estimation of the time scale of the geomorphologic instantaneous unit hydrograph from effective streamflow velocity the greatest difficulty in applying the geomorphologic instantaneous unit hydrograph is the estimation of the time scale of the hydrologic response of a basin we derive the time scale from the effective streamflow velocity of the highest order stream and the spatial distribution of velocity throughout the stream network the latter is described by a dimensionless geomorphologic function with a single shape parameter the proposed method is applied to some italian basins

liquid absent aqueous fluid inclusions and phase equilibria in the system cacl2naclh2o abstract raman spectra and microthermometric data are reported for a new class of aqueous fluid inclusions in quartz from the bushveld complex the inclusions which are approximated by the system cacl2 nacl h2o hold special interest because they display the following properties 1 1 the inclusions do not contain a liquid phase at room temperature but they homogenize to an aqueous liquid at elevated temperatures 2 2 initial melting occurs at a reaction point at 29 c rather than at the cacl2 nacl h2o eutectic point at 52 c as is generally the case for fluid inclusions approximated by this system 3 3 ice is absent in the subsolidus assemblage despite the high h2o contents of the inclusions an aqueous liquid is generated upon heating through decomposition of incongruently melting hydrate daughter minerals 4 4 the most abundant minerals in the subsolidus assemblages are antarcticite cacl2 6h2o and a second hydrate that may be a new mineral probably a polymorph of cacl2 4h2o and 5 5 the fluid compositions fall outside the compositional limits defined by previous studies of natural fluid inclusions the inclusions are characterized by a high ca na ratio and a very high concentration of total dissolved solids greater than 52 wt aqueous fluid inclusions that do not contain a liquid phase at ambient temperature may be commonly overlooked or misinterpreted as mineral inclusions the liquid absent aqueous inclusions from the bushveld complex are spatially associated with a second type of fluid inclusion comprised of antarcticite halite vapor and liquid at 20 c the two types of inclusions have similar bulk compositions but they differ radically in melting behavior because their compositions lie on opposite sides of a subsolidus join given the topology of the cacl2 nacl h2o phase diagram small variations in bulk composition in the vicinity of a phase boundary or subsolidus join can result in large differences in the initial melting temperature equilibrium melting sequence and phase proportions at 20 c conversely significant constraints on fluid composition may be derived from qualitative observations of the equilibrium melting sequence

modelling complex flood flow evolution in the middle yellow river basin china summary flood routing processes in the middle yellow river basin are complex since they consist of three types of flood bidirectional convergent and divergent flood flows between the main channel and its tributaries we propose three computation schemes to simulate the complex flood routing a simple scheme for a single main channel with no tributary or backwater an improved schemes for convergent or divergent flow at the confluence and an improved scheme for bidirectional flow the schemes are examined by analyzing seven historical flood events and three scenarios of flood routing in the middle yellow river basin the model was calibrated and validated based on the simulation of three different types of flood as compared with the observed hydrographs the results show that the model is able to simulate flood routing processes efficiently for the study river with nash sutcliffe indices falling in the range 0 75 0 91 the model demonstrates that flood routing during historical flood events 1962 2003 in the middle yellow river was altered under boundary condition changes the shape of the hydrographs changed from high and thin to low and wide which was accompanied by a delayed occurrence and extended duration of peak flow after the 1960s moreover these trends were intensified after the early 1980s backwater resulted from divergent flows and bidirectional flood flows an analysis of combined boundary conditions shows that flood wave volume has the strongest impact on flood duration peak discharge and water level the time of occurrence of peak discharge and the magnitude of backwater river bed slope has the second strongest impact on flood duration and the magnitude of backwater channel roughness has the second strongest impact on peak discharge and water level

complete dynamic modeling calibration for the thurwieser rock avalanche italian central alps abstract few rock avalanches have been witnessed and no exact real time description is available the 2 5 m m 3 punta thurwieser rock avalanche september 2004 italian central alps is a unique event for which many quantitative observations have been gathered this is the first case ever of a natural rock avalanche being recorded on video and for which an almost exact value of the total time duration from initial detachment to final deposition is available the landslide travelled over 2 9 km from its source partially in a glacial environment the initial failure and the time for the complete evacuation of the source area were studied and assessed by a series of photos the mean front velocities along the path have been estimated from the video the final geometry and the characteristics of the deposit have been obtained by gps measurements aerial photos field surveys and laboratory tests a quasi 3d continuum dynamic analysis of the landslide motion has been performed assuming both a voellmy and a frictional rheology in the model dan 3d for the first time the landslide front velocities have been used for back analyses and calibration of the rheological parameters together with the final shape and thickness of the deposit and its developing extension the dynamic flow resistance parameters initially calibrated with dan were adopted and validated in dan 3d showing good consistency they are consistent with the existing database for calibrated landslides of similar type and scale flow velocities on the path segment underlain by glacial deposits up to 55 65 m s 1 are more accurately predicted by adopting a frictional rheology up to 50 55 m s 1 with zero pore pressure and a 26 friction angle than by a voellmy rheology up to 40 45 m s 1 both observations and modelling show that glacial ice plays a substantial role in increasing the rock avalanche mobility

extracting source characteristics and dynamics of the august 2010 mount meager landslide from broadband seismograms 1 seismic methods can substantially improve the characterization of the dynamics of large and rapid landslides such landslides often generate strong long period seismic waves due to the large scale acceleration of the entire landslide mass which according to theory can be approximated as a single force mechanism at long wavelengths i apply this theory and invert the long period seismic waves generated by the 48 5 mm3 august 2010 mount meager rockslide debris flow in british columbia using data from five broadband seismic stations 70 to 276 km from the source i obtain a time series of forces the landslide exerted on the earth with peak forces of 1 0 1011 n the direction and amplitude of the forces can be used to determine the timing and occurrence of events and subevents using this result in combination with other field and geospatial evidence i calculate an average horizontal acceleration of the rockslide of 0 39 m s2 and an average apparent coefficient of basal friction of 0 38 0 02 which suggests elevated basal fluid pressures the direction and timing of the strongest forces are consistent with the centripetal acceleration of the debris flow around corners in its path i use this correlation to estimate speeds which peak at 92 m s this study demonstrates that the time series recording of forces exerted by a large and rapid landslide derived remotely from seismic records can be used to tie post slide evidence to what actually occurred during the event and can serve to validate numerical models and theoretical methods

high temperature fluid inclusions and the role of the biotite granodiorite in mineralization at the panguna porphyry copper deposit bougainville papua new guinea

formation of native iron in sediment contaminated magma i a case study of the hanekammen complex on disko island west greenland abstract for the first time a compositional range of native iron bodies is described in a cogenetic series of sediment contaminated volcanic rocks from the tertiary west greenland basalt province the iron bearing rocks occur in a high level composite intrusion the hanekammen complex reaction between a tholeiitic parent magma with 11 mgo and carbonaceous al2o3 rich shale took place in a reservoir 3 km below the paleosurface and created magmatic layering with basaltic magma overlain by less dense andesitic magma the contaminated rock series bears a strong imprint of assimilation but very little fractional crystallization which implies that the two processes were not intimately coupled in the present case most of the iron was formed at depth in a range of fo2 from 10 13 atm 1200 c to 10 16 atm 1100 c as determined by the p distribution between solid iron and magma this is far below the graphite gas cco buffer at the estimated pressure 800 bars and suggests a high hydrogen fugacity together iron in basalt and andesite form a general trend defined by co versus ni concentrations that reflects the degree of assimilation the amount of immiscible sulphide liquid and the degree of reduction in order of decreasing importance the zoning of single iron grains reflects the dynamics of their growth and to some extent subsequent homogenization and reaction with the magma weakly zoned iron spherules in viscous andesite were formed and remained in situ whereas iron grains in basalt settled through the layered magma and developed strong zoning all iron types contain co rich domains

