initial observations of lunar impact melts and ejecta flows with the mini rf radar 1 the mini rf radar on the lunar reconnaissance orbiter spacecraft has revealed a great variety of crater ejecta flow and impact melt deposits some of which were not observed in prior radar imaging the craters tycho and glushko have long melt flows that exhibit variations in radar backscatter and circular polarization ratio along the flow comparison with optical imaging reveals that these changes are caused by features commonly seen in terrestrial lava flows such as rafted plates pressure ridges and ponding small 20 km sized craters also show a large variety of deposits including melt flows and ponds two craters have flow features that may be ejecta flows caused by entrained debris flowing across the surface rather than by melted rock the circular polarization ratios cprs of the impact melt flows are typically very high even ponded areas have cpr values between 0 7 and 1 0 this high cpr suggests that deposits that appear smooth in optical imagery may be rough at centimeter and decimeter scales in some places ponds and flows are visible with no easily discernable source crater these melt deposits may have come from oblique impacts that are capable of ejecting melted material farther downrange they may also be associated with older nearby craters that no longer have a radar bright proximal ejecta blanket the observed morphology of the lunar crater flows has implications for similar features observed on venus in particular changes in backscatter along many of the ejecta flows are probably caused by features typical of lava flows

upper mantle beneath foothills of the western himalaya subducted lithospheric slab or a keel of the indian shield summary the fate of the mantle lithosphere of the indian plate in the india eurasia collision zone is not well understood tomographic studies reveal high p velocity in the uppermost mantle to the south of the western himalaya and these high velocities are sometimes interpreted as an image of subducting indian lithosphere we suggest that these high velocities are unrelated to the ongoing subduction but correspond to a near horizontal mantle keel of the indian shield in the south of the indian shield upper mantle velocities are anomalously low and relatively high velocities may signify a recovery of the normal shield structure in the north our analysis is based on the recordings of seismograph station nil in the foothills of the western himalaya the t component of the p receiver functions is weak relative to the q component which is indicative of a subhorizontally layered structure joint inversion of the p and s receiver functions favours high uppermost mantle velocities typical of the lithosphere of archean cratons the arrival of the ps converted phase from 410 km discontinuity at nil is 2 2 s earlier than in iasp91 global model this can be an effect of remnants of tethys subduction in the mantle transition zone and of high velocities in the keel of the indian shield joint inversion of sks particle motions and p receiver functions reveals a change in the fast direction of seismic azimuthal anisotropy from 60 at 80 160 km depths to 150 at 160 220 km the fast direction in the lower layer is parallel to the trend of the himalaya the change of deformation regimes at a depth of 160 km suggests that this is the base of the lithosphere of the indian shield a similar boundary was found with similar techniques in central europe and the tien shan region but the base of the lithosphere in these regions is relatively shallow in agreement with the higher upper mantle temperatures the ongoing continental collision is expressed in crustal structure the crust beneath nil is very thick 58 2 km and the s velocity in the intermediate and lower crust is around 4 0 km s 1 this anomalously large velocity and thickness can be explained by scraping off the lower crust when the indian lithosphere underthrusts the himalaya

new results and implications for lunar crustal iron distribution using sensor data fusion techniques remote measurements of the moon have provided iron maps and thus essential constraints for models of lunar crustal formation and mare basalt petrogenesis a bulk crustal iron map was produced for the equatorial region from apollo gamma ray agr spectrometer measurements and a global iron variation map from recent clementine spectral reflectance csr measurements both iron maps show bimodal distribution but have significantly different peak values and variations in this paper csr data have been recalibrated to pyroxene in lunar landing site soils a residual iron map is derived from the difference between agr bulk and recalibrated csr pyroxene iron abundances the most likely interpretation is that the residual represents ferrous iron in olivine this residual iron is anticorrelated to basin age with older basins containing less olivine suggesting segregation of basin basalt sources from a progressively fractionating underlying source region at the time of basin formation results presented here provide a quantitative basis for 1 establishing the relationship between direct geochemical gamma ray x ray and mineralogical near ir remote sensing data sets using sensor data fusion techniques to allow 2 simultaneous determination of elemental and mineralogical component distribution on remote targets and 3 meaningful interpretation of orbital and ground based spectral reflectance measurements when calibrated data from the lunar prospector mission are available mapping of bulk crustal iron and iron bearing soil components will be possible for the entire moon similar analyses for data from the near earth asteroid rendezvous near mission to asteroid 433 eros will constrain models of asteroid formation

stratification of anisotropy in the pacific upper mantle 1 on the basis of the use of broadband 25 150 s rayleigh wave group speeds to estimate the 2 component of azimuthal anisotropy we present evidence for a stratification of anisotropy in the uppermost mantle at large scales across the pacific basin we confirm previous surface wave studies that established that the fast axis directions of azimuthal anisotropy for intermediate and long period rayleigh waves approximately align with present day plate motions at shorter periods 25 50 s however fast axes align nearer to the paleospreading or fossil spreading direction which differs from present day plate motion in the old pacific these observations as well as observations of the age dependence of the amplitude of azimuthal anisotropy imply that azimuthal anisotropy in the pacific upper lithosphere 100 km depth is fixed or fossilized on average reflecting the strain conditions extant during the early evolution of the lithosphere rather than the current ambient flow direction in the deeper lithosphere and asthenosphere anisotropic fast axis directions align nearer to present day plate motions apparently having reoriented to conform to the current conditions of mantle flow the mechanism of anisotropy stratification remains unclear but observations are consistent with the anisotropy of the shallow lithosphere being fixed because the shear flows that can produce dislocation creep and a change in anisotropy will occur at increasing depths as the plate ages

characterization of previously unidentified lunar pyroclastic deposits using lunar reconnaissance orbiter camera data 1 we used a lunar reconnaissance orbiter camera lroc global monochrome wide angle camera wac mosaic to conduct a survey of the moon to search for previously unidentified pyroclastic deposits promising locations were examined in detail using lroc multispectral wac mosaics high resolution lroc narrow angle camera nac images and clementine multispectral ultraviolet visible or uvvis data out of 47 potential deposits chosen for closer examination 12 were selected as probable newly identified pyroclastic deposits potential pyroclastic deposits were generally found in settings similar to previously identified deposits including areas within or near mare deposits adjacent to highlands within floor fractured craters and along fissures in mare deposits however a significant new finding is the discovery of localized pyroclastic deposits within floor fractured craters anderson e and f on the lunar farside isolated from other known similar deposits our search confirms that most major regional and localized low albedo pyroclastic deposits have been identified on the moon down to 100 m pix resolution and that additional newly identified deposits are likely to be either isolated small deposits or additional portions of discontinuous patchy deposits

the miniature radio frequency instrument s mini rf global observations of earth s moon abstract radar provides a unique means to analyze the surface and subsurface physical properties of geologic deposits including their wavelength scale roughness the relative depth of the deposits and some limited compositional information the nasa lunar reconnaissance orbiter s lro miniature radio frequency mini rf instrument has enabled these analyses on the moon at a global scale mini rf has accumulated 67 coverage of the lunar surface in s band 12 6 cm radar with a resolution of 30 m pixel here we present new mini rf global orthorectified uncontrolled s band maps of the moon and use them for analysis of lunar surface physical properties reported here are readily apparent global and regional scale differences in lunar surface physical properties that suggest three distinct terranes namely a 1 nearside radar dark region 2 orientale basin and continuous ejecta and the 3 highlands radar bright region integrating these observations with new data from lro s diviner radiometer rock abundance maps as well clementine and lunar prospector derived compositional values show multiple distinct lunar surface terranes and sub terranes based upon both physical and compositional surface properties previous geochemical investigations of the moon suggested its crust is best divided into three to four basic crustal provinces or terranes feldspathic highlands terrane an and outer procellarum kreep terrane and south pole aitken terrane that are distinct from one another however integration of these geochemical data sets with new geophysical data sets allows us to refine these terranes the result shows a more complex view of these same crustal provinces and provides valuable scientific and hazard perspectives for future targeted human and robotic exploration

the construction of a simple portable electromagnetic vibrator from commercially available components since its introduction in the late 1950s hydraulic vibrators have become the dominant source for land seismic surveys the hydraulic vibrators typically used for commer cial land seismic acquisition however are large costly to operate and expensive to purchase this inhibits their use for small scale and short duration surveys as well as vibroseis research in this paper we describe in detail the construction of a portable vibrator from commercially available components for a cost of less than us2 000 data shows that the vibrator is able to successfully transmit sweeps from 15 to 180 hz with different spectral contents the vibrator produces a stronger signal than a sledge hammer and we estimate its output to be around 1 kn the frequency content of the data was concentrated at lower frequencies 100 hz and the ground roll was far more energetic than that produced using a sledgehammer

three component seismic land streamer study of an esker architecture through s and surface wave imaging we deployed a newly developed 3c microelectromechanical system based seismic land streamer over porous glacial sediments to delineate water table and bedrock in southwestern finland the seismic so

