modeling ground displacement above reservoirs undergoing fluid withdrawal injection based on an ellipsoidal inhomogeneity model abstract we propose a procedure to efficiently monitor the geomechanical behavior of underground porous reservoirs undergoing fluid withdrawal injection we apply the inhomogeneity problem and invert geodetic data on subsidence uplift to calibrate and specify parameters used for geomechanical models based on pressure changes we first calculate the poroelastic strain of the reservoirs then we test it assuming uniaxial deformation on a three dimensional ellipsoidal inhomogeneity with different semi axes in a full space isotropic elastic domain and finally we apply a simple half space approximation to account for the tractions free ground surface despite its simplicity and the initial full space approximation the semi analytical model derived in this study replicates well poroelastic strains inferred by geodetic data or obtained with other analytical and numerical techniques our model is a good approximation for predicting the profile of surface deformation i e geodetic strain and once calibrated its magnitude

geodetic imaging reservoir monitoring using satellite interferometry summary fluid fluxes within subsurface reservoirs give rise to surface displacements particularly over periods of a year or more observations of such deformation provide a powerful tool for mapping fluid migration within the earth providing new insights into reservoir dynamics in this paper we use interferometric synthetic aperture radar insar range changes to infer subsurface fluid volume strain at the coso geothermal field furthermore we conduct a complete model assessment using an iterative approach to compute model parameter resolution and covariance matrices the method is a generalization of a lanczos based technique which allows us to include fairly general regularization such as roughness penalties we find that we can resolve quite detailed lateral variations in volume strain both within the reservoir depth range 0 4 2 5 km and below the geothermal production zone 2 5 5 0 km the fractional volume change in all three layers of the model exceeds the estimated model parameter uncertainty by a factor of two or more in the reservoir depth interval 0 4 2 5 km the predominant volume change is associated with northerly and westerly oriented faults and their intersections however below the geothermal production zone proper the depth range 2 5 5 0 km there is the suggestion that both north and northeast trending faults may act as conduits for fluid flow

reservoir monitoring and characterization using satellite geodetic data interferometric synthetic aperture radar observations from the krechba field algeria deformation in the material overlying an active reservoir is used to monitor pressure change at depth a sequence of 11 field estimates allows us to construct a measure of diffusive traveltime throughout a reservoir the dense distribution of traveltime values means that we can construct an exactly linear inverse problem for reservoir flow properties application to interferometric synthetic aperture radar insar data gathered over a carbon dioxide c o2 injection site in algeria reveals pressure propagation along two northwest trending corridors an inversion of the traveltimes indicates the existence of two northwest trending high permeability zones the high permeability features trend in the same direction as the regional fault and fracture zones model parameter resolution estimates indicate the features are well resolved

comparison of the quaternary travertine sites in the denizli extensional basin based on their depositional and geochemical data abstract in the denizli basin turkey located in the western anatolian extensional province travertine and tufa deposition has been an ongoing process for at least 600 000 years travertine bodies which are 30 to 75 m thick and each covers areas of 1 to 34 km2 are up to 1 km3 in volume today spring waters in this area have temperatures of 19 to 57 c are of the ca mg hco3 so4 type in the pamukkale kelkaya and pinarbasi areas and the ca mg so4 hco3 type at cukurbag thermal waters along the northern margin of the basin are generally hotter than those in the east southeast and south the 18o and d values of the spring waters indicate a meteoric origin the average temperatures of the hydrothermal systems in the denizli basin appear to have decreased from pleistocene to holocene travertine which formed from the hotter water is more widespread than the tufa that formed in the cooler spring waters deposition of the travertine which formed largely on slopes in depressions and along fissure ridges mostly on northern basin margins was controlled by the interplay between various intrinsic and extrinsic parameters the travertines are formed largely of calcite with only minor amounts of aragonite in some of the vertically banded crystalline crust raft and pisoid travertines found in some of the northern sites the aragonitic samples rich in sr are typically found around the spring orifices and along the central axis of the fissure ridges the stable isotope values of the travertine found in the northwest and southeast parts of the basin are different the 13c values of the northern travertine deposits are more positive 3 7 to 11 7 vpbd than those found in the south southeast areas 4 to 5 8 vpdb in contrast the travertine and tufa in the southeastern areas have higher 18o values 15 2 to 7 8 vpdb than those of the northern areas 16 6 to 4 8 vpdb available evidence indicates that spring activity and associated travertine precipitation in the denizli basin were controlled largely by tectonic activity rather than by climatic conditions