copper rich fluid inclusions in pyroxenes from the guide copper mine a satellite intrusion of the palabora igneous complex south africa a copper sulfide bearing feldspathic pyroxenite diatreme at the abandoned guide copper mine 5 km northwest of the main palabora complex transvaal province republic of south africa contains euhedral cumulate pyroxenes with primary fluid inclusions these inclusions contain an aqueous silicate liquid which on cooling crystallized pyroxene and k feldspar leaving a residual potassium and sodium bicarbonate chloride brine highly charged with copper and sulfur some of the inclusions on heating show evidence of developing two immiscible liquids which quenching suggests could be carbonate and silicate liquids a residual aqueous component was also present in these inclusions when they cooled from these primary inclusions and secondary aqueous inclusions representing just the copper rich brine it is possible to reconstruct a detailed cooling history of the diatreme which demonstrates that the copper sulfides were deposited from a residual hydrothermal fluid

fluid inclusions in apatite from jacupiranga calcite carbonatites evidence for a fluid stratified carbonatite magma chamber carbonatites of the jacupiranga alkaline carbonatite complex in sao paulo state brazil were used to investigate mineral fluid interaction in a carbonatite magma chamber because apatite showed a marked discontinuity between primary fluid inclusion rich cores and fluid inclusion poor rims sylvite and burbankite apatite pyrite chalcopyrite and ilmenite are the common phases occurring as trapped solids within primary fluid inclusions and reflect the general assemblage of the carbonatite the apatite cores had higher sr and ree concentrations than apatite rims due to the presence of fluid inclusions into which these elements partitioned a positive cerium anomaly was observed in both the core and rim of apatite crystals because oxidised ce4 partitioned into the magma the combined evidence from apatite chemistry fluid inclusion distribution and fluid composition was used to test the hypotheses that the limit of fluid inclusion occurrence within apatite crystals arises from 1 generation of a separate fluid phase 2 utilization of all available fluid during the first stage of crystallization 3 removal of crystals from fluid rich magma to fluid poor magma 4 an increase in the growth rate of apatite or 5 escape of the fluids from the rim of the apatite after crystallization the findings are consistent with fractionation and crystal settling of a carbonatite assemblage in a fluid stratified magma chamber secondary fluid inclusions were trapped during a hydrothermal event that precipitated an assemblage of anhedral crystals strontianite carbocernaite barytocalcite barite and norsethite pyrophanite magnesian siderite and baddeleyite ancylite ce monazite ce and allanite the sr and ree rich nature of the secondary assemblage and lack of a positive cerium anomaly indicate that hydrothermal fluids have a similar source to the primary magma and are related to a later carbonatite intrusion

major volatiles from a north atlantic morb glass and calibration to he a size fraction analysis the analysis of major volatiles in a north atlantic mid ocean ridge basalt morb glass has been performed using a new procedure based on the analysis of several size fractions of one single sample it enables us to separate the contributions of volatiles from the glass phase from the vesicle gas phase and eventually gas adsorbed on the grain surface the vesicle composition mole fractions obtained upon crushing is 0 94 co2 0 002 h2 0 06 h2o volatiles extracted from the glass at 1150 c are 9 7 10 6 mol g 1 co2 156 10 6 mol g 1 h2o the gases released at 500 c are mostly adsorbed contaminants but contribute marginally to the total amount except for numerous organic compounds which are destroyed at higher temperature when previous noble gas data for the same sample are considered one obtains the evidence that 1 the heco2 ratio does not fractionate between glass 4 1 10 5 and vesicles 4 6 10 5 and 2 water is not quantitatively degassed from morb glasses the ratio he co2 h2o of 10 4 2 4 13 for primitive magma has to be confirmed by further results to be considered as a typical value for a morb source

spatial and temporal variations in rockfall determined from tls measurements in a deglaciated valley switzerland steep u shaped valleys produced by glaciation are commonly eroded by rockfall in this study we investigate modern and long term power law predicted rates of rock wall retreat in a deglaciated valley our emphasis is on the 5 2 km2 calcareous cliffs covering in the lauterbrunnen valley switzerland terrestrial laser scans were collected during nine field campaigns over 18 months to provide a continuous coverage of most of the valley walls results indicate a total of 122 rockfalls with volumes ranging between 0 06 0 01 and 119 34 1 07 m3 different size groups of rockfall events were correlated with environmental factors e g freeze thaw cycles temperature precipitation and seismicity using a linear regression with variable lag times of 0 6 months the highest correlation factor r 0 6 p 0 08 90 significance level is observed for freeze thaw cycles and rockfall events smaller than 1 m3 with a 2 month delay between temperature extremes and rockfall frequency magnitude relationships for rockfall events were calculated to predict less frequent larger rockfall events that did not occur during the observation period a monte carlo analysis was applied to the frequency magnitude relationship to evaluate the sensitivity of results to their stochastic nature an average power law exponent of 1 71 0 09 was calculated using linear regression the calculated exponents are similar to other studies in calcareous rock settings conducted over different observation durations finally we determine an average total eroded volume of 2 0 0 01 0 6 103 m3 yr and a corresponding long term power law predicted cliff retreat rate of 0 39 0 02 0 12mm yr

pattern of cryospheric seismic events observed at ekstrom ice shelf antarctica mobility of glaciers such as rapid retreat or disintegration of large ice volumes produces a large variety of different seismic signals thus evaluating cryospheric seismic events e g changes of their occurrence in space and time allows to monitor glacier dynamics we analyze a one year data span recorded at the neumayer seismic network in antarctica events are automatically recognized using hidden markov models in this study we focused on a specifc event type occurring close to the grounding line of the ekstrom ice shelf observed waveform characteristics are consistent with an initial fracturing followed by the resonance of a water filled cavity resulting in a so called hybrid event the number of events detected strongly correlates with dominant tide periods we assume the cracking to be driven by existing glacier stresses through bending voids are then filled by sea water exciting the observed resonance in agreement with this model events occur almost exclusively during rising tides where cavities are opened at the bottom of the glacier i e at the sea ice interface

characterization of alpine rockslides using statistical analysis of seismic signals 1 seismic data analysis is a powerful tool for remote characterization of rock slope failures here we develop quantitative estimates of fundamental rockslide properties e g volume based solely on data from an existing regional seismic network we assembled a data set of twenty known rockslides in the central alps with volumes between 1 000 and 2 000 000 m3 and analyzed their corresponding seismograms common signal characteristics include emergent onsets slowly decaying tails and a triangular spectrogram shape the main component of seismic energy is contained in frequencies below 3 4 hz while higher frequency signals may be caused by block impacts location estimates were generated using automatic arrival time picks and resulted in a mean location error of 10 9 km a linear relationship for the detection limit of a rockslide as a function of volume was identified for our seismic station network to estimate rockslide volume runout distance drop height potential energy and fahrboschung angle of reach we extracted five simple metrics from each seismogram signal duration peak value of the ground velocity envelope velocity envelope area risetime and average ground velocity using multivariate linear regression the combination of duration peak envelope velocity and envelope area best estimated event parameters with r2 values ranging between 0 8 and 0 88 three new rockslides were then used to validate our method and volume runout drop height and potential energy were estimated within the correct order of magnitude when provided with a suitable data set of rockslide events our method can be easily adapted to other regions and seismic networks

