highland contamination in lunar mare soils improved mapping with multiple end member spectral mixture analysis mesma 1 multiple end member spectral mixture analysis mesma was applied to the clementine uvvis global 1 km multispectral data set and the resulting highland material fraction image was used to investigate highland contamination of mare surfaces by impact cratering mesma decomposes each pixel with the number of end members fewer than the number of the spectral bands of clementine uvvis data this allows the use of variable end member combinations to accommodate global spectral variance a 13 end member set of lunar soil components that spans the lunar spectral diversity was selected from the uvvis data and included 1 mature and 4 fresh highland soils 4 mature and 2 fresh mare soils and 2 soils of dark mantling materials this set was applied to the lunar data through mesma and an aggregated global highland abundance was derived comparison of the highland fraction results from mesma and traditional spectral mixture analysis sma demonstrated that mesma better accommodates the compositional variation of mare soils resulting in a greater accuracy in the measurement of highland with the derived products we investigated highland contamination in mare nectaris mare fecunditatis and mare crisium these mare surfaces are proximal to the large craters theophilus taruntius langrenus and proclus and provided an opportunity to investigate highland contamination by large impacts the analyses indicated that theophilus impact resulted in highland contamination of 20 80 on most of mare nectaris while taruntius and langrenus impacts caused 5 40 contamination of mare fecunditatis the trend of minimal highland abundance in mare fecunditatis correlates poorly with basalt thickness suggesting an efficient lateral mixing due to the large craters taruntius and langrenus additionally proclus combining with other craters was responsible for highland contamination in most of the mare crisium surface and some basalt classification in this mare reflects highland contamination of the spectral properties mesma significantly reduces uncertainty in calculating global composition variations due to mixing and these analyses demonstrate that large impacts played a dominant role in delivering highland materials onto three mare surfaces

resolving three dimensional surface displacements from insar measurements a review abstract one dimensional measurement along the line of sight los direction has greatly limited the capability of insar technique in the investigation of surface displacements and their dynamics in recent years great efforts have been made to resolve complete three dimensional 3 d displacements from insar measurements this contribution is intended to provide a systematic review of the progress achieved in this field based on an analysis of the insar los measurements we first cover two commonly used techniques i e offset tracking and multi aperture insar mai with which the surface displacement in the azimuth direction can be measured together with the los displacement several methods for mapping 3 d displacements using insar measurements are subsequently presented and categorized into three groups i combination of multi pass los and azimuth measurements ii integration of insar and gps data and iii prior information assisted approaches the strengths and weaknesses of each method are analyzed to show the applicability of each method to specific 3 d displacement mapping cases in hope to provide a useful guidance in choosing a suitable approach accordingly finally suggestions for resolving the challenging issues and outlook of future research are given

clustered impacts experiments and implications impact by clusters of projectiles rather than a single projectile can result from several processes atmospheric breakup tidal breakup and ejecta from a large primary impact experiments have been performed in order to establish the characteristics of such events over a wide range of impact velocities 15 m s to 6 km s at very low impact velocities 15 200 m s clustered impacts were produced by launching a grouped projectiles of aluminum shot steel shot iron filings and sand at moderate to high velocities 0 8 6 km s pyrex spheres were shattered above the target during passage through aluminum foil or paper thereby forming a well defined cluster of fragments of overall radius rc the ratio of the overall radius rc of the cluster to the radius rs of a solid impactor of the same mass provides a measure of the cluster dispersion sand and compacted pumice targets were used in order to compare qualitatively the additional effect of slight differences in target strength the experiments reveal marked contrasts between impacts by clusters of projectiles and impacts by a single solid body tight clusters rc rs 20 displace a factor of 10 less mass this reduction in cratering efficiency is largely expressed as a shallow crater with an aspect ratio diameter depth as large as 30 for open clusters the size and velocity of the cluster as well as the density and strength contrast between the impactor and target can dramatically affect crater morphology open clusters impacting compacted pumice produce a flat hummocky floor with an incipient multiring pattern whereas a tight cluster impacting the same target produces a central floor mound oblique impacts by symmetrical clusters form a characteristic array of v shaped ridges pointing uprange the apex angle of the ridges depends on the cluster dispersion and impact angle inventories of postimpact projectile material reveal that the projectile is largely retained on the surface and spread downrange from the impact direction the amount of projectile material retained on the surfaces increases with decreasing impact angle from the horizontal and with increasing strength of the target relative to the projectile clustered impact craters and lunar secondary craters bear striking similarities over a broad range of morphologic features on this basis and on the basis of reasonable models of ejecta curtain structure we suggest that these experiments provide new clues for understanding ejecta emplacement around large lunar impact craters when the ejecta curtain around large impacts is viewed as a thick wall of debris and clustered impactors are viewed as a unit section of such a curtain then experimental results indicate that the continuous ejecta facies even for lunar craters larger than 100 km could contain as much as 90 primary material such a conclusion contrasts with many existing models that derive mixing ratios implicitly based on single noninteracting impact events beyond the continuous ejecta facies impacting clusters of ejecta provide a physical basis for understanding the wide variety of secondary morphologies and the large range in spectral signatures of primary material in crater rays

distinguishing high alumina mare basalts using clementine uvvis and lunar prospector grs data mare moscoviense and mare nectaris 1 high alumina ha mare basalts are a unique group of the lunar sample collection sample geochemistry indicates that these basalts are derived from sources composed of late stage cumulates from the lunar magma ocean lmo their aluminous nature suggests their sources contained significant plagioclase which has implications regarding the efficiency of plagioclase separation from earlier forming mafic cumulates in the lmo to form the anorthositic lunar crust and hence the heterogeneity of the lunar mantle the apollo and luna missions sampled ha basalts from four different locations that are separated by 80 equatorial degrees 2400 km radiometric age dating of these samples demonstrates aluminous basaltic volcanism spanned over 1 billion years suggesting ha basalts may be more prevalent on the moon than implied by the sample population knowing their global occurrence would ultimately enhance our understanding of lunar evolution aluminous mare basalts occupy a unique location in th feo compositional space that suggests they can be identified using global remote sensing data of the moon we present our approach for distinguishing exposures of ha basalts using clementine ultraviolet visible infrared uvvis and lunar prospector gamma ray spectrometer lp grs data with constraints based on the feo tio2 and th abundances of apollo and luna ha samples we identified 34 regions of interest rois where ha basalts could be a prominent component of the lunar surface by analyzing the rims and proximal ejecta from small impacts 0 4 4 km in diameter into the mare surface we characterized compositionally distinct basaltic units that make up the mare and thus determined which units represent ha basalt lavas the results were used to generate maps that depict discrete mare units and classify their general basalt type here we focus on two rois mare moscoviense and mare nectaris mare moscoviense is composed of four basaltic units two of which are ha candidates clementine uvvis data of mare nectaris show evidence of up to three mare basalt units one is the remnants of a mid ti unit that capped earlier low ti flows the majority of the basin is filled by a compositionally indistinguishable low fe low ti basalt however spectral profiles suggest there are two units regardless the units both fit the criteria for a ha basalt

persistent scatterer interferometric synthetic aperture radar for crustal deformation analysis with application to volcan alcedo galapagos 1 while conventional interferometric synthetic aperture radar insar is a very effective technique for measuring crustal deformation almost any interferogram includes large areas where the signals decorrelate and no measurement is possible persistent scatterer ps insar overcomes the decorrelation problem by identifying resolution elements whose echo is dominated by a single scatterer in a series of interferograms existing ps methods have been very successful in analysis of urban areas where stable angular structures produce efficient reflectors that dominate background scattering however man made structures are absent from most of the earth s surface furthermore existing methods identify ps pixels based on the similarity of their phase history to an assumed model for how deformation varies with time whereas characterizing the temporal pattern of deformation is commonly one of the aims of any deformation study we describe here a method for ps analysis stamps that uses spatial correlation of interferogram phase to find pixels with low phase variance in all terrains with or without buildings prior knowledge of temporal variations in the deformation rate is not required for their identification we apply stamps to volcan alcedo where conventional insar fails because of dense vegetation on the upper volcano flanks that causes most pixels to decorrelate with time we detect two sources of deformation the first we model as a contracting pipe like body which we interpret to be a crystallizing magma chamber the second is downward and lateral motion on the inner slopes of the caldera which we interpret as landsliding

assessments of serious anthropogenic land subsidence in yunlin county of central taiwan from 1996 to 1999 by persistent scatterers insar article i nfo anthropogenic ground subsidence due to massive pumping of groundwater is one of the severe environmen tal hazards in taiwan the yunlin county located in the southwestern coastal region of taiwan is one of the most counties with serious land subsidence because of the agricultural needs in certain areas of the region the subsidence rate reaches as much as 14 3 cm yr the severe land subsidence gives rise to the risk of flood hazard and damage of infrastructures in this area we represented a persistent scatterers insar psinsar results deduced from 1996 to 1999 time span for monitoring of land subsidence in this area the psinsar results show that baojhou tuku and yuanchang townships reveal a maximum subsidence rate of about 7 8 cm yr along the los and lunbei township located on the northern yunlin reveals a subsidence rate of 3 5 cm yr which is quite coincident with the precise leveling result this result has proven that the effective reduction of labor and cost could be achieved by using this technique on monitoring land subsidence in

lithological mapping of central part of mare moscoviense using chandrayaan 1 hyperspectral imager hysi data abstract we conducted spectral analysis of central region of the mare moscoviense area on the far side of the moon using the hyperspectral imager hysi data from the chandrayaan 1 mission in an effort to identify and map the major lithological units present in the area various spectral band parameters namely band curvature band tilt and band strength have been used for lithological discrimination based on the nature of the spectral profile these band parameters essentially measure the shape position and strength of the absorption feature near 1000 nm arising due to electronic transition of fe 2 in crystallographic sites of major rock forming silicates spectral band parameters have been used for generating rock type composite image based on spectral studies and rock type composite image as obtained using band parameters five major compositional units have been identified highland basin soils ancient mature mare highland contaminated mare buried unit with abundant low ca pyroxene lcp and youngest mare unit in the present study a multispectral approach in the form of spectral band parameters has been adopted for analysing the hysi hyperspectral data from chandrayaan 1 mission present study clearly shows that the spectral band parameters obtained using selected hysi channels could efficiently be used to discriminate and delineate the major litho units present across the central part of mare moscoviense and the same approach can thus be used for lithological mapping of other parts of lunar surface using hysi data

