long term ground displacement observations using insar and gnss at piton de la fournaise volcano between 2009 and 2014 abstract monitoring ground surface displacement of volcanoes over a long period of time helps improve understanding of the volcano structure dynamics and mechanisms in this paper we investigate the spatio temporal behavior of the long term displacement field at piton de la fournaise volcano la reunion island by means of x band insar and gnss time series analysis from 2009 to 2014 we propose a new correction approach based on principal component analysis to mitigate the long wavelength artifact in the interferograms over the study area our results show that most of the volcanic edifice including the central cone the eastern flank and recent lava flow fields was affected by varying degrees of ground motion more importantly a widespread sector 20 km2 affected by time dependent downward and eastward motion was observed on the eastern flank of piton de la fournaise the combined analysis of insar and gnss time series and previous studies allows us to confirm that this large mobile sector on the eastern flank underwent deformation for at least 7 years following the end of the large march april 2007 eruption including a stage of transient strain from the end of eruption to february 2011 followed by a stage of steady state strain until late 2014 several possible origins including a pre existing structural discontinuity summit stress associated with magmatism and activated fault movement are explored to explain the observed widespread long term seaward motion that is considered to be direct evidence of potential flank instability

cone penetration test calibration for erksak beaufort sea sand discussion this is a discussion of a paper by the same title which appeared in volume 24 canadian geotechnical journal pp 601 610 the authors of the original paper are k been b e lingnau j h a crooks and b leach

direct simulation of random field samples from sparsely measured geotechnical data with consideration of uncertainty in interpretation random field theory has been increasingly used in probabilistic geotechnical analyses over the past few decades where a random field generator with random field parameters is needed to simulate random field samples rfss of interest estimation of random field parameters particularly correlation functions or correlation length generally requires extensive measurements however the data gathered from site characterizations are usually sparse particularly for small or medium sized projects therefore it is difficult to provide an accurate estimation on random field parameters and the random field parameters estimated and subsequently used in rfs generation might contain significant uncertainty this leads to a challenge of properly simulating rfss in consideration of such uncertainty this paper aims to address this challenge by developing a novel random field generator which is capable of directly generating rfss from sparse measurements obtained during site characterization and properly accountin

cone penetration test calibration for erksak beaufort sea sand interpretation of the cone penetration test in sands is generally based on empirical calibrations from tests in large diameter calibration chambers although interpretation of these calibration data for clean sands in terms of the state parameter is expected to be broadly applicable to other sands material specific correlations are desirable for many projects this paper describes a series of calibration chamber tests carried out on a sand dredged from the beaufort sea for construction of artificial islands this erksak sand is a uniformly graded subrounded medium grained sand with a fines content of 3 6 the testing chamber described is 1 4 m in diameter and allows independent control of vertical horizontal and back pressures on the sand sample samples of the sand were prepared by moist compaction to preserve the fines content and then back pressure saturated the chamber test data are presented and confirm that the erksak sand fits the general trends observed for other sands very well a method i

effects of silt content and void ratio on the saturated hydraulic conductivity and compressibility of sand silt mixtures the hydraulic conductivity the coefficient of consolidation and the coefficient of volume compressibility play major roles on the pore pressure generation during undrained and partially drained loading of granular soils with fines this paper aims to determine how much these soil parameters are affected by the percentage of fines and void ratio of the soil the results of a large number of flexible wall permeameter tests performed on 60 specimens of two poorly graded sands with 0 5 10 15 20 and 25 nonplastic silt are presented and discussed hydraulic conductivity measurements were done at effective confining stresses of 50 300 kpa the evaluation of the data shows that the hydraulic conductivity and the coefficient of consolidation of sands with 25 silt content are approximately two orders of magnitude smaller than those of clean sands the coefficient of volume compressibility of the sand silt mixtures is affected in a lesser degree by void ratio silt content and confining stress the influence of the degree of saturation on the laboratory measured k values is also discussed

finite element analysis of the nerlerk underwater berm failures finite element analyses have been carried out to investigate the possible causes of failure during construction of the nerlerk underwater berm a hydraulically placed sand slope designed to form

