the fluid factor as an avo indicator castagna and smith 1994 presented a very interesting comparison of some of the different amplitude variation with offset avo indicators used in the industry today they used a worldwide sample of data to compute their examples in their paper they alluded to the fluid factor of smith and gidlow 1987 but they did not compute this attribute for their data in the following we suggest how the fluid factor can be computed and compare the results with the rp rs and a b 2 techniques we have used castagna and smith s 1994 notation

role of near bed turbulence structure in bed load transport and bed form mechanics the interactions between turbulence events and sediment motions during bed load transport were studied by means of laser doppler velocimetry and high speed cinematography sweeps u 0 w 0 w 0 which contribute negatively to the bed shear stress and are relatively rare individually move as much sediment as sweeps of comparable magnitude and duration however and much more than bursts u 0 and inward interactions u 0 w 0 when the magnitude of the outward interactions increases relative to the other events therefore the sediment flux increases even though the bed shear stress decreases thus although bed shear stress can be used to estimate bed load transport by flows with well developed boundary layers in which the flow is steady and uniform and the turbulence statistics all scale with the shear velocity it is not accurate for flows with developing boundary layers such as those over sufficiently nonuniform topography or roughness in which significant spatial variations in the magnitudes and durations of the sweeps bursts outward interactions and inward interactions occur these variations produce significant peaks in bed load transport downstream of separation points thus supporting the hypothesis that flow separation plays a significant role in the development of bed forms

discrimination between pressure and fluid saturation changes from time lapse seismic data explicit expressions for computing saturation and pressure related changes from time lapse seismic data have been derived and tested on a real time lapse seismic data set necessary input is near and far offset stacks for the baseline seismic survey and the repeat survey the method has been tested successfully in a segment where pressure measurements in two wells verify a pore pressure increase of 5 to 6 mpa between the baseline survey and the monitor survey estimated pressure changes using the proposed relationships fit very well with observations between the baseline and monitor seismic surveys 27 of the estimated recoverable hydrocarbon reserves were produced from this segment the estimated saturation changes also agree well with observed changes apart from some areas in the water zone that are mapped as being exposed to saturation changes which is unlikely saturation changes in other segments close to the original oil water contact and the top reservoir interface are also estimated and conf

approximations to seismic ava responses validity and potential in glaciological applications amplitude variation with angle ava methods establish the seismic properties of material either side of a reflective interface and their use is growing in glaciology the ava response of an interface is defined by the complex knott zoeppritz k z equations numerous approximations to which we typically assume weak interface contrasts and isotropic propagation inconsistent with the strong contrasts at glacier beds and the vertically transverse isotropic vti fabrics were associated with englacial reflectivity we considered the validity of a suite of approximate k z equations for the exact p wave reflectivity rp of ice overlying bedrock sediment and water and englacial interfaces between isotropic and vti ice we found that the approximations of aki richards shuey and fatti match exact glacier bed reflectivity to within rp 0 05 smaller than the uncertainty in typical glaciological ava analyses but only for maximum incident angle i limited to 30 a stricter limit of i 20 o ffered comparable accuracy to a hydrocarbon benchmark case of shale overlying gas chargedsand the vti compliant rugerapproximation accurately described englacial reflectivity to within rp 0 01 and it can be modified to give a quadratic expression in sin 2 i suitable for curve matching operations having shown the circumstances under which ava approximations were valid for glaciological applications we have suggested that their interpretative advantages can be exploited in the future ava interpretations

the anatomy of avo crossplots avo crossplots are a simple and elegant way of representing avo data offset variations in amplitude for reflecting interfaces are represented as single points on a crossplot of intercept and gradient the advantage of this type of plot is that a great deal of information can be presented and trends can be observed in the data that would be impossible to see with a standard offset or angle versus amplitude plot the crossplot is an ideal way of examining differences in avo responses that may be related to lithologic or fluid type variations commonly used techniques for revealing these differences include color coding samples from the crossplot and using this as an overlay to a seismic display or creating weighted or equivalent angle stacks i e linear combinations of intercept r0 and gradient g

