scaling and parametrization of clear sky solar radiation over complex topography 1 solar radiation at the land surface is influenced by slope aspect shadows and obstruction of the sky all of which vary over a wide range of length scales in regions of complex topography with important consequences for the surface energy balance atmospheric models however generally assume the surface to be flat on subgrid scales for four areas in north america ranging in latitude from 39 n to 69 n and in topography from rolling to mountainous we simulate spatial patterns of clear sky incoming solar radiation it is found that distributions of slope components and variations in shaded area with solar elevation can be approximated by simple functions that scale to each of the areas studied from these results parametrizations are developed for averages standard deviations and distributions of direct beam and diffuse solar radiation results from these parametrizations and from a modified form of a simpler parametrization presented previously compare well with statistics from the spatial simulations the only topographic input required by the parametrizations is the standard deviation of slope components this parameter is again found to have simple scaling relationships with the resolution and extent of the underlying elevation grid and with the standard deviation of elevation

summary of the results from the lunar orbiter laser altimeter after seven years in lunar orbit in june 2009 the lunar reconnaissance orbiter lro spacecraft was launched to the moon the payload consists of 7 science instruments selected to characterize sites for future robotic and human missions among them the lunar orbiter laser altimeter lola was designed to obtain altimetry surface roughness and reflectance measurements the primary phase of lunar exploration lasted one year following a 3 month commissioning phase on completion of its exploration objectives the lro mission transitioned to a science mission after 7 years in lunar orbit the lola instrument continues to map the lunar surface the lola dataset is one of the foundational datasets acquired by the various lro instruments lola provided a high accuracy global geodetic reference frame to which past present and future lunar observations can be referenced it also obtained high resolution and accurate global topography that were used to determine regions in permanent shadow at the lunar poles lola further contributed to the study of polar volatiles through its unique measurement of surface brightness at zero phase which revealed anomalies in several polar craters that may indicate the presence of water ice in this paper we describe the many lola accomplishments to date and its contribution to lunar and planetary science

anticipated electrical environment within permanently shadowed lunar craters 1 shadowed locations near the lunar poles are almost certainly electrically complex regions at these locations near the terminator the local solar wind flows nearly tangential to the surface and interacts with large scale topographic features such as mountains and deep large craters in this work we study the solar wind orographic effects from topographic obstructions along a rough lunar surface on the leeward side of large obstructions plasma voids are formed in the solar wind because of the absorption of plasma on the upstream surface of these obstacles solar wind plasma expands into such voids producing an ambipolar potential that diverts ion flow into the void region a surface potential is established on these leeward surfaces in order to balance the currents from the expansion limited electron and ion populations we find that there are regions near the leeward wall of the craters and leeward mountain faces where solar wind ions cannot access the surface leaving an electron rich plasma previously identified as an electron cloud in this case some new current is required to complete the closure for current balance at the surface and we propose herein that lofted negatively charged dust is one possible nonunique compensating current source given models for both ambipolar and surface plasma processes we consider the electrical environment around the large topographic features of the south pole including shoemaker crater and the highly varied terrain near nobile crater as derived from goldstone radar data we also apply our model to moving and stationary objects of differing compositions located on the surface and consider the impact of the deflected ion flow on possible hydrogen resources within the craters

application of the crosta technique for porphyry copper alteration mapping using etm data in the southern part of the iranian volcanic sedimentary belt abstract many of the known porphyry copper deposits in iran are situated in the central iranian volcanic belt the area under study is located in the southern part of this belt and covers an area of about 6600 km2 the climate in the area is semi arid given the poor soil development and poor vegetation cover but abundant outcrops the arid semi arid part of the belt is most suitable for remote sensing study enhanced thematic mapper plus etm images have been used for alteration mapping crosta method was found useful for enhancing the areas in which the regolith contains a high proportion of hydroxyl and iron oxide minerals the crosta method has been used on selected 4 and 6 bands areas with iron oxide and hydroxyl minerals have been enhanced by using six bands of etm data