spatial variability drained and undrained deviatoric load response geotechnical properties vary in space geostatistical parameters such as the mean the standard deviation and the correlation length are characteristic for each sediment and formation history the effects of spatial variability on the drained and undrained shear response of soils are investigated using numerical parametric studies where multiple realisations are tested for selected geostatistical parameters results show that the mean undrained shear strength decreases as spatial variability and correlation length increase spatial variability prompts strain localisation along neighbouring weak zones under both drained and undrained loading heterogeneous contractive media show internal homogenisation during drained deviatoric loading and the drained shear resistance evolves towards the critical state media with higher variability and longer correlation length require higher strain to attain internal homogenisation anisotropy in spatial correlation causes anisotropy in shear strength an intermediate d

stochastic evaluation of static liquefaction in a predominantly dilative sand fill the paper investigates the potential for liquefaction in a predominantly dilative hydraulic sand fill and in particular whether pockets of loose material could have been instrumental in the failure of the nerlerk underwater berm this has been achieved stochastically by linking random field theory for modelling spatial variability with finite elements for computing geostructural response specifically a double hardening soil model has been calibrated against data from 74 triaxial tests on erksak sand for a wide range of sand states while state parameter statistics have been derived from 71 cone penetration tests from two beaufort sea sand islands multiple realisations of structural performance have then been carried out by generating univariate random fields of state parameter from which the soil model parameters have been inferred the results demonstrate that it may be possible for a predominantly dilative fill to liquefy due to the presence of semi continuous loose zones arising from deposit

the displacement field of the landers earthquake mapped by radar interferometry geodetic data obtained by ground or space based techniques can be used to infer the distribution of slip on a fault that has ruptured in an earthquake although most geodetic techniques require a surveyed network to be in place before the earthquake1 3 satellite images when collected at regular intervals can capture co seismic displacements without advance knowledge of the earthquake s location synthetic aperture radar sar interferometry first introduced4 in 1974 for topographic mapping5 8 can also be used to detect changes in the ground surface by removing the signal from the topography9 10 here we use sar interferometry to capture the movements produced by the 1992 earthquake in landers california11 we construct an interferogram by combining topographic information with sar images obtained by the ers 1 satellite before and after the earthquake the observed changes in range from the ground surface to the satellite agree well with the slip measured in the field with the displacements measured by surveying and with the results of an elastic dislocation model as a geodetic tool the sar interferogram provides a denser spatial sampling 100 m per pixel than surveying methods1 3 and a better precision 3 cm than previous space imaging techniques12 13

spatial variation in liquefaction risk basic concepts and methods of random field theory useful for characterizing distributed disordered systems are applied to a soil deposit to evaluate the spatial extent of liquefaction under typical conditions the soil deposit modelled after a site located at the wildlife management area in california is represented by a three dimensional random properties field and is subjected to multiple realizations of a space time random field of earthquake ground motion patterned after the superstition hills event of 1987 based on monte carlo analysis using a deterministic one dimensional nonlinear finite element program spatial variability of liquefaction risk is assessed and techniques for improving estimates of liquefaction risk accounting for local spatial variation are investigated les concepts et m6thodes de base de la theorie de champ aleatoire servant caracteogonriser les systemes desordonnes repartis sont appliqueogons un d pot de sol pour evaluer 1 etendue spatiale de la liquefaction dans

spatial variability of the undrained strength of clays the objective of this study is to provide a simple yet accurate procedure for the description of the spatial variability of the undrained shear strength s u of soft clays this is achieved on the basis of experimental findings and field observations of the depth dependent nature of s u the main features of the method are a linear with depth variation of the mean value and standard deviation of s u and a smooth exponential function that describes the correlation between values received by s u at different vertical locations the developed procedure is illustrated in a case study involving actual strength data two sites are selected from the general area investigated in connection with the west side highway in new york city each site is characterized by the values of s u obtained along two boreholes using field vane shear tests the results of the applied analysis verify previous findings on the vertical variability of s u and demonstrates the applicability of the present procedure in the commonly encountered situations with limited data

