gravity field of the moon from the gravity recovery and interior laboratory grail mission spacecraft to spacecraft tracking observations from the gravity recovery and interior laboratory grail have been used to construct a gravitational field of the moon to spherical harmonic degree and order 420 the grail field reveals features not previously resolved including tectonic structures volcanic landforms basin rings crater central peaks and numerous simple craters from degrees 80 through 300 over 98 of the gravitational signature is associated with topography a result that reflects the preservation of crater relief in highly fractured crust the remaining 2 represents fine details of subsurface structure not previously resolved grail elucidates the role of impact bombardment in homogenizing the distribution of shallow density anomalies on terrestrial planetary bodies

global distribution of large lunar craters implications for resurfacing and impactor populations by using high resolution altimetric measurements of the moon we produced a catalog of all impact craters 20 kilometers in diameter on the lunar surface and analyzed their distribution and population characteristics the most densely cratered portion of the highlands reached a state of saturation equilibrium large impact events such as orientale basin locally modified the prebasin crater population to 2 basin radii from the basin center basins such as imbrium orientale and nectaris which are important stratigraphic markers in lunar history are temporally distinguishable on the basis of crater statistics the characteristics of pre and postmare crater populations support the hypothesis that there were two populations of impactors in early solar system history and that the transition occurred near the time of the orientale basin event

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

wind control of storm triggered shallow landslides 1 heavy rainstorms are a major control of shallow landsliding in mountainous areas the influence of three dimensional 3 d variability of precipitation is analyzed by coupling a fine resolution atmospheric model rams with a fine resolution topographic model dem to represent the 3 d precipitation flux generating the catastrophic flood that occurred in versilia central italy on 19 june 1996 matching of this flux with the observed scars and debris shows that 92 of the mass movements occurred where the normalized precipitation flux exceeds 0 80 and less then 2 where this is null these results give an insight of the detected role of exposure in explaining the spatial variability of observed landslides as emerging from multivariate statistical analysis the interaction of the wind driven precipitation field with topography is an important control of shallow landslides triggered by convective storms in upland catchments

magma ascent at floor fractured craters diagnoses the lithospheric stress state on the moon abstract on the moon floor fractured craters ffcs present evidence of horizontal crater centred magmatic intrusions crater floor uplift and moat formation indicate that these sill intrusions occur at shallow depths

gravitational signatures of lunar floor fractured craters lunar floor fractured craters are impact craters characterized by distinctive shallow floors crossed by important networks of fractures different scenarios have been proposed to explain their formations but recent studies showed that the intrusion of magma at depth below the crater floor is the most plausible explanation the intrusion of dense magma within the light upper most part of the lunar crust should have left a positive signature in the gravity field this study takes advantage of the unprecedented resolution of the lunar gravity field obtained from the nasa s gravity recovery and interior laboratory grail mission in combination with topographic data obtained from the lunar orbiter laser altimeter lola instrument to investigate the gravitational signatures of both normal and floor fractured craters despite the large variability in their gravitational signatures the floor fractured and normal craters in the highlands show significant differences the gravitational anomalies are significantly larger at floor fractured craters the anomaly amplitudes for floor fractured craters are in agreement with synthetic gravity anomalies based on the predicted intrusion shapes from a theoretical flow model our results are consistent with magmatic intrusions intruding a crust characterized by a 12 porosity and where the intrusion has no porosity similar studies have been carried out in the lunar maria and south pole aikten basin although the average gravitational signature of floor fractured craters is larger than at normal craters in these regions they cannot be distinguished statistically due to the small number of craters and the large variability of the anomalies in general a better characterization of the signal due solely to the initial impact crater is needed to isolate the magmatic intrusion signal and characterize the density contrast between the magma and crust

assessment of landslide occurrences in serra do mar mountain range using kinematic analyses due to its meteorological geological and geomorphological settings brazilian s atlantic coast have suffered severe landslide phenomena particularly along the cost of sao paulo rio de janeiro and santa catarina states studies have shown that these processes are complex and triggered by several factors however within the study area many landslide locations are placed on gneiss migmatitic terrain with pronounced geological discontinuities the objective of this paper is to assess landslide occurrences in serra do mar caraguatatuba sp and investigate by means of kinematic analysis how they correlate with foliation and fractures present on the rocks kinematic analysis is used to investigate which discontinuities are more favorable to landslides occurrence and their relationship with slope directions structural information and kinematic data models are used to evaluate cause effect relationship of landslide processes results show that dip slopes with ne sw direction have greatest potential for the occurrence of planar landslides on the other hand anti dip and cross dip slopes have a greater potential to develop wedge landslides rock weathering and fluid flux along foliation planes can intensify mass movement such effect is also seen in residual soil since they are able to preserve relict structures of the rock this study contributes to a better understanding of how geological structures preserved in tropical residual soils influence shallow landslides

application of lidar and discriminant analysis to determine landscape characteristics for different types of slope failures in heavily vegetated steep terrain horseshoe run watershed west virginia abstract a landslide inventory map was created for horseshoe run watershed west virginia using high resolution topographic data obtained from airborne lidar a total of 152 landslides were remotely mapped and classified as planar slides rotational slumps debris flows debris fans debris slides and active slopes based on morphologic characteristics interpreted from lidar derived shaded relief maps with field verification at several locations seven landscape variables were calculated for the watershed from the high resolution 0 5 m topographic data elevation slope angle slope aspect distance from roads distance from streams plan curvature and profile curvature statistical analyses were conducted to determine the mean and standard deviations for each variable and corresponding slope failure type discriminant analyses were conducted on the different types of failed slopes with a maximum 86 accuracy level to determine which landscape characteristics contribute to each type of landslide results from the discriminant analyses indicate that statistically significant differences exist between the failure classes mapped within the watershed and that slope angle slope aspect and landscape curvature are important variables influencing the type of process the results from this study have important implications for predicting where certain types of slope failures may occur based on landscape characteristics

the petrology and geochemistry of miller range 05035 a new lunar gabbroic meteorite miller range mil 05035 is a lunar gabbroic meteorite the mineralogy fe mn ratios in olivine and pyroxene bulk rock chemical composition and the bulk oxygen isotope values 17o 2 86 2 97 and 18o 5 47 5 71 are similar to those of other mare basalts and are taken as supporting evidence for a lunar origin for this meteorite the sample is dominated by pyroxene grains 54 61 by area mode of thin section along with large plagioclase feldspar 25 36 by mode and accessory quartz ilmenite spinel apatite and troilite the bulk rock major element composition of mil 05035 indicates that the sample has a very low ti vlt to low ti lunar heritage we measure bulk tio2 to be 0 9 wt and has low bulk incompatible trace element ite concentrations akin to samples from the vlt mare basalt suite to account for these geochemical characteristics we hypothesize that mil 05035 s parental melt was derived from a mantle region dominated by early cumulates of the magma ocean comprised principally of olivine and orthopyroxene mil 05035 is likely launch paired with the asuka 881757 and yamato 793169 basaltic lunar meteorites and the basaltic regolith breccia met 01210 this group of meteorites y a m m therefore may be a part of a stratigraphic column consisting of an upper regolith environment underlain by a coarsening downwards basalt lava flow

insights into mare basalt thicknesses on the moon from intrusive magmatism abstract magmatic intrusions preferentially spread along interfaces marked by rigidity and density contrasts thus the contact between a lunar mare and its substratum provides a preferential location for subsequent magmatic intrusions shallow intrusions that bend the overlying layer develop characteristic shapes that depend on their radius and on the overlying layer flexural wavelength and hence on their emplacement depth we characterize the topography of seven previously identified candidate intrusive domes located within different lunar maria using data from the lunar orbiter laser altimeter their topographic profiles compare very well with theoretical shapes from a model of magma flow below an elastic layer supporting their interpretation as intrusive features this comparison allows us to constrain their intrusion depths and hence the minimum mare thickness at these sites these new estimates are in the range 400 1900 m and are generally comparable to or thicker than previous estimates when available the largest thickness 1700 m is obtained next to the hortensius and kepler areas that are proposed to be the relicts of ancient volcanic shields

magnitude frequency characteristics and preparatory factors for spatial debris slide distribution in the northern faroe islands abstract the faroe islands in the north atlantic ocean are highly susceptible to debris avalanches and debris flows originating from debris slide activity in shallow colluvial soils to provide data for hazard and risk assessment of debris avalanches and debris flows this study aims at quantifying the magnitude and frequency of their debris slide origins as well as identifying which preparatory factors are responsible for the spatial debris slide distribution in the landscape for that purpose a debris slide inventory was generated from aerial photo interpretation api fieldwork and anecdotal sources covering a 159 km2 study area in the northern faroe islands a magnitude cumulative frequency mcf curve was derived to predict magnitude dependant debris slide frequencies while preparatory factors responsible for spatial debris slide distribution were quantified through gis supported discriminant function analysis dfa nine factors containing geological lithology dip geomorphological slope angle altitude aspect plan and profile curvature and land use infield outfield sheep density information were included in the multivariate analysis debris slides larger than 100 m2 with magnitude expressed as topographic scar area can be predicted from the power law function y 936 26x 1 277 r2 0 98 while a physical explanation is preferred for the roll over pattern of smaller slope failures the dfa is able to correctly classify app 70 of the modeled terrain units into their pre determined stable unstable groups preparatory factors responsible for the spatial debris slide distribution are aspect slope angle sheep density plan curvature and altitude while influence of the remaining factors is negligible

stratigraphic evidence for a pluvial phase between ca 8200 7100 ka from renella cave central italy a stratigraphic and chronological study of the upper level of renella cave apuan alps central italy reveals that two episodes of flowstone accumulation bracket a thick clastic layer deposited between ca 8 2 and 7 1 ka this layer which represents a period of enhanced cave flooding is substantially in phase with an interval of depleted oxygen isotope values previously recorded in a stalagmite from nearby corchia cave interpreted to have resulted from an increase in local precipitation these data confirm that during this period of time the region experienced relatively wetter conditions including an increase in high magnitude events capable of invading the higher passages of renella cave the timing of the clastic phase occurred when the eastern mediterranean experienced deposition of sapropel layer s1 which is thought to reflect the stagnation of sea water produced largely by enhanced flood activity along the nile in response to increased monsoon intensity in northern equatorial africa recent estimates suggest that s1 may have lasted from ca 10 8 to ca 6 1 ka cal bp combined evidence from renella and corchia cave indicates that the period corresponding to the wettest phase in the apuan alps was much shorter than this and suggests that there is no straightforward connection between increased advection of water vapour from the atlantic between 8 2 and 7 1 ka as recorded in the corchia and renella records and monsoon driven enhancement of nile discharge and s1 deposition in the eastern mediterranean