the nature of crater rays the copernicus example crater rays are formed during a cratering event as target material is ballistically ejected to distances of many crater radii forming narrow generally high albedo approximately linear features extending outward from the crater the nature of crater rays was examined for the lunar crater copernicus using new information on the composition of surface material from near ir reflectance measurements surface roughness from radar backscatter measurements and photogeologic data from available images part of the data analysis included use of mixing models to quantify the mixing systematics observed between primary ejecta and local substrate of the ray on the basis of compositional parameters from reflectance spectra primary material from copernicus can be detected in the surface material of rays in decreasing amounts with increasing radial distance e g 20 25 primary ejecta at six crater radii for distances greater than three crater radii the proportion of local material to primary ejecta observed from these compositional reflectance data is approximately equal to that predicted by previous laboratory and ballistic studies of craters within three crater radii the compositional data indicate a higher proportion of primary ejecta than predicted for extended areas along the ray that do not contain large secondary craters the primary ejecta is intimately mixed on the granular scale with local material throughout the regolith the relatively high albedo of the rays of copernicus is due to the feldspathic composition highland of the primary ejecta in rays emplaced on a mare substrate immature local substrate is only observed in copernicus s ray at large unmantied secondary craters or other areas with sufficient topographic slope to prevent the accumulation of mature soils crater rays are filamentous generally high albedo features that emanate nearly radially from young impact structures rays are narrow in relation to the crater radius extend distally for many crater radii and constitute a distinctive albedo feature around some of the largest and freshest lunar craters visible from earth synoptic views of ray systems figure la give the strong impression that the rays comprise bright material that has been excavated from the crater cavity and been emplaced beyond the continuous ejecta deposit if this visual impression is correct then the process that forms crater rays represents a significant mechanism for the lateral transport of primary material to great distances from its point of origin and particularly for craters larger than a let tens of kilometers in diameter constitutes a fundamental process for the regional mixing of crustal materials earth based telescopic images of the moon allowed the first studies and descriptions of rays and ray systems shoemaker 1962 described the arcuate and loop shaped streaks of the copernicus ray systems and showed that these patterns could be locally resolved into individual en echelon feather shaped elements 15 20 km in length with their long axes oriented approximately radially to the crater he noted the presence of elongate depressions or gouges in the ray system ranking in diameter from 8 km down to the limits of resolution and generally located at the proximal ends of the individual ray elements shoemaker observed that some of the gouges were

merging spatial and spectral datasets to place olivine in stratigraphic context at arruntia crater a rare window into vesta s northern hemispheric crust abstract a major goal of the dawn mission to vesta was to test and refine current models of the asteroid s formation by characterizing the distribution of mineral components on its surface detection of the mineral olivine by the visible and infrared mapping spectrometer vir and the framing camera fc onboard dawn was a key milestone in this effort and was expected to help resolve a debate regarding the dominant mode of vesta s petrologic evolution i e magma ocean vs serial magmatism however the subtleties of the olivine spectral signature combined with the small size of individual olivine rich exposures tens of meters prohibits detailed mapping of this petrologically significant mineral component when the data from either instrument are evaluated independently as a result the particular role of these olivine exposures in vesta s geologic history remains largely unresolved here we fully characterize the type locality of vesta s olivine rich materials the northern hemisphere craters bellicia and arruntia using a novel data fusion approach for linking the vir and fc datasets specifically we have leveraged a spectral mixture analysis framework to create a new dataset that maps or extrapolates full resolution spectra derived from vir data onto the higher spatial resolution of fc when used as an exploratory tool in conjunction with the original fc and vir data the new extrapolated dataset reveals important new details about the distribution of olivine around bellicia and arruntia craters there are clear compositional distinctions between the exposures at the two craters with a much stronger olivine component in the walls of bellicia than arruntia the proximal arruntia ejecta appear more consistent with high proportions of an evolved high calcium pyroxene as in eucrites than with an enhanced olivine component examples of diogenite rich howardite also occur in the region further we leverage arruntia s role as the freshest large crater in the northern hemisphere and thus a rare window into the vesta s northern hemispheric crust to suggest an overall stratigraphy for the region a thin veneer of howardite overlies a sequence of diogenite rich near surface olivine rich intermediate and eucrite rich materials at depth the manner of exposure of these various components in a marked stratification point to a plutonic model for emplacing these mineralogically unique components in the near surface of vesta

mineralogy of the mafic anomaly in the south pole aitken basin implications for excavation of the lunar mantle the mineralogy of south pole aitken basin spa the largest confirmed impact basin on the moon is evaluated using five color images from clementine although olivine rich material as well as basalts rich in clinopyroxene are readily identified elsewhere on the farside the dominant rock type observed across the interior of spa is of a very noritic composition this mineralogy suggests that lower crust rather than the mantle is the dominant source of the mafic component at spa the lack of variation in observed noritic composition is probably due to basin formation processes during which extensive melting and mixing of target materials are likely to occur

geology of mare deposits in south pole aitken basin as seen by clementine uv vis data a multispectral analysis of 21 discrete lunar mare deposits within the south pole aitken basin was undertaken in order to model the general mineralogical composition of farside mare deposits so that the near and farside may be compared in terms of magma generation and emplacement determination of each deposit s mineralogy was based upon albedo the 0 75 0 95 m ratio indicating the presence of a 1 0 m absorption band and the strength and shape of that band a combination of improved spatial resolution and the availability of the general multispectral signature for each pond allowed deposits to be examined for homogeneity in order to assess the nature and number of flows represented feo and tio 2 abundances were also estimated based upon the resultant data 19 out of 21 ponds were determined to be mare deposits of these 19 15 had spectra well defined enough to classify general mineralogy nine having high ca pyroxene signatures indicative of basalt and six showing low ca signatures suggesting a substantial noritic component we believe these noritic signatures can plausibly be attributed to vertical lateral soil mixing processes for the smallest ponds although a unique lithology cannot be ruled out for the largest pond a majority of ponds in this study region have homogeneous spectral signatures interpreted to represent individual eruptive phases this indicates that very large volumes for these regions may be typical also because such volumes are comparable to the largest terrestrial eruptions they may have formed by a similar mechanism of emplacement the vast majority of mature soils are spectrally redder and thus have a lower estimated feo abundance than the mare serenitatis soil standard ms 2 in particular and nearside basalts in general these soils also average low to medium estimated tio 2 abundance similar to apollo 12 and 15 and luna 24 the observations made here are consistent with a scenario in which basalts with low feo and low to medium tio 2 contents were deposited during the lunar peak volcanic period that occurred in the late imbrian 3 80 3 20 ga and because of their small areal extent were more susceptible to mixing processes than nearside basalts

land subsidence in mashhad valley northeast iran results from insar levelling and gps summary significant land subsidence was recently recognized in northeast iran near the city of mashhad precise levelling surveys performed in 1995 2002 and 2005 indicate as much as 90 cm of subsidence during the 1995 2005 period continuous gps monitoring approximately 8 km northwest of mashhad city shows more than 20 cm yr 1 subsidence between 2005 and 2006 we use interferometric synthetic aperture radar insar measurements to detect the temporal and spatial pattern of this surface deformation 13 interferograms from 10 c band sar images acquired by the enivsat satellite from 2003 to 2005 are analysed and stacked our insar mapping suggests that subsidence occurs within a northwest southeast elongated ellipticshaped bowl along the axis of the mashhad valley with a peak amplitude of 28 30 cm yr 1 for the 2003 2005 time period the insar data indicate that approximately 70 km 2 in the valley floor including the northwestern part of mashhad city subsided at a rate exceeding 15 cm yr 1 between 2003 and 2005 and that the subsidence area is structurally controlled by the trends of quaternary faults cutting the valley floor analysis of piezometric records suggests that subsidence likely results from extensive overdrafting of the aquifer system in the valley that has caused as much as 65 m of water table decline since 1960s

detection of aquifer system compaction and land subsidence using interferometric synthetic aperture radar antelope valley mojave desert california interferometric synthetic aperture radar insar has great potential to detect and quantify land subsidence caused by aquifer system compaction insar maps with high spatial detail and resolution of range displacement 10 mm in change of land surface elevation were developed for a groundwater basin 103 km2 in antelope valley california using radar data collected from the ers 1 satellite these data allow comprehensive comparison between recent 1993 1995 subsidence patterns and those detected historically 1926 1992 by more traditional methods the changed subsidence patterns are generally compatible with recent shifts in land and water use the insar detected patterns are generally consistent with predictions based on a coupled model of groundwater flow and aquifer system compaction the minor inconsistencies may reflect our imperfect knowledge of the distribution and properties of compressible sediments when used in conjunction with coincident measurements of groundwater levels and other geologic information insar data may be useful for constraining parameter estimates in simulations of aquifer system compaction

