists of five components namely a digital terrain module a spatial rainfall distribution module an infiltration analysis module a slope stability evaluation module and a movement prediction module the locations and volumes of landslides are analyzed first through rainfall infiltration and slope stability analyses the detached material is assumed to move along the steepest path from one cell to a lower cell empirical equations that are developed based on local landslide inventories are adopted as a landslide movement cessation criterion the effect of landslide size on travel distance is considered by grouping unstable cells that are bounded at least at one side or corner the uncertainties in soil shear strength parameters and the landslide movement process are considered in determining the possible bounds of travel distance the movement analysis method is applied to a 164 5 km 2 hilly terrain in the wenchuan earthquake zone to test its performance in presenting regional shallow landslide movement the method predicts the volume of landslides reasonably well the observed and computed movement traces and deposition locations of the detached material also agree reasonably well the volume of individual landslide and travel distance may be substantially underestimated if the size effect is not considered

the influence of shallow landslides on sediment supply a flume based investigation using sandy soil abstract the impact of rainfall induced shallow landslides on hillslope sediment discharge is not well understood this paper reports experimental measurements of sediment discharge after water induced shallow landslides are triggered on sandy soil in a flume under simulated rainfall the principal aim of the research was to investigate how varying soil depth affects the location and occurrence of shallow slope failures as well as how it affects sediment yields downslope four experiments were conducted using the same sandy soil and a 30 and 10 compound slope configuration under average rainfall intensity of 50 mm h 1 for up to 390 min soil depths were set to 200 300 400 and 500 mm engineering and geotechnical properties of the soil were examined sediment discharge and runoff were collected from the flume outlet at 15 minute intervals changes in the soil slope profiles after landslides and soil physical properties resulted from soil armouring under continuous rainfall were also recorded results showed that sediment yields at the flume outlet before landslides occurred were very low and limited to the finer soil particles as would be expected for a sandy soil however subsequent variations in sediment discharge were strongly related to failure events and their proximity to the outlet sediment yield was also affected by the original soil depth the greater the depth the higher the sediment yields post failure reductions in sediment discharge were observed and attributed to post failure slope stabilization under continuing rainfall and extensive soil armouring near the flume outlet the results provide a clear linkage between landslides and sediment discharge due to hydrological processes occurring in the hillslope this knowledge is being used to develop a model to predict sediment discharges from hillslopes following shallow landslide events

runout simulation of seismic landslides using discontinuous deformation analysis dda with state dependent shear strength model the reliable numerical simulation of the landslide process contributes to the establishment of evidence based disaster mitigation measures in seismically active zones to achieve this goal a simpl

on the origin of the southern permian basin central europe abstract a detailed study of the structural and stratigraphic evolution of the southern permian basin during latest carboniferous to early jurassic times supported by quantitative subsidence analyses and forward basin modelling for 25 wells leads us to modify the conventional model for the rotliegend zechstein development of this basin the late permian early jurassic tectonic subsidence curves are typical for a permian to early triassic extensional stage that is followed by thermal subsidence however a purely extensional model is extremely problematic because active faulting during this time is minor and generally hard to document using inverse techniques to model the subsidence curves we quantitatively show that a significant component of late permian and triassic tectonic subsidence can be explained by thermal relaxation of early permian lithospheric thinning and by delayed infilling of paleo topographic depressions that developed during the early permian in this interpretation stephanian autunian wrenching resulted in thermal destabilisation of the lithosphere deep fracturing of the crust disruption and erosion of its sedimentary cover and regional uplift of the area of the future southern permian basin upon termination of wrench tectonics and associated volcanism towards the end of the autunian the southern permian basin began to subside in response to thermal contraction of the lithosphere the evolving basin was isolated from the world oceans and had subsided possibly up to some 700 m below their level at the beginning of upper rotliegend sedimentation after catastrophic flooding of this paleo topographic depression at the beginning of the zechstein changing sea level sedimentation and subsidence rates remained essentially in balance although the effects of triassic rifting overprinted parts of the southern permian basin its overall subsidence pattern persisted well into the jurassic in contrast to the remainder of the southern permian basin permian and triassic crustal extension contributed significantly to the subsidence of the polish trough

morphometric analysis of relic landslides using detailed landslide distribution maps implications for forecasting travel distance of future landslides abstract this study analyzed the morphometry of relic landslides in four mountainous areas in japan using detailed landslide maps issued by the national research institute for earth science and disaster prevention of japan the mobility of 338 relic landslides was evaluated based on the h l ratio i e the equivalent coefficient of friction the h l ratio strongly correlates with the initial slope tan r r 2 0 78 0 88 the h l ratio and tan r of recent disaster causing landslides within the past few decades were also measured in each investigated area the data of recent landslides correspond to the 95 lower prediction limit of the tan r h l regression line for relic landslides this result implies that morphometric analysis of relic landslides around an unstable mass allows for forecasting of travel distance of the unstable mass

transformation of dilative and contractive landslide debris into debris flows an example from marin county california abstract the severe rainstorm of january 3 4 and 5 1982 in the san francisco bay area california produced numerous landslides many of which transformed into damaging debris flows the process of transformation was studied in detail at one site where only part of a landslide mobilized into several episodes of debris flow the focus of our investigation was to learn whether the landslide debris dilated or contracted during the transformation from slide to flow the landslide debris consisted of sandy colluvium that was separable into three soil horizons that occupied the axis of a small topographic swale failure involved the entire thickness of colluvium however over parts of the landslide the soil a horizon failed separately from the remainder of the colluvium undisturbed samples were taken for density measurements from outside the landslide from the failure zone and overlying material from the part of the landslide that did not mobilize into debris flows and from the debris flow deposits the soil a horizon was contractive and mobilized to flows in a process analogous to liquefaction of loose granular soils during earthquakes the soil b and c horizons were dilative and underwent 2 to 5 volumetric expansion during landslide movement that permitted mobilization of debris flow episodes several criteria can be used in the field to differentiate between contractive and dilative behavior including lag time between landsliding and mobilization of flow episodic mobilization of flows and partial or complete transformation of the landslide