climatic records over the past 30 ka from temperate australia a synthesis from the oz intimate workgroup temperate australia sits between the heat engine of the tropics and the cold southern ocean encompassing a range of rainfall regimes and falling under the influence of different climatic drivers despite this heterogeneity broad scale trends in climatic and environmental change are evident over the past 30 ka during the early glacial period 30 22 ka and the last glacial maximum 22 18 ka climate was relatively cool across the entire temperate zone and there was an expansion of grasslands and increased fluvial activity in regionally important murray darling basin the temperate region at this time appears to be dominated by expanded sea ice in the southern ocean forcing a northerly shift in the position of the oceanic fronts and a concomitant influx of cold water along the southeast including tasmania and southwest australian coasts the deglacial period 18 12 ka was characterised by glacial recession and eventual disappearance resulting from an increase in temperature deduced from terrestrial records while there is some evidence for climatic reversals e g the antarctic cold reversal in high resolution marine sediment cores through this period the high spatial density of holocene terrestrial records reveals an overall expansion of sclerophyll woodland and rainforest taxa across the temperate region after 12 ka presumably in response to increasing temperature while hydrological records reveal spatially heterogeneous hydro climatic trends patterns after 6 ka suggest higher frequency climatic variability that possibly reflects the onset of large scale climate variability caused by the el nino southern oscillation

mercury radar imaging evidence for polar ice the first unambiguous full disk radar mapping of mercury at 3 5 centimeter wavelength with the goldstone 70 meter antenna transmitting and 26 antennas of the very large array receiving has provided evidence for the presence of polar ice the radar experiments conducted on 8 and 23 august 1991 were designed to image the half of mercury not photographed by mariner 10 the orbital geometry allowed viewing beyond the north pole of mercury a highly reflective region was clearly visible on the north pole during both experiments this polar region has areas in which the circular polarization ratio pt was 1 0 to 1 4 values 0 1 are typical for terrestrial planets such high values of have hitherto been observed in radar observations only from icy regions of mars and icy outer planet satellites

spectral characterization of igneous rocks in the 8 to 12 μm region variation in the spectral response of silicates in the thermal infrared tir from 8 to 12 m is the foundation for potentially important applications in the lithologic characterization of terrestrial and extraterrestrial surfaces the purpose of this study is to elucidate the crystallo chemical basis for the variation in spectral behavior in terms which may be useful in remote sensing this has led to the definition of a new parameter scfm which is defined as the ratio sio2 sio2 cao feo mgo in minerals and rocks this parameter reflects the degree of depolymerization of the silica tetrahedra and is therefore highly correlated with the structure of tir reflectance spectra of major silicate minerals in both fine and coarse grained igneous rocks it is also a good numerical descriptor of igneous rock composition thus scfm is proposed as a very useful determinant for spectral identification of igneous rocks the scfm parameter was used to assess the effect of variations in location number and width of bands in discriminating rock composition an unfortunate ambiguity exists in the use of the term band which in spectroscopy indicates a feature in a spectrum and in remote sensing signifies a specific wavelength increment or channel the latter definition is used in this paper spectra of coarse particulate mineral and solid rock samples were acquired in the laboratory a regression analysis of bands varying in width from 0 2 to 1 4 m versus scfm results in coefficients of determination correlation coefficients r2 ranging from 0 88 for two 1 2 m wide bands to 0 97 for seven 0 2 m wide bands deletion of bands in the ozone absorption region 9 4 10 2 m results in a decrease in r2 by only 0 01 stimulation of system noise by addition of 5 random counts to the bands decreases r2 by only 0 03 because spectra structure is modified by weathering alteration and texture of the samples the validity of these results is limited to fresh igneous rocks with this constraint it is concluded that accurate spectral identification of igneous rock composition is not greatly affected by bandwidth or system noise it is the overall spectral envelope rather than the fine structure in the tir which contains most of the information diagnostic of igneous rock composition this permits design of remote sensing systems with broad bands and corresponding higher signal to noise which can be traded off against the important requirement for higher spatial resolution