evaporation of groundwater from arid playas measured by c band sar salt bearing groundwater evaporates within arid playas and roughens the surface during the summer months we show that it is possible to infer the rates of evaporation of groundwater using radar backscatter measurements using an empirically derived relationship between backscatter coefficient and surface roughness a model of how surface roughness changes with a continuous process of halite crystal efflorescence and an assumed value for the salinity of the regional groundwater we calculate the volumetric rate at which the groundwater must have evaporated the method is illustrated with data from the european remote sensing 1 satellite synthetic aperture radar sensor that imaged the chott el djerid playa in southern tunisia from 1992 to 1993 independent measurements and calculations indicate that the radar method overestimates the rate of evaporation the reasons for this probably lie in the assumptions about the salt budget of the groundwater or the model of how the salt crust roughens with time

back analysis of the nerlerk berm liquefaction slides reply pressuremeter 39th canadian geotechnical conference ottawa hird c c and hassona f 1986 discussion on a state parameter for sands giotechnique 36 1 pp 123132 huntsman s r 1985 dctcrmination of ir sitlc lateral pressure of cohesionless soils by static cone penetrometer ph d thcsis university of california at berkeley berkeley ca huntsman s r m tcmell j k klejbuk l and sihinde s 1986 lateral stress measurement during cone penetration asce specialty conference on use of in situ testing in gcotcchnical engineering blacksburg va jefferies m g stewart h thomson r a a and roberts b j 1985 molikpaq deployment at tarsiut p 45 plenary session paper proceedings asce specialty confercncc on civil engineering in the arctic offshore arctic 85 san francisco mitchell d e 1984 liquefaction slides in hydraulically placed sands proceedings of 4th international symposium on landslides toronto m j o connor a n d associates 1982 an evaluation of the regional surficial geology of the southern bcaufort seas geological survey of canada report parry r h g 1971 stability analysis for low embankments on soft clays stress strain behaviour of soils roscoc memorial symposium cambridge g t foulis co henlcy on thames england sladen j a d hollander r d and k r a i n j 1985 the liquefaction of sands a collapse surface approach canadian geotechnical journal 22 4 pp 564 578

probabilistic stability analysis of a tailings dyke on presheared clay shale probabilistic slope stability analysis offers an efficient framework for logical systematic incorporation of un certainty into slope design the slow integration of probabilistic slope analyses into practice is attributed among other factors to the lack of published studies illustrating the implementation and benefits of such techniques a spreadsheet based probabilistic slope analysis methodology is applied to evaluate the stability of a section of the syncrude tailings dyke in fort mcmurray canada the dyke is approximately 44 m high and is founded on presheared clay shale the performance of the dyke is governed by uncertainties about material properties and pore water pressures starting with field and laboratory data this study demonstrates the techniques used in quantifying the various components of param eter uncertainty conducting a probabilistic assessment and estimating the probability of unsatisfactory performance the probability of unsatisfactory performance of the dyke is estimated to be 1 6 10 3 field monitoring data indicate that the dyke performance is adequate the study thus provides a first link between probability figures and perfor mance the analysis also quantifies the relative contributions of the various sources of uncertainty to the overall uncer tainty in the factor of safety

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

spatial variability of cpt parameters and silty fines in liquefiable beach sands abstractincreasing awareness of the role of spatial variability in the assessment of liquefaction susceptibility has driven the need to characterize the vertical and horizontal spatial variability

nonlinear subsidence rate estimation using permanent scatterers in differential sar interferometry discrete and temporarily stable natural reflectors or permanent scatterers ps can be identified from long temporal series of interferometric sar images even with baselines larger than the so called critical baseline this subset of image pixels can be exploited successfully for high accuracy differential measurements the authors discuss the use of ps in urban areas like pomona ca showing subsidence and absidence effects a new approach to the estimation of the atmospheric phase contributions and the local displacement field is proposed based on simple statistical assumptions new solutions are presented in order to cope with nonlinear motion of the targets