hydrogeochemistry and rare earth element behavior in a volcanically acidified watershed in patagonia argentina abstract the rio agrio watershed in northern patagonia argentina is naturally acidic due to discharges of volcanic h 2 so 4 hcl and hf at its headwaters near the summit of copahue volcano a suite of water samples was collected from the summit of the volcano to a point roughly 40 km downstream where the ph of the rio agrio rose above 6 0 this suite included a sample of the hyperacidic ph the concentrations of ree in the rio agrio decreased by several orders of magnitude through the study area as a result of dilution and chemical attenuation a subtle shift in the slope of shale normalized profiles of dissolved ree concentration was observed from being weakly positive near the source of the rio agrio to showing a weak middle ree enrichment trend in lake caviahue to being weakly negative in the lower reaches of the river the trend to a negative slope across the lanthanide series in the lower river is explained by selective partitioning of the heavier ree to hydrous oxides of fe and al suspended in the water column and accumulating on the riverbed most of the decrease in ree load occurred immediately downstream of the confluence with a tributary that increased the ph of the rio agrio from 4 3 to 6 1 although the mixed water was supersaturated with ree phosphate compounds precipitation of lnpo 4 is not believed to have been a dominant process because the predicted pattern of inter element fractionation from phosphate deposition is inconsistent with the observed trends instead ree attenuation most likely occurred from adsorption onto freshly precipitated hydrous aluminum oxide the behavior of ree in the rio agrio watershed is broadly similar to what has been observed in watersheds that owe their acidity to oxidation of sulfide minerals

the size distribution and mobility of landslides caused by the 2015 mw7 8 gorkha earthquake nepal abstract coseismic landslides pose immediate and prolonged hazards to mountainous communities and provide a rare opportunity to study the effect of large earthquakes on erosion and sediment budgets by mapping landslides using high resolution satellite imagery we find that the 25 april 2015 m w 7 8 gorkha earthquake and aftershock sequence produced at least 25 000 landslides throughout the steep himalayan mountains in central nepal despite early reports claiming lower than expected landslide activity our results show that the total number area and volume of landslides associated with the gorkha event are consistent with expectations when compared to prior landslide triggering earthquakes around the world the extent of landsliding mimics the extent of fault rupture along the east west trace of the main himalayan thrust and increases eastward following the progression of rupture in this event maximum modeled peak ground acceleration pga and the steepest topographic slopes of the high himalaya are not spatially coincident so it is not surprising that landslide density correlates neither with pga nor steepest slopes on their own instead we find that the highest landslide density is located at the confluence of steep slopes high mean annual precipitation and proximity to the deepest part of the fault rupture from which 0 5 2 hz seismic energy originated we suggest that landslide density was determined by a combination of earthquake source characteristics slope distributions and the influence of precipitation on rock strength via weathering and changes in vegetation cover determining the relative contribution of each factor will require further modeling and better constrained seismic parameters both of which are likely to be developed in the coming few years as post event studies evolve landslide mobility in terms of the ratio of runout distance to fall height is comparable to small volume landslides in other settings and landslide volume runout scaling is consistent with compilations of data on larger slope failures in general the size ratios of landslide source area to full landslide area are smaller than global averages and hillslope length seems to largely control runout distance which we propose reflects a topographic control on landslide mobility in this setting we find that landslide size dictates runout distance and that more than half of the landslide debris was deposited in direct connection with stream channels connectivity which is defined as the spatial proximity of landslides to fluvial channels is greatest for larger landslides in the high relief part of the high himalaya although these failures are less abundant than those at lower elevations they may have a disproportionate impact on sediment dynamics and cascading hazards such as landslide reactivation by monsoon rainfall and landslide dams that lead to outburst floods the overall high fluvial connectivity of coseismic landsliding in the gorkha event suggests coupling between the earthquake cycle and sediment geochemical budgets of fluvial systems in the himalaya

cyclicity of triassic to lower jurassic continental red beds of the argana valley morocco implications for palaeoclimate and basin evolution abstract cyclical playa deposits form a prominent part of the continental clastic succession of the argana valley western high atlas of morocco the red beds formed in triassic to lower jurassic times during rifting of the north american and african plates detailed stratigraphic work revealed asymmetrical metre scale cycles in mudstone dominated successions that constitute the intermediate and upper portion of the basin fill sedimentary cycles commonly comprise ephemeral lake shales at the base playa mudflat mudstones in the intermediate part and both fluvial and aeolian sandstones at the top cycles of the aglegal member t4 are mainly characterized by analcime rich playa mudflat deposits displaying features indicative of palaeo vertisols cycles of the sidi mansour t7 and hasseine t8 members are represented by ephemeral lake or dry playa mudflat deposits grading into saline mudflat mudstones that are overlain by sheet flow and minor aeolian sandstones sedimentary cycles of the imerhrane member t9 comprise sheet delta sandstones at the base overlain by ephemeral lake and dry playa mudflat mudstones upper cycle portions consist of aeolian dune and sand sheet sandstones cyclicity is attributed to palaeoclimatic and associated palaeohydrological fluctuations probably within the milankovitch frequency band sedimentary facies of each cycle provide evidence for a gradual climatic drying with time the asymmetrical drying upward cycles possibly record the precession cycle since they are modulated by symmetrical i e oscillating drying wetting cycles of a lower frequency indicative of eccentricity a long term change in palaeoclimate ranging from semi arid conditions with seasonal precipitation t4 towards an arid non seasonal climate t8 is preserved within the cyclical units spanning a time interval of several million years individual cycles can be traced laterally for tens of kilometres correlative sections are almost identical in thickness suggesting a phase of tectonic quiescence during their deposition sediment accumulation was not restricted to small scale grabens but took place continuously throughout the exposed area of the argana valley implying that accommodation space has not been controlled by syndepositional tectonism