stability of polar frosts in spherical bowl shaped craters on the moon mercury and mars following svitek martian water frost control of global distribution by small scale processes ph d thesis california institute of technology 1992 analytic solutions are presented for the effective albedo the effective emissivity and the radiative equilibrium temperature in the shadowed portions of a spherical bowl shaped crater the model assumes that the surface is a lambert scatterer with visual albedo and infrared emissivity each independent of wavelength across their respective spectral ranges absorption emission and multiple scattering from the walls of the crater are treated rigorously to all orders for airless bodies whose surfaces are in radiative equilibrium all shadowed portions of any individual crater have the same temperature whose value depends on four quantities the insolation product of the solar constant and the sine of the solar elevation angle the depth diameter ratio of the crater the visual albedo and the infrared emissivity as long as the crater is deep enough to have shadows the lowest temperatures are for the shallowest crater those with the smallest depth diameter ratio the model is applied first to the moon and mercury using a depth diameter ratio of 0 2 which is typical of the lunar highlands according to pike geophys res lett 1 291 294 1974 in impact and explosion cratering roddy et al eds pp 489 509 pergamon new york 1977 for mercury and the moon temperatures in shadows in polar craters are below 102 k so the sublimation rate of water ice calculated according to the model of watson et al j geophys res 66 3033 3015 1961 is less than 1 cm per byr the latitudinal extent of the cold zone on the moon is greater than that on mercury although temperatures at the poles of the two planets are similar the other application is to polar frosts on mars illuminated water frosts in radiative equilibrium grow rougher because the average temperature of a depression is greater than that of flat ground subliming co 2 frosts which are always at the same temperature grow rougher at low solar elevation angles because the heat flux absorbed by a depression is greater than that for a flat surface at high insolation rates high sun near perihelion the average heat flux to a depression is less than for a flat surface the latter evaporates faster which makes the average surface smoother and leads to a high average albedo this behavior helps explain the fact that the south co 2 cap which receives its greatest insolation near perihelion has a higher effective albedo and therefore can survive the summer whereas the north co 2 cap has a lower effective albedo and disappears each year around summer solstice

mercury full disk radar images and the detection and stability of ice at the north pole the first full disk radar images of mercury were obtained on august 8 and 23 1991 these images were constructed using the very large array vla in socorro new mexico to receive and map radar flux at 3 5 cm x band which was continuously transmitted from the 70 m jet propulsion laboratory deep space network antenna at goldstone california approximately 77 of the surface was imaged at resolutions as good as 150 km about half of the hemisphere photographed by mariner 10 was imaged as well as most of the hemisphere which has not previously been photographed at the time of the observations the north pole was visible and the feature with the highest same sense ss circular reflectivity in the images is near the nominal polar position the peak ss reflectivity of this feature was 7 9 and the circular polarization ratio throughout much of the feature is 1 our best estimate of the size of the feature is that its diameter is 350 km we interpret the feature to be indicative of the presence of ices because of the signal strength and polarization characteristics the ices must be very clean and were thus probably deposited in a relatively short time period the most likely place to find these ices is in any permanently shadowed areas in the polar regions which would be very cold in comparison to absolute reflectivities of other icy bodies and regions in the solar system the reflectivity of the north polar feature is slightly depressed this is probably because the ices do not fill an observational resolution cell i e there is incomplete areal coverage or are covered by a layer of dust or soil which absorbs some of the incoming and outgoing radar energy or both a covering layer would also protect any ices from erosion by energetic sources other prominent features on the unphotographed hemisphere correspond to positions where atmospheric sodium enhancements have been measured from earth this may indicate that these locations are large basins similar to the caloris basin where an atmospheric potassium enhancement has been measured which may be the result of increased degassing in the disrupted surface and near surface direct comparison of the radar echoes from our features with those from the caloris basin are hard to make as caloris was not imaged by us in a favorable geometry features on the photographed hemisphere are smaller and mostly associated with craters and crater complexes most notably the kuiper crater and its environs

oxygen isotopes and sea level from the time that detailed oxygen isotope records derived from foraminifera living in the constant temperature environment of the abyssal ocean became available there has been a discrepancy between the ice volume record that these records imply and that derived from the altitude of dated coral terraces around the world here we re examine the data and conclude that the temperature of the abyssal ocean has been an actively varying component of the climate system

the clementine mission to the moon scientific overview in the course of 71 days in lunar orbit from 19 february to 3 may 1994 the clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths these data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side in addition laser ranging measurements provided the first view of the global topographic figure of the moon the topography of many ancient impact basins has been measured and a global map of the thickness of the lunar crust has been derived from the topography and gravity

fluxes of fast and epithermal neutrons from lunar prospector evidence for water ice at the lunar poles maps of epithermal and fast neutron fluxes measured by lunar prospector were used to search for deposits enriched in hydrogen at both lunar poles depressions in epithermal fluxes were observed close to permanently shaded areas at both poles the peak depression at the north pole is 4 6 percent below the average epithermal flux intensity at lower latitudes and that at the south pole is 3 0 percent below the low latitude average no measurable depression in fast neutrons is seen at either pole these data are consistent with deposits of hydrogen in the form of water ice that are covered by as much as 40 centimeters of desiccated regolith within permanently shaded craters near both poles

