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Sample records for weathered rock

  1. Space Weathering of Rocks

    NASA Technical Reports Server (NTRS)

    Noble, Sarah

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

  2. Weathering of rock 'Ginger'

    NASA Technical Reports Server (NTRS)

    1997-01-01

    One of the more unusual rocks at the site is Ginger, located southeast of the lander. Parts of it have the reddest color of any material in view, whereas its rounded lobes are gray and relatively unweathered. These color differences are brought out in the inset, enhanced at the upper right. In the false color image at the lower right, the shape of the visible-wavelength spectrum (related to the abundance of weathered ferric iron minerals) is indicated by the hue of the rocks. Blue indicates relatively unweathered rocks. Typical soils and drift, which are heavily weathered, are shown in green and flesh tones. The very red color in the creases in the rock surface correspond to a crust of ferric minerals. The origin of the rock is uncertain; the ferric crust may have grown underneath the rock, or it may cement pebbles together into a conglomerate. Ginger will be a target of future super-resolution studies to better constrain its origin.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  3. Space Weathering of Lunar Rocks

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2012-01-01

    All materials exposed at the lunar surface undergo space weathering processes. On the Moon, boulders make up only a small percentage of the exposed surface, and areas where such rocks are exposed, like central peaks, are often among the least space weathered regions identified from remote sensing data. Yet space weathered surfaces (patina) are relatively common on returned rock samples, some of which directly sample the surface of larger boulders. Because, as witness plates to lunar space weathering, rocks and boulders experience longer exposure times compared to lunar soil grains, they allow us to develop a deeper perspective on the relative importance of various weathering processes as a function of time.

  4. Rock strength reductions during incipient weathering

    NASA Astrophysics Data System (ADS)

    Kelly, P. J.; Anderson, S. P.; Blum, A.

    2012-12-01

    Patrick Kelly, Suzanne Anderson, Alex Blum In rock below the surface, temperature swings are damped, water flow is limited, and biota are few. Yet rock weathers, presumably driven by these environmental parameters. We use rock strength as an indicator of rock weathering in Gordon Gulch in the Boulder Creek Critical Zone Observatory, a watershed at 2500 m underlain by Proterozoic gneiss intruded by the Boulder Creek granodiorite. Fresh rock is found at depths of 8-30 m in this area, and the thickness of the weathered rock zone imaged with shallow seismic refraction is greater on N-facing slopes than S-facing slopes (Befus et al., 2011, Vadose Zone J.). We use the Brazilian splitting test to determine tensile strength of cores collected with a portable drilling rig. Spatial variations in rock strength that we measure in the top 2 m of the weathered rock mantle can be connected to two specific environmental variables: slope aspect and the presence of a soil mantle. We find weaker rock on N-facing slopes and under soil. There is no clear correlation between rock strength and the degree of chemical alteration in these minimally weathered rocks. Denudation rates of 20-30 microns/yr imply residence times of 105-106 years within the weathered rock layers of the critical zone. Given these timescales, rock weathering is more likely to have occurred under glacial climate conditions, when periglacial processes prevailed in this non-glaciated watershed. Incipient weathering of rock appears to be controlled by water and frost cracking in Gordon Gulch. Water is more effectively delivered to the subsurface on N-facing slopes, and is more likely held against rock surfaces under soil than on outcrops. These moisture conditions, and the lower surface temperatures that prevail on N-facing slopes also favor frost cracking as an important weathering process.

  5. Rock weathering and Carbon cycle

    NASA Astrophysics Data System (ADS)

    Strozza, Patrick

    2010-05-01

    In the history of the Earth system, we can find indicators of hot or glacial periods, as well as brutal climatic change… How can we explain those climate variations on a geological timescale ? One of the causative agents is probably the fluctuation of atmospheric CO2 amounts, (gas responsible for the greenhouse effect). A concrete study of some CO2 fluxes between Earth system reservoirs (atmo, hydro and lithosphere) is proposed in this poster. Hydrogencarbonate is the major ion in river surface waters and its amount is so high that it can not be explained by a simple atmospheric Carbon diffusion. From a simple measurement of river HCO3- concentration, we can estimate the consumption of atmospheric CO2 that arises from carbonate and silicate weathering processes. Practical experiments are proposed. These are carried out in the local environment, and are conform to the curriculums of Chemistry and Earth sciences. These tests enable us to outline long-term Carbon cycles and global climatic changes. Key words : Erosion, rock weathering, CO2 cycle, Hydrogencarbonate in waters, climatic changes

  6. The Weathering of Rocks: Three Activities.

    ERIC Educational Resources Information Center

    McLure, John W.

    1991-01-01

    Integrates science and social studies in several activities that study weathering caused by the freezing and thawing of rocks, wind erosion, and the effects of weathering on tombstones. Cites the possibility of these activities leading to an interdisciplinary exploration of pollution, customs, and populations. (MCO)

  7. Deeply weathered basement rocks in Norway

    NASA Astrophysics Data System (ADS)

    Bönner, Marco; Knies, Jochen; Fredin, Ola; Olesen, Odleiv; Viola, Giulio

    2014-05-01

    Recent studies show that, in addition to tectonic processes, surface processes have also had a profound impact on the topography of Norway. This is especially obvious for the northernmost part of the Nordland county and for western Norway, where the current immature Alpine-type topography cannot be easily explained by tectonic processes only. Erosion of the sedimentary succession also does not seem sufficient to explain the observed relief. Common remnants of deeply weathered basement rocks, however, indicate a history of deep alteration and later erosion of the bedrock, which needs to be considered as another important factor in the development of the topographic relief. Most of the sites with deeply weathered basement exhibit a clay-poor grussy type of weathering, which is generally considered to be of relatively young age (Plio-/Pleistocene) and thought to represent an intermediate stage of weathering. Unfortunately, small amounts or complete absence of clay minerals in these weathering products precluded the accurate dating of this weathered material. Scandinavia was exposed to a large range of glaciations and the once extensive sedimentary successions have been almost entirely eroded, which impedes a minimum age estimate of the weathering profile. Although several sites preserving remnants of deep weathering can still be observed onshore Norway, they are all covered by Quaternary overburden and the age of the regolith remains thus unconstrained and a matter of debate. The only exception is a small Mesozoic basin on Andøya, northern Norway, where weathered and clay-poor saprolite was found underlying Jurassic and Cretaceous sedimentary rocks. Over the last few years the Geological Survey of Norway (NGU) has mapped and investigated deep weathering onshore Norway to better understand weathering processes and to constrain the age of the weathering remnants. The combined interpretation of geophysical, mineralogical and geochemical data, together with recent

  8. Building Stone and Its Use in Rock Weathering Studies.

    ERIC Educational Resources Information Center

    Dragovich, Deirdre

    1979-01-01

    Building stone provides opportunities for geological study of weathering of different rocks in a particular environment and similar rocks in different environment. The principle studied can be applied on a large scale from the observation of small-scale weathering. Examples of weathering are drawn mainly from the Sydney region of Australia. (RE)

  9. Take a Tumble: Weathering and Erosion Using a Rock Tumbler

    ERIC Educational Resources Information Center

    Coffey, Patrick; Mattox, Steve

    2006-01-01

    Weathering--the physical and chemical breakdown of geologic materials--and erosion--the transport of materials by wind, water, or ice--can be subtle, yet powerful forces. For example, shale, a rock made of mud-sized particles, is by far the most common sedimentary rock, a testament to the ability of weathering and erosion to take a rock and reduce…

  10. Rock-weathering rates as functions of time

    USGS Publications Warehouse

    Colman, Steven M.

    1981-01-01

    The scarcity of documented numerical relations between rock weathering and time has led to a common assumption that rates of weathering are linear. This assumption has been strengthened by studies that have calculated long-term average rates. However, little theoretical or empirical evidence exists to support linear rates for most chemical-weathering processes, with the exception of congruent dissolution processes. The few previous studies of rock-weathering rates that contain quantitative documentation of the relation between chemical weathering and time suggest that the rates of most weathering processes decrease with time. Recent studies of weathering rinds on basaltic and andesitic stones in glacial deposits in the western United States also clearly demonstrate that rock-weathering processes slow with time. Some weathering processes appear to conform to exponential functions of time, such as the square-root time function for hydration of volcanic glass, which conforms to the theoretical predictions of diffusion kinetics. However, weathering of mineralogically heterogeneous rocks involves complex physical and chemical processes that generally can be expressed only empirically, commonly by way of logarithmic time functions. Incongruent dissolution and other weathering processes produce residues, which are commonly used as measures of weathering. These residues appear to slow movement of water to unaltered material and impede chemical transport away from it. If weathering residues impede weathering processes then rates of weathering and rates of residue production are inversely proportional to some function of the residue thickness. This results in simple mathematical analogs for weathering that imply nonlinear time functions. The rate of weathering becomes constant only when an equilibrium thickness of the residue is reached. Because weathering residues are relatively stable chemically, and because physical removal of residues below the ground surface is slight

  11. On the weathering of Martian igneous rocks

    NASA Technical Reports Server (NTRS)

    Dreibus, G.; Waenke, H.

    1992-01-01

    Besides the young crystallization age, one of the first arguments for the martian origin of shergottite, nakhlite, and chassignite (SNC) meteorites came from the chemical similarity of the meteorite Shergotty and the martian soil as measured by Viking XRF analyses. In the meantime, the discovery of trapped rare gas and nitrogen components with element and isotope ratios closely matching the highly characteristic ratios of the Mars atmosphere in the shock glasses of shergottite EETA79001 was further striking evidence that the SNC's are martian surface rocks. The martian soil composition as derived from the Viking mission, with its extremely high S and Cl concentrations, was interpreted as weathering products of mafic igneous rocks. The low SiO2 content and the low abundance of K and other trace elements in the martian soils point to a mafic crust with a considerably smaller degree of fractionation compared to the terrestrial crust. However, the chemical evolution of the martian regolith and soil in respect to surface reaction with the planetary atmosphere or hydrosphere is poorly understood. A critical point in this respect is that the geochemical evidence as derived from the SNC meteorites suggests that Mars is a very dry planet that should have lost almost all its initially large water inventory during its accretion.

  12. Characterizing and modelling 'ghost-rock' weathered limestones

    NASA Astrophysics Data System (ADS)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  13. Physical and chemical weathering. [of Martian surface and rocks

    NASA Technical Reports Server (NTRS)

    Gooding, James L.; Arvidson, Raymond E.; Zolotov, Mikhail IU.

    1992-01-01

    Physical and chemical weathering processes that might be important on Mars are reviewed, and the limited observations, including relevant Viking results and laboratory simulations, are summarized. Physical weathering may have included rock splitting through growth of ice, salt or secondary silicate crystals in voids. Chemical weathering probably involved reactions of minerals with water, oxygen, and carbon dioxide, although predicted products vary sensitively with the abundance and physical form postulated for the water. On the basis of kinetics data for hydration of rock glass on earth, the fate of weathering-rind formation on glass-bearing Martian volcanic rocks is tentatively estimated to have been on the order of 0.1 to 4.5 cm/Gyr; lower rates would be expected for crystalline rocks.

  14. Subsurface Weathering of Rocks and Soils at Gusev Crater

    NASA Technical Reports Server (NTRS)

    Yen, A. S.; Ming, D. W.; Gellert, R.; Clark, B. C.; Morris, R. V.; Rodionov, D.; Schroeder, C.

    2005-01-01

    Data collected by the Mars Exploration Rover (MER) Spirit at Gusev Crater suggest that enhanced weathering of rocks and soils occurs beneath the immediate surface. We suggest that this alteration occurs over geological timescales under present climatic conditions and is a result of diurnal condensation of thin-films of water on subsurface materials. Additional information is included in the original extended abstract.

  15. Evidence for non-Gaussian distribution of rock weathering rates

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.

    2015-07-01

    The weathering of rocks influences the geochemistry of the oceans, the erosion of landscapes and manmade structures, and even the global climate. Although a high degree of variance is often observed in rate measurements, little is understood about the statistical characteristics of weathering rate distributions. This preliminary study demonstrates that the weathering rates of limestone, determined from measurements of an ancient eroded limestone edifice, can exhibit highly non-Gaussian behavior. While a Gaussian model produced a poor fit with the data, an alternative model - the generalized extreme value (GEV) framework - was capable of capturing the asymmetric long tailed distribution, in good agreement with the measured curve. Furthermore, the non-Gaussian distribution of these field rates was found to have similar characteristics to the distribution of rates measured over much smaller microscopic regions of limestone surfaces in laboratory experiments. Such similar behavior could be indicative of analogous chemical and mechanical weathering processes acting over a range of different spatial and temporal scales. Moreover, highly asymmetric rate distributions with high variance could be characteristic of rates not only in carbonate rocks, but in other rock types too, suggesting that the use of a small number of measurements to determine field weathering rates may be insufficient to fully characterize the range of rates in natural systems.

  16. Association of trace elements with iron oxides during rock weathering

    SciTech Connect

    Koons, R.D.; Helmke, P.A.; Jackson, M.L.

    1980-01-01

    The association of trace elements with Fe oxides during the early stages of rock weathering was determined by analysis of fresh diabase and granite rocks, their associated whole and size-separated saprolites, and goethite by neutron activation and X-ray fluorescence. The same elements are found to be associated with Fe oxides when the results are interpreted by analysis of correlation, by the distribution of elements in the various size fractions by the effects of removing free Fe oxides, and by direct analysis of geothite from the saprolite. The elements Co, Cr, Mn, Sc, Th, U, Zn, and the heavy rare-earth elements during the weathering of diabase, and As, Co, Cr, Sc, Th, U, Zn, and the heavy rare-earth elements during the weathering of granite are associated with Fe oxides. The concentrations of Mn are too low in this system to separate the effects of Mn oxides from those of Fe oxides.

  17. Modelling study on uranium migration in rocks under weathering condition

    SciTech Connect

    Ohnuki, Toshihiko; Isobe, Hiroshi; Sato, Tsutomu; Yanase, Nobuyuki; Murakami, Takashi

    1995-12-31

    A modelling study has been completed to understand the effect of rock alteration on uranium migration at the Koongarra ore deposit, Australia. The model considers the weathering process, the mechanism and rate of chlorite alteration, a major mineral of the host rock, and assumes the presence of reversible sorption sites of chlorite and the presence of reversible and irreversible sorption sites of the weathering products. One- and two-dimensional, calculated uranium concentrations were compared with those observed. Good agreement between the calculated and observed uranium concentration profiles was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of Fe-minerals produced during weathering of chlorite. On the other hand, the conventional Kd model failed to estimate an adequate uranium concentration profile. The results suggest that the fixation of uranium to Fe-minerals has dominated the migration of uranium in the vicinity of the Koongarra ore deposit.

  18. Rock Rinds at Meridiani and Surface Weathering Phenomena

    NASA Astrophysics Data System (ADS)

    Jolliff, B.; Knoll, A.; Farrand, W.; Sullivan, R.

    2006-12-01

    The Rock Abrasion Tool (RAT) on the Mars rover Opportunity can brush away surface dust and grind away outcrop surface, exposing presumably less altered rock at depths of several mm. Alpha particle X-ray spectrometer (APXS) and Moessbauer spectrometer (MB) analyses of pre- and post-RAT targets, thus, provide information on the chemical nature of weathering of Meridiani outcrop rocks. To date, Opportunity has analyzed some 25 undisturbed rock surfaces, brushed and then analyzed 7 more, and ground 23 targets for IDD analysis. Panoramic camera images show that outcrop surfaces are typically either buff or purple (as viewed in bands centered at 673, 535, and 432 nm, Farrand et al., JGR, in press). Relatively flat surfaces that are approximately parallel to the ground are typically buff, whereas those that slope steeply tend to be purple. Surfaces of rock interiors ground by the RAT are also commonly purple. Spectrally, these color differences correspond to more oxidized (buff) and less oxidized (purple), and appear to relate to the degree of eolian abrasion. Flat-lying surfaces are not eroded as quickly, thus surfaces chemically weathered by exposure to tenuous atmospheric vapor may be preserved. These observations are consistent with in-situ analyses of rock surfaces and interiors. Compared to interiors, rock surfaces have about 1/3 less S, and in general, surface compositions lie between those of rock interiors and average surface soil. In detail, they differ from soil-rock mixtures as follows: surfaces are relatively depleted in Mg, Fe, Mn, Ti, and Cr, and they are enriched in Al, Na, K, P, Cl, and Si. From MB analyses, surfaces are richer (compared to soil-rock mixtures) in oxidized Fe phases and poorer in magnetite, olivine, and pyroxene. Morphologically, numerous flat-lying rocks and outcrop surfaces that are at or near the ground surface have a rind of erosionally resistant material. Such rinds are also chemically distinct from outcrop interiors. A rind

  19. Weathered stony meteorites from Victoria Land, Antarctica, as possible guides to rock weathering on Mars

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1984-01-01

    Parallel studies of Martian geomorphic features and their analogs on Earth continue to be fruitful in deciphering the geologic history of Mars. In the context of rock weathering, the Earth-analog approach is admirably served by the study of meteorites recovered from ice sheets in Antarctica. The weathering environment of Victoria Land possesses several Mars-like attributes. Four of the five Antarctic meteorites being studied contain rust and EETA79005 further possesses a conspicuous, dark, weathering rind on one side. Secondary minerals (rust and salts) occur both on the surfaces and interiors of some of the samples and textural evidence indicates that such secondary mineralization contributed to physical weathering (by salt riving) of the rocks. Several different rust morphologies occur and emphasis is being placed on identifying the phase compositions of the various rust occurrances. A thorough understanding of terrestrial weathering features of the meteorites is a prerequisite for identifying possible Martian weathering features (if such features exist) that might be postulated to occur in some meteorites.