measurements of the reynolds stress components close to a marine sand bank abstract soulsby r l 1981 measurements of the reynolds stress components close to a marine sand bank mar geol 42 35 47 observations of turbulence have been made at a height of 65 cm above the sea bed in water 42 m deep on the edge of the skerries sand bank off southwest england the observations extended over a 4 h period from the time of maximum flood velocity to slack water electromagnetic current meters were used to measure the streamwise u cross stream v and vertical w velocity components while simultaneously a conventional current meter measured the speed and direction 5 m below the water surface ratios of u2 1 2 v2 1 2 and w2 1 2 to shear velocity agreed with accepted values for laboratory and atmospheric flows near to the surface the current was found to flow across the bank while near the bed it ran nearly parallel to the isobaths consequently the bottom current was directed 480 clockwise of the surface current the azimuth of the reynolds stress uw vw near the bed lay between these directions and was directed about 60 anticlockwise of the near bed current this balanced the cross stream as well as the streamwise shear a lateral shear stress uv associated with the bank was observed taken together with previous measurements of the velocity distribution over the bank this yielded a value for lateral eddy viscosity of 1 2 105 cm2 s 1 the scale over which this acts is of the order 1 km and the value is appreciably smaller than reported values deduced for larger scales the veering of the current acts to lessen the bottom current convergence associated with coriolis and curvature effects and may contribute to lateral sorting by preferentially carrying finer sediment toward the crest of the bank the lateral eddy viscosity coefficient may be useful in assessing the diffusion of sediment on or off the bank

dendrogeomorphic assessment and sediment transfer of natural vs mining induced debris flow activity in călimani mountains eastern carpathians romania abstract during the second half of the twentieth century in the central part of the c limani mountains the mining activities for sulfur rich ore extraction and processing produced significant landscape changes sediment transfers across the affected catchments started during the mining period and are still ongoing today more than two decades after the cessation of the mining activities in 1997 subsequently neither rehabilitation works nor erosion control measures were undertaken to stabilize the spoil heap deposits and natural reforestation also material consolidation was impeded by the highly unstable talus slopes moreover little is known about the frequency of the hydrogeomorphic processes responsible for sediment transfers and their consequences dendrogeomorphic investigations grain size analyses and topographic surveys were carried out to document the history of hydrogeomorphic activity the volume of material stored behind the retention dams and the rate of sediment accumulation tree ring analysis allowed us to reconstruct ten debris flow events in the natural environment as well as in mining disturbed environment for the period 1931 2017 and 1970 2017 respectively triggering of debris flows appears related to spring and summer precipitation originating from short duration convective systems or long lasting rainfalls in these remote mining areas the reconstructed frequency of debris flows return intervals of 8 1 and 4 7 years might be explained by the rainwater accumulation on the spoil heap platform and the availability of sediments which flow down the talus and then follow the stream channels to reach one of the sediment retention reservoirs 7 4 8 4 cm y 1

avo inversion theory and practice avo inversion is an area of research which attempts to go beyond the qualitative process of avo interpretation currently used to predict the presence of gas in a sand

dynamic behavior of suspended sediment concentrations in a shallow lake perturbed by episodic wind events field experiments were conducted in lake balaton a large surface area 600 km2 but shallow mean depth 3 2 m lake in hungary to quantify the resuspension and deposition of bottom sediment due to episodic storm events measurements were made of windspeed and direction surface waves mean water velocity and suspended sediment concentration during significant wind events the computed bottom stress due to surface waves dominated that due to the mean current and therefore surface waves were assumed to be the major cause of sediment resuspension a simple model for the depth averaged suspended sediment concentration based on surface wave height was calibrated with about 10 h of data collected during one storm event and verified against 15 d of data collected at the same site the success of the suspended sediment model which assumes that the bottom sediment was noncohesive is surprising since the bottom material was composed predominantly of sediment in the clay and fine silt size ranges this fit may indicate the presence of a thin surface layer of loosely bound sediment that is continuously involved in resuspension the suspended sediment model could easily be integrated into a water quality model e g to predict light attenuation provided that lateral transport is negligible or it could be used to provide the bottom boundary condition for a more general suspended sediment transport model in which advective transport is included due to their small fall velocities finegrained particles i e those in the silt and clay size ranges are transported easily by flows an understanding of the dynamic behavior of these particles is particularly important in shallow lakes and estuaries since there they may repeatedly settle to the bot