northwest africa 482 a crystalline impact melt breccia from the lunar highlands northwest africa 482 nwa 482 is a crystalline impact melt breccia from the moon with highlands affinities the recrystallized matrix and the clast population are both highly anorthositic clasts are all related to the ferroan anorthosite suite and include isolated plagioclase crystals and lithic anorthosites troctolites and spinel troctolites potassium rare earth element and phosphorus bearing kreep and mare lithologies are both absent constraining the source area ofthis meteorite to a highland terrain with little to no kreep component most likely on the far side of the moon glass is present in shock veins cutting through the sample and in several large melt pockets indicating a second impact event there are two separate events recorded in the 40ar 39ar system one at 3750 ma which completely reset the k ar system and one at 2400 ma which caused onlypartial degassing these events could represent respectively crystallization ofthe impact melt breccia and later formation of the glass or the formation of the glass and a later thermal event the terrestrial age of the meteorite is 8 6 1 3 ka this age corresponds well with the modest amount ofweathering in the rock in the form ofsecondaryphyllosilicates and carbonates based on terrestrial age and location lithology and chemistry nwa 482 is unique among known lunar meteorites

the donbas foldbelt its relationships with the uninverted donets segment of the dniepr donets basin ukraine abstract the donbas foldbelt df is a thrust faulted and folded inverted segment of the dniepr donets basin ddb it lies between the scythian and east european platforms north of the black sea and is conventionally thought to have formed in the early permian as part of the late palaeozoic hercynian uralian orogenic frame of cratonic europe the ddb itself formed as a result of late devonian intracratonic rifting and contains a thick up to 22 km late palaeozoic and mesozoic sedimentary succession the deformed strata preserved at the erosional surface of the df are mainly carboniferous the donets segment of the ddb displays mild inversion structures that are transitional to those in the df recently acquired regional seismic reflection data in the donets part of the ddb allow these structures to be imaged in the subsurface for the first time a widespread early permian unconformity occurring throughout the ddb is much more pronounced on its southern margin than on its northern one and appears to be related to profound uplift of the southern flank of the basin and the neighbouring ukrainian shield rather than to crustal shortening faults associated with the early permian unconformity are extensional in style gentle folds and other local structures in the southern flank and axis of the donets segment are mainly located in areas associated with early permian salt movements no significant development of compressional structures of early permian age can be seen in the seismic data where it is available in contrast there is ample evidence of latest cretaceous earliest tertiary compressional deformation in the ddb including the subsurface expression of structures along strike of the main folds of the df a review of geological evidence in the df also indicates that the main period of shortening that can be definitely constrained in time is latest cretaceous earliest tertiary the eastern part of the df records intense late triassic aged cimmerian deformation but none of clearly permian age it is tentatively concluded that the main phases of trans compressional tectonics forming the df were cimmerian and especially alpine rather than hercynian uralian

ancient igneous intrusions and early expansion of the moon revealed by grail gravity gradiometry the earliest history of the moon is poorly preserved in the surface geologic record due to the high flux of impactors but aspects of that history may be preserved in subsurface structures application of gravity gradiometry to observations by the gravity recovery and interior laboratory grail mission results in the identification of a population of linear gravity anomalies with lengths of hundreds of kilometers inversion of the gravity anomalies indicates elongated positive density anomalies that are interpreted to be ancient vertical tabular intrusions or dikes formed by magmatism in combination with extension of the lithosphere crosscutting relationships support a pre nectarian to nectarian age preceding the end of the heavy bombardment of the moon the distribution orientation and dimensions of the intrusions indicate a globally isotropic extensional stress state arising from an increase in the moon s radius by 0 6 to 4 9 kilometers early in lunar history consistent with predictions of thermal models

the formation of the south eastern part of the dniepr donets basin 2 d forward and reverse modelling taking into account post rift redeposition of syn rift salt abstract forward and reverse modelling of structure and stratigraphy has been used to investigate the syn rift late devonian and early post rift carboniferous evolution of the south eastern part of the dniepr donets basin ddb modelling was carried out with and without taking into consideration the withdrawal and surface extrusion of devonian salt during the formation of salt diapirs the great thickness of carboniferous deposits can be explained by the superimposed actions of three processes post rift thermal subsidence withdrawal of devonian salt from the mother layer during phases of salt diapir activity and regional subsidence of the east european platform the effects of other tectonic and or non tectonic processes are not required forward syn rift modelling using the flexural cantilever model of sedimentary basin formation predicts the total syn rift extension across the southeastern ddb to be approximately 65 km with a maximum stretching factor of 2 4 shallowing of the moho during the syn rift phase is estimated to be 15 km the present day moho after thermal subsidence and basin fill is predicted to be 4 6 km shallower than surrounding regions in the axial zone of the south eastern ddb the thickness of the devonian syn rift sequence may have reached 7 5 km by the end of the rift stage this is 3 3 5 km more than at present the thicknesses reduction is due to the outflow of devonian salt during post rift periods of halokinetic activity in the early visean the middle serpukhovian and in the early permian the withdrawal of salt from the mother layer produced additional accommodation space and up to 1 5 1 7 km of the total eventual thickness of the carboniferous sedimentary succession can be explained as a result of this

lunar floor fractured craters as magmatic intrusions geometry modes of emplacement associated tectonic and volcanic features and implications for gravity anomalies lunar floor fractured craters are a class of 170 lunar craters with anomalously shallow fractured floors two end member processes have been proposed for the floor formation viscous relaxation and subcrater magmatic intrusion and sill formation recent morphometric analysis with new lunar reconnaissance orbiter laser altimeter lola and image lroc data supports an origin related to shallow magmatic intrusion and uplift we find that the distribution and characteristics of the ffc population correlates strongly with crustal thickness and the predicted frequency distribution of overpressurization values of magmatic dikes for a typical nearside lunar crustal thickness dikes with high overpressurization values favor surface effusive eruptions medium values favor intrusion and sill formation and low values favor formation of solidified dikes concentrated lower in the crust we develop a model for this process make predictions for the morphologic morphometric volcanic and geophysical consequences of the process and then compare these predictions with the population of observed floor fractured craters in our model the process of magmatic intrusion and sill formation begins when a dike propagates vertically towards the surface as the dike encounters the underdense brecciated region beneath the crater the magmatic driving pressure is insufficient to continue vertical propagation but pressure in the stalled dike exceeds the local lithostatic pressure the dike then begins to propagate laterally forming a sill which does not propagate past the crater floor region because increased overburden pressure from the crater wall and rim crest pinch off the dike at this boundary the sill then continues to inflate further raising and fracturing the brittle crater floor when the intrusion diameter to intrusion depth ratio is smaller than a critical value the intrusion assumes a laccolith shape with a domed central region when the ratio exceeds a critical value the intrusion concentrates bending primarily at the periphery resulting in a flat tabular intrusion we predict that this process will result in concentric fractures over the region of greatest bending this location is close to the crater wall in large flat floored craters as observed in the crater humboldt and interior to the crater over the domed floor in smaller craters as observed in the crater vitello a variety of volcanic features are predicted to be associated with the solidification and degassing of the intrusion these include 1 surface lava flows associated with concentric fractures e g in the crater humboldt 2 vents with no associated pyroclastic material from the deflation of under pressurized magmatic foam e g the crater damoiseau and 3 vents with associated pyroclastic deposits from vulcanian eruptions of highly pressurized magmatic foam e g the crater alphonsus the intrusion of basaltic magma beneath the crater is predicted to contribute a positive component to the bouguer gravity anomaly we assess the predicted bouguer anomalies associated with ffcs and outline a process for their future interpretation we conclude that our proposed mechanism serves as a viable formation process for ffcs and accurately predicts numerous morphologic morphometric and geophysical features associated with ffcs these predictions can be further tested using grail gravity recovery and interior laboratory data

style and timing of salt tectonics in the dniepr donets basin ukraine implications for triggering and driving mechanisms of salt movement in sedimentary basins abstract the ukrainian dniepr donets basin ddb is a late palaeozoic intracratonic rift basin with sedimentary thicknesses up to 19 km displaying the effects of salt tectonics during its entire history of formation from late devonian rifting to the tertiary hundreds of concordant and discordant salt structures formed during this time it is demonstrated in this paper that the variety of styles of salt structure formation in the ddb provide important constraints on understanding the triggering and driving mechanisms of salt kinematics in sedimentary basins in general salt movement in the ddb began during the devonian syn rift phase of basin development and exerted controls on the later distribution of salt structures though the geometry of basement faults is not directly responsible for the regular spacing of salt structures post rift salt movements in the ddb occurred episodically episodes of salt movement were triggered by tectonic events specifically two extensional events during the carboniferous an extensional reactivation at the end of carboniferous earliest permian and a compressional event at the end of the cretaceous extensional events that induced salt movement were thick skinned i e basement involved in deformation rather than thin skinned most overburden deformation related to salt movements is ductile regardless of sedimentary bulk lithology and degree of diagenesis while the deformation of sedimentary cover in areas where salt is absent is mainly brittle this implies that the presence of salt changes the predominant mode of deformation of overlying sedimentary rocks episodes of salt movement lasted longer than the periods of active tectonics that initiated them buoyancy erosion and differential loading all played a role in driving halokinesis once tectonic forces had pushed the salt overburden system into disequilibrium among these factors erosion of overburden above growing salt structures acted as a key self renewing force for development of salt diapirs very high sedimentation rates related to high post rift tectonic subsidence rates particularly during the carboniferous were able to bury diapirs and to load salt bodies such that buoyancy erosion and differential loading forces eventually became insufficient to continue driving diapirism until the system was perturbed by an ensuing tectonic event in contrast some salt anticlines and diapirs developed continuously during the entire mesozoic because of much reduced tectonic subsidence rates and sedimentation supply during this time however a lower permian salt series and overhangs of buried diapirs played an important role in preventing overburden piercing and fracturing during the mesozoic and specifically during the late cretaceous salt diapirism phase

the sculptured hills of the taurus highlands implications for the relative age of serenitatis basin chronologies and the cratering history of the moon 1 new images from the lunar reconnaissance orbiter camera show the distribution and geological relations of the sculptured hills a geological unit widespread in the highlands between the serenitatis and crisium basins the sculptured hills shows knobby undulating radially textured and plains like morphologies and in many places is indistinguishable from the similarly knobby alpes formation a facies of ejecta from the imbrium basin the new lroc image data show that the sculptured hills in the taurus highlands is imbrium ejecta and not directly related to the formation of the serenitatis basin this occurrence and the geological relations of this unit suggests that the apollo 17 impact melts may not be not samples of the serenitatis basin forming impact leaving their provenance undetermined and origin unexplained if the apollo 17 melt rocks are serenitatis impact melt up to half of the basin and large crater population of the moon was created within a 30 ma interval around 3 8 ga in a global impact cataclysm either interpretation significantly changes our view of the impact process and history of the earth moon system