the migration of volatiles on the surfaces of mercury and the moon radar observations of mercury have provided the startling discovery of the probable existence of substantial deposits of ices in permanently shaded polar regions butler et al 1993 harmon et al 1994 this has renewed the old argument about the existence of such deposits in the polar regions of the moon it is most likely necessary for volatiles to be able to migrate to the polar regions of these bodies in order to build up such deposits this paper presents the results of the extension of a monte carlo simulation of the migration of molecules on the surface of mercury by butler et al 1993 the results of the simulations show that for typical conditions on mercury 5 15 of all h 2 o which is placed randomly on the surface migrates to stable permanently shaded polar regions for the moon the numbers are 20 50 the numbers for the migration of co 2 are 2 for mercury and 13 for the moon these percentages are similar to those previously calculated and support the idea of ice deposits in the polar regions of both mercury and the moon

the clementine bistatic radar experiment during the clementine 1 mission a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle beta for selected lunar areas observations of the lunar south pole yield a same sense polarization enhancement around beta 0 analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole radar observations of periodically solar illuminated lunar surfaces including the north pole yielded no such enhancement a probable explanation for these differences is the presence of low loss volume scatterers such as water ice in the permanently shadowed region at the south pole

geologic mapping using thermal images abstract in the past remote sensing from aircraft and satellite for geologic mapping concentrated on the visible and reflective infrared parts of the spectrum because of the availability of landsat and aircraft multispectral scanners operating in this spectral range with the launch of the heat capacity mapping mission hcmm satellite regional thermal image data also became available we have examined the hcmm data for geologic information over two desert areas in southern california the trona area and the pisgah area three techniques were used for displaying and combining thermal data and visible and near infrared including color additive composites principal components and calculation of thermal inertia images use of the color additive composite image was simplest and allowed for simultaneous display of both thermal and reflectance properties thermal data were found to provide additional geologic information unavailable from landsat data or from aircraft visible and near infrared data alone the addition of these data relating to thermal properties allowed separation of rock types with differing thermal properties but with similar reflectance characteristics

geological mapping of the francistown area in northeastern botswana by surface temperature and spectral emissivity information derived from advanced spaceborne thermal emission and reflection radiometer aster thermal infrared data abstract we identified geological units in the francistown area in northeastern botswana by using advanced spaceborne thermal emission and reflection radiometer aster thermal infrared tir data which contains both surface temperature and spectral emissivity information a scatter plot of aster l1b daytime tir digital values and l2 daytime temperature indicates that in the aster l1b daytime tir data bands 10 11 and 12 contain spectral emissivity and temperature information whereas surface temperature dominates the spectral emissivity information in bands 13 and 14 visual interpretation of the aster tir false color composite fcc images generated by assigning red green and blue to band 14 band 12 band 10 using l1b daytime data allowed us to identify mafic to ultramafic units and quartz rich felsic units mafic to ultramafic units such as gabbro dolerite and dunite appear white in aster l1b daytime tir fcc images due to their high spectral emissivities in the 8 9 m region bands 10 and 12 and high surface temperatures mafic to ultramafic units have higher surface temperatures than other geological units because they absorb more solar radiation due to their lower albedos and they have a lower thermal inertia quartz rich felsic units such as granite and dry river sand appear reddish in the aster l1b daytime tir fcc image because the spectral emissivity of quartz is lower in the 8 9 m region bands 10 and 12 than in the 10 12 m region band 14 mafic to ultramafic and granitic units are important targets for mineral exploration because they are potential geological units to host or accompany mineralization the proposed aster l1b daytime tir fcc images can be prepared very simply and they provide valuable information for geological mapping and mineral exploration

a search for water ice at the lunar poles with clementine images abstract optical and near ir signatures of water ice on the moon s surface were sought in the permanently shadowed regions near its poles significant amounts of multiply scattered radiation partly illuminate primary shadows cast by craters and other features if there is water ice in the permanently shadowed regions of the moon s surface its spectral signature should appear in this multiply scattered light this investigation can be done most effectively with observations obtained by spacecraft because most selenocentric positions occupied by the earth will also be occupied by the sun at some point in time and because the lunar poles are seen only obliquely to a terrestrial observer images obtained by clementine are particularly well suited to this task because the spacecraft s polar orbit allowed images of the poles to be acquired on nearly every orbit resulting in literally thousands of images taken within a few degrees of each pole and because the filters on the ultraviolet visual camera uvvis and the near infrared camera nir occur at major absorption bands or within important continuum features of water ice approximately 5800 images obtained by the uvvis camera and 1800 images obtained by the nir camera were calibrated and combined into coadded mosaics to create multispectral maps of the lunar poles with the highest possible signal to noise unfortunately analysis of our uvvis mosaics indicates that any possible signal from multiply scattered light in primary shadows was overwhelmed by instrumental stray light for the nir camera we were able to determine the normalized reflectance of several regions that were identified by margot et al 1999 science284 1658 1660 as permanent shadows we have identified one permanently shadowed crater with a 1 5 m band spectral signature indicative of between 2 5 and 21 fractional coverage of h2o frost however the same region shows a 2 0 m spectral signature that is inconsistent with the presence of any water