atmospheric effects in interferometric synthetic aperture radar surface deformation and topographic maps interferogram images derived from repeat pass spaceborne synthetic aperture radar systems exhibit artifacts due to the time and space variations of atmospheric water vapor other tropospheric variations such as pressure and temperature also induce distortions but the effects are smaller in magnitude and more evenly distributed throughout the interferogram than the wet troposphere term spatial and temporal changes of 20 in relative humidity lead to 10 cm errors in deformation products and perhaps 100 m of error in derived topographic maps for those pass pairs with unfavorable baseline geometries in wet regions such as hawaii these are by far the dominant errors in the spaceborne imaging radar c and x band synthetic aperature radar sir c x sar interferometric products the unknown time delay from tropospheric distortion is independent of frequency and thus multiwavelength measurements such as those commonly used to correct radar altimeter and global positioning system gps ionospheric biases cannot be used to rectify the error in the topographic case the errors may be mitigated by choosing interferometric pairs with relatively long baselines as the error amplitude is inversely proportional to the perpendicular component of the interferometer baseline for the sir c x sar hawaii data we found that the best longest baseline pair produced a map supporting 100 m contouring whereas the poorest baseline choice yielded an extremely noisy topographic map even at this coarse contour interval in the case of deformation map errors the result is either independent of baseline parameters or else very nearly so here the only solution is averaging of independent interferograms so in order to create accurate deformation products in wet regions many multiple passes may be required rules for designing optimal data acquisition and processing sequences for interferometric analyses in nondesert parts of the world are 1 to use the longest radar wavelengths possible within ionospheric scintillation and faraday rotation limits 2 for topography maximize interferometer baseline within decorrelation limits and 3 for surface deformation use multiple observations and average the derived products following the above recipe yields accuracies of 10 m for digital elevation models and 1 cm for deformation maps even in very wet regions such as hawaii

the titanium contents of lunar mare basalts lunar mare basalt sample data suggest that there is a bimodal distribution of tio2 concentrations using a refined technique for remote determination of tio2 we find that the maria actually vary continuously from low to high values the reason for the discrepancy is that the nine lunar sample return missions were not situated near intermediate basalt regions moreover maria with 2 4 wt tio2 are most abundant and abundance decreases with increasing tio2 maria surfaces with tio2 5 wt constitute only 20 of the maria although impact mixing of basalts with differing ti concentrations may smear out the distribution and decrease the abundance of high ti basalts the distribution of basalt ti contents probably reflects both the relative abundances of ilmenite free and ilmenite bearing mantle sources this distribution is consistent with models of the formation of mare source regions as cumulates from the lunar magma ocean

shocked plagioclase signatures in thermal emission spectrometer data of mars abstract the extensive impact cratering record on mars combined with evidence from snc meteorites suggests that a significant fraction of the surface is composed of materials subjected to variable shock pressures pressure induced structural changes in minerals during high pressure shock events alter their thermal infrared spectral emission features particularly for feldspars in a predictable fashion to understand the degree to which the distribution and magnitude of shock effects influence martian surface mineralogy we used standard spectral mineral libraries supplemented by laboratory spectra of experimentally shocked bytownite feldspar johnson j r horz f christensen p lucey p g 2002b j geophys res 107 e10 doi 10 1029 2001je001517 to deconvolve thermal emission spectrometer tes data from six relatively large 50 km impact craters on mars we used both tes orbital data and tes mosaics emission phase function sequences to study local and regional areas near the craters and compared the differences between models using single tes detector data and 3 2 detector averaged data inclusion of shocked feldspar spectra in the deconvolution models consistently improved the rms errors compared to models in which the spectra were not used and resulted in modeled shocked feldspar abundances of 15 in some regions however the magnitudes of model rms error improvements were within the noise equivalent rms errors for the tes instrument hamilton v personal communication this suggests that while shocked feldspars may be a component of the regions studied their presence cannot be conclusively demonstrated in the tes data analyzed here if the distributions of shocked feldspars suggested by the models are real the lack of spatial correlation to crater materials may reflect extensive aeolian mixing of martian regolith materials composed of variably shocked impact ejecta from both local and distant sources

remote sensing and geologic studies of the balmer kapteyn region of the moon 1 the balmer kapteyn b k region is located just east of mare fecunditatis on the east limb of the moon it is centered on the balmer kapteyn basin a pre nectarian impact structure that exhibits two rings approximately 225 km and 450 km in diameter clementine multispectral images and lunar prospector lp gamma ray spectrometer grs data were used to investigate the composition age and origin of geologic units in the region a major expanse of cryptomare was mapped within the b k basin spectral and chemical data obtained for dark haloed craters dhcs established that these impact craters excavated mare basalt from beneath higher albedo highland rich surface units the buried basalts exposed by dhcs in the region are dominated by low titanium mare basalts the fresh dhc feo values 15 0 15 7 wt that best represent those of buried mare basalts are well within the range of values exhibited by high alumina mare basalts while most cryptomare deposits occur beneath surfaces that range in age from imbrian to nectarian it is possible that some mare flows were emplaced during pre nectarian time most cryptomare deposits in the b k region were formed by the contamination of mare surfaces by highland rich distal ejecta from surrounding impact craters these balmer type cryptomare deposits are usually associated with light plains units major lp grs feo enhancements are associated with cryptomaria in the balmer kapteyn lomonosov fleming schiller schickard and mendel rydberg regions

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

mapping the feo and tio2 content of the lunar surface with multispectral imagery the derivation of quantitative elemental concentrations from multispectral imaging of the moon has long been a goal of lunar remote sensing concentration maps at the spatial resolutions available from the recent clementine mission would provide a revolutionary new tool for understanding the origin and evolution of the lunar crust lucey et al 1995 presented a method for extracting the concentration of fe from multispectral imaging of the moon this paper examines and quantifies important aspects ofthat technique left unexamined by lucey et al which had the potential to severely limit its utility these aspects include the effects of maturity grain size mineralogy shading due to topography and the presence of glass we also present a new algorithm for derivation of tio2 from multispectral imaging of both mare and highland units we find that both techniques are only weakly sensitive to maturity and that they have about 1 wt accuracy based on examination of the spectral properties and compositions of resolved lunar sampling stations presented by blewett et al 1997 we also discuss these findings in the context of two contrasting views of the effect of composition on lunar spectral properties presented by pieters and coworkers and hapke and coworkers we find the view of hapke and coworkers to be more consistent with our observations using a global mosaic of clementine multispectral data and these element derivation algorithms we find that the global modal abundance of feo is 4 5 wt 1 wt and the global modal abundance of tio2 is 0 45 wt 1 wt

lunar regional dark mantle deposits geologic multispectral and modeling studies clementine five channel uv visible uvvis data have been used to study seven regional dark mantle deposits dmds on the moon the dmds were mapped in distribution to determine their extent and stratigraphic relationship to other geologic units based upon the spectral properties for each dmd the crystallization of the beads in each deposit was inferred and used to estimate cooling rates in the volcanic plumes that emplaced the deposits deposits with a high concentration of glasses reflect volcanic plumes that had low optical densities and high cooling rates whereas deposits dominated by crystallized beads indicate plumes with slower cooling rates due to higher optical densities spectral data from each of the regional dmds show that their glass crystallized bead ratio can be estimated based upon their 415 750 and 750 950 nm values and comparison to laboratory spectra for the beads patches of young dark mantle in the sinus aestuum dmd represent one extreme with the bluest color highest 415 750 and weakest glass band absorption lowest 750 950 of all the dmds at the other extreme is the aristarchus plateau dmd with the reddest color and strongest glass band absorption the other nearside dmds including taurus littrow sulpicius gallus rima bode and mare vaporum lie between these two extremes due to intermediate mixtures of the crystallized beads and glasses with other local soils the orientale ring dmd on the western limb is dominated by volcanic glasses and is spectrally similar to the localized dmds found in alphonsus crater we have identified a central vent for the orientale ring dmd and model the eruption as degassing of a near surface dike to produce a 20 km high umbrella shaped plume with ejection velocities of 360 m s and deposition of the glasses at an average radius of 80 km from the vent although we cannot identify the exact sources for the other regional dmds probably because they are buried beneath younger mare the eruptions most likely resulted from dikes breaching the surface and producing a volcanic plume dominated by larger greater than submillimeter hot clasts that formed mare and sinuous rules the small percent of clasts that form the volcanic beads are carried by the expanding gas cloud to large distances in some cases 100 km to produce the observed continuous regional dmds the lack of basalt samples that can be petrologically related to the volcanic glasses may be a result of their spatial separation with the basalts flowing into the basins while the beads are deposited both into the basins and on the adjacent highlands

crustal diversity of the moon compositional analyses of galileo solid state imaging data the multispectral images of the lunar limb and farside obtained by the solid state imaging ssi system on board the galileo spacecraft provide the first new pulse of compositional data of the moon by a spacecraft in well over a decade the wavelength range covered by ssi filters 0 4 1 0 m is particularly sensitive to the composition of mare basalts the abundance of mafic ferrous minerals and the maturity of the regolith to a first order the limb and farside material is consistent with previous characterization of nearside lunar spectral types for mare and highland soils and craters most basalts are of an intermediate tio 2 composition and most of the highland crust is feldspathic with local variations in mafic content identified principally at impact craters dark manfling material on the farside can be interpreted in terms of known properties of lunar pyroclastic glass regions of cryptornate are shown to have spectral properties intermediate between those of highland and mare soils as would be expected from a mixture of the two there are several important exceptions and surprises however unlike the basalt types identified on the nearside limb and farside basalts exhibit an exceptionally weak 1 xm ferrous absorption band this may indicate a compositionally distinct lunar basalt group that for example is more mg rich than most basalts of the nearside some of the most notable compositional anomalies are associated with south pole aitken basin this large region has a much lower albedo than surrounding highlands the inner darkest portion of the basin exhibits optical properties indistinguishable low ti basalts deposits to the south exhibit unique properties with a strong and broad ferrous 1 xrn absorption most consistent with abundant olivine the unusual compositions associated with south pole aitken and their spatial e3tent suggests the impact creating this huge lunar basin excavated mafic rich lower crust or perhaps mantle material 1 intro oucri ion

sar monitoring of progressive and seasonal ground deformation using the permanent scatterers technique spaceborne differential radar interferometry has proven a remarkable potential for mapping ground deformation phenomena e g urban subsidence volcano dynamics coseismic and postseismic displacements along faults as well as slope instability however a full operational capability has not been achieved yet due to atmospheric disturbances and phase decorrelation phenomena these drawbacks can often be at least partially overcome by carrying out measurements on a subset of image pixels corresponding to natural or artificial stable reflectors permanent scatterers ps and exploiting long temporal series of interferometric data this approach allows one to push the measurement precision very close to its theoretical limit in the order of spl sim 1 mm for c band european remote sensing ers like sensors in this paper the detection of both time uniform and seasonal deformation phenomena is addressed and a first assessment of the precision achievable by means of the ps technique is discussed results highlighting deformation phenomena occurring in two test sites in california are reported fremont in the southern bay area and san jose in the santa clara valley