ring faults and ring dikes around the orientale basin on the moon the orientale basin is the youngest and best preserved multiring impact basin on the moon having experienced only modest modification by subsequent impacts and volcanism orientale is often treated as the type example of a multiring basin with three prominent rings outside of the inner depression the inner rook montes the outer rook montes and the cordillera here we use gravity data from nasa s gravity recovery and interior laboratory grail mission to reveal the subsurface structure of orientale and its ring system gradients of the gravity data reveal a continuous ring dike intruded into the outer rook along the plane of the fault associated with the ring scarp the volume of this ring dike is 18 times greater than the volume of all extrusive mare deposits associated with the basin the gravity gradient signature of the cordillera ring indicates an offset along the fault across a shallow density interface interpreted to be the base of the low density ejecta blanket both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent inner rook ring at the surface models of the deep basin structure show inflections along the crust mantle interface at both the outer rook and cordillera rings indicating that the basin ring faults extend from the surface to at least the base of the crust fault dips range from 13 22 for the cordillera fault in the northeastern quadrant to 90 for the outer rook in the northwestern quadrant the fault dips for both outer rings are lowest in the northeast possibly due to the effects of either the direction of projectile motion or regional gradients in pre impact crustal thickness similar ring dikes and ring faults are observed around the majority of lunar basins

modelling of the initiation of rainfall induced debris flows in the cardoso basin apuan alps italy abstract a case study is being carried out in relation to the event of june 19 1996 when an intense rainstorm hit the cardoso area in the apuan alps italy the catastrophe triggered several gravitational movements mainly characterized by soil slip debris flows a dataset coming from field and laboratory surveys allowed a complete parameterization of the event and consequently the realization of a physically based dynamic model related to the initiation of the rainfall induced landslides the aim of the study is to analyze the processes involved in the light of the modelling results and to assess the spatio temporal activity of the landslides both in terms of location of the triggering sites and of determination of the critical rainfall conditions the critical rainfall input thresholds obtained with a deterministic approach are then compared with the thresholds obtained by an empirical analysis of the main rainfall events occurred in the southern apuan area in the period from 1975 to 2002

small scale density variations in the lunar crust revealed by grail abstract data from the gravity recovery and interior laboratory grail mission have revealed that 98 of the power of the gravity signal of the moon at high spherical harmonic degrees correlates with the topography the remaining 2 of the signal which cannot be explained by topography contains information about density variations within the crust these high degree bouguer gravity anomalies are likely caused by small scale 10 s of km shallow density variations here we use gravity inversions to model the small scale three dimensional variations in the density of the lunar crust inversion results from three non descript areas yield shallow density variations in the range of 100 200 kg m 3 three end member scenarios of variations in porosity intrusions into the crust and variations in bulk crustal composition were tested as possible sources of the density variations we find that the density anomalies can be caused entirely by changes in porosity characteristics of density anomalies in the south pole aitken basin also support porosity as a primary source of these variations mafic intrusions into the crust could explain many but not all of the anomalies additionally variations in crustal composition revealed by spectral data could only explain a small fraction of the density anomalies nevertheless all three sources of density variations likely contribute collectively results from this study of grail gravity data combined with other studies of remote sensing data and lunar samples show that the lunar crust exhibits variations in density by 10 over scales ranging from centimeters to 100 s of kilometers

the mineralogy of late stage lunar volcanism as observed by the moon mineralogy mapper on chandrayaan 1 1 the last major phases of lunar volcanism produced spectrally unique high titanium basalts on the western nearside of the moon the moon mineralogy mapper m3 on chandrayaan 1 has provided detailed measurements of these basalts at spatial and spectral resolutions necessary for mineralogical interpretation and mapping of distinct compositional units the m3 imaging spectrometer acquired data in 85 spectral bands from 430 to 3000 nm at 140 to 280 m pixel in its global mapping mode during the first half of 2009 reflectance data of several key sites in the western maria were also acquired at higher spatial and spectral resolutions using m3 s target mode prior to the end of the chandrayaan 1 mission these new observations confirm that both fresh craters and mare soils within the western high ti basalts display strong 1 m and weak 2 m absorptions consistent with olivine rich basaltic compositions the inferred abundance of olivine is observed to correlate with stratigraphic sequence across different mare regions and absolute ages the apparent stratigraphic evolution and fe rich compositions of these basalts as a whole suggest an origin from evolved residual melts rather than through the assimilation of more primitive olivine rich sources mare deposits with spectral properties similar to these late stage high ti basalts appear to be very limited outside the procellarum imbrium region of the moon and where present appear to occur as small areas of late stage regional volcanism detailed analyses of these new data and supporting measurements are in progress to provide further constraints on the mineralogy olivine abundance and compositions of these final products of lunar volcanism and the nature and evolution of their source regions

characterising the spatial distribution frequency and geomorphic controls on landslide occurrence molise italy abstract an 815 km2 area in molise central italy was used as a natural laboratory to characterise the lithological topographic and fluvial controls on the spatial distribution and frequency of active landslides in temperate climates the study area is part of the central apennines fold and thrust belt and is characterised by the presence of a tectonic melange of scaly clays known as argille varicolori as well as more competent limestone and sandstone units the area has been subjected to a cumulative stream incision of up to 400 m since the mid pleistocene the landslide inventory was developed by combining satellite image interpretation and existing data sets ground truthed in the field statistical analysis of the inventory data demonstrates that the coupling between landslide occurrence in the area and lithology is strong with landslides occurring 3 10 times more frequently where the mechanically weak argille varicolori scaly clays outcrops compared to other lithologies analysis of the relationship between landslide occurrence and hillslope gradients shows that 50 of all landslides occur on slopes between 10 and 15 despite this interval representing only 30 of hillslope gradients in the study area these results demonstrate the major control that the properties of the regionally significant argille varicolori have on landslide occurrence in the area directly and through their control on hillslope gradients additionally our results show that more than 50 of the landslides occur at a distance of

susceptibility assessments of shallow earthflows triggered by heavy rainfall at three catchments by logistic regression analyses abstract sometimes regional meteorological anomalies trigger different types of mass movements in may 1998 the western black sea region of turkey experienced such a meteorological anomaly numerous residential and agricultural areas and engineering lifelines were buried under the flood waters besides the reactivation of many previously delineated landslides thousands of small scale landslides mostly the earthflow type occurred all over the region the earthflows were mainly developed in flysch type units which have already presented high landslide concentrations in this study three different catchments namely agustu egerci and kelemen were selected because they have the most landslide prone geological units of the region the purposes of the present study are to put forward the spatial distributions of the shallow earthflows triggered to describe the possible factors conditioning the earthflows and to produce the shallow earthflow susceptibility maps of the three catchments the unique condition units ucu were employed during the production of susceptibility maps and during statistical analyses the unique condition units numbered 4052 for the agustu catchment 13 241 for the egerci catchment and 12 314 for the kelemen catchment the earthflow intensity is the highest in the agustu catchment 0 038 flow ucu and lowest in the egerci catchment 0 0035 flow ucu logistic regression analyses were also employed however during the analyses some difficulties were encountered to overcome the difficulties a series of sensitivity analyses were performed based on some decision rules introduced in the present study considering the decision rules the proper ratios of ucu free from earthflow 0 ucu including the earthflow 1 for the agustu egerci and kelemen catchments were obtained as 3 6 and 5 respectively also a chart for the proper ratio selection was developed the regression equations from the selected ratios were then applied to the entire catchment and the earthflow susceptibility maps were produced the landslide susceptibility maps revealed that 15 of the agustu catchment 8 of the egerci catchment and 7 of the kelemen catchment have very high earthflow susceptibility and most of the earthflows triggered by the may 1998 meteorological event were found in the very high susceptibility zones

grail identified gravity anomalies in oceanus procellarum insight into subsurface impact and magmatic structures on the moon abstract four quasi circular positive bouguer gravity anomalies pbgas that are similar in diameter 90 190 km and gravitational amplitude 140 mgal contrast are identified within the central oceanus procellarum region of the moon these spatially associated pbgas are located south of aristarchus plateau north of flamsteed crater and two are within the marius hills volcanic complex north and south each is characterized by distinct surface geologic features suggestive of ancient impact craters and or volcanic plutonic activity here we combine geologic analyses with forward modeling of high resolution gravity data from the gravity recovery and interior laboratory grail mission in order to constrain the subsurface structures that contribute to these four pbgas the grail data presented here at spherical harmonic degrees 6 660 permit higher resolution analyses of these anomalies than previously reported and reveal new information about subsurface structures specifically we find that the amplitudes of the four pbgas cannot be explained solely by mare flooded craters as suggested in previous work an additional density contrast is required to explain the high amplitude of the pbgas for northern flamsteed 190 km diameter the additional density contrast may be provided by impact related mantle uplift if the local crust has a density 2800 kg m3 then 7 km of uplift is required for this anomaly although less uplift is required if the local crust has a lower mean density of 2500 kg m3 for the northern and southern marius hills anomalies the additional density contrast is consistent with the presence of a crustal complex of vertical dikes that occupies up to 50 of the regionally thin crust the structure of southern aristarchus plateau 90 km diameter an anomaly with crater related topographic structures remains ambiguous based on the relatively small size of the anomaly we do not favor mantle uplift however understanding mantle response in a region of especially thin crust needs to be better resolved it is more likely that this anomaly is due to subsurface magmatic material given the abundance of volcanic material in the surrounding region overall the four pbgas analyzed here are important in understanding the impact and volcanic plutonic history of the moon specifically in a region of thin crust and elevated temperatures characteristic of the procellarum kreep terrane

grail gravity constraints on the vertical and lateral density structure of the lunar crust we analyzed data from the gravity recovery and interior laboratory grail mission using a localized admittance approach to map out spatial variations in the vertical density structure of the lunar crust mare regions are characterized by a distinct decrease in density with depth while the farside is characterized by an increase in density with depth at an average gradient of 35 kg m 3 km 1 and typical surface porosities of at least 20 the apollo 12 and 14 landing site region has a similar density structure to the farside permitting a comparison with seismic velocity profiles the interior of the south pole aitken sp a impact basin appears distinct with a near surface low density porous layer 2 3 times thinner than the rest of the farside this result suggests that redistribution of material during the large sp a impact likely played a major role in sculpting the lunar crust