  20. Space Weathering of Lunar Rocks and Regolith Grains

    NASA Technical Reports Server (NTRS)

    Keller, L. P.

    2013-01-01

    The exposed surfaces of lunar soil grains and lunar rocks become modified and coated over time with a thin rind of material (patina) through complex interactions with the space environment. These interactions encompass many processes including micrometeorite impacts, vapor and melt deposition, and solar wind implantation/sputtering effects that collectively are referred to as "space weathering". Studies of space weathering effects in lunar soils and rocks provide important clues to understanding the origin and evolution of the lunar regolith as well as aiding in the interpretation of global chemical and mineralogical datasets obtained by remote-sensing missions. The interpretation of reflectance spectra obtained by these missions is complicated because the patina coatings obscure the underlying rock mineralogy and compositions. Much of our understanding of these processes and products comes from decades of work on remote-sensing observations of the Moon, the analysis of lunar samples, and laboratory experiments. Space weathering effects collectively result in a reddened continuum slope, lowered albedo, and attenuated absorption features in reflectance spectra of lunar soils as compared to finely comminuted rocks from the same Apollo sites. Space weathering effects are largely surface-correlated, concentrated in the fine size fractions, and occur as amorphous rims on individual soil grains. Rims on lunar soil grains are highly complex and span the range between erosional surfaces modified by solar wind irradiation to depositional surfaces modified by the condensation of sputtered ions and impact-generated vapors. The optical effects of space weathering effects are directly linked to the production of nanophase Fe metal in lunar materials]. The size of distribution of nanophase inclusions in the rims directly affect optical properties given that large Fe(sup o) grains (approx 10 nm and larger) darken the sample (lower albedo) while the tiny Fe(sup o) grains (<5nm

  1. Generalized soil Thaumarchaeota community in weathering rock and saprolite.

    PubMed

    Dong, Ke; Kim, Woo-Sung; Tripathi, Binu Mani; Adams, Jonathan

    2015-02-01

    Relatively little is known of the archaeal communities associated with endolithic environments, compared to other microbial groups such as bacteria and fungi. Analyzing the pyrosequenced archaeal 16S ribosomal RNA (rRNA) gene V1-V3 region, we investigated the archaeal community associated with aboveground-exfoliated weathering layers of a granite gneiss, and of the saprolite derived from this rock at 1 m depth below the soil surface, in a forested hilly area south of Seoul, South Korea. In both these sites, an archaeal community dominated by the phylum Thaumarchaeota was identified. The archaeal community in all cases closely resembled that of the surface layer of acidic soils in temperate climates of Korea. It appears that there is no clear distinction in archaeal community composition between a soil and a rock and a saprolite despite a tremendous difference in the concentration of total nitrogen and organic carbon. Of the chemical properties we measured, pH was the best predictor of the archaeal community composition and relative abundance of thaumarchaeal subphyla. These findings reinforce the view that soil archaea are mostly generalists, whose ecology is not closely dependent on nitrogen concentration or soil organic matter status, the presence of living roots, or the abundant presence of any other biota. PMID:25370886

  2. Effects of Weathering on Basaltic Rocks and Their Thermal Emission Spectra: Implications for Evaluating Mars Mineralogy and Weathering

    NASA Astrophysics Data System (ADS)

    Kraft, M. D.; Michalski, J. R.; Sharp, T. G.

    2005-12-01

    Thermal emission spectroscopy has provided crucial information about the mineralogical composition of the Martian surface. Portions of that surface may be chemically weathered, and it is, therefore, important that the influence of chemical weathering on thermal infrared observations be recognized and understood. To this end, we have examined a suite of weathered rocks collected from the Columbia River Basalt Group. Weathering causes distinct changes to the thermal emissivity spectra of these basalts, which will be discussed in detail by J. R. Michalski et al. (this meeting). Here, we document physical and mineralogical features of weathering rinds to understand how weathering affects infrared spectra. Chemical weathering of basalts forms microcracks, dissolves primary minerals, and produces secondary phases. In the rocks examined, the relative abundance of primary minerals is the same in the weathering rind and corresponding unweathered rock. This is true even for olivine, the least stable phase in the rocks studied. Thus, preferential dissolution is not a controlling factor in the observed spectral changes. Microcracks form by expansion and dissolution and represent <20 vol% of the weathering rinds studied. While they potentially act as blackbody cavities, they probably influence emissivity spectra more by acting as sites where secondary phases form. Because the cracks are generally a few micrometers in width, the secondary phases filling them are optically thin, which may produce nonlinearity in spectral mixing of mineral phases, complicating spectral modeling. Secondary phases are Si-Al-rich and strongly influence the Si-O stretching region of infrared spectra. Dissolution of silica from primary phases and its precipitation in microcracks are the principle factors controlling changes in emissivity spectra in weathered rocks. These changes can lead to inaccurate relative abundances of primary phases derived from deconvolution modeling of weathered rocks. Also

  3. Field Guide to Rock Weathering. Earth Science Curriculum Project Pamphlet Series PS-1.

    ERIC Educational Resources Information Center

    Boyer, Robert E.

    Highlighted are the effects of weathering through field investigations of the environment, both natural rocks, and the urban environment's pavements, buildings, and cemeteries. Both physical weathering and chemical weathering are discussed. Questions are presented for post-field trip discussion. References and a glossary are provided. (Author/RE)

  4. New weathering indices for evaluating durability and weathering characterization of crystalline rock material: A case study from NE Turkey

    NASA Astrophysics Data System (ADS)

    Ceryan, Sener

    2015-03-01

    There are several methods to characterize petrochemical properties of crystalline rocks. One method is based on the ionic model. In the model, large oxygen atoms of the rock-forming minerals are close-packed framework structures. The distribution of cations, which is defined by the "Cation-Packing Index" or the k-value for each (stoichiometric) mineral phase, can be correlated with the petrophysical properties. These properties, representing the engineering behavior of the rock materials show a dependence on the physical and chemical changes due to weathering. The fundamental systems of the chemical weathering of rocks are the leaching of the alkaline and alkali-earth elements and the redistribution of the residual elements into secondary minerals. In this study, these conditions are considered as the basis for new petro-chemical weathering indices based on the cation-packing value for evaluating weathering characterization of crystalline rocks. These indices are the k-product index, the k-leaching index and the k-weathering index. The k-product index represents the quantity of the weathering product suggested in this study, whereas the k-leaching index represents the amount of chemical leaching during the weathering. The k-weathering index was defined as the sum of the k-leaching index and the k-product index. In addition to these new engineering indices, a k-durability index based on a slake durability index and the k-value of the rock materials was suggested in this study to estimate the durability and the mechanical properties of rock materials. These indices were applied to granitic rock samples weathered to various degrees, from the Kurtun Granodiorite in northeastern Turkey. The results of the regression analysis performed in this study show that the k-weathering index can be used as a weathering indicator and that the k-durability index can be used to evaluate the durability and the mechanical behaviors of the investigated samples. It would be useful to

  5. Chitinophaga qingshengii sp. nov., isolated from weathered rock surface.

    PubMed

    Cheng, Cheng; Wang, Qi; He, Lin-Yan; Huang, Zhi; Sheng, Xia-Fang

    2015-01-01

    A novel mineral-weathering bacterium was isolated from weathered rock (potassic trachyte) surfaces collected from Nanjing (Jiangsu, PR China). Cells of strain JN246(T) were Gram-stain-negative, rod-shaped and non-motile. Strain JN246(T) was aerobic, catalase- and oxidase-positive, and grew optimally at 28 °C and pH 7.0. On the basis of 16S rRNA gene sequence analysis, strain JN246(T) belonged to the genus Chitinophaga and the closest phylogenetic relatives were Chitinophaga eiseniae YC6729(T) (98.5% 16S rRNA gene sequence similarity), Chitinophaga terrae KP01(T) (96.8%), and Chitinophaga jiangningensis JN53(T) (96.3 %). The major respiratory quinone was MK-7 and the major polyamine was homospermidine. The major fatty acids were iso-C15:0, C16:1ω5c, C16:0 and iso-C17:0 3-OH. The polar lipid profile of strain JN246(T) consisted of phosphatidylethanolamine, unknown aminolipids and unknown lipids. The genomic DNA G+C content of strain JN246(T) was 48.8 mol%. Based on the low level of DNA-DNA relatedness of strain JN246(T) (ranging from 22.6% to 42.4%) to the type strains of other species of the genus Chitinophaga and unique phenotypic characteristics, strain JN246(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga qingshengii sp. nov. is proposed. The type strain is JN246(T) ( = CCTCC AB 2014201(T) = JCM 30026(T)). PMID:25342110

  6. Weathering of expansive sedimentary rock due to cycles of wetting and drying

    SciTech Connect

    Day, R.W. )

    1994-09-01

    There are several different mechanisms by which sedimentary rock can weather, such as: (1) Rebound: for cut areas, where the overburden has been removed by erosion or during mass-grading operations, the sedimentary rock will rebound due to the release in overburden pressure, the rebound can cause the opening or widening of cracks and joints; (2) Physical Weathering: sedimentary rock can be broken apart by the physical growth of plant roots or by the freezing of water in rock cracks or joints. Studies have also shown that precipitation of gypsum in rock pores, cracks, and joints can cause rock expansion and disintegration. Such conditions occur in arid climates where subsurface moisture evaporates at ground surface, precipitating the minerals in the rock pores. Acicular gypsum crystals have been observed to grow perpendicular to structures and are believed to exert the most force at their growing end (Hawkins and Pinces, 1987). Acicular gypsum growth has even been observed in massive sandstone, which resulted in significant heave (Hollingsworth and Grover, 1992); (3) Chemical Weathering: weathering of sedimentary rock can be due to oxidation, hydration of clay minerals, and the chemical alteration of the silt-size particles to clay. Factors affecting oxidation include the presence of moisture and oxygen (aerobic conditions), biological activity, acidic environment, and temperature (Hollingsworth and Grover, 1992). The purpose of this study was to investigate the weathering of expansive sedimentary rock due to cycles of wetting and drying at temperatures representative of field conditions.

  7. An Examination of the Space Weathering Patina of Lunar Rock 76015

    NASA Technical Reports Server (NTRS)

    Noble, S.; Chrisoffersen, R.; Rahman, Z.

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied under SEM and also by TEM using ultramicrotome sample preparation methods. However, to really understand the products involved in creating these coatings, it is helpful to examine the patina in cross section, something which is now possible though the use of Focused Ion Beam (FIB) sample prep techniques, which allows us to preserve intact the delicate stratigraphy of the patina coating and provides a unique cross-sectional view of the space weathering process. Several samples have been prepared from the rock and the coatings are found to be quite variable in thickness and composition from one sample to the next.

  8. The effect of rock composition on cyanobacterial weathering of crystalline basalt and rhyolite.

    PubMed

    Olsson-Francis, K; Simpson, A E; Wolff-Boenisch, D; Cockell, C S

    2012-09-01

    The weathering of volcanic rocks contributes significantly to the global silicate weathering budget, effecting carbon dioxide drawdown and long-term climate control. The rate of chemical weathering is influenced by the composition of the rock. Rock-dwelling micro-organisms are known to play a role in changing the rate of weathering reactions; however, the influence of rock composition on bio-weathering is unknown. Cyanobacteria are known to be a ubiquitous surface taxon in volcanic rocks. In this study, we used a selection of fast and slow growing cyanobacterial species to compare microbial-mediated weathering of bulk crystalline rocks of basaltic and rhyolitic composition, under batch conditions. Cyanobacterial growth caused an increase in the pH of the medium and an acceleration of rock dissolution compared to the abiotic controls. For example, Anabaena cylindrica increased the linear release rate (R(i)(l)) of Ca, Mg, Si and K from the basalt by more than fivefold (5.21-12.48) and increased the pH of the medium by 1.9 units. Although A. cylindrica enhanced rhyolite weathering, the increase in R(i)(l) was less than threefold (2.04-2.97) and the pH increase was only 0.83 units. The R(i)(l) values obtained with A. cylindrica were at least ninefold greater with the basalt than the rhyolite, whereas in the abiotic controls, the difference was less than fivefold. Factors accounting for the slower rate of rhyolite weathering and lower biomass achieved are likely to include the higher content of quartz, which has a low rate of weathering and lower concentrations of bio-essential elements, such as, Ca, Fe and Mg, which are known to be important in controlling cyanobacterial growth. We show that at conditions where weathering is favoured, biota can enhance the difference between low and high Si-rock weathering. Our data show that cyanobacteria can play a significant role in enhancing rock weathering and likely have done since they evolved on the early Earth. PMID:22694082

  9. Microbial populations and activities in the rhizoplane of rock-weathering desert plants. I. Root colonization and weathering of igneous rocks.

    PubMed

    Puente, M E; Bashan, Y; Li, C Y; Lebsky, V K

    2004-09-01

    Dense layers of bacteria and fungi in the rhizoplane of three species of cactus (Pachycereus pringlei, Stenocereus thurberi, Opuntia cholla) and a wild fig tree (Ficus palmeri) growing in rocks devoid of soil were revealed by bright-field and fluorescence microscopy and field emission scanning electron microscopy. These desert plants are responsible for rock weathering in an ancient lava flow at La Purisima-San Isidro and in sedimentary rock in the Sierra de La Paz, both in Baja California Sur, Mexico. The dominant bacterial groups colonizing the rhizoplane were fluorescent pseudomonads and bacilli. Seven of these bacterial species were identified by the 16S rRNA molecular method. Unidentified fungal and actimomycete species were also present. Some of the root-colonizing microorganisms fixed in vitro N(2), produced volatile and non-volatile organic acids that subsequently reduced the pH of the rock medium in which the bacteria grew, and significantly dissolved insoluble phosphates, extrusive igneous rock, marble, and limestone. The bacteria were able to release significant amounts of useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn from the rocks and were thermo-tolerant, halo-tolerant, and drought-tolerant. The microbial community survived in the rhizoplane of cacti during the annual 10-month dry season. This study indicates that rhizoplane bacteria on cacti roots in rock may be involved in chemical weathering in hot, subtropical deserts. PMID:15375735

  10. Chitinophaga longshanensis sp. nov., a mineral-weathering bacterium isolated from weathered rock.

    PubMed

    Gao, Shan; Zhang, Wen-Bin; Sheng, Xia-Fang; He, Lin-Yan; Huang, Zhi

    2015-02-01

    A Gram-stain-negative, aerobic, yellow-pigmented, non-motile, non-spore-forming, rod-shaped bacterial strain, Z29(T), was isolated from the surface of weathered rock (potassic trachyte) from Nanjing, Jiangsu Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain Z29(T) belongs to the genus Chitinophaga in the family Chitinophagaceae. Levels of 16S rRNA gene sequence similarity between strain Z29(T) and the type strains of recognized species of the genus Chitinophaga ranged from 92.7 to 98.2 %. The main fatty acids of strain Z29(T) were iso-C15 : 0, C16 : 1ω5c and iso-C17 : 0 3-OH. It also contained menaquinone 7 (MK-7) as the respiratory quinone and homospermidine as the main polyamine. The polar lipid profile contained phosphatidylethanolamine, unknown aminolipids, unknown phospholipids and unknown lipids. The total DNA G+C content of strain Z29(T) was 51.3 mol%. Phenotypic properties and chemotaxonomic data supported the affiliation of strain Z29(T) with the genus Chitinophaga. The low level of DNA-DNA relatedness (ranging from 14.6 to 29.8 %) to the type strains of other species of the genus Chitinophaga and differential phenotypic properties demonstrated that strain Z29(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga longshanensis sp. nov. is proposed. The type strain is Z29(T) ( = CCTCC AB 2014066(T) = LMG 28237(T)). PMID:25376849

  11. Probing the Depths of Space Weathering: A Cross-sectional View of Lunar Rock 76015

    NASA Technical Reports Server (NTRS)

    Noble, Sarah K.; Keller, L. P.; Stroud, Rhonda

    2007-01-01

    The term "space weathering" refers to the cumulative effects of several processes operating at the surface of any solar system body not protected by a thick atmosphere. These processes include cosmic and solar ray irradiation, solar wind implantation and sputtering, as well as melting and vaporization due to micrometeorite bombardment. Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied using SEM and TEM. It is a noritic breccia with both "glazed" (smooth glassy) and "classic" (microcratered and pancake-bearing) patina coatings. Previous TEM work on 76015 relied on ultramicrotomy to prepare cross sections of the patina coating, but these sections were limited by the "chatter" and loss of material in these brittle samples. Here we have used a focused ion beam (FIB) instrument to prepare cross sections in which the delicate stratigraphy of the patina coating is beautifully preserved.

