monitoring landslide displacements by using ground based synthetic aperture radar interferometry application to the ruinon landslide in the italian alps 1 synthetic aperture radar sar data are collected by a ground based radar system forming the synthetic aperture by the sliding of the antennas on a linear rail coherent sar processing converts the raw data into a complex image the phase of each image pixel contains information on the target sensor distance and can be exploited as a ranging tool the interferometric technique based on the comparison between paired and coherent sar images taken at different times permits the quantitative extraction of this information thus allowing the monitoring of the morphological changes the portable device used in this application was developed by the joint research center ispra italy specifically for measurements in the field it is known as linear sar and it is able to provide 17 ghz measurements with a 2 8 m synthetic aperture a measurement campaign lasting about 1 week was performed between july and august 2000 for monitoring superficial displacements at the ruinon landslide a 30 million m3 rockslide in the italian alps two sequences of interferograms are presented and discussed the interpretation of the sequences has allowed us to derive multitemporal deformation maps of the test area thus showing the entire displacement field of those landslide sectors characterized by higher radar reflectivity and coherence displacement rates up to 1 2 mm h 1 have been measured with a pixel resolution of 5 m and a measurement precision of 0 75 mm the results have been validated by using ground truth data obtained through automatic extensometers and topographic measurements discrepancies are limited to a few millimeters

simulation of the supersar multi azimuth synthetic aperture radar imaging system for precise measurement of three dimensional earth surface displacement the supersar imaging system a novel multi azimuth synthetic aperture radar sar system capable of detecting earth surface deformation in three dimensions from a single satellite platform has recently been proposed in this paper we investigate the feasibility of detecting precise 3 d surface displacement measurements with the supersar imaging system using a point target simulation from this simulation we establish both a relationship between the interferometric sar phase and the across track displacement and a relationship between the multiple aperture interferometry phase and the along track displacement based on the supersar imaging geometry the theoretical uncertainties of the supersar measurement are analyzed in the across and along track directions and the theoretical accuracy of the 3 d displacement measurement from the supersar system is also investigated according to both the decorrelation and the squint and look angles in the case that the interferometric coherence is about 0 8 and that five effective looks are employed the theoretical 2 d measurement precision values are about 3 67 and 6 35 mm in the across and along track directions respectively and the theoretical 3 d measurement precision values for 3 d displacement are about 4 05 4 56 and 3 45 mm in the east north and up directions respectively the result of this study demonstrates that the supersar imaging system is capable of measuring the 3 d surface displacement in all directions with subcentimeter precision

large scale mapping of gully affected areas an approach integrating google earth images and terrain skeleton information abstract the gully erosion process poses a threat to the ecological environment land management and agronomic productivity although current studies on gully feature mapping conducted at hill slope or catchment scales have yielded good performances the approach for large scale gully affected areas mapping is still challenging this study demonstrates a novel approach inspired by the relationship between gully distribution and surface runoff the google earth ge images and aster gdem were applied to explore the feasibility of open data source in large scale gully mapping the ge images were used for the initial classification based on object based image analysis and random forest model the drainage network obtained from the digital elevation model was generated as the terrain skeleton which controls the gully bodies the rule sets for removing commission and omission errors were developed based on the spatial relationship between the segments and drainage networks the experiment was conducted at one of the most serious erosion regions in the loess plateau with an area of 154 000 km2 owing to the novel integration strategy of image and topographic features the mapping results prove the approach extracts gully affected areas efficiently with acceptable accuracy overall accuracy is 78 80 even within the complex gully zone compared with visual interoperation the proposed approach provides a potential tool to erosion research community that could also be of interest to geomorphologists and policy makers

composite rock slope kinematics at the current randa instability switzerland based on remote sensing and numerical modeling abstract kinematic analysis of slope instabilities in brittle rock is crucial for understanding the reaction of the rock mass to external forcing factors in steep terrain inaccessibility often limits collection of relevant data and remote sensing techniques must be applied this is the case at the current randa rock slope instability in southern switzerland where a total volume of about 5 6 million m3 moves at a rate of up to 30 mm yr a large portion of the unstable rock mass is exposed in an 800 m high inaccessible cliff the main scarp of the may 1991 rock slope failure between 2005 and 2007 a comprehensive suite of remote sensing techniques including photogrammetry lidar and gb dinsar was combined with 3d geodetic measurements to characterize the rock mass structure and displacement patterns photogrammetry and lidar data were measured simultaneously from a helicopter using a system allowing for oblique view angles which provided optimal observations of the steep rock cliff we used these datasets to map large scale structures and extract their orientation and minimum persistence as well as to characterize the 1991 failure scarp the northern part of the may 1991 failure surface shows a transition from stepped planar sliding at the base to failed rock bridges in the center to tensile failure close to the vertical head scarp kinematic analysis of the discontinuity sets in the currently moving rock mass shows that both toppling and translational sliding are feasible failure mechanisms toppling is more likely for steep faces above 2200 m whereas translational failure is more likely in the lower portion of the instability interpretation of gb dinsar displacement maps revealed similar kinematic behavior and also allowed identification of a basal rupture zone and lateral release plane bounding the instability displacement vectors derived from geodetic surveying provided new insights into the 3d kinematic behavior of the instability all information extracted from different data sets were integrated in a conceptual model which was then investigated with 2d numerical simulation using the discontinuum code udec the numerical models were able to reproduce the hypothesized kinematic behavior well

structurally controlled instability damage and slope failure in a porphyry rock mass abstract rock slopes fail through structurally controlled mechanisms global circular failures or complex mechanisms depending on structural patterns and rock mass damage here structural geology rock mass characterisation terrestrial laser scanning tls ground based radar interferometry gb insar and finite element modelling are integrated to explore relationships between structure damage and global slope failure at mt gorsa trentino italy there a porphyry quarry has been excavated in complex strongly anisotropic rhyolitic ignimbrite rock masses the slope was affected by a major rockslide in 2003 and undergoes continuing instability site investigations and gb insar monitoring revealed that the 2003 failure was a roto translational rockslide involving about 400 000 m3 of disrupted rock structural analysis of tls and field data shows that the slope is affected by widespread structurally controlled mechanisms sliding toppling strain localization in kink bands the non obvious relationships between structurally controlled and global roto translational slope failure mechanisms are investigated by characterising rock mass damage in different slope sectors a new approach to quantify rock mass damage by mapping the geological strength index and interpreting its topographic signatures in tls point clouds is presented a persistent geological marker is systematically mapped in tls point clouds and correlations between attitude variability statistics and rock mass damage are established providing an efficient assessment tool rock mass damage increases in kinematic domains affected by structurally controlled instability gsi 35 40 and is maximum in areas of ongoing global instability gsi 15 20 the 2003 rockslide occurred inside a damaged rock mass zone with gsi