sensing the ups and downs of las vegas insar reveals structural control of land subsidence and aquifer system deformation land subsidence in las vegas nevada united states between april 1992 and december 1997 was measured using spaceborne interferometric synthetic aperture radar the detailed deformation maps clearly show that the spatial extent of subsidence is controlled by geologic structures faults and sediment composition clay thickness the maximum detected subsidence during the 5 75 yr period is 19 cm comparison with leveling data indicates that the subsidence rates declined during the past decade as a result of rising ground water levels brought about by a net reduction in ground water extraction temporal analysis also detects seasonal subsidence and uplift patterns which provide information about the elastic and inelastic properties of the aquifer system and their spatial variability

surface deformation from persistent scatterers sar interferometry and fusion with leveling data a case study over the choushui river alluvial fan taiwan abstract the choushui river alluvial fan craf one of the most important agricultural areas in taiwan suffers severe subsidence caused by groundwater withdrawal we use 20 envisat images from 2006 to 2008 to derive vertical deformation over craf by persistent scatterer interferometry psi which effectively reduces errors affecting conventional dinsar techniques the pixel density over craf is 107 6 pixels km 2 compared to 0 19 points km 2 of the leveling benchmarks psi yields vertical displacements matching the leveling result to 0 6 cm year rms and provides a higher spatial resolution of subsidence than the latter we also develop a data fusion method that considers the high precision low point density leveling result as a smoothed correction to the psi result the combined field is more representative of overall deformation characteristics than the psi only or leveling only field and it is better suited for the assessment of the impact of subsidence over craf

mineralogy of the lunar crust results from clementine received 1997 december 5 accepted in revised form 1998 september 15 abstract the central peaks of 109 impact craters across the moon are examined with clementine ultraviolet visible uvvis camera multispectral data the craters range in diameter from 40 to 180 km and are believed to have exhumed material from 5 30 km beneath the surface to form the peaks including both upper and lower crustal rocks depending on whether craters have impacted into highlands or basins representative five color spectra from spectrally and spatially distinct areas within the peaks are classified using spectral parameters including key ratio which is related to mafic mineral abundance and spectral curvature linked to absorption band shape which distinguishes between low and high ca pyroxene and olivine the spectral parameters are correlated to mineralogical abundances related in turn to highland plutonic rock compositions the derived rock compositions for the various central peaks are presented in a global map from these results it is evident that the lunar crust is compositionally diverse both globally and at local 100 m scales found within individual sets of central peaks although the central peaks compositions imply a crust that is generally consistent with previous models of crustal structure they also indicate a more anorthositic crust than generally assumed with a bulk plagioclase content of 8 1 evolving from pure anorthosite near the surface towards more mafic low ca pyroxene rich compositions with depth comparable to anorthositic norite evidence for mafic plutons occurs in both highlands and basins and represent all mafic highland rock types however the lower crust is more compositionally diverse than the highlands with both a greater range of rock types and more diversity within individual sets of central peaks

a new method for measuring deformation on volcanoes and other natural terrains using insar persistent scatterers 1 we present here a new insar persistent scatterer ps method for analyzing episodic crustal deformation in non urban environments with application to volcanic settings our method for identifying ps pixels in a series of interferograms is based primarily on phase characteristics and finds low amplitude pixels with phase stability that are not identified by the existing amplitude based algorithm our method also uses the spatial correlation of the phases rather than a well defined phase history so that we can observe temporally variable processes e g volcanic deformation the algorithm involves removing the residual topographic component of flattened interferogram phase for each ps then unwrapping the ps phases both spatially and temporally our method finds scatterers with stable phase characteristics independent of amplitudes associated with man made objects and is applicable to areas where conventional insar fails due to complete decorrelation of the majority of scatterers yet a few stable scatterers are present

remote sensing studies of the dionysius region of the moon 1 the dionysius region is located near the western edge of mare tranquillitatis and is centered on dionysius crater which exhibits a well developed dark ray system proposed origins for these dark rays included impact melt deposits and dark primary ejecta the region also contains extensive deposits of cayley type light plains clementine multispectral images and a variety of spacecraft photography were utilized to investigate the composition and origin of geologic units in the dionysius region the portions of the dark rays for which spectral and chemical data were obtained are composed of mare debris contaminated with minor amounts of highland material both five point spectra and values of the optical maturity omat parameter indicate that the dark rays are dominated by mare basalts not glassy impact melts the high albedo rays associated with dionysius exhibit feo and tio2 values that are lower than those of the adjacent dark ray surfaces and omat values that indicate that bright ray surfaces are not fully mature the high albedo rays are bright largely because of the contrast in albedo between ray material containing highlands rich ejecta and the adjacent mare rich surfaces the mafic debris ejected by dionysius was derived from a dark iron rich unit exposed high on the inner wall of the crater this layer probably represents a mare deposit that was present at the surface of the preimpact target site with one possible exception there is no evidence for buried mare basalts associated with cayley plains in the region

fifteen years of surface deformation in western taiwan insight from sar interferometry abstract geodetically measured surface displacements are produced by a combination of underlying deformation processes acting at different spatial and temporal scales a complete history of surface measurements in an area can help discriminate contributions from tectonic hydrologic and anthropogenic processes in this study we use synthetic aperture radar sar images of the active mountain front and adjacent coastal plain of southwestern taiwan to generate time series of surface deformation from 1995 to 2001 and from 2005 to 2008 based on the insar small baseline method the insar measurements agree well with los motions estimated from continuous gps measurements of 3d displacements between 2006 and 2008 a significant range increase in line of sight los is dominated by land subsidence in the coastal area of western and southwestern taiwan subsidence rates vary with annual periods and are highly correlated with seasonal precipitation which are likely associated with groundwater recharge and withdrawal the long term deformation is dominated by long term tectonic loading in sw taiwan during the interseismic period of the earthquake cycle including elastic strain along or continuous creep on the active faults our results show the ability of insar to reveal spatiotemporal crustal deformation in western taiwan with high spatial resolution and accuracy which is potentially important for evaluating seismic hazards

land subsidence in bangkok thailand abstract land subsidence from deep well pumping has been affecting bangkok for the past 35 years its impact is particularly critical because of the flat low lying topography and the presence of a thick soft clay layer at the ground surface that augment flood risk and foundation engineering problems respectively the subsidence reached its most critical state in the early 1980s when it occurred at a rate as high as 120 mm year the rate decreased in the subsequent period but the subsidence affected area expanded following the growth of the city despite various attempts implemented to remedy the crisis groundwater pumping from the thick aquifer system underneath the city continued to increase from 1 2 million m3 day in the early 1980s to more than 2 0 million m3 day at the turn of the century piezometric levels in the main aquifer layers had been drawn down by as much as 65 m monitoring data showed a clear correlation between the subsidence and piezometric drawdown the data suggested that for 1 m3 of groundwater pumped out in bangkok plain approximately 0 10 m3 of ground loss occurred at the surface significant development has been made in numerical methods for prediction of differential settlements between building foundations caused by the piezometric drawdown in the aquifers the strict mitigation measures adopted recently comprising a pricing policy for groundwater management an expansion of tap water supply and strict enforcement of groundwater laws have resulted in a marked drop in groundwater use however the land subsidence will continue for a long while owing to the time dependent consolidation behavior of the soft clay layer and clay aquitards

imaging of lunar surface maturity the physical evolution of the lunar surface with exposure to the space environment is termed maturation and maturity is the degree to which a particular lunar soil possesses quantitative characteristics consistent with that exposure several quantitative measures or indices of maturity have been proposed and employed including the abundance of solar wind gas abundance of various types of agglutinates various measures of grain size and is feo among the changes attendant with space exposure are striking changes in the optical characteristics of soils mature lunar soils are dark red and exhibit reduced spectral contrast relative to immature soils this paper presents an optical maturity index that quantifies the spectral effects of maturation we show that this optical maturity index correlates with other maturity indices about as well as the accepted maturity indices correlate among themselves and is only weakly coupled to composition the modest correlations among maturity indices suggest important controls on individual maturity indices other than age uncorrelated variations in the rates of accumulation of individual indicators or variations in depths over which indicators are emplaced in addition to mixing these effects conspire to reduce the equivalence of maturity and duration of surface exposure optical maturity illustrates some of these effects showing that ejecta of large and small craters mature at different rates and that the interiors and ejecta of large craters exhibit systematically different optical maturities the same or analogous effects are likely to influence other maturity indices

basalt thickness in mare humorum the crater excavation method basalt thicknesses in mare basins have been determined using assumptions about the premare topography of partly buried craters and by comparison to the orientale basin differences in those assumptions have led to a factor of 4 difference in mare thickness estimates further knowledge of thickness is restricted to areas in which buried craters are present using mixing models applied to multispectral images acquired by the clementine spacecraft we have shown that craters in the mare sometimes excavate highland material from below the mare cover using such craters and assumptions about their depth of excavation we obtain independent estimates of basalt thickness our results are in agreement with the lowest of previous thickness estimates we derive a volume of 40 000 km 3 for basalts in mare humorum considerably less than the 110 000 km 3 from previous estimates we also confirm a diameter of 425 km for thc humorum multiring basin based on the clementine gridded global topography assuming an original morphology like orientale

compositional studies of the orientale humorum nectaris and crisium lunar basins we have used full resolution 250 m pixel clementine images to map the compositions of ejecta from four multiring basins on the moon orientale humorum nectaris and crisium all basins have relatively feldspathic ejecta with iron contents ranging from 2 to 6 wt feo some basins show remarkably homogeneous ejecta blankets orientale while others display distinct compositional zoning within exterior sectors of the basin crisium in some cases this zoning correlates with morphologically observed ejecta facies nectaris the iron poor composition of most basin ejecta indicates that the crust of the moon at these locations is feldspathic down to depths of at least several tens of kilometers the likely sampling depth of basin forming impacts the inner rings of all four basins display massifs and small crater floors of nearly pure anorthosite feo 1 wt virtually the only such occurrences of this rock type on the moon because basin rings are structurally emplaced topographic elements derived from depths of at least 10 20 km into the moon we postulate that basin inner rings are sampling a unique stratigraphic level in the moon and at these depths the primordial pristine anorthositic crust of the moon is largely preserved below this zone of anorthosite is the more mafic region of the lower crust probably having highland basalt composition feo 10 wt al2o3 18 22 wt the petrologic nature of lower crustal levels remains uncertain but must at least in part include members of the mafic highland suite such as norites and troctolites