monitoring of fluid injection and soil consolidation using surface tilt measurements temporal variations of surface tilt may be used for the noninvasive monitoring of subsurface volume change such volume changes may accompany settlement near structures the response due to fluid injection or withdrawal and excavation related activity we outline a methodology for using tilt data to estimate volume changes within poroelastic media the expressions relating subsurface volume change and surface tilt are simple and compact offering the possibility of real time monitoring the inversion of actual tilt data from a site near raymond calif generates images of fluid withdrawal from a complex fracture zone about 30 m below the surface volume changes are confined to an elongated north south zone in agreement with independent well test data we have also applied the methodology for the inversion of surface tilt to data from a grout injection experiment in los banos the technique enables us to monitor grout migration through a porous gravel

surface deformation associated with a dipping hydrofracture crustal deformation associated with hydrofracture is modeled by a dipping rectangular dislocation beneath the surface of an elastic half space the burger s vector is taken normal to the rectangular surface analytical expressions for vertical displacements are obtained from integration of volterra s equation by using mindlin s point force solutions for the elastic halfspace in the limits of 0 and 90 dip the results agree with those obtained by maruyama 1964 for poisson s ratio 0 25 expressions for arbitrary poisson s ratio are given for elongate dislocations the displacement field agrees with curves given by pollard and holzhausen 1979 for two dimensional near surface fractures at various dips at dip 0 a deep square dislocation gives displacements indistinguishable from those of sun s 1969 model of a horizontal penny shaped crack beneath the surface of an elastic half space modifying his result for shallow depths shows that they correspond to a dislocation of semi elliptical cross section with the surface displacement field asymptotically approaching a semi elliptical shape as depth decreases to zero similarly the surface displacement field of the square dislocation approaches that of its rectangular cross section nonlinear inversion of surface tilt fields associated with hydrofracture of deep boreholes gives estimates of fracture geometry position and orientation along with their uncertainties two examples are presented one of a near horizontal and one of a near vertical fracture

inversion for sources of crustal deformation and gravity change at the yellowstone caldera the 3100 km2 yellowstone caldera yellowstone national park was formed in the latest of three explosive eruptions of rhyolites and ash flow tuffs totalling 3700 km3 at 2 1 2 and 0 6 m y before present its youthful volcanic history widespread hydrothermal activity intense seismicity and extremely high heat flow in excess of 30 times the continental average marks the yellowstone volcanic system as a giant caldera at unrest orthometric height increases of the caldera of up to 76 cm measured from precise leveling surveys from 1923 to 1975 1977 were inverted to determine volume expansion source models for the caldera wide deformation for the 1923 to 1977 uplift episode two regions of expansion were found 1 in the northern part of the caldera near the sour creek resurgent dome of 0 37 km3 and 2 in the southern part of the caldera near the mallard lake resurgent dome of 0 41 km3 both bodies occur in the upper crust from near surface depths to 6 0 km but the largest volume expansions were found in the 3 0 6 0 tan depth range the southern caldera source volume near the mallard lake dome may extend down to 9 0 km the data are however unable to resolve if these two resurgent domes separated laterally by 40 km are connected prom 1976 to 1987 nearly simultaneous measurements of elevation and gravity changes were made on a profile across the northern caldera during a period of net uplift models of the temporal gravity variation infer that the volume increase for the northern caldera source must lie above 9 0 km and involved a density perturbation greater than 0 002 g cm3 the modeled volumetric sources are in the same general locations as bodies of low p wave velocities high seismic attenuation and large negative bouguer gravity anomalies in view of the intense quaternary volcanism the anomalously high heat flow and the correlation of the source volumes with the regional geophysical anomalies it is likely that the modeled volumetric increases were caused by migration of magmas and or the introduction of large volumes of hydrothermal fluids into the upper crust

estimation of flow properties using surface deformation and head data a trajectory based approach 1 a trajectory based algorithm provides an efficient and robust means to infer flow properties from surface deformation and head data the algorithm is based upon the concept of an arrival time of a drawdown front which is defined as the time corresponding to the maximum slope of the drawdown curve the technique involves three steps the inference of head changes as a function of position and time the use of the estimated head changes to define arrival times and the inversion of the arrival times for flow properties trajectories computed from the output of a numerical simulator are used to relate the drawdown arrival times to flow properties the inversion algorithm is iterative requiring one reservoir simulation for each iteration the method is applied to data from a set of 14 tiltmeters located at the raymond quarry field site in california using the technique i am able to image a high conductivity channel which extends to the south of the pumping well the presence of this permeable pathway is supported by an analysis of earlier cross well transient pressure test data