the south pole region of the moon as seen by clementine the clementine mission has provided the first comprehensive set of high resolution images of the south pole region of the moon within 5 of latitude of the pole an area of an estimated 30 000 square kilometers remained in shadow during a full lunar rotation and is a promising target for future exploration for ice deposits the schrodinger basin 320 kilometers in diameter centered at 75 s is one of the two youngest least modified great multiring impact basins on the moon a large maar type volcano localized along a graben within the schrodinger basin probably erupted between 1 and 2 billion years ago

topography of the moon from the clementine lidar range measurements from the lidar instrument carried aboard the clementine spacecraft have been used to produce an accurate global topographic model of the moon this paper discusses the function of the lidar the acquisition processing and filtering of observations to produce a global topographic model and the determination of parameters that define the fundamental shape of the moon our topographic model a 72nd degree and order spherical harmonic expansion of lunar radii is designated goddard lunar topography model 2 gltm 2 this topographic field has an absolute vertical accuracy of approximately 100 m and a spatial resolution of 2 5 the field shows that the moon can be described as a sphere with maximum positive and negative deviations of 8 km both occurring on the farside in the areas of the korolev and south pole aitken s p aitken basins the amplitude spectrum of the topography shows more power at longer wavelengths as compared to previous models owing to more complete sampling of the surface particularly the farside a comparison of elevations derived from the clementine lidar to control point elevations from the apollo laser altimeters indicates that measured relative topographic heights generally agree to within 200 m over the maria while the major axis of the lunar gravity field is aligned in the earth moon direction the major axis of topography is displaced from this line by approximately 10 to the east and intersects the farside 24 north of the equator the magnitude of impact basin topography is greater than the lunar flattening 2 km and equatorial ellipticity 800 m which imposes a significant challenge to interpreting the lunar figure the floors of mare basins are shown to lie close to an equipotential surface while the floors of unflooded large basins except for s p aitken lie above this equipotential the radii of basin floors are thus consistent with a hydrostatic mechanism for the absence of significant farside maria except for s p aitken whose depth and lack of mare require significant internal compositional and or thermal heterogeneity a macroscale surface roughness map shows that roughness at length scales of 10 1 10 2 km correlates with elevation and surface age

radar images of the moon at 6 meter wavelength abstract we present new range doppler images of the moon using 6 mwavelength the radar images were obtained using the jicamarca radio observatory 49 92 mhz radar the observations were performed using circular polarization on transmit and two orthogonal linear polarizations on receive allowing scattering images to be obtained with the polarization matched to the transmitted wave polarized and at a polarization orthogonal to the transmitted wave depolarized due to the long wavelength that penetrates efficiently into the subsurface of the moon the radar images are especially useful for studies of subsurface composition two antenna interferometry on receive was used to remove the doppler north south ambiguity the images have approximately 10 km resolution in range 20 km resolution in doppler allowing many large scale features including maria terrae and impact craters to be identified strong depolarized return is observed from relatively new larger impact craters with large breccia and shallow regolith terrae regions with less lossy surface material also appear brighter in both depolarized and polarized images a large region in the area near the mare orientale impact basin has overall higher than mean radar backscatter in both polarized and depolaried returns indicating higher than average presence of relatively newly formed large breccia in this region mare regions are characterized by lower polarized and depolarized return indicating that there is higher loss of the radio wave in the subsurface reducing the echo we also report unexpected low polarized and depolarized backscatter from an old impact basin in the schiller schickard region as well as from the region poleward from mare imbrium

regional thermal inertia mapping from an experimental satellite a new experimental satellite has provided for the first time thermal data that should be useful in reconnaissance geologic exploration thermal inertia a property of geologic materials can be mapped from these data by applying an algorithm that has been developed using a new thermal model a simple registration procedure was used on a pair of day and night images of the powder river basin wyoming to illustrate the method preliminary assessment of these satellite data suggests that they will be of significant use for resource exploration when used in conjunction with other geologic geophysical and geochemical data