a sharper view of impact craters from clementine data the ultraviolet visible camera on the clementine spacecraft obtained high spatial resolution images of the moon in five spectral channels impact craters mapped with these multispectral images show a scale of lithologic diversity that varies with crater size and target stratigraphy prominent lithologic variations feldspathic versus basaltic occur within the south wall of copernicus 93 kilometers in diameter on the scale of 1 to 2 kilometers lithologic diversity at tycho 85 kilometers in diameter is less apparent at this scale although the impact melt of these two large craters is remarkably similar in this spectral range the lunar surface within and around the smaller crater giordano bruno 22 kilometers in diameter is largely dominated by the mixing of freshly excavated material with surrounding older soils derived from a generally similar feldspathic lithology

the evolution of the lunar nectaris multiring basin abstract nectaris is an 820 km diameter multiring impact basin located on the near side of the moon the transient cavity is estimated to have been less than 90 km in depth and materials were excavated from a depth of less than 30 km about 2 km thickness of impact melt is believed to line the cavity center the impact event probably took place at about 3 98 0 03 109 years ago nectaris ejecta forms a substantial proportion of the surface materials at the apollo 16 site inter ring plains deposits were deposited after the formation of the nectaris basin the most persuasive origin for the smooth plains is one of extrusives overlain by a thin veneer of ejecta basaltic fragments within apollo 16 samples are believed to have been largely derived from nectaris a titanium rich apollo 16 mare basalt fragment has an age of 3 79 0 05 109 years but although some relatively titanium enriched basalts occur in southern nectaris titanium rich basalts are nowhere seen at the surface of the mare the earliest recognized eruptives appear to be low titanium perhaps vlt basalts found as pyroclastic materials on daguerre and in the gaudibert region the majority of the surface basalts are of intermediate composition possibly similar to apollo 12 basalts and have an age of approximately 3 6 109 years the basalt fill is estimated to have a minimum thickness of 3 km flood style eruptions appear to have been the main form of extrusion mare ridges exhibit a strong north south preferential alignment and appear to postdate basalt emplacement the lack of basin related graben in nectaris is consistent with a thick lithosphere the basin ring structure is best preserved in the southwest and least preserved in the northeast this is believed to result from horizontal variations in the crust and lithosphere thicknesses and from the influence of the preexisting fecunditatis and tranquillitatis basins the ring structure is best preserved where the lithosphere was thickest floor fractured craters within nectaris are intimately associated with the basalt fill both in terms of age and location theophilus ejecta small craters and tycho rays combined with subsidence and mare ridge development were the only modifying influences on nectaris since the termination of basalt eruptions

spatial analysis of surface deformation distribution detected by persistent scatterer interferometry in lanzhou region china persistent scatterer synthetic aperture radar interferometry ps insar is a remote sensing method that can be used to detect surface deformation which is an indicator of potential geohazards by capturing such deformations over time it is possible to obtain valuable information regarding geohazards such as landslides this study focused on the use of ps insar to investigate the distribution and causes of surface deformation in the lanzhou region of gansu province in china between 2003 and 2010 41 advanced synthetic aperture radar images were captured by the envisat satellite and analyzed using ps insar and the correlation between the observed surface deformation and topographic geologic and anthropogenic factors was derived based on a geographic information system platform it was found that the largest number and highest density of surface deformations occurred at elevations of 1486 1686 m it was also established that slope ranges of 25 30 and 35 40 are threshold values at which surface deformation changes abruptly and that slopes with north and northwest aspects are most prone to surface deformation the lithologies most susceptible to surface deformation are clay sandy soil and loess the normalized difference vegetation index indicated that surface deformation occurred most often in areas with sparse vegetation anthropogenic activities e g construction and wastewater discharge could be inferred as causal mechanisms of surface deformation comparison of the distributions of geohazards and surface deformation showed considerable consistency which proves surface deformation can induce geohazards these results could help governments improve urban planning and geohazard mitigation

a growing structure near the deformation front in sw taiwan as deduced from sar interferometry and geodetic observation 1 we apply the d insar technique to monitor the active growing structure on the tainan tableland near the deformation front in sw taiwan using ers sar images in the period of 1996 2000 interferometric processing of six sar images reveals the average slant range displacement srd to be 12 5 mm yr and it increases from the west edge of the tainan tableland and decreases across the houchiali fault the gps campaign data indicate an average horizontal movement of 12 4 mm yr in the direction of n44 w for the tainan tableland with respect to the western coastline five precise leveling surveys across the tainan tableland over two years show an uplift rate of 14 mm yr for the benchmarks on the tableland by combining the horizontal velocity of gps data and the srd of d insar we transfer the srd into vertical deformation and discuss the deformation pattern and seismic hazards in the tainan area

a new project to monitor land subsidence in the northern venice coastland italy the paper deals with the implementation of a levelling and global positioning system gps network to control land subsidence in the coastal area north of the venice lagoon about 480 km of levelling lines with 527 benchmarks 45 of which suited for differential gps measurements were established in 2004 a complete survey of the net was carried out in 2004 soon after its establishment the 2004 records have been compared with previous scattered data obtained by the use of levelling surveys dgps and sar interferometry the results show a trend in land settlement that increases from the lagoon margin to the north and jeopardize the venice coastland groundwater withdrawals for domestic agricultural and health spas uses peat oxidation of reclaimed marshlands for farming natural consolidation of the holocene deposits and tectonics of the pre quaternary basement are the causes of land subsidence in the study area since most of the area lies below the mean sea level and on account of the expected sea level rise due to global change a detailed monitoring of land displacements in the near future will be of paramount importance to plan necessary works for coastland protection

compositional variability of the serenitatis tranquillitatis region of the moon from telescopic multispectral imaging and spectroscopy abstract we present results from a combined ccd multispectral imaging and near ir spectroscopic study of a region near the border between the mare serenitatis and mare tranquillitatis lunar impact basins we have detected and spatially mapped variations in mare tio 2 abundance in the degree of spectral maturity of impact craters and their ejecta blankets and in the level of fresh highlands contamination within mare units techniques employed include color ratio images image oriented linear mixing models and spectral band analyses specific findings include the detection of relatively fresh highlands materials in the craters tacquet and sulpicius gallus and in the central peak and floor of the crater plinius the detection of low tio 2 serenitatis like mare materials in a confined region of the ejecta from the crater dawes and the determination of immaturity rather than composition as the origin of the high albedo in the rectangular deposit surrounding dawes the combination of high spatial resolution imaging and high spectral resolution spectroscopy and the use of synthesizing techniques such as mixture modeling will provide valuable tools to optimize the scientific return from telescopic galileo clementine and other future lunar data sets

mare tranquillitatis basalt emplacement history and relation to lunar samples galileo and clementine multispectral data of the mare tranquillitatis region have been analyzed to investigate the stratigraphy of basaltic units and the effects of lateral and vertical mixing processes within the mare the distribution of compositionally distinct mare units is observed to be correlated with previous uv vis ratio images although estimates of soil titanium contents are low in some areas as a result of mixing of local basalts with nonmare feldspathic materials basalt units identified by their spectral properties and spectral mixture analysis are compared with groups of apollo 11 samples defined by previous workers on the basis of age and chemistry spectral studies presented here indicate that the apollo 11 site lies at the edge of a localized western mare unit which includes the youngest and most titanium rich basalts in tranquillitatis apollo 11 high k high ti samples in southern tranquillitatis these basalts have been contaminated by a large degree of mixing with nonmare feldspathic materials nonmare materials near the apollo 11 site are attributed largely to crater rays from theophilus 100 km in diameter which is located approximately 300 km to the south a more extensive and stratigraphically older unit exposed near apollo 11 is related to the low k high ti apollo 11 samples and appears to extend as a coherent surface unit as far north as the apollo 17 site in southern serenitatis the distribution of this spectrally identified basalt unit supports petrologic and geochemical evidence for the grouping of the high ti low k apollo 11 and 17 basalt samples into the same regional volcanic events multispectral analysis of tranquillitatis deposits also identify low titanium basalts in the northeastern and southeastern portions of the basin that are older than the high ti basalts and are believed to be unsampled by apollo 11 several lines of evidence suggest that the cayley formation along the western tranquillitatis margin may indeed lie on top of an ancient mare deposit buried by imbrium basin ejecta e g a cryptomare deposit the distribution of vertically excavated feldspathic premare material within the mare provides information on the depth of the mare units and the proximity of the underlying basin topography compositional stratigraphy observed in both sets of multispectral data supports an asymmetric premare fill basin topography containing thicker basalts in the northwestern portion of the basin than previously predicted by crater flooding data

arctic ocean gravity geoid and sea ice freeboard heights from icesat and grace 1 icesat laser measurements provide a high resolution mapping of the sea ice surface of the arctic ocean which can be inverted to determine gravity anomalies and sea ice freeboard heights by a lowest level filtering scheme in this paper we use updated terrestrial gravity data from the arctic gravity project in combination with grace gravity field models to derive an improved arctic geoid model this model is then used to convert icesat measurements to sea ice freeboard heights with a coarse lowest level surface method the derived freeboard heights show a good qualitative agreement to the coverage of multi year sea ice however comparison to an airborne lidar underflight north of greenland shows that the lowest level filtering scheme may introduce a bias we finally use the icesat and grace results to derive new gravity anomalies by fourier inversion the satellite only gravity field shows all major tectonic features of the arctic ocean and has an accuracy of 6 mgal compared to recent airborne gravity data illustrating the usefulness of icesat data for gravity field determination