the nature of lunar volatiles as revealed by mini rf observations of the lcross impact site 1 on 9 october 2009 the lunar crater observation and sensing satellite lcross impacted cabeus crater located near the south pole of the moon prior to that impact the mini rf instruments on isro s chandrayaan 1 and nasa s lunar reconnaissance orbiter lro obtained s band 12 6 cm synthetic aperture radar images of the impact site at 150 and 30 m resolution respectively these observations show that the floor of cabeus has a circular polarization ratio cpr comparable to or less than the average of nearby terrain in the southern lunar highlands furthermore 2 of the pixels in cabeus crater have cpr values greater than unity this observation is not consistent with the presence of thick deposits of nearly pure water ice within a few meters of the lunar surface but it does not rule out the presence of small 10 cm discrete pieces of ice mixed in with the regolith in addition mini rf on lro acquired a postimpact s band image of the region surrounding the lcross impact site providing important geologic context for the site registering the lro image to a near infrared nir image taken by the lcross shepherding spacecraft we find that the impactor landed in the ray of a fresh radar bright 1 km crater however the difference between preimpact and postimpact images is not above the speckle noise this implies that the size of the lcross impact crater is less than mini rf s resolution 30 m and or that the impact did not excavate more decimeter size blocks than were already present at the impact site

integration of sh seismic reflection and love wave dispersion data for shear wave velocity determination over quick clays quick clay is a water saturated formation originally formed through flocculation and deposition in a marine to brackish environment it is subsequently leached to low salinity by freshwater flow if its strength decreases then the flocculated structure collapses leading to landslides of varying destructiveness leaching can result in a reduction of the undisturbed shear strength of these clays and suggestions exist that a reduction in shear wave velocities is also possible integration of sh seismic reflection and love wave dispersion data was undertaken in an area near the gota river in southwest sweden to evaluate the potential of shear wave velocity imaging for detecting quick clays seismic reflection processing evidenced several geologically interesting interfaces related to the probable presence of quick clays locally confirmed by boreholes and sand gravelly layers strongly contributing to water circulation within them dispersion data were extracted with a gaussian windowing approach and inverted with a laterally constrained inversion using a priori information from the seismic reflection imaging the inversion of dispersion curves has evidenced the presence of a low velocity layer lvl with a velocity reduction of ca 30 per cent probably associable to quick clays this velocity reduction is enough to produce detectable phase velocity differences in the field data and to achieve a better velocity resolution if compared to reflection seismic velocity analyses the proposed approach has the potential of a comprehensive determination of the shear wave velocity distribution in the shallow subsurface a sensitivity analysis of love wave dispersion data is also presented underlining that despite limited dispersion of the data set and the velocity reducing effect of quick clay leaching the proposed interpretation procedure arises as a valuable approach in quick clay and other lvl identification

modeling polarimetric radar scattering from the lunar surface study on the effect of physical properties of the regolith layer 1 a theoretical model for radar scattering from the lunar regolith using the vector radiative transfer theory for random media has been developed in order to aid in the interpretation of mini sar data from the chandrayaan 1 and lunar reconnaissance orbiter missions the lunar regolith is represented as a homogeneous fine grained layer with rough upper and lower parallel interfaces that possesses embedded inclusions with a different dielectric constant our model considers five scattering mechanisms in the regolith layer diffuse scattering from both the surface and subsurface volume scattering from buried inclusions and the interactions of scattering between buried inclusions and the rough interfaces both the lunar surface and subsurface multiple scattering between buried inclusions and coherent backscatter opposite effect are not considered in the current model the modeled radar scattering coefficients are validated using numerical finite difference time domain simulations and are compared with incident angle averaged earth based radar observations of the moon both polarized and depolarized radar backscattering coefficients and the circular polarization ratio cpr are calculated as a function of incidence angle regolith thickness surface and subsurface roughness surface slope abundance and shape of buried rocks and the feo tio2 content of the regolith simulation results show that the polarized opposite sense radar echo strength at s and x bands is mostly dominated by scattering from the rough surface and buried rocks while the depolarized same sense radar echo strength is dominated by scattering from buried rocks or ice inclusions finally to explore the expected polarimetric signature of ice in the polar permanently shadowed areas four parametric regolith models are considered and the possibility of detecting diffuse ice inclusions by the cpr is addressed our study suggests that detection of ice inclusions at the lunar poles using solely the cpr will be difficult given the small dielectric contrast between the regolith and ice

integration of multicomponent time lapse processing and interpretation focus on shear wave splitting analysis multicomponent seismic processing and interpretation have become disconnected in industry practice hindering the ability to extract meaningful reservoir characterization conclusions integrating seismic processing with the final interpretation goals elevates the overall characterization that can be performed and drives advancements in processing algorithms the focus of this study is on converted waves because of their high sensitivity to the azimuthal anisotropy caused by preferential fractures and differential stress and ultimately because they provide a method of correlating hydraulic stimulation success to the enhanced permeability pathways created in the hydraulic completion process

a compositional study of the aristarchus region of the moon using near infrared reflectance spectroscopy newly obtained near infrared reflectance spectra for features on or near the aristarchus plateau demonstrate the diversity of compositions in the region highland units are of three probable compositions a feldspar and clinopyroxene assemblage a probable clinopyroxene olivine and possibly feldspar assemblage and an assemblage composed of olivine or olivine and feldspar the feldspar clinopyroxene assemblage is tentatively correlated with the major th anomaly centered on aristarchus crater the regional pyroclastic deposits on the plateau are composed of greater than 90 fe2 bearing glass the aristarchus cratering event fully penetrated any mare or pyroclastics in the target evidence for mare related material is found in the ejecta on the mare side of the mare plateau contact

compton belkovich volcanic complex cbvc an ash flow caldera on the moon abstract volcanic calderas are found on earth mars venus and io and are rare but unique volcanic structures in the solar system compton belkovich volcanic complex cbvc 60 5 n 99 5 e on the far side of the moon is a unique non mare feature due to its evolved lithology regional tectonic setting its location being near the north pole far from the procellarum kreep terrane pkt and its recent association with endogenic water high resolution remote sensing observations of several structural features at cbvc such as ring faults radial faults fractures manifested by various morphological features such as domes of varied sizes and shapes and pyroclastic ash flows characterize it to be a volcanic caldera the loading of humboldtianum basin with basalts and subsequent development of extensional structures outside it along with high thorium anomaly and resulting silicic volcanism at cbvc producing central collapsed caldera could be considered as an analogy to silicic calderas on earth formed in extensional tectonic regime even though the tectonic processes involved in these two cases are entirely different the former being impact related whereas the latter involves rifting or hotspot related activities associated with extensional plate tectonics presence of high reflectance feature and its extension to the east southeast of the topographic expression and its relation with pyroclastic dispersal have been supported by radar based mini rf observations and high resolution lroc nac imagery it suggests the presence of a late stage fine pyroclastic layer within the cbvc region the diverse volcanic features that exist at the studied site indicate a series of deformation and eruption events associated with silicic magmatism and thus cbvc could be considered as an ash flow caldera on the moon here we present a detailed appraisal of various volcanic and structural features detected at cbvc through high resolution optical as well as radar observations based on the previous and present studies an evolutionary model of the area has been proposed and the petrological implications of silicic magmatic activity its manifestation evolution and association with endogenic water have been discussed

focused 70 cm wavelength radar mapping of the moon we describe new 70 cm wavelength radar images of the lunar near side and limb regions obtained via a synthetic aperture radar patch focusing reduction technique the data are obtained by transmitting a circularly polarized pulsed waveform from the arecibo telescope in puerto rico and receiving the echo in both senses of circular polarization with the robert c byrd green bank telescope in west virginia the resultant images in both polarizations have a spatial resolution as fine as 320 m 450 m near the lunar limb the patch focusing technique is a computationally efficient method for compensating for range migration and doppler azimuth smearing over long coherence times i e 983 s which is needed to achieve the required doppler resolution three to nine looks are averaged for speckle reduction and to improve the signal to noise ratio at this long wavelength the radar signal penetrates up to several tens of meters into the dry lunar surface materials thus revealing details of the bulk loss properties and decimeter scale rock abundance not evident in multispectral and other remote sensing data application of the new radar images to the analysis of basalt flow complexes in mare serenitatis shows that the long wavelength radar data are sensitive to differences in both flow age and composition and may be particularly useful for studies of smaller deposits that do not have robust crater statistics the new 70 cm lunar radar data are archived at the national aeronautics and space administration planetary data system

volcanic and impact deposits of the moon s aristarchus plateau a new view from earth based radar images lunar pyroclastic deposits reflect an explosive stage of the basaltic volcanism that filled impact basins across the nearside these fine grained mantling layers are of interest for their association with early mare volcanic processes and as possible sources of volatiles and other species for lunar outposts we present earth based radar images at 12 6 and 70 cm wavelengths of the pyroclastic deposit that blankets the aristarchus plateau the 70 cm data reveal the outlines of a lava flow complex that covers a significant portion of the plateau and appears to have formed by spillover of magma from the large sinuous rille vallis schroteri the pyroclastics mantling these flows are heavily contaminated with rocks 10 cm and larger in diameter the 12 6 cm data confirm that other areas are mantled by 20 m or less of material and that there are numerous patches of 2 cm and larger rocks associated with ejecta from aristarchus crater some of the radar detected rocky debris is within the mantling material and is not evident in visible wavelength images the radar data identify thick rock poor areas of the pyroclastic deposit best suited for resource exploitation