the significance of maar volcanoes for palaeoclimatic studies in china abstract the sediments of maar lakes often provide paleoenvironmental records which are highly suitable for palaeoclimatic studies the main advantages of the records from maar lakes compared with other lacustrine records are as follows first the presence of varves annually laminated layers and tephra layers as well as other materials like terrestrial plant macrofossils charcoals organic carbon organic shells suitable for isotopic dating like ams 14c 210pb 137cs 238u 230th 40ar 39ar provides the possibility of developing several independent chronologies enabling the development of robust high resolution chronologies second maars and maar lakes can provide continuous sedimentary records spanning tens of thousands of years tianyang maar in china is hosted the longest known record spanning at least 400 kyr bp that are ideal for the investigation of climate change on different timescales including orbital millennial centennial and annual decadal third recent studies of biomarkers based on long chain alkenones lcas and glycerol dialkyl glycerol tetraethers gdgts have demonstrated the potential of maar lakes for quantitative paleotemperature reconstruction in this study we review some of the more significant achievements of palaeoclimatic research based on maar lake sediment sequences from china with the focus on chronology multiple timescales and quantitative paleoclimatic reconstruction

topography of the lunar poles from radar interferometry a survey of cold trap locations detailed topographic maps of the lunar poles have been obtained by earth based radar interferometry with the 3 5 centimeter wavelength goldstone solar system radar the interferometer provided maps 300 kilometers by 1000 kilometers of both polar regions at 150 meter spatial resolution and 50 meter height resolution using ray tracing these digital elevation models were used to locate regions that are in permanent shadow from solar illumination and may harbor ice deposits estimates of the total extent of shadowed areas poleward of 87 5 degrees latitude are 1030 and 2550 square kilometers for the north and south poles respectively

an early to middle pleistocene palynological record from the volcanic crater of pejark marsh western plains of victoria southeastern australia abstract a discontinuous 70 m sediment core was extracted from the volcanic crater of pejark marsh to temporally extend the existing quaternary record of vegetation and environments from the western plains of victoria the sequence was fission track dated to the early middle pleistocene transition both the sediments and the aquatic pollen indicate a general lake shallowing and progressive increase in drying and peat deposition events the major dry land pollen taxa are similar to those that dominate the late quaternary records from the area and indicate the alternation of regionally dominant sclerophyll forest during wetter periods and steppe or open woodlands during drier periods a major feature of the pollen record is the presence of a number of regionally extinct taxa in the basal half of the record some of these taxa including araucaria canthium and microcachrys represent major range extensions of previously considered regionally extinct taxa into the pleistocene tentative correlation with the marine oxygen isotope record suggests that the sequence may extend from isotope stages 30 to 17 with major changes within the record relating to the transition from the higher frequency lower amplitude orbitally forced climatic cycles of the early pleistocene to the lower frequency higher amplitude cycles of the middle late pleistocene

a late pleistocene and holocene pollen record from lake terang western plains of victoria australia abstract analyses of pollen and charcoal from lake and swamp deposits accumulated in a maar crater are used to reconstruct palaeoenvironments at and around terang western victoria changes in the nature of the sediments and in aquatic and dryland pollen indicate substantial climatic variation within the recorded period pollen assemblages indicate changes from open woodland herbfield and grassland to wet sclerophyll forest and from ephemeral swamp to permanent lake and swamp conditions within the basin a possible timescale for the lake terang sequence is inferred from comparison with the better dated nearby lake wangoom sequence and with the deep sea core record the terang record is considered to span a large part of the last glacial period and the holocene extending the available record of past vegetation and environments from the region by some 25 000 years to around 75 000 yr b p conditions during the earlier part of the last glacial period were cooler and drier than today with open casuarina woodland predominating in the region at times particularly towards the end of this period conditions are considered to have been more extreme as much of the pollen is oxidised a major interstadial whose termination is tentatively dated at about 48 000 yr b p was dominated by eucalyptus forest under effective precipitation levels similar to those of today the latter part of the last glacial period is considered to have been cold and dry although no pollen is preserved except during a short phase of amelioration probably around 39 000 yr b p the holocene has been characterised by mixed casuarina and eucalyptus woodland and forest until recent changes brought about by european people fire has been a constant feature of the environment and its influence on changing vegetation patterns cannot be determined with certainty