discrimination between earthquakes and chemical explosions by multivariate statistical analysis a case study for switzerland a data set of 43 confirmed earthquakes and 42 explosions 1 3 m l 3 8 is analyzed by multivariate statistical analysis the explosion events include quarry blasts and explosions detonated for seismic experiments as well as an explosion of an ammunition storage site the events of this training data set are mainly located in the alpine mountains and central switzerland with the seismic sources having excellent distance r 300 km and azimuthal coverage for the recording stations multivariate statistical analysis is used to derive general discriminant functions based on regional waveform data for the training set the discriminant functions are then tested for consistency on the events of the training data set with the result that 97 of these events are correctly identified by the multivariate discriminant functions of the total training data set 17 is classified as ambiguous cases based on marginal discriminant functions the method is subsequently applied to an extended data set including nighttime events from 1992 1996 which are hence regarded as earthquakes and a set of presumed explosions from the years 1984 1997 for central switzerland the events of the extended data set can clearly be identified with the discriminant functions derived from the training data set the identification rate is lower for other regions in switzerland which can be related to tectonic units for these regions considered to have a laterally homogeneous crust a linear correction term in the discriminant function providing for station corrections can be found that significantly decreases the misidentification rate online material table of earthquake and explosion events manuscript received 11 may 2001

the relationship between bulk mass momentum and short period seismic radiation in catastrophic landslides the relationship between bulk mass dynamic properties of catastrophic landslides and the generation of short period seismic waves is investigated with a particular focus on the momentum of the landslide mass and the envelope of high frequency seismograms twelve very large landslides that occurred in different geological settings worldwide between 1999 and 2014 are selected for study based on the existence of detailed descriptions of their force histories determined from long period seismic waves frequency lower than 0 1 hz as well as the availability of nearby high quality short period seismic recordings a high average correlation 0 94 is found between the modulus of the landslide momentum and the envelope of the high frequency seismograms band passed filtered between 3 and 10 hz recorded on nearby stations the best correlation is seen during the acceleration phase of each landslide comparatively poor average correlation 0 57 is found between the modulus of the landslide force and the seismogram envelopes a possible scaling between the momentum and the amplitude of short period radiation is investigated the maximum amplitudes of short period seismograms for the nine best recorded landslides are corrected for local attenuation and correlated with the maximum momentum of the landslides the nine data points scatter around a best fitting line that defines a nearly linear relationship between momentum and peak short period radiation it is hypothesized that bulk mass momentum linearly modulates landslide processes that generate short period seismic waves but that the efficiency of short period radiation is highly variable between landslides

synthetic fluid inclusions in natural quartz iii determination of phase equilibrium properties in the system h2o nacl to 1000 c and 1500 bars phase equilibria in the system h2o nacl have been determined to 1000 c and 1500 bars using synthetic fluid inclusions formed by healing fractures in inclusion free brazilian quartz in the presence of the two coexisting immiscible h2o nacl fluids at various temperatures and pressures petrographic and microthermometric analyses indicate that the inclusions trapped one or the other of the two fluids present or mixtures of the two salinities of the two coexisting phases were obtained from heating and freezing studies on those inclusions which trapped only a single homogeneous fluid phase results of the present study are consistent with previously published data on the h2o nacl system at lower temperatures and pressures and indicate that the two phase field extends well into the p t range of most shallow magmatic hydrothermal activity as a consequence chloride brines exsolved from many epizonal plutons during the process of second boiling should immediately separate into a high salinity liquid phase and a lower salinity vapor phase and produce coexisting halite bearing and vapor rich fluid inclusions this observation is consistent with results of numerous fluid inclusion studies of ore deposits associated with shallow intrusions particularly the porphyry copper deposits in which halite bearing and coexisting vapor rich inclusions are commonly associated with the earliest stages of magmatic hydrothermal activity

dynamics of the bingham canyon mine landslides from seismic signal analysis joint interpretation of long and short period seismic signals generated by landslides sheds light on the dynamics of slope failure providing constraints on landslide initiation and termination and on the main phases of acceleration and deceleration we carry out a combined analysis of the seismic signals generated by two massive landslides that struck the bingham canyon mine pit on 10 april 2013 inversion of the long period waveforms yields time series for the bulk landslide forces and momenta from which we deduce runout trajectories consistent with the deposit morphology comparing these time series with the short period seismic data we are able to infer when and where major changes take place in landslide momentum along the runout path this combined analysis points to a progressive fracturing of the masses during acceleration indicates that deceleration starts the moment they reach the pit floor and suggests that the bulk movement is stopped by a topographic barrier

seismicity of rockfalls and avalanches at three cascade range volcanoes implications for seismic detection of hazardous mass movements abstract this study reviews seismograms from 14 rockfalls and avalanches of moderate to large volume 10 4 to 10 7 m 3 at mount st helens mount adams and mount rainier in the cascade range of washington to investigate how variations in source volume source materials track materials and failure modes affect avalanche seismicity the largest signals were generated by rockfalls at mount st helens and debris avalanches at mount rainier that initiated as block failures at mount st helens several rockfalls that originated as block failures near the crater rim descended slopes with similar profiles and appear to show a linear or nearly linear relation between source volume and seismogram amplitude those that fell over an extended period of time were poorly recorded at the reference seismic station and did not show this correlation multiple seismograms from three of the four instrumentally recorded debris avalanches at mount rainier indicate a tendency of unstable slopes there to fail progressively a pattern that has important implications for the mass movement hazard at mount rainier seismic evidence shows that the little tahoma rock fall avalanches in december 1963 occurred on 6 december over a week earlier than previously reported mass movements that have been seismically detected span the spectrum of rapid flowage events from water surges and debris flows to dry rock debris ice and snow avalanches the success in identifying and in some cases locating these events in near real time demonstrates that local and regional seismic networks can play a valuable role in reducing hazards from large rapid mass movements

frequency and hazard of large rock avalanches in the central southern alps new zealand forty two rock avalanche deposits with volumes ranging from a chosen lower threshold of 1 10 6 m 3 up to 500 10 6 m 3 have been identified in a 10 000 km 2 area of the central southern alps new zealand the observed frequency of one per 244 yr over 10 250 yr is biased by erosion a nearly complete sample of the past 1 700 yr indicates a frequency of 1 per 94 yr on the average the largest rock avalanche in any century is 56 10 6 m 3 and in any millennium 103 10 6 m 3 at about one per century most large rock avalanches are probably triggered by large earthquakes and only a few by large storms the risk of rock avalanche debris reaching a specified distance from a source of known elevation is given by a simple stochastic model locally calibrated to assess rock avalanche hazard

analysis of rock fall and rock fall avalanche seismograms in the french alps this study reviews seismograms from 10 rock fall events recorded between 1992 and 2001 by the permanent seismological network sismalp in the french alps a new seismic magnitude scale was defined which allowed us to compare and classify g round motion vibrations generated by these alpine rock falls each rock fall has also been cha racterized by its ground motion duration t30 at an epicentral distance of 30 km no relation was found between rock fall parameters fall height runout distance volume potential energy and rock fall s eismic magnitudes derived from seismogram amplitudes on the other hand the signal duration t30 shows a rough correlation with the potential energy and the runout distance highlighting the co ntrol of the propagation phase on the signal length the signal analysis suggests the existence of at le ast two distinct seismic sources one corresponding to the initial rupture associated with an elastic r ebound during the detachment and the other one generated by the rock impact on the slope although the fall phenomenon includes other complex processes fragmentation of the block interaction with topography plastic deformation during and after impact 2d finite element simulations of thes e two seismic sources are able to retrieve the main seismogram characteristics