young lunar volcanic features thermophysical properties and formation abstract irregular mare patches imps are small volcanic features on the lunar nearside with young model ages several formation mechanisms have been proposed including caldera collapse explosive outgassing lava flow inflation pyroclastic eruption and regolith drainage we present new observations of the four largest imps sosigenes ina cauchy 5 and maskelyne using the lunar reconnaissance orbiter lro diviner lunar radiometer diviner and evaluate the formation hypotheses in the context of both previous results and the results presented here we find that the imps have a rock abundance slightly higher than their surrounding terrain comparison of the diviner data with thermal models excludes the possibility of extensive competent rocks within 15 cm of the surface at the imps we also derive the thermal inertia at the four largest imps three appear to have thermal inertias slightly higher than typical regolith due to alteration by nearby craters or mass wasting from surrounding steep slopes but ina has a thermal inertia lower than the surrounding terrain in particular the largest smooth mound in ina is the area with the lowest thermal inertia suggesting that the material on the mound is less consolidated than typical regolith and or contains fewer small rocks

initial results for the north pole of the moon from mini sar chandrayaan 1 mission 1 we present new polarimetric radar data for the surface of the north pole of the moon acquired with the mini sar experiment onboard india s chandrayaan 1 spacecraft between mid february and mid april 2009 mini sar mapped more than 95 of the areas polewards of 80 latitude at a resolution of 150 meters the north polar region displays backscatter properties typical for the moon with circular polarization ratio cpr values in the range of 0 1 0 3 increasing to over 1 0 for young primary impact craters these higher cpr values likely reflect surface roughness associated with these fresh features in contrast some craters in this region show elevated cpr in their interiors but not exterior to their rims almost all of these features are in permanent sun shadow and correlate with proposed locations of polar ice modeled on the basis of lunar prospector neutron data these relations are consistent with deposits of water ice in these craters

an olivine fabric database an overview of upper mantle fabrics and seismic anisotropy we present a unique database of 110 olivine petrofabrics and their calculated seismic properties the samples come from a variety of the upper mantle geodynamic environments ophiolites subduction zones and kimberlites with a wide range of micro structures a phenomenological relationship is established between p and s wave seismic anisotropy and the degree of crystal alignment fabric strength seismic anisotropy increases rapidly at low fabric strength before reaching a near saturation level of 15 to 20 for p waves and 10 to 15 for s waves despite a large variation in the symmetry of fabric patterns the average seismic properties of the different fabric micro structural and geodynamic settings have similar anisotropies in both magnitude and symmetry hence it would seem possible to determine some measure of fabric strength from seismic anisotropy if the dimensions of the anisotropic region are known but not geodynamic environment or details of the petrofabric pattern a simple pattern of seismic anisotropy characterises the average sample of the database which has the following features the polarisation plane of the fastest s wave is parallel or sub parallel to the foliation plane the maximum shear wave splitting is parallel to the y structural direction in foliation plane and normal to the lineation the maximum of the p wave velocity is parallel to the high concentration of 100 axes which is sub parallel to the lineation the 100 orientation distribution has the greatest influence on the p wave seismic anisotropy the 100 and 001 orientation distributions have the greatest influence on the symmetry of s wave anisotropy although the magnitude of anisotropy is influenced by the distribution of all three principal axes although the database only contains olivine petrofabrics this statistical study clearly shows that seismic anisotropy can be used to deduce the orientation of the structural frame in the upper mantle 1998 elsevier science b v all rights reserved

iron and titanium abundance and maturity degree distribution on the lunar nearside new digital images of the lunar nearside albedos at 0 42 0 65 0 75 and 0 95 m derived from telescopic data were used to map the abundance and distribution of iron titanium and maturity degree on the lunar nearside developing the approach by p luceyet al 1995 science268 1150 a method of separating contributions of the fe and ti abundance and maturity degree to spectral properties of the lunar surface is presented the main objective of the method is an analysis of the 3d correlation diagram of optical characteristics of regolith material with the aim of choosing a coordinate system providing the best correlations of these characteristics with fe and ti abundance data for the surveyor luna and apollo landing sites and with maturity degree laboratory measurements of lunar samples by e fischer and c pieters e g 1996 j geophys res 101 2225 to find the coordinates a geometrical optics model of light scattering in particulate media enabling to calculate the absorption coefficient from albedo measurements is used an analysis of the correlation diagram feo tio2provides two maps characterizing optical types of the lunar nearside in particular the maps show that the basalts of mare serenitatis and mare tranquillitatis are not widely extended on the lunar nearside the maturity degree parameteris feo was also mapped regions withis feo 50 are young craters surrounded by ray systems whereas the conditionis feo 70 corresponds to regions associated with copernicus ejecta western boundaries of mare tranquillitatis and mare serenitatis and a portion of the south highland the new map of feo distribution on the lunar nearside was used to study a correlation between iron content and distribution of remanent magnetism over the lunar surface the relationship obtained has a reverse behavior the lower the iron content the higher the magnetism

bayesian inversion of joint sh seismic and seismoelectric data to infer glacier system properties abstract in glacial studies properties such as glacier thickness and the basement permeability and porosity are key to understand the hydrological and mechanical behaviour of the system the seismoelectric method could potentially be used to determine key properties of glacial environments here we analytically model the generation of seismic and seismoelectric signals by means of a shear horizontal seismic wave source on top of a glacier overlying a porous basement considering a one dimensional setting we compute the seismic waves and the electrokinetically induced electric field we then analyse the sensitivity of the seismic and electromagnetic data to relevant model parameters namely depth of the glacier bottom porosity permeability shear modulus and saturating water salinity of the glacier basement moreover we study the possibility of inferring these key parameters from a set of very low noise synthetic data adopting a bayesian framework to pay particular attention to the uncertainty of the model parameters mentioned above we tackle the resolution of the probabilistic inverse problem with two strategies 1 we compute the marginal posterior distributions of each model parameter solving multidimensional integrals numerically and 2 we use a markov chain monte carlo algorithm to retrieve a collection of model parameters that follows the posterior probability density function of the model parameters given the synthetic data set both methodologies are able to obtain the marginal distributions of the parameters and estimate their mean and standard deviation the markov chain monte carlo algorithm performs better in terms of numerical stability and number of iterations needed to characterize the distributions the inversion of seismic data alone is not able to constrain the values of porosity and permeability further than the prior distribution in turn the inversion of the electric data alone and the joint inversion of seismic and electric data are useful to constrain these parameters as well as other glacial system properties furthermore the joint inversion reduces the uncertainty of the model parameters estimates and provides more accurate results

regolith composition and structure in the lunar maria results of long wavelength radar studies radar measurements at 70 cm and 7 5 m wavelengths provide insight into the structure and composition of the upper 5 100 m of the lunar regolith and crust we combine high resolution 3 5 km 70 cm radar data for the nearside with earlier calibrated full disk observations at the same wavelength to provide a reasonable estimate of the lunar backscatter coefficient these data are tested against models for echoes from a buried substrate and mie scattering from surface and buried rocks these mechanisms are expected to dominate the 70 cm radar echo with their relative importance determined by the rock population regolith depth substrate roughness and the loss tangent of the soil results indicate that the 70 cm radar echo for the maria comes largely from mie scattering by rocks buried within the fine soil radar scattering from a buried substrate is not likely to greatly affect the observed return we also compared the 70 cm and 7 5 m radar images to infrared eclipse temperature maps crater population age estimates for the maria and to tio2 and feo abundances inferred from earth based telescopic and clementine multispectral observations these data imply that 1 the tio2 ilmenite content of the regolith controls variations in 70 cm depolarized echo strength among mare units with higher titanium abundance leading to lower echoes 2 changes in the average 70 cm return for a given tio2 abundance between maria of different ages do occur but uncertainties in the current radar data do not allow us to uniquely distinguish between variations in rock population with age and calibration effects 3 the 7 5 m radar echoes are controlled by the age of the mare basalt flows with older deposits having a greater degree of fracturing and higher backscatter future mapping at 12 6 cm and 70 cm wavelengths will help to resolve some of the issues raised here

global regolith thermophysical properties of the moon from the diviner lunar radiometer experiment we used infrared data from the lunar reconnaissance orbiter lro diviner lunar radiometer experiment to globally map thermophysical properties of the moon s regolith fines layer thermal conductivity varies from 7 4 10 4 w m 1 k 1 at the surface to 3 4 10 3 w m 1 k 1 at depths of 1 m given density values of 1100 kg m 3 at the surface to 1800 kg m 3 at 1 m depth on average the scale height of these profiles is 7 cm corresponding to a thermal inertia of 55 2 j m 2 k 1 s 1 2 at 273 k relevant to the diurnally active near surface layer 4 7 cm the temperature dependence of thermal conductivity and heat capacity leads to a 2x diurnal variation in thermal inertia at the equator on global scales the regolith fines are remarkably uniform implying rapid homogenization by impact gardening of this layer on timescales 100 j m 2 k 1 s 1 2 in the interiors and ejecta of copernican aged impact craters and lower thermal inertia 50 j m 2 k 1 s 1 2 within the lunar cold spots identified by bandfield et al 2014 observed trends in ejecta thermal inertia provide a potential tool for age dating craters of previously unknown age complementary to the approach suggested by ghent et al 2014 several anomalous regions are identified in the global 128 pixels per degree maps presented here including a high thermal inertia deposit near the antipode of tycho crater