geophysical evidence for gas hydrates in the deep water of the south caspian basin azerbaijan new 2 d seismic reflection data from the south caspian sea offshore azerbaijan document for the first time in the deep water up to 650 m of this area the presence of gas hydrates geophysical evidence for gas hydrates consists of a shallow 300 500 m below seafloor zone of pronounced high velocity 2 100 m s as compared with the surrounding sediments 1550 1600 m s this zone appears on the seismic data as a depth limited 200 m thick layer extending down the flank of an elongate structural high and displays seismic blanking effects on the sedimentary section a strong positive polarityorc 0 123u reflector marks the top of this velocity anomaly and is interpreted as the top of the gas hydrate layer similarly a high amplitudeorc 0 11u negative polarity reflector coincides with the base of the highvelocity layer and is interpreted as the base of the hydrate zone both the top and bottom of the hydrate layer approximately parallel the seafloor bathymetry and cut discordantly across the stratigraphic section suggesting that the two reflectors are thermobaric and not stratigraphic interfaces decreasing amplitude with offset at the base of the gas hydrate layer may indicate the accumulation of free gas beneath this interface these gas hydrates fall within the hydrate stability field predicted from thermobaric modeling for the south caspian basin but typically in thinner layers than would be expected from theoretical calculations the minimum predicted water depth that allows hydrate formation is 150 m and the maximum predicted thickness of the gas hydrate stability field is 1350 m q 2001 elsevier science ltd all rights reserved

comparison of avo indicators a modeling study a worldwide collection of 25 sets of velocity and density measurements from adjacent shales brine sands and gas sands was acquired with full waveform sonic dipole sonic and conventional well logging devices and or in the laboratory these data provide theoretical shale over brine sand and shale over gas sand p wave and s wave normal incidence reflection coefficients r p and r s avo intercepts a avo gradients b the avo indicators r p r s reflection coefficient difference and a b avo product the reflection coefficient difference is found to be a more universal indicator than the avo product in clastic stratigraphic intervals for shale over brine sand re flections the average r p r s tends to be near zero and relatively invariant with depth irrespective of gas sand impedance r p r s is always negative for shale over reservoir quality gas sand reflections and more negative than for the corresponding brine sand reflections in comparison the avo product may be positive near zero or negative for gas sands depend ing on the impedance contrast with the overlying shale these measurements also verify that r p r s is well approximated by a simple linear combination of a and b

the ava amplitude versus angle signature of small scale reflector topography routine amplitude versus offset or amplitude versus angle ava analysis is founded on the predicted reflectivity of a planar boundary between isotropic homogeneous half spaces yet many real boundaries of interest to hydrocarbon exploration may violate these assumptions here we evaluate consequences of boundary roughness i e small scale sub resolution topography on the reflecting boundary to find whether sub resolution topography can deceive routine ava analysis and produce misleading hydrocarbon indicators we use noise free synthetic cmp and stacked section seismograms generated with a kirchhoff integral method for offsets up to 4000 m the reflecting boundary was at 2000 m depth below a single overburden layer and comprised isolated mounds or channels sinusoidal cross section 5 40 m high and 100 750 m wide and more complex roughness simulated with seven 1 5 2 km long bathymetric profiles across modern day river beds with dune and bar features up to approximately 20 m or 20 ms twt vertical relief and 10 100 m or more lateral extent flat boundary responses were taken as the reference against which to compare waveforms and amplitudes through semblance analysis ava intercept a and slope b cross plots and inferred poisson s ratios physical properties of the media were based on shales and brine or oil sands from an offshore uk oilfield for the cmp centred on the topographic feature isolated mounds and channels produced correlated excursions of a and b from the flat boundary response by approximately 35 200 simulating the familiar background trend but sometimes oblique to it inferred poisson s ratios were around 0 3 but for some channels often fell as low as 0 2 potentially interpretable as gas sand for complex boundary topographies on a shale brine sand model ava parameters were extracted for 29 cmps 100 m apart along each of seven profiles on a cross plot they spanned the flat boundary response on a linear trend b 0 01 0 02 1 72 0 09 a similar to reported real data and a realistic mudrock trend but with outliers both above and below it that could be interpreted as real weak anomalies poisson s ratios were 0 30 0 01 between the expected values for brine and oil sand this suggests that boundary roughness may contribute to observed trends on cross plots and possibly small but potentially laterally extensive false ava anomalies may also be induced