deformation of stromboli volcano italy during the 2007 eruption revealed by radar interferometry numerical modelling and structural geological field data abstract the activity of stromboli volcano is characterized by very low energy explosions occurring every 10 15 min throwing out lava above the crater rim during 2007 the volcano showed an anomalous activity in which new effusive vents developed 27 february and 9 march and a major explosion took place on 15 march this paper presents an integrated study based on a structural geological field survey interferometric radar monitoring and numerical modelling on the deformations of the upper nw flank of the volcano sciara del fuoco sdf the field survey carried out during the 2007 events shows the development of mainly ne striking fissures and fractures on the northern part of the upper sdf in january 2007 the ground based synthetic aperture radar gb insar installed on the flank of the sdf showed a progressive acceleration of movement on the ne crater preceding the eruption of 27 february 2007 by the first half of february the acceleration also involved the upper portion of the sdf and on 27 february the eruption started with the opening of new vents and deformation rates higher than the measurement capability of the radar device on 8 9 march 2007 the gb insar highlighted the formation of a bulge on the nw sector of the sdf preceding the opening of an additional vent to understand the deformation pattern recorded during the eruption a numerical simulation was carried out by using the flac 3d code based on the integration of all the data the deformations observed in the pre effusive phase before 27 february seem to be related to the intrusion of a sw ne striking dyke the bulging recorded before the 9 march vent opening is instead to be associated with the intrusion of a sub horizontal sill

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

remote sensing as tool for development of landslide databases the case of the messina province italy geodatabase abstract landslide geodatabases including inventories and thematic data today are fundamental tools for national and or local authorities in susceptibility hazard and risk management a well organized landslide geo database contains different kinds of data such as past information landslide inventory maps ancillary data and updated remote sensing space borne and ground based data which can be integrated in order to produce landslide susceptibility maps updated landslide inventory maps and hazard and risk assessment maps italy is strongly affected by landslide phenomena which cause victims and significant economic damage to buildings and infrastructure loss of productive soils and pasture lands in particular the messina province southern italy represents an area where landslides are recurrent and characterized by high magnitude due to several predisposing factors e g morphology land use lithologies and different triggering mechanisms meteorological conditions seismicity active tectonics and volcanic activity for this area a geodatabase was created by using different monitoring techniques including remote sensing e g sar satellite ers1 2 envisat radarsat 1 terrasar x cosmo skymed data and in situ measurements e g gbinsar damage assessment in this paper a complete landslide geodatabase of the messina province designed following the requirements of the local and national civil protection authorities is presented this geo database was used to produce maps e g susceptibility ground deformation velocities damage assessment risk zonation which today are constantly used by the civil protection authorities to manage the landslide hazard of the messina province

identifying rock slope failure precursors using lidar for transportation corridor hazard management abstract in the thompson and fraser river valleys rockfall and rockslides are a hazard for railway traffic in the region in june 2013 a 2600 m 3 rockslide occurred in the white canyon causing damage to infrastructure and interruption to service in the year preceding this failure the slope was monitored using terrestrial light detection and ranging lidar as part of the railway ground hazards research program initiative the purpose of this study is to evaluate a hazard management strategy for transportation corridors exposed to steep slopes involving the identification of rockfall precursors prior to significant slope failures for this failure deformation was observed in the seven months preceding collapse with an accelerating period occurring in the final 28 days a distinct pattern of smaller rockfalls was observed around the perimeter of the deforming rock block as well as loss of surficial material over the slides tension crack this study shows that with lidar monitoring precursors to rock slope failures can be identified allowing for better rock slope hazard management by focusing attention on areas with the highest probability of failure

integration of advanced monitoring and numerical modeling techniques for the complete risk scenario analysis of rockslides the case of mt beni florence italy on december 28 2002 a landslide occurred on the eastern flank of mt beni florence italy on a slope where jointed basalts and ophiolitic breccias overlie mesozoic limestones calcari a calpionelle formation the collapse was preceded by several forewarning signals the evolution of the slope deformation was the most important of them and its analysis was the starting point for a risk scenario assessment in fact during the management of the emergency period which began on april 13 2002 in effort to evaluate the actual extension of the landslide the distribution of the displacements within the mass its kinematical characteristics and its spatial and temporal evolution data obtained by means of geomechanical surveys laboratory analyses geotechnical investigations geophysical surveys seismic and gbinsar monitoring systems distometric and automatic and distinct element numerical modeling were integrated thus it has been possible to provide public authorities with all necessary information to plan suitable measures for risk management and reduction after the event the study was completed with a runout back analysis that highlighted successes and failures of the predictive investigations

field monitoring of the corvara landslide dolomites italy and its relevance for hazard assessment the corvara landslide is an active slow moving rotational earth slide earth flow located uphill of the village of corvara in badia one of the main tourist centres in the alta badia valley in the dolomites province of bolzano italy present day movements of the corvara landslide cause national road 244 and other infrastructures to be damaged on a yearly basis the movements also give rise to more serious risk scenarios for some buildings located in front the toe of the landslide for these reasons the landslide has been under observation since 1997 with various field devices that enable slope movements to be monitored for hazard assessment purposes differential gps measurements on a network of 47 benchmarks has shown that horizontal movements at the surface of the landslide have ranged from a few centimetres to more than 1 m between september 2001 and september 2002 over the same period vertical movements ranged from a few centimetres to about 10 cm with the maximum displacement rate being recorded in the track zone and in the uppermost part of the accumulation lobe of the landslide borehole systems such as inclinometers and tdr cables have recorded similar rates of movement with the depths of the major active shear surfaces ranging from 48 m to about 10 m from these data it is estimated that the active component of the landslide has a volume of about 50 million m3 in this paper the monitoring data collected so far are presented and discussed in detail to prove that the hazard for the corvara landslide considered as the product of yearly probability of occurrence and magnitude of the phenomenon can be regarded has as medium or high if the velocity or alternatively the volume involved is considered finally it is also concluded that the monitoring results obtained provide a sound basis on which to develop and validate numerical models manage hazard and support the identification of viable passive and active mitigation measures

landslide activity as a geoindicator in italy significance and new perspectives from remote sensing landslide activity responds to rapid environmental changes and represents a relevant geoindicator in mountainous or hilly areas this paper discusses the socio economic relevance of landslide hazard in italy and the problems encountered in establishing relationships between landslide frequency climate and vegetation changes at different time scales landslides blocking a river channel have been carefully taken into account because they are usually characterized by high intensities with regard to the involved masses and movement velocities and their occurrences are often datable via radiocarbon dating this is due to the recovery of organic matter in the landslide dammed lakes for these reasons they can be considered important geoindicators in the wider category of slope failures the marked effects of the anthropogenic activity on slope instability processes in the last 50 years are discussed with reference to two case histories the chianti hills in tuscany and the cinque terre national park in liguria finally two novel techniques of remote sensing are proposed as tools for a systematic monitoring of slope instability at different time and spatial scales both techniques are based on the interferometric synthetic aperture radar sar technology and differ on the type of platform satellite and ground based used to acquire data