an analytical solution to assess the sh seismoelectric response of the vadose zone fil monachesi leonardo bruno universidad nacional de rio negro sede alto valle instituto de investigaciones en paleobiologia y geologia argentina consejo nacional de investigaciones cientificas y tecnicas argentina

near surface mapping using sh wave and p wave seismic land streamer data acquisition in illinois u s human activities have considerable impact on the upper 300 m of sediments of the earth conflicting activities in highly populated areas involving groundwater exploitation aggregate extraction and hazardous chemical related production and storage induce stress on the environment nearly half the population living around the great lakes depends on shallow groundwater aquifers a coalition of four great lakes states illinois indiana michigan and ohio in conjunction with the u s geological survey has initiated a program to map this sensitive upper 300 m layer as part of this effort the illinois state geological survey isgs has undertaken the task of preparing 3d quadrangle maps of the upper 100 m of the entire state at a scale of 1 24 000 although large scale maps indicating potential aquifer contamination already exist figure 1 very little is known about the groundwater pathways through the upper sedimentary column which mainly consists of deposits from the quaternary continental glacier

lithosphere and asthenosphere of the tien shan imaged by s receiver functions 1 the s receiver function technique was applied to the recordings from 36 broad band stations in the tien shan the results reveal a pronounced difference in the properties of the lithosphere asthenosphere of the tien shan and those of the neighboring platforms beneath the tien shan an upper mantle lid with an s velocity of about 4 5 km s is underlain at a depth of about 90 km by a low velocity zone where the s velocity drops to 4 1 4 2 km s trends of p and s travel time residuals are consistent with the presence of melt or other liquids in this zone there is no evidence of any similar layer beneath the platforms the crust is 55 65 km thick beneath most of the tien shan and 45 km below the platforms although it thins to about 45 km near the naryn basin in the central tien shan

shear wave splitting at central tien shan evidence for rapid variation of anisotropic patterns at active collisional belts the fast polarization axis of shear wave splitting is generally aligned parallel to the strike of the belt which has been proposed to indicate mantle strain that is coherent with crustal deformation a notable exception is central tien shan where anomalous patterns of splitting have previously been observed we here analyze shear wave splitting of sks phases across north central tien shan using digital data from the kyrgyzstan broadband seismic network knet we find a pattern of short wavelength anisotropic heterogeneity that supports complex mantle flow due to small scale convection the along strike variations in mantle structure contrast with the coherent pattern of crustal shortening and indicate that mantle flow is not directly coupled to crustal deformation in this region

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

surface morphology of domes in the marius hills and mons rumker regions of the moon from earth based radar data 1 clusters and coalesced complexes of domes represent a relatively rare landform within the extensive low relief lunar maria while they are typically spectroscopically similar to mare basalts emplaced by high volume low viscosity eruptions the large scale morphology of the domes is more consistent with slower emplacement and or more viscous magma we use new earth based radar data to study the decimeter to meter scale rock abundance at the surface and buried within the probing range of the radar signal of domes in the marius hills and mons rumker regions domes of the marius hills are characterized by high circular polarization ratio cpr values at 12 6 cm and 70 cm wavelength similar to the near rim ejecta deposits of young lunar craters like tycho areas of large ejecta fragments near the rim of meteor crater and blocky lavas such as sp flow in arizona we infer that a very rugged flow surface morphology associated with the original dome forming eruption rather than postemplacement modification exists beneath at most a few meters of regolith magmas with greater silica content than sampled lunar basalts are unlikely so the blocky structure of the dome forming lava must arise from some combination of compositional change effusion rate and or cooling effects not typically observed in basaltic landforms on the earth much of the 80 km diameter mons rumker has low backscatter and cpr at 12 6 cm wavelength relative to nearby mare terrain at 70 cm wavelength the northern and most of the southern parts of the complex are radar dark but there is a radar bright feature that extends from the central region eastward into oceanus procellarum we conclude that much of mons rumker is mantled by rock poor fine grained pyroclastic material the radar bright feature in the 70 cm map is detectable owing to some combination of greater roughness like the marius domes and thinner mantling cover

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

global elemental maps of the moon the lunar prospector gamma ray spectrometer lunar prospector gamma ray spectrometer spectra along with counting rate maps of thorium potassium and iron delineate large compositional variations over the lunar surface thorium and potassium are highly concentrated in and around the nearside western maria and less so in the south pole aitken basin counting rate maps of iron gamma rays show a surface iron distribution that is in general agreement with other measurements from clementine and the lunar prospector neutron detectors

shear wave reflection seismics as a valuable tool for near surface urban applications subsurface investigations in urban areas have to take sealed surfaces and densely built and populated areas into account the shear wave reflection seismic system developed at the leibniz institute for applied geophysics liag provides a solution for this acquisition technology problem using horizontally polarized shear waves sh waves and noninvasive source and receiver designs

anisotropy of the mantle inferred from observations of p to s converted waves summary seismic anisotropy has been previously studied at depths usually not exceeding 100 or 150 km in this paper we present a method of analysis of seismic records which is very sensitive to azimuthal anisotropy and is applicable at almost any depth range the idea of the method is to detect and analyse the sh component of the waves converted from p to s in the mantle the procedure of record processing includes frequency filtering axis rotation transformation of the record to a standard form stacking the standardized sh component records of many seismic events and the harmonic analysis of amplitude as a function of the direction of wave propagation when applied to the long period records of norsar the procedure detected a converted wave with the properties implying the possibility of its propagation in a transversely isotropic medium with a horizontal axis of symmetry our preferred model postulates anisotropy of 1 per cent in a layer 50 km thick at the base of the upper mantle

towards 3 d fabric in the continental lithosphere and asthenosphere the tien shan 1 as shown by previous observations of shear wave splitting of the sks phase the fast direction of azimuthal anisotropy beneath the tien shan tends to be aligned with the strike of the belt this direction implies that the anisotropy is related to the current orogenesis now we describe an attempt to constrain the distribution of the anisotropy with depth by combining observations of sks and p receiver functions the data are inverted for the parameters of anisotropy with the aid of a genetic algorithm the results of the joint inversion suggest that the actual distribution of anisotropy with depth can be more complicated than usually thought the deformed mantle layer can be a few hundred kilometres thick in the most reliable models fast direction of anisotropy in the shallow mantle is significantly different from that inferred from the observations of sks at some stations the data require anisotropy in the crust

a multispectral geological study of the schrodinger impact basin1 schrodinger basin is a well preserved peak ring basin located on the lunar farside along the rim of the much larger south pole aitken spa basin the relatively young age lower imbrian series

velocity shift in heterogeneous media with anisotropic spatial correlation summary converted waves analysis is used to map the anisotropy as a function of depth in the upper mantle stacking of sv a ndt component records of several seismic events well distributed in azimuth helps to detect these converted waves weighting coe cients are used to extract the anisotropic signal in the records synthetic examples show that a harmonic analysis helps to separate azimuthal anisotropy eiects from the eiects of lateral heterogeneity such as those resultingfrom dipping structures a good azimuthal coverage of the data set is important in order to separate the diierent eiects in the stack sections obtained for diierent azimuthal orders the procedure is applied to data observed at geoscope station can and gives a model with two anisotropic layers in the upper mantle the upper layer located between the crust and a depth of140 km has its fast axis in an east west direction the lower layer 40 km thick has its fast axis in a north south direction the fast axis directions are in agreement with results obtained from surface wave analysis and tectonic information

lunar fe and ti abundances comparison of lunar prospector and clementine data the lunar prospector neutron spectrometer data correlate well with iron and titanium abundances obtained through analysis of clementine spectral reflectance data with the iron and titanium dependence removed the neutron spectrometer data also reveal regions with enhanced amounts of gadolinium and samarium incompatible rare earth elements that are enriched in the final phases of magma crystallization these regions are found mainly around the ramparts of the imbrium impact basin but not around the other basins including the much larger and deeper south pole aitken basin this result confirms the compositional uniqueness of the surface and interior of the imbrium region

mountain building strike parallel motion and mantle anisotropy abstract geophysical and geological evidence indicates that tectonic movements parallel to the strike of orogenic belts and suture zones are the most important mode of displacement during continental collision and oblique subduction several hundred to a few thousand kilometers of displacement may have occurred this way resulting in a pervasive ductile deformation of the lithosphere consequently both crustal and mantle fabrics may reflect these movements and their study using both geological and geophysical methods could supply important clues to lithosphere behavior during mountain building on the basis of kinematic analysis of ductilely deformed crustal rocks in zones of movement a variety of tectonic models have been proposed which differ in 1 1 the timing of strike parallel motions early before or during continental accretion or late after accretion was completed 2 2 the geometric pattern of strike parallel displacement zones low angle or high angle and 3 3 the location of orogen parallel movement zones in outboard terranes on the subducting plate along the suture zone or within the continental hangingwall large scale displacements parallel to mountain belts also suggest that they occurred along lithospheric faults rooted in the upper mantle although few studies have been carried out from this view point thermal structural and petrological data support the conclusion that lithospheric faults involving the upper mantle may be discriminated from crustal faults rooted in some crustal decoupling zone where available data on mantle flow beneath orogenic belts are in agreement with mountain parallel displacements inferred from crustal studies this has an important bearing on the seismic anisotropy pattern which can be predicted in the lithospheric mantle below mountain belts the fast velocity direction which is parallel to the flow direction should therefore be recorded parallel to the strike of the belt