ground penetrating radar soil suitability map of the conterminous united states abstract the performance of ground penetrating radar gpr in soils strongly depends on soil electrical conductivity soils having high electrical conductivity rapidly attenuate radar energy which restricts penetration depths and severely limits the effectiveness of gpr factors influencing the electrical conductivity of soils include the amount and type of salts in solution and the clay content the ground penetrating radar soil suitability map of the conterminous united states is a thematic map showing the relative suitability of soils for gpr applications within comparatively large areas of the united states this map is based on over twenty five years of field observations made throughout the united states and soil attribute data contained in the state soil geographic statsgo database attribute data used to determine the suitability of soils include taxonomic criteria clay content salinity sodium absorption ratio and calcium carbonate content based on additional testing several gpr specific adjustments have been made this paper describes these revisions and outlines the procedures used to develop the revised map the revised map limits areas that are rated as being unsuited for gpr to saline and sodic soils reassesses calcareous and gypsiferous soils and provides a mineralogy override for soils with low activity clays this map can be used to assess the relative appropriateness of gpr for soil investigations within comparatively large areas of the conterminous united states

an analysis and comparison of observed pleistocene south carolina usa shoreline elevations with predicted elevations derived from marine oxygen isotope stages geological maps of south carolina covering 6800 km2 confirm the existence of eight preserved pleistocene shorelines above current sea level marietta 42 6 m wicomico 27 4 m penholoway 21 3 m ladson 17 4 m ten mile hill 10 7 m pamlico 6 7 m princess anne 5 2 m and silver bluff 3 m current geochronologic data suggest that these eight shorelines correlate with marine oxygen isotope stages mis as follows marietta older than mis 77 wicomico mis 55 45 penholoway mis 19 or 17 ladson mis 11 ten mile hill mis 7 pamlico mis 5 princess anne mis 5 and silver bluff mis 5 or 3 except for the mis 5e pamlico and possibly the mis 11 ladson the south carolina elevations are higher than predicted by isotope proxy based reconstructions the 4 m of total relief from the pamlico to the silver bluff shoreline in south carolina for which other reconstructions suggest an expected relief of 80 m illustrates the lack of match our results suggest that processes affecting either post depositional changes in shoreline elevations or the creation of proxy sea level estimates must be considered before using paleo sea level position on continental margins

reliability assessment of slopes with three dimensional rotated transverse anisotropy in soil properties the influence of soil variability on three dimensional 3d probabilistic slope stability analysis has been previously investigated for soils that display isotropic spatial variability features or

3d effects in seismic liquefaction of stochastically variable soil deposits the natural variability of soil properties within geologically distinct and uniform layers has been proven to greatly affect soil behaviour and to induce significant variability in the predicted response previous studies concluded that small scale heterogeneity greatly affects the liquefaction potential of saturated soil deposits and provided geotechnical design guidelines to account for the effects of various characteristics of spatial variability those studies were based on two dimensional analyses of soil liquefaction in a vertical plane assuming plane strain behaviour therefore the correlation distance of soil variability in a direction normal to the plane of analysis was implicitly taken as infinite i e no variability in the third direction in this study a monte carlo simulation approach involving generation of sample functions of non gaussian multivariate multidimensional random fields and non linear finite element analyses is used to investigate the effects of soil heterogeneity on the

the cone penetration test in sands part ii general inference of state the state parameter concept provides a new method of characterizing sand behaviour but the utility of the concept relies on the ability to measure the state parameter in situ part i of this paper demonstrated a relationship between normalized cone resistance and state parameter for monterey sand in this paper the state parameter approach is applied to data from calibration chamber tests on several sands it is shown that this approach leads to a common relationship for all the data that includes the effects of material type quantified by the slope of the steady state line the state parameter for a sand can therefore be determined in situ with a reasonable precision using a general framework of interpretation which applies to all uncemented sands la notion de parametre d etat fournit une nouvelle methode pour caracteriser le comportement des sables mais son utilite depend de la possibilite de mesurer le parametre d etat in situ la premiere partie de cet article demontre une relation entre la resist