coal fires revisited the wuda coal field in the aftermath of extensive coal fire research and accelerating extinguishing activities abstract the wuda coal mining area in inner mongolia autonomous region china is one of the largest coal fire areas world wide at the same time it is also one of the most extensively researched ones the sub surface coal fires raging in the underground coal seams of the syncline are located directly west of the town of wuda the fires have been mapped in situ based on remote sensing data as well as based on geo physical survey all throughout the years 2001 to 2005 numerous publications depict the situation during that time in the present study we assess the current situation in wuda coal field five years after the last field campaigns under nowadays on going and accelerating extinguishing activities we present the results of coal fire dynamics assessment based on in situ mappings between 2004 and 2010 the analyses of changes in mining infrastructure between 2005 and 2012 as well as land cover change in the area from 2005 to 2012 newest high resolution multispectral and panchromatic quickbird data as well as time series of quickbird data supported this endeavor we furthermore present the result of semi structured interviews undertaken with members of the local mine directorate of the wuda syncline all jointly analyzed data indicate that the wuda coal fires tend to move eastwards within the syncline meaning that they move along the dip of the coal seams to greater depths furthermore mining related infrastructure is clearly moving from the west to the east as well despite large funds spent on fire extinguishing only few fires remain permanently extinct while other fire areas increase in size the former land cover structure in the arid syncline does not exist anymore extinguishing activities have led to a complete turn over of all material in the region the coal fire problem in wuda area remains a pressing one

a late pleistocene and holocene vegetation and environmental record from lake wangoom western plains of victoria australia abstract pollen microfaunal and sedimentological evidence from the top 20 m of sediment in a closed volcanic crater lake is used to construct a detailed record of vegetation and environmental conditions through the holocene and a substantial part of the late pleistocene radiocarbon dating suggests that the sequence covers tha last 51 000 yr or so high lake levels and the presence of forest or woodland vegetation indicate that the holocene and the basal few thousand years of the record experienced wet and warm conditions the earliest period was succeeded by a long phase of lower but variable moisture levels before more arid conditions resulted in the replacement of forest and woodland by herbaceous vegetation and frequent lake drying periods of slight amelioration occurred between about 27 000 and 19 000 and before 15 000 radiocarbon yr ago maximum aridity occurred between about 19 000 and 10 000 yr b p a period incorporating the height of the last glacial during the pleistocene the lake became gradually more saline but has been fresh during the holocene even under low lake levels an increase in charcoal values is recorded probably around 20 000 years ago and this could have resulted from increased burning as a result of the activities of aboriginal people this may have also caused a change in understorey vegetation from one composed largely of asteraceae to grassland the record is compared with others from southeastern australia and there is good correspondence through the last 20 000 or 30 000 yr but before this problems of dating and the condensed nature of most sequences prevent detailed correlation

topography of the lunar south polar region implications for the size and location of permanently shaded areas we analyze clementine altimetry to constrain the size and location of proposed permanently shadowed regions in the vicinity of the lunar south pole long and short wavelength topography in the vicinity of the pole in combination with measurements of depths of well preserved craters and basins and the lunar topographic power spectrum have direct bearing on the nature of elevations in the south polar region a criterion based on geometric considerations and altimetry demonstrates that the existence of permanent shadowing is not very sensitive to the elevation of the south pole in addition permanent shadowing cannot be a consequence of large structures such as the south pole aitken basin and or a 300 km degraded polar basin perennially dark regions if they exist are most likely associated with craters or other axisymmetric features with diameters of at most 80 km centered at the pole for structures displaced 2 from the pole the maximum allowable diameter decreases to 30 km

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

the southern hemisphere westerlies in the australasian sector over the last glacial cycle a synthesis abstract the southern hemisphere westerlies in the southwest pacific are known to have waxed and waned numerous times during the last two glacial cycles though even semi continuous histories of the westerlies extend back no more than about 20 000 years we have good evidence for at least three scales of events a westerly maximum occurs at the last glacial maximum there is less conclusive evidence for another westerly maximum in the late holocene and for a minimum at ca 11 ka it is too early to ascribe even a cycle to these data but there are grounds to suggest that milankovitch precessional forcing may underlie the observed pattern there is also a quasi 2600 year cycle present in antarctic ice cores that appears to correlate to variation in westerly flow there is strong centennial scale variability in historical times the little ice age lia ca 1400 1850 was associated with a poleward shift in the circumpolar trough in the southern ocean strengthened westerly circulation over tasmania and a strengthening of southwesterly circulation and neoglaciation in southern new zealand while the preceding period 800 1400 ad was less certainly marked by reduced westerly flow from modern records we know that decadal and inter annual variability is important e g pacific decadal oscillation high latitude mode also known as the antarctic oscillation el nino southern oscillation only a minority of the proxies examined can identify changes on these temporal scales but data from tree rings ice cores and laminated lake sediments do indicate systematic changes in these phenomena through time rossby wave patterns are shown to play a critical role in long duration events as well as at the synoptic scale we conclude that westerly circulation is as strong now as at any time in the last glacial cycle in addition changes in latitudinal boundaries in the westerlies may be nearly as large in inter annual zonal shifts ca 2 maximum as in glaciation interglaciation movements ca 3 4 there is however reasonable evidence of strengthening weakening across much of the westerly belt at westerly maxima minima such as the lia early holocene