sedimentation resuspension and chemistry of particles in the northwest atlantic abstract sediment traps were deployed to sample vertical fluxes of particulate matter both immediately above and within the nepheloid layer on the continental slope and rise of the western north atlantic the data from the traps are used to estimate the settling flux of particles and to attempt to distinguish between the primary flux settling material from the upper water column and the resuspended flux settling material that has been resuspended from some region of the sea floor from these data and from measurements of the net nepheloid standing crop of particles estimates of the mean residence time for particles resuspended in the nepheloid layer are on the order of weeks to months from 15 to 500 m above bottom horizontal advection and diffusion are more important than vertical mixing in maintaining the upper portion of the nepheloid layer the estimated flux of al to the north atlantic as atmospheric dust is one to two orders of magnitude less than the primary flux of al measured just above the nepheloid layer yet the range of accumulation rates of al measured on the sea floor with radioisotopes is close to the values we define as the primary flux horizontal transport of al rich particles mostly aluminosilicates must therefore be significant even above the nepheloid layer the size of 80 90 of the particles collected in the traps both above and within the nepheloid layer was less than 63 m the mean size of particles trapped in the nepheloid layer was about 22 m and above the nepheloid layer 11 m the particles were probably in large aggregates when they encountered the traps but identifiable fecal pellets are only a small fraction of the material collected in the traps between 6 and 15 of the primary production of particulate organic carbon in the euphotic zone was collected in floating sediment traps at the 100 m depth indicating that most particulate organic carbon is recycled in the surface water only 2 3 of primary production of organic carbon was collected as primary flux 500 m above the sea floor from an intercomparison of the composition of particles falling rapidly collected in traps falling slowly or not at all collected in water bottles and resting on the sea floor from core tops it was found that elements associated with biogenic matter such as ca sr cu and i were carried preferentially by the rapidly falling particles once these particles reached the sea floor the concentration of those elements was decreased through decomposition respiration or dissolution dissolution appears to be rapid near or on the sea floor because radiolarians diatoms and juvenile foraminifera were rare in core samples even though abundant in all traps the dynamic nature of the nepheloid layer makes it possible for particles to be resuspended many times before they are finally buried enabling sediment to be carried long distances from its origin the recycling of particles near the sea floor may also increase dissolution of siliceous and carbonate matter

the influence of kinetics on the oxygen isotope composition of calcium carbonate paleotemperature reconstructions rely on knowledge of the equilibrium separation of oxygen isotopes between aqueous solution and calcium carbonate although oxygen isotope separation is expected on theoretical grounds the temperature dependence remains uncertain because other factors such as slow exchange of isotopes between dissolved co2 species and water can obscure the temperature signal this is problematic for crystal growth experiments on laboratory timescales and for interpreting the oxygen isotope composition of crystals formed in natural settings we present results from experiments in which inorganic calcite is precipitated in the presence of 0 25 m dissolved bovine carbonic anhydrase ca the presence of dissolved ca accelerates oxygen isotope equilibration between the dissolved carbon species co2 h2co3 hco3 co32 and water thereby eliminating this source of isotopic disequilibrium during calcite growth the experimental results allow us to isolate for the first time kinetic oxygen isotope effects occurring at the calcite water interface we present a framework of ion by ion growth of calcite that reconciles our new measurements with measurements of natural cave calcites that are the best candidate for having precipitated under near equilibrium conditions our findings suggest that isotopic equilibrium between calcite and water is unlikely to have been established in laboratory experiments or in many natural settings the use of ca in carbonate precipitation experiments offers new opportunities to refine oxygen isotope based geothermometers and to interrogate environmental variables other than temperature that influence calcite growth rates

monitoring of ground surface and subsurface deformations at oil sands using radar interferometry abstractconventional monitoring methods such as surveying and tiltmeter require labor intensive and time consuming fieldwork and they are limited to specific locations either survey stations or an array of tiltmeters furthermore none of the studies about the geomechanical inversion of cumulative surface deformations for the inference of subsurface volumetric changes in canadian oil sands has yet been published radar interferometry has been widely used for monitoring surface deformations over a large area in all weather conditions with high accuracy we have developed a method to detect surface deformations by radar interferometry techniques and to estimate subsurface volumetric changes by geomechanical inversion of surface deformation measurements differential interferometric synthetic aperture radar was implemented using first advanced land observation satellite phased array type l band synthetic aperture radar data the resulting interferograms indicated the vertical surface deformations between