time series mining subsidence monitoring with temporarily coherent points interferometry synthetic aperture radar a case study in peixian china peixian located in the northwest of xuzhou jiangsu province china has rich coal resources and is one of the main coal mining regions in this coastal region ground subsidence as a result of mining is one of the main causes of environmental damage in peixian using temporarily coherent points interferometry synthetic aperture radar tcpinsar which is characterized by phase unwrapping and temporary coherent points tcps 43 sentinel 1a images acquired from 4 october 2016 to 21 april 2018 were processed to generate time series ground deformations of the zsl zhang shuang lou the xz xu zhuang and the kz kong zhuang mines in the southern region of peixian the results showed that the maximum accumulated values for subsidence and velocity in the zsl mine were 418 3 mm and 188 8 mm year respectively the maximum accumulated values of subsidence in the xz mine and the kz mine reached 213 2 mm and 191 5 mm respectively the monitoring results showed that damage to buildings was consistent with underground mining activities therefore on this basis the time series subsidence of large mining areas may be monitored using tcpinsar

class a prediction of arctic caisson performance from august 1985 to march 1986 numerical predictions were made of the performance of a mobile arctic caisson subjected to ice forces a constitutive model for soil was calibrated using available laboratory data and the model incorporated within a finite element computer program features of performance predicted included maximum caisson displacement the modes of internal displacement for drained and undrained conditions whether the performance would indeed be drained or undrained and if undrained where high excess pore pressures would be found in april 1986 the caisson was subjected to large ice forces approaching the design limit and the predictions were verified on site to a remarkable degree for this problem physical models predicted an erroneous response dans la periode aout 1985 mars 1986 des predictions numeriques furent effectuees pour le comportement d un caisson arctique mobile soumis aux forces des glaces un modele constitutif pour le sol fut calibre par l emploi des donnees de la

ground penetrating radar use in three contrasting soil textures in southern ontario 26 27 ground penetrating radar gpr is a non invasive geophysical tool which can be used 28 for the identification of clandestine graves gpr operates by detecting density differences in soil 29 by the transmission of high frequency electromagnetic em waves from an antenna domestic 30 pig sus domesticus carcasses were clothed in 100 cotton t shirts and 50 cotton 50 31 polyester briefs and buried at a consistent depth at three field sites of contrasting soil texture 32 silty clay loam fine sand and fine sandy loam in southern ontario gpr was used to detect and 33 monitor the graves for a period of 14 months post burial analysis of collected data revealed that 34 gpr had applicability in the identification of clandestine graves in silty clay loam and fine sandy 35 loam soils but was not suitable for detection in the fine sandy soil studied the results of this 36 research have applicability within forensic investigations involving decomposing remains by 37 aiding in the location of clandestine graves in loam soils in southern ontario through the use of 38 gpr 39 40

evaluation of soil state from sbp and cpt a case history the cone pressuremeter test cpt is widely used to determine the in situ state of cohesionless soils however although the cpt is simple inexpensive and accurate the subsequent interpretation

problems with interpretation of sand state from cone penetration test considerable attention has been given to the inference of sand density from indirect tests particularly the cone penetration test cpt data from tests performed in large scale chambers have demonstrated that for a given sand there is an approximately unique relationship between cpt tip resistance density or void ratio and effective stress level data have been presented to support the supposition that cpt tip resistance if normalized by division by the mean effective stress is uniquely related to the difference between the current void ratio and the void ratio at the steady state at the same mean stress level the paper presents a study of chamber test data for the ticino sand and demonstrates that there is no such unique relationship for this sand use of published correlations that fail to recognize this and other potentially important factors could result in interpretations of sand state that if carried through to design could in some circumstances be catastrophic a series of flow slides tha