geomorphologic mapping of the lunar crater tycho and its impact melt deposits abstract using selene kaguya terrain camera and lunar reconnaissance orbiter camera lroc data we produced a new high resolution 10 m pixel geomorphological and impact melt distribution map for the lunar crater tycho the distal ejecta blanket and crater rays were investigated using lroc wide angle camera wac data 100 m pixel while the fine scale morphologies of individual units were documented using high resolution 0 5 m pixel lroc narrow angle camera nac frames in particular tycho shows a large coherent melt sheet on the crater floor melt pools and flows along the terraced walls and melt pools on the continuous ejecta blanket the crater floor of tycho exhibits three distinct units distinguishable by their elevation and hummocky surface morphology the distribution of impact melt pools and ejecta as well as topographic asymmetries support the formation of tycho as an oblique impact from the w sw the asymmetric ejecta blanket significantly reduced melt emplacement uprange and the depressed uprange crater rim at tycho suggest an impact angle of 25 45

a fine resolution palaeoclimatic reconstruction of the last 2000 years from lake keilambete southeastern australia a fine resolution analysis of pollen charcoal magnetic susceptibility sediment fractions and total carotenoids was used to investigate the last 2000 years of environmental history at lake keilambete in western victoria australia the chronology of sedimentation was based on three radiocarbon dates supplemented by inferences from 22 previous radiocarbon ages from the site spanning approximately the last 7500 years changes in the analysed parameters infer a relatively higher effective moisture from approximately 2000 to 1800 cal bp increased instability in the lake keilambete catchment from 1750 to 1425 cal bp may reflect a decreased moisture availability and cooler temperatures at about 1450 cal bp a period of considerable environmental change is suggested at lake keilambete warmer temperatures or an increased moisture supply seem likely between 1415 and 1320 cal bp from around c 1150 until 800 cal bp overlapping the medieval warm period a series of changes in the composition of the la

geologic remote sensing remote sensing techniques are now being used routinely in geologic interpretation for mineral and energy exploration plant siting waste disposal and the development of models for regional and continental tectonics new spaceborne methods and associated technologies are being developed to produce data from which geologic information about large areas can be derived much more rapidly than by conventional techniques

radar mapping of mercury s polar anomalies ground based radar observations of mercury have revealed unusually strong highly depolarized echoes from the north1 2 and south2 poles these anomalous echoes have been cited as evidence of polar ice deposits1 5 thermal studies3 5 suggest that the permanently shaded floors of large polar craters are cold enough to preserve water ice in a stable state over aeons in spite of mercury s proximity to the sun here we present high resolution radar maps of mercury s polar regions derived from delay doppler measurements we have resolved the north and south polar anomalies into numerous crater sized features and we have been able to identify the source craters for many of these features after making small corrections to the pole positions on the mariner 10 images the coincidence with crater locations together with other properties of the radar features are consistent with the polar ice hypothesis

analysis of mid infrared spectral characteristics of rock outcrops and an evaluation of the kahle model in predicting outcrop thermal inertias abstract this paper summarizes the results of an analysis of emissive spectra acquired at wavelengths of 8 2 13 6 m from multiple targets on granite amphibolite and calcareous marble outcrops in the clare river synform near tweed ontario prominent spectral features are noted for all three rock types the effects of surface contaminants such as lichens are examined results indicate that many of the diagnostic spectral features in granite although damped remain apparent in surfaces with as much as 71 lichen cover cloud cover is also shown to have a significant damping effect on the emissive spectrum spectral measurements were carried out in support of an experiment to investigate the accuracy with which the kahle 1977 numerical model can be used to predict the thermal inertia of rock outcrops in situ diurnal surface temperature differences were computed from emission spectra of selected targets on each rock outcrop the surface temperatures as well as meteorological data were inputs to the model predicted values from the model were then compared against measured thermal inertias from rock cores removed from each spectral target results indicate a mean overestimate in the model s thermal inertia of 25 a major contributing factor may be inherent errors in the model itself the model is shown to be quite sensitive to errors in the estimate of the surface albedo as well as the diurnal range in surface temperature