instrumented laboratory flowslides flowslides have been induced in small instrumented coking coal stockpiles by slowly raising the water table these strongly resembled field cases showing sudden collapse rapid fluid like motion and very flat final slopes failure initiated under essentially static drained conditions and with a mobilized secant effective strength parameter d much less than the steady state value highspeed measurements showed that excess pore pressures were generated during rather than before movement and liquefaction was therefore a result of shear failure rather than the cause des glissements par liquefaction furent provogues dans de petites reserves de charbon cokeflant a instrumentation par elevations lentes de la nappe aquifere ils ressemblaient beaucoup a des cas sur chantier avec affaissement abrupt un mouvement rapide quasi fluide et des pentes finales tres plates la rupture commenca dans des conditions drainees essentiellement statiques et avec un parametre o de resistance effective secante mobilisee

the liquefaction of sands a collapse surface approach recent large scale slides occurring during the hydraulic placement of an artificial island berm in the beaufort sea resulted from the liquefaction of the berm sand subsequent laboratory tests and

formation mechanism analysis of irrigation induced retrogressive loess landslides abstract the loess plateau covers about 6 6 of the total land area of china landslides are serious concerns in loess plateau of china and the south jingyang tableland on the loess plateau of china has received significant attention because of frequent occurrence of gradual retrogressive loess landslides grll there however the characteristics and mechanism of grll are largely unknown in this study three typical landslide groups namely miaodian zaitou landslide group jiangliu landslide group and dabuzi landslide group are chosen as examples to analyze the characteristics of grll by performing a field survey and undrained triaxial shear tests loess fissures are found to play a key role in controlling the evolution of landslides on the one hand the mechanical properties of loess surrounding fissures rapidly weaken due to water infiltration into loess fissures on the other hand the self weight of the overlying loess increases since water infiltrates into fissures the undrained triaxial shear tests results indicate that loess specimen shows either strain hardening or strain softening behavior depending on its initial moisture content furthermore reduction in the shear strength of loess samples is observed as moisture content increases three factors associated with the characteristics and mechanism of grll group including strata lithology slope shape irrigation and rainfall are discussed finally the formation mechanism and evolution of grll are summarized into three stages namely a creep tensional stage a localized liquefaction stage and a sliding stage this study provides important insights on gradual retrogressive characteristics of loess landslides and facilitates appropriate safeguards to reduce the risk of such landslide hazards

late permian non marine marine transitional profiles in the central southern permian basin northern germany the transition from rotliegend to zechstein within the southern permian basin is one from continental desert to a marine environment during the upper rotliegend ii a huge playa lake existed there this lake was temporarily influenced by precursors of the zechstein transgression therefore the mega playa evolved into a sabkha system one of these early marine ingressions is known from an outcrop in schleswig holstein laminated silt and claystones deposited within a standing water body are intercalated in siltstones of a salt flat environment the lake sediments are characterised by high frequency cyclicity shown by the sedimentary record and also by palaeontological data the section contains fresh water as well as brackish marine and marine fauna climatically forced cycles interact with marine incursions after the zechstein transgression had flooded the basin completely sedimentation was controlled by sea level fluctuations two sections in the southern north sea and in schleswig holstein are presented in this paper cyclicities with different frequencies controlled the sedimentation of the kupferschiefer t1 and the werra carbonate ca1 sediments of the north sea sequence were deposited within a shallow bay at the margin of an elevation therefore the high frequency cyclicity became obvious within the sedimentary patterns and in the faunal content

prehistoric earthquake deformations near masada dead sea graben earthquake inducedfluidizations and suspensions of lake sediments associated with syndepositionalfaults formapaleoseismicrecordinthedeadseagraben theassociation offluidized beds with surface faulting supports the recognition of mixed layers as reliable earthquake indicators and provides a tool for the study of very long term 70 kar seismicity along the dead sea transform the faults compose a fault zone that offsets laminated sediments of the late pleistocene lake lisan they exhibit displacements of as much as 2 m layers of massive mixtures of laminated fragments are interpreted as disturbed beds each formed by an earthquake the undisturbed laminated layers between these mixed layers represent the interseismic interval a typical vertical slip of about 0 5 m per event is separated by several hundred years of quiescence the fault zone lies within the dead sea graben 2 km east of masada where archaeology and historical accounts indicate repeated strong earthquake damage the distribution of strikes in the fault zone resembles that of the faults exposed in and around the graben including the seismogenic ones the excellent exposures over hundreds of metres allow an unprecedented temporal and spatial resolution of slip events on faults