  12. Uranium thorium chronometry of weathering rinds: Rock alteration rate and paleo-isotopic record of weathering fluids

    NASA Astrophysics Data System (ADS)

    Pelt, E.; Chabaux, F.; Innocent, C.; Navarre-Sitchler, A. K.; Sak, P. B.; Brantley, S. L.

    2008-11-01

    The potential of 238U- 234U- 230Th chronometry for constraining the formation rate of weathering rinds developed on fresh rocks is assessed by analyzing a weathering rind on a basaltic clast from a 125 kyr old Costa Rican alluvial terrace. Eighteen subsamples were collected from one section of the clast by drilling cores (4 mm in diameter and 5 mm depth) along two transects straddling the core-rind boundary. Variations of major and trace element concentrations along the two transects point out (a) intense loss of alkaline and alkaline-earth elements, (b) conservative behaviour of elements such as Zr, Hf and Th, and (c) external input of U into the rind without any evidence of U loss during basalt weathering. In addition, variations in U concentrations along the transects show that the main U-Th fractionation process associated with the weathering of the basaltic clast is an external input of U (without addition nor loss of Th) in the basalt rind transition zone, and that, once deposited U is immobile in the weathering rind. In the frame of this interpretation scheme, a weathering rate of 0.5 ± 0.2 mm/kyr can be calculated for the studied clast, which is consistent with geological and isotopic evidence constraining the depositional ages of the terraces. In addition, the variations in the ( 234U/ 238U) ratio along the analysed transects as well as the increase in Sr isotopic ratios within the weathering rind are best explained by temporal variation of the U activity ratios and Sr isotope ratios of the soil solutions brought into the rind. This work highlights how well detailed U-Th chronological studies of weathering rinds can (1) constrain the formation rates of weathering systems, and (2) record the time variation of isotopic composition of weathering fluids.

  13. [Role of microscopic fungi in the process of weathering of pegmatite deposit rocks and minerals].

    PubMed

    Avakian, Z A; Karavaiko, G I; Mel'nikova, E O; Krutsko, V S; Ostroushko, Iu I

    1981-01-01

    The object of this work was to study the effect of microscopic fungi isolated from the weathering zone of a pegmatite deposit on the transport of elements and the degradation of rocks and minerals. Regardless of the chemical composition of rocks and minerals, microscopic fungi accelerated the leaching of elements as compared to the purely chemical process. The extraction of Li, Si, Al and Fe under the action of microorganisms increased by factors of 1.4-1.7, 2.7-4.0, 5.0-8.7 and 4-18, respectively. In the case of chemical weathering, the extraction of elements occurred at a high rate only at the beginning; then the process either decelerated or stopped. The mechanism of action of microscopic fungi on rocks and minerals is discussed as well as the role of these microorganisms in the weathering of spodumene and the surrounding rocks, pegmatites an shales, which occurs in the zone of hypergenesis. PMID:7194415

  14. Porosity and surface area evolution during weathering of two igneous rocks

    SciTech Connect

    Navarre-Sitchler, Alexis; Cole, David; Rother, Gernot; Jin, Lixin; Buss, Heather; Brantley, S. L.

    2013-01-01

    During weathering, rocks release nutrients and storewater vital for growth ofmicrobial and plant life. Thus, the growth of porosity as weathering advances into bedrock is a life-sustaining process for terrestrial ecosystems. Here, we use small-angle and ultra small-angle neutron scattering to show how porosity develops during initial weathering under tropical conditions of two igneous rock compositions, basaltic andesite and quartz diorite. The quartz diorite weathers spheroidally while the basaltic andesite does not. The weathering advance rates of the two systems also differ, perhaps due to this difference in mechanism, from 0.24 to 100 mm kyr1, respectively. The scattering data document how surfaces inside the feldspar-dominated rocks change as weathering advances into the protolith. In the unaltered rocks, neutrons scatter fromtwo types of featureswhose dimensions vary from6 nmto 40 lm: pores and bumps on pore grain surfaces. These features result in scattering data for both unaltered rocks that document multi-fractal behavior: scattering is best described by amass fractal dimension (Dm) and a surface fractal dimension (Ds) for features of length scales greater than and less than 1 lm, respectively. In the basaltic andesite, Dm is approximately 2.9 and Ds is approximately 2.7. The mechanism of solute transport during weathering of this rock is diffusion. Porosity and surface area increase from 1.5%to 8.5%and 3 to 23 m2 g1 respectively in a relatively consistent trend across themm-thick plagioclase reaction front. Across this front, both fractal dimensions decrease, consistentwith development of amoremonodisperse pore networkwith smoother pore surfaces. Both changes are consistent largely with increasing connectivity of pores without significant surface roughening, as expected for transport-limited weathering. In contrast, porosity and surface area increase from 1.3% to 9.5% and 1.5 to 13 m2 g1 respectively across a many cm-thick reaction front in the

  15. Geoelectric investigations into sandstone moisture regimes: Implications for rock weathering and the deterioration of San Rock Art in the Golden Gate Reserve, South Africa

    NASA Astrophysics Data System (ADS)

    Mol, L.; Viles, H. A.

    2010-06-01

    The Clarens sandstone in the Golden Gate Reserve, South Africa, is the canvas for a collection of San (Bushmen) Rock Art, dating from Neolithic times until as recently as 150 years ago. This Rock Art is under threat from human interference but also, to a greater degree, from weathering processes on the rock surface. The dominant weathering processes occurring in the rock shelters which host the Rock Art are flaking and honeycombing. Two rock shelter sites in the Reserve have been investigated using electric resistivity tomography (ERT) and supportive methods for measuring surface moisture (Protimeter) and surface hardness (Equotip). These non-destructive techniques can be used in situ to assess the extent of weathering within a rock outcrop and are especially suited for investigations in sensitive areas such as Rock Art sites. Moisture movement has been mapped and related to the weathering processes observed on the surface. The aim of the study is to aid Rock Art conservation in the Golden Gate Reserve through a better understanding of the driving processes of surface weathering. The evidence shows that the extensive flaking and honeycombing found in the rock shelters is most likely caused by water pockets in the near-surface zone, which are replenished through internal moisture transport, driving the superficial weathering processes. These weathering processes pose a significant problem: Rock Art in the Golden Gate Reserve shows severe deterioration due to flaking. Conservation strategies should therefore take internal processes into account as much as their superficial expression.

  16. Subcritical crack growth and mechanical weathering: a new consideration of how moisture influences rock erosion rates.

    NASA Astrophysics Data System (ADS)

    Eppes, Martha-Cary; Keanini, Russell; Hancock, Gregory S.

    2016-04-01

    The contributions of moisture to the mechanical aspects of rock weathering and regolith production are poorly quantified. In particular, geomorphologists have largely overlooked the role of subcritical crack growth processes in physical weathering and the fact that moisture strongly influences the rates of those processes. This influence is irrespective of the function that moisture plays in stress loading mechanisms like freezing or hydration. Here we present a simple numerical model that explores the efficacy of subcritical crack growth in granite rock subaerially exposed under a range of moisture conditions. Because most weathering-related stress loading for rocks found at, or near, Earth's surface (hereafter surface rocks) is cyclic, we modeled crack growth using a novel combination of Paris' Law and Charles' Law. This combination allowed us to apply existing empirically-derived data for the stress corrosion index of Charles' Law to fatigue cracking. For stress, we focused on the relatively straightforward case of intergranular stresses that arise during solar-induced thermal cycling by conductive heat transfer, making the assumption that such stresses represent a universal minimum weathering stress experienced by all surface rocks. Because all other tensile weathering-related stresses would be additive in the context of crack growth, however, our model can be adapted to include other stress loading mechanisms. We validated our calculations using recently published thermal-stress-induced cracking rates. Our results demonstrate that 1) weathering-induced stresses as modeled herein, and as published by others, are sufficient to propagate fractures subcritically over long timescales with or without the presence of water 2) fracture propagation rates increase exponentially with respect to moisture, specifically relative humidity 3) fracture propagation rates driven by thermal cycling are strongly dependent on the magnitude of diurnal temperature ranges and the

  17. The interactions of compressive stress and weathering in driving rock fracture.

    NASA Astrophysics Data System (ADS)

    de Vilder, Saskia; Brain, Matthew; Rosser, Nick; Vann Jones, Emma

    2016-04-01

    Weathering plays an important role in weakening a rock mass before failure. The stresses generated by failure triggering events are often an order of magnitude smaller than those required to fracture rock. The compressive stresses of the slope resulting from gravitational load are also in themselves insufficient to result in fracture. Therefore, the rock must have been weakened prior to failure. Recent studies have shown that local stress concentrations within a slope can determine the effectiveness of weathering events. Currently however, the exact impact of this is not well constrained with few studies undertaken to analyse rock weathering under stress. To address this, we report the results of a laboratory testing programme designed to assess the influence of compressive stress on the effectiveness of weathering, specifically saltwater wetting and drying. In these laboratory tests, rock cores were placed under a constant 2 MPa uniaxial compressive stress, corresponding to the approximate compressive stresses at the base of a 60 m high, near-vertical rock slope. The cores consist of moderately strong grey Staithes Siltstone (unconfined compressive stress, UCS, range of 20 - 30 MPa), found along the North Yorkshire coastline, United Kingdom. The samples were subjected to saltwater wetting and drying cycles of 6 hours, designed to mimic the submersion of a coastal cliff by the tide. Modified oedometers were used to place the samples under stress as wetting and drying occurred. We tested 4 samples which had been 'preloaded' in unconfined compression to 13.5 MPa (i.e. exceeding the crack initiation threshold but insufficient to cause fracture) to simulate the role of accumulated damage (i.e. creating a population of microcracks) in the rock slope, along with 4 samples which were not 'preloaded', and 8 samples with varying geometries to simulate the role of cliff-face topography in concentrating stress. Each test had a corresponding control sample which was not placed

  18. Field and laboratory tests on risk of slope failure due to weathering of rock materials

    NASA Astrophysics Data System (ADS)

    Qureshi, M. U.; Towhata, I.; Yamada, S.; Aziz, M.

    2009-04-01

    Authors set out the challenge to explore the mechanism of rock weathering and its effects to the geotechnical hazards. Any natural or human induced disturbances to the natural slopes speed up their weathering process. So, exploration of both disturbed and undisturbed slopes is necessary for robust understanding. Various regions in Asia were explored to experience variety of environmental and climatic conditions. Field exploration on the thickness and in-situ mechanical property was carried out by performing seismic refraction surveys, dynamic cone penetration tests and Schmidt hammer tests at various sites in Japan and Pakistan. In laboratory change in mechanical property of soft rocks due to weathering has been observed and slake durability tests were conducted on various rocks. Field exploration indicated that the thickness of weathered layer is 1 meter or its roundabouts and having S-wave velocity of 200-300 m/s. Laboratory testing differentiated the slaking potential and mechanical property degradation of various rocks. Moreover sensible correlations had been observed in thickness calculated by seismic refraction or dynamic cone penetration in field. Slake durability index showed good correlation with Schmidt hammer hardness and mechanical property. A general agreement was also observed when strength and S-wave velocities from laboratory tests were compared with the field exploration. Authors believed that the study provides the useful information on the long term prediction and assessment of landslide risk.

  19. Short Communication: Evidence for non-Gaussian distribution of rock weathering rates

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.

    2015-09-01

    The weathering of rocks influences the geochemistry of the oceans, the erosion of landscapes and man-made structures, and even the global climate. Although a high degree of variance is often observed in rate measurements, little is understood about the statistical characteristics of weathering rate distributions. This preliminary study demonstrates that the weathering rates of limestone, determined from measurements of an ancient eroded limestone edifice, can exhibit highly non-Gaussian behavior. While a Gaussian model produced a poor fit with the data, an alternative model - the generalized extreme value (GEV) framework - was capable of capturing the asymmetric long-tailed distribution, in good agreement with the measured curve. Furthermore, the non-Gaussian distribution of these field rates was found to have similar characteristics to the distribution of rates measured over much smaller microscopic regions of limestone surfaces in laboratory experiments. Such similar behavior could be indicative of analogous chemical and mechanical weathering processes acting over a range of spatial and temporal scales. Moreover, highly asymmetric rate distributions with high variance could be characteristic of rates not only in carbonate rocks, but also in other rock types, suggesting that the use of a small number of measurements to determine field weathering rates may be insufficient to fully characterize the range of rates in natural systems.

  20. Acid rock drainage and rock weathering in Antarctica: important sources for iron cycling in the Southern Ocean.

    PubMed

    Dold, B; Gonzalez-Toril, E; Aguilera, A; Lopez-Pamo, E; Cisternas, M E; Bucchi, F; Amils, R

    2013-06-18

    Here we describe biogeochemical processes that lead to the generation of acid rock drainage (ARD) and rock weathering on the Antarctic landmass and describe why they are important sources of iron into the Antarctic Ocean. During three expeditions, 2009-2011, we examined three sites on the South Shetland Islands in Antarctica. Two of them displayed intensive sulfide mineralization and generated acidic (pH 3.2-4.5), iron-rich drainage waters (up to 1.78 mM Fe), which infiltrated as groundwater (as Fe(2+)) and as superficial runoff (as Fe(3+)) into the sea, the latter with the formation of schwertmannite in the sea-ice. The formation of ARD in the Antarctic was catalyzed by acid mine drainage microorganisms found in cold climates, including Acidithiobacillus ferrivorans and Thiobacillus plumbophilus. The dissolved iron (DFe) flux from rock weathering (nonmineralized control site) was calculated to be 0.45 × 10(9) g DFe yr(-1) for the nowadays 5468 km of ice-free Antarctic rock coastline which is of the same order of magnitude as glacial or aeolian input to the Southern Ocean. Additionally, the two ARD sites alone liberate 0.026 and 0.057 × 10(9) g DFe yr(-1) as point sources to the sea. The increased iron input correlates with increased phytoplankton production close to the source. This might even be enhanced in the future by a global warming scenario, and could be a process counterbalancing global warming. PMID:23682976

  1. Effects of Space Weathering on Lunar Rocks: Scanning Electron Microscope Petrography

    NASA Technical Reports Server (NTRS)

    Wentworth, Susan J.; Keller, Lindsay P.; McKay, David S.

    1998-01-01

    Lunar rocks that have undergone direct exposure to the space weathering environment at the surface of the Moon commonly have patinas on their surfaces. Patinas are characterized by visible darkening and other changes in spectral properties of rocks. They form as a result of bombardment by micrometeorites, solar wind, and solar flares. Processes of space weathering and patina production have clearly been significant in the formation and history of the lunar regolith. It is very likely that other planetary bodies without atmospheres have undergone similar alteration processes; therefore, it is critical to determine the relationship between patinas and their host rocks in view of future robotic and remote-sensing missions to the Moon and other planetary bodies.

  2. Weathering of basaltic rocks under cold, arid conditions - Antarctica and Mars

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Conca, J.-L.

    1991-01-01

    The processes taking part in the chemical weathering of nonvesicular dolerite cobbles producing etch pits and secondary minerals including clays, under cold arid conditions of high-altitude ice-free areas of Victoria Land (Antarctica) are investigated as a possible analog to processes that produced the pitted rocks and clay minerals on Mars. Results suggest that the pits in the dolerite cobbles are formed by the dissolution of the rock by rare snow-melt water during the austral summer, followed by wind erosion of weathered material. The upper interior walls of the pits are lined with a yellow precipitate consisting of illite and quartz mixture, while the pit bottoms contain alteration products including Fe-rich clay minerals and soluble salts. A model is proposed for rock pitting on Mars analogous to that of the Antarctic dolerites.

  3. In-Situ and Experimental Evidence for Acidic Weathering of Rocks and Soils on Mars

    NASA Technical Reports Server (NTRS)

    Hurowitz, J. A.; McLennan, S. M.; Tosca, N. J.; Arvidson, R. E.; Michalski, J. R.; Ming, D.; Schroeder, C.; Squyres, S. W.

    2006-01-01

    Experimental data for alteration of synthetic Martian basalts at pH=0-1 indicate that chemical fractionations at low pH are vastly different from those observed during terrestrial weathering. Rock analyses from Gusev crater are well described by the relationships apparent from low pH experimental alteration data. A model for rock surface alteration is developed which indicates that a leached alteration zone is present on rock surfaces at Gusev. This zone is not chemically fractionated to a large degree from the underlying rock interior, indicating that the rock surface alteration process has occurred at low fluid-to-rock ratio. The geochemistry of natural rock surfaces analyzed by APXS is consistent with a mixture between adhering soil/dust and the leached alteration zone. The chemistry of rock surfaces analyzed after brushing with the RAT is largely representative of the leached alteration zone. The chemistry of rock surfaces analyzed after grinding with the RAT is largely representative of the interior of the rock, relatively unaffected by the alteration process occurring at the rock surface. Elemental measurements from the Spirit, Opportunity, Pathfinder and Viking 1 landing sites indicate that soil chemistry from widely separated locations is consistent with the low-pH, low fluid to rock ratio alteration relationships developed for Gusev rocks. Soils are affected principally by mobility of FeO and MgO, consistent with alteration of olivine-bearing basalt and subsequent precipitation of FeO and MgO bearing secondary minerals as the primary control on soil geochemistry.