the influence of the geological and geomorphological settings on shallow landslides an example in a temperate climate environment the june 19 1996 event in northwestern tuscany italy on june 19 1996 an extremely heavy rainstorm hit a restricted area in the apuan alps northwestern tuscany italy its max intensity concentrated over an area of about 150 km2 astride the apuan chain where 474 mm was recorded in about 12 h 21 of the mean annual precipitation with an intensity up to 158 mm h the storm caused floods and hundreds of landslides and debris flows which produced huge damage hundreds of millions of euros partially destroyed villages and killed 14 people this paper reports the results obtained from a detailed field survey and aerial view interpretation in the most severely involved area 647 main landslides were investigated mapped and related to the geologic geomorphic and vegetational factors of the source areas this was in order to define the influence of these factors and contribute to an evaluation of the landslide hazard in the study area an assessment was also made of the total area and volume of material mobilised by landsliding the study area about 46 km2 wide includes three typically mountainous basins characterised by narrow deep cut valleys and steep slopes where many rock types outcrop most of the landslides were shallow and linear referable to complex earth and debris translational slide which quickly developed into flow soil slip debris flow usually they involved colluvium and started in hollows underlain by metamorphic rock metasandstone and phyllite often dipping downslope therefore bedrock lithology and impermeability appeared to be important factors in the localisation of the landslide phenomena the investigation of the geomorphic and land use features in the source areas also frequently highlighted a rectilinear profile of the slope a high slope gradient 31 45 and dense chestnut wood cover in the area about 985 000 m2 2 1 of 46 km2 was affected by landsliding and about 700 000 m2 of this area was covered by chestnut forest the landslides removed about 7000 trees the volume of mobilised material was about 1 360 000 m3 about 220 000 m3 remained on the slopes while the rest poured into the streams in addition about 945 000 m3 was mobilised by the torrential erosion in the riverbeds

structural features and evolution of the dniepr donets basin ukraine from regional seismic reflection profiles abstract a set of regional multichannel seismic reflection profiles crossing the dniepr donets dd basin in ukraine 100 200 km long and with a spacing of 10 15 km along strike illuminates the structure of the whole sedimentary cover the rift filled with pre and syn rift devonian sequences and overlain with post rift carboniferous permian mesozoic and palaeogene fill is clearly seen on all sections a basement layer previously identified as a riphean rift succession by refraction seismic studies constitutes in the main strata of the devonian and early carboniferous successions the structure of the rift is characterised by large scale rotational fault blocks and half grabens carried by basin parallel to normal marginal faults or by major horst blocks the total thickness of the devonian and younger succession is up to 19 km in the study area post rift carboniferous and mesozoic sediments cover the rift flanks and increase in thickness towards the rift axis and to the southeast the cumulative thickness of the carboniferous succession alone reaches 11 km with the maximum depth of their base at about 15 km major post rift tectonic events took place at the end of early visean in the middle of serpukhovian in permian times and between the mesozoic and cenozoic tectonic reactivations during carboniferous and early permian times were most pronounced in the southeastern part of the dd basin while they were least pronounced in the northwestern part of the basin merging with the pripyat trough where they are barely observed the most active development of salt structures and stocks corresponds with the periods of tectonic reactivation

elliptical structure of the lunar south pole aitken basin abstract the south pole aitken basin sp a is the largest and oldest basin on the moon the basin has usually been interpreted to exhibit a degraded circular structure but here we demonstrate that the topography iron and thorium signatures of the basin are well described by ellipses with axes measuring 2400 by 2050 km and centered at 53 191 e topography abundances of iron thorium and the distribution of mare basalts are all elevated in the northern halves of the ellipses we also identify an outer topographic ellipse whose semiminor axis scales with the main topographic ellipse by approximately 2 taken together these data imply that the basin was created by an oblique impact along an azimuth of approximately 19 measured counterclockwise from longitude 191 e the geometry of the elevated central farside topography surrounding sp a suggests that it predates the impact the elliptical ring structures of sp a and their scaling relationships will help to understand the formation of large and elliptical basins elsewhere in the solar system this refined basin shape will also inform local geology geochemistry and geophysics of the region

lunar floor fractured craters evidence for viscous relaxation of crater topography in this paper we evaluate quantitatively the hypothesis that topographic modification of floor fractured craters on the moon was accomplished predominantly by viscous relaxation adopting the simple assumption that the moon may be modeled as having a uniform newtonian viscosity we compare the observed topographic profiles for a number of floor fractured craters with the profiles predicted from the viscous relaxation of topography of fresh craters of similar diameter despite the simplicity of the rheological model the comparison is quite good the floor uplift the rim subsidence and the apparent subsidence outside the rim for the several floor fractured craters considered are well matched by the viscous relaxation hypothesis floor fractures while indicating that a purely viscous model is not strictly valid can be explained by the effects of isostatic adjustment on a thin brittle lithosphere the association of many floor fractured craters with impact basins and with the time of mare volcanism can be understood in terms of a pronounced acceleration of crater relaxation in local regions of anomalously high near surface temperatures and therefore of low effective viscosity and thin lithosphere the quantitative extent of relaxation of floor fractured craters can be interpreted in terms of a limited time interval of substantial relaxation for each crater that time interval ended for each crater after local cooling had been sufficient for the viscosity to rise for the lithosphere to thicken and for the present topographic relief to be frozen in thus viscous relaxation is a viable hypothesis to explain the topographic profiles of a number of lunar floor fractured craters and the extent of viscous relaxation of crater topography may serve as a tool to map lateral and temporal variations in the shallow thermal structure of the moon and of other planets and satellites

a gis based automated procedure for landslide susceptibility mapping by the conditional analysis method the baganza valley case study italian northern apennines among the many gis based multivariate statistical methods for landslide susceptibility zonation the so called conditional analysis method holds a special place for its conceptual simplicity in fact in this method landslide susceptibility is simply expressed as landslide density in correspondence with different combinations of instability factor classes to overcome the operational complexity connected to the long tedious and error prone sequence of commands required by the procedure a shell script mainly based on the grass gis was created the script starting from a landslide inventory map and a number of factor maps automatically carries out the whole procedure resulting in the construction of a map with five landslide susceptibility classes a validation procedure allows to assess the reliability of the resulting model while the simple mean deviation of the density values in the factor class combinations helps to evaluate the goodness of landslide density distribution the procedure was applied to a relatively small basin 167 km2 in the italian northern apennines considering three landslide types namely rotational slides flows and complex landslides for a total of 1 137 landslides and five factors namely lithology slope angle and aspect elevation and slope bedding relations the analysis of the resulting 31 different models obtained combining the five factors confirms the role of lithology slope angle and slope bedding relations in influencing slope stability

topographic characterization of lunar complex craters 1 we use lunar orbiter laser altimeter topography data to revisit the depth d diameter d and central peak height hcp diameter relationships for fresh complex lunar craters we assembled a data set of young craters with d 15 km and ensured the craters were unmodified and fresh using lunar reconnaissance orbiter wide angle camera images we used lunar orbiter laser altimeter gridded data to determine the rim to floor crater depths as well as the height of the central peak above the crater floor we established power law d d and hcp d relationships for complex craters on mare and highlands terrain our results indicate that craters on highland terrain are on average deeper and have higher central peaks than craters on mare terrain furthermore we find that the crater depths for both mare and highlands craters are significantly deeper than previously reported this likely reflects the inclusion of transitional craters and or older and or modified craters in previous work as well as the limitations of the stereophotogrammetric and shadow length data sets used in those studies there is substantial variability in the depths and the central peak heights for craters in a given diameter range we suggest that the differences in mean d and hcp as a function of crater diameter for highlands and mare craters result from differences in bulk physical properties of the terrain types whereas the variability in d and hcp at a given diameter may reflect variations in impactor properties and impact parameters

application of radar data to modeling rainfall induced landslides many shallow landslides are triggered by heavy rainfall previous studies of landslide modeling have been hampered by the scarcity of rain gauges to adequately depict the spatial variability of rainfall conditions triggering landslides this study simulates the efficiency of the critical rainfall model for landslide prediction in a mountainous watershed with inputs of different rainfall estimates associated with a typhoon tropical cyclone event doppler radar data at a spatial resolution of 1 km and measurements from six gauging stations provide the sources for rainfall estimates inverse distance weighted splines and kriging are the interpolation methods for gauged rainfall estimates a comparison of the simulation outputs shows that the model using radar rainfall estimates has a better performance than those using gauged rainfall estimates in predicting both landslides and stable areas in light of the results this paper also discusses the validity of the critical rainfall model for landslides in relation to its rainfall input and steady state hydrological assumption

testing the viability of topographic relaxation as a mechanism for the formation of lunar floor fractured craters historically two modes of origin for lunar floor fractured craters have been proposed subcrater laccolith emplacement and topographic relaxation to test the viability of the topographic relaxation model we employ an elastoviscoplastic finite element model and ductile rheology measurements of a devolatilized terrestrial diabase an analog to lunar crustal materials trials were run under two situations 1 under extreme conditions e g high heat flow to determine the maximum degree of relaxation that the model can accommodate and 2 under more nominal conditions in order to resolve how much relaxation can be expected to occur under more plausible lunar conditions we find that in the extreme case topographic relaxation is a viable means only for explaining the observed shallowing of the largest floor fractured craters 100 km in diameter results from the less extreme case demonstrate that lunar materials are simply too rigid to experience degrees of relaxation as large as those observed in the floor fractured crater population these results indicate that topographic relaxation is not the primary mechanism for the formation of floor fractured craters because the topographic relaxation model does not apply for the vast majority of floor fractured craters i e those with diameters less than 60 km we conclude that the laccolith intrusion model is a more viable alternative

the origin of lunar mascon basins high resolution gravity data from the gravity recovery and interior laboratory spacecraft have clarified the origin of lunar mass concentrations mascons free air gravity anomalies over lunar impact basins display bull s eye patterns consisting of a central positive mascon anomaly a surrounding negative collar and a positive outer annulus we show that this pattern results from impact basin excavation and collapse followed by isostatic adjustment and cooling and contraction of a voluminous melt pool we used a hydrocode to simulate the impact and a self consistent finite element model to simulate the subsequent viscoelastic relaxation and cooling the primary parameters controlling the modeled gravity signatures of mascon basins are the impactor energy the lunar thermal gradient at the time of impact the crustal thickness and the extent of volcanic fill