permo carboniferous climate early pennsylvanian to late permian climate development of central europe in a regional and global context a well justified stratigraphical correlation of continental successions and new palaeogeographic reconstruction of pangaea reveal new insights into the northern pangaean climate development influenced by palaeogeography palaeotopography glacio eustatic sealevel changes and ocean currents the overall permo carboniferous aridization trend was interrupted by five wet phases these are linked to the gondwana icecap the aridization and weakening of wet phases over time were not only caused by the drift of northern pangaea to the arid climatic belt but also by the successive closure of the rheic ocean which caused the expansion of arid semi arid environments in the lower middle permian the end of the gondwana glaciation rearranged ocean circulation leading to a cold coast parallel ocean current west of northern pangaea blocking moisture coming with westerly winds the maximum of aridity was reached during the roadian wordian the trans pangaean mountain belt was non existent its single diachronous parts never exceeded an average elevation of 2000 m the maximum elevation shifted during time from east to west the hercynian orogen never acted as an orographic east west barrier and the inter tropical convergence zone was widely displaced causing four seasons dry summer winter wet spring autumn at the equator and a strong monsoon system the climate history of the european realm during the late carboniferous pennsylvanian and permian is stored in many solitary basins fig 1 within the hercynian orogen and the foreland basin the story of westphalian climate is well known because of the numerous investigations of the coal bearing variscan foredeep the younger westphalian is characterized by a slight aridization abbink van kronijnenburgvan cittert 2003 oplustil 2004 which was accompanied by an increase of seasonality nevertheless the environment was strongly influenced by the ocean and epi continental seas with multiple transgression events the last extensive marine ingression was the aegir mansfield band westphalian b c the post westphalian climate development is more differentiated and

marine ingressions into the middle late permian saline lake of the southern permian basin rotliegend northern germany possibly linked to sea level highstands in the arctic rift system abstract a huge saline lake existed in the southern permian basin spb of northwest europe during late wordian to early wuchiapingian more than 2500 m thick continental siliciclastics and evaporites of the upper rotliegend ii were deposited before the marine zechstein transgression flooded the basin marine deposition took place in the arctic rift system between east greenland and the fennoscandian shield at that time interval sediments of the foldvik creek group reflect relative sea level fluctuations short termed pre zechstein ingressions from the boreal realm into the spb are known by the marine lamellibranch liebea reichei however sedimentological analysis of different saline lake horizons show that the marine influenced saline lake horizon does not differ lithologically from other saline lake claystone layers in the rotliegend succession the 87 sr 86 sr ratios of anhydrite 0 7089 0 7100 reflect deposition in a continental setting in contrast to this s isotopic values more than 11 7 cdt reflect marine pre zechstein ingressions into the spb in the middle niendorf and munster members s isotopic values of anhydrite can be used as an indicator for marine influence in the spb the pre zechstein ingressions superimpose the climatic triggered lake level fluctuations of the rotliegend saline lake two marine ingressions can be integrated into a set of regularly recurring abnormities in the depositional evolution these important evolutionary steps the saline lake formation the garlstorf ingression the p ameland and bahnsen lake level highstands the niendorf ingression and the zechstein transgression show a periodicity of more or less 1 ma one million year cyclicity is also known from deposits of the arctic rift system in east greenland wegener halvo and ravnefjeld formations a correlation of the upper rotliegend ii deposits with the succession of east greenland is proposed based on the assumption that the marine ingressions as well as the exceptionally intensive saline lake expansions could be linked to sea level highstands in the arctic rift system the result is the first correlation of upper rotliegend ii deposits with marine strata

travel distance angle for rapid landslides in constructed and natural soil slopes rapid landslides in constructed and natural soil slopes have the potential to cause loss of life destruction of property and damage to the natural environment because the velocity of the slide

rare earth element fractionation during the precipitation and crystallisation of hydrous ferric oxides from anoxic lake water abstract an enrichment of light rare earth elements lree is characteristic for most of the acidic fe and so 4 rich pit lakes and groundwaters in the lignite mining area of lower lusatia germany one of these acidic lakes the pit lake rl 1223 has a strong thermal and chemical stratification the upper water layer 0 9 m shows ph values of about 3 during all seasons the monimolimnion 10 17 m of the lake is anoxic and has ph values of about 7 the rare earth element ree patterns of the upper lake water show enriched lree la n yb n 1 6 whereas the opposite patterns depletion of lree la n yb n 0 4 are found in the anoxic water of the monimolimnion experiments were conducted to observe the behaviour of ree during fe oxidation in water from the monimolimnion depth 14 m the sampled monimolimnion water was placed in plastic bottles and the changing water chemistry was observed for 40 weeks after sampling due to the initial anoxic conditions almost all fe precipitated in the investigated water and the ph value decreased from about 7 to 3 during the oxidation the fe precipitates are identified as ferrihydrite which is transformed into goethite within the oxidation process stable ph conditions ph 3 0 were reached after about 10 weeks of oxidation the original ree patterns of the investigated water are generally reflected in the fe precipitates collected at the beginning of the experiment as well as after up to 40 weeks of oxidation however in the corresponding water lree were temporally enriched with a maximum la n yb n ratio of 1 0 and a maximum la n sm n ratio of 2 3 after 6 weeks of oxidation time ph 3 8 4 9 although complex geochemical changes took place between the start and the end of the experiment ree patterns observed at these points in time are nearly identical these differences of the ree pattern can be explained by the sampling procedure the experimental findings can be transmitted to the mining dump aquifers of the study area where geochemical conditions comparable to the experimental oxidation time from 3 to 6 weeks are found and hydrous ferric oxides are precipitating groundwater passing through the mining dumps can preferentially desorb lree from the fe precipitates and display the typical lree enrichment and carry it to the epilimnion of the acidic pit lakes in lower lusatia