receiver function tomography of the central tien shan abstract to obtain an image of the deep structure of the tien shan in central asia we invert p and s receiver functions jointly for almost 40 local broad band seismograph stations the inversion is performed using a simulated annealing technique the combined inversion is an improvement on earlier studies where p and s receiver functions were inverted separately using this approach we deal with structural imaging problems that are usually investigated with teleseismic body wave and surface wave tomography techniques we demonstrate that the uppermost mantle in the north of the central tien shan is composed of a high velocity lid a few tens of kilometers thick above a pronounced low velocity zone the crustal structure in this region provides evidence of magmatic underplating these features are likely related to a small plume that is manifested by basaltic eruptions of cretaceous paleogene age the low velocity layer is also found in a southeast trending corridor which may correspond to the bachu uplift in the tarim basin crustal thickness beneath the orogen varies from about 45 to about 70 km the smallest values most likely inherited from the pre orogenic era are found in a neighborhood of the talas fergana fault similar values are characteristic of the kazakh shield in the north and the tarim basin in the south the largest values are found beneath the bounding ranges we infer that uplift of the central tien shan is unlikely to be caused by crustal shortening alone

compositional analyses of lunar pyroclastic deposits abstract the 5 band clementine uvvis data at 100 m pixel were used to examine the compositions of 75 large and small lunar pyroclastic deposits lpds and these were compared to representative lunar maria and highlands deposits results show that the albedo spectral color and inferred composition of most lpds are similar to those of low titanium mature lunar maria these lpds may have consisted largely of fragmented basalt with substantial components of iron bearing mafic minerals pyroxenes olivine and smaller amounts if any of volcanic glass several smaller lpds also show substantial highland components three classes of very large deposits can be distinguished from most lpds and from each other on the basis of crystallinity and possible titanium content of their pyroclastic components one class has spectral properties that are dominated by high titanium crystallized black beads e g taurus littrow a second consists of a mixture of high titanium glasses and beads with a higher glass bead ratio sulpicius gallus than that of taurus littrow and a third has a significant component of quenched iron bearing volcanic glasses aristarchus with possible moderate titanium contents although areally extensive these three classes of very large pyroclastic deposits compose only 20 of the 75 deposits studied 27 and eruption of such materials was thus likely to have been less frequent on the moon

complex seismic anisotropic structure beneath the central tien shan revealed by shear wave splitting analyses summary shear wave splitting parameters fast polarization directions and splitting times obtained at the permanent broad band station wushi wus which is situated in central tien shan china demonstrate systematic azimuthal variations the fast polarization directions range from 26 to 85 and the delay times range from 0 4 to 1 6 s suggesting a complex anisotropic structure that cannot be adequately explained by a single anisotropic layer with horizontal axis of symmetry the azimuthal variations have an apparent 90 periodicity and thus can be best explained by a two layer anisotropic model with horizontal symmetry axes the optimal fast direction for the upper layer is in the 60 80 range that is subparallel to the strike of the tien shan orogenic belt and can consequently be attributed to the ongoing n s directed shortening the fast direction for the lower layer ranges from 85 to 105 and can be explained by lattice preferred orientation of olivine crystals in the asthenosphere associated with present day absolute plate motion of the eurasian plate

s waves and the near surface a time lapse study of s wave velocity and attenuation in the weathering layer of an alberta heavy oil field this study used data from a three month continuous reservoir monitoring experiment in peace river alberta canada to measure spatial and temporal variations in near surface s wave velocity vs and attenuation qs in the weathering layer the permanently buried sources generate a strong refracted s wave that was recorded on buried 3c receivers a method to perform receiver side up down separation and extract primary and ghost s wavefields is presented these wavefields are then used to measure near surface vs and qs for the near surface layer above the buried receivers which is the top 12 m in this case the measured vs values range between 180 and 220 m s and qs values between 8 and 22 maps of vs and qs show a robust correlation low vs with low qs and a clear spatial variation that can be associated with soil type both properties increase slowly over a three month period in one section of the survey area while remaining constant in another the cumulative increase in vs and qs is 10

near surface fault detection using high resolution shear wave reflection seismics at the co2crc otway project site australia high resolution near surface shear wave reflection seismic measurements were carried out in november 2013 at the co2crc otway project site victoria australia with the aim to determine and if so where deeper faults reach the near subsurface from a previous p wave 3 d reflection seismic data set that was concentrated on a reservoir at 2 km depth we can only interpret faults up to 400 m below sea level for the future monitoring in the overburden of the co2 reservoir it is important to know whether and how the faults continue in the subsurface we prove that two regional fault zones do in fact reach the surface instead of dying out at depth individual first break signatures in the shot gathers along the profiles support this interpretation however this finding does not imply perforce communication between the reservoir and the surface in the framework of co2 injection the shear wave seismic sections image with high resolution better than 3 m vertically and complementary to existing p wave volumes different tectonic structures similar structures also outcrop on the southern coast of the otway basin both the seismic and the outcrops evidence the complex youngest structural history of the area

lithospheric structure of the central himalaya from 3 d tomographic imaging abstract the high himalaya are one of the most spectacular consequences of the ongoing collision between india and eurasia yet the role that the lithosphere beneath them play in this collision is not well understood to illuminate the influence of the himalaya on collisional processes we produced tomographic images of the subsurface beneath them from arrival times of p and s waves generated by 551 teleseisms and 1051 local regional events and recorded by the himalayan nepal tibet broadband seismic experiment himnt from 2001 to 2002 compared to those in initial 1d models the rms p and s arrival time misfits in our final 3d model were reduced by as much as 46 from 0 45 s to 0 24 s and 38 from 0 97 s to 0 6 s respectively our results show strong crustal variations perpendicular to but no significant lateral variation along the trend of the high himalaya within our study area in the ns direction the crust thickens from about 60 km under the lesser himalaya to 70 80 km under the tethys himalaya there is no localized crustal thickening beneath the high himalaya wavespeeds and seismicity patterns beneath the tethys himalaya suggest that the middle crust at 30 50 km depth is ductile and are consistent with the presence of a mid crustal reflector associated with the stronger gradients in the lower crust correlation between relocated earthquakes and the xainza dinggye rift indicates that the rift is not cutting through the crust at the present time shear wave splitting from core phases indicates that the upper mantle beneath the tethys himalaya is nearly isotropic the combination of isotropy and higher seismic wavespeed leads us to suggest that eclogites included in the lowermost crust and the uppermost mantle are responsible for the mid crustal reflector under the tethys himalaya as well as for a slightly high wavespeed anomaly just beneath the moho this interpretation is supported by the existence of granulitic eclogite in the ama drime massif 50 km northeast of mt everest

rugged lava flows on the moon revealed by earth based radar 1 basaltic volcanism is widespread on the lunar nearside and returned samples suggest that the mare forming magmas had low viscosity that led to primarily sheet like deposits new 70 cm wavelength radar observations that probe several meters beneath the lunar surface reveal differences in mare backscatter properties not explained by age or compositional variations we interpret areas of high backscatter and high circular polarization ratio in maria serenitatis imbrium and crisium as having an enhanced abundance of decimeter scale subsurface rocks relative to typical mare forming flows the 3 5 b y survival of these differences implies an initial platy blocky or ridged lava flow surface layer with thickness of at least 3 5 m such rugged morphology might arise from episodic changes in magma effusion rate as observed for disrupted flood basalt surfaces on the earth and mars very high flow velocities or increased viscosity due to a number of factors significant information on lunar mare eruption conditions may thus be obtained from long wavelength radar probing of the shallow subsurface

lunar rare earth element distribution and ramifications for feo and tio2 lunar prospector neutron spectrometer observations lunar prospector neutron spectrometer data have been used to map the global surface distribution of the incompatible rare earth elements gadolinium and samarium from the low altitude 30 15 km mapping orbit these results afford improved surface resolution and detailed views of the potassium rare earth elements and phosphorus kreep distribution within and around mare imbrium and elsewhere the gd and sm results serve as a complementary and independent check of the distribution of kreep on the moon in contrast with the lunar prospector gamma ray spectrometer results for thorium the neutron spectrometer observations reflect the presence of fe and ti as well as gd and sm the contributions of fe and ti are removed using high spatial resolution clementine spectral reflectance determinations of feo and tio2 abundances overall the resulting gd and sm abundance map agrees with the th abundance map determined using the lunar prospector gamma ray spectrometer in general the detailed features of the procellarum imbrium kreep terrane are found in both for example distinct highs in gd sm and th abundances are resolved over the craters mairan aristarchus kepler reinhold lalande and aristillus over the apennine bench and fra mauro regions and over the montes jura and montes carpatus indicating an enhanced abundance of kreep in these locations the neutron observations also provide constraints on feo and tio2 abundances for some high ti locales there is a significant disagreement with tio2 abundances inferred from clementine spectral reflectance