integration between ground based and satellite sar data in landslide mapping the san fratello case study abstract the potential use of the integration of psi persistent scatterer interferometry and gb insar ground based synthetic aperture radar interferometry for landslide hazard mitigation was evaluated for mapping and monitoring activities of the san fratello landslide sicily italy intense and exceptional rainfall events are the main factors that triggered several slope movements in the study area which is susceptible to landslides because of its steep slopes and silty clayey sedimentary cover in the last three centuries the town of san fratello was affected by three large landslides developed in different periods the oldest one occurred in 1754 damaging the northeastern sector of the town in 1922 a large landslide completely destroyed a wide area in the western hillside of the town in this paper the attention is focussed on the most recent landslide that occurred on 14 february 2010 in this case the phenomenon produced the failure of a large sector of the eastern hillside causing severe damages to buildings and infrastructures in particular several slow moving rotational and translational slides occurred in the area making it suitable to monitor ground instability through different insar techniques ps insar permanent scatterers sar interferometry techniques using ers 1 ers 2 envisat radarsat 1 and cosmo skymed sar images were applied to analyze ground displacements during pre and post event phases moreover during the post event phase in march 2010 a gb insar system able to acquire data continuously every 14 min was installed collecting ground displacement maps for a period of about three years until march 2013 through the integration of space borne and ground based data sets ground deformation velocity maps were obtained providing a more accurate delimitation of the february 2010 landslide boundary with respect to the carried out traditional geomorphological field survey the integration of gb insar and psi techniques proved to be very effective in landslide mapping in the san fratello test site representing a valid scientific support for local authorities and decision makers during the post emergency management

permanent scatterers for landslide investigations outcomes from the esa slam project within the slam project service for landslide monitoring launched in 2003 by the european space agency esa the permanent scatterers ps technique a multi image interferometric approach coupled with the interpretation of aerial photos and optical satellite images was carried out for landslide investigations the ps analysis was applied at a regional scale as support for landslide inventory mapping and at local scale for the monitoring of single well known slope movements for the integration of the ps measurements within a landslide inventory the arno river basin italy was chosen as test site for the presence of a high number of mass movements to date about 300 areas at high landslide risk and more than 27 000 individual landslides mapped by the institutional authorities about 350 sar images have been interferometrically processed by means of the ps technique with the detection of about 600 000 ps the use of optical images contributed spatial meaning to the point wise information provided by the ps making it easier to identify terrain features related to slope instability and the landslide boundaries here we describe the employed methodology and its impact in the updating of a preexisting landslide inventory 6 8 of the total number of landslides were characterized by ground displacement measurements from the ps 6 1 of already mapped landslides and 0 8 of new unstable areas detected through the ps analysis moreover most of the ps are located in urban areas showing that the proposed methodology is suitable for landslide mapping in areas with a quite high density of urbanization but that over vegetated areas it still suffers from the limitations induced by the current space borne sar missions e g temporal de correlation on the other hand the use of insar for the monitoring of single slow landslides threatening built up areas has provided satisfactory results allowing the measurement of superficial deformations with high accuracy on the landslide sectors characterized by a good radar reflectivity and coherence

paleomagnetic evidence that the central block of salinia california is not a far traveled terrane new paleomagnetic results from late cretaceous 75 85 m y red beds on the central block of salinia indicate that salinia was located within 6 in latitude of its current cratonal north american position during the late cretaceous after correction for neogene san andreas fault transport the red beds formed as alluvial fan overbank deposits with hematite cement deposited directly on salinian granites in the la panza range paleomagnetic analysis shows two components of magnetization in the red beds a low blocking temperature present day overprint residing in goethite and a high blocking temperature 600 component residing in hematite the hematite magnetization is a chemical remanent magnetization which formed soon after deposition during pedogenesis the bedding corrected hematite remanence contains a magnetic polarity stratigraphy with antipodal normal and reversed directions twenty three class i sites 95 20 have an average hematite direction with inclination 54 4 and declination 18 2 95 6 1 after structural correction these paleomagnetic data suggest that salinia resided at about 35 n latitude during the late cretaceous within 6 of its current location adjacent to cratonal north america by contrast a summary of paleomagnetic data from the peninsular ranges terrane and the sur obispo terrane which are currently outboard of salinia shows northward transport of these terranes of 12 to 22 relative to their current locations in north america since the cretaceous the offsets increase systematically away from the craton with the most outboard sur obispo terrane which is composed of accretionary prism and distal forearc material showing the largest degree of northward translation

measuring the in situ deformation of retaining walls by the digital image correlation method in this study the digital image correlation dic method was used to monitor the full field deformation of a retaining wall two retaining walls located in mountainous areas of taiwan were investigated the first fushan slope was characterized by substantial long term deformation and the second bulao slope was located beneath an expressway and was severely damaged by typhoon morakot this paper first describes the preparation procedures for in situ applications of the dic method various environmental factors such as fog rain light direction and spot mark clarity affected measurement precision and consequently produced monitoring images that were unsuitable for further analysis the dic analysis results clearly indicate the deformation pattern of the retaining walls the proposed method is accurate and effective for performing long term monitoring of retaining walls and the results can be used to accurately predict the tendency location and quantity of retaining wall displacement therefore the proposed dic method can be implemented to prevent disasters caused by landslide

remote monitoring of the comba citrin landslide using discontinuous gbinsar campaigns this paper describes the use of the discontinuous ground based interferometric synthetic aperture radar technique gbinsar to monitor the displacement of the comba citrin landslide in the north western italian alps two gbinsar surveys were carried out respectively during the summer and the fall of 2015 separated by a temporal baseline of 63 days for each gbinsar survey which lasted respectively 166 2 h 6 dd 22 h 12 and 238 3 h 9 dd 22 h 18 two sets of 139 and 275 sar images were acquired after the selection of a specific stack of persistent scatterers the sar images of each survey were analyzed separately and in combination with the images of the other survey to detect the possible displacements occurred both in every single survey as well as in the elapsed time between the two different campaigns the displacement maps showed that two different sectors of the monitored slope were affected by millimetres to centimetres movements during the monitoring period the results obtained for the comba citrin landslide show that the discontinuous gbinsar can be reliably adopted to monitor the displacement of landslides moving at an average rate of few centimetres per year