  4. Permeability and microstructural changes due to weathering of pyroclastic rocks in Cappadocia, central Turkey

    NASA Astrophysics Data System (ADS)

    Sato, M.; Takahashi, M.; Anma, R.; Shiomi, K.

    2014-12-01

    Studies of permeability changes of rocks during weathering are important to understand the processes of geomorphological development and how they are influenced by cyclic climatic conditions. Especially volcanic tuffs and pyroclastic flow deposits are easily affected by water absorption and freezing-thawing cycle (Erguler. 2009, Çelik and Ergül 2014). Peculiar erosional landscapes of Cappadocia, central Turkey, with numerous underground cities and carved churches, that made this area a world heritage site, are consists of volcanic tuffs and pyroclastic flow deposits. Understanding permeability changes of such rocks under different conditions are thus important not only to understand fundamental processes of weathering, but also to protect the landscapes of the world heritage sites and archaeological remains. In this study, we aim to evaluate internal void structures and bulk permeability of intact and weathered pyroclastic rocks from Cappadocia using X-ray CT, mercury intrusion porosimetry data and permeability measurement method of flow pump test. Samples of pyroclastic deposits that comprise the landscapes of Rose Valley and Ihlara Valley, were collected from the corresponding strata outside of the preservation areas. Porosity and pore-size distribution for the same samples measured by mercury intrusion porosimetry, indicate that the intact samples have lower porosity than weathered samples and pore sizes were dominantly 1-10μm in calculated radii, whereas weathered samples have more micropores (smaller than 1 μm). X-ray CT images were acquired to observe internal structure of samples. Micro-fractures, probably caused by repeated expansion and contraction due to temperature changes, were observed around clast grains. The higher micropore ratio in weathered samples could be attributed to the development of the micro-farctures. We will discuss fundamental processes of weathering and geomorphological development models using these data.

  5. Rock weathering by indigenous heterotrophic bacteria of Bacillus spp. at different temperature: a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Štyriaková, I.; Štyriak, I.; Oberhänsli, H.

    2012-07-01

    The bio-weathering of basalt, granite and gneiss was experimentally investigated in this study. These rock-forming minerals weathered more rapidly via the ubiquitous psychrotrophic heterotrophic bacteria . With indigenous bacteria of Bacillus spp. from sediments of Lake Baikal, we traced the degradation process of silicate minerals to understand the weathering processes occurring at the change temperature in the subsurface environment with organic input. The bacteria mediated dissolution of minerals was monitored with solution and solid chemistry, X-ray analyses as well as microscopic techniques. We determined the impact of the bacteria on the mineral surface and leaching of K, Ca, Mg, Si, Fe, and Al from silicate minerals. In the samples the release of major structural elements of silicates was used as an overall indicator of silicate mineral degradation at 4°C and 18°C from five medium exchanges over 255 days of rock bioleaching. The increase of temperature importantly affected the efficiency of Fe extraction from granite and basalt as well as Si extraction from granite and gneiss. In comparison with elemental extraction order at 4°C, Ca was substituted first by Fe or Si. It is evident that temperature influences rock microbial weathering and results in a change of elements extraction.

  6. Real-time Observations of Rock Cracking and Weather Provide Insights into Thermal Stress-Related Processes of Mechanical Weathering.

    NASA Astrophysics Data System (ADS)

    Eppes, M. C.; Magi, B. I.; Keanini, R.

    2015-12-01

    The environmental conditions (weather and/or climate) that limit or drive mechanical weathering via thermal stress are poorly understood. Here we examine acoustic emission (AE) records of rock cracking in boulders sitting on the ground in humid-temperate (~1 year of data) and semi-arid (~3 years) locations. We compare on-site average ambient daily temperature for days in which cracking occurs to the average temperatures for those dates derived from local climate records. The temperatures characterizing days on which cracking occurs is similar for both stations (range = -10 C to +30 C); where 21% and 73% of cracking occurs on hot days (> 20C) in the humid and semi-arid climates respectively while 17% and 0.1% occurs on very cold days (-8C to -3C). When days during which cracking occurs are compared to climate averages, 81% (NC) and 51% (NM) of all cracking occurs on days with absolute temperature anomalies >1, regardless of the temperature. The proportion of cracking that occurs on anomalously hot or cold days rises to 92% and 77% when the data is normalized to account for uneven sampling of the days with extreme temperatures. In order to determine to what extent this trend holds true in a more complex setting, we examined an existing 100+ year record of rock falls from Yosemite Valley. Preliminary results, although more equivocal, are consistent with the boulder cracking AE data. We examine the AE datasets in the context of our previous numerical modeling of insolation-driven thermal stress in rock and hypothesize that there is an increased potential for fracture on days with extreme temperatures because 1) thermal-stress is dependent on temperature variance from far-field and/or average rock temperatures and 2) that days with climatologically extreme air temperatures result in maximums in such variance. An implication of our results is that environments with extreme weather variability may have higher thermal breakdown rates, including certain locations today and

  7. Excavatability and the effect of weathering degree on the excavatability of rock masses: An example from Eastern Turkey

    NASA Astrophysics Data System (ADS)

    Gurocak, Zulfu; Yalcin, Erkut

    2016-06-01

    In this study, the effect of the weathering degree on the excavatability of rock masses was investigated. The ophiolitic rock mass along the route of Komurhan Tunnel was chosen as the case study. Both laboratory and field studies were carried out for this purpose. In the first stage, the ophiolitic rock mass along the tunnel route was classified into three subzones according to the weathering degree and the ophiolitic rock masses of the each subzones were classified using the empirical excavatability classifications proposed by the different researchers. Furthermore, in-situ excavatability classes of rock masses in each zone were determined and the results were compared. The in-situ excavatability class of fresh (Zone-I) and slightly weathered (Zone-II) rock masses was determined as Blasting and that of moderately weathered (Zone-III) rock mass was determined as Very Hard/Very Difficult. As the obtained results were compared, it was found that the weathering degree has a significant effect on the excavatability and that it is more appropriate to prefer empirical classifications in the empirical determination of excavatability classes of rock masses having the same lithology by taking the weathering degree into account.

  8. Behaviour of chemical elements during weathering of pyroclastic rocks, Hong Kong.

    PubMed

    Malpas, J; Duzgoren-Aydin, N S; Aydin, A

    2001-05-01

    The behaviour of whole-rock major, trace and rare earth elements (REE) during weathering under subtropical conditions is examined along a profile developed over crystal--vitric tuffs with eutaxitic texture. The intensity of weathering within the profile varies erratically, indicating weathering processes operate over different scales. Quartz, K-feldspar, plagioclase and biotite are the main primary minerals, whereas clays, sesquioxides, sericite and chlorite are the alteration products. Kaolinite, halloysite and illite-mica are the dominant clay minerals present in significantly varying proportions. Two competing processes, namely leaching and fixation, are the main regulators of variations in mostly major and some trace element concentrations along the profile. In general, as the intensity of weathering increases, Ca, Na, K, Sr +/- Si decrease, while Fe, Ti, Al and loss of ignition (LOI) increase. Likewise, the intensity of negative Eu-anomaly decreases while the intensity of negative Ce-anomaly and the La/Lu and Sm/Nd ratios increases. In detail, however, the behaviour of chemical elements cannot be solely explained in terms of the degree of weathering. This study makes it clearly evident that the type and abundance of sesquioxides and clay minerals can significantly modify the geochemical signatures of weathering processes. PMID:11392752

  9. Weathering products of basic rocks as sorptive materials of natural radionuclides

    SciTech Connect

    Omelianenko, B.I.; Niconov, B.S.; Ryzhov, B.I.; Shikina, N.D.

    1994-06-01

    The principal requirements for employing natural minerals as buffer and backfill material in high-level waste (HLW) repositories are high sorptive properties, low water permeability, relatively high thermal conductivity, and thermostability. The major task of the buffer is to prevent the penetration of radionuclides into groundwater. The authors of this report examined weathered basic rocks from three regions of Russia in consideration as a suitable radioactive waste barrier.

  10. A modelling study on the fractionation of uranium among minerals during rock weathering

    SciTech Connect

    Ohnuki, Toshihiko; Murakami, Takashi; Yanase, Nobuyuki

    1993-12-31

    A modelling study has been carried out to understand the effect of rock alteration on the fractionation of uranium among coexisting minerals (chlorite, vermiculite, kaolinite, amorphous and crystalline iron minerals) at the Koongarra ore deposit, Australia. The model considers the chlorite weathering process, its mechanism and rate, and assumes the presence of reversible and irreversible sorption sites in the secondary minerals. The calculated uranium concentrations at the two different sites in the minerals were compared with the results of sequential extraction experiments. Good agreement between the calculated and observed uranium concentrations was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of the altered clay minerals. However, a conventional K{sub d} model gave inconsistent uranium concentrations. The calculated results show that the crystalline iron minerals sorb uranium during all stages of weathering, and that the uranium fractionation among the minerals varies with time until the end of the weathering.

  11. A landscape in three biospheres: biological rock weathering in a model ecosystem

    NASA Astrophysics Data System (ADS)

    Presler, J. K.

    2012-12-01

    Biological rock weathering is the process by which life breaks down minerals into forms that are readily available for creation of an ecosystem. In order to test how microbes, plants and mycorrhizal communities interact with bedrock to initiate a primary ecosystem that will eventually lead to soil formation, we developed a modular experiment in the desert biome of Biosphere-2. In this presentation we present selected phases in the development of the experimental setup. Briefly, we aimed to replicate a large-scale primordial landscape in a closed, mesocosm system involving six carefully designed, identical chambers, each containing 48 experimental columns, 30cm long. The rocks used, i.e. basalt, rhyolite, granite and schist, represent four prevalent rock types in the natural landscape. The biotic communities are represented by combinations of rock microbial communities, plants and their associated mycorrhizae. Bacterial inoculum was optimized for each rock type. Each model was created to remain completely separated from outside influence. We expect that this experiment will provide crucial knowledge about primary interactions between rock and biota on Earth. Experimental Modules

  12. Weathering in interbedded marls and conglomerates - the 1806 Goldau rock slide

    NASA Astrophysics Data System (ADS)

    Thuro, K.; Eberhard, E.

    2003-04-01

    Despite improvements in recognition, prediction and mitigation, landslides still exact a heavy social, economical and environmental toll in Switzerland. Recent landslides experienced in the Swiss Alps demonstrate the need for a deeper understanding of the geological and physical processes leading to catastrophic slope failure. Large-scale rockslides (e.g. Randa, Sandalp, Goldau, Elm, etc.), illustrate the destructive potential of these mass movements and the need for further study to improve our comprehension of the mechanisms involved. Advances in rockslide hazard assessment and forecasting will only be made when the mechanisms responsible for the evolution of catastrophic failures are better understood. To date, the study of mass movements (including rockslides) has been largely descriptive and qualitative. Studies that do focus on some quantitative aspect of large-scale mass movements are often limited to individual mechanisms or triggering processes. Traditional treatments have pursued phenomenological based approaches where a two-dimensional slide plane is assumed or delineated from survey or air photo data, and a back analysis is performed to determine the conditions existing on the surface at failure. In other words, rock slope stability analyses have largely focused on the back-analysis of a static picture of the problem, without considering how the development of the instability evolved with time. In this paper, we aim to emphasize on the evolutionary failure processes leading to large-scale mass movements in adversely dipping bedded marls and conglomerates. Of key importance are the weathering characteristics of the marl and which tend to rapidly degrade when exposed to weathering processes. The proposed hypothesis contends that rock slope instability, in such geological environments, occurs through 3 primary processes: (1) weathering of the marls including increases in pore volume (promoting water seepage), decalcification and intact strength degradation

  13. Characterization of weathering profile in granites and volcanosedimentary rocks in West Africa under humid tropical climate conditions. Case of the Dimbokro Catchment (Ivory Coast)

    NASA Astrophysics Data System (ADS)

    Koita, M.; Jourde, H.; Koffi, K. J. P.; da Silveira, K. S.; Biaou, A.

    2013-06-01

    In granitic rocks, various models of weathering profile have been proposed, but never for the hard rocks of West Africa. Besides, in the literature there is no description of the weathering profile in volcanosedimentrary rocks. Therefore, we propose three models describing the weathering profiles in granites, metasediments, and volcanic rocks for hard rock formations located in West Africa. For each of these models proposed for granitic and volcanosedimentary rocks of the Dimbokro catchment, vertical layered weathering profiles are described, according to the various weathering and erosion cycles (specific to West Africa) that the geological formations of the Dimbokro catchment experienced from the Eocene to the recent Quaternary period. The characterization of weathering profiles is based on: i) bedrocks and weathering profile observations at outcrop, and ii) interpretation and synthesis of geophysical data and lithologs from different boreholes. For each of the geological formations (granites, metasediments, and volcanic rocks), their related weathering profile model depicted from top to bottom comprises four separate layers: alloterite, isalterite, fissured layer, and fractured fresh basement. These weathering profiles are systematically covered by a soil layer. Though granites, metasediments and volcanic rocks of the Dimbokro catchment experience the same weathering and erosion cycles during the palaeoclimatic fluctuations from Eocene to recent Quaternary period, they exhibit differences in thickness. In granites, the weathering profile is relatively thin due to the absence of iron crust which protects weathering products against dismantling. In metasediments and volcanic rocks iron crusts develop better than in granites; in these rocks the alterite are more resistant to dismantling.

  14. Rock-moisture dynamics in a hillsope underlain with weathered and fractured argillite

    NASA Astrophysics Data System (ADS)

    Salve, R.; Rempe, D. M.; Dietrich, W.

    2012-12-01

    In order to explore the recharge process through a deep, weathered bedrock zone in a strongly seasonal rainfall environment, we document the early rainy season and annual rock-moisture dynamics along a steep Northern California hillslope underlain by a thick zone of unsaturated weathered and fractured argillite. All runoff to the channel at the base of the hillslope occurs via groundwater flow that is perched on underlying low-permeability fresh bedrock. We report the timing and depth of the first rise in moisture content in response to early winter rains and storm, seasonal, and annual moisture dynamics throughout the zone. Our measurements show that after a long summer dry season, the first rains rapidly penetrate through the soil mantle and into the underlying weathered bedrock. Large rains generate a response as deep as 6 m into the weathered bedrock within a few weeks. But within hours to days of the start of rain, the perched groundwater, at depths from 4 to 18 m below the surface, responds. The wetting advanced into the bedrock, with the groundwater response magnitude and timing differing greatly across the hillslope. We distinguish soil moisture from rock moisture (which includes both exchangeable matrix water and fracture water) and find that while the soil moisture dynamically rises and falls with each successive storm event, the rock moisture in the shallow, weathered bedrock tends to vary less after initial wet up. Surprisingly, despite the more than 1400 mm of annual water flux through the unsaturated zone, the lower portions near the water table show no moisture variation, even as the water table rises and falls with each storm pulse. These observations suggest that fracture flow plays a predominant role in transmitting water to the water table, and hence, the runoff characteristics, water chemistry, rock-moisture availability to vegetation, the hillslope stability itself is tied to this process. We present a conceptual model to explain these dynamics

  15. Life on rock. Scaling down biological weathering in a new experimental design at Biosphere-2

    NASA Astrophysics Data System (ADS)

    Zaharescu, D. G.; Dontsova, K.; Burghelea, C. I.; Chorover, J.; Maier, R.; Perdrial, J. N.

    2012-12-01

    Biological colonization and weathering of bedrock on Earth is a major driver of landscape and ecosystem development, its effects reaching out into other major systems such climate and geochemical cycles of elements. In order to understand how microbe-plant-mycorrhizae communities interact with bedrock in the first phases of mineral weathering we developed a novel experimental design in the Desert Biome at Biosphere-2, University of Arizona (U.S.A). This presentation will focus on the development of the experimental setup. Briefly, six enclosed modules were designed to hold 288 experimental columns that will accommodate 4 rock types and 6 biological treatments. Each module is developed on 3 levels. A lower volume, able to withstand the weight of both, rock material and the rest of the structure, accommodates the sampling elements. A middle volume, houses the experimental columns in a dark chamber. A clear, upper section forms the habitat exposed to sunlight. This volume is completely sealed form exterior and it allows a complete control of its air and water parameters. All modules are connected in parallel with a double air purification system that delivers a permanent air flow. This setup is expected to provide a model experiment, able to test important processes in the interaction rock-life at grain-to- molecular scale.

  16. Lead isotopes tracing the life cycle of a catchment: From source rock via weathering to human impact

    NASA Astrophysics Data System (ADS)

    Negrel, P. J.; Petelet-Giraud, E.; Guerrot, C.; Millot, R.