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 compositional and physical properties of localized lunar pyroclastic deposits abstract lunar localized pyroclastic deposits are low albedo deposits with areas 2 these deposits were difficult to study before the turn of the millennium because of the lack of available high spatial resolution data with the launch of the lunar reconnaissance orbiter kaguya and chaandrayan 1 new sets of diverse high spatial resolution data are now available using several of these data sets we conducted a study of 34 localized pyroclastic deposits globally for each localized pyroclastic deposit we examined topography to estimate pyroclastic volume and juvenile proportions s band radar backscatter thermal infrared derived measures of surficial rock abundance and regolith density and mineral abundances our goals are to 1 quantitatively characterize the physical and mineralogical properties of each localized pyroclastic deposit 2 investigate the physical and mineralogical variations among localized pyroclastic deposits 3 compare these properties of localized 2 to regional pyroclastic deposits 2500 km 2 and 4 provide useful parameters for future volcanological modeling from this study we find that 1 localized pyroclastic deposits exhibit low relief structures 2 the surface rock abundance and circular polarization ratio of localized pyroclastic deposits display a wide range of values 0 2 0 5 and 0 3 0 6 respectively 3 the glass abundance of localized pyroclastic deposits vary between 0 and 80 wt 4 there are four types of localized pyroclastic deposits based upon the surface rock abundance and glass abundance parameters 5 pyroclastic deposits within the same floor fractured crater tend to have similar properties and 6 localized pyroclastic deposits are diverse with respect to regional pyroclastic deposits but a subset of localized pyroclastic deposits have similar physical and mineralogical properties to regional pyroclastic deposits

clementine uvvis multispectral data and the apollo 17 landing site what can we tell and how well multispectral data obtained by the clementine mission are correlated to compositional and petrographic information for individual sample stations at the apollo 17 landing site the soils contain a variety of fe2 bearing phases in different proportions including low and high ca pyroxene olivine ilmenite and glass in the mare soils ilmenite carries a substantial proportion of the fe2 and in all soils glasses particularly agglutinates carry nearly as much or more fe2 as the silicates using an empirical calibration concentrations of feo and tio2 estimated from the ultraviolet visible uvvis data correlate well with measured compositions of surface soils yielding correlation coefficients of 0 94 and 0 95 respectively the ferrous absorption however is weak in the mostly submature to mature apollo 17 soils thus spectral curvature is useful only for investigating the mafic silicate mineralogy around fresh craters and deposits the effects of local topography cause significant variations in feo and tio2 derived from clementine uvvis data but do not impair first order geologic interpretations parameters derived from the uvvis data allow quantification of the composition and nature of the soils and by inference underlying rock formations and are consistent with the known geologic character of the landing site the highland regions along this part of the serenitatis rim are relatively feo rich partly as a result of abundant mafic impact melt breccia and partly from the addition of basaltic material in the form of impact debris and pyroclastic deposits at high elevations massif soils are rich in a mafic melt breccia component although slopes and areas mixed by small craters reveal a mixture of melt breccia and older highland material of anorthositic norite composition soils developed on hummocky deposits that postdate the massifs such as the sculptured hills have a similar range of compositions as the massifs elevated plains northeast of the sculptured hills are more mafic than the known impact melt breccias suggesting that they may also contain an older volcanic component sources of low ti basalt or very low ti basalt though not present in the immediate vicinity of the landing site occur east and northeast of taurus littrow valley and are readily identified using the uvvis data

abundance and distribution of iron on the moon the abundance and distribution of iron on the moon is derived from a near global data set from clementine the determined iron content of the lunar highlands crust 3 percent iron by weight supports the hypothesis that much of the lunar crust was derived from a magma ocean the iron content of lower crustal material exposed by the south pole aitken impact basin on the lunar farside is higher 7 to 8 percent by weight and consistent with a basaltic composition this composition supports earlier evidence that the lunar crust becomes more mafic with depth the data also suggest that the bulk composition of the moon differs from that of the earth9s mantle this difference excludes models for lunar origin that require the earth and moon to have the same compositions such as fission and coaccretion and favors giant impact and capture

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

depth localized azimuthal anisotropy from sks and p receiver functions the tien shan summary shear wave splitting in the seismic sks phase provides a unique possibility to judge on deformations at depths inaccessible for direct observations fast s wave polarization direction in collisional belts is often parallel to the trend of the belt although deformations of the mantle lithosphere in low angle thrusts would lead to the fast polarization direction normal to the trend of the belt these considerations suggested that the upper mantle in collisional belts is decoupled from the crust however sks technique is notable by a poor depth resolution and usually it assumes that the fast polarization direction is the same at any depth which is hard to justify here to investigate depth dependent azimuthal anisotropy in the mantle we invert jointly p receiver functions and sks particle motions at a number of seismograph stations the technique involves azimuthal filtering of the receiver functions and provides a criterion to discriminate between the effects of azimuthal anisotropy and lateral heterogeneity of isotropic medium a search for the optimum models is conducted with a technique similar to simulated annealing testing with synthetics demonstrates that this approach is robust the results for 10 seismograph stations in the tien shan the world s most active intracontinental collisional belt in central asia reveal a pronounced change in the patterns of azimuthal anisotropy at a depth around 100 km in the mantle lithosphere at depths less than 100 km anisotropy is relatively weak and fast wave polarization direction varies laterally in a broad range this layer is not necessarily decoupled from the crust its anisotropy can be a combined effect of present day thrusting and of deformations of the geologic past in the lower layer asthenosphere the average azimuth of fast wave polarization is close to the trend of the belt whereas magnitude of s wave anisotropy is stable and large between 5 and 6 per cent this anisotropy is a likely result of recent uniaxial shortening at right angle to the trend of the belt at some stations the data require anisotropy in the crust there is no evidence for anisotropy at depths exceeding 150 250 km

directional variations in travel time residuals of teleseismic p waves in the crust and mantle beneath northern tien shan we study the directional variation in travel time residuals using 13 820 p wave arrivals from 1 998 teleseismic events 15 d 98 4 1 mb 7 3 recorded in 1991 1997 by the kyrgyz digital seismic network knet based on a modified version of the iasp91 model that accounts for the kyrgyz crustal thickness beneath knet we convert p wave travel times to travel time residuals dt the de pendence of dt on backazimuth is modeled as one two and four lobed variations in a horizontal plane backus 1965 a least squares fit of the azimuthal variation of dt indicates that the crust in the northern tien shan is about 11 15 km thicker than it is in the kazakh shield and the chu depression from nine knet stations the one lobe model estimates that the slowest p wave travel time direction is 5 0 4 8 almost directly north and the magnitude of variation is 1 71 0 13 sec this result is consistent with an upwelling lower mantle plume for the two lobe model the slowest p wave travel time directions anisotropy term are 89 7 and 269 7 4 7 i e trending east west we find p wave velocity anisotropy of 2 0 2 9 associated with a layer with a thickness of 440 km at the top of the lower mantle the fast direction of the p wave travel time north south azimuthal anisotropy at the top of the lower mantle is 1 parallel to the absolute motion of the india plate and 2 close to the direction of the upwelling hot mantle flow the last result suggests that the azimuthal aniso tropy of the travel time residuals is due to the shape preferred orientation of middle mantle material that results from plume intrusion shear wave splitting studies mak eyeva et al 1992 wolfe and vernon 1998 estimated the fast polarization direction to be parallel to the strike of the geological structures of the northern tien shan 71 29 thus the fast polarization direction determined from these shear wave splitting studies using knet data contradicts differs by 90 the fast travel time direction 0 3 and 179 7 4 7 we determine here using p wave travel time residuals using knet data this suggests that the azimuthal anisotropy determined from p wave travel time variations and from shear wave splitting in sks and skks have different sources

shear wave splitting beneath the central tien shan and tectonic implications 1 shear wave splitting analyses were performed at 30 seismic stations in the central tien shan and its vicinity fast orientation at most of the stations on the tien shan range is ene wsw parallel to the strike of the tien shan it largely reflects a coherent deformation of the lithosphere in response to the ns shortening anisotropy with nne ssw fast axes is observed within adjacent basins around the issyk kul and near the northwestern tarim where the lithosphere is presumably strong less deformed the nne ssw orientation which coincides with the surface velocity of the central tien shan can be best explained by shear between the lithosphere and asthenosphere on a regional scale rather than small scale convection as proposed in previous studies the dextral talasso fergana fault seems to have little effect on anisotropy at its nearby stations suggesting this fault is probably confined to the shallow part of the lithosphere

no evidence for thick deposits of ice at the lunar south pole the rim of the shackleton crater at the lunar south pole is a candidate crash site for nasa s lcross probe lunar crater observation and sensing satellite due to launch in 2008 the plume of debris kicked up by the crash is to be analysed in the hope that it will reveal the water thought to be there suggestions of lunar ice date from 1996 when data from the clementine spacecraft gave some indications of the presence of ice on crater walls at the south pole now using high resolution radar imagery the radar scattering parameter thought indicative of thick ice deposits has been found also to match radar echoes from the rock strewn walls and ejecta of young impact craters at all lunar latitudes there is no evidence for thick ice though there could be grains of water ice spread more thinly through the lunar soil shackleton crater at the moon s south pole has been suggested as a possible site of concentrated deposits of water ice on the basis of modelling of bi static radar polarization properties and interpretations of earlier earth based radar images1 2 this suggestion and parallel assumptions about other topographic cold traps is a significant element in planning for future lunar landings hydrogen enhancements have been identified in the polar regions3 but these data do not identify the host species or its local distribution the earlier earth based radar data lack the resolution and coverage for detailed studies of the relationship between radar scattering properties cold traps in permanently shadowed areas and local terrain features such as the walls and ejecta of small craters here we present new 20 m resolution 13 cm wavelength radar images that show no evidence for concentrated deposits of water ice in shackleton crater or elsewhere at the south pole the polarization properties normally associated with reflections from icy surfaces in the solar system4 5 6 were found at all the observed latitudes and are strongly correlated with the rock strewn walls and ejecta of young craters including the inner wall of shackleton there is no correlation between the polarization properties and the degree of solar illumination if the hydrogen enhancement observed by the lunar prospector orbiter3 indicates the presence of water ice then our data are consistent with the ice being present only as disseminated grains in the lunar regolith