geomorphology and kinematic wave based hydrograph derivation geomorphology based instantaneous unit hydrographs have been proposed by several engineers as a tool to produce runoff hydrographs from rainfall for ungauged watersheds a difficulty in applying the geomorphology based instantaneous unit hydrographs is the determination of travel time that is actually a hydraulic problem in this paper kinematic wave theory is used to analytically determine the travel times for overland and channel flows in a stream ordering subbasin system the resultant instantaneous unit hydrograph is a function of the intensity of rainfall excess hence the linearity restriction of the unit hydrograph theory is relaxed in applying the instantaneous unit hydrographs for hydrograph simulation the model deals with temporally nonuniform rainfall through convolution integration of the instantaneous unit hydrographs applied to the rainfall excess of varying intensities with time the proposed model is tested by comparing the simulated and observed hydrographs of an example watershed for several rainstorms with good results sensitivity of surface runoff unit hydrographs to the model parameters is also investigated

classification of seismic signals at villarrica volcano chile using neural networks and genetic algorithms each volcano has its own unique seismic activity the aim of this work is to construct a system able to classify seismic signals for the villarrica volcano one of the most active volcanoes in south america since seismic signals are the result of particular processes inside the volcano s structure they can be used to forecast volcanic activity this paper describes the different kinds of seismic signals recorded at the villarrica volcano and their significance three kind of signals were considered as most representative of this volcano s activity the long period the tremor and the energetic tremor signals a classifier is implemented to read the seismic registers at 30 second intervals extract the most relevant features of each interval and classify them into one of the three kinds of signals considered as most representative of this particular volcano to do so 1033 different kinds of 30 s signals were extracted and classified by a human expert a feature extraction process was applied to obtain the main characteristics of each of them this process was developed using criteria which have been shown by others to effectively classify seismic signals based on the experience of a human expert the classifier was implemented with a multi layer perceptron mlp artificial neural network whose architecture and training process were optimized by means of a genetic algorithm this technique searched for the most adequate mlp configuration to improve the classification performance optimizing the number of hidden neurons the transfer functions of the neurons and the training algorithm the optimization process also performed a feature selection to reduce the number of signal features optimizing the number of network inputs the results show that the optimized classifier reaches more than 93 exactitude identifying the signals of each kind the amplitude of the signals is the most important feature for its classification followed by its frequency content the described methodology can be used to classify more seismic signals to improve the study of the activity of this volcano or to extend the study to other active volcanoes of the region

automatic discrimination among landslide explosion quake and microtremor seismic signals at stromboli volcano using neural networks in this article we report on the implementation of an automatic system for discriminating landslide seismic signals on stromboli island southern italy this is a critical point for monitoring the evolution of this volcanic island where at the end of 2002 a violent tsunami occurred triggered by a big landslide we have devised a supervised neural system to discriminate among landslide explosion quake and volcanic microtremor signals we first preprocess the data to obtain a compact representation of the seismic records both spectral features and amplitude versus time information have been extracted from the data to characterize the different types of events as a second step we have set up a supervised classification system trained using a subset of data the training set and tested on another data set the test set not used during the training stage the automatic system that we have realized is able to correctly classify 99 of the events in the test set for both explosion quake landslide and explosion quake microtremor couples of classes 96 for landslide microtremor discrimination and 97 for three class discrimination landslides explosion quakes microtremor finally to determine the intrinsic structure of the data and to test the efficiency of our parametrization strategy we have analyzed the preprocessed data using an unsupervised neural method we apply this method to the entire dataset composed of landslide microtremor and explosion quake signals the unsupervised method is able to distinguish three clusters corresponding to the three classes of signals classified by the analysts demonstrating that the parametrization technique characterizes the different classes of data appropriately

collapse at the eastern eiger flank in the swiss alps on 13 june 2006 parts of the eastern flank of the eiger peak in the swiss alps collapsed leading to a major rock fall the unstable spur on this flank is made up of several blocks that move relative to one another instability was initiated by a block at the rear that acted as a wedge and triggered motion of the other blocks landslides are a significant natural hazard in mountainous regions1 and are often triggered by external factors such as earthquakes rainfall permafrost melting or retreat of glaciers2 a large landslide occurred in the swiss alps on 13 july 2006 when portions of an immense rock spur on the eastern flank of the eiger peak3 collapsed here we use field observations and terrestrial laser scanning data to record and quantify the relative motion along the various blocks of rock that form this spur the data show that during the year of observation the blocks moved relative to one another by up to tens of metres along fractures that can be related to pre existing planes of weakness rates of motion and deformation were high throughout july 2006 particularly in the northern part of the spur that partially collapsed on 13 july the rates decreased considerably during the subsequent months although a slight increase was noted in june and july 2007 these observations are consistent with instability of the spur initiated by subsidence of a single block at the rear which acted as a wedge and disintegrated over time owing to loss of lateral confinement

automated identification location and volume estimation of rockfalls at piton de la fournaise volcano since the collapse of the dolomieu crater floor at piton de la fournaise volcano la reunion in 2007 hundreds of seismic signals generated by rockfalls have been recorded daily at the observatoire volcanologique du piton de la fournaise ovpf to study rockfall activity over a long period of time automated methods are required to process the available continuous seismic records we present a set of automated methods designed to identify locate and estimate the volume of rockfalls from their seismic signals the method used to automatically discriminate seismic signals generated by rockfalls from other common events recorded at ovpf is based on fuzzy sets and has a success rate of 92 a kurtosis based automated picking method makes it possible to precisely pick the onset time and the final time of the rockfall generated seismic signals we present methods to determine rockfall locations based on these accurate pickings and a surface wave propagation model computed for each station using a fast marching method these methods have successfully located directly observed rockfalls with an accuracy of about 100 m they also make it possible to compute the seismic energy generated by rockfalls which is then used to retrieve their volume the methods developed were applied to a data set of 12 422 rockfalls that occurred over a period extending from the collapse of the dolomieu crater floor in april 2007 to the end of the undervolc project in may 2011 to identify the most hazardous areas of the piton de la fournaise volcano summit

real time detection location and characterization of rockslides using broadband regional seismic networks we propose a new real time approach to detect locate and estimate the volume of rockslides by analyzing waveforms acquired from broadband regional seismic networks the identification of signals generated by rockslides from other sources such as natural and or induced earthquakes is accomplished by exploiting the ratio between local magnitudes ml and duration magnitudes md we found that signals associated with rockslides have ml md 0 8 while for earthquakes ml md 1 in addition we derived an empirical relationship between md and rockslide volumes obtaining a preliminary characterization of rockslide volume within seconds after their occurrence the key points of this study are presented by testing the hypothesis on a recent rockslide event that occurred in northern italy we discuss also the potential evolution of the methodology for early warning and or rapid response purposes