    2015-12-01

    Chemical weathering of rocks involves consumption of CO2, a greenhouse gas with a strong influence on climate. Among rocks exposed to weathering, basalt plays a major role in the carbon cycle as it is more easily weathered than other crystalline silicate rocks. This means that basalt weathering acts as a major atmospheric CO2 sink. The present study investigated the lead isotopes in rock, soil and sediment for constraining the life cycle of a catchment, covering source rocks, erosion processes and products, and anthropogenic activities. For this, we investigated the Allanche river drainage basin in the Massif Central, the largest volcanic areas in France, that offers opportunities for selected geochemical studies since it drains a single type of virtually unpolluted volcanic rock, with agricultural activity increasing downstream. Soil and sediment are derived exclusively from basalt weathering, and their chemistry, coupled to isotope tracing, should shed light on the behavior of chemical species during weathering from parental bedrock. Bedrock samples of the basin, compared to regional bedrock of the volcanic province, resulted from a complex history and multiple mantle reservoir sources and mixing. Regarding soils and sediments, comparison of Pb and Zr normalized to mobile K shows a linear evolution of weathering processes, whereby lead enrichment from atmospheric deposition is the other major contributor. Lead-isotope ratios showed that most of the lead budget in sediment and soil results from bedrock weathering with an influence of past mining and mineral processing of ores in the Massif Central, and deposition of lead-rich particles from gasoline combustion, but no lead input from agricultural activity. A classic box model was used to investigate the dynamics of sediment transfer at the catchment scale, the lead behavior in the continuum bedrock-soil-sediment and the historical evolution of anthropogenic aerosol emissions.

  17. Neutron Activation Analysis for the Demonstration of Amphibolite Rock-Weathering Activity of a Yeast

    PubMed Central

    Rades-Rohkohl, E.; Hirsch, P.; Fränzle, O.

    1979-01-01

    Neutron activation analysis was employed in a survey of weathering abilities of rock surface microorganisms. A yeast isolated from an amphibolite of a megalithic grave was found actively to concentrate, in media and in or on cells, iron and other elements when grown in the presence of ground rock. This was demonstrated by comparing a spectrum of neutron-activated amphibolite powder (particle size, 50 to 100 μm) with the spectra of neutron-activated, lyophilized yeast cells which had grown with or without amphibolite powder added to different media. The most active yeast (IFAM 1171) did not only solubilize Fe from the rock powder, but significant amounts of Co, Eu, Yb, Ca, Ba, Sc, Lu, Cr, Th, and U were also mobilized. The latter two elements occurred as natural radioactive isotopes in this amphibolite. When the yeast cells were grown with neutron-activated amphibolite, the cells contained the same elements. Furthermore, the growth medium contained Fe, Co, and Eu which had been solubilized from the amphibolite. This indicates the presence, in this yeast strain, of active rockweathering abilities as well as of uptake mechanisms for solubilized rock components. PMID:16345472

  18. The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.

    PubMed

    Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

    2015-09-01

    On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification. PMID:25211602

  19. Visible and infrared properties of unaltered to weathered rocks from Precambrian granite-greenstone terrains of the West African Craton

    NASA Astrophysics Data System (ADS)

    Metelka, Václav; Baratoux, Lenka; Jessell, Mark W.; Naba, Séta

    2015-12-01

    In situ and laboratory 0.35 μm-2.5 μm spectra of rocks from a Paleoproterozoic granite-greenstone terrain along with its Neoproterozoic sedimentary cover and derived regolith materials were examined in western Burkina Faso. The reflectance spectra show the influence of typical arid to semi-arid weathering with the formation of desert varnish, iron films, and dust coatings. Fe and Mg-OH absorption features related to chlorite, amphibole, pyroxene, epidote, and biotite are observable in the mafic and intermediate meta-volcanic rocks as well as in the granodiorites and tonalites. Al-OH absorption caused by kaolinite, smectite, illite/muscovite are typical for meta-volcano-sedimentary schists, Tarkwaian-type detrital meta-sediments, sandstones of the Taoudeni basin, all of the weathered surfaces and regolith materials. Ferric and ferrous iron absorptions related to both primary rock-forming minerals and secondary weathering minerals (goethite, hematite) were observed in most of the sampled materials. The results show that although weathering alters the spectral signature of the fresh rock, indicative absorption features located in the short wave infrared region remain detectable. In addition, spectra of soils partially reflect the mineral composition of the weathered rock surfaces. The analysis of the hyperspectral data shows the potential of differentiating between the sampled surfaces. The library presents a primary database for the geological and regolith analysis of remote sensing data in West Africa.

  20. Chemical weathering of granitic rock: experiments and Pb-Li isotopes tracing

    NASA Astrophysics Data System (ADS)

    Millot, R.; Négrel, P.

    2011-12-01

    In a recent study (Négrel et al. 2010, Chem. Geol. Vol. 274) focusing on the lead geochemistry and Pb-isotope ratios of groundwaters along a small (53 km2) endoreic granitic catchment in India (Masheshwaram, Andhra Pradesh), we have shown that most of the lead in the groundwaters is of geogenic origin. Combining a weathering model and field observations, we were able to define a two-step weathering process that includes a control on the Pb-isotope ratios by accessory phases and by the main minerals from the granite in a second step of weathering. In order to go further and to better characterize water/rock interactions, we performed laboratory experiments with the two main granite bedrocks from this site. The aim of the present work is to better constrain the processes of water/rock interactions both in terms of source (dissolution of different primary minerals) and extent of weathering, by measuring Pb isotope signatures in addition with Li isotope signatures. Laboratory experiments consisted in measuring the evolution through time of major and trace elements, as well as Pb and Li isotopic compositions of a rainwater solution in equilibrium with a granite powder. Experiments were carried out at 25°C with a solution/powder mass ratio of 10 considering 15 mL of reference solution TMRAIN-95 and 1.5 g of powdered granite placed in screw-top Teflon° PFA beakers. The beakers were kept in a temperature-controlled oven, which temperature was maintained within 5% of target temperature over the total duration of the experiments. Aliquots of the solution (after filtration at 0.2 μm) in contact with the granite powder were periodically sampled (from weeks up to 2 years) and analyzed for lead and lithium isotopic compositions. The results show that a radiogenic contribution of lead is observed during the experiments, in agreement with the field observations, and that the light lithium isotope (6Li) is preferentially retained during uptake of Li into secondary minerals. The

  1. Rock Abrasion as Seen by the MSL Curiosity Rover: Insights on Physical Weathering on Mars

    NASA Astrophysics Data System (ADS)

    Bridges, N.; Day, M. D.; Le Mouelic, S.; Martin-Torres, F. J.; Newsom, H. E.; Sullivan, R. J., Jr.; Ullan, A.; Wiens, R. C.; Zorzano, M. P.

    2014-12-01

    Mars is a dry planet, with actively blowing sand in many regions. In the absence of stable liquid water and an active hydrosphere, rates of chemical weathering are slow, such that aeolian abrasion is a dominant agent of landscape modification where sand is present and winds above threshold occur at sufficient frequency. Reflecting this activity, ventifacts, rocks that have been abraded by windborne particles, and wind-eroded outcrops, are common. They provide invaluable markers of the Martian wind record and insight into climate and landscape modification. Ventifacts are distributed along the traverse of the Mars Science Laboratory Curiosity rover. They contain one or more diagnostic features and textures: Facets, keels, basal sills, elongated pits, scallops/flutes, grooves, rock tails, and lineations. Keels at the junction of facets are sharp enough to pose a hazard MSL's wheels in some areas. Geomorphic and textural patterns on outcrops indicate retreat of windward faces. Moonlight Valley and other depressions are demarcated by undercut walls and scree boulders, with the valley interiors containing fewer rocks, most of which show evidence for significant abrasion. Together, this suggests widening and undercutting of the valley walls, and erosion of interior rocks, by windblown sand. HiRISE images do not show any dark sand dunes in the traverse so far, in contrast to the large dune field to the south that is migrating up to 2 m per year. In addition, ChemCam shows that the rock Bathurst has a rind rich in mobile elements that would be removed in an abrading environment. This indicates that rock abrasion was likely more dominant in the past, a hypothesis consistent with rapid scarp retreat as suggested by the cosmogenic noble gases in Yellowknife Bay. Ventifacts and evidence for bedrock abrasion have also been found at the Pathfinder, Spirit, and Opportunity sites, areas, like the Curiosity traverse so far, that lack evidence for current high sand fluxes. Yardangs

  2. Effects of direct and indirect heating on the validity of rock weathering simulation studies and durability tests

    NASA Astrophysics Data System (ADS)

    Warke, P. A.; Smith, B. J.

    1998-04-01

    Rock surface and subsurface temperature responses in samples exposed to direct heating (insolation) under natural hot desert conditions reveal considerable variability between lithologies related to differences in thermal properties, especially albedo and thermal conductivity. However, when the same samples are heated indirectly by air in an oven-based environmental cabinet, lithological differences in temperature response disappear and all samples attain temperatures similar to the air temperature within the cabinet. Rates and patterns of rock decay produced in such environmental cabinets may not, therefore, reflect those encountered under natural conditions, where breakdown is related to micro-environmental conditions at the rock/air interface and where rock temperature is one of the most important controlling factors. In addition to implications for assessment of weathering effectiveness, use of only indirect forms of heating affects the determination of comparative rock durability because all rock types are cycled through the same temperature regimes. Because temperature exerts such a major control on rock breakdown through its control on physical and chemical weathering processes, all significant factors influencing it must be included in the design of weathering simulations and durability tests.

  3. Evidence for Physical Weathering of Iron Meteorite Meridiani Planum (Heat Shield Rock) on Mars

    NASA Astrophysics Data System (ADS)

    Ashley, J. W.; McCoy, T. J.; Schröder, C.

    2009-12-01

    Meteorites on the surfaces of other solar system bodies can provide natural experiments for monitoring weathering processes. In the case of Mars, clues to the more subtle aspects of water occurrence and reaction may be revealed by the effects of highly sensitive aqueous alteration processes, while physical processes may be recorded through aeolian abrasion effects. Over the past 2000 sols, the two Mars Exploration Rover (MER) spacecraft have formally identified a minimum of 11 meteorite candidates [1-3], with many more unofficial candidates likely, posing an intriguing set of questions concerning their chemical, mineralogical, and morphological conditions. Five meteorite candidates, including the newly discovered MER-B rock Block Island, and one confirmed meteorite [Meridiani Planum (MP; originally Heat Shield Rock)] [4] have been investigated with the rover arm instruments. All contain levels of ferric iron, which should not be present in pristine samples (i.e. without fusion crust and/or alteration phases). Moreover, preliminary morphologic evidence contributes to the case of possible chemical weathering in Block Island. Scrutiny of a Microscopic Imager (MI) mosaic of MP shows clear evidence for both localized aeolian sculpting, and the Widmanstätten pattern common to sliced and acid-etched surfaces of many iron-nickel meteorites. These latter features are manifest as millimeter-sized chevrons and subparallel linearities, most prominent across a partially brushed surface approximately 3 x 2 cm in area. Similar patterns are observed on a number of hot and cold desert meteorites (e.g. Drum Mountain and Ft. Stockton), and are attributed to physical ablation by sand grains differentially weathering the kamacite and taenite lamellae within the rock. A similar or identical process is interpreted as responsible for the features observed in MP. Other macro-scale features on MP are of questionable weathering origin. While some prefer a regmaglypt interpretation for the

  4. A study of the depth of weathering and its relationship to the mechanical properties of near-surface rocks in the Mojave Desert

    NASA Astrophysics Data System (ADS)

    Stierman, Donald J.; Healy, John H.

    1984-03-01

    Weathered granite extends 70 m deep at Hi Vista in the arid central Mojave Desert of southern California. The low strength of this granite is due to the alteration of biotite and chlorite montmorillonite. Deep weathering probably occurs in most granites, although we cannot rule out some anomalous mechanisms at Hi Vista. Geophysical instruments set in these slightly altered rocks are limited by the unstable behavior of the rocks. Thus, tectonic signals from instruments placed in shallow boreholes give vague results. Geophysical measurements of these weathered rocks resemble measurements of granitic rocks near major faults. The rheology of the rocks in which instruments are placed limits the useful sensitivity of the instruments.

  5. Chemical weathering on Mars - Thermodynamic stabilities of primary minerals /and their alteration products/ from mafic igneous rocks

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1978-01-01

    Chemical weathering on Mars is examined theoretically from the standpoint of thermodynamic equilibrium between primary rock-forming minerals and the atmospheric gases O2, H2O, and CO2. The primary minerals considered are those common to mafic igneous rocks and include olivine, pyroxene, plagioclase, magnetite, troilite, pyrrhotite, and apatite. The importance of kinetics and reaction mechanisms in controlling possible weathering processes on Mars is discussed within the limits of currently available data, and the possible influence of liquid water on Martian weathering processes is evaluated where appropriate. For gas-solid weathering of mafic igneous rocks at the Martian surface, it is concluded that upon attainment of thermodynamic equilibrium: (1) oxides and carbonates should dominate the mineral assemblage of weathering products; (2) hematite rather than goethite should be the stable mineral form of Fe (III); (3) FeSO4 or FeSO4.H2O could be the stable weathering product of iron sulfides in the absence of liquid water; and (4) kaolinite is apparently the only clay mineral that should be thermodynamically stable over all ranges of temperature and water-vapor abundance at the Martian surface.

  6. Terrestrial and stream chemical linkages reveal extent of rock weathering in the perhumid coastal temperate rainforest of Alaska.

    NASA Astrophysics Data System (ADS)

    D'Amore, D. V.; Trainor, T.

    2014-12-01

    Climate influences the rate of reactions that drive material fluxes, especially the rock-water interaction within the earth's critical zone. The perhumid temperate rainforests of southeast Alaska (PCTR) are valuable sites for testing theories and applying models for ecosystem development. The landscape of the PCTR is chronologically young, but by contrast, has experienced rapid change during the Holocene due to a humid climate that promotes intense soil weathering and rapid accumulation of soil organic carbon. We investigated the magnitude of present rock-water interaction in several catchments and watersheds arrayed across a spectrum of this landscape evolution. All of the catchments had evidence of weathering as indicated by cation export relative to sea-salt aerosol input. The magnitude of the weathering signature was inversely related to the accumulation of organic carbon in the catchment. We conclude that biological processes inhibit the weathering of lithologic materials due to organic matter accumulation. However, there is clear evidence that the landscape is still actively weathering. The extent of the consumption of CO2 by rock weathering will be critical in determining long-term carbon budgets in the region and determining the sink strength of the terrestrial ecosystem. This study provides a template for examining landscape evolution in the context of critical zone science in a relatively pristine landscape.

  7. Bacterially Induced Weathering of Ultramafic Rock and Its Implications for Phytoextraction

    PubMed Central

    Kidd, Petra; Kuffner, Melanie; Prieto-Fernández, Ángeles; Hann, Stephan; Monterroso, Carmela; Sessitsch, Angela; Wenzel, Walter; Puschenreiter, Markus

    2013-01-01

    The bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of two Arthrobacter strains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4 solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulator Alyssum serpyllifolium subsp. malacitanum was grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants. PMID:23793627

  8. Controls on Weathering of Pyrrhotite in a Low-Sulfide, Granitic Mine-Waste Rock in the Canadian Arctic

    NASA Astrophysics Data System (ADS)

    Langman, J. B.; Holland, S.; Sinclair, S.; Blowes, D.

    2013-12-01

    Increased environmental risk is incurred with expansion of mineral extraction in the Arctic. A greater understanding of geochemical processes associated with hard-rock mining in this cold climate is needed to evaluate and mitigate these risks. A laboratory and in-situ experiment was conducted to examine mineral weathering and the generation of acid rock drainage in a low-sulfide, run-of-mine waste rock in an Arctic climate. Rock with different concentrations of sulfides (primarily pyrrhotite [Fe7S8] containing small amounts of Co and Ni) and carbonates were weathered in the laboratory and in-situ, large-scale test piles to examine leachate composition and mineral weathering. The relatively larger sulfide-containing rock produced sufficient acid to overcome carbonate buffering and produced a declining pH environment with concomitant release of SO4, Fe, Co, and Ni. Following carbonate consumption, aluminosilicate buffering stabilized the pH above 4 until a reduction in acid generation. Results from the laboratory experiment assisted in determining that after consumption of 1.6 percent of the total sulfide, the larger sulfide-concentration test pile likely is at an internal steady-state or maximal weathering rate after seven years of precipitation input and weathering that is controlled by an annual freeze-thaw cycle. Further weathering of the test pile should be driven by external factors of temperature and precipitation in this Arctic, semi-arid region instead of internal factors of wetting and non-equilibrium buffering. It is predicted that maximal weathering will continue until at least 20 percent of the total sulfide is consumed. Using the identified evolution of sulfide consumption in this Arctic climate, a variable rate factor can now be assessed for the possible early evolution and maximal weathering of larger scale waste-rock piles and seasonal differences because of changes in the volume of a waste-rock pile undergoing active weathering due to the freeze

  9. Excavatability Assessment of Weathered Sedimentary Rock Mass Using Seismic Velocity Method

    SciTech Connect

    Bin Mohamad, Edy Tonnizam; Noor, Muhazian Md; Isa, Mohamed Fauzi Bin Md.; Mazlan, Ain Naadia; Saad, Rosli

    2010-12-23

    Seismic refraction method is one of the most popular methods in assessing surface excavation. The main objective of the seismic data acquisition is to delineate the subsurface into velocity profiles as different velocity can be correlated to identify different materials. The physical principal used for the determination of excavatability is that seismic waves travel faster through denser material as compared to less consolidated material. In general, a lower velocity indicates material that is soft and a higher velocity indicates more difficult to be excavated. However, a few researchers have noted that seismic velocity method alone does not correlate well with the excavatability of the material. In this study, a seismic velocity method was used in Nusajaya, Johor to assess the accuracy of this seismic velocity method with excavatability of the weathered sedimentary rock mass. A direct ripping run by monitoring the actual production of ripping has been employed at later stage and compared to the ripper manufacturer's recommendation. This paper presents the findings of the seismic velocity tests in weathered sedimentary area. The reliability of using this method with the actual rippability trials is also presented.