deflation of mount etna monitored by spaceborne radar interferometry ground based measurements of volcano deformation can be used to assess eruptive hazard but require the costly and often hazardous installation and maintenance of an instrument network here we show that spaceborne radar interferometry which has already shown its utility in mapping earthquake related deformation1 can be used to monitor long term volcano deformation two families of synthetic aperture radar images acquired from ascending and descending orbits by the satellite ers 1 and looking at mount etna from opposite sides cover the time period from 17 may 1992 to 24 october 1993 and include the second half of etna s most recent eruption despite artefacts of the interferometric technique we can observe a volcano wide deflation which is an expected consequence of the eruption but which had not previously been appreciated we quantify it using a simple model based on the change of pressure in a sphere located in an elastic half space the modelled deformation increases linearly with time until the end of the eruption our results show that it will be possible to use this technique to detect the inflation of volcanic edifices that usually precedes eruptions

process oriented use of geostatistics to analyse creeping para glacial features complex para glacial systems may show signs of destabilization leading to frequent and potentially hazardous debris flows understanding creeping permafrost displacement over a period of time is therefore crucial for hazard management and risks assessment this paper presents our methodology for estimating creeping permafrost displacement based upon data derived from various survey methods and demonstrates its relevance on the glacier bonnard system in southern switzerland geostatistical processing allowed estimation of the displacement intensity over the area of interest as well as assessment of the interpolation quality although the local measurement network needs to be refined the results largely improve the understanding of the bonnard para glacial system though highlighting the need to locally refine the measurement network in the present case the destabilized front advances at 1 m a and the upstream creeping part at 0 4 m a variance analysis also provide objective thresholds that could be used to distinguish underlying physical processes copyright 2015 john wiley sons ltd

integration of radar interferometry and laser scanning for remote monitoring of an urban site built on a sliding slope the alpine village of lamosano belluno italy located near a wide and active landslide has been seriously threatened by ground instabilities since 1960 in this paper the results obtained by two different remote monitoring techniques synthetic aperature radar interferometry and three dimensional laser scanner imaging planned for lamosano hazard assessment are presented both techniques compare images taken at different times to map and classify changes that occurred on the imaged scenario the radar and laser data are gathered at the same dates with about ten month temporal separation the displacements measured separately by each of the two techniques highlight a similar sliding motion on the lamosano village area providing a good validation to each other and contributing to the definition of the village instability hazard

geochemical constraints on the petrogenesis of the salinian arc central california implications for the origin of intermediate magmas article i nfo magmatic arcs are the primary locations where continental crust is distilled to an intermediate calc alkaline composition the root zones of continental arcs are thought to be the primary sites of magmatic differentiation yet few deeply exhumed arc sections are available for direct study the coast ridge belt of central coastal california provides an exceptional opportunity to directly observe the cumulative effects of melting mixing assimilation and homogenization related to construction of the latest cretaceous california arc we present new major and trace elementchemistry aswellasradiogenicisotopicratiosdeterminedoncoastridgebeltassemblagesrepresentative of 20 to 30 km crustal levels late cretaceous ca 93 to 81 ma gabbro diorite tonalite and granodiorite of the coast ridge belt are calc alkaline some exhibit cumulate characteristics and all show enriched isotopic composi tions sri 0 7061 to 0 7092 and end 1 4 to 5 9 rare earth element patterns in igneous and metaigneous rocks of the coast ridge belt suggest that they are sourced deeper than the 25 km paleodepth of the exposed sec tion but probably not significantly below 40 km underplating of basaltic melts derived from evolved lithospheric mantle provides the most satisfactory mechanism explaining geochemical and field evidence for partial melting and assimilation of metasedimentary framework rocks to yield gabbroic to dioritic magmas followed soon there afterby remelting to produce more silicic magmas we suggest that basaltic underplating provided a source of heat to the base of the salinian crust leading to thermal weakening and downward flow of melt fertile intra arc supracrustal assemblages thereby igniting the magmatic pulse that formed the salinian arc

mapping small elevation changes over large areas differential radar interferometry a technique that uses synthetic aperture radar sar images to measure very small 1 cm or less surface motions with good resolution 10 m over large swaths 50 km is presented along with experimental results the method could be used for accurate measurements of many geophysical phenomena including swelling and buckling in fault zones residual displacements from seismic events and prevolcanic swelling the method is based on sar interferometry where two images are made of a scene by simultaneously flying two physically separated antennas then the phases of corresponding pixels are differenced and altitude formation is deduced from some simple computation and image rectification it is also possible to use one antenna flown twice over the same scene then if the second flight exactly duplicates the track of the first an interesting possibility occurs there would be no phase changes between the images at all unless there was a physical change in the scene such as ground swelling that would alter the distance from some resolution element to the antenna since the phase changes all occur at the short carrier wavelength the basic limitation on sensitivity is only the phase noise in the system when the two imaging passes are made from flight tracks that are separated which is the case with the seasat images used here it is no longer possible to distinguish surface changes from the parallax caused by topography however with some additional computation a third image made at some other baseline may be used to remove the topography and leave only the surface changes this method was applied using seasat data to an imaging site in imperial valley california where motion effects were observed that were ascribed to the expansion of water absorbing clays phase change images of this area are shown along with associated ground truth about the presence of water problems with the technique are explored along with a discussion of future experimental possibilities on upcoming sar missions like earth observing system eos earth resources satellite ers 1 sir c and the venus imaging radar magellan

the gravitational landscape of montespertoli valdelsa basin tuscany italy state of activity and characteristics of complex landslides abstract the town of montespertoli florence province is located on a nw se ridge that separates the valdelsa river basin to the west from the val di pesa basin to the east the bedrock is characterised by alternations of alluvial transitional and marine deposits with a maximum gradient of 5 the slopes surrounding the town are affected by a series of rock slides flows and complex landslides usually roto translational slides that evolve into rock flows the headward evolution of the landslide escarpments threatens the stability of several buildings and streets the conditions leading to the activation of these gravitational movements are mainly based on the lithological setting and downcutting of river valleys in addition recent inappropriate water management plays an important role locally the aim of this study is to illustrate the importance of gravitational phenomena in the modelling of areas with this type of structural setting which is very common in many italian regions and to identify the geometry and state of activity of gravitational movements to verify the activity of the movements in recent decades multitemporal analysis was carried out using orthophotos of four different periods 1954 1988 1996 and 2013 based on the results a classification of the degree of activity of the landslides was introduced which can be applied at the regional scale by the regional authority several researchers proposed to utilise synthetic aperture radar sar technology the use of aerial photos is of advantage because these photos are easily available at a very low price as needed by professional geologists