a model for the runout analysis of rapid flow slides debris flows and avalanches runout analyses are used for risk assessment and design of remedial measures against rapid landslides such as debris flows debris avalanches rockslide avalanches large scale liquefaction failure

a sliding consolidation model for flow slides a model is proposed for the behaviour of flow slides in loose cohesionless materials in which the debris spreads out as a uniform sheet excess pore fluid pressures are assumed to be generated for example by undrained loading arising from the collapse of metastable structure in the source area of the flow slide under the influence of these the leading element of the debris moves downslope by basal sliding consolidating as it does so by single upward drainage as a result the pore pressure at the base of the element eventually decays to a value that brings the element to rest hence defining the run out of the flow slide the model is applicable in principle to subaqueous and subaerial flow slides and to pore fluids consisting of water gas or both of these the predictions of the model are tested against the observed behaviour and measured properties of the 1966 flow slide at aberfan south wales the results show that a sliding consolidation model provides a possible mechanism for that event

momentum transfer and friction in the debris of rock avalanches when a mass of loose dry purely frictional material slides down an incline after release at a given velocity the runout the distance the centre of gravity of the displaced mass moves from its initial position depends on momentum transfer within the mass this can be estimated from the profile of the debris accumulation which also allows more accurate calculation of apparent angles of sliding friction in rockfall avalanches the apparent extreme mobility of the elm and frank slides typical rockfall avalanches is explained by momentum transfer in a loose dry purely frictional material with an angle of friction of 30 key words mass wasting momentum transfer landslide accumulation rock avalanche runout distance

acid sulphate soil landscape relationships in an undrained tide dominated estuarine floodplain eastern australia abstract shallow stratigraphic sequences associated with the genesis of acid sulphate soils were examined in a tide dominated estuarine floodplain eastern australia the results show that the accumulation of pyrite is more significant in the site compared to the results from the previous studies in a wave dominated and a fluvial dominated estuarine plain this is in agreement with the suggestion of pons and van breemen 1982 that strong tidal action favours the enrichment of pyrite in the sediments pyritic sediments are covered by up to 1 5 metres of flood overbank sediments in the site alternating flood dominated regimes fdr and drought dominated regimes ddr are responsible for intensified overbank sedimentation during transitional periods from ddr to fdr channel bed aggradation and increasing flood frequency largely accelerate overbank deposition the overlying overbank sediments have overburdened and compacted the low bulk density pyritic sediments and resulted in insignificant increase in surface elevations this enables the accretion of overbank sediments to a considerable thickness pyrite induced acidification has occurred in this undrained estuarine floodplain rainfall analysis suggests that this process was initiated by lowering of the watertable down to the pyritic layers during prolonged drought episodes in the past re pyritization of oxidation products appears limited during high rainfall periods following these prolonged drought episodes the acidified pyritic layer may act as a storage sink of acid sulphate materials which can be transferred upwards by capillary action and acidify the non pyritic topsoils

oxygenation of acid sulfate soils stimulates co2 emission roles of acidic dissolution and hydroxyl radical oxidation abstract emission of co2 from acid sulfate soil regions has received great attention in recent years production of co2 due to microbial respiration has been documented by previous studies but the abiotic mechanisms are poorly understood in this study co2 production was measured from oxygenation of 60 acid sulfate soil samples that were collected from a typical acid sulfate soil region the soil samples were characterized by low ph 3 3 5 8 and high sulfate content 0 51 5 03 mg g the cumulative concentrations of co2 were 0 76 54 54 mol per g dry soil upon oxygenation for 24 h when 0 1 hgcl2 was added into soil suspension to kill microbes the yield of co2 decreased by 8 7 41 1 which suggests that both microbial respiration and abiotic pathways contributed to co2 production and abiotic pathway played a major role both acidic dissolution and hydroxyl radical oh oxidation were identified to be the abiotic mechanisms for co2 production for acidic dissolution co2 was produced from the decomposition of carbonate by h generated production of co2 from acidic dissolution was dependent on the content of carbonate and the generation of h a combination of fe speciation sequential extraction and kinetic model shows that h was mainly generated from the oxidation of both fe2 and pyrite by o2 for oh oxidation co2 was produced from the oxidation of organic carbon by oh produced and its relative importance for co2 production was estimated to be 14 6 27 6 oh was mainly produced from exchangeable fe ii oxidation in sulfuric horizon but from pyrite oxidation in potential acid sulfate soils this study presents the overlooked abiotic mechanisms acidic dissolution and oh oxidation for co2 emission in acid sulfate soils when perturbed by o2 our findings implicate that contribution of microbial respiration for co2 production is not as large as previously thought to be in acid sulfate soils and instead abiotic mechanisms contribute largely particularly for oxygenation of potential acid sulfate soils