bistatic radar observations of the moon using mini rf on lro and the arecibo observatory the miniature radio frequency mini rf instrument aboard nasa s lunar reconnaissance orbiter lro is a hybrid dual polarized synthetic aperture radar sar that operated in concert with the arecibo observatory to collect bistatic radar data of the lunar nearside from 2012 to 2015 the purpose of this bistatic campaign was to characterize the radar scattering properties of the surface and near surface as a function of bistatic angle for a variety of lunar terrains and search for a coherent backscatter opposition effect indicative of the presence of water ice a variety of lunar terrain types were sampled over a range of incidence and bistatic angles including mare highland pyroclastic crater ejecta and crater floor materials responses consistent with an opposition effect were observed for the ejecta of several copernican aged craters and the floor of the south polar crater cabeus the responses of ejecta material varied by crater in a manner that suggests a relationship with crater age the response for cabeus was observed within the portion of its floor that is not in permanent shadow the character of the response differs from that of crater ejecta and appears unique with respect to all other lunar terrains observed analysis of data for this region suggests that the unique nature of the response may indicate the presence of near surface deposits of water ice

an analysis of the mariner 10 color ratio map of mercury abstract the results of a geological analysis of the mariner 10 orange uv color ratio man of mercury b hapke c christman b rava and j mosher proc lunar planet sci conf 11th 1980 pp 817 822 are given certain errors that occured in reproducing the published version of the 1980 map are pointed out the relationships between color and terrain are distinctly nonlunar there is no correlation between color boundaries and the smooth plains on mercury in contrast to the strong correlation between color and maria highlands contacts on the moon there are no large exposures of low albedo blue material that could be considered to be mercurian analogs of high fe ti lunar maria basalts on any part of mercury imaged by mariner 10 three lines of evidence imply that the crust is low in fe2 and ti4 rays and ejecta blankets are bluer than most areas on mercury the fe2 band in mercury s reflectance spectrum is very weak or nonexistent and the albedo contrasts are smaller than those on the moon there is no evidence in the spectral or albedo data that a lunar type of second wave of melting ever occured on mercury rather the observations are most consistent with the hypothesis that the smooth plains are extrusive landforms derived from local material possibly mobilized by the caloris event in several places correlations between color and topography can be explained if older redder higher fe materials underlie younger bluer lower fe surfaces there is some evidence of late fe rich pyroclastic like activity

the relationship between radar scattering and surface roughness of lunar volcanic features lunar roughness measurements derived from the lunar orbiter laser altimeter are compared to 12 6 cm wavelength radar data collected by the miniature radio frequency instrument and 70 cm wavelength radar data collected by the arecibo observatory these data are compared to assess how surface and subsurface roughness are correlated and affected by parameters including age and composition at length scales between 0 1 and 100 m a range of features are analyzed including volcanic domes marius hills rumker hills gruithuisen and mairan domes mare imbrium serenitatis and oceanus procellarum pyroclastic dark mantle deposits sinus aestuum sulpicius gallus and mare vaporum and two young craters copernicus and tycho statistically significant positive correlations exist between topographic roughness and both p and s band circular polarization ratios the strongest correlation is observed at the longest length scales correlations weaken as length scales become less similar potentially due to distinct processes controlling surface modification roughness is not significantly correlated with local slope although the marius hills are compositionally distinct from the gruithuisen and mairan domes they are indistinguishable in roughness characteristics conversely the rumker hills mare and dark mantle deposits are smoother at the length scales examined possibly due to fine grained mantling of regolith or pyroclastic deposits the floor and ejecta of tycho are the roughest surfaces measured in this study while the floor and ejecta of copernicus overlap the roughness distribution of the volcanic features this study shows that many factors control the evolution of roughness over time on various length scales

radar remote sensing of pyroclastic deposits in the southern mare serenitatis and mare vaporum regions of the moon 1 we use polarimetric radar observations to study the distribution depth and embedded rock abundance of nearside lunar pyroclastic deposits radar images were obtained for mare vaporum and the southern half of mare serenitatis the imaged areas contain the large rima bode mare vaporum sulpicius gallus and taurus littrow pyroclastic deposits potential pyroclastic deposits at rima hyginus crater the tacquet formation and a dome in mare vaporum are also included data were acquired at s band 12 6 cm wavelength using arecibo observatory and the green bank telescope in a bistatic configuration the s band images have resolutions between 20 and 100 m pixel the pyroclastic deposits appear dark to the radar and have low circular polarization ratios at s band wavelengths because they are smooth easily penetrable by radar waves and generally contain few embedded blocks changes in circular polarization ratio cpr across some of the pyroclastic deposits show areas with increased rock abundance as well as deposits that are shallower radar backscatter and cpr maps are used to identify fine grained mantling deposits in cases where optical and near infrared data are ambiguous about the presence of pyroclastics the tacquet formation in southern serenitatis areas near hyginus crater and a dome in mare vaporum have lower backscatter cross sections than would be expected for mare basalts of similar estimated titanium content combined with very low cpr values this is strong evidence that these areas are covered in fine grained pyroclastic mantling material

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

complex explosive volcanic activity on the moon within oppenheimer crater abstract oppenheimer crater is a floor fractured crater located within the south pole aitken basin on the moon and exhibits more than a dozen localized pyroclastic deposits associated with the fractures localized pyroclastic volcanism on the moon is thought to form as a result of intermittently explosive vulcanian eruptions under low effusion rates in contrast to the higher effusion rate hawaiian style fire fountaining inferred to form larger regional deposits we use lunar reconnaissance orbiter camera images and diviner radiometer mid infrared data chandrayaan 1 orbiter moon mineralogy mapper near infrared spectra and clementine orbiter ultraviolet visible camera images to test the hypothesis that the pyroclastic deposits in oppenheimer crater were emplaced via vulcanian activity by constraining their composition and mineralogy mineralogically we find that the deposits are variable mixtures of orthopyroxene and minor clinopyroxene sourced from the crater floor juvenile clinopyroxene and juvenile iron rich glass and that the mineralogy of the pyroclastics varies both across the oppenheimer deposits as a whole and within individual deposits we observe similar variability in the inferred iron content of pyroclastic glasses and note in particular that the northwest deposit associated with oppenheimer u crater contains the most iron rich volcanic glass thus far identified on the moon which could be a useful future resource we propose that this variability in mineralogy indicates variability in eruption style and that it cannot be explained by a simple vulcanian eruption a vulcanian eruption should cause significant country rock to be incorporated into the pyroclastic deposit however large areas within many of the deposits exhibit spectra consistent with high abundances of juvenile phases and very little floor material thus we propose that at least the most recent portion of these deposits must have erupted via a strombolian or more continuous fire fountaining eruption and in some cases may have included an effusive component these results suggest that localized lunar pyroclastic deposits may have a more complex origin and mode of emplacement than previously thought

a comparison of rayed craters on the moon and mercury 1 observations of rayed craters at optical and radar wavelengths provide insight into the processes that lead to ray formation and degradation on terrestrial planets we have compared optical and s band radar data for several large 20 km diameter young craters on the moon and mercury and find evidence that secondary cratering plays a significant role in the formation of crater rays regions where rays appear bright to optical and radar sensors correspond to dense concentrations of secondary craters and the observed radar enhancement appears to be a result of the deposition of blocky immature ejecta from the secondary craters and or the rocky immature interior walls of the secondary craters we define a new optical maturity index for mercury and find that rays in radar and optical images correspond closely indicating that the rays are rich in centimeter to decimeter sized clasts rays on the moon are less prominent at radar wavelengths suggesting that they are currently composed of smaller clasts centimeter sized or less this difference suggests that secondary craters are larger on mercury and capable of excavating more decimeter sized clasts furthermore observations of rayed craters provide an opportunity to assign relative ages to the youngest craters on the moon and mercury although rayed craters on mercury appear most similar to the youngest craters on the moon the apparent ages are more likely influenced by inherent differences in impact velocity surface gravitational acceleration and target properties that result in the formation of larger secondary craters on mercury

tomographic image of the crust and upper mantle beneath the western tien shan from the manas broadband deployment possible evidence for lithospheric delamination abstract we combine teleseismic p arrival times from the recent manas deployment of broadband sensors with p and s arrival times from local events recorded by the genghis deployment and analog observations from the kyrgyz institute of seismology to generate a high resolution 20 km image of elastic wavespeeds in the crust and upper mantle beneath the western tien shan the total data set consists of 29 006 p and 21 491 s arrivals from 2176 local events recorded at 144 stations along with 5202 p arrivals from 263 teleseismic events recorded at 40 stations the most significant feature in our image of the mantle beneath the tien shan is a pair of large elongated high wavespeed regions dipping in opposite directions from the near surface to depths of at least 400 km these regions appear to be continuous and extend upwards to bounding range fronts where the tarim basin is being overthrust by the kokshal range on the south side and the kazach shield underthrusts the kyrgyz range on the north side while it is tempting to interpret these high wavespeed anomalies as evidence for contemporary subduction of continental lithosphere such a scenario is difficult to reconcile with both the timing of the orogen and the size of the wavespeed anomaly we suggest instead that they represent downwelling side limbs of a lithospheric delamination beneath the central part of the tien shan possibly by siphoning of the bordering continental lithosphere as the central part descends