geology and copper sulphide mineralization of the salmagorskii ring igneous complex kola peninsula nw russia the salmagorskii igneous complex represents a rare example of the carbonatite body of the phalaborwa complex in south peralkaline rocks containing significant copper sulphide minafrica contains one of the world s largest copper deposits eralization presented by chalcopyrite djerfisherite and cubanite but contrary to many other similar intrusions it is chardata on the geological structure of the complex and the copper acterized by the lack of niobium mineralization versulphide apatite mineralization related to its foidolitic peralkaline woerd 1986 eriksson 1989 on the other hand even rocks have been obtained from drilling in recent years the sub economic copper sulphide ores except for phalsequence of rocks dunite clinopyroxenite melilitolite ijolite urtite aborwa are rather uncommon in alkaline rocks and melteigite carbonatite forms a perfect concentric zoning within the carbonatites this paper presents the first data on copper pluton indicating that fractional crystallization was the predominant mineralization from mafic peralkaline rocks of the salpetrogenetic process copper sulphide mineralization formed at the magorskii complex post magmatic stage when recrystallization processes within earlier alkaline ultramafic ring igneous complexes in the kola ijolite and melteigite took place under the influence of a fluid rich alkaline province kukharenko et al 1965 as well as in co2 h2o alkalis s p cu and cl other regions woolley 1987 kogarko et al 1995 vasiliev zolotukhin 1995 are usually concentrically zoned pipe like intrusions in which ultramafic rocks dunite or clinopyroxenite occupy the central parts of the complexes and melilitolites with foidolites surround

automatic classification and a posteriori analysis of seismic event identification at soufriere hills volcano montserrat abstract seismic energy radiation at soufriere hills volcano montserrat is made up by various types of transient signals which are distinguished by the montserrat volcano observatory mvo in different classes with respect to their characteristics and or origin there are five fundamental classes i e volcano tectonic events regional events long period events hybrid events and rockfalls identification and classification of these transients which have been hitherto carried out manually by various staff members yield important information for the assessment of the state of the volcano system in the frame of the multimo project we proposed the application of artificial neural networks ann for the classification of these kind of data in order to handle large data sets and to achieve reproducible results emulating the expert s analysis using the manual routine classification as a priori information we obtained a fair performance of such an automatic processing with 70 of the automatic classifications being consistent with the original ones from an analysis of the misclassified events however we found that for most of them the original a priori classification was incorrect in this study we first revised manually the original a priori classification based on a data set of 6000 events we carried out a reanalysis of the seismic traces recorded at different seismic stations then using this new information we trained and tested the ann obtaining a successful classification in ca 80 of records particularly the automatic classification was excellent in the identification of rockfalls and volcano tectonic events among the misfits we observe the erroneous attribution of long period and hybrid events to rockfalls this may be partly explained by the fact that signals addressed to as rockfalls contain frequently contributions of various sources overall the failure in the classification between some types of transients highlights the problem of the concurrent activation and or unclear separation of distinctive sources from which the signals stem we conclude that the automatic classification with ann is a powerful tool for handling large data masses as well as for the a posterior analysis of the consistency of the classification problem

seismic signals associated with landslides and with a tsunami at stromboli volcano italy in this article we analyze the seismic signals produced by two landslides that occurred at the stromboli volcano on 30 december 2002 recorded by both broadband and short period seismic stations located in the 2 5 22 km distance range from the source for both landslides the characteristics of the low frequency seismograms indicate a complex time history in the release of seismic energy the first landslide occurred over the submerged part of the northwest sector of the volcano and had associated a large amplitude low frequency pulse representative of the abrupt detachment of a large mass lower amplitude phases in the following 3 minutes possibly indicate minor detachment events the highest amplitude low frequency signals are well described by a single force source model the second mass failure episode is also characterized by a complex source and can be interpreted as a multiple event with a less abrupt onset and at least four detachments occurring during 4 5 minutes and producing low frequency signals synthetic seismograms generated by a shallow single force located in the submerged area of sciara del fuoco and directed upslope fit well the first low frequency seismic pulse recorded at stromboli and panarea by three component stations from this simulation we estimated the force exerted by the first mass failure the estimate of the volume through two different procedures gives values in the range of 1 0 1 5 million m3 and about 14 million m3 respectively the landslides which involved both the submarine and the subaerial northwest flank of the volcano produced a tsunami that struck the coast of stromboli island and in a few minutes reached the other islands of the aeolian archipelago three broadband seismic stations installed on land about 100 m from the coastline at panarea island located 20 km southwest of stromboli recorded very long period seismic signals produced by the tsunami waves analysis of these signals gives invaluable information on the spectral content and propagation properties of tsunami waves and on their interaction with the ground at a short distance from the coast synthetic tsunami waves obtained by a landslide source model and taking into account the bathymetry of the sea surrounding stromboli and panarea islands fit the observed phenomena and the experimental data very well manuscript received 19 november 2003

the thurwieser rock avalanche italian alps description and dynamic analysis a rock avalanche of about 3 106 m3 detached from the south east flank of the punta thurwieser ridge italian central alps on the 18th of september 2004 due to the characteristics of the moving material i e rock debris ice snow and the path of propagation e g presence of a glacier the mass was able to rapidly cover long distances about 3000 m among the possible causes of the event attention is mainly focused on permafrost degradation and changes in glacier extension due to global warming in the present work the dynamics of the event and the role played by characteristics of the propagation path are numerically investigated with the rash3d code based on a continuum mechanics approach results obtained with two rheological hypotheses frictional and voellmy are compared and discussed in particular it emerges that 1 the use of a voellmy rheology with a reduced friction angle on the glacier is necessary to reproduce the dynamics of the thurwieser event and 2 a lack in knowledge of geometrical and geomechanical information may lead to wrong interpretations of the event and inaccurate calibration of numerical models

dynamics of the bingham canyon rock avalanches utah usa resolved from topographic seismic and infrasound data the 2013 bingham canyon mine rock avalanches represent one of the largest cumulative landslide events in recorded u s history and provide a unique opportunity to test remote analysis techniques for landslide characterization here we combine aerial photogrammetry surveying topographic reconstruction numerical runout modeling and analysis of broadband seismic and infrasound data to extract salient details of the dynamics and evolution of the multi phase landslide event our results reveal a cumulative intact rock source volume of 52 mm3 which mobilized in two main rock avalanche phases separated by 1 5 h we estimate the first rock avalanche had 1 5 2 times greater volume than the second each failure initiated by sliding along a gently dipping 21 highly persistent basal fault before transitioning to a rock avalanche and spilling into the inner pit the trajectory and duration of the two rock avalanches were reconstructed using runout modeling and independent force history inversion of intermediate period 10 50 s seismic data intermediate and shorter period 1 50 s seismic data were sensitive to intervals of mass redirection and constrained finer details of the individual slide dynamics back projecting short period 0 2 1 s seismic energy we located the two rock avalanches within 2 and 4 km of the mine further analysis of infrasound and seismic data revealed that the cumulative event included an additional 11 smaller landslides volumes 104 105 m3 and that a trailing signal following the second rock avalanche may result from an air coupled rayleigh wave our results demonstrate new and refined techniques for detailed remote characterization of the dynamics and evolution of large landslides

probabilistic earthquake location in complex three dimensional velocity models application to switzerland 1 we present a new approach to determine precise and reliable hypocenter locations in the tectonically complex region of switzerland a three dimensional 3 d p wave velocity model to be used for earthquake relocation is obtained by simultaneously inverting arrival times of local earthquakes for hypocenter locations and 3 d p wave velocity structure a 3 d p wave velocity model derived from controlled source seismology css is used as an initial reference model the final 3 d model thus combines all available information from both css and local earthquake data the probabilistic nonlinear formulation of the earthquake location problem includes a complete description of location uncertainties and can be used with any kind of velocity model in particular the combination of nonlinear global search algorithms such as the oct tree importance sampling with probabilistic earthquake location provides a fast and reliable tool for earthquake location the comparison of hypocenter locations obtained routinely by the swiss seismological service sed to those relocated in the new 3 d velocity model using a probabilistic approach reveals no systematic shifts but does exhibit large individual shifts in some epicenter locations and focal depths we can attribute these large shifts in part to large uncertainties in the hypocenter location events with a low number of observations 8 and no observation within the critical focal depth distance typically show large location uncertainties improved hypocentral locations particularly for mine blasts and earthquakes whose routine hypocenter locations had been questionable confirm that improved velocity model and probabilistic earthquake location yield more precise and reliable hypocenter locations and associated location uncertainties for switzerland