on the use of quasi static deformation to understand reservoir fluid flow deformation above a producing reservoir provides a valuable source of information concerning fluid flow and flow properties quasi static deformation occurs when the displacements are so slow that we may neglect inertial terms in the equations of motion we present a method for inferring reservoir volume change and flow properties such as permeability from observations of quasi static deformation such displacements may represent surface deformation such as tilt leveling interferometric synthetic aperture radar insar or bathymetry observations or subsurface deformation as inferred from time lapse seismic surveys in our approach the equation for fluid flow in a deforming reservoir provides a mapping from estimated fractional volume changes to reservoir permeability variations if the reservoir behaves poroelastically over the interval of interest all the steps in this approach are linear thus the inference of reservoir permeability from deformation data becomes a linear inverse problem in an application to the wilmington oil field in california we find that observed surface displacements obtained by leveling and insar are indeed compatible with measured reservoir volume fluxes we find that the permeability variations in certain layers coincide with fault block boundaries suggesting that in some cases faults are controlling fluid flow at depth

a coupled inversion of pressure and surface displacement a coupled inversion of transient pressure observations and surface displacement measurements provides an efficient technique for estimating subsurface permeability variations the methodology has the advantage of utilizing surface observations which are typically much less expensive than measurements requiring boreholes furthermore unlike many other geophysical observables the relationship between surface deformation and reservoir pore fluid volume changes is relatively well understood our treatment enables us to partition the estimation problem into a sequence of three linear subproblems an application of the approach to a set of tilt and borehole pressure data from the raymond field site in california illustrates its efficiency and utility the observations are associated with a well test in which fluid is withdrawn from a shallow fracture zone during the test 13 tiltmeters recorded the movement of the ground surface simultaneously nine transducers measured pressure changes in boreholes intersecting the fracture system we are able to image a high permeability north trending channel located within the fracture zone the existence and orientation of this high permeability feature is substantiated by a semiquantitative analysis of some 4000 transient pressure curves

a process based model for non equilibrium clumped isotope effects in carbonates abstract the equilibrium clumped isotope composition of carbonate minerals is independent of the composition of the aqueous solution however many carbonate minerals grow at rates that place them in a non equilibrium regime with respect to carbon and oxygen isotopes with unknown consequences for clumped isotopes we develop a process based model that allows one to calculate the oxygen carbon and clumped isotope composition of calcite as a function of temperature crystal growth rate and solution ph in the model carbon and oxygen isotope fractionation occurs through the mass dependent attachment detachment kinetics of the isotopologues of hco 3 and co2 3 to and from the calcite surface which in turn influence the clumped isotope composition of calcite at experimental and biogenic growth rates the mineral is expected to inherit a clumped isotopic composition that is similar to that of the dic pool which helps to explain 1 why different organisms share the same clumped isotope versus temperature calibration curves 2 why many inorganic calibration curves are slightly different from one another and 3 why foraminifera coccoliths and deep sea corals can have near equilibrium clumped isotope compositions but far from equilibrium carbon and oxygen isotope compositions some aspects of the model can be generalized to other mineral systems and should serve as a useful reference in future efforts to quantify kinetic clumped isotope effects

13c 18o isotope signatures and clumped isotope thermometry in foraminifera and coccoliths accurate constraints on past ocean temperatures and compositions are critical for documenting climate change and resolving its causes most proxies for temperature are not thermodynamically based appear to be subject to biological processes require regional calibrations and or are influenced by fluid composition as a result their interpretation becomes uncertain when they are applied in settings not necessarily resembling those in which they were empirically calibrated independent proxies for past temperature could provide an important means of testing and or expanding on existing reconstructions here we report measurements of abundances of stable isotopologues of calcitic and aragonitic benthic and planktic foraminifera and coccoliths relate those abundances to independently estimated growth temperatures and discuss the possible scope of equilibrium and kinetic isotope effects the proportions of 13c 18o bonds in these samples exhibits a temperature dependence that is generally similar to that previously been reported for inorganic calcite and other biologically precipitated carbonate containing minerals apatite from fish reptile and mammal teeth calcitic brachiopods and molluscs aragonitic coral and mollusks most species that exhibit non equilibrium 18o 16o 18o and 13c 12c 13c ratios are characterized by 13c 18o bond abundances that are similar to inorganic calcite and are generally indistinguishable from apparent equilibrium with possible exceptions among benthic foraminiferal samples from the arctic ocean where temperatures are near freezing observed isotope ratios in biogenic carbonates can be explained if carbonate minerals generally preserve a state of ordering that reflects the extent of isotopic equilibration of the dissolved inorganic carbon species