the characteristics of blasting vibration frequency bands in jointed rock mass slope high slope and rock mass joint development are the factors for predicting and controlling blasting vibrations under open pit mining blasting vibration adversely affects the stability of jointed rock slopes thus studying the characteristics of blasting vibration frequency bands in jointed rock masses slope is an important task to ensure the safety of blasting operations in the present study vibratory ground motions were measured during blasting excavation in open pit mining and the blasting vibration frequency band characteristics of jointed rock masses and high slope were studied through the wavelet transform and response spectrum method the results demonstrated that the amplification effects of the peak particle velocity ppv and energy between different frequency bands exhibited distinguishing characteristics it was found that with the increase in elevation the ppv and energy amplification effects were the most obvious in the 0 16 hz band while they were attenuated in the 32 64 hz band furthermore the distribution of dominant frequency bands of vibration signals observed to be low and narrow and the average frequency had been reduced in the development of joints in rock masses the ppv and energy in each frequency band were attenuated and the distribution of the dominant frequency bands of vibration signals was high and wide also the average frequency had been increased and the multi modal characteristics of the responses to blasting vibrations were more obvious the rock mass structures had displayed different amplification effects on the frequency components of the blasting seismic waves finally as the effects of jointed rock masses on the blasting load responses could not be simply considered as reducing vibrations they must be analyzed using vibration theory and actual situations

prediction of velocity profiles and longitudinal dispersion in salt marsh vegetation to predict the behavior of solutes and suspended particles in wetlands it is necessary to estimate advection and longitudinal dispersion to better understand these processes measurements were taken of stem frontal area velocity vertical diffusion and longitudinal dispersion in a spartina alterniflora salt marsh in the plum island estuary in rowley massachusetts vegetation volumetric frontal area peaked at 0 067 6 0 007 cm 21 near 10 cm from the bed if the velocity profile in a dense emergent marsh canopy depends on the local balance between pressure forcing and vegetation drag the velocity will vary inversely with canopy drag i e velocity is minimum where the frontal area is maximum in fact the minimum velocity was observed at 10 cm from the bed the momentum balance therefore provides a way to predict the velocity profile structure from canopy morphology the vertical diffusion coefficient also depends on canopy characteristics such that the vertical diffusion coefficient normalized by the velocity and stem diameter had a constant value of 0 17 6 0 08 at this study site the canopy morphology also controls the longitudinal dispersion observed in this study to be 4 to 27 cm 2 s 21

mapping surface deformation in open pit iron mines of carajas province amazon region using an integrated sar analysis abstract the carajas mineral province encompasses the world s largest iron reserves with excavation carried out through open pit benching mining operations in the area have significant areas of rock mass movements and surface displacements that potentially lead to slope instabilities with risks to personnel equipment and production instabilities can be expected due to deep excavations in rock masses of low geomechanical quality blasting practices and heavy precipitation in this paper ground instabilities are monitored through an integrated sar analysis based on a data stack of 33 terrasar x images this approach was designed to monitor distinct displacement regimes ranging from small to high deformation rates and to map surface changes based on variations of radar reflectivity results were compared with field information total station prisms ground based radar geological and geomechanical maps and the approach showed to be effective for monitoring ground deformation in the region due to its capabilities synoptic view high accuracy dense grid sampling the complementary use of space based sar with field monitoring systems proved to be strategic for operational mining planning and risk assessment in this challenging environment