automatic detection of avalanches and debris flows by seismic methods the road along the oshli hillside in the west fjords region of iceland is one of the most hazardous roads in iceland due to avalanches rockfalls and debris flows the road has little traffic but nevertheless traffic accidents caused by the severe conditions at the site are common a number of avalanche tracks are found on the hillside in some of these tracks avalanches occur more frequently than in others when there is an avalanche threat avalanches generally flow over many tracks in a short time monitoring vibrations in the tracks with the highest avalanche frequency can indicate when avalanches start flowing down the hillside in a snowstorm and avalanche hazard can then be declared with the specific site indicated the same methodology can be used for rockfalls and debris flows which are strongly affected by weather conditions and typically occur in clusters based on this knowledge a research project was initiated in february 1996 with the objective of developing an automatic system based on seismic measurements to detect and analyze avalanches on the oshli hillside and to instantly

slope instabilities in dolomieu crater reunion island from seismic signals to rockfall characteristics 1 the seismic signals of hundreds of rockfalls within dolomieu crater piton de la fournaise volcano reunion island have been analyzed to investigate a possible link between physical rockfall generating processes and associated seismic signal features moreover indirect observation of rockfalls via the seismic signals they generate can provide useful data for studying volcanoes and the temporal variations of their structure an increase in the number of rockfall events and their volumes might be an indicator of structural weakness and deformation of the volcano associated with potential eruptive activity the study focuses on a 10 month period following the 6 april 2007 crater floor collapse within dolomieu crater from may 2007 to february 2008 for granular flows a scaling law is revealed between seismic energy and signal duration a semiempirical approach based on both analytical analysis and numerical simulation of these flows shows that a similar scaling law exists between the difference of potential energy computed for an event and its propagation times and also emphasizes the effect of local topography on this scaling law simulated and observed data were compared to evaluate the proportion of potential energy dissipated in the form of seismic waves and confirm a direct link between the seismic energy and potential energy of a given granular flow the mean ratio of seismic to potential energy is of the order of 10 4 comparable to the range of values observed in previous studies a simple method based on these ratios is proposed to estimate the volumes of rockfalls from their seismic signal observed seismic energy and the frequency of rockfalls decreased at the beginning of the studied period and reached a stable level in july thus suggesting a postcollapse relaxation time of dolomieu crater structure of about 2 months from seismic signal analysis which is confirmed by deformation data the total rockfall volume over the study period is estimated to be 1 85 mm3

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

contamination of seismicity catalogs by quarry blasts an example from istanbul and its vicinity northwestern turkey abstract scientists have proposed two fault systems of different ages in the sea of marmara the thrace eskisehir fault zone of early miocene early pliocene age and the north anatolian fault zone of late pliocene recent age different seismicity rates and extensions of these faults onto land near istanbul have been suggested one of the reasons for these differences is the contamination of seismicity catalogs by seismic events from quarries operated in istanbul and its vicinity including gaziosmanpasa cebeci and kemerburgaz catalca omerli gebze and hereke in this study we investigated waveforms of 179 seismic events 1 8

kinematic subsurface stormflow this paper builds on the analysis of henderson and wooding 1964 in comparing simplified models of subsurface stormflow for the case of a sloping soil mantle in which the hydraulic conductivity is constant throughout it is shown that models based on a kinematic wave formulation may be good approximations for those based on the extended dupuit forchheimier assumptions for values of the nondimensional parameter 4i cos k sin2 less than about 0 75 in terms of predicting both water table profiles and subsurface stormflow hydrographs by using this critical value of the range of values of slope angle and saturated hydraulic conductivity for which the kinematic approximation is valid can be specified a comparison is made with slope angles and hydraulic conductivities at field sites where subsurface stormflow has been shown to be an important component of catchment storm response it is concluded that the kinematic approximation may be useful for cases of practical interest

large glass inclusions in plagioclase phenocrysts and their bearing on the origin of mixed andesitic lavas at toliman volcano guatemala irregularly shaped large and clear lac glass inclusions are present in plagioclase phenocrysts in several andesitic lavas erupted from toliman volcano guatemala their morphology is different from densely spaced fine grained glass inclusions that form concentric zones in dusty or cellular textured plagioclase phenocrysts the large size of lac inclusions make them suitable for microprobe analysis and average bulk compositions are presented for glasses in 30 phenocrysts from eight lava samples their compositions are rhyolitic and in disequilibrium or out range anderson 1976 with respect to whole rock and groundmass glass compositions lac inclusions typically occur in large tabular plagioclase phenocrysts with relatively uniform sodic compositions an 40 54 compositions of feldspar phenocrysts not containing lac inclusions range from an 41 to an 81 petrographic and chemical data support a primary origin for lac glasses suggest mixing of mafic and silicic magmas and also constrain a mechanism for magma mixing rapid growth of plagioclase and entrapment of lac glass occurs during mixing in a vapor rich silicic liquid under low degrees of undercooling these conditions are possibly produced in a high level magma body such as that envisioned by huppert et al 1982 where replenishment and subsequent crystallization of a hydrous magma induces density instability and mixing with the resident magma

seismic recordings of landslides caused by typhoon talas 2011 japan 1 large deep seated landslides occurred in nara wakayama and mie prefectures of western japan when typhoon talas passed through the region on september 3 4 2011 signals of large landslides have been recorded by seismic networks around the world and overall force estimates have been previously determined for large landslides using long period waves this study focuses on the high frequency waveforms and presents signals of 18 landslides caused by typhoon talas 2011 the location of the landslides can be determined by a seismological back projection technique and these locations correlate with the observed surface features we have found that the volumes of the landslide correlated with an energy parameter derived from the seismic records

simple scaling of catastrophic landslide dynamics catastrophic landslides involve the acceleration and deceleration of millions of tons of rock and debris in response to the forces of gravity and dissipation their unpredictability and frequent location in remote areas have made observations of their dynamics rare through real time detection and inverse modeling of teleseismic data we show that landslide dynamics are primarily determined by the length scale of the source mass when combined with geometric constraints from satellite imagery the seismically determined landslide force histories yield estimates of landslide duration momenta potential energy loss mass and runout trajectory measurements of these dynamical properties for 29 teleseismogenic landslides are consistent with a simple acceleration model in which height drop and rupture depth scale with the length of the failing slope

understanding the rapidity of subsurface storm flow response from a fracture oriented shallow vadose through a new perspective abstract velocity and celerity in hydrologic systems are controlled by different mechanisms efforts were made through joint sample collection and the use of hydrographs and tracers to understand the rapidity of the subsurface flow response to rainstorms on hourly time scales three deep subsurface flows during four natural rainstorm events were monitored the results show that 1 deeper discharge was observed early in responding rainfall events and yielded a high hydrograph amplitude 2 a ratio index k reflecting the dynamic change of the rainfall perturbation intensity in subsurface flow might reveal inner causal relationships between the flow index and the tracer signal index most values of k were larger than 1 at the perturbation stage but approximated 1 at the no perturbation stage and 3 for statistical analysis of tracer signals in subsurface flows the total standard deviation was 17 2 11 9 7 4 and 3 5 at perturbation stages and 4 4 2 5 1 1 and 0 95 at the non perturbation stage for observed events these events were 3 7 times higher in the former rather than the later reflecting that the variation of tracer signals primarily occurred under rainfall perturbation thus we affirmed that the dynamic features of rainfall have a key effect on rapid processes because besides the gravity mechanical waves originating from dynamic rainfall features are another driving factor for conversion between different types of rainfall mechanical energy a conceptual model for pressure wave propagation was proposed in which virtual subsurface flow processes in a heterogeneous vadose zone under rainfall are analogous to the water hammer phenomenon in complex conduit systems such an analogy can allow pressure in a shallow vadose to increase and decrease and directly influence the velocity and celerity of the flow reflecting a mechanism for rapid subsurface hydrologic response processes in the shallow vadose zone