quantifying and modeling post failure sediment yields from laboratory scale soil erosion and shallow landslide experiments with silty loess rainfall events on steep hillslopes can cause both soil erosion and shallow landslides these processes interact with each other and need to be studied in an integrated way to understand hillslope sediment yields the main aim of this research is to study post failure sediment yield following landslides that alter local slope gradients a laboratory flume under a rainfall simulator was used to quantify erosion and shallow landslides in fine grained silty loess soils the flume was divided into an upper and a lower section the slopes of which could be altered a total of 12 experiments were conducted on slopes ranging from 35 to 47 in the upper and 5 to 10 in the lower flume sections shallow landslides were triggered in four of the 12 experiments sediment and runoff were collected from the flume outlet every minute during landslides and every 10 min before and after landslides changes in the soil slope after landslides occurred were recorded results showed that peak sediment yields were related to landslide occurrence and proximity to the outlet post failure reduction in sediment yields was related to the evolution of the hillslope after slope failures a simple rule based soil redistribution model of runout distance was validated using the experimental results the water erosion prediction project wepp model was used to simulate runoff and soil erosion during pre and post failure rainfall events predicted runoff rates and sediment yields using wepp were in good agreement with those measured in both pre and post failure events indicating that the model can be used successfully as part of an integrated approach to modeling sediment yields in landslide prone landscapes

global time scale and regional stratigraphic reference scales of central and west europe east europe tethys south china and north america as used in the devonian carboniferous permian correlation chart 2003 dcp 2003 the boundaries of the devonian carboniferous and permian stages of the global stratigraphic reference scale abbreviated to global stratigraphic scale gss are described in relation to the biostratigraphic and or lithostratigraphic units of the regional stratigraphic reference scales abbreviated to regional stratigraphic scales rss of central and west europe east europe tethys south china eastern tethys and north america in their type regions the boundaries of gss units rarely coincide with those of homonymous rss units moreover the definitions of some rss units have changed several times over the last decades and subsequent misunderstanding of the stratigraphical significance of these changes has often introduced errors into proposed global correlation charts the stratigraphic framework proposed in our global devonian carboniferous permian correlation chart 2003 dcp 2003 devonian carboniferous permian correlation chart 2003 menning m schneider j w alekseev a s amon e o becker g von bitter p h boardman d r bogoslovskaya m braun a brocke r chernykh v chuvashov b i clayton g dusar m davydov v i dybova jachowicz s forke h c gibling m gilmour e h goretzki j grunt t a hance l heckel p h izokh n g jansen u jin y g jones p kading k ch kerp h kiersnowski h klets a klug ch korn d kossovaya o kotlyar g v kozur h w laveine j p martens th nemyrovska t l nigmadganov a l paech h j peryt t m rohn r roscher m rubidge b schiappa t a schindler e skompski s ueno k utting j vdovenko m v villa e voigt s wahlman g p wardlaw b r warrington g weddige k werneburg r weyer d wilde v winkler prins c f work d m 2004 abschlusskolloquium dfg schwerpunktprogramm 1054 evolution des systems erde wahrend des jungeren palaozoikums im spiegel der sedimentgeochemie abstracts univ erlangen germany 2004 p 43 herein abbreviated to dcp 2003 and cited as dcp 2003 in references is an attempt to reduce these errors the dcp 2003 is the stratigraphic base for project 1054 of the deutsche forschungsgemeinschaft dfg the evolution of the late palaeozoic in the light of sedimentary geochemistry this composite time scale has been carefully balanced as far as data allows to remove unnecessary artificial compression and expansion of time intervals biozonations and depositional events the ages selected in dcp 2003 are markedly different to those in the geologic time scale 1989 gts 1989 harland w b armstrong r l cox a v craig l e smith a g smith d g 1990 a geologic time scale 1989 cambridge univ press cambridge harland w b armstrong r l cox a v craig l e smith a g smith d g 1990 a geologic time scale 1989 cambridge univ press cambridge pp 1 263 and in gradstein and ogg gradstein f m ogg j 1996 a phanerozoic time scale episodes 19 1 2 3 4 insert whereas they are closer to those of the geologic time scale 2004 gts 2004 gradstein f m ogg j g smith a g 2004 a geologic time scale 2004 cambridge univ press cambridge pp 1 589 mostly the ages are rounded to the nearest 0 5 ma in order to avoid estimates of questionable accuracy whereas ages of 0 1 ma in the gts 2004 and their error bars of 0 4 ma to 2 8 ma for the devonian to permian stage boundaries suggest an improved accuracy in contrast in the dcp 2003 questionable ages and positions of stratigraphic boundaries are marked by arrows c 2006 elsevier b v all rights reserved

sandstone composition and provenance of the rotliegend of the ne german basin abstract the ne german basin contains an approximately 2 5 km thick rotliegend sedimentary section subdivided into 4 formations these were deposited following the cessation of the late carboniferous early permian volcanic episode and a ca 20 ma period of erosion and non deposition initial deposition was confined to two areas but with increasing thermal subsidence the basin extended to the south petrographic 190 sandstones and geochemical 48 sandstones and mudstones analyses suggested that the sands are quartz rich and are derived largely from cratonic or recycled sources volcanic and sedimentary rock fragments form most of the labile grains the succession was deposited in a relatively stable tectonic environment with sediment input derived largely from the lower and upper palaeozoic strata of the variscan hinterland and the upper carboniferous and lower permian volcanics volcanic input increases with younger stratigraphic units this is interpreted as resulting from the unroofing of a more basic source

liquefaction flowslides in rocky mountain coal mine waste dumps over the past 25 years there have been a large number of long runout flowslides from rocky mountain coal mine waste dumps the waste dumps are constructed as end dumped fills with an angle of repos