  10. Geochemistry of Neogene sedimentary rocks from Borneo Basin, Malaysia: implications on paleo-weathering, provenance and tectonic setting

    NASA Astrophysics Data System (ADS)

    Ramasmay, N.; Roy, P.; MP, J.; Rufino, L.; Franz, L. K.; Viswanathan, P. M.

    2013-05-01

    Multi-element geochemistry and mineralogy are used to characterize the chemical composition, degree of paleo-weathering, provenance and tectonic settingsof the Neogene sedimentary rocks of Borneo Basin from east Malaysia. The sedimentary rocks are classified as extremely weathered sandstones (i.e. wacke, arkose, litharenite, Fe-sandstone and quartz arenite). Higher values of both weathering indices of alteration (i.e. CIA>83 and PIA>89) suggest that the sandstones have undergone extreme chemical weathering. Absence of any feldspar in the mineralogical analysis indicates its degradation during the weathering. Except for the quartz arenite, all other sandstones are characterized by post-depositional K-metasomatism and zircon enrichment through sediment recycling. The geochemical characteristics suggest a mixed-nature provenance for the sandstones with contribution coming from both felsic and mafic igneous rocks. Enriched Cr in quartz arenite and Fe-sandstone are related to contribution from ophiolite or fractionation of Cr-bearing minerals. The inferred tectonic settings are variable and suggest a complex nature of tectonic environment in the basin.

  11. Microbial populations and activities in the rhizoplane of rock-weathering desert plants. II. Growth promotion of cactus seedlings.

    PubMed

    Puente, M E; Li, C Y; Bashan, Y

    2004-09-01

    Four bacterial species isolated from the rhizoplane of cacti growing in bare lava rocks were assessed for growth promotion of giant cardon cactus seedlings (Pachycereus pringlei). These bacteria fixed N(2), dissolved P, weathered extrusive igneous rock, marble, and limestone, and significantly mobilized useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn in rock minerals. Cardon cactus seeds inoculated with these bacteria were able to sprout and grow normally without added nutrients for at least 12 months in pulverized extrusive igneous rock (ancient lava flows) mixed with perlite. Cacti that were not inoculated grew less vigorously and some died. The amount of useful minerals (P, K, Fe, Mg) for plant growth extracted from the pulverized lava, measured after cultivation of inoculated plants, was significant. This study shows that rhizoplane bacteria isolated from rock-growing cacti promote growth of a cactus species, and can help supply essential minerals for a prolonged period of time. PMID:15375736

  12. Weather.

    ERIC Educational Resources Information Center

    Web Feet K-8, 2000

    2000-01-01

    This subject guide to weather resources includes Web sites, CD-ROMs and software, videos, books, audios, magazines, and professional resources. Related disciplines are indicated, age levels are specified, and a student activity is included. (LRW)

  13. Integrating topography, hydrology and rock structure in weathering rate models of spring watersheds

    NASA Astrophysics Data System (ADS)

    Pacheco, Fernando A. L.; Van der Weijden, Cornelis H.

    2012-03-01

    SummaryWeathering rate models designed for watersheds combine chemical data of discharging waters with morphologic and hydrologic parameters of the catchments. At the spring watershed scale, evaluation of morphologic parameters is subjective due to difficulties in conceiving the catchment geometry. Besides, when springs emerge from crystalline massifs, rock structure must be accounted in formulas describing the area of minerals exposed to the percolating fluids, for a realistic evaluation of the rates. These particular features are not included in the available approaches and for that reason a new model was developed, coined THROW model. This is a lumped approach that integrates (T)opography, (H)ydrology, (RO)ck structure and (W)eathering in a single algorithm. The study area comprises several stream watersheds and spring sites of the Vouga River basin (northern Portugal), shaped on granites. Firstly, the THROW model couples a terrain modeling analysis with hydrologic models based on discharge rates, to determine hydraulic conductivities (K), effective porosities (ne) and annual recharges (Vr) at the stream watershed scale. Subsequently, these parameters are used in a water balance model to estimate concomitant groundwater travel times (t). The mean K [(4.7 ± 3.2) × 10-7 m s-1] and ne [(2.0 ± 1.3) × 10-2] values are adopted as proxies for the spring watersheds and a firm regression equation is defined between time and stream watershed area (A). Secondly, two more runs of terrain modeling analysis are executed to extrapolate morphologic parameters for the spring watersheds. The first run hinges on scaling properties of the drainage networks, known as Horton laws, and is used to scale watershed areas across stream orders (i). The scaling function is described by another regression equation. The second run evaluates the order of a spring watershed, defined as equivalent order (ieq) and equated to the mean order of the surrounding stream watersheds. Having

  14. Erosion rates and weathering history of rock surfaces associated with Aboriginal rock art engravings (petroglyphs) on Burrup Peninsula, Western Australia, from cosmogenic nuclide measurements

    NASA Astrophysics Data System (ADS)

    Pillans, Brad; Fifield, L. Keith

    2013-06-01

    The Burrup Peninsula and surrounding Dampier Archipelago, in Western Australia, contain the world's largest known gallery of rock art engravings (petroglyphs), estimated to number up to 1 million images. The peninsula is also the site of major industrial development and there are concerns that industrial emissions may adversely affect the stability and longevity of the rock art. We have studied the natural processes and rates of weathering and erosion, including the effects of fire, that affect the stability of rock surfaces and hence the longevity of the rock art, using cosmogenic nuclides. The concentration of 10Be in quartz yields erosion rates in the range 0.15-0.48 mm/1000 years on horizontal rock surfaces and 0.34-2.30 mm/1000 years on vertical rock faces. The former, largely caused by mm-scale surface flaking, are amongst the lowest erosion rates measured by cosmogenic nuclides anywhere in the world. The latter are inferred to represent a combination of mm-scale flaking and very rare centimetre- to metre-scale block falls, controlled by failure along joint planes. Such low erosion rates result from a combination of resistant rocks, low relief and low rainfall, favouring long-term preservation of the petroglyphs - long enough to encompass the known period of human settlement in Australia.

  15. Fluoride in weathered rock aquifers of southern India: Managed Aquifer Recharge for mitigation.

    PubMed

    Brindha, K; Jagadeshan, G; Kalpana, L; Elango, L

    2016-05-01

    Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoride rich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoride rich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoride rich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5 mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physical or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas. PMID:26822219

  16. Studies of Fe/sup 2 +/. -->. Fe/sup 3 +/ transitions during the process of rock weathering by nuclear gamma-resonance spectroscopy

    SciTech Connect

    Vasil'ev, S.P.; Babanin, V.F.; Solov'ev, A.A.

    1986-11-01

    This paper presents a method for the mineral and weathering assessment of rocks and carbonaceous matter based in gamma spectroscopy and transitions between iron ions. The method is applied to rocks collected near the Teberda preserve. Four latitudinal bands of rocks parallel to the Greater Caucasus Ridge are identified in this territory. Isomer shift and hyperfine parameters of the Moessbauer spectra are given.

  17. Characterizing the process and quantifying the rate of subaerial rock weathering on desert surfaces using roughness analysis

    NASA Astrophysics Data System (ADS)

    Mushkin, Amit; Sagy, Amir; Trabelci, Eran

    2013-04-01

    Subaerial weathering of rocks is a common process observed on desert surfaces on Earth and other planetary terrestrial surfaces such as on Mars. On Earth, this weathering process has been previously identified as one of the key erosion agent driving geomorphic surface evolution and the development of desert pavements. And yet, fundamental aspects of the process, such as the relative contribution of the different weathering modes that drive it (e.g., mechanical breakdown of rocks, chemical weathering, aeolian abrasion and exfoliation) as well as the rate by which this weathering process occurs have not been systematically examined. Here, we present a new approach for quantitatively addressing these fundamental aspects of process geomorphology on desert surfaces. We focus here on co-genetic desert alluvial surfaces of different ages, i.e. alluvial chronosequences, which provide excellent recorders for the evolution of boulder-strewn surfaces into smooth desert pavements through in-situ subaerial weathering of rocks. Our approach combines independent measures of two different surface attributes: High resolution (mm-scale) 3D ground-based laser scanning (LiDAR) of surface micro-topography, and numerical dating of surface age. Roughness analysis of the LiDAR data in power spectral density (PSD) space allows us to characterize the geometric manifestation of rock weathering on the surface and to distinguish between the different weathering modes. Numerical age constraints provide independent estimates for the time elapsed since the process began. Accordingly, we are able to constrain surface roughness evolution on alluvial fan desert chronosequences through time, and present PSD analysis of surface roughness as a new quantitative tool to examine the process of subaerial rock weathering in desert environments. In this study we present results from two late Quaternary alluvial chronosequences along the Dead Sea Transform in the hyper-arid Negev desert of southern Israel. Li

  18. Mismatched Physical and Chemical Weathering of Rocks on Mars: Clues to Past Climate

    NASA Astrophysics Data System (ADS)

    Thomson, B. J.; Hurowitz, J. A.; Baker, L. L.; Bridges, N. T.; Lennon, A.; Paulson, G.; Zacny, K.

    2014-07-01

    Here we quantify the degree of weathering experienced by the Adirondack-class basalts at the MER Spirit site by performing comparative analyses on the strength and chemistry of a series of progressively weathered Columbia River Basalt samples.

  19. Groundwater flows in weathered crystalline rocks: Impact of piezometric variations and depth-dependent fracture connectivity

    NASA Astrophysics Data System (ADS)

    Guihéneuf, N.; Boisson, A.; Bour, O.; Dewandel, B.; Perrin, J.; Dausse, A.; Viossanges, M.; Chandra, S.; Ahmed, S.; Maréchal, J. C.

    2014-04-01

    Groundwater in shallow weathered and fractured crystalline rock aquifers is often the only perennial water resource, especially in semi-arid region such as Southern India. Understanding groundwater flows in such a context is of prime importance for sustainable aquifer management. Here, we describe a detailed study of fracture properties and relate the hydraulic connectivity of fractures to groundwater flows at local and watershed scales. Investigations were carried out at a dedicated Experimental Hydrogeological Park in Andhra Pradesh (Southern India) where a large network of observation boreholes has been set up. Twenty-height boreholes have been drilled in a small area of about 18,000 m2 in which borehole loggings and hydraulic tests were carried out to locate the main flowing fractured zones and investigate fractures connectivity. Several hydraulic tests (nineteen slug tests and three pumping tests) performed under two water level conditions revealed contrasting behavior. Under high water level conditions, the interface including the bottom of the saprolite and the first flowing fractured zone in the upper part of the granite controls groundwater flows at the watershed-scale. Under low water level conditions, the aquifer is characterized by lateral compartmentalization due to a decrease in the number of flowing fractures with depth. Depending on the water level conditions, the aquifer shifts from a watershed flow system to independent local flow systems. A conceptual groundwater flow model, which includes depth-dependent fracture connectivity, is proposed to illustrate this contrasting hydrological behavior. Implications for watershed hydrology, groundwater chemistry and aquifer vulnerability are also discussed.

  20. Examining natural rock varnish and weathering rinds with laser-induced breakdown spectroscopy for application to ChemCam on Mars.

    PubMed

    Lanza, Nina L; Clegg, Samuel M; Wiens, Roger C; McInroy, Rhonda E; Newsom, Horton E; Deans, Matthew D

    2012-03-01

    A laser-induced breakdown spectroscopy (LIBS) instrument is traveling to Mars as part of ChemCam on the Mars Science Laboratory rover. Martian rocks have weathered exteriors that obscure their bulk compositions. We examine weathered rocks with LIBS in a martian atmosphere to improve interpretations of ChemCam rock analyses on Mars. Profile data are analyzed using principal component analysis, and coatings and rinds are examined using scanning electron microscopy and electron probe microanalysis. Our results show that LIBS is sensitive to minor compositional changes with depth and correctly identifies rock type even if the series of laser pulses does not penetrate to unweathered material. PMID:22410929

  1. Water-rock interaction on the development of granite gneissic weathered profiles in Garhwal Lesser Himalaya, India

    NASA Astrophysics Data System (ADS)

    Vyshnavi, S.; Islam, R.

    2015-07-01

    The development and sustainability of weathered profiles are very difficult in the Himalaya due to its complex lithology, tectonic history and fast erosion. Despite this, two weathered profiles namely WPa (weathered profile a) and WPb (weathered profile b) which have sustained erosion are developed on porphyry granite gneiss and granite gneissic lithology in Alaknanda valley of the Garhwal Lesser Himalaya. Systematic sampling of these two weathered profiles was done from bottom to top and they were chemically analysed to understand the elemental mobility in each profile. Major, trace and rare earth element studies show dissimilar behaviour with the advancement of weathering. In WPa profile, the CIA value of LAR (LAR) is 50 which reveals that the rock has not suffered any alteration but in WPb profile, the CIA value of LAR is 64 which indicates significant amount of chemical alteration. A-CN-K projection also exhibits similar behaviour. Further, the relative mobility of all the major and trace elements show variable elemental distribution in both the profiles. Enrichment of Mg, Fe, Ti, Al, Co, Ni, Zr, LREE and depletion of Na, K, P, Ca, Si, LILE and HFSE are observed in WPa profile; while the depletion of Na, K, Ca, P, Si, HREE and enhancement of Fe, Mn, Ti, Sc, Co, Zr, LREE are noticed in WPb profile. The rare earth elements also show a dissimilar mobilization pattern in both the profiles due to their strong dependency on lithology, and corresponding climate and tectonic interaction. Contrasting elemental mobility in both the profiles depict the major role in disparity of lithological characters and subsequent development of fractures produced by the major thrust system (Ramgarh thrust) which made an easy passage for rain water, thus causing the development of a chemically altered profile in the Lesser Himalayan region. Further, the present study infers the climate and tectonic milieu which is responsible for the development of such weathered profiles in Himalayan

  2. A study of the depth of weathering and its relationship to the mechanical properties of near-surface rocks in the Mojave Desert

    USGS Publications Warehouse

    Stierman, D.J.; Healy, J.H.

    1985-01-01

    Weathered granite extends 70 m deep at Hi Vista in the arid central Mojave Desert of southern California. The low strength of this granite is due to the alteration of biotite and chlorite montmorillonite. Deep weathering probably occurs in most granites, although we cannot rule out some anomalous mechanisms at Hi Vista. Geophysical instruments set in these slightly altered rocks are limited by the unstable behavior of the rocks. Thus, tectonic signals from instruments placed in shallow boreholes give vague results. Geophysical measurements of these weathered rocks resemble measurements of granitic rocks near major faults. The rheology of the rocks in which instruments are placed limits the useful sensitivity of the instruments. ?? 1985 Birkha??user Verlag.

  3. Anomalous Features on Anomalous Rocks — Deciphering the Physical Weathering History of Iron Meteorites found on Mars using Terrestrial Analogues

    NASA Astrophysics Data System (ADS)

    Ashley, J.

    2015-12-01

    Non-indigenous rocks (meteorites) found on Mars by rover science teams offer insights into probable recent (mid- to late-Amazonian) weathering processes within 15° of the martian equator. While source materials are often in question for indigenous martian alteration scenarios, the starting materials for most meteorites are known as unweathered, curated falls in Earth-based collections. Both chemical and mechanical weathering processes have modified at least 21 confirmed and candidate exogenic rocks found at three rover landing sites. Such processes have been shown to include acidic corrosion, oxide production, and aeolian scouring. The unknown martian surface exposure duration of the meteorites makes separating physical from chemical weathering effects challenging: Saltating sand grains may accomplish alone what oxidation and rust removal by aeolian scouring may accomplish in a shorter time interval, for example. However, aeolian abrasion appears to dominate for at least some of the surface features in martian irons. Iron meteorites are resistant to wind-blown sand relative to silicate rocks, but are malleable and able to preserve aeolian abrasion effects. These include 1) regmaglypts enlarged into hollows with overhanging cornices; 2) surfaces scalloped or deeply fluted by straight-line groves, and/or 3) deep 'boreholes' present across many surfaces. The flutings, boreholes, and scallops have oriented symmetry and are therefore potentially useful as paleo-wind direction indicators. Boreholes tend to be clean-edged, elliptical to round, of varying diameter, and often occur independently of local topography. Ventifacted igneous rocks found at Garnet Hill, San Gorgonio Pass, California, present features that resemble many aspects of those found in the metal masses on Mars. Though of different petrologies and mineralogies, both rock types are massive, homogeneous and unfractured, which may conceivably account for some apparent similarities in mechanical weathering

  4. Proposal of a New Parameter for the Weathering Characterization of Carbonate Flysch-Like Rock Masses: The Potential Degradation Index (PDI)

    NASA Astrophysics Data System (ADS)

    Cano, M.; Tomás, R.