advanced dinsar analysis on mining areas la union case study murcia se spain the town of la union se spain is located within a metal mining area that has been exploited since the roman period this historic exploitation has left behind a high concentration of abandoned underground mining galleries currently an industrial area is subsiding due to the collapse of one of these galleries in may 1998 in this paper an advanced differential interferometry sar dinsar method called the coherent pixels technique cpt has been used to study the subsidence phenomena for two time intervals from january 1998 to december 2000 and from march 2003 to december 2004 dinsar derived deformation maps have enabled the detection and monitoring of different deformation processes that affect several locations within the study area by comparing these results with the underground mining galleries map a clear relationship between their presence and the subsidence has been proved deformation values retrieved with dinsar between april 2003 and december 2004 have been compared with the topographical leveling network measurements performed in this same period providing an absolute average difference of 0 7 cm with a standard deviation of 0 5 cm results obtained in the city of la union have shown that the advanced dinsar technique is able to provide very useful spatial and temporal deformation data for the measurement of small scale subsidence throughout short time periods this technique has enabled the temporal evolution of the phenomena in the city of la union to be studied and understanding of subsidence to be expanded beyond the limits of a deployed topographical control network in a more cost effective way than classical methods

environmental and criminal geoforensics an introduction many subdisciplines within the earth sciences make use of either geophysical instruments to investigate the subsurface environment or use analytical methods to determine the origin or provenance of geological materials these same instruments and analytical methods can be used either directly or adapted to suit the acquisition of data that pertain to a wide range of forensic science investigations such approaches as discussed below are generally not new but in recent years there has been a significant resurgence globally in the application of geological and geophysical methods to aid forensic investigations traditionally such methods were used in forensic investigations related to serious criminal cases such as terrorism murder abduction and serious sexual assaults and to a lesser extent in the investigation of cases of fraud and theft but with increasing concern into the environmental impact of human activity with the release of contaminants into the atmosphere hydrosphere and lithosphere and their potential uptake into the biosphere there has been an increased amount of environmental legislation in turn there has commonly been an increase in the costs associated with the legal discharge or disposal of wastes consequently it is unsurprising that the illegal discharge and disposal of wastes has also increased identifying the distribution impact and source of such waste materials can in part be addressed through the application of geological techniques in much the same way as used traditionally for example in the investigation of murder cases the diversification of the use of geological techniques into the investigation of environmental crime will potentially significantly increase the range of investigations in which geologists may be asked to assist but will also lead to a new array of research questions to be addressed hence the need for this special publication in this short introduction the aim is to place the current work into its broad historical context and summarize the key findings from the papers presented within this volume the papers within this special publication were presented at two separate conferences in 2010 the third international soil forensics conference held at long beach california usa and organized by the sfi group and a conference on environmental and criminal forensics organized by the forensic geoscience group of the geological society of london and held at burlington house london in december 2010

influence of spatial variability of soil young s modulus on tunnel convergence in soft soils abstract field data have shown the fact that soil spatial variability could aggravate the uncertainty of tunnel convergence d a key indicator for serviceability and safety of tunnels this paper presents a detailed numerical analysis to investigate the probabilistic response of tunnel convergence in spatially varied soft soils the soil young s modulus es is highlighted and modeled with isotropic and horizontally stratified anisotropic random fields respectively the influence of scale of fluctuation sof of the es on convergence d is discussed in detail with respect to different directions i e the vertical and horizontal directions both for and d it is observed that ignoring the spatial variability of es i e disregarding the possibility of unfavorable soft soil low stiffness soil locally around tunnel can underestimate the mean value of d the horizontally stratified anisotropic random field is more appropriate than isotropic random field in the sense of an accurate prediction especially when extreme tunnel convergence occurs in horizontally stratified anisotropic random fields the influence of horizontal and vertical sof is different on tunnel convergence the surrounding soils near tunnel crown and invert or across tunnel horizontal diameter are very critical to the tunnel convergence in addition the effect of horizontal sof x on failure probability of the calculated d exceeding the specified allowable dlim is limited when the x is larger than 4 84 times of tunnel outer diameter

assessment of soil spatial variability for linear infrastructure using cone penetration tests soil spatial variability has a significant impact on the reliability of geotechnical structures in particular the horizontal variability is important for linear infrastructure which has only lim