on the derivation of coseismic displacement fields using differential radar interferometry the landers earthquake we present a map of the coseismic displacement field resulting from the landers california june 28 1992 earthquake derived using data acquired from an orbiting high resolution radar system we achieve results more accurate than previous space studies and similar in accuracy to those obtained by conventional field survey techniques data from the ers 1 synthetic aperture radar instrument acquired in april july and august 1992 are used to generate a high resolution wide area map of the displacements the data represent the motion in the direction of the radar line of sight to centimeter level precision of each 30 m resolution element in a 113 km by 90 km image our coseismic displacement contour map gives a lobed pattern consistent with theoretical models of the displacement field from the earthquake fine structure observed as displacement tiling in regions several kilometers from the fault appears to be the result of local surface fracturing comparison of these data with global positioning system and electronic distance measurement survey data yield a correlation of 0 96 thus the radar measurements are a means to extend the point measurements acquired by traditional techniques to an area map format the technique we use is 1 more automatic 2 more precise and 3 better validated than previous similar applications of differential radar interferometry since we require only remotely sensed satellite data with no additional requirements for ancillary information the technique is well suited for global seismic monitoring and analysis

internal structure and deformation of an unstable crystalline rock mass above randa switzerland part i internal structure from integrated geological and geophysical investigations 6m 3 of material occurred in fractured gneissic rock whose principal foliation faults and fracture zones dip into the slope above the scarp of the second rockslide the mountain continues to move at rates of up to 2 cm year in an attempt to understand failure mechanisms in fractured crystalline rock masses we have carried out a comprehensive multidisciplinary study that included detailed geological mapping borehole logging and imaging and surface and borehole geophysical surveys an integrated interpretation of the resultant data has revealed the presence of three prominent fault and fracture zone sets that define the internal structure of the rock mass some faults and fracture zones could be traced up to 85 m into the subsurface using borehole radar reflection methods the dips of the faults and fracture zones estimated from surface mapping matched those from radar reflection and borehole televiewer surveys no evidence was found for significant faults or persistent weakness planes that paralleled the 1991 rockslide failure surfaces instead the new observations were consistent with dominant failure mechanisms that involve the progressive development of major shear and brittle fracturezones and the eventual destruction of intact rock bridges immediately prior to catastrophic collapse this integrated study provides the first reliable model of the 3 d fault structure associated with and contributing to a large rock slope instability in a brittle crystalline rock mass

thermobarometric constraints on the depth of exposure and conditions of plutonism and metamorphism at deep levels of the sierra nevada batholith tehachapi mountains california we present thermodynamic estimates of pressures temperatures and volatile activities in variably deformed gabbroic to granitic cretaceous 115 100 ma batholithic and framework rocks of the tehachapi mountains southernmost sierra nevada california al contents of hornblende in granitoids imply igneous emplacement at 8 kbar in the southernmost tehachapi mountains with lower pressures 3 7 kbar to the north metamorphic pressures and temperatures for garnet bearing paragneisses and metaigneous rocks were estimated on the basis of garnet hornblende plagioclase quartz and garnet biotite plagioclase quartz thermobarometers disparate results for the metaigneous rocks from the latter system point to the difficulty of applying pelite based thermobarometers to rocks of contrasting composition and mineralogy preferred pressures cluster at 7 1 9 4 and 3 6 4 3 kbar incomplete knowledge of reaction histories however limits our interpretation of the lower pressures because they are minimum estimates the 4 kbar samples are all from a small area and if our interpretation is correct they imply a local more shallow event superimposed on crust once residing at deeper structural levels garnet hornblende and garnet biotite temperatures are less coherent likely owing to retrograde fe mg exchange and range from 570 to 790 c the majority of the rocks are igneous and affected by recrystallization and metamorphism during subsolidus cooling they are not granulites country rock paragneisses are typically migmatized at peak metamorphic conditions near that of the wet granite solidus 690 c veinlike paragenesis of garnet in the metaigneous rocks suggests formation related to the presence of a fluid phase thermodynamic estimates of volatile activities in these garnet bearing assemblages suggest variable mostly co 2 rich fluid compositions in the absence of any pervasive fluid flux the igneous rocks of the tehachapi mountains were thus intruded at depths of 30 km making them the deepest known exposed components of the cretaceous sierra nevada batholith metamorphism occurred at these great depths and perhaps locally after 15 km of uplift before 87 ma implying an uplift rate of 1 2 mm yr a minimum uplift rate is 0 6 mm yr this original uplift and possible subsequent uplift events may have been related to underthrusting of a block of rand schist from what is now the southeast with concomitant widespread ductile deformation the deduced pressure temperature and uplift history is similar to those of high pressure high temperature cretaceous batholithic rocks in salinia and the san gabriel mountains but direct correlation is not wan anted when compared with higher level intrusive rocks from analogous portions of the sierra nevada batholith to the north the tehachapi rocks reveal a deep batholith that is more heterogeneous and somewhat more mafic on average but displaying a similar level of isotopic hybridization involving mantle and crustal sources the batholith is quartz rich at these levels suggestive of a weak ductile middle crust susceptible to prolonged deformation and possible delamination

ground motion phenomena in caltanissetta italy investigated by insar and geological data integration abstract urban areas are frequently affected by ground instabilities of various origins the location of urban zones affected by ground instability phenomena is crucially important for hazard mitigation policies satellite based interferometric synthetic aperture radar insar has demonstrated its remarkable capability to detect and quantify ground and building motion in urban areas especially since the development of advanced differential interferometric sar techniques a dinsar in fact the high density of reflectors like buildings and infrastructures in urban areas improves the quality of the insar signal allowing sub centimetric displacements to be reliably detected the a dinsar techniques allow urban zones affected by ground deformation to be located and mapped but clearly they are not able to point out the causes of the instability phenomena these can only be highlighted by an integrated analysis of multidisciplinary data like geological geotechnical sar interferometric and historical data the overlay of these data which is possible within a geographic information system gis is a useful tool to identify ground motion phenomena affecting urban zones in this study we apply this kind of approach to caltanissetta a provincial capital in sicily italy where local damage has been detected the reconstruction of the local near surface geology shows the presence of zones affected by local natural hazard factors essentially due to the local presence of soils with poor mechanical properties or swelling soils high topographic gradients and steep slopes on loose soils processing 17 asar envisat sar images covering the time interval october 2002 december 2005 by means of an a dinsar procedure the caltanissetta deformation map has been realized it shows that most of the city is stable with the exception of three zones situated in the northwestern northeastern and southern parts of the city respectively two of them characterized by high topographic gradients and steep slopes on sandy soils are affected by subsidence ground motion an uplift motion is recognized in the other zone characterized by the local presence of expansible clays geotechnical swelling tests carried out on them have shown a swelling behavior on site surveys have highlighted the presence of damage in the zones affected by ground motion