ai based identification of low frequency debris flow catchments in the bailong river basin china abstract debris flow is a major geohazard in mountainous regions and poses a significant threat to life and property the damage caused by debris flows have increased with the expansion of human settlements and activity into the mountainous regions of china in regards to risks from debris flows previously unrecognized low frequency debris flow catchments constitute an especially significant threat according to our investigation only about 500 catchments have debris flow records in 2000 catchments of bailong river basin the main purpose of this paper is to introduce a new methodology using artificial intelligence ai that can simultaneously input parameters related to geomorphological conditions and material conditions to better distinguish low frequency debris flow catchments lfds from medium high frequency debris flow catchments mhfds a total of 449 prototypical debris flow catchments 15 parameters and 9 commonly used learning machines were used to build identification models debris flow catchments are divided into 4 cases lo1 lo4 based on different sample ratios of lfds and mhfds which are input into each classifier one by one based on model evaluation the chaid model in the case lo2 performs best which only uses five parameters formation lithology index land use index vegetation coverage index drainage density and landslide density index to predict lfds the results indicate that lfds are mainly distributed in areas with less landslide distribution and better vegetation coverage compared with mhfds however the distribution of lfds is concentrated on fli formation lithology index 4 which is the weak lithology area the tree classifier seems to be better at classifying fluvial processes the model developed in this paper can help us quickly find lfds in similar areas and help to assess the risk of debris flows

gravitational search for cryptovolcanism on the moon evidence for large volumes of early igneous activity abstract we define lunar cryptovolcanism as volcanic deposits on the moon hidden by overlying material notably cryptovolcanism includes both cryptomaria subsurface extrusive basaltic deposits that are obscured by overlying higher albedo basin and crater ejecta and earlier candidate extrusives such as the mg suite knowledge of the volume and extent of cryptovolcanism is necessary for a comprehensive understanding of lunar volcanic history particularly in early pre 3 8 ga epochs when abundant impact craters and basins obscured surface volcanic deposits by lateral emplacement of ejecta we use gravity recovery and interior laboratory grail gravity and lunar orbiter laser altimeter lola topography data to construct maps of the moon s positive bouguer and isostatic gravity anomalies and explore the possibility that these features are due to mass excesses associated with cryptovolcanism by cross referencing the regions with geologic data such as dark halo craters we model the potential cryptovolcanic deposits as buried high density rectangular prisms at depth in the upper crust and find a volume of candidate buried cryptovolcanism between 0 4 10 6 km 3 and 4 8 10 6 km 3 depending on assumptions about density and crustal compensation state these candidate deposits correspond to a surface area of between 0 50 10 6 km 2 and 1 14 10 6 km 2 which would increase the amount of the lunar surface containing volcanic deposits from 16 6 to between 17 9 and 19 5 the inferred volume of cryptovolcanism is comparable to the smallest estimates of the volume of visible mare basalts and up to 50 of the largest estimates the high resolution grail and lola observations thus would collectively indicate that early pre 3 8 ga lunar volcanism is an important element of lunar thermal evolution alternatively the buried material could represent the presence of intrusive mg suite sills or plutons

relationship between groundwater flow estimated by soil temperature and slope failures caused by heavy rainfall shikoku island southwestern japan most of the slope failure disasters in a humid area such as that of japan are caused by heavy rain however even for the case of heavy rainfall that occurs once in every 10 years total area of slope failures seldom exceeds 10 of a watershed from this background we focused on the vein like groundwater flows that increase pore water pressure and clarified the relationship between distributions of slope failures and groundwater veins in this study a 1 m depth ground temperature survey and water chemistry analyses at springs and boreholes were conducted in zentoku area of shikoku island southwestern japan to grasp the distribution of groundwater veins and their sources subsequently slope stability was analyzed to investigate the relationship between groundwater veins and slope failures at study sites these results lead to the following conclusions the slope failures appear to concentrate around shallow groundwater veins and groundwater veins rising from deep layers this means that slope failures caused by these groundwater veins in addition to rainfall two types of groundwater originate in the deep layers one has short storage time as indicated by the fact that dissolved substances are low the other is stored for a lengthy period as noted by a high concentration of dissolved substances by combining the results of stability analyses and distribution of groundwater veins it is suggested that prediction of zones with high potential for slope failure can be more accurate

landslides triggered by the 7 august 2009 typhoon morakot in southern taiwan abstract landslides triggered by typhoon morakot with an area over 576 m2 were mapped from formosat 2 images recognition and calculation of the number and area of landslides show that at least 22 705 landslides with a total area of 274 km2 were recognized in the 7811 km2 study area among these landslides 17 417 with a total area of 150 km2 are recognized as new ones and 5288 with a total area of 124 km2 are classified as enlarged from pre existing ones out of the 22 705 landslides there were 22 221 recognized with an area smaller than 10 ha 298 recognized in the range of 10 to 20 ha twenty two landslides with an area of over 60 ha have also been identified and the total area of these landslides is 20 km2 which is equal to 7 37 of the total landslide area with respect to exposed rock type the landslides mainly occurred in eocene miocene slate and miocene sandstone and shale in addition morakot induced landslides mainly occurred in areas with cumulative precipitation in the range of 800 to 2600 mm and the magnitude of landslide concentration is roughly linearly proportional to the amount of cumulative rainfall

diversity of basaltic lunar volcanism associated with buried impact structures implications for intrusive and extrusive events abstract relatively denser basalt infilling and the upward displacement of the crust mantle interface are thought to be contributing factors for the quasi circular mass anomalies for buried impact craters in the lunar maria imagery and gravity observations from the lunar reconnaissance orbiter lro and dual gravity recovery and interior laboratory grail missions have identified 10 partially or fully buried impact structures where diversity of observable basaltic mare volcanism exists with a detailed investigation of the characteristics of associated volcanic landforms we describe their spatial distribution relationship with respect to the subsurface tectonic structure of complex impact craters and propose possible models for the igneous processes which may take advantage of crater related zones of weakness and enable magmas to reach the surface we conclude that the lunar crust having been fractured and reworked extensively by cratering facilitates substance and energy exchange between different lunar systems an effect modulated by tectonic activities both at global and regional scales in addition we propose that the intrusion caused contribution to gravity anomalies should be considered in future studies although this is commonly obscured by other physical factors such as mantle uplift and basalt load

a model for the dynamics of crater centered intrusion application to lunar floor fractured craters lunar floor fractured craters are a class of craters modified by post impact mechanisms they are defined by distinctive shallow floors that are convex or plate like sometimes with a wide floor moat bordering the wall region radial concentric and polygonal floor fractures suggest an endogenous process of modification two mechanisms have been proposed to account for such deformations viscous relaxation and spreading of a magma intrusion at depth below the crater to test the second assumption and bring more constraints on the intrusion process we develop a model for the dynamics of magma spreading below an elastic overlying layer with a crater like topography as predicted in earlier more qualitative studies the increase in lithostatic pressure at the crater wall zone prevents the intrusion from spreading laterally leading to the thickening of the intrusion additionally our model shows that the final crater floor appearance after the uplift which can be convex or flat with or without a circular moat bordering the wall zone depends on the elastic thickness of the layer overlying the intrusion and on the crater size our model provides a simple formula to derive the elastic thickness of the overlying layer hence a minimum estimate for the intrusion depth finally our model suggests that crust redistribution by cratering must have controlled magma ascent below most of these craters

potential anomalies on a sphere applications to the thickness of the lunar crust a new technique for calculating potential anomalies on a sphere due to finite amplitude relief has been developed we show that by raising the topography to the nth power and expanding this field into spherical harmonics potential anomalies due to topography on spherical density interfaces can be computed to arbitrary precision using a filter for downward continuing the bouguer anomaly we have computed a variety of crustal thickness maps for the moon assuming both a homogeneous as well as a dual layered crust the crustal thickness maps for the homogeneous model give plausible results but this model is not consistent with the seismic data petrologic evidence and geoid to topography ratios all of which suggest some form of crustal stratification several dual layered models were investigated and it was found that only models with both upper and lower crustal thickness variations could satisfy the gravity and topography data these models predict that the entire upper crust has been excavated beneath the major nearside multiring basins additionally significant amounts of lower crustal material was excavated from these basins especially beneath crisium this model also predicts that mantle material should not have been excavated during the south pole aitken basin forming event and that lower crustal material should be exposed at the surface in this basin

the density and porosity of lunar rocks 1 accurate lunar rock densities are necessary for constructing gravity models of the moon s crust and lithosphere most apollo era density measurements have errors of 2 5 or more and few include porosity measurements we report new density and porosity measurements using the bead method and helium pycnometry for 6 apollo samples and 7 lunar meteorites with typical grain density uncertainties of 10 30 kg m 3 0 3 0 9 and porosity uncertainties of 1 3 comparison between igneous grain densities and normative mineral densities show that these uncertainties are realistic and that the helium fully penetrates the pore space basalt grain densities are a strong function of composition varying over at least 3270 kg m 3 high aluminum basalt to 3460 kg m 3 high titanium basalt feldspathic highland crust has a bulk density of 2200 2600 kg m 3 and porosity of 10 20 impact basin ejecta has a bulk density of 2350 2600 kg m 3 and porosity of 20

observational constraints on the identification of shallow lunar magmatism insights from floor fractured craters abstract floor fractured craters are a class of lunar crater hypothesized to form in response to the emplacement of a shallow magmatic intrusion beneath the crater floor the emplacement of a shallow magmatic body should result in a positive bouguer anomaly relative to unaltered complex craters a signal which is observed for the average bouguer anomaly interior to the crater walls we observe the bouguer anomaly of floor fractured craters on an individual basis using the unfiltered bouguer gravity solution from grail and also a degree 100 600 band filtered bouguer gravity solution the low magnitude of anomalies arising from shallow magmatic intrusions makes identification using unfiltered bouguer gravity solutions inconclusive the observed anomalies in the degree 100 600 bouguer gravity solution are spatially heterogeneous although there is spatial correlation between volcanic surface morphologies and positive bouguer anomalies we interpret these observations to mean that the spatial heterogeneity observed in the bouguer signal is the result of variable degrees of magmatic degassing within the intrusions

eruption versus intrusion arrest of propagation of constant volume buoyant liquid filled cracks in an elastic brittle host received 9 january 2009 revised 31 march 2009 accepted 3 april 2009 published 5 june 2009 1 when a volume of magma is released from a source at depth one key question is whether or not this will culminate in an eruption or in the emplacement of a shallow intrusion we address some of the physics behind this question by describing and interpreting laboratory experiments on the propagation of cracks filled with fixed volumes of buoyant liquid in a brittle elastic host experiments were isothermal and the liquid was incompressible the cracks propagated vertically because of liquid buoyancy but were then found to come to a halt at a configuration of static mechanical equilibrium a result that is inconsistent with the prediction of the theory of linear elastic fracture mechanics in two dimensions we interpret this result as due to a three dimensional effect at the curved crack front horizontal cracking is necessary in order for vertical propagation to take place as the crack elongates and thins the former becomes progressively harder and in the end impossible to fracture we present a scaling law for the final length and breadth of cracks as a function of a governing dimensionless parameter constructed from the liquid volume the buoyancy and host fracture toughness an important implication of this result is that a minimum volume of magma is required for a volcanic eruption to occur for a given depth of magma reservoir