application of sar interferometry to a large thrust deformation the 1999 mw 7 6 chichi earthquake in central taiwan summary application of the interferometric method to four ers2 sar images acquired before and after the 1999 chichi earthquake has allowed determination of the coseismic surface displacement in the footwall area of the chelungpu fault the interferometric results revealed a relative shortening in the round trip distance between the radar antenna and the ground of the footwall side of chelungpu fault during the earthquake this shortening progressively increased from the west to the east and reaches the maximum amount of approximately 26 cm near the central segment of the chelungpu fault our interferometric results have been precisely examined using a dense gps network in the investigated area we mapped the gps coseismic measurements into the radar line of sight and implemented a forward simulation of sar interferogram from this synthesized result to control our unwrapping performance in this study these two observations are compared with a 3 d dislocation model of the fault finally a deformation analysis based on our interferometric result has indicated that a segment with irregular deformation behaviour can be distinguished in the footwall area of the chelungpu fault this segment may result from either the influence of inherited basement faults or the presence of a structural terrace that provide local opportunities for superficial deformation

remote sensing of potential lunar resources 1 near side compositional properties new telescopic ccd multispectral imaging of the lunar near side and 330 870 nm spectroscopy of selected regions are presented as aids in estimating compositional differences relevant to locating potential lunar resources such as ilmenite fetio3 and solar wind implanted 3he and h conversion of 400 560 nm ccd ratio images to weight percent tio2 using a version of the charette et al 1974 empirical relation allows construction of a new tio2 abundance map for the lunar maria accurate to 2 wt ho2 this map provides a consistent view of tio2 distribution among mature mare soils and can be used to estimate areas potentially rich in ilmenite western mare tranquillitatis exhibits the highest tio2 abundances 8 wt followed by regions near flamsteed p and in northern oceanus procellarum a 950 560 nm ccd ratio mosaic of the full moon provides estimates of relative surface maturity on local scales as defined by the degree of agglutinate production due to micrometeorite impacts since high 3he concentrations are correlated with mature ilmenite rich soils a combination of relative surface maturity maps and tio2 abundance maps may be useful for estimating 3he and possibly h distribution on local scales while dark mantle materials are also potential sources of ilmenite 3he and h their compositional differences from mare soils prevent accurate remote mapping of their tio2 abundance and relative maturity reflectance spectra relative to a more rigorously defined ms 2 standard region of dark mantle materials and high tio2 mare areas exhibit previously undocumented near uv 350 nm changes in spectral slope apparently related to compositional variations determination of the primary lunar sites for resource utilization will be dictated by the future goals and priorities of the lunar resource program

tectonic evolution of the emergent part of a volcanic ocean island lanzarote canary islands abstract a reconstruction of the structural evolution of lanzarote confirms the existence of two principal stages of construction of the island separated by a main erosional event the first pre erosional is the shield stage miocene pliocene in age which is divided in three stratigraphic groups where different formations can be distinguished using unconformities mappable over the whole area of outcrop in the second post erosional stage developed during the quaternary nine stratigraphic levels are tentatively identified and are grouped in two phases of volcanic activity shields phase and pyroclastic cones phase data from 580 photogeologic lineaments as well as field data from 204 fault planes 195 with sense of movement 273 dykes and 45 volcanic alignments are presented the tectonic style of the deformations is brittle and polyphasic strike slip faults are dominant but normal and reverse faults are also present both the so called atlantic and african directions are well developed in trends of strike slip faults and volcanic indicators at least two deformation phases can be identified from the geometrical analysis of faults and from the stress tensor calculated using lineations on fault planes the reconstructed stress field responsible for the measured deformations changed orientation during the evolution of the island of lanzarote it is suggested that a permutation between principal stress axes 1 and 3 occurred subparallel to the length of the island between the pre erosional and post erosional stages

evaluation of earthquake potential and surface deformation by differential interferometry abstract uncertainties in the length of active faults and the styles of deformation often hamper the evaluation of seismic potentials in a region in the area near chiayi city of southwestern taiwan where historically there have been many strong earthquakes complex fault and fold systems produced by regional tectonic forces and the subsequent deformation are frequently obscured by vegetation and anthropogenic effects and therefore detailed deformation information has not been available for evaluation of the seismic potential by stacking the results from differential interferometry and removing the ambiguity of interferograms using gps data we were able to retrieve surface deformation information about the area under consideration near chiayi city in our results we found that the meishan fault to the north of chiayi city extended 10 km to the west of its currently documented area and served as a geological boundary separating the northern part where sediments were thicker from the southern part of the westward extension of the meishan fault chiayi city was under active deformation by a double plunging fold with vertical uplift rate at approximately 1 cm yr frequent seismicity and active deformation allowed the tectonic stress to permute between strike slip and thrust in this area continuous folding of chiayi city and episodic large earthquakes along the meishan fault posed a serious threat of seismic hazards in this region and called for continuous monitoring of the area

coseismic deformation from the 2008 wenchuan china earthquake derived from alos palsar images abstract we analyzed alos palsar images along eight paths acquired before and after the mainshock of an earthquake in wenchuan in the sichuan province of china may 12 2008 we found entire coseismic deformation features and detected many fringes in an approximately 100 km wide region surrounding the longmen shan fault zone we found 6 7 broad elliptic fringes north of the epicenter which indicated around 70 80 cm increase in range distance between the ground and satellite this pattern corresponded to subsidence or eastward shift of ground which is often seen above the lower margin of a low angled thrust we also counted 8 9 fringes i e 90 100 cm range decrease between the fault zone and chengdu chengdu is located roughly 50 km away from the pengguan fault which is the southernmost trace of the longmen shan fault zone as this area is located on the footwall side the pattern suggested a westward shift of the earth s surface however we could not obtain high correlations due to large displacements in the about 240 km long belt along the surface faults several concentric fringes were found along the beichuan fault which is the central trace of the longmen shan fault zone this implied that the rupture process of this earthquake was complicated we also performed pixel matching to estimate offsets in the region of low correlation positive and negative range offsets larger than 2 m were found on the north and south sides of the beichuan fault respectively we observed a belt of negative range and azimuth offsets between the beichuan and pengguan faults we calculated an interferogram using a multi segment fault model with uniform slip along the beichuan and pengguan faults and estimated the slip distribution based on previous seismological studies we assumed that the southwestern part dipped toward the northwest by 33 degrees whereas the central and northeastern parts had a much steeper dip angle we found two regions of slips larger than 4 m in the southwest and central parts of the beichuan fault the pengguan segments may have much smaller slips around 1 m the southwestern segments of the beichuan fault and the entire pengguan fault had dominant thrust components whereas dextral slip prevailed in the central and northeastern segments of the beichuan fault the estimated geodetic moment was 5 87 1020nm mw 7 78

lunar iron and titanium abundance algorithms based on final processing of clementine ultraviolet visible images the clementine mission to the moon returned global imaging data collected by the ultraviolet visible uvvis camera this data set is now in a final state of calibration and a five band multispectral digital image model dim of the lunar surface will soon be available to the science community we have used observations of the lunar sample return sites and stations extracted from the final dim in conjunction with compositional information for returned lunar soils to revise our previously published algorithms for the spectral determination of the feo and tio2 content of the lunar surface the algorithms successfully normalize the effects of space weathering so that composition may be determined without regard to a surface s state of maturity these algorithms permit anyone with access to the standard archived dim to construct high spatial resolution maps of feo and tio2 abundance such maps will be of great utility in a variety of lunar geologic studies

remote sensing of potential lunar resources 2 high spatial resolution mapping of spectral reflectance ratios and implications for nearside mare tio2 content high spatial resolution maps illustrating variations in spectral reflectance 400 560 nm ratio values have been generated for the following mare regions 1 the border between southern mare serenitatis and northern mare tranquillitatis including the ms 2 standard area and apollo 17 landing site 2 central mare tranquillitatis 3 oceanus procellarum near seleucus and 4 southern oceanus procellarum around flamsteed we have also obtained 320 1000 nm reflectance spectra of several sites relative to ms 2 to facilitate scaling of the images and provide additional information on surface composition inferred tio2 abundances for these mare regions have been determined using an empirical calibration which relates the weight percent tio2 in mature mare regolith to the observed 400 560 nm ratio mare areas with high tio2 abundances are probably rich in ilmenite fetio3 a potential lunar resource the highest potential tio2 concentrations we have identified in the nearside maria occur in central mare tranquillitatis inferred tio2 contents for these areas are 9 wt and are spatially consistent with the highest tio2 regions mapped previously at lower spatial resolution we note that the morphology of surface units with high 400 560 nm ratio values increases in complexity at higher spatial resolutions new telescopic spectra of landing sites successfully reproduce the charette relation although we find that the 400 560 nm value is strongly a fimction of the sample area size the increased spectral contrast of the 400 730 nm ratio over the 400 560 nm ratio demonstrates the potential increased precision with which the 400 730 nm ratio might be used to estimate tio2 abundances comparisons have been made with previously published geologic maps lunar orbiter iv and ground based images and some possible morphologic correlations have been found between our mapped 400 560 nm ratio values and volcanic landforms such as lava flows mare domes and collapse pits

compositional gradients across mare highland contacts importance and geological implication of lateral transport observations of mixing across mare highland contacts using high resolution clementine data allow a new assessment of the relative importance of vertical versus lateral mass transport on the moon at least at mare highland contact we analyze mare highland contacts in the grimaldi orientale and fecunditatis basins and tsiolkovsky crater through image based nonlinear spectral mixture modeling of clementine ultraviolet visible uv vis light spectrometer multi spectral data the mare in these regions differ in ages but they are characterized by having simple geological contacts the symmetric distribution of mare and highland soil constituents across their geological contact indicates that lateral transport is more efficient than deep vertical transport during the formation of the observed mixing zones observations across the lunar limb with the clementine uv vis filters show that there is a stray light component of scattered light across high contrast albedo boundaries however the magnitude and spatial properties of scattered light do not significantly affect the nature of compositional boundaries determined here since repetitive meteorite bombardment governs lateral transport across the geological contacts and is a random process a stochastic model is developed to describe this lateral transport analysis of the power decay law for crater ejecta thickness indicates that the high velocity ejecta travels long distances and follows a 3 power decay law this results in an infinite variance which requires an anomalous diffusion model since a classical diffusion model would be invalid mathematical modeling supports this result where it is shown that classical diffusion produces a relatively poor fit to profiles of material abundance while the anomalous diffusion model fits the profiles adequately these results indicate that high velocity ejecta dominates the formation of the observed compositional gradients while the ejecta near the crater rim is relatively less important on the basis of these ejecta distributions and the assumption of random impact cratering we derive a relationship that can be used as an index for relative age dating of geological contacts as well as for investigating cratering rates