quantitative seismic pre stack analysis of potential gas hydrate resources in the makran accretionary prism offshore iran abstract gas hydrates are classified as a major unconventional resource and assumed to be a future potential energy source high pressures low temperature stability conditions of the hydrates restrict their occurrence to the permafrost and deep sea regions from the continental slop to the abyssal in these regions where the well information is most often absent or sparse the amplitude variation with angle ava is a common method of hydrate free gas assessment in this method various linear reflection coefficient equations are fitted to a series of data points to compute some pre stack attributes these attributes have the advantage of being an interface property rather than a layer property which makes them an easy to use characterization tool in lack of well data in recent years rock physics templates nomograms have been presented to estimate the hydrate free gas saturations solely based on these interface properties ava inversion approach was applied to the seismic data in the makran accretionary prism offshore iran to estimate the bottom simulating reflector bsr vicinity hydrate and gas saturations this inversion process included four pre stack attributes of the intercept gradient normal incidence ni and poisson reflectivity pr and was limited to the bsr estimated bsr vicinity saturations were ranged from 7 8 5 for hydrate and 5 6 5 for free gas at three representative locations accuracy of each attribute was analyzed by a synthetic modeling in this modeling the effective medium theory emt was considered to calculate the physical properties of hydrate and gas bearing sediments lithological properties and the acquisition geometry were set to the corresponding values of the field data results of the synthetic ava inversion showed that if the hydrate saturation does not exceed 30 the error of the estimation for pre stack attributes would be in acceptable range the expected estimation errors for actual attributes were derived from this synthetic modeling

human topographic signatures and derived geomorphic processes across landscapes abstract the earth s surface morphology in an abiotic context is a consequence of major forcings such as tectonic uplift erosion sediment transport and climate recently however it has become essential for the geomorphological community to also take into account biota as a geomorphological agent that has a role in shaping the landscape even if at a different scale and magnitude from that of geology although the modern literature is flourishing on the impacts of vegetation on geomorphic processes the study of anthropogenic pressures on geomorphology is still in its early stages topography emerges as a result of natural driving forces but some human activities such as mining agricultural practices and the construction of road networks directly or indirectly move large quantities of soil which leave clear topographic signatures embedded on the earth s morphology these signatures can cause drastic changes to the geomorphological organization of the landscape with direct consequences on earth surface processes this review provides an overview of the recent literature on the role of humans as a geological agent in shaping the morphology of the landscape we explore different contexts that are significantly characterized by anthropogenic topographic signatures landscapes affected by mining activities road networks and agricultural practices we underline the main characteristics of those landscapes and the implications of human impacts on earth surface processes the final section considers future challenges wherein we explore recent novelties and trials in the concept of anthropogenic geomorphology herein we focus on the role of high resolution topographic and remote sensing technologies the reconstruction or identification of artificial or anthropogenic topographies provides a mechanism for quantifying anthropogenic changes to landscape systems this study may allow an improved understanding and targeted mitigation of the processes driving geomorphic changes during anthropogenic development and help guide future research directions for development based watershed studies human society is deeply affecting the environment with consequences on the landscape therefore establishing improved management measures that consider the earth s rapidly changing systems is fundamental

influence of turbulence on bed load sediment transport this paper summarizes the results of an experimental study on the influence of an external turbulence field on the bed load sediment transport in an open channel the external turbulence was generated by 1 a horizontal pipe placed halfway through the depth ih 2 a series of grids with a clearance of about one third of the depth from the bed and extending over a finite length of the flume and 3 a series of grids with a clearance in the range 0 1 1 0 ih from the bed but extending over the entire length of the flume two kinds of experiments were conducted plane bed experiments and ripple covered bed experiments in the former case the flow in the presence of the turbulence generator was adjusted so that the mean bed shear stress was the same as in the case without the turbulence generator in order to single out the effect of the external turbulence on the sediment transport in the ripple covered bed case the mean and turbulence quantities of the streamwise component of the velocity were measured and the shields parameter due to skin friction was determined the shields parameter together with the rms value of the streamwise velocity fluctuations was correlated with the sediment transport rate the sediment transport increases markedly with increasing turbulence level