regolith structure analysis a contribution to understanding the local occurrence of shallow landslides austrian tyrol abstract this study focuses on shallow landslides on alpine slopes usually triggered by extreme rainfall events or rapid snowmelt shallow landslides cause soil loss of agricultural land and can even induce larger mass movements to estimate shallow landslide susceptibility it is crucial to understand the interactions of the conditioning factors the structure of the shallow subsurface regolith represents the least well known variable hydrological characteristics of the slope and its resulting stability depend very much on the structure and thickness of the regolith however conditions of the shallow subsurface have hitherto not been investigated in detail due to difficulties in area wide data collection by adapting a common method from engineering sciences our research provides new insights into the small scale structure of a regolith body on an alpine slope in the inner schmirn valley tyrol austria we carried out field measurements by applying densely spaced lightweight dynamic cone penetrometer tests dcpt on a test site of 30 m by 30 m to cope with the three dimensional 3d characteristics of the regolith body we suggest the application of a 3d volumetric lattice voxel model for the analysis of patterns and variations in the penetration resistance we propose a spatial interpolation by the regularized spline with tension rst method we approximated three different geotechnical parameters i the thickness of the local regolith ii the penetration resistance within the regolith and iii the surface of the solid bedrock an exploratory analysis allowed us to describe surface and bedrock morphology and to detect discontinuities in the regolith in the immediate vicinity of the landslide in addition we were able to establish a distinct spatial relation of the derived geotechnical parameters and slope failure the proposed method was developed tested and verified in an individual case study but the results indicate a great potential for future applications in shallow landslide susceptibility analysis the findings of this study improve knowledge on the relation between shallow subsurface structure and the occurrence of shallow landslides they also allow predictions about the potential evolvement of existing shallow landslides through secondary gliding processes

a concise compilation of petrologic information on possibly pristine nonmare moon rocks ansrn q cr to facilitate systematic study of the surviving compositionally pristine endogenously igneous rocks of the ancient lunar crust a compilation has been generated of all likely samples along with key information on the petrologic characteristics and chemistry of each sample the compilation includes 260 samples besides information related to the likelihood of each sample being truly pristine i e mainly its texture and siderophile element abundances information is compiled on mineral content listing major phases present as well as basic information on mineral compositions on size expressed as mass and on whether a reasonably comprehensive chemical analysis has been published the compilation also classifies the samples into seven categories of confidence in the pristine composition of the samples reflecting an estimation of the relative likelihood that each arguably pristine sample is in fact pristine for many purposes it is crucial to avoid inclusion of polymict rocks in a data base on petrologic diagrams such as a plot of average mg mg 100 x molar mg mg fe in a low ca mafic silicate vs average an content in plagioclase rocks in the top three categories of the confidence in pristine character appear distinctly bimodal in composition with roughly half belonging to a ferroan suite characterized by high an despite relatively low mg when samples of low to moderate pristine character are included the bimodality appears less distinct sample mass can also be important with a data base restricted to samples more massive than i g there is a clear distinction in feldspar content and bulk density between ferroan and nonferroan mgsuite rocks such that only the ferroan suite rocks are likely to have formed as flotation cumulates with a data base including smaller samples the same basic pattern is seen but only in a blurred form as the two rock types show considerable overlap in their modal feldspar contents

regionalization of rainfall thresholds an aid to landslide hazard evaluation rainfall soil properties and morphology are major factors controlling shallow landsliding a series of meteorological events that triggered soil slips in northern italy were studied to define rainfall thresholds and to evaluate a possible regionalization soil properties triggering rainfall and local lithological and morphometrical settings of different sites were used as input to an infiltration model the approach allows the recognition of several triggering conditions in the piedmont pre alpine and alpine regions this suggests the need for different rainfall thresholds with respect to those derived with other methods intensity versus rainfall duration relationships become particularly important when related to soil permeability and thickness and demonstrate the role of antecedent precipitation events with exceptional water discharge from obstructed road culverts reveal the role played by anthropic structures in triggering such phenomena different approaches to slope stability analysis are shown taking into account bedrock lithology topography seepage and local saturation conditions

on the potential for lunar highlands mg suite extrusive volcanism and implications concerning crustal evolution abstract the lunar magnesian suite mg suite was produced during the earliest periods of magmatic activity on the moon based on the cumulate textures of the samples and a lack of evidence for mg suite extrusives in both the sample and remote sensing databases several petrogenetic models deduce a predominantly intrusive magmatic history for mg suite lithologies considering that 18 of the lunar surface is covered by mare basalt flows which are substantially higher in density than estimated mg suite magmas 2900 versus 2700 kg m3 the apparent absence of low density mg suite volcanics is surprising were mg suite magmas predominantly intrusive or have their extrusive equivalents been covered by subsequent impact ejecta and or later stage volcanism if mg suite magmas were predominantly intrusive what prevented these melts from erupting or if they are present as extrusives what regions of the moon are most likely to contain mg suite volcanic deposits this study investigates buoyancy driven ascent of mg suite parental melts and is motivated by recent measurements of crustal density from grail mg suite dunite troctolite and spinel anorthosite parental melts 2742 2699 and 2648 kg m3 respectively are considered all of which have much lower melt densities relative to mare basalts and picritic glasses mg suite parental melts are more dense than most of the crust and would not be expected to buoyantly erupt however about 10 of the lunar crust is greater in density than mg suite melts these areas are primarily within the nearside southern highlands and south pole aitken sp a basin mg suite extrusions and or shallow intrusions were possible within these regions assuming crustal density structure at 4 1 ga was similar to the present day crust we review evidence for mg suite activity within both the southern highlands and sp a and discuss the implications concerning crustal evolution as well as mg suite petrogenesis lower crustal densities measured by grail are consistent with the lack of observed mg suite extrusives if mg suite extrusive volcanism was prevented by the low density of the crust it would suggest the lunar crust was fractured shortly after solidification 4 3 ga the thermal and stress state of the lunar crust may have also inhibited mg suite extrusion

dynamics of magmatic intrusions in the upper crust theory and applications to laccoliths on earth and the moon 1 to understand the dynamics of shallow magmatic intrusions i propose a theoretical model of magma spreading laterally below an elastic crust nondimensionalization of the flow equation leads to the identification of characteristic scales for the intrusion while the characteristic intrusion length is controlled by the elastic response of the crust its characteristic thickness primarily depends on magma properties and injection rate three spreading regimes are identified and characterized by different morphologies as well as by scaling laws for thickness versus length and thickness versus time the first spreading regime is controlled by the elastic response of the crust and the shape of the flow is self similar when the time length and thickness become larger than an elastic time length and thickness scale the edges of the flow become steeper and the system transitions to a gravity current regime when the intrusion is thick enough to accommodate the pressure head the flow enters a regime of lateral propagation and keeps a constant thickness the intrusion shape in the elastic regime fits the observed shape of terrestrial laccoliths the elastic scaling law for intrusion thickness versus length fits observations of laccoliths at elba island italy and provides for a physical explanation for the observed relationship between length and thickness on terrestrial laccoliths laccoliths are predicted to form over short time scales depending on magma viscosity that vary between approximately a month to several years for felsic magmas on earth on the moon several elongated low slope domes have recently been identified as possibly formed by laccolith intrusions at depth although they are much larger than terrestrial laccoliths because the moon has a smaller gravity than on the earth a deeper magma source and a more mafic magma composition than for terrestrial laccoliths implying smaller pressure gradient and dike width lunar intrusions have a larger characteristic length and a smaller characteristic thickness after nondimensionalization the morphologies length versus thickness of terrestrial and inferred lunar laccoliths follow the same curve and are well fitted by the elastic scaling law this model thus explains the size discrepancy between terrestrial laccoliths and lunar low slope domes therefore low slope domes identified on the moon are good candidates for laccolith type intrusions at depth

failure characteristics of rainfall induced shallow landslides in granitic terrains of shikoku island of japan soil slips debris slides and flow occurrences on hill slopes of particular areas are closely related to the mode of rainfall because of geological geomorphological and climatic settings japan is highly prone to rainfall induced landslides in 2004 shikoku the smallest island of japan faced extreme events of typhoon rainfalls and suffered huge losses of life and property because of floods and landslides this paper deals with the synoptic descriptions of failures that occurred in the granitic terrain of northeast shikoku island japan along with rainfall and failure relationships during the typhoon 0423 tokage of 2004 examples of typical failures that occurred in moriyuki and monnyu of northeast shikoku are taken into consideration in this study data from laboratory and field were used to perform sensitivity and stability analyses with respect to varying slope angles strength parameters and thicknesses of saturated residual soil this study attempts to employ a standard method of stability analysis of translational slides which are very common in masa soil weathered granite during extreme rainfall average rainfall intensities and duration during typhoon tokage were also used to interpret landslide triggering thresholds for the study area

susceptibility and triggering scenarios at a regional scale for shallow landslides abstract the work aims at identifying susceptible areas and pluviometric triggering scenarios at a regional scale in calabria italy with reference to shallow landsliding events the proposed methodology follows a statistical approach and uses a database linked to a gis that has been created to support the various steps of spatial data management and manipulation the shallow landslide predisposing factors taken into account are derived from i the 40 m digital terrain model of the region an 15 075 km2 extension ii outcropping lithology iii soils and iv land use more precisely a map of the slopes has been drawn from the digital terrain model two kinds of covers prevalently coarse grained cg cover or fine grained fg cover were identified referring to the geotechnical characteristics of geomaterial covers and to the lithology map soilscapes were drawn from soil maps and finally the land use map was employed without any prior processing subsequently the inventory maps of some shallow landsliding events totaling more than 30 000 instabilities of the past and detected by field surveys and photo aerial restitution were employed to calibrate the relative importance of these predisposing factors the use of single factors first level analysis therefore provides three different susceptibility maps second level analysis however enables better location of areas susceptible to shallow landsliding events by crossing the single susceptibility maps on the basis of the susceptibility map obtained by the second level analysis five different classes of susceptibility to shallow landsliding events have been outlined over the regional territory 8 9 of the regional territory shows very high susceptibility 14 3 high susceptibility 15 moderate susceptibility 3 6 low susceptibility and finally about 58 very low susceptibility finally the maps of two significant shallow landsliding events of the past and their related rainfalls have been utilized to identify the relevant pluviometric triggering scenarios by using 205 daily rainfall series different triggering pluviometric scenarios have been identified with reference to cg and fg covers a value of 365 mm of the total rainfall of the event and or 170 mm d of the rainfall maximum intensity and a value of 325 mm of the total rainfall of the event and or 158 mm d of the rainfall maximum intensity are able to trigger shallow landsliding events for cg and fg covers respectively the results obtained from this study can help administrative authorities to plan future development activities and mitigation measures in shallow landslide prone areas in addition the proposed methodology can be useful in managing emergency situations at a regional scale for shallow landsliding events triggered by intense rainfalls through this approach the susceptibility and the pluviometric triggering scenario maps will be improved by means of finer calibration of the involved factors