integrated spectral analysis of mare soils and craters applications to eastern nearside basalts abstract high spatial resolution clementine images are examined to measure the reflectance properties of small and optically immature mare craters that have sampled discrete compositional units the spectral properties of these relatively crystalline mare materials are compared to associated mature soils to determine the effects of space weathering on specific basalt types space weathering is observed to alter the optical properties of distinct lunar basalt units in a systematic manner allowing compositional distinctions to be recognized across maturity states ultraviolet visible reflectance properties of mare basalts are sensitive to titanium content but are relatively independent of maturity state and demonstrate only a slight reddening as regoliths mature to soils other compositional distinctions between basalt types are identified by differences in albedo and band strength of ferrous minerals that are maintained over a full range of maturity states immature deposits within large craters are compared to the spectral properties of well defined mare units to examine the composition of buried materials when craters excavate through the mare highland contamination is readily identified as a mixing relation between mafic and feldspathic lithologies the approach presented here provides new information on the composition and stratigraphy of several nearside mare deposits including the identification of thin low iron and very low titanium basalts in lacus somniorum and more iron rich low titanium basalts in eastern mare frigoris

tsiolkovsky crater a window into crustal processes on the lunar farside mineralogy and distribution of rock types in the tsiolkovsky region of the lunar farside are evaluated in terms of crustal stratigraphy and evolution calibrated multispectral images from five orbits of clementine data provide compositional information at a scale that allows diverse geologic features to be analyzed and compared the entire region is seen to be highly anorthositic with outcrops of relatively pure anorthosite quite common the crater itself has excavated blocks of anorthosite and noritic anorthosite from the near surface highland crust often in a mixed jumble the central peaks of tsiolkovsky which have exhumed much deeper material however are composed of relatively pure anorthosite with olivine rich zones concentrated near the ridge crests boundaries between the anorthosite and olivine rich zones are sharp but spatial relations suggest the coherent olivine rich zone is relatively thin 1 km the composition of the mare material filling tsiolkovsky is shown to be low titanium basalt smaller exposures of mare basalt occur about one crater radius from the rim the crustal structure to 25 km in this region prior to the tsiolkovsky impact appears to be top to bottom a few kilometers of anorthositic breccias comprising the megaregolith a zone of crystalline anorthosite with pockets of noritic anorthosite a zone of anorthosite devoid of iron bearing minerals and a zone of relatively pure anorthosite containing olivine rich material possibly emplaced as intrusions

compositional analyses of small lunar pyroclastic deposits using clementine multispectral data clementine ultraviolet visible uvvis data are used to examine the compositions of 18 pyroclastic deposits 15 small three large at 13 sites on the moon compositional variations among pyroclastic deposits largely result from differing amounts of new basaltic or juvenile material and reworked local material entrained in their ejecta upon eruption characterization of pyroclastic deposit compositions allows us to understand the mechanisms of lunar explosive volcanism evidence for compositional differences between small pyroclastic deposits at a single site is observed at atlas crater at all sites compositional variation among the small pyroclastic deposits is consistent with earlier classification based on earth based spectra three compositional groups can be observed and the trend of increasing mafic absorption band strength from group 1 to group 2 to group 3 is noted as redefined here group 1 deposits include those of alphonsus west alphonsus southeast alphonsus northeast 2 atlas south cruger franklin grimaldi lavoisier oppenheimer orientale and riccioli group 1 deposits resemble lunar highlands with weak mafic bands and relatively high uv vis ratios group 2 deposits include those of alphonsus northeast 1 atlas north eastern frigoris east and west and aristarchus plateau group 2 deposits are similar to mature lunar maria with moderate mafic band depths and intermediate uv vis ratios the single group 3 deposit j herschel has a relatively strong mafic band and a low uv vis ratio and olivine is a likely juvenile component two of the deposits in these groups orientale and aristarchus are large pyroclastic deposits the third large pyroclastic deposit apollo 17 taurus littrow has a very weak mafic band and a high uv vis ratio and it does not belong to any of the compositional groups for small pyroclastic deposits the observed compositional variations indicate that highland and mare materials are also present in many large and small pyroclastic deposits and they suggest that volcanic glasses or spheres may not be dominant juvenile components in all large pyroclastic deposits

the mafic component of the lunar crust constraints on the crustal abundance of mantle and intrusive rock and the mineralogy of lunar anorthosites most models of early lunar evolution predict that the anorthositic highlands crust is the result of plagioclase flotation on a magma ocean however the lunar highlands crust typically contains 4 wt feo and so is more mafic than the strict definition of the anorthosites thought to comprise it we used new clementine based mineral maps of the moon as inputs to a series of mixing models that calculate the abundance and distribution of major highland rock types and shed light on three possible sources of excess mafic material in the lunar highlands mafic 15 vol mafic minerals anorthosites post magma ocean igneous activity and mafic basin ejecta mixing models that feature pure anorthosites like the purest anorthosite pan described by ohtake et al 2009 and pieters et al 2009 are most compatible with the data they allow us to place an upper limit of 10 20 vol mantle material that could be mixed with the primary highlands crust the upper limit on mantle material indicated by the mixing models is significantly lower than the 30 40 vol mantle material expected from simple geometric calculations of the major lunar basins excavation cavities based on an excavation cavity depth diameter ratio of 1 10 this discrepancy allows us to conclude that the excavation cavities of the three largest lunar basins may have been significantly shallower than those of the smaller basins our results are consistent with excavation cavity depth diameter ratios for these largest basins in the range of 0 035 to 0 06 which agrees with previous gravity measurements by wieczorek and phillips 1999

understanding the subsidence process of a quaternary plain by combining geological and hydrogeological modelling with satellite insar data the acque albule plain case study abstract this paper focuses on a multidisciplinary study carried out in an urban area affected by subsidence and related structural damages the study area is located about 20 km east of rome italy and is characterised by relevant groundwater exploitation for various purposes as well as by the presence of compressible soils immediately below the ground level extensive processing at different scales of sar satellite images ers and envisat provided by esa in the frame of a cat 1 project by means of a dinsar technique was performed the time histories of ground displacements have been analysed in combination with a detailed geological setting of the study area and with the hydrogeological changes occurred in the last decades as the response to the anthropic stress based on a large piezometric dataset this comprehensive dataset allowed us to describe the space and time distributions of the subsidence process the spatial pattern and deformation rate change is attributed to the following causes i the changes in the groundwater levels due to the intensification of mine exploitation requiring dewatering operations and ii the distribution and thickness of recent compressible deposits specifically it is derived that the groundwater level variations drive the timing of subsidence triggering over the area whereas the local geological conditions control the magnitude of the deformation process

remote sensing of lunar pyroclastic mantling deposits abstract mantling deposits on the moon are considered to be pyroclastic units emplaced on the lunar surface as a result of explosive fire fountaining these pyroclastic units are characterized as having low albedos having smooth fine textured surfaces and consisting in part of homogeneous febearing volcanic glass and partially crystallized spheres mantling units exhibit low returns on depolarized 3 8 cm radar maps indicating an absence of surface scatterers in the 1 to 50 cm size range a number of reflectance spectra from several regional pyroclastic deposits are presented for the first time these data support a previous interpretation that mantling units have a unique spectral signature which is indicative of the presence of a significant fe bearing volcanic glass component the rima bode region is discussed as an example of an area in which several types of remote sensing data including 3 8 cm radar spectral reflectance and multispectral vidicon data were used to reconstruct the geologic events surrounding the emplacement of a regional pyroclastic mantling deposit the recognition of numerous varieties of volcanic glass samples especially relatively high albedo e g green yellow glasses suggests the existence of additional unrecognized mantling deposits with albedos higher than those studied to date on the basis of the remote sensing data summarized and presented five new areas have been identified which may represent higher albedo regional pyroclastic deposits

nonlinear spectral mixture modeling of lunar multispectral data implications for lateral transport linear and nonlinear spectral mixture models applied to clementine multispectral images of the moon result in roughly similar spatial distributions of end member abundances however there are important differences in the absolute values of the predicted abundances the magnitude of these differences and the implications for understanding geological processes are investigated across a geologic contact between mare and highland in the grimaldi basin on the western nearside of the moon vertical and lateral mass transport due to impact cratering has redistributed mare and highland materials across the contract creating a gradient in composition solutions to linear and nonlinear spectral mixture models for identical spectral end members of mature mare mature highland and fresh crater materials are compared across this simple geologic contact in the grimaldi basin formal estimates of uncertainty in the calculated fractions of the end members are 1 profiles of mare abundance across the contact are extracted and compared quantitatively profiles from the linear mixture models indicate that the geologic contact has an average mare abundance of 60 and the compositional boundary is asymmetric with more mare transported onto the highland side of the contact than highland onto the mare side of the contact in contrast the nonlinear abundance profiles indicate that the geologic contact has an average mare abundance of 50 and the compositional boundary is remarkably symmetric given the expectation that materials will be intimately mixed on the surface of the moon and that the asymmetries implied by the linear model are not consistent with our understanding of lunar surface processes the non linear spectral mixture model is preferred and should be applied whenever quantitative abundance information is required the remarkable symmetry in the compositional gradients across this contact indicates that lateral mass transport dominates over vertical transport at this boundary