    2016-07-01

    The susceptibility of clay bearing rocks to weathering (erosion and/or differential degradation) is known to influence the stability of heterogeneous slopes. However, not all of these rocks show the same behaviour, as there are considerable differences in the speed and type of weathering observed. As such, it is very important to establish relationships between behaviour quantified in a laboratory environment with that observed in the field. The slake durability test is the laboratory test most commonly used to evaluate the relationship between slaking behaviour and rock durability. However, it has a number of disadvantages; it does not account for changes in shape and size in fragments retained in the 2 mm sieve, nor does its most commonly used index (Id2) accurately reflect weathering behaviour observed in the field. The main aim of this paper is to propose a simple methodology for characterizing the weathering behaviour of carbonate lithologies that outcrop in heterogeneous rock masses (such as Flysch slopes), for use by practitioners. To this end, the Potential Degradation Index (PDI) is proposed. This is calculated using the fragment size distribution curves taken from material retained in the drum after each cycle of the slake durability test. The number of slaking cycles has also been increased to five. Through laboratory testing of 117 samples of carbonate rocks, extracted from strata in selected slopes, 6 different rock types were established based on their slaking behaviour, and corresponding to the different weathering behaviours observed in the field.

  5. Effects of Weathering at Waste Rock Dump on Water Quality Inside the Mine Wastes; A Case Study in Korea

    NASA Astrophysics Data System (ADS)

    Yim, G.; Cheong, Y.; Park, H.; Ji, S.; Lee, H.

    2008-05-01

    This study was carried out to investigate the route of acid rock drainage production and some of the important factors at the abandoned Geo-pung copper mine in Okcheon, Korea. In this research area, planting and remediation have been carried out to prevent environmental pollution, but these effects turned out to be a failure and that acid rock drainage is observed around waste rock dump and planted vegetation is dying. Currently, the slope of mine waste rock dump in the study site is about 40°. It is composed of particles with a variety of shapes, with the surface exposure to atmosphere being transformed to oxide minerals due to weathering. Since groundwater level underneath the mine wastes is directly related to rainfall, a comparative evaluation of weather records and groundwater level data obtained using on-site measuring device (CTD diver) would allow estimation of locational media-specific pattern of rainfall effect in term of infiltration flux and time of threshold impact on groundwater. Sampling and analysis of there borehole water were conducted in July and September, 2007. It was found that all of the borehole water had highly variable levels of Fe (0.4-588 mg/l), Al (8.2-41.9 mg/l), Cu (6.0-32.2 mg/l), Zn (22.2-226.7 mg/l) and other elements. Also, in general, pH of the borehole waters decreased while electric conducivity measured. Such a high variance in the water quality among different borehole water suggests that geochemical environment inside the mine wastes is largely dependent on the local variation in rainfall infiltration of waste rock dump and underneath groundwater level. Vadose zone which has vertical variation of 2-4 m is directly impacted by amount of rainfall and maintains oxidizing condition due to diffusion of oxygen carred by rainfall. Therefore, sulfide minerals within in the zone continued to be oxidized, producing acid rock drainage. To prevent production of acid rock drainage of mine waste, it is necessary to control infiltration of

  6. Rock and stone weathering at Citadel fortifications, Gozo (Malta): benefits from terrestrial laser scanning combined with conventional investigations

    NASA Astrophysics Data System (ADS)

    Tapete, D.; Gigli, G.; Mugnai, F.; Vannocci, P.; Pecchioni, E.; Morelli, S.; Fanti, R.; Casagli, N.

    2012-04-01

    Military architecture heritage is frequently built on rock masses affected by slope instability and weathering processes, which progressively undermine the foundations and cause collapses and toppling of the masonries. The latter can be also weakened by alteration of the stone surfaces, as a consequence of the interactions with the local environmental conditions. These conservation issues are emphasized for those sites, whose susceptibility to structural damages is also due to the similarity between the lithotypes constituting the geologic substratum and the construction materials. Effective solutions for the protection from such a type of phenomena can be achieved if the whole "rock mass - built heritage system" is analyzed. In this perspective, we propose a new approach for the study of the weathering processes affecting historic hilltop sites, taking benefits from the combination of terrestrial laser scanning (TLS) and conventional investigations, the latter including geotechnical and minero-petrographic analyses. In particular, the results here presented were obtained from specific tests on the fortifications of Citadel, Gozo (Malta), performed in co-operation with the Restoration Unit, Works Division, Maltese Ministry for Resources and Rural Affairs and the private company Politecnica Ingegneria e Architettura. The Citadel fortifications are built at the top of a relatively stiff and brittle limestone plate, formed by Upper Coralline Limestone (UCL) and overlying a thick Blue Clay (BC) layer. Differential weathering creates extensively fractured ledges on the cap and erosion niches in the strata beneath, thereby favouring block detachment, even rockfall events, such as the last one occurred in 2001. The locally quarried Globigerina Limestone (GL), historically employed in restoration masonries, is also exposed to alveolization and powdering, and several collapses damaged the underwalling interventions. Since the erosion pattern distribution suggested a

  7. High-Silica Rock Coatings on Mars: Constraining Secondary Silicate Mineralogy and Chemical Weathering Processes on Mars.

    NASA Astrophysics Data System (ADS)

    Kraft, M. D.; Michalski, J. R.; Sharp, T. G.

    2003-12-01

    Thermal Emission Spectrometer (TES) data have been fundamental to understanding Martian surface mineralogy. These data, however, require careful modeling based on laboratory spectroscopic measurements, and modeling of some minerals for Mars has been equivocal. Due to high degrees of spectral similarity, it is difficult to distinguishing silicate glass, clay minerals, zeolites, palagonitized glass, and other secondary products such as amorphous silica as components of surface rock spectra. Deciphering the nature of secondary mineral products on Mars is of key importance to understanding the role of water at the Martian surface over time. It is of central interest to distinguish primary glass from secondary silicate minerals, and secondary minerals from one another to better constrain the degree and mechanisms of aqueous alteration. Observations of Martian surface materials indicate some degree of atmosphere-water-rock interaction. These include nanophase ferric-iron oxides from visible/near-infrared spectroscopy, concentrated hematite deposits identified with TES, high water contents of rocks measured by the Alpha Proton X-ray Spectrometer, sulfate and halide minerals inferred from lander geochemical measurements, and carbonate minerals identified in Martian dust with TES data. Mass balance suggests that if there are oxides, salts, and carbonates there must also be secondary silicate phases present on Mars, which may be identifiable with TES. Identifying the types, distribution, and abundance (or absence) of secondary silicates will enable better constrains to be placed on Martian chemical weathering processes and the role water has played at the Martian surface. We suggest that rock coatings dominated by amorphous silica are geologically reasonable for Mars and may be consistent with TES data. Laboratory measurements of silica-coated rocks show that thin, micrometer-scale silica coatings have a substantial impact on rock spectra. Consequently, if authegenic

  8. Accelerated weathering of carbonate rocks following the 2010 forest wildfire on Mt. Carmel, Israel

    NASA Astrophysics Data System (ADS)

    Shtober-Zisu, Nurit; Tessler, Naama; Tsatskin, Alexander; Greenbaum, Noam

    2015-04-01

    Massive destruction of carbonate rocks occurred on the slopes of Mt. Carmel, during the severe forest fire in 2010. The bedrock surfaces exhibited extensive exfoliation into flakes and spalls covering up to 80%-100% of the exposed rocks; detached boulders were totally fractured or disintegrated. The fire affected six carbonate units -- various types of chalk, limestone, and dolomite. The burned flakes show a consistent tendency towards flatness, in all lithologies, as 85%-95% of the flakes were detached in the form of blades, plates, and slabs. The effects of the fire depend to a large extent on the rocks' physical properties and vary with lithology: the most severe response was found in the chalk formations which are covered by calcrete (Nari crusts). These rocks reacted by extreme exfoliation, at an average depth of 7.7 to 9.6 cm and a maximum depth of 20 cm. The flakes formed in chalk were thicker, longer, and wider than those of limestone or dolomite formations. Moreover, the chalk outcrops were exfoliated in a laminar structure, one above the other, to a depth of 10 cm and more. Their shape also tended to be blockier or rod-like. In contrast, the limestone flakes were the thinnest, with 99% of them shaped like blades and plates. Scorched and blackened faces under the upper layer of spalls provided strong evidence that chalk breakdown took place at an early stage of the fire. The extreme response of the chalks can be explained by the laminar structure of the Nari, which served as planes of weakness for the rock destruction. Three years after the fire, the rocks continue to exfoliate and break down internally. As the harder surface of the Nari was removed, the more brittle underlying chalk is exposed to erosion. If fires can obliterate boulders in a single wildfire event, it follows that wildfires may serve as limiting agents in the geomorphic evolution of slopes. However, it is difficult to estimate the frequency of high-intensity fires in the Carmel region

  9. Weathering profiles in granitoid rocks of the Sila Massif uplands, Calabria, southern Italy: New insights into their formation processes and rates

    NASA Astrophysics Data System (ADS)

    Scarciglia, Fabio; Critelli, Salvatore; Borrelli, Luigi; Coniglio, Sabrina; Muto, Francesco; Perri, Francesco

    2016-05-01

    In this paper we characterized several weathering profiles developed on granitoid rocks in the Sila Massif upland (Calabria, southern Italy), integrating detailed macro- and micromorphological observations with physico-mechanical field tests and petrographic, mineralogical and geochemical analyses. We focused our attention on the main weathering and pedogenetic processes, trying to understand apparent discrepancies between weathering grade classes based on field description and geomechanical properties, and two common weathering indices, such as the micropetrographic index (Ip) and the chemical index of alteration (CIA). Our results showed that sericite on plagioclase and biotite chloritization, that represent inherited features formed during late-stage hydrothermal alteration of granitoid rocks, may cause an overestimation of the real degree of weathering of primary mineral grains under meteoric conditions, especially in lower weathering grade classes. Moreover, the frequent identification of Fe-Mn oxides and clay coatings of illuvial origin (rather than or in addition to those formed in situ), both at the macro- and microscale, may also explain an overestimation of the weathering degree with respect to field-based classifications. Finally, some apparent inconsistencies between field geomechanical responses and chemical weathering were interpreted as related to physical weathering processes (cryoclastism and thermoclastism), that lead to rock breakdown even when chemical weathering is not well developed. Hence, our study showed that particular caution is needed for evaluating weathering grades, because traditional field and geochemical-petrographic tools may be biased by inherited hydrothermal alteration, physical weathering and illuvial processes. On the basis of chronological constraints to soil formation obtained from a 42 ka-old volcanic input (mixed to granite parent materials) detected in the soil cover of the Sila Massif upland, a first attempt to estimate

  10. Venus - Chemical weathering of igneous rocks and buffering of atmospheric composition

    NASA Technical Reports Server (NTRS)

    Nozette, S.; Lewis, J. S.

    1982-01-01

    Data from the Pioneer Venus radar mapper, combined with measurements of wind velocity and atmospheric composition, suggest that surface erosion on Venus varies with altitude. Calcium- and magnesium-rich weathering products are produced at high altitudes by gas-solid reactions with igneous minerals, then removed into the hotter lowlands by surface winds. These fine-grained weathering products may then rereact with the lower atmosphere and buffer the composition of the observed gases carbon dioxide, water vapor, sulfur dioxide, and hydrogen fluoride in some regions of the surface. This process is a plausible mechanism for the establishment in the lowlands of a calcium-rich mineral assemblage, which had previously been found necessary for the buffering of these species.

  11. Venus: chemical weathering of igneous rocks and buffering of atmospheric composition.

    PubMed

    Nozette, S; Lewis, J S

    1982-04-01

    Data from the Pioneer Venus radar mapper, combined with measurements of wind velocity and atmospheric composition, suggest that surface erosion on Venus varies with altitude. Calcium- and magnesium-rich weathering products are produced at high altitudes by gas-solid reactions with igneous minerals, then removed into the hotter lowlands by surface winds. These fine-grained weathering products may then rereact with the lower atmosphere and buffer the composition of the observed gases carbon dioxide, water vapor, sulfur dioxide, and hydrogen fluoride in some regions of the surface. This process is a plausible mechanism for the establishment in the lowlands of a calcium-rich mineral assemblage, which had previously been found necessary for the buffering of these species. PMID:17736250

  12. Reach-scale evidence for feedbacks among chemical weathering, rock strength and erosion in bedrock rivers across Kohala Peninsula, Hawai'i

    NASA Astrophysics Data System (ADS)

    Murphy, B. P.; Johnson, J. P.; Gasparini, N. M.; Hancock, G. S.; Small, E. E.

    2015-12-01

    Bedrock river downcutting is usually conceptualized in terms of shear-stress dependent erosion processes, such as abrasion and plucking. Many studies of climatic control on erosion have focused on the effect of rainfall rate on discharge. However, the erodibility of bedrock can also be influenced by climate-dependent chemical weathering. We show that this mechanism can not only influence erosion patterns and rates, but also reach-scale bedrock topography. First, we present a new numerical model that describes and explores the feedbacks among chemical weathering, rock strength and erosion rate. Second, we present reach-scale field data demonstrating interactions among chemical weathering, rock strength, abrasion, and channel morphology. Across an extreme rainfall gradient on Kohala Peninsula, Hawai'i, we demonstrate that bedrock chemical weathering leads to the development of significant asymmetries in rock strength across features that are exposed to abrasion. Using a type-N Schmidt hammer, we measured the in-situ rock strength across 23 morphologic features of bedrock exposed in the stream beds of rivers, and found that upstream faces are consistently stronger, by an average of 38%, than downstream faces. Measured rock strengths suggest that the erodibilty of downstream (lee) faces may be as much as 20 times higher than corresponding upstream faces where weaker weathered material is efficiently abraded away. The asymmetrical pattern of rock strength does not necessarily lead to strongly asymmetrical morphologies, because although sediment impacts may result in more erosion on the weaker downstream face, the frequency of abrasion wear is substantially less frequent. Although the physical evidence for the chemical weathering is more frequently removed from the upstream face, these results demonstrate that, particularly in regions with higher local rainfall and weathering rates, chemical weathering induced strength reduction is a specific mechanism by which climate

  13. In search for coastal amplification of rock weathering in polar climates - pilot Schmidt hammer rock tests surveys from sheltered fjords of Svalbard and tsunami-affected coasts of Western Greenland.

    NASA Astrophysics Data System (ADS)

    Strzelecki, Matt

    2014-05-01

    Recent decade has seen the major advance in Arctic coastal geomorphology due to research progress along ice-rich permafrost coastlines of Siberia, Alaska and NW Canada. On the contrary little attention was paid to Arctic rocky coastlines and their response to the reduction of sea ice cover and increased number of storms reaching Arctic region. In this paper I present results from a pilot survey of rock resistance using Schmidt Hammer Rock Tests across rocky cliffs and shore platforms developed in: - sheltered bays of Billefjorden, Svalbard characterised by prolonged sea-ice conditions and very limited operation of wave and tidal action - Vaigat Strait and Isfjorden in W Greenland influenced by landslide-triggered tsunamis and waves induced by ice-berg roll events. The aim of a pilot study was to test the hypothesized coastal impact on the rate of rock weathering in polar climates. To do so I characterise the changes in the rock resistance on the following coastal landforms: - modern and uplifted wave-washed abrasion platforms- focusing on a relation between the degree of rock surface weathering and the distance from the shoreline as well as thickness of sediment cover on shore platform surface - modern and uplifted rocky cliffs - focusing on a relation between the degree of rock surface weathering and the distance from the shoreline as well as difference in height above the sea level and relation to rock lithology. The results present another line of argument supporting intensification of rock weathering processes in the Arctic coastal zone. This work is a contribution to the National Science Centre in Poland research project no. 2011/01/B/ST10/01553.

  14. The breath of the rocks: Lake carbon dioxide emissions from weathering processes at the global scale

    NASA Astrophysics Data System (ADS)

    Marcé, R.; Obrador, B.

    2014-12-01

    Most lakes and reservoirs are known to have surface carbon dioxide (CO2) concentrations that are supersaturated with respect to the atmosphere, and hence nearly all of them are net emitters of CO2. Global carbon emissions from lakes account for 0.06 to 0.84 Pg C year-1, a substantial amount relative to other fluxes of the continental C balance. Therefore, a proper understanding of the land carbon cycle and its sensitivity to external perturbations requires detailed knowledge of drivers of global CO2 supersaturation in lakes. CO2 supersaturation has generally been attributed to a widespread imbalance of lake net ecosystem production towards net heterotrophy, but recent findings challenge this interpretation. Here we show that an integrated perspective including lake net ecosystem production together with precipitation and dissolution of carbonate minerals and inputs of dissolved inorganic carbon from the watershed, substantially improves our understanding of the processes leading to CO2 supersaturation in lakes with alkalinity above 1 meq L-1. Our results indicate that CO2 supersaturation is independent of net ecosystem production in many lakes, and that a significant amount of the CO2 evaded through their surface is directly related to weathering processes in the watershed that supply alkalinity to surface waters. After evaluation of the worldwide distribution of alkalinity across lakes we show that CO2 emissions related to weathering processes are relevant in tropical and temperate latitudes, but negligible in boreal regions.