chemical variation of the large apollo 15 olivine normative mare basalt rock samples most chemical analyses of apollo 15 olivine normative mare basalts have been conducted on subsamples of 4 g to obtain greater whole rock representivity these subsamples were individually ground and homogenized and splits were taken for analysis furthermore we used both x ray fluorescence and neutron activation techniques to analyze for a comprehensive set of elements suitable for petrogenetic interpretation the analyses show that the samples form a single coherent suite with almost all of the variation corresponding with olivine control 15 range a few of the coarser rocks are not quite represented even at this sampling size the analyses show that the rocks are individually distinct and that analyses are not merely of unrepresentative pieces of a single rock undifferentiated rock unit or rocks differing only by short range unmixing of residual fluids the petrographic features including the low abundance of olivine and its small size and the vesicularity of even some of the coarser samples show that the olivine that controlled the chemical variation is not accumulated in any of the rocks the apollo 15 olivine normative mare basalts were extruded as a series of magmas from a shallow but not locally surficial olivine accumulating magma system and formed a sequence of thin flows a greater understanding of the relationships within and among other mare basalt sequences would be obtained by obtaining comprehensive chemical analyses on splits taken from subsamples of 5 g of all rocks large enough to obtain such subsamples

magmatic intrusions and deglaciation at mid latitude in the northern plains of mars abstract on earth igneous rocks are generally affected by magmatic differentiation and the volume of intrusive bodies is considered to be 5 10 times larger than the volume of volcanic rocks in contrast in the case of mars the occurrence of olivine phyric basalts at gusev crater mcsween h y 2006 j geophys res planets 111 e10 e02s10 the primitive nature of at least four picritic shergottites grott m 2013 planet space sci 174 49 111 and the chemical composition of major volcanic provinces baratoux d toplis m j monnereau m gasnault o 2011 nature 472 338 341 suggest that primary melts of the mantle may have commonly reached the surface these observations together with sparse morphologic evidence of intrusions in comparison with other terrestrial planets raise the issue of the conditions for the formation and occurrence of sub surface zones of magma storage on mars in this respect a series of two types of young amazonian domes located at mid latitudes in western arcadia planitia east of phlegra montes previously interpreted as surface expressions of intrusive bodies farrand w h lane m d edwards b r yingst r a 2011 icarus 211 139 156 are examined here a fraction of the domes consist of upraised plain material whereas others distinguished by a massive core and a large aspect ratio could be partially exhumed intrusions or extrusions of viscous differentiated magma the latter interpretation is however not compatible with the mafic compositions inferred from orbital visible and near infrared spectroscopic observations the thicknesses and radii of both types of domes appear to be related through a power law relationship with exponents close to 1 or 5 4 these exponent values are not compatible with extrusive morphologies but are characteristic of intrusions magma below an elastic layer michaut c 2011 j geophys res 10 1029 2010jb008108 we conclude that all types of domes are intrusive bodies the large aspect ratios of some of these features may be reconciled with a mafic composition and a shallow emplacement a few hundred meters as well as a relatively large injection rate magma emplacement below an ice rich horizon that was subsequently removed offers a plausible scenario for their partial exhumation this scenario is supported by independent signs of ice removal and deflation events in the northern plains the formation of these intrusions appear therefore to be related to an unusual context of magma ascent below a thick and low density ice rich horizon

floor fractured impact craters on venus implications for igneous crater modification and local magmatism regional tectonism and volcanism affect crater modification and crater loss on venus but a comparison of venusian craters to lunar floor fractured craters suggests that a third style of more localized crater controlled magmatism also may occur on venus based on lunar models for such magmatism venusian crustal conditions should generally favor crater filling volcanism over crater centered floor fracturing nevertheless three craters on venus strongly resemble extensively modified craters on the moon where deformation can be attributed to failure over large crater centered intrusions models for crater modification over igneous intrusions indicate typical magmatic pressures beneath these three craters of 200 300 bars and intrusion depths of the order of 1 6 km all three craters also share common settings and low elevations whereas craters embayed by regional volcanism preferentially occur at much higher elevations on venus we suggest that the style of igneous crater modification on venus thus may be elevation dependent with crater centered intrusions primarily occurring at low elevations on venus this interpretation is consistent with theoretically predicted variations in magmatic neutral buoyancy depth as a function of atmospheric pressure suggested by other authors

lunar anorthosite 60025 the petrogenesis of lunar anorthosites and the composition of the moon systematic variations of the mineral chemistry of ferroan anorthosite 60025 which is probably a mixture of closely related materials suggest that lunar anorthosites formed by strong fractional crystallization and near perfect adcumulate growth without trapping liquid the parent liquid for the most primitive samples was saturated with olivine plagioclase pigeonite and chromite and evolved to one saturated with plagioclase pigeonite high ca pyroxene and ilmenite the parent liquid also had a very low na2o content and combined with strong fractional crystallization this explains the steep trend of anorthosites on an mg atomic 100 mg mg fe v an diagram the mineral and chemical data for other anorthosites are consistent with such a model near perfect adcumulation can occur if growth takes place at the crystal liquid interface without the physical accumulation of crystals grown elsewhere and is encouraged by the shifts in phase boundaries with pressure anorthosites are probably the remnants of a crust floating on and crystallizing at the surface of a magma ocean originally of bulk moon composition mineralogical and trace element data suggest that the parental liquid for the most primitive anorthosites had previously crystallized no plagioclase and some but perhaps very little pyroxene hence the bulk moon appears to be similar to that proposed by ringwood 1976 but to have even lower alkalis a subchondritic caal ratio and ree abundances and patterns close to chondritic the mare basalt sources are not directly complementary to the feldspathic crust because experimental and trace element data indicate that they are too magnesian and contain too much high ca pyroxene other crustal rocks such as the mg suite samples are not closely related to anorthosites in addition to their chemical differences they have a different crystallization sequence ol plag px in contrast with the ol px plag inferred for anorthosite parental liquid evolution

lunar floor fractured craters classification distribution origin and implications for magmatism and shallow crustal structure 1 floor fractured craters ffcs are a class of lunar craters characterized by anomalously shallow floors cut by radial concentric and or polygonal fractures additional interior features are moats ridges and patches of mare material two formation mechanisms have been hypothesized floor uplift in response to shallow magmatic intrusion and sill formation and floor shallowing in response to thermally driven viscous relaxation this study combines new lunar orbiter laser altimeter lola and lunar reconnaissance orbiter camera lroc data to characterize and categorize the population of ffcs and map their distribution on the moon and uses variations in floor fractured crater morphology and regional distribution to investigate the proposed formation mechanisms the population of ffcs was categorized according to the classes outlined by schultz 1976 the distribution of these ffc categories shows an evolution of crater morphology from areas adjacent to lunar impact basins to areas in the lunar highlands we propose that this trend is supportive of formation by shallow magmatic intrusion and sill formation crustal thickness determines the magnitude of magmatic driving pressure and thus either piston like floor uplift for high magnitude or a convex floor profile for low magnitude predictions from previous studies modeling viscous relaxation are inconsistent with the observed altimetric profiles of ffcs hence our analysis favors ffc formation by shallow magmatic intrusion with the variety of ffc morphologies being intimately linked with location and crustal thickness and the driving pressure of the intrusion data from the grail gravity recovery and interior laboratory mission will help to test these conclusions

application of an integrated geotechnical and topographic monitoring system in the lorano marble quarry apuan alps italy abstract accurate slope stability analysis is essential for human activity in high risk geological contexts this may however not be enough in the case of quarrying where the dynamic and evolving environment also requires effective monitoring a well designed monitoring system requires the acquisition of a huge dataset over time improving knowledge of the study area and helping to refine prediction from stability analysis this paper reports the implementation of an integrated monitoring system in a marble quarry in the apuan alps italy and some of the results obtained the equipment consists of a traditional geotechnical monitoring system extensometers crackmeters and clinometers and two modern topographic monitoring systems a terrestrial interferometer and a robotic total station this work aims to provide in depth knowledge of the large scale rock mass behaviour as a result of marble exploitation thereby allowing continuous excavation the results highlight the importance of integrating different monitoring systems

investigation of target property effects on crater populations in long lava flows a study in the cerberus region mars with implications for magma source identification abstract young volcanism on mars is exemplified within the cerberus region which enables examination of relatively pristine lava flow surfaces in this investigation we derived model ages within the circum cerberus channelized lavas for sites proximal medial and distal to the lava flow sources finding that these ages decrease with increasing distance from the inferred source investigating multiple possible explanations for this downstream decrease in model ages we conclude that the most likely cause is changes in the rheological properties of the lava during emplacement analogous terrestrial lava flows exhibit rheological changes along their length during emplacement supporting the hypothesis that target properties affect crater size frequency distributions csfds on extraterrestrial bodies using scaling methods we investigated how possible material property changes in the cerberus channelized lavas affected csfds to derive a single model age for each channel we arithmetically size scaled the distal and proximal crater sizes we also used pi group scaling to estimate the effect of material strength and porosity on the final csfds we infer that the athabasca grjota and marte valles lavas underwent minor moderate and major rheological changes respectively to account for the progressively larger age discrepancies along their respective flow lengths the arithmetic size scaling yields relative lava emplacement ages from oldest to youngest respectively as grjota marte and athabasca this lack of a consistent progressive directional emplacement east to west or west to east of lava model ages implies that the magma source was spatially distributed beneath the cerberus region although magma contributions from the two bordering volcanic provinces cannot be ruled out the results of this study support the findings of previous lunar and martian studies that inferred target property changes affected csfds which may have some bearing on age dating of young lava surfaces across the inner solar system

sedimentary cycles and paleogeography of the dnieper donets basin during the late visean serpukhovian based on multiscale analysis of well logs abstract an integrated approach combining the available geological geophysical information was employed to construct a series of paleogeographic maps of the northwestern part of the dnieper donets basin ddb during the late visean serpukhovian early carboniferous the major source of information consists of well log data the basin fill shows a pattern of stacked transgressive regressive units of different order correlations on the scale of the basin are based on biostratigraphy seismics cyclostratigraphic subdivisions and correlations of the successions throughout the basin the cyclicity has a multifold character short shallowing upward transgressive regressive t r cycles characterized by the presence of hydrocarbons productive horizons cover a time span of the order of 500 ka long cycles include 4 to 6 short t r cycles they seem to be correlatable to western europe and probably to north america the long cycles form part of higher order stacking patterns indicative of still longer cycles considering the variable thickness of the cycles throughout the basin tectonics must have influenced the character of the series in addition to glacio eustatic sea level fluctuations the paleogeographical development of the basin shows axial deposition during the late visean likely related to late stage rifting related subsidence of a central graben followed by basin wide subsidence related to thermal subsidence during the serpukhovian