permian climate development in the northern peri tethys area the lodeve basin french massif central compared in a european and global context abstract the lodeve basin which contains an exceptional long and nearly uninterrupted profile of early to late permian continental red beds is well correlated to the other european permocarboniferous basins together they cover the time span from the late pennsylvanian to the permian triassic boundary although these basins were placed within the equatorial belt for the whole permian several climatic changes are recorded in the sediments terrestrial sedimentation is governed by the interaction of climate and tectonics as well as by volcanism to a variable degree therefore small scale climatic variations of the milankovitch band are hardly discernable and if so they could not be correlated between different basins indeed larger scale climatic shifts could be identified it is shown that the shift from the carboniferous icehouse to the mesozoic warmhouse was a multi stage process this global warming resulted in a general aridisation of northern pangea indicated by outspreading playa and sabkha red beds aeolianites and evaporites several short phases of increased humidity interrupted this trend indicated by wet red beds lake sediments and coal deposits in central and southern europe these wet periods are traceable within the late stephanian lower rotliegend gzhelian asselian topmost lower rotliegend asselian sakmarian upper rotliegend i late artinskian early kungurian and upper rotliegend ii zechstein wuchiapingian the aridisation of the northern pangea which accelerated near the sakmarian artinskian transition is attributed to a reorganisation of the major ocean currents cold water currents along the western flank of the pangea indicated by the permian chert event blocks moisture transport from west onto the continent during roadian and wordian the onset of an additional cold water current along the cimmerian continents blocks moisture transport from the east both phenomena together are responsible for the maximum of aridity at the early to middle permian transition additionally the equatorial climate has been affected by an increasing seasonality within the late pennsylvanian and permian caused by the wide shifting of the zone of inter tropical convergence itc over the equator based on a new reconstruction of the pangean assembly in this paper climatic changes in the permian are interpreted and causes of the arid humid arid shifts are examined phases of higher humidity are often related to events of global impact like the waxing and waning of the gondwanan glaciation obtained in the south african karoo basin dwyka group but also regional events had strong climatic influence the zechstein transgression in the northern and southern permian basin as well as the bellerophon transgression of the southern alps caused the wet phase in the wuchiapingian

influence of topography and volume on mobility of loess slides within different slip surfaces mobility of loess slides has been evaluated using an empirical approach based on a detailed field investigation and remote sensing image interpretation for all the loess slides the affected area increases with increasing loess slides volume from the statistical analysis it is seen that the travel distance has an increasing trend while the coefficient of friction has a decreasing trend with the increase in landslide volume landslide volume determine its travel distance and coefficient of friction that can be shown with a regression equation having simple power law form which indicates that the mobility of loess slides increases with increasing volumes by analogy the greater the energy of the sliding loess mass the stronger is the mobility of loess slide a plot of the travel distance of loess slide versus fall height shows a significant positive power law correlation indicating the increase in mobility of loess slide with fall height the negative power law correlation observed between the travel distance and slope inclination implies that the mobility decreases with the increase of slope inclination three datasets of loess slides characterized by different slip surfaces were distinguished the red clay contact landslides have the strong mobility than landslides in loess and bedrock contact

influence of placement method on the in situ density of hydraulic sand fills the range of densities achievable by hydraulic placement of sand straddles the boundary between values giving acceptable potential performance and those giving unacceptable potential performance this has led to concerns over the safety of structures using hydraulic fills such as the artificial drilling islands in the canadian beaufort sea liquefaction failures of hydraulically placed sand have occurred at four or more of these islands until recently the factors affecting in situ density were little understood data obtained from several artificial islands are presented and these are used to demonstrate the overwhelming influence of method of placement on in situ density the possible reasons for this influence and the implications for design are discussed recommendations are made for research that together with conclusions drawn in the paper should allow hydraulic fills to be used with more confidence in the future key words sand hydraulic fill liquefaction cone penetration test

runout analysis and mobility observations for large open pit slope failures objectively forecasting the runout of a potential open pit slope failure in addition to identifying the failure itself is a critical component of a mine s risk management plan recent losses arising from large open pit slope failures demonstrate shortcomings in current practice a dataset of 105 pit slope failures was compiled to compare open pit runout trends against established empirical runout relationships for natural landslides fahrboschung angle versus volume and fahrboschung angle versus slope angle relationships provide reasonable runout estimates open pit slopes have the advantage of removing the influence of morphological features vegetation and liquefiable substrates while controlling the travel path angle and roughness in such a controlled environment landslide mobility has a strong sensitivity to slope angle material properties and fall height and is only modestly sensitive to volume a grouping of highly mobile open pit slope cases involving weathered saturated collapsible rock

case study oso washington landslide of march 22 2014 material properties and failure mechanism abstractthis paper describes investigation testing analysis and slope history used to determine the two phase failure mechanism involved in the 2014 landslide near oso washington the first pha

acid sulphate soil landscape relationships in the pearl river delta southern china abstract relationships between the development of acid sulphate soil and landscape characteristics were examined in a fluvial dominated estuarine deltaic plain of the south china coast it was found that the accumulation of pyrite potential acid sulphate material has been limited generally by rapid sedimentation rates and insufficient supply of sulphate ion the occurrence of the pyritic sediments is however closely associated with a particular depositional pattern i e surrounding island deposition the acid sulphate soils in the area frequently occur within narrow zones surrounding present day s rocky hills previously bedrock islands this provides a guide for predicting the occurrence of potential acid sulphate soils in the area apart from the naturally large input of fluvial sediment human activities have also accelerated the delta progradation and limited the vertical accretion of the deltaic surface these effects have had significant impacts on the thickness and occurrence depth of the pyritic layer with a history of more than 1000 years of land reclamation the intensive cultivation in the area has turned most of the potential acid sulphate soils into actual acid sulphate soils however the soil properties vary markedly with landuse types the case of the pearl river delta is generally in agreement with pons and van breemen s 1982 conclusion in that the accumulation of pyrite is inversely related to the rate of sedimentation our results show that the existence of bedrock islands in the estuary basin provided zones of slow sedimentation and therefore enhanced pyrite accumulation on the other hand human intervention over the past 2000 years has acted to reduce pyrite accumulation both through landward catchment clearing that increased sediment discharge to the estuary and through empolderment and associated land management practices