mapping ground movements in open pit mining areas using differential sar interferometry the coherent pixel technique is an advanced differential sar interferometry technique that has been used for mapping and monitoring ground movements in la union mining area murcia se spain this technique was originally used to monitor mining subsidence in la union town but unknown ground instabilities were detected in an abandoned open pit mining area nearby measured displacements have been analyzed with respect to geometrical and geological factors that play a role in ground movements then a blind test consisting on geomorphological mapping of detected deformed areas was performed in order to identify the existence of unknown active processes slope instabilities and flat accumulation areas finally a detailed analysis of these results has permitted to illustrate the advantages and disadvantages of using this technique for mapping ground movements in mining areas

using the gnss method assisted with uav photogrammetry to monitor and determine deformations of a dump site of three open pit marble mines in eliktekke region amasya province turkey the determination and monitoring of deformations that may occur in the benches of dump sites of open pit mines are important for both security and continuity of mine production the global navigation satellite system gnss is the most preferred method for deformation monitoring at dump sites while the amount of deformation 3d displacements can be determined at the points monitored by the gnss method interpretations on the cause and or areal size of the deformation may remain limited the main factors or triggering causes of slope failures at dump sites are base topography geometric dimensions width height and slope of the formed benches stiffness ratio of the dumped material and load increases caused by new dumps in the lower benches in this study uav photogrammetry and gnss were used together and the deformations at the adjacent dump site of three different open pit marble mines located in eliktekke region of amasya province in turkey were monitored the gnss method determined the points where displacements occurred and the uav photogrammetry searched for the causes of mobility at the point and its areal and volumetric sizes the uav photogrammetric results revealed that the topographic slope and overall slope inclination triggered the movement of the zones field measurements and evaluations made for this dump site showed that the current geometry should be kept where the overall slope inclination reaches 14 and not to be increased further the results support that the gnss method assisted with uav photogrammetry is a rapid and economical method to determine both the borders and volumetric sizes deformations as their causing parameters through the proposed methodology it will be possible to effectively determine the main factors causing slope failures in similar areas and to take the necessary measures on time

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

landslide detection integrated system ladis based on in situ and satellite sar interferometry measurements abstract an integrated system to analyze slope instabilities over vast areas through the intercomparison of measurements obtained by in situ and persistent scatterer ps interferometry processing of satellite synthetic aperture radar sar data is here introduced and tentatively named landslide detection integrated system ladis the persistent scatterer pair psp sar interferometry technique has been used to process high resolution sar images acquired in the 2008 2011 time span by the cosmo skymed satellite constellation available in a 40 km 40 km study area in the palermo province sicily region italy derived displacement rate estimates from cosmo skymedps measurements have been analyzed in approximately 10 of the study area for landslide research within this area according to the official landslide inventory map extremely slow to very slow landslides are dominant being favored by the presence of heterogeneous clay formations characterized by poor mechanical properties to prove cosmo skymedps displacement rates an engineering geological approach was adopted tailored to allow a continuous and rapid updating of landslide inventory maps to this aim a detailed geological field work has been performed to guarantee an independent assessment field surveys have been carried out without sharing information derived from ps data almost half 49 of the active unstable areas identified through cosmo skymedps measurements were confirmed by the field work in an additional 26 of cases the greater sensitivity of the satellite has allowed to identify movements even if very slow that did not show superficial evidence a confirmation of the great potentialities of the latest generation of satellite systems also comes from the comparison with the current official landslide inventory map updated in 2006 among the 58 of the total ps measurements that have been used to contour the landslides in remote 84 3 falls outside the polygons of the failures detected in the existing maps which implies a significant percentage of data to be associated to new landslides or extension of pre existing landslides advantages and drawbacks of exploiting cosmo skymed x band sar data to study landslides over wide areas through the proposed approach are finally discussed