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

the surficial nature of lunar swirls as revealed by the mini rf instrument abstract lunar swirls are optically bright sinuous albedo features found on the moon the mini rf synthetic aperture radar on the lunar reconnaissance orbiter has provided a comprehensive set of x and s band radar images of these enigmatic features including the first radar observations of swirls on the farside of the moon a few general remarks can be made about the nature of the lunar swirls from this data set first the average radar properties of lunar swirls are identical to nearby non swirl regions in both total radar backscatter and circular polarization ratio cpr this implies that average centimeter scale roughness and composition within the high albedo portions of the swirls do not differ appreciably from the surroundings and that the high optical reflectance of the swirls is related to a very thin surface phenomenon less than several decimeters thick not observable with x or s band radar secondly bright swirl material appears to be stratigraphically younger than a newly discovered impact melt flow at gerasimovich d this observation indicates that the swirls are capable of forming over timescales less than the age of the crater the mini rf data set also provides clues to the origin of the lunar swirls in at least one case the presence of an enhanced crustal magnetic field appears to be responsible for the preservation of a high albedo ejecta blanket around an otherwise degraded crater descartes c the degree of degradation of descartes c suggests it should not be optically bright yet it is this implies that the enhanced albedo is related to its location within a magnetic anomaly and hence supports an origin hypothesis that invokes interaction between the solar wind and the magnetic anomaly

mantle deformation in sikkim and adjoining himalaya evidences for a complex flow pattern abstract new measurements of azimuthal anisotropy within the himalayan collision zone and southern tibet obtained by applying the sks splitting technique to waveforms from 31 broadband seismic stations reveal significant variations in the strength and orientation of the fast axes stations in the sikkim himalaya show strong anisotropy south of main central thrust mct with delay times 1 s the fast polarization directions are nearly parallel to the strike of the himalaya mountain chain and vary consistently along the profile from 105 in the south to 130 in the north however in the adjacent nepal himalaya a predominance of plate motion related strain is observed at least up to the mct the western portion of southern tibet south of the indus tsangpo suture zone reveals characteristics of e w oriented anisotropy contrary to null anisotropy found in the eastern part the complex flow pattern revealed in the present study may be due a combination of basal shear resulting from plate motion and ductile flow along the collision front due to compression

inversion of teleseismic s particle motion for azimuthal anisotropy in the upper mantle a feasibility study summary we have developed a technique for the inversion of teleseismic s waveforms in terms of azimuthal anisotropy in the upper mantle we test different models of the earth upper mantle by transforming the observed horizontal components into a synthetic vertical component and comparing this with the observed vertical component the optimum model is found by minimizing the difference between the synthetic vertical component and the observed one using this method we explore the possibility of constraining the distribution of azimuthal anisotropy with depth we present examples of seismic observations where the data are clearly in favour of an anisotropic model these observations can be interpreted in terms of two anisotropic layers with different directions of fast velocity axes

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

relatively recent construction of the tien shan inferred from gps measurements of present day crustal deformation rates the tien shan a high seismically active intracontinental mountain belt 1 000 2 000 km north of the himalaya has grown as a result of india s collision with asia1 the crustal shortening 200 50 km refs 2 3 and thickening that gave rise to the tien shan accommodates only a small fraction of india s total penetration into asia 2 000 3 000km and the temporal relationship of deformation in this belt to the india asia collision remains unclear here we report geodetic measurements of the tien shan using the global positioning system gps that indicate that the current crustal shortening rate is nearly half of india s convergence rate with eurasia in this area4 we infer a total shortening rate for the tien shan of 20 mm yr 1 which is approximately twice that inferred previously from the extrapolation of slip rates in the holocene3 and earthquake induced displacements during this century5 suggesting that the rate of mountain building in this region has accelerated several fold since the onset of collision 50 55 myr ago6 7 if as we argue the current shortening rate can be extrapolated to geological timescales then our results suggest that most of the tien shan has been constructed during the past 10 myr perhaps in response to an increased horizontal force following an abrupt rise of the tibetan plateau8 9

ert gpr insar and tracer tests to characterize karst aquifer systems under urban areas the case of quebec city abstract urban infrastructures built over karst settings may be at risk of collapse due to hydro chemical erosion of underlying rock structures in such settings mapping cave networks and monitoring ground stability is important to assure civil safety and guide future infrastructure development decisions however no technique can directly and comprehensively map these hydrogeological features and monitor their stability the most reliable method to map a cave network is through speleological exploration which is not always possible due to restrictions narrow corridors passages or high water levels borehole drilling is expensive and is often only performed where the presence of karsts is suggested by other techniques numerous indirect and cost effective methods exist to map a karst flow system such as geophysics geodesy and tracer tests this paper presents the outcomes from a challenging application in quebec city canada where a multidisciplinary approach was designed to better understand the groundwater dynamics and cave paths two tracer tests in groundwater flowing through the cave system indicated that water flows along an approximately straight path from the sinking stream to the spring it also suggests the presence of a parallel flow path close to the one already partially mapped this observation was confirmed by combining ground penetrating radar gpr and electrical resistivity tomography ert techniques and ultimately by observing voids in several boreholes drilled close to the main cave path lowering the water levels at the suspected infiltration zone and inside the karst the infiltration cracks were identified and the hydraulic link between them was confirmed in fact almost no infiltration occurs into the karst system when the water level at the sinking stream drops below a threshold level finally sar interferometry insar using radarsat 2 images detected movements on few buildings located over a backfilled sinkhole intercepted by the karst system and confirmed the stability of the rest of the karst area the knowledge of the flow system described in this paper is used by policy makers to assure civil security of this densely populated area

upper mantle stratification by p and s receiver functions summary seismic stratification of the upper mantle is investigated by applying two complementary techniques to the records of the graefenberg array in southern germany the anisotropic p receiver function technique kosarev et al 1984 vinnik montagner 1996 is modified by using summary seismic events instead of individual events and different weighting functions instead of the same function for the harmonic angular analysis of the sv and t components of the pds phases the summary events provide better separation of the second azimuthal harmonic than the individual events the parameters of the second harmonics of sv and t thus evaluated should be similar if they reflect the effects of azimuthal anisotropy this can be used as a criterion to identify the anisotropy to detect the sdp phases and their azimuthal variations caused by azimuthal anisotropy we have developed a stacking technique which can be termed the s receiver function technique it includes axis rotation to separate interfering p and s arrivals determination of the principal m component of the s wave motion deconvolution of the p components of many recordings by their respective m components and stacking of the deconvolved p components with weights depending on the level of noise and the angle between the m direction and the backazimuth of the event both techniques yield consistent results for the graefenberg array as indicated by the p receiver functions the upper layer of the mantle between the moho and 80 km depth is anisotropic with dvs vs around 0 03 and the fast direction close to 20 clockwise from north the fast direction of anisotropy below this layer is around 110 the boundary between the upper and the lower anisotropic layers is manifested by the detectable pds and sdp converted phases shear wave splitting in sks is strongly dominated by azimuthal anisotropy in the lower layer asthenosphere

shear wave splitting and small scale convection in the continental upper mantle the deformation of the upper mantle beneath a collisional belt is key to the dynamics of the belt but this deformation is difficult to observe seismic azimuthal anisotropy manifested by shear wave splitting provides the best geophysical evidence of deformation in the upper mantle here we use observations of shear wave splitting to investigate deformation in the upper mantle beneath the tien shan in central asia we find that underneath most of the tien shan the fast direction of azimuthal anisotropy is roughly parallel to the axis of the belt but it deviates by nearly 90 where the upper mantle is anomalously hot the former relationship previously observed in other collisional belts seems to be usual for this environment the anomalous directions however provide evidence of a rising plume beneath the range suggesting more generally that the along strike flow of the mantle beneath collisional belts is a reflection of thermally driven convection

evidence for water ice on the moon results for anomalous polar craters from the lro mini rf imaging radar 1 the mini rf radar instrument on the lunar reconnaissance orbiter spacecraft mapped both lunar poles in two different rf wavelengths complete mapping at 12 6 cm s band and partial mapping at 4 2 cm x band in two look directions removing much of the ambiguity of previous earth and spacecraft based radar mapping of the moon s polar regions the poles are typical highland terrain showing expected values of radar cross section albedo and circular polarization ratio cpr most fresh craters display high values of cpr in and outside the crater rim the pattern of these cpr distributions is consistent with high levels of wavelength scale surface roughness associated with the presence of block fields impact melt flows and fallback breccia a different class of polar crater exhibits high cpr only in their interiors interiors that are both permanently dark and very cold less than 100 k application of scattering models developed previously suggests that these anomalously high cpr deposits exhibit behavior consistent with the presence of water ice if this interpretation is correct then both poles may contain several hundred million tons of water in the form of relatively clean ice all within the upper couple of meters of the lunar surface the existence of significant water ice deposits enables both long term human habitation of the moon and the creation of a permanent cislunar space transportation system based upon the harvest and use of lunar propellant