two examples of the use of sar interferometry on displacement fields of small spatial extent interferometric combination of pairs of sar images acquired by the european ers 1 satellite maps deformation fields associated with two phenomena both of small spatial extension and located in se france the one is rapid terrain deformation caused by a landslide near the city of saint etienne de tinee and the other is slower subsidence caused by underground coal mining near gardanne unlike interferometric measurement of wide field deformation atmospheric propagation heterogeneity is not an accuracy limiting factor although the radar data confirm prior knowledge concerning the landslide such an application of sar interferometry appears difficult under normal conditions of observation using current spaceborne radar systems the study of soil subsidence however can be generalized and improves prior knowledge of the displacement field which has here been modeled assuming elastic deformation in a half space from several sources the two examples help to understand the limits of the interferometric technique

the role of mantle delamination in widespread late cretaceous extension and magmatism in the cordilleran orogen western united states extension during plate convergence and mountain building is widely recognized yet the causes of synconvergent extension remain controversial here we propose that delamination of lithospheric mantle aided by decoupling of the crust from the mantle via a reduction in the viscosity of the lower crust through heating incursion of fl uids and partial melting explains many enigmatic yet prevalent aspects of the metamorphic magmatic and kinematic history of the sevier laramide orogen of the western united states during the late cretaceous extension heating anatexis magmatism and perhaps rock uplift were widespread during a restricted time interval in the late cretaceous 75 67 ma along the axis of maximum crustal thickening within the mojave sector of the sevier orogen and to a lesser extent within the interior of the idaho utah wyoming sector to the north similar processes may have been active in the peninsular range sierran western mojave and salinian segments of the mesozoic cordilleran arc these processes are viewed as predictable consequences of the thermal rheological and dynamic state of the overlying crust following delamination of mantle lithosphere beneath isostatically compensated mountain belts the proposed delamination would have occurred immediately prior to eastward propagation of lowangle subduction of the farallon plate during the inception of the laramide orogeny following delamination extension and anatexis of the north american crust were aided locally by egress of slab derived fl uids from the low angle farallon slab we suggest that lithospheric delamination may have aided in the shallowing of the slab to achieve lowangle subduction geometry delamination has been proposed to be common in areas of thickened continental lithosphere in the terminal phase or late in orogenesis the late cretaceous delamination event proposed here for the sevier laramide orogen occurred during protracted plate convergence and was synchronous with and followed by continued shortening in the external part of the orogen

in situ monitoring platform and preliminary analysis of monitoring data of majiagou landslide with stabilizing piles abstract reservoir landslide evolution is a complex multi fields dynamic process which involves the interaction of the seepage field stress field displacement field and temperature field after installing the stabilizing structure into landslide the landslide and stabilizing structure will establish the landslide stabilization system and lead to a more complex multi fields evolution process under the reservoir operation to study this complex problem this paper designs and establishes a comprehensive in situ multi fields information monitoring platform which has been installed on majiagou landslide in three gorges reservoir area the multi fields information monitoring platform has four components the landslide stabilization system the in situ multi field monitoring system the data transmission and receiving system and the database management system the landslide stabilization system includes majiagou landslide and two experimental reinforced concrete piles the in situ monitoring system consists of landslide surface deformation monitoring system experimental piles monitoring system and boreholes monitoring system the landslide surface deformation monitoring system includes gps stations and fiber lines the experimental pile monitoring system consists of earth pressure cells around piles stress and strain gauges on steel bars and strain and temperature fiber sensors in piles the borehole monitoring system includes boreholes with inclinometers water pressure and water level gauges fiber sensors therefore the in situ monitoring system can monitor the seepage stress displacement and temperature fields in the landslide as well as the force and deformation in the experimental piles currently the data transmission and management system is under construction and will be finished soon current monitoring results show that the landslide moves along three slip surfaces and the deformation of the experimental piles is influenced by reservoir operation this platform can provide multi fields data for scholars to study the evolution of landslide stabilization system

tectonic and magmatic development of the salinian coast ridge belt california 1 we present new field structural petrographic and geochronologic data on a rare midcrustal 25 km exposure of a cordilleran arc the coast ridge belt located in the santa lucia mountains of central california the study area is composed primarily of a deformed suite of upper amphibolite to granulite facies rocks the sur series which is dominated by metaigneous tonalites diorites and gabbros with subordinate metasedimentary quartzite and marble inherited zircons in magmatic rocks suggest that the provenance of framework rocks is drawn heavily from miogeoclinal formations and that sedimentation occurred in the late paleozoic or later minor magmatism in the coast ridge belt began in the early or middle cretaceous but magmatic activity was most intense during a short period time from 93 to 81 ma based on u pb zircon ages of a felsic gneiss and two less deformed diorites the time period 93 81 ma also brackets a period of extensive thickening and high temperature ductile deformation while a thrusting cause for ductile deformation cannot be ruled out we favor the hypothesis that the exposed rocks correspond to a zone of return flow of supracrustal rocks locally displaced by granitoid plutons in the shallower crust magmatism ended throughout salinia between81and76ma coincidentwiththeattainmentof peak pressure and temperature conditions of 0 75 gpa and 800 c exhumation followed immediately bringing the coast ridge belt to the surface within 8 my at a rate of at least 2 3 mm yr exhumation was coincident with an episode of extensional collapse that has been documented elsewhere in the southern california arc during the early laramide orogeny and that may be related to underthrusting of the forearc at that time index terms 8102 tectonophysics continental contractional orogenic belts 8035 structural geology pluton emplacement 3640 mineralogy and petrology igneous petrology 8030 structural geology microstructures 8124 tectonophysics earth s interior composition and state 1212

topographic mapping from interferometric synthetic aperture radar observations interferometric synthetic aperture radar observations provide a means for obtaining high resolution topographic terrain maps from data acquired simultaneously at two slightly displaced antennas calculation of the three dimensional coordinates of all the points in a radar image can be made from the combination of along track slant range and interferometer fringe measurements thus the result compensates for the layover exhibited by conventional radar maps and removes the false targets generated by multiple signal paths to a given object in the scene we have derived a topographic map of a portion of the san francisco bay area utilizing data that were recorded by a radar system mounted on a nasa cv990 aircraft and processed by a general purpose digital computer this map displays the height above sea level of a region approximately 11 km by 10 km in size sampled on an 11 m pixel grid uncertainties in the estimated height result from imprecise knowledge of the observational geometry radar bandwidth limitations and finite signal to noise ratios for our system each factor contributed approximately 3 4 m to a relative rms error of about 6 m additional global errors of the order of 10 m can result from inaccurate monitoring of aircraft attitude the statistical variation of the height measurements from the ocean portion of the map which we can presume to be quite flat is 2 10 m rms which is consistent with the theoretical estimate comparison of our results with u s geological survey contour maps indicates a high degree of correlation between the two sets of altitude data