continuous hmm based seismic event classification at deception island antarctica this paper shows a complete seismic event classification and monitoring system that has been developed based on the seismicity observed during three summer antarctic surveys at the deception island volcano antarctica the system is based on the state of the art in hidden markov modeling hmm techniques successfully applied to other scenarios a database that contains a representative set of different seismic events including volcano tectonic earthquakes long period lp events volcanic tremor and hybrid events that were recorded during the 1994 1995 and 1995 1996 seismic surveys was collected for training and testing simple left to right hmms and multivariate gaussian probability density functions with a diagonal covariance matrix were used the feature vector consists of the log energies of a filter bank that consists of 16 triangular weighting functions that were uniformly spaced between 0 and 20 hz and the first and second order derivatives the system is suitable to operate in real time and its accuracy for this task is about 90 on the other hand when the system was tested with a different data set including mainly lp events that were registered during several seismic swarms during the 2001 2002 field survey more than 95 of the recognized events were marked by the recognition system

melt inclusion investigation of the volatile behaviour in historic alkali basaltic magmas of etna crystallization paths of basaltic 1763 eruption and hawaiitic 1865 and 1329 eruptions scoria from etna were deduced from mineralogy and melt inclusion chemistry the volatile behaviour was investigated through the study of melt inclusions trapped in the phenocrysts and those of the whole rocks and the matrix glasses the results from the 1763 eruption point to the early crystallization of olivine fo 81 7 from a water rich alkaline basalt with high cl 1750 2000 ppm and s 2100 2400 ppm concentrations the hawaiitic melt inclusions trapped in olivine fo 74 salite and plagioclase are characterized by a decrease in cl k2o and s k2o ratios in each investigated system there is good correlation between k2o and p2o5 in the whole rocks cl ranges from 980 to 1680 ppm from basaltic to hawaiitic lavas whereas s 110 136 ppm remains low cl and s behaviour in the 1763 magma suggests an early degassing stage of cl and s with co2 and a water rich gaseous phase for a pressure close to 100 mpa consistent with a permanent outgassing at the summit craters of etna during the eruption the sulphur remaining in the hawaiitic liquid is lost and the degassing of chlorine is limited such a degassing model can be extended to the 1865 and 1329a d eruptions

analyzing high frequency seismic signals generated during a landslide using source discrepancies between two landslides abstract high frequency seismic signals are generated during landslides and can be analyzed to obtain detailed information regarding landslide dynamics however a better understanding of the physical process that produces such high frequency signals is required the two massive landslides that occurred on april 11 2013 in the bingham canyon mine pit utah usa generated low and high frequency seismic signals using the low frequency signals we inverted the force time functions of the two events and estimated their dynamics we used the signals generated by the two events and filtered in three frequency bands to obtain the source discrepancies between the two events by analyzing these source discrepancies we found that the low and medium frequency signals were generated due to the bulk movement of sliding material furthermore the medium frequency signals contained information regarding small particle impacts along the sliding path the high frequency 1 3 hz signals are controlled by small scale process of sliding materials and are sum of stochastic phenomena this clarification of the source of the high frequency signals is expected to improve the analyses of seismic signals generated during landslides

incorporating subsurface flow mechanism into geomorphology based iuh modeling abstract surface and subsurface runoff processes on hillslopes are quite different in nature nevertheless the geomorphological instantaneous unit hydrograph giuh simulates runoff using only the surface flow mechanism in this study the giuh model was revised to consider both the surface and subsurface flow processes kinematic wave approximation was used to estimate the mean value of the travel time probability distributions for runoff in surface flow regions and channels and darcy s law was adopted to estimate the runoff travel time in subsurface flow regions based on the linear system assumption the hydrologic response of a watershed is the superposition of the hydrologic responses resulting from the surface flow and subsurface flow of the watershed the iuh can adequately reflect the variation of surface flow roughness and hydraulic conductivity an example watershed was selected to test the capability of the revised model the simulated hydrographs obtained using the original and revised models were basically in good agreement with the observed hydrographs however significant improvement of the simulation was found in the recession limb of the simulated hydrograph because flood recession was dominated by the subsurface flow process

automatic detection of alpine rockslides in continuous seismic data using hidden markov models data from continuously recording permanent seismic networks can contain information about rockslide occurrence and timing complementary to eyewitness observations and thus aid in construction of robust event catalogs however detecting infrequent rockslide signals within large volumes of continuous seismic waveform data remains challenging and often requires demanding manual intervention we adapted an automatic classification method using hidden markov models to detect rockslide signals in seismic data from two stations in central switzerland we first processed 21 known rockslides with event volumes spanning 3 orders of magnitude and station event distances varying by 1 order of magnitude which resulted in 13 and 19 successfully classified events at the two stations retraining the models to incorporate seismic noise from the day of the event improved the respective results to 16 and 19 successful classifications the missed events generally had low signal to noise ratio and small to medium volumes we then processed nearly 14 years of continuous seismic data from the same two stations to detect previously unknown events after postprocessing we classified 30 new events as rockslides of which we could verify three through independent observation in particular the largest new event with estimated volume of 500 000 m3 was not generally known within the swiss landslide community highlighting the importance of regional seismic data analysis even in densely populated mountainous regions our method can be easily implemented as part of existing earthquake monitoring systems and with an average event detection rate of about two per month manual verification would not significantly increase operational workload

the linear channel and its effect on the geomorphologic iuh abstract the instantaneous unit hydrograph iuh is derived as a function of the basin s geomorphological and physiographic characteristics inherent in the basin iuh is the response of the individual channels composing the basin the response of the individual channels is derived by solving the continuity and momentum equations for the boundary conditions defined by the iuh both the effects of upstream and lateral inflow to the channels is taken into account in the derivation of the basin s iuh the time to peak and peak response are used as a basis for comparison between the results produced by this model and those produced by a model where the channel s response is assumed to be an exponential distribution the comparisons indicate that of the approach taken in this paper is indeed accurate for example the assumptions used do not invalidate the model then the type of channel response used for the basin s iuh is significant and future efforts must be directed towards parameter estimation

interactions between rock avalanches and glaciers in the mont blanc massif during the late holocene rock avalanches are common in the mont blanc massif which is bordered by valleys with large resident and tourist populations and important highways this paper combines historical data with detailed geomorphological mapping stratigraphic observation and absolute and relative dating to interpret several deposits resulting from rock avalanching onto glaciers nineteen rock falls and rock avalanches are described ranging in volume from 10 000 m3 to 10 106 m3 they occurred between 2500 bp and ad 2007 at six sites the events at three sites miage and drus glaciers and tour des grandes jorasses are characterised by short travel distances those at brenva triolet and frebouge glaciers exhibit excessive travel distances interactions between rock avalanches and glaciers are of four types i rock avalanche triggering where glacial and paraglacial controls include debuttressing of rockwalls due to glacier thinning and retreat oversteepening of rock slopes by glacial erosion and effects of glaciers on permafrost ii rock avalanche mobility in which mobility and travel distance are modified by channelling of rock avalanche debris by moraines and valleys incorporation of ice and snow often 50 for large events and irregularities on the glacier surface iii deposit sedimentology where melting of incorporated ice transforms the final deposit by reducing its thickness typically to 5 m and debris of variable thicknesses is juxtaposed in a hummocky deposit with chaotic piles of angular rock debris and iv glacier dynamics where insulating debris deposited upon a glacier produces a debris covered glacier of different dynamics and high elevated scars can favour the formation of small glaciers