remote sensing studies of the terrain northwest of humorum basin we have used near infrared reflectance spectra and earth based radar data to investigate the composition and origin of the various geologic units northwest of humorum basin as well as the stratigraphy of the humorum pre impact target site the results of our spectral analysis indicate that at least a portion of the inner mare bounding ring is composed of pure anorthosite other highlands units in the region are dominated by noritic anorthosite the anorthosites on the inner ring may have been derived from a layer of anorthosite that exists at depth beneath a more pyroxene rich unit both gassendi g and f craters expose mare material from beneath a highlands rich surface unit that was emplaced as a result of the letronne gassendi and other impact events this ancient basalt unit was emplaced after the formation of humorum basin but prior to the orientale impact

surviving the heavy bombardment ancient material at the surface of south pole aitken basin 1 the oldest deepest and largest basin recognized on the lunar surface is the south pole aitken spa basin in the time since its formation several processes have modified the original interior of the basin including the introduction of foreign material by impact basins during the period of heavy bombardment these later basins redistributed material ballistically across the lunar surface forming a mixed and crushed zone on the scale of about one kilometer deep models of crater excavation ejected material transport and mixing during emplacement are used to estimate the amount of foreign material from each basin event introduced into spa and the degree to which that material mixes with the surface of the interior of spa we varied the size of the transient craters for all basins the degree of mixing between foreign and local material and the number of basins considered in our evaluation our modeling results indicate that materials derived from the original spa melt breccia comprise at least 15 of the present regolith the most realistic combinations of model parameters predict a spa melt breccia component that ranges from 50 80 of the current surface regolith the compositional character of the spa interior has apparently not been obliterated by aeons of subsequent basin forming events

a comparative study of iron abundance estimation methods application to the western nearside of the moon abstract the feo weight percentage wt abundance of the moon s western nearside 55 s 55 n and 5 e 40 w is estimated using data from the infrared spectrometer 2 sir 2 and the moon mineralogy mapper m3 in this study we modified an feo abundance estimation algorithm bhatt m mall u bugiolacchi r mckenna lawlor s banaszkiewicz m nathues a ullaland k 2012 icarus 220 51 64 which relies exclusively on the 2 m absorption band parameters the modified feo abundance estimation algorithm and the regression based elemental abundance estimation algorithm wohler c grumpe a berezhnoy a bhatt m u mall u 2014 icarus 235 86 122 which is based on the 1 m and 2 m absorption band parameters is applied to the m3 data we have compared results obtained from these two modified algorithms with a previously published clementine s feo wt map lucey p g blewett d t jolliff b l 2000 j geophys res 105 20297 20306 the effects of topography and space weathering on feo wt estimates have been successfully minimized using the modified algorithm based on the 2 m absorption band parameters thus this algorithm can be successfully applied at middle to high latitudes furthermore a correction for tio2 is applied to the feo abundance estimation algorithm based on the 2 m absorption band parameters using the m3 data our comparative study shows a good correspondence between the three algorithms discussed there are two locations the crater tycho and the region around rima bode which show major discrepancies our modified algorithm based on the 2 m absorption parameters predicts 3 4 wt less feo for the ray system of tycho than for the surrounding region the average iron abundance for the lunar highlands is about 6 wt and for the mare regions is about 16 wt using the regression based elemental abundance estimation algorithm and the algorithm based on the 2 m absorption parameters this result is consistent with the previous analysis using lunar prospector gamma ray spectrometer data sets the feo wt is in the range 20 24 wt for the high ti basalts using both the modified iron abundance estimation and the regression based elemental abundance estimation algorithms

galileo imaging observations of lunar maria and related deposits the galileo spacecraft imaged parts of the western limb and far side of the moon in december 1990 ratios of 0 41 0 56 gin filter images from the solid state hnaging ssi experiment provided information on the titanium content of mare deposits ratios of the 0 76 0 99 gm images indicated 1 gin absorptions associated with fe 2 in mafic minerals mare ages were derived froin crater statistics obtained from lunar orbiter images results on mare coinpositions in western oceanus procellarum and the humorurn basin are consistent with previous earth based observations thus providing confidence in the use of galileo data to extract compositional information mare units in the grimaldi and riccioli basins range in age froin 3 25 to 3 48 ga and consist of medium to medium high titanium 4 to 7 tio2 content lavas the schiller zucchius basin shows a higher 0 76 0 99 gm ratio than the surrounding highlands indicating a potentially higher mafic mineral content consistent with previous interpretations that the area includes mare deposits blanketed by highland ejecta and light plains materials the oldest mare materials in the orientale basin occur in south central mare orientale and are 3 7 ga old youngest mare materials are in lacus autumni and are 2 85 ga old these units are medium to medium high titanium 4 to 7 tio2 basalts thus volcanism was active in orientale for 0 85 ca but lavas were relatively constant in composition galileo data suggest that mendel rydberg mare is similar to mare orientale cryptomare are present as well thus the mare lavas on the western limb and far side to 178oe are remarkably uniform in coinposition being generally of medium to medium high titanium content and having relatively low 0 76 0 99 gin ratios this region of the moon is between two postulated large impact structures the procellarum and the south pole aitken basins and may have a relatively thick crust in areas underlain by an inferred thinner crust i e zones within large basins as at apollo titanium content is often higher however no mare deposits with titanium abundances approaching those of the high titanium 9 to 14 tio2 apollo 11 and 17 basalts nor of the high titanium regions of central oceanus procellarum are seen on the western limb or eastern far side light plains deposits are generally indistinct froin the surrounding highlands in the ssi data and are inferred to be derived primarily from the same material that forins the highlands some of the light plains are too young to be related to basin forming impacts suggesting possible volcanic origin dark mantle deposit compositions derived from ssi data are consistent with earth based observations of similar near side deposits and are interpreted to be pyroclastic materials however the modernitc albedo and 1 gin absorption of the dark mantle deposit on the southwest margin of the orientale basin suggest it is a local pyroclastic deposit contaminated with underlying highland materials from the orientale impact

end member identification and spectral mixture analysis of crism hyperspectral data a case study on southwest melas chasma mars we present spectral unmixing results over the southwest melas chasma region where a variety of hydrated minerals were identified we use the disort radiative transfer model to simultaneously model mars atmospheric gases aerosols and surface scattering and retrieve the single scattering albedos ssas modeled by the hapke bidirectional scattering function from crism data we employ a spectral unmixing algorithm to quantitatively analyze the mineral abundances by modeling the atmospherically corrected crism ssas using a non negative least squares nnls linear deconvolution algorithm to build the spectral library used for spectral unmixing we use the factor analysis and target transformation fatt technique to recover spectral end members within the crism scenes we investigate several distinct geologic units including an interbedded poly and monohydrated sulfate unit interbedded unit 1 and an interbedded phyllosilicate sulfate unit interbedded unit 2 our spectral unmixing results indicate that polyhydrated sulfates in the interbedded unit 1 have a much lower abundance 10 than that of the surrounding unit 20 and thus may have been partially dehydrated into kieserite to form the interbedded strata supporting a two staged precipitation dehydration formation hypothesis in the interbedded unit 2 phyllosilicates have an abundance of 40 and are interbedded with 20 sulfates the results in combination with thermodynamic calculations performed previously suggest that the interbedded phyllosilicates and sulfates likely formed through coupled basalt weathering and evaporation the methodology developed in this study provides a powerful tool to derive the mineral abundances aiming to better constrain the formation processes of minerals and past aqueous environment on mars

fault creep along the southern san andreas from interferometric synthetic aperture radar permanent scatterers and stacking 1 interferometric synthetic aperture radar insar provides a practical means of mapping creep along major strike slip faults the small amplitude of the creep signal 10 mm yr combined with its short wavelength makes it difficult to extract from long time span interferograms especially in agricultural or heavily vegetated areas we utilize two approaches to extract the fault creep signal from 37 ers sar images along the southern san andreas fault first amplitude stacking is utilized to identify permanent scatterers which are then used to weight the interferogram prior to spatial filtering this weighting improves correlation and also provides a mask for poorly correlated areas second the unwrapped phase is stacked to reduce tropospheric and other short wavelength noise this combined processing enables us to recover the near field 200 m slip signal across the fault due to shallow creep displacement maps from 60 interferograms reveal a diffuse secular strain buildup punctuated by localized interseismic creep of 4 6 mm yr line of sight los 12 18 mm yr horizontal with the exception of durmid hill this entire segment of the southern san andreas experienced right lateral triggered slip of up to 10 cm during the 3 5 year period spanning the 1992 landers earthquake the deformation change following the 1999 hector mine earthquake was much smaller 1 cm and broader than for the landers event profiles across the fault during the interseismic phase show peak to trough amplitude ranging from 15 to 25 mm yr horizontal component and the minimum misfit models show a range of creeping locking depth values that fit the data

transient deformation induced by groundwater change in taipei metropolitan area revealed by high resolution x band sar interferometry abstract we present precise deformation velocity maps for the two year period from september 2011 to july 2013 of the northern taiwan area taipei by using persistent scatterer interferometry psi technique for processing 18 high resolution x band synthetic aperture radar sar images archived from cosmo skymed csk constellation according to the result the highest subsidence rates are found in luzou and wuku area in which the rate is about 15 mm yr and 10 mm yr respectively in the whole dataset however dramatic change from serve subsidence to uplift in surface deformation was revealed in the taipei basin in two different time spans 2011 09 2012 09 and 2012 09 2013 07 this result shows good agreement with robust continuous gps measurement and precise leveling survey data across the central taipei basin moreover it also represents high correlation with groundwater table from 8 well data in the taipei basin the storativity is roughly constant across most of the aquifer with values between 0 5 10 4 and 1 6 10 3 in jingmei formation and 0 8 10 4 and 1 4 10 3 in wuku formation this high correlation indicated that one meter groundwater level change could induce about 9 and 16 mm surface deformation change in luzou and wuku area respectively which is about eight times faster the long term tectonic deformation rate in this area thus to access the activity of the shanchiao fault it is important to discriminate tectonic movement from anthropogenic or seasonal effect in the taipei basin to better understand the geohazards and mitigation in the taipei metropolitan area