a low cost landslide displacement activity assessment from time lapse photogrammetry and rainfall data application to the tessina landslide site abstract acquiring useful and reliable displacement data from a complex landslide site is often a problem because of large localized and scattered erosive processes and deformations the inaccessibility of the site the high cost of instrumentation and maintenance however these data are of fundamental importance not only to hazard assessments but also to understanding the processes at the basis of slope evolution in this framework time lapse photogrammetry can represent a good compromise the low accuracy is compensated for by the wide ranging and dense spatial displacement information that can be obtained with inexpensive equipment nevertheless when large displacement monitoring data sets become available the problem becomes the choice of the most suitable statistical model to describe the probability of movement and adequately simplify the complexity of a scattered intermittent and spatially inhomogeneous displacement field in this paper an automated displacement detection method which is based on the absolute image differences and digital correlations from a sequence of photos was developed and applied to a photographic survey activity at the head of the tessina landslide northeastern italy the method allowed us to simplify and binarize the displacement field and to recognize the intermittent activity and the peculiar behaviours of different parts of the landslide which were identified and classified by combining geomorphological and geological information moreover for the first time sliding correlations between these areas were quantitatively estimated using time series based binary logistic regression and the definition of a probability based directed graph of displacement occurrence that connected the source zones to the lower depletion basin and the main collector channel using rainfall data event based logistic and poisson regression models were applied to the upper zones of the landslide to estimate the probability of movement of each scarp and the persistence of the displacement as a result of certain rainfall events the results of these statistical analyses highlighted the capability of this approach to quantitatively evaluate the pattern of displacement occurrences and to assess the evolution of a landslide site to gain insight into geomorphological processes

speculative reconstruction of the mojave snow lake fault implications for paleozoic and mesozoic orogenesis in the western united states available evidence suggests that the mojave snow lake fault a major early cretaceous dextral fault with up to 400 km displacement formerly existed in what is now the axial part of the sierra nevada batholith regional relations suggest that the fault formerly continued in western nevada the mojave desert and in rocks now exposed in the salinian block restoration of 400 km of early cretaceous dextral displacement on the mojave snow lake fault leads to speculative but testable reconstructions of mesozoic and paleozoic tectonic features of california and nevada insights derived from these reconstructions include the following 1 two regionally extensive jurassic thrust belts of opposed vergence appear to have intersected in the northern sierra nevada the eastern east vergent thrust belt which includes the fencemaker and liming thrusts in western nevada and several east vergent thrusts in the northern sierra may be a contractional belt along which an early jurassic interarc or marginal basin was closed in middle to late jurassic time the western west vergent thrust belt is part of the classic nevadan orogen of the western klamath mountains and the western sierra metamorphic belt in which collisions and or thrusting of various island arc terranes occurred during middle and late jurassic time 2 the early mesozoic continental arc included paired belts of triassic jurassic blueschist and melange and igneous rocks including late triassic and younger plutons and volcanic rocks this conclusion is not new but the reconstruction provides a slightly different geometry than previously thought 3 sonomia the late paleozoic island arc terrane of the western u s may have formed a relatively narrow belt extending from northwestern nevada to the latitude of the western mojave desert the geologic development of the paleozoic basement complex of sonomia was very different from that of the cordilleran miogeocline in death valley and the mojave desert requiring that a continuation of the sonoma suture belt or golconda thrust must have extended southward through the sierra nevada batholith to the mojave region 4 a heterogeneous belt of permian to triassic or triassic deformation in the mojave and eastern sierra nevada together with the golconda allochthon in nevada may represent the protracted response to the collision of sonomia with the western margin of north america the contractional deformation continued during the evolution of the early mesozoic continental arc 5 several predictions can be made about the nature of concealed basement within the sierra nevada batholith and within western nevada the reconstruction suggests that elements of the antler and sonoma orogenic belts should underlie areas of the batholith and western nevada as a result of northward displacement along the mojave snow lake fault from the western mojave and southern sierra nevada

monitoring very slow slope movements by means of sar interferometry a case study from a mass waste above a reservoir in the otztal alps austria the application of radar interferometry to detect slope movements on the order of millimeters to centimeters per year is demonstrated the deformation field of a slope above a hydropower reservoir in the austrian alps was derived from sar interferometric pairs of the satellites ers 1 and ers 2 acquired between july 1992 and august 1998 above the treeline it was possible to map the motion from interferograms covering time spans up to three years whereas ground based geodetic measurements focussed on the movements of the lower slope section the interferometric analysis shows that the mass wasting processes affect the entire slope of 1000 m vertical extent significant interannual differences of the displacement rates became apparent which were found to be related to the pattern of summer rainfall

synergic use of satellite and ground based remote sensing methods for monitoring the san leo rock cliff northern italy abstract the historic town of san leo emilia romagna region northern italy is located on top of an isolated rock massif above the marecchia river valley hillside on february 27th 2014 a northeastern sector of the massif collapsed minor structural damages were reported in the town and a few buildings were evacuated as a precautionary measure although no fatalities occurred and the san leo cultural heritage suffered no damage minor rock fall events kept taking place on the newly formed rock wall worsening this hazardous situation in this framework a monitoring system based on remote sensing techniques such as radar interferometry both spaceborne and ground based and terrestrial laser scanning was planned in order to monitor the ground deformation of the investigated area and to evaluate the residual risk in this paper the main outlines of a 1 year monitoring activity are described including a pre event analysis of possible landslide precursors and a post event analysis of the displacements of both the collapse affected rock wall sector and the rock fall deposits