a portable borehole extensometer and tiltmeter for characterizing aquifers 1 the solid skeleton of an aquifer moves in response to changes in water pressure barometric pressure earth tides and other factors and measuring these movements can help characterize aquifers a device for measuring the vertical displacement and horizontal shear or tilt at the same time and place has been developed by combining a tiltmeter and extensometer on a frame that can be temporarily anchored to borehole walls the device can resolve displacements on the order of 10 8 m and tilts on the order of 10 8 rad during a 4 h long pumping test in fractured gneiss the rock contracted by 3 m in response to 2 m of drawdown a compliance of roughly 1 5 m of displacement meter of head change 1 5 10 10 m pa tilt of 10 s of rad to the southwest occurred during pumping and both the displacement and the tilt returned during recovery the tilt signal is repeatable during sequential tests and it changes in magnitude with depth it can be explained by a fracture zone that strikes roughly ew and dips to the south semidiurnal tilts of roughly 0 1 rad occur during ambient conditions at periods of the o1 and m2 earth tides diurnal displacements of several tens of nanometers are associated with ambient fluctuations in water level when barometric pressure changed by several 100 pa increasing barometric pressure causes water level to fall but elevates the total pressure in the well this correlates with dilational displacement while falling total pressure correlates with contraction during ambient conditions

mineralogical assemblages forming at hyperalkaline warm springs hosted on ultramafic rocks a case study of oman and ligurian ophiolites 1 we report on the mineralogical assemblages found in the hyperalkaline springs hosted on liguria and oman ophiolites based on exhaustive x ray diffraction and scanning electron microprobe analyses in liguria hyperalkaline springs produce a thin brownish calcite precipitate that covers the bedrock due to the concomitant atmospheric co2 uptake and neutralization of the hyperalkaline waters no brucite and portlandite minerals are observed the discharge of alkaline waters in oman ophiolite forms white orange precipitates calcium carbonate minerals calcite and or aragonite are the most abundant and ubiquitous precipitates and are produced by the same mechanism as in liguria this process is observed as a thin surface crust made of rhombohedral calcite morphological features of aragonite vary from needle bouquet dumbbell spheroidal like habitus according to the origin of carbon temperature and ionic composition of the hyperalkaline springs and the biochemical and organic compounds brucite is observed both at hyperalkaline springs located at the thrust plane and at the paleo moho the varying mixing proportions between the surface runoff waters and the hyperalkaline ones control brucite precipitation the layered double hydroxide minerals occur solely in the vicinity of hyperalkaline springs emerging within the bedded gabbros finally the dominant mineralogical associations we found in oman ca bearing carbonates and brucite in a serpentinizing environment driven by the meteoric waters are surprisingly the same as those observed at the lost city hydrothermal site in a totally marine environment

a simultaneous inversion of seismic traveltimes and amplitudes for velocity and attenuation it is possible to efficiently use traveltime and amplitude information to infer variations in velocity and q with little additional computation terms accounting for source radiation pattern and receiver coupling may be included in the inversion the methodology is based upon a perturbation approach to paraxial ray theory the perturbation approach linearizes the relationship between velocity deviations and traveltime and amplitude anomalies using the technique we infer the velocity and attenuation structure at a fractured granitic site near raymond california a set of four well pairs are examined and each is found to contain two zones of strong attenuation the velocity variations contain an upper low velocity region corresponding to the uppermost attenuating zone the location of these zones agrees with independent well log and geophysical data the velocity and attenuation anomalies appear to coincide with extensively fractured sections of the borehole and may indicate fracture zones rather than individual fractures