  15. Effect of Weathering Processes on Mineralogical and Mechanical Properties of Volcanic Rocks Used as Ballast Material for Railway Between Sabuncupinar and Kütahya in Western Turkey

    NASA Astrophysics Data System (ADS)

    Abiddin Erguler, Zeynal; Adıgüzel, Ömer; Derman, Mustafa

    2015-04-01

    Geomaterials used in engineering projects and man-made structures such as railway ballasts, buildings, historical structures, monuments and tombstones naturally weather as a result of various physico-chemical factors. Due to being long-term exposure to the anthroposphere, geomaterials used for these purposes provides important information to the researchers for understanding the effect of weathering processes on their time dependent physical, mineralogical and mechanical changes. Thus, researchers frequently can take advantage of available engineering time of man-made structures to assess weathering properties of the geomaterials used in their construction in terms of time dependent durability and stability of these structures. Considering the fact that railway ballasts produced from natural deposits of limestone, dolomite, granite, basalt etc., supply an important contribution for evaluation weathering processes, a research was carried out to determine the effect of weathering as a function of time on physical, mineralogical and mechanical properties of ballasts used for railway between Kütahya and Sabuncupınar in western Turkey. For this purpose, fresh and weathered rock samples exposed to physical and chemical weathering processes at different times were collected from quarry located in Sabuncupınar and nearby railway. This volcanic rock was previously classified as basalt based on the detailed mineralogical and geochemical analyses performed at the laboratories of the Mineral Research & Exploration General Directorate located in Ankara (Turkey). In-situ characteristics of sampling site were also investigated at different locations of quarry site by line surveying technique to describe the influence of discontinuity conditions on the weathering rate of selected rocks. Several techniques were utilized to determine time dependent deterioration in mineralogical and chemical composition of these samples for understanding their weathering rate. The porosity, water

  16. Rocks.

    ERIC Educational Resources Information Center

    Lee, Alice

    This science unit is designed for limited- and non-English speaking students in a Chinese bilingual education program. The unit covers rock material, classification, characteristics of types of rocks, and rock cycles. It is written in Chinese and simple English. At the end of the unit there is a list of main terms in both English and Chinese, and…

  17. Spatial and temporal variation of uranium in a shallow weathered rock aquifer in southern India

    NASA Astrophysics Data System (ADS)

    Brindha, K.; Elango, L.; Nair, R. N.

    2011-10-01

    Uranium occurs naturally in groundwater and surface water. The objective of this study is to understand the causes for the occurrence of uranium and its spatio-temporal variation in groundwater in a part of Nalgonda district, Andhra Pradesh, south India. Uranium deposits occur in the southeastern part of this area. Groundwater samples were collected from 44 wells every two months from March 2008 to January 2009. The samples were analyzed for pH, ORP and uranium concentration. The uranium concentration in groundwater varies from 0.2 ppb to a maximum of 68 ppb with a mean of 18.5 ppb. About 21.6% of the samples were above the drinking water limit of 30 ppb set by USEPA. The uranium concentration varied with fluctuation in groundwater level, pH and ORP. Uranium concentration in groundwater changes depending on lithology, degree of weathering and rainfall recharge.

  18. Weathering of Basaltic Rocks from the Gusev Plains up into the Columbia Hills from the Perspective of the MER Mossbauer Spectrometer

    NASA Technical Reports Server (NTRS)

    Schroeder, C.; Klingelhoefer, G.; Morris, R. V.; Rodionov, D. S.; deSouza, P. A.; Ming, D. W.; Yen, A. S.; Gellert, R.; Bell, J. F., III

    2005-01-01

    Rocks on the ejecta blanket of Bonneville crater and along Spirit s traverse over the Gusev plains towards the Columbia Hills are angular and strewn across the surface. They have a basaltic composition [1,2], and their Mossbauer spectra are dominated by an olivine doublet [1]. The ubiquitous presence of abundant olivine in rocks and in surrounding soil suggests that physical rather than chemical weathering processes currently dominate the plains at Gusev crater [1]. However, MB spectra of rocks and outcrops in the Columbia Hills suggest more aggressive alteration processes have occurred. Ascending into the hills, Spirit encountered outcrop and rocks exhibiting layered structures. Some scattered rocks at the foot of the Columbia Hills appeared "rotten" or highly altered by physical and/or chemical processes (fig. 1). Mossbauer spectra of those rocks show a decrease in olivine accompanied by an increase in the Fe-oxides magnetite, hematite, and nanophase Fe3+ -oxides (fig. 2), suggesting that chemical weathering processes in the presence of water have altered these rocks and outcrops.

  19. Experimental Acid Weathering of Fe-Bearing Mars Analog Minerals and Rocks: Implications for Aqueous Origin of Hematite-Bearing Sediments in Meridiani Planum, Mars

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Koster, A. M.; Ming, D. W.; Morris, R. V.; Mertzman, S. A.

    2011-01-01

    A working hypothesis for Meridiani evaporite formation involves the evaporation of fluids derived from acid weathering of Martian basalts and subsequent diagenesis [1, 2]. However, there are no reported experimental studies for the formation of jarosite and gray hematite (spherules), which are characteristic of Meridiani rocks from Mars analog precursor minerals. A terrestrial analog for hematite spherule formation from basaltic rocks under acidic hydrothermal conditions has been reported [3], and we have previously shown that the hematite spherules and jarosite can be synthetically produced in the laboratory using Fe3+ -bearing sulfate brines under hydrothermal conditions [4]. Here we expand and extend these studies by reacting Mars analog minerals with sulfuric acid to form Meridiani-like rock-mineral compositions. The objective of this study is to provide environmental constraints on past aqueous weathering of basaltic materials on Mars.

  20. The effects of weathering on the strength and chemistry of Columbia River Basalts and their implications for Mars Exploration Rover Rock Abrasion Tool (RAT) results

    NASA Astrophysics Data System (ADS)

    Thomson, B. J.; Hurowitz, J. A.; Baker, L. L.; Bridges, N. T.; Lennon, A. M.; Paulsen, G.; Zacny, K.

    2014-08-01

    Basalt physical properties such as compressive strength and density are directly linked to their chemistry and constitution; as weathering progresses, basalts gradually become weaker and transition from intact rock to saprolite and ultimately, to soil. Here we quantify the degree of weathering experienced by the Adirondack-class basalts at the Mars Exploration Rover Spirit site by performing comparative analyses on the strength and chemistry of a series of progressively weathered Columbia River Basalt (CRB) from western Idaho and eastern Washington. CRB samples were subjected to compressive strength tests, Rock Abrasion Tool grinds, neutron activation analysis, and inductively coupled plasma optical emission spectroscopy. Analyses of terrestrial basalts indicate linked strength-chemical changes, as expected. Weathering sufficient to induce the loss of more than 50% of some cations (including >50% of MgO and MnO as well as ∼38% of Fe2O3 and 34% of CaO) was observed to weaken these samples by as much as 50% of their original strength. In comparison with the terrestrial samples, Adirondack-class basalts are most similar to the weakest basalt samples measured in terms of compressive strength, yet they do not exhibit a commensurate amount of chemical alteration. Since fluvial and lacustrine activity in Gusev crater appears to have been limited after the emplacement of flood basalt lavas, the observed weakness is likely attributable to thin-film weathering on exposed, displaced rocks in the Gusev plains (in addition to some likely shock effects). The results indicate that Adirondack-class basalts may possess a several mm-thick weak outer rind encasing an interior that is more pristine than otherwise indicated, and also suggest that long rock residence times may be the norm.

  1. Determination of Granite Rock Massif Weathering and Cracking of Surface Layers in the Oldest Parts of Medieval Mine Depending on Used Mining Method

    NASA Astrophysics Data System (ADS)

    Lednická, Markéta; Kaláb, Zdeněk

    2016-06-01

    The paper presents the use of selected non-destructive testing methods for the purpose of specifying information on weathering and cracking of surface layers of granite rock massif in the medieval Jeroným Mine (the Czech Republic). This mine has been declared the National Heritage Site of the Czech Republic and its opening as a mining museum to the public is gradually prepared. Geological and geomechanical evaluation documents the possibility to find all kinds of weathering grades of rock massif in this mine. Two non-destructive methods have been tested, namely the measurement of ultrasonic pulse velocity and the measurement of Schmidt hammer rebound value. Field measurements were performed in two selected galleries to verify the application of such methods in specific conditions of underground spaces. Used mining method is one of the parameters later influencing cracking of rock massif. In selected galleries, two different mining methods were used which means that a part of a gallery profile was mined out by hand tools in the Middle Ages and another part of the profile was later mined out by blasting. Measurements in these galleries have enabled to analyse the influence of used mining methods on cracking of rock massif in the impaired zone, and, consequently, on ongoing weathering processes in those zones.

  2. Characterization and petrophysical properties of hydrothemally altered lacustrine volcanistic rock in Geyser Valley (Kamchatka) and its transformation by weathering

    NASA Astrophysics Data System (ADS)

    Gvozdeva, Irina; Zerkal, Oleg; Samarin, Evgeny

    2013-04-01

    smectite causes high hygroscopy of deposits. Rocks are highly porous - of 37-65%, primarily low density - 0,9-1,65 g/cm3 wave velocities - from 0.74 km/s for porous to 3.42 km/sec for dense varieties. All samples are characterized by low strength characteristics: uniaxial compressive strength - 1.2 - 21.7 MPa, uniaxial tension - 0,6-4,7 MPa. By water saturation strength decreases rapidly. Soft coefficient ranges from 0.22 to 0.57. Proving to be on the land surface as a result of slope deformation, volcanic-sedimentary hydrothermally altered rocks are destroyed quickly by precipitation and temperature fluctuations Rock turned to sand, silt and clay depending on the original composition. It was found that often weathered to clayey state tuffites inherit structural and textural features of the primary species. The composition also varies: increased content of clay minerals (to 90%), decreasing the content of zeolites (not to exceed 10%). Quartz and plagioclase form sans fraction. Physical and mechanical properties vary widely: the density of the soil increases slightly up to 1,57-1,59 g/cm3 for sands, 1,2-1,79 g/cm3 for clays, porosity of 51-52% and 49-78% respectively, moisture 22-23% and 43-98/ Clays are in a state of semi-solid to fluid. The high content of smectite determines high plastic properties. Plasticity Index varies widely from 11 to 57. Cohesion and the internal friction angle obtained from shear tests also change widely. For clayey sand grip reaches 137 kPa, internal friction angle - 17 degrees. In clay grip ranges from 13 kPa to 120 kPa, and the internal friction angle - from 11 degrees to 31 degrees. Large variation of properties of the investigated soils is explained by the inhomogeneity of volcano-sedimentary formations both vertically and laterally, varying degrees of hydrothermal alteration and of weathering, fracturing and cracks filling The obtained datas can adequately characterize the volcanic-lacustrine sediments in the valley of the Geysernaya river

  3. Interstratified vermiculite-mica in the gneiss-metapelite-serpentinite rocks at Hafafit area, Southern Eastern Desert, Egypt: From metasomatism to weathering

    NASA Astrophysics Data System (ADS)

    Harraz, H. Z.; Hamdy, M. M.

    2010-09-01

    The Hafafit vermiculite in the Southern Eastern Desert of Egypt at the contact of the metapelite and serpentinite rocks with the pegmatites and gneisses of the Hafafit uplift is the only known deposit in the Arabian-Nubian Shield (ANS) rocks of the Eastern Desert (ED). It is distinctively interstratified with mica. The mineralogy and mineral chemistry of this vermiculite at four sites (HV1, HV2, HV3 and HV4) were studied to better understand its origin, which might refers to a specific geologic setting retained to Hafafit area. The vermiculite at Hafafit forms with phlogopite, actinolite-tremolite, asbestos-anthophyllite-talc and talc zones that are arranged from pegmatite and gneisses to the metapelite and serpentinite rocks. These zones were probably formed by metasomatism that related to the intrusion of the granitoid rocks and the connected pegmatites in the upper Pan-African. The XRD and EMPA studies of the interstratified vermiculite-mica concluded that vermiculitization took place through a layer-by-layer transformation of original micas. This formed, in decreasing abundance, mixed-layer phases of biotite/vermiculite (hydrobiotite), phlogopite/vermiculite (hydrophlogopite) and chlorite/vermiculite (corrensite) and discrete phases of vermiculite, chlorite and smectite. A model is suggested, in which chemical weathering by the moving downward meteoric water led to replacement of the interlayer K, in biotite from gneiss and in phlogopite from metasomatic zones, by H 2O molecules, Fe 2+ was oxidized and (OH) - replaced O 2- forming hydrobiotite and hydrophlogopite. By more K remove, Fe was replaced by Mg with the introduction of more layers of H 2O molecules leading to formation of the vermiculite. Weathering formed corrensite mixed-layer and chlorite expandable minerals on the expense of chlorite. Formation of the incomplete smectite-like layers and Al-hydroxy interlayers (13.97 Ǻ) took place at the expense of vermiculite, replacing the Mg interlayer cations

  4. Distribution of Sc, Ta, Hf, Zr, Co, and Fe in the crust of weathering of metalliferous gabbro-norites in volodarsk-volyn rock body

    SciTech Connect

    Borisenko, L.F.; Chudinov, V.I.

    1986-09-01

    Nuclear physics methods are used to determine the Sc, Ta, Hf, Zr, Co, and Fe contents in gabbro-norites and the component minerals of these rocks, as well as in the various zones of the crusts of weathering developed on gabbro-norites. It has been established that Sc, Ta, Hf, and Zr accumulate in the kaolinite zone, but Co is partly washed out of it.

  5. Behavior of major and trace elements upon weathering of peridotites in New Caledonia : A possible site on ultramafic rocks for the Critical Zone Exploration Network (CZEN) ?

    NASA Astrophysics Data System (ADS)

    Juillot, Farid; Fandeur, D.; Fritsch, E.; Morin, G.; Ambrosi, J. P.; Olivi, L.; Cognigni, A.; Hazemann, J. L.; Proux, O.; Webb, S.; Brown, G. E., Jr.

    2010-05-01

    Ultramafic rocks cover about 1% of the continental surfaces and are related to ophiolitic bodies formed near convergent plate boundaries (Coleman, 1977). The most typical ultramafic rocks are dunite and harzburgite, which are composed of easily weatherable ferromagnesian mineral species (olivines and pyroxenes), but also of more resistant spinels (chromite and magnetite). Oceanic serpentinization of these ultramafic rocks usually lead to partial transformation of these initial mineral assemblages by forming hydrous layer silicates such as serpentine (lizardite, chrysotile and antigorite) talc, chlorite and actinolite (Malpas, 1992). It also lead to the formation of highly sheared textures, which favor meteoric weathering through preferential water flows. Compared to their crystalline rock counterpart that covers most of the continental surfaces, these ultramafic rocks mainly differ by their lower SiO2, Al2O3 and K2O contents (less than 50%, 10% and 1%, respectively) and, on the opposite, much higher MgO content (more than 18%). Moreover, they commonly have higher concentrations in FeO and other trace elements, such as Ni, Cr, Mn and Co. Weathering of these rocks is then at the origin of major geochemical anomalies on continental surfaces, especially when they occur in tropical and subtropical regions. Such conditions are encountered in New Caledonia where one third of the surface is covered with peridotites (mainly harzburgite with small amounts of dunite) obducted about 35 millions years ago during large tectonic events in the Southwest Pacific at the Late Eocene (Cluzel et al., 2001). Tropical weathering of these ultramafic rocks lead to the development of thick lateritic regoliths where almost all Mg and Si have been leached out and Fe, Mn, Ni, Cr and Co have been relatively concentrated. In these oxisols, Ni, Cr and Co can exhibit concentration up to several wt%, which make them good candidates for ore mining (New Caledonia is the third Ni producer in the world

  6. Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions

    NASA Astrophysics Data System (ADS)

    Guglielmin, Mauro; Worland, M. Roger; Baio, Fabio; Convey, Peter

    2014-11-01

    In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between - 3.7 and - 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze-thaw events were negligible (0-3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual

  7. Petrography and geochemistry of Cretaceous to quaternary siliciclastic rocks in the Tarfaya basin, SW Morocco: implications for tectonic setting, weathering, and provenance

    NASA Astrophysics Data System (ADS)

    Ali, Sajid; Stattegger, Karl; Garbe-Schönberg, Dieter; Kuhnt, Wolfgang; Kluth, Oliver; Jabour, Haddou

    2014-01-01

    The petrography, heavy mineral analysis, major element geochemical compositions and mineral chemistry of Early Cretaceous to Miocene-