landslides in sado island of japan part i case studies monitoring techniques and environmental considerations abstract a sufficient knowledge on the kinematics and development of landslides helps to adopt proper measures that can be used to protect slopes and the environment in general this can be achieved by adequate monitoring programs this paper presents the findings of intensive monitoring activities carried out on shiidomari and katanoo landslides found in sado island of japan more than one year of observation of the two landslides allowed defining some peculiar futures of their kinematics and style of development the problem of slope instability in the two areas is generally accredited to various factors but both landslides were triggered by heavy rainfalls and snowmelt because of the outline of the area and the presence of relict topographic features the shiidomari landslide is considered to be a large scale reactivation of old slope failures the katanoo landslide is however a first time case geophysical investigations and drilling activities in shiidomari indicated the presence of two slip planes the deepest 80 100 m of these is controlled by existing lineaments monitoring data suggests that the body of the landslide has subsided as much as 1 16 m just below the main scarp but a centimeter in the central region the toe sector also experienced a significant amount of subsidence but this was counter balanced by an uplift on the opposite side of the landslide hence the landslide seems not any more active along the deepest slip surface although it may extend upward and define a series of shallow shear planes around the crown in the case of katanoo the landform characteristics differential weathering the road cut and groundwater fluctuations appeared to contribute much to determine the exact location of the landslide extensional cracks that preceded the landslide can be related to heavy rainfalls and the cold and warm cycles thereafter subsurface investigations and monitoring works indicated that the landslide has two slide blocks with different slip planes during the observation period the upper part of the landslide responded more effectively to rainfall and snowmelt than the middle and lower sections the corresponding movements however appeared to settle about three months after failure there were also little strain transmissions in boreholes and no significant change in the characteristics of the landslide the kinematics of deformation of many of the slopes in sado island resembles that of shiidomari landslide but mass movements along highways and mountain roads are usually similar to katanoo landslides of the type like shiidomari may not show sudden and drastic failures but are usually long lasting and can reactivate repeatedly along new shallow shear planes monitoring works and long term supervisions in these types of landslides are useful to identify impending failures and take the right measures before they brought about large scale destruction to the environment

characterization of landslide ground surface kinematics from terrestrial laser scanning and strain field computation assessment and mitigation of the risk induced by landslide activation need an appropriate phenomenon investigation to obtain useful information about the failure processes the first step is the complete kinematics characterization of the landslide ground surface by evaluating the involved displacement and deformation patterns a dense displacement field can be obtained from comparison of a series of multi temporal observations performed by means of terrestrial laser scanning subsequently the strain field can be computed from displacement vectors in this paper a modified least square technique is employed to compute the strain on the nodes of a regular grid 2d approach or on the points of a digital terrain model 3d approach such a computation takes into account the displacements their spatial distribution as well as the measurement and modelling errors a scale factor is introduced in order to emphasize the contributions of the experimental points on the basis of their distance from each computation point and to recognize possible scale depending behaviours this method has been implemented in matlab and applied on two landslides located in the northeastern italian alps lamosano and perarolo di cadore the experiments show that different kinematics can be recognized and the presence and influence of eventual discontinuities can be revealed

landslide monitoring by using ground based sar interferometry an example of application to the tessina landslide in italy abstract an innovative technique based on radar interferometry and implemented using ground based instrumentation has been applied for monitoring the tessina landslide italy belluno the technique has allowed us to derive multitemporal surface deformation maps of the entire depletion zone of the landslide with a high spatial resolution and accuracy the portable device used in this application is known as linear sar lisa and it is able to provide measurements at 17 ghz with a synthetic aperture of up to 2 8 m the results have been validated by comparing the recorded pixel displacements with independent measurements carried out by a motorized theodolite and electronic distance meter edm on two benchmarks

observation and modelling of the saint etienne de tinee landslide using sar interferometry abstract six different interferograms of the la clapiere landslide were derived from ers 1 sar images during the period aug 20 sept 4 1991 the coherence of the associated images is shown to remain significant over most of the surface of the landslide during the two weeks of the survey the interferograms are remarkably similar and indicate steady state displacements over at least 12 days the displacement field derived from the interferograms is shown to be characterized by a non uniform displacement gradient from top to bottom and reveals a significantly faster motion of the western part of the landslide the amplitude of the motion deduced from interferometry is shown to be in good agreement with ground measurements finally sar interferometry is shown to be able to evidence small scale instabilities which may not be observed with discrete ground measurements

ground based radar interferometry for landslides monitoring atmospheric and instrumental decorrelation sources on experimental data the application of ground based radar interferometry for landslide monitoring is analyzed a case study based on an experimental campaign carried out in italy during 2002 is discussed interferometric data obtained from coherent synthetic aperture radar sar images acquired by means of c band ground based equipment are analyzed the campaign was aimed at retrieving potential terrain movements of a small landslide observed hundreds of meters away critical aspects related to spatial and temporal decorrelation are discussed the use of optical photogrammetry as a technique for evaluating mechanical stability and correcting geometric distortion is presented results also confirmed that the application of ground based radar interferometry can be attractive and effective if the acquired sar images maintain an adequate coherence on different dates

using global positioning system techniques in landslide monitoring the precise determination of point coordinates with conventional global positioning system gps techniques often required observation times of one to several hours in the last few years new gps methods have been developed among them the fast static and real time kinematic with higher productivity and good theoretical precision the main objective of this paper is to ascertain the performance of these methods in landslide monitoring practice we present first of all the basic principles of the gps the equipment and working procedures we discuss afterwards the applicability of the gps to the monitoring of landslide surface displacements compared with the classical surveying methods the gps allows a larger coverage and productivity with similar accuracy furthermore it can work in all kinds of weather conditions and a direct line of sight between stations is not required finally we present an example of the performance of the gps equipment in the landslide of vallcebre eastern pyrenees spain this landslide has been periodically monitored since 1987 with terrestrial photogrammetry and geodetic measurements theodolite electronic distance metres edm the movement extends over an area of 0 8 km2 and has experienced displacements as large as 1 6 m during the period 1996 1997 14 campaigns over a period of 26 months using both static and kinematic gps methods have been carried out the gps measurements have been compared with the results obtained with the edm inclinometers and wire extensometers and checked against fixed stable points the precision achieved with the gps measurements is 12 to 16 mm in the horizontal plane and 18 to 24 mm in elevation 2000 elsevier science b v all rights reserved

ground based sar interferometry for terrain mapping theory and sensitivity analysis this short communication studies the problem of terrain mapping by means of the ground based synthetic aperture radar gb sar interferometry technique a phase to height relationship tailored for the gb sar interferometric configuration is introduced and verified by a simulated analysis a sensitivity study is carried out aiming to optimize the use of a gb sar system for the terrain mapping and to derive the precision of this technique

integrating radar and laser based remote sensing techniques for monitoring structural deformation of archaeological monuments ground based synthetic aperture radar interferometry gbinsar and terrestrial laser scanning tls were purposely integrated to obtain 3d interferometric radar point clouds to facilitate the spatial interpretation of displacements affecting archaeological monuments the paper describes the procedure to implement this integrated approach in the real world situations of surveillance of archaeological and built heritage targeted tests were carried out on the case study of the domus tiberiana sited along the northern side of the palatino hill in the central archaeological area of rome italy and displacements of the monument were monitored over almost one year of acquisition the gbinsar tls integration provided updated information about the condition of the archaeological structures in relation to their history of instability mechanisms and did not highlighted a general worsening for the stability of the entire monument point wise and prompt detection of displacement anomalies and or sudden changes in displacement trends proved the suitability of the method to support early warning procedures also to evaluate effects on the masonry due to human activities