distribution and characteristics of landslide in loess plateau a case study in shaanxi province abstract every year about one third of the geohazards in china occur in the loess plateau causing human loss damaging gas and oil pipelines destroying highways railways and degrading farmland field investigation and monitoring in situ tests and laboratory experiments were performed to improve our understanding of the factors effecting the distribution characteristics and causes of loess landslides first we find that 79 of the landslides are shallower than10m 85 have a volume of less than 100 000 m3 second landslides on the loess plateau occur primarily on concave slope profiles that have slope angles of 20 35 and that face south east third the equivalent coefficient of friction of loess landslides is very low resulting in long run out with a low angle sliding surface loess landslides generally transform into mud flows resulting in an increase in volume in transit and forming a geohazard chain antecedent rainfall plays an important role in triggering loess landslides finally clusters of landslides in the loess plateau occur because the loess easily disintegrates under high pressure due to its loose and highly porous structure there is a sharp decrease in cohesive strength with increase in deformation and water content and thus landslides tend to undergo static liquefaction during sliding

surface and subsurface sedimentary structures produced by salt crusts the growth and subsequent dissolution of salts on or within sediment may alter sedimentary structures and textures to such an extent that it is difficult to identify the depositional origin of that sediment and as a result the sediment may be misinterpreted to help to overcome such problems with investigating ancient successions results are presented from a comprehensive study of the morphology and fabrics of three large areas of modern salt flats in se arabia the sabkhat matti inland region and the at taf coastal region both in the emirate of abu dhabi and the umm as samim region in oman these salt flats are affected by tidal marine alluvial and aeolian depositional processes and include both clastic and carbonate dominated surficial sediments the efflorescent and precipitated salt crusts in these areas can be grouped into two main types thick crusts with high relief 10 cm and a polygonal or blocky morphology or thin crusts with low relief 10 cm and a polygonal or blister like appearance the thin crusts may assume the surface morphology of underlying features such as ripples or biogenic mats a variety of small scale textures were observed pustular growths hair like spikes and irregular wrinkles evolution of these crusts over time results in a variety of distinctive sedimentary fabrics produced by salt growth sediment deformation salt solution sediment collapse sediment aggradation and compound mixtures of these processes salt crust processes produce features that may be confused with aeolian adhesion structures an example from the lower triassic ormskirk sandstone formation of the irish sea basin demonstrates how this knowledge of modern environments improves the interpretation of the rock record a distinctive wavy laminated facies in this formation had previously been interpreted as the product of fluvial sheetfloods modified by soft sediment deformation and bioturbation close inspection of laminations seen in core reveals many of the same sedimentary fabrics seen in se arabia associated with salt crusts this facies is the product of salt growth on aeolian sediment and is not of fluvial origin

soft sediment deformation structures interpreted as seismites in lacustrine sediments of the prebetic zone se spain and their potential use as indicators of earthquake magnitudes during the late miocene lacustrine formations of late miocene age in the prebetic area se spain show several types of deformational structures that are interpreted as seismites they are present in both marginal and deep lacustrine facies seismites formed in marginal lake environments comprise sand dikes pillows and intruded and fractured gravels in deep lacustrine facies the seismites are represented by pseudonodules mushroom like silts protruding into laminites mixed layers disturbed varved lamination and loop bedding the measured orientations of these structures are consistent with the orientations of the main faults limiting the basins showing that their origin is clearly related to the tectonic stress field that prevailed in the region during the late miocene the magnitudes of the earthquakes that deformed the sediments have been estimated after published data from both ancient and recent lake deposits accumulated in tectonic active regions elsewhere a rank of earthquake magnitudes with two end members i e the lowest magnitudes recorded by loop bedding in laminites and the highest magnitudes represented by intruded and fractured gravels is proposed

landslide risk assessment prediction of travel distance the geotechnical engineering office of hong kong database of landslides for the period 1984 1993 containing over 3000 landslide records and data for major landslides before this period were made

liquefaction and flow failure during earthquakes two aspects of seismically induced liquefaction are discussed which are of vital engineering significance the triggering condition and the consequences of liquefaction the triggering condition is examined with respect to liquefaction analysis note being taken of the onset condition which is governed by cyclic strength consequences of liquefaction are discussed with respect to post seismic stability analysis in which the residual strength plays a major role procedures used for liquefaction analysis based on the results of in situ sounding tests are introduced and the applicability of this method for estimating associated ground settlements is discussed the evaluation of residual strength requires a better understanding of undrained sand behaviour results of extensive laboratory rests on japanese standard sand are examined and new index parameters are proposed to quantify undrained sand behaviour better the results of laboratory tests on silty sands are examined in the same way ah the results are

flowslides in stockpiled coal abstract occasional deep seated flowslides in coking coal stockpiles at the north queensland port of hay point are described the flowslides result from particularly loose placement of the light cohesionless material and saturation of the lower levels of the stockpile due to rainfall infiltration and initial moisture at placement consolidated undrained triaxial testing has been used to define the density stress conditions at which liquefaction occurs the flowslide mechanism field verification and preventative measures are briefly discussed