spatiotemporal monitoring of surface motions using dinsar techniques integrated with geological information a case study of an iron mine in the amazon region using terrasar x and radarsat 2 data instabilities are extremely common in the iron open pit mines located in the carajas mineral province the world s largest iron reserves located in the brazilian amazon due to deep excavations in rock products of low geomechanical quality heavy precipitation and blasting practices mining operations in the area present surface displacements that potentially lead to slope instabilities with several risks personnel equipment mining infrastructure etc this paper presents the results related to the n5e mine based on dinsar time series dts and persistent scatterer interferometry psi using a temporal series of 33 stripmap terrasar x sm tsx images and geological information provided from a 3d photointerpretation of an sm tsx and ultra fine radarsat 2 uf rst stereo pair calibrated with field data measurement point dts psi results were compared with in situ geodetic survey information total station prism measurements and showed good agreement indicating that most of the mine can be considered stable during the period of the tsx coverage the highest accumulated displacements were spatially related to a thematic unit mapped as a landfill for other sectors of the mine lower deformation rates were related to photointerpreted lineaments related to the carajas fault system suggesting that geological structures can play a key role in controlling some surface displacements the investigation demonstrated that the strategy based on the use of dts and psi techniques integrated with geological data provided a synoptic view of the deformation process that affected the mine the approach was relevant for ground displacements monitoring of the study area with dinsar results compared with in situ geodetic measurements showing good statistical correlation

monitoring of remedial works performance on landslide affected areas through ground and satellite based techniques abstract differential interferometric synthetic aperture radar dinsar techniques have repeatedly proved to be an effective tool for built environments monitoring in areas affected by geological hazards this paper describes how the coherent pixel technique cpt approach has been successfully applied to assess the response of an unstable slope to the different phases of remedial works following a landslide event the cpt technique was performed on 59 cosmo skymed images obtained between may 2011 and august 2016 and centred on the quercianella settlement a small hamlet of livorno municipality tuscany italy where the reactivation of a dormant shallow slide had occurred in march 2011 and hereafter a geotechnical intervention designed with the aim of mitigating the risks has been conducted from august 2013 lasting thirteen months the time series of cpt results show a deformation pattern with sudden accelerations up to 21 mm in few months corresponding to the beginning of the interventions during which the area has been excavated to install a drainage well followed by mild decelerations resulting from the stabilization of the area after the conclusion of the works in particular the integration of ground based subsurface monitoring inclinometers and piezometers and dinsar superficial data has provided consistent results for landslide characterization and helped defining the state of activity and the areal distribution of the sliding surface moreover the performance of remedial works in the landslide affected area has been observed showing stabilization in the upper part of the hamlet and the ongoing movement in the lower part the combined monitoring system also led the geotechnical company in charge of remedial works to design further stabilization works in order to preserve buildings and roads in the moving area therefore the integration of remote sensing techniques and in situ instruments represents a timely and cost efficient solution for intervention works monitoring opening new perspectives on designing engineering solutions for the stabilization of unstable slopes

a comparison between methods that discriminate fluid content in unconsolidated sandstone reservoirs three seismic attributes commonly used to predict pore fluid and lithology are the fluid factor f poisson impedance pi and lambda rho we evaluated the pore fluid sensitivity of these attributes with both well log and seismic data in tertiary unconsolidated sediments from the gulf of mexico where sand and shale are the only expected lithologies while the sensitivity of one attribute versus another to discriminate pore fluid is often debated in the literature the sensitivities of the three attributes are not independent but can be traced back to the fluid factor which is a function of the p and s wave normal incident reflection coefficients interestingly the fluid factor which is a reflectivity attribute at the top of a hydrocarbon saturated reservoir is basically independent of the shale properties above the reservoir it is a function of the brine and hydrocarbon impedances of the reservoir the next attribute poisson impedance is thenequal to the fluid factor times the sum o