a quadratic element method for evaluating groundwater flow by the inversion of surface tilt with application to the tono area japan summary by modifying a previous method with constant elements we developed a quadratic element method for more accurately estimating groundwater flow by the inversion of tilt data in this method 1 a region of groundwater flow is divided into quadratic elements in which the change in groundwater volume per unit volume of rock v and the skempton coefficient b vary in a quadratic manner with the coordinates 2 the values of v are set to zero at the boundaries of the region of groundwater flow and 3 the sum of the squared second derivatives of v is adopted as a constraining condition that is weighted and added to the sum of the squared errors in tilt first analyses were performed for a flow model to determine the accuracy of this method for estimating groundwater flow and also to clarify the effect of the assumed size of a region of groundwater flow these analyses showed that the quadratic element method proposed in this study gives a much better estimation of v than the constant element method and that a large region of groundwater flow should be assumed rather than a small region since the values of v at points outside of the actual region of groundwater flow are estimated to be nearly zero when a large region is assumed while these values are greatly overestimated when an excessively small region is assumed finally the quadratic element method was applied to the site of the mizunami underground research laboratory in the tono area japan inverse analyses were performed for tilt data measured by four tiltmeters with a resolution of 10 9 radians during the excavation of two shafts under the assumption that the rock mass is an isotropic and homogeneous half space the results showed that the method proposed in this study reproduced the tilt data very accurately thus the distribution of v was estimated without sacrificing the reproducibility of the tilt data the contour maps of b 1 v poisson s ratio showed that the heterogeneous flow of groundwater occurred at the site and that groundwater volume decreased mainly in the area surrounded by two faults the latter result is consistent with the finding obtained by previous investigations that these faults have low permeability in the direction perpendicular to the strike and may act as a flow barrier

devils hole paleotemperatures and implications for oxygen isotope equilibrium fractionation subaqueous calcite in devils hole nevada was growing continuously from slightly super saturated groundwater providing a 570 kyr long o18 paleoclimate record due to its very slow growth it has been assumed to have grown under conditions of isotopic equilibrium however its holocene o18 value is 1 5 higher than predicted by laboratory precipitation based oxygen isotope thermometer calibrations the suggestion that devils hole calcite anchors the isotope thermometer to more 18o enriched values has stirred a debate as to which paleothermometer calibration is relevant for paleoclimate and casts doubt on the validity of o18 based paleotemperatures we used clumped isotopes to test the assumptions of the devils hole alternative 18o thermometer carbonate clumped isotopes are a temperature proxy that measures the abundance of 13c18o bonds in caco3 this proxy is independent of the water composition and therefore gives independent estimates of temperatures when calcite forms at thermodynamic and isotopic equilibrium we find that devils hole water paleotemperatures were constant at 30 6 2 6 c between 27 and 180 ka similarly to the modern groundwater temperature of 32 8 34 3 c the proximity of the devils hole clumped isotope data to values expected based on modern groundwater temperatures supports the notion that devils hole calcite grew under equilibrium conditions therefore the commonly used laboratory based o18 temperature calibrations should be reconsidered the constant water temperature over the glacial interglacial cycles indicates that the long devils hole o18 record reflects only variations in the groundwater o18 values and as such represents a valuable archive of paleoclimate and isotope paleohydrology

using surface deformation to image reservoir dynamics the inversion of surface deformation data such as tilt displacement or strain provides a noninvasive method for monitoring subsurface volume change reservoir volume change is related directly to processes such as pressure variations induced by injection and withdrawal the inversion procedure is illustrated by an application to tiltmeter data from the hijiori test site in japan an inversion of surface tilt data allows us to image flow processes in a fractured granodiorite approximately 650 barrels of water injected 2 km below the surface produces a peak surface tilt of the order of 0 8 microradians we find that the pattern of volume change in the granodiorite is very asymmetrical elongated in a north northwesterly direction and the maximum volume change is offset by more than 0 7 km to the east of the pumping well the inversion of a suite of leveling data from the wilmington oil field in long beach california images large scale reservoir volume changes in 12 one to two year increments from 1

estimation of 3 d surface displacement based on insar and deformation modeling a new approach is presented for mapping 3 d surface displacement caused by subsurface fluid volumetric change based on 1 d interferometric synthetic aperture radar insar line of sight measurements and surface deformation modeling the relationship between surface deformation and source fluid volumetric change is modeled according to elastic half space theory a distinctive advantage of the proposed approach is that it effectively extends the capability of the sun synchronous orbit side looking synthetic aperture radar that has been essentially only able to measure 1 d displacements accurately or at most 2 d displacements when insar measurements from more than one orbit or platform are combined experimental studies are carried out with both simulated and real data sets to test the performance of the method the results have demonstrated that the approach works very well