ancient selenophysical structure of the grimaldi basin constraints from grail gravity and lola topography abstract the grimaldi impact basin is located near the western limb of the moon and lies to the southwest of the oceanus procellarum a clearly visible positive gravity anomaly exists in its low lying inner wall implying a subsurface mass concentration beneath the crater exploration of this basin could extend our meaningful and fundamental understanding of giant impact processes as well as the structure of mare basins craters limited by the low resolution of previous gravity field models it was once impossible to explore the structure beneath grimaldi the recent high resolution gravity data from the gravity recovery and interior laboratory mission make it possible to break through this barrier prior to our investigation of the selenophysical structure around crater grimaldi we developed a flexure model that includes surface and subsurface loads a localized admittance analysis was performed by combining high resolution gravity data with the high resolution topography data obtained from lunar orbiter laser altimeter within 2 std error constraints we estimated the best fit parameters over grimaldi as well as two other places in its neighborhood all the predicted admittances show a goodness of fit with their corresponding observations the large load ratio 9 2 found at the grimaldi is an indirect mirror of the dominant subsurface load consistent with its large positive gravity anomaly in its low lying floor not only the crustal thickness of 48 km but also the crustal density of 2500 kg m 3 found around grimaldi shows a great accordance with the recent results of grail given the best fit parameters of f bc and c the elastic thickness te is found to be around 28 km over grimaldi taking into account the best fit values in its neighborhood a regional elastic thickness of 30 km could be roughly concluded around grimaldi which is completely in the previous ranges 20

global imaging of polar cap patches with dual airglow imagers during a 2 h interval from 2240 to 2440 ut on 12 november 2012 regions of increased 630 0 nm airglow emissions were simultaneously detected by dual all sky imagers in the polar cap one at longyearbyen norway 78 1 n 15 5 e and the other at resolute bay canada 74 7 n 265 1 e the resolute bay incoherent scatter radar observed clear enhancements of the f region electron density up to 1012 m 3 within these airglow structures which indicates that these are optical manifestations of polar cap patches propagating across the polar cap during this interval of simultaneous airglow imaging the nightside dawnside dayside duskside half of the patches was captured by the imager at longyearbyen resolute bay this unique situation enabled us to estimate the dawn dusk extent of the patches to be around 1500 km which was at least 60 70 of the width of the antisunward plasma stream seen in the super dual auroral radar network convection maps in contrast to the large extent in the dawn dusk direction the noon midnight thickness of each patch was less than 500 km these observations demonstrate that there exists a class of patches showing cigar shaped structures such patches could be produced in a wide range of local time on the dayside nearly simultaneously and spread across many hours of local time soon after their generation

probabilistic rainfall thresholds for triggering debris flows in a human modified landscape abstract in the carrara marble basin cmb apuan alps italy quarrying has accumulated widespread and thick quarry waste lying on steep slopes and invading valley bottoms the apuan alps are one of the rainiest areas in italy and rainstorms often cause landslides and debris flows the stability conditions of quarry waste are difficult to assess owing to its textural geotechnical and hydrogeological variability therefore empirical rainfall thresholds may be effective in forecasting the possible occurrence of debris flows in the cmb three types of thresholds were defined for three rain gauges of the cmb and for the whole area rainfall intensity rainfall duration id cumulated event rainfall rainfall duration ed and cumulated event rainfall normalized by the mean annual precipitation rainfall intensity emapi the rainfall events recorded from 1950 to 2005 was analyzed and compared with the occurrence of debris flows involving the quarry waste they were classified in events that triggered one or more debris flows and events that did not trigger debris flows this dataset was fitted using the logistic regression method that allows us to define a set of thresholds corresponding to different probabilities of failure from 10 to 90 and therefore to different warning levels the performance of the logistic regression in defining probabilistic thresholds was evaluated by means of contingency tables skill scores and receiver operating characteristic roc analysis these analyses indicate that the predictive capability of the three types of threshold is acceptable for each rain gauge and for the whole cmb the best compromise between the number of correct debris flow predictions and the number of wrong predictions is obtained for the 40 probability thresholds the results obtained can be tested in an experimental debris flows forecasting system based on rainfall thresholds and could have implications for the debris flow hazard and risk assessment in the cmb

two models for the formation of magma reservoirs by small increments abstract it is now clear that magma reservoirs develop over long time intervals out of a large number of individual intrusions evidence from some large volcanic deposits including those of the bishop tuff california and fish canyon tuff colorado indicates that such reservoirs may experience pervasive and rapid heating before catastrophic eruptions injection of hot primitive melt in the reservoir is often invoked to explain these observations but this requires the rapid emplacement of a large magma volume at least 25 km 3 in less than 100 years for the bishop tuff and efficient heat transfer through a thick cumulate pile within a magma body that grows incrementally temperatures rise progressively and may eventually lead to a permanent volume of melt temperature and crystallization follow two completely different paths depending on the thickness of individual intrusive sheets in one limit corresponding to thick sheets crystallization proceeds at equilibrium initial magma batches crystallize completely and a permanent body of melt develops progressively once ambient temperatures in the complex rise above the solidus in the other limit corresponding to thin sheets crystallization is kinetically controlled such that initial intrusions do not crystallize completely and preserve a glassy residue once temperatures within the growing magma pile reach a certain threshold value nucleation and growth of crystals get reactivated in the residual glass crystallization then proceeds catastrophically in a positive feedback loop involving latent heat release and temperature rise thus an initial phase with no evolved melt present ends with the sudden formation of a large volume of evolved melt in a crystal mush after this initial phase new intrusions get emplaced in heated surroundings and follow a thermal path similar to that of the equilibrium case with melts that become increasingly more primitive with time evidence for kinetic controls on crystallization in the natural environment is provided by the significant amounts of glass up to 40 that are found in thin isolated basaltic sills and dykes owing to sluggish crystallization kinetics more glass should be generated in andesitic and dacitic magmas emplaced in similar conditions devitrification of such quantities of glass accounts for the rapid heating of a thick sill complex the two models of magma reservoir formation involve different requirements the intrusion thickness must be smaller than a critical value in the kinetic model and the average magma input rate must exceed a threshold value in the equilibrium model for a given injection rate a permanent magma reservoir forms in a shorter time interval and over a smaller cumulative magma thickness in the kinetic model than in the equilibrium one the kinetic model is such that the amount of evolved melt generated increases with decreasing injection rate in contrast to the equilibrium model for which the opposite relationship holds

multidisciplinary investigations in evaluating landslide susceptibility an example in the serchio river valley italy abstract the proposed experimental study is aimed at contributing to the landslide susceptibility evaluation using a multidisciplinary approach geological geomorphological and geo engineering survey together with multivariate statistical analysis and gis technique it is included in a wider research project aimed at defining the landslide hazard in the area of the map no 250 castelnuovo di garfagnana 1 50 000 scale this study is based on the realization of a landslides inventory map and statistical data analysis using probabilistic methods the methodology applied in ranking slope instability proceeded step by step at first geomorphologic investigation was performed in order to realize a landslide inventory map a gis database was created to collect the characteristics related to landslides geometry type of movement and state of activity geo engineering survey and characterization with in situ and laboratory tests allowed assessing rock mass classification and geotechnical properties of soils texture and consistency the statistical approach for evaluating the landslide susceptibility is based on the assumption that the landslide probability for the currently landslides free areas could be evaluated studying the conditions which led to past and present instability a set of environmental factors thought to be related to landslides were analysed and their spatial distribution organized in different layers then gis supported spatial analysis conditional and multivariate analysis allowed to calculate the connections between instability factors and landslide distribution this step evolved towards two distinct statistical methods both indirect and quantitative leading to a classification of the land surface in some different susceptibility domains conditional analysis was applied to a particular type of terrain unit named unique condition unit ucu that is a unique combination of the instability factors the computer aided evaluation of the landslide index within each ucu represents the probability of landslide occurrence according to bayes statistical concept multivariate analysis was applied to the same set of instability factors but to a different type of terrain unit the grid cell the results showed a quantitative response more reliable about the effectiveness of each instability factors with the possibility of verifying their statistical significance

density porosity and magnetic susceptibility of achondritic meteorites as part of a large scale survey of meteorite bulk and grain densities porosities and magnetic susceptibilities we measured these properties for 174 stones from 106 achondritic meteorites these include four lunar meteorites 15 stones from 10 shergottites nakhlites and chassignites sncs 96 stones from 56 howardites eucrites and diogenites heds 17 stones from nine aubrites two angrites and 16 stones from 10 ureilites four stones of three acapulcoites as well as four stones of three lodranites and 15 stones from eight primitive achondrites those meteorites derived from basalts and crustal material of differentiated parent bodies have lower densities and magnetic susceptibilities on an average than the more primitive achondrites which have a higher percentage metal a notable exception is the one chassignite in the study chassigny which has a high grain density of 3 73 0 04 g cm 3 ureilites have magnetic susceptibilities consistent with primitive achondrites but lower grain densities porosities do not vary considerably between most of the groups with most stones 5 14 porous although on an average ureilites and brachinites have lower porosities with most stones less than 7 porous for primitive achondrites the higher metal content causes finds to exhibit weathering effects similar to what is observed in ordinary chondrites with a reduction in grain density magnetic susceptibility and porosity as compared with unweathered falls for lunites sncs and heds no such effect is observed we also observe that grain density and magnetic susceptibility used in conjunction distinguish shergottites nakhlites and chassignites from each other shergottites and nakhlites have low grain densities averaging 3 31 and 3 41 g cm 3 respectively whereas chassigny is 3 7 g cm 3 in magnetic susceptibility shergottities and chassignites are similar averaging 2 85 and 2 98 in log units of 10 9 m3 kg 1 respectively with nakhlites averaging higher at 3 42

porosities of lunar meteorites strength porosity and petrologic screening during the meteorite delivery process porosity has been directly measured for eight lunar meteorite breccias and calculated for two more on the basis of literature density measurements lunar meteorite regolith breccias display systematically low porosity in comparison to otherwise analogous apollo regolith breccias among seven meteoritic regolith breccias porosity ranges from 1 to 11 and averages 7 5 1 3 2 whereas for 44 analogous apollo samples porosities mostly calculated from literature density data the average is 25 1 7 the origin of this disparity is enigmatic but the trend probably reflects mainly a bias in favor of strong compact breccias among fragments that manage to survive the violent process of launch to lunar escape velocity 2 38 km s in addition compaction during launch may play an important role the population of lunar meteorites is clearly not a random unmodified sample of lithic materials near the surface of the parent body