magmatic fluids in the fen carbonatite complex s e norway three different types of carbonatite magma may be recognized in the cambrian fen complex s e norway 1 peralkaline calcite carbonatite magma derived from ijolitic magma 2 alkaline magnesian calcite carbonatite magma which yielded biotite amphibole sovite and dolomite carbonatite and 3 ferrocarbonatite liquids related to 2 and or to alkaline lamprophyre magma damjernite apatite formed during the pre emplacement evolution of 2 contains inclusions of calcite and dolomite devitrified mafic silicate glass and aqueous fluid all of these inclusions have a magmatic origin and were trapped during a mid crustal fractionation event p 4 kbars t 625 c where apatite and carbonates precipitated from a carbonatite magma which coexisted with a mafic silicate melt the fluid inclusions contain water dissolved ionic species mainly nacl with minor polyvalent metal salts and in some cases co2 two main groups of fluid inclusions are recognized type a co2 bearing inclusions of approximate molar composition h2o 88 90 co 27 5 nacl 5 d 0 85 0 87 g cm3 type b co2 free aqueous inclusions with salinities from 1 to 24 wt nacleq and densities betwen 0 7 and 1 0 g cm3 more strongly saline type b inclusions salinity ca 35wt d 1 0 to 1 1 g cm3 contain solid halite at room temperature and occur in overgrowths on apatite type a inclusions probably contain the most primitive fluid from which type b fluids have evolved during fractionation of the magmatic system type b inclusions define a continuous trend from low towards higher salinities and densities and formed as a result of cooling and partitioning of alkali chloride components in the carbonatite system into the fluid phase available petrological data on the carbonatites show that the fluid evolution in the fen complex leads from a regime dominated by juvenile co2 h2o fluids during the magmatic stage to groundwater derived aqueous fluids during post magmatic reequilibration

analysis of broadband seismic recordings of landslide using empirical green s function the 2010 mount meager landslide generated strong seismic waves we used seismic signals generated by a smaller landslide that occurred within 2 min of the end of the main landslide as the empirical green s function egf with which to obtain landslide dynamics from high frequency signals we then obtained the apparent force time function of the landslide based on the egf by inverting the higher frequency seismic signals the apparent force time function shows that the source material of the main landslide came from four collapses and that the second collapse involved multiple small collapses we also used the egf to simulate the vertical seismogram recorded at one station and found that the synthesized seismogram fits the response of the bulk mobilization of the sliding materials remarkably well our study demonstrates that the use of the egf can significantly broaden quantitative insights into landslide dynamics plain language summary seismic records reflect the effects of landslide dynamics and the path of seismic waves through the earth because the calculation of the high frequency component of the effect of a wave s path through the earth requires a detailed characterization of the velocity and attenuation structure the effects of landslide dynamics can only be estimated by inverting the long period seismic signals to study the high frequency seismic signals generated from the mount meager landslide we considered the seismic signals generated by a smaller landslide as the effects of the path of seismic waves we used the seismic signals generated by the smaller landslide to simulate the signal generated by the main landslide to overcome the effects of a potential overlap in the frequency domain between signals from the bulk and those from smaller particles our results show that the seismic signals generated by a small landslide can be used to improve our understanding of those generated by the main landslide

a geomorphologic kinematic wave gkw model for estimation of floods from small alpine watersheds keywords hydrologie reference hydram article 1999 004 record created on 2005 10 11 modified on 2016 08 08

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

fluid inclusion evidence for immiscibility in magmatic differentiation abstract after a brief review of recent work on melt inclusions in diamond and in normal magmatic environments the nature of the fluid inclusion evidence for various stages of magmatic immiscibility is summarized during magmatic differentiation by crystal fractionation from originally low volatile content silicate melts yielding normal plutonic rocks through hydrous silicate melts yielding pegmatites to late stage water rich fluids yielding quartz veins and ore deposits the composition of the residual liquid changes drastically in some geologic environments this change in composition of the residual liquid may be continuous with no phase change in the fluid part of the system under most natural conditions however it is far more likely to have one or more stages in the evolution during which globules of a separate new immiscible fluid phase exsolve the term immiscibility is used here in its more general sense to refer to the existence at equilibrium of two or more non crystalline polycomponent solutions fluids differing in properties and generally in composition i believe that the great bulk of the magmatic inclusions that are being studied today have come about through the intervention of one or more such stages of immiscible fluid separation i e magmatic differentiation by fluid immiscibility examples include silicate melt dense co2 fluid silicate melt sulfide melt silicate melt silicate melt silicate melt low density vapor i e vesiculation and as presented in more detail in this paper various stages of silicate melt hydrous saline melt aqueous fluid co2 fluid immiscibility generally only parts of these stages are recorded by the trapping of fluid inclusions and the interpretation of the inclusion record is commonly ambiguous and difficult particularly that stage between hydrous silicate melts and the hydrous saline melts and aqueous solutions responsible for many ore deposits the ambiguity results mainly from problems of inclusion origin and nonrepresentative trapping within any given individual inclusion thus the probability of trapping of only one vs various amounts of two immiscible fluids or of trapping solid phases along with the fluid present severe difficulties in addition there is the almost universal superposition of various stages of trapping of fluids within any given sample these problems can only be approached by very careful petrography and analysis of optimum material combined with field data and experimental p v t x studies of pertinent systems completely unequivocal statements of the course of evolution of the fluids in such natural systems may never be possible

a two state integral balance model for soil moisture and groundwater dynamics in complex terrain a dynamical model is devised for a hydrologic system where unsaturated and saturated storage serve as the principal control on rainfall runoff and where complex topography drainage area and variable depth of moisture penetration describe the flow geometry the model is formed by direct integration of the local conservation equation with respect to the partial volumes occupied by unsaturated and saturated moisture storage respectively this yields an integral balance model in just two state variables the relationship of the dynamical model to field data in complex terrain is found through a joint probability density for terrain features this serves as a volume weighting function to construct conditional averages for the state variables and fluxes over a specified range of terrain features the scale of averaging could range from hillslopes to river basins two examples of the joint probability of terrain features altitude and aspect are demonstrated for valley ridge and appalachian plateau digital elevation models the strategy of a dynamical model formed by conditional averages of state variables with respect to terrain features is proposed as a way of simplifying the dynamics while preserving the natural spatial and temporal scales contributing to runoff response the parametric form of the storage flux or constitutive relationships for the proposed model is determined from numerical experiments in a simple hillslope flow geometry the results show that a competitive relation exists between unsaturated and saturated storage except for the lowest precipitation rates saturation overland flow is proposed to be a storage feedback relation solutions to the integral balance model are presented in terms of the phase portrait which represents all possible solution trajectories in state space the timing and magnitude of peaks in the runoff hydrograph from pulse type input events demonstrate quick flow from near stream saturated storage saturation overland flow including rejected rainfall storage feedback and late time infiltration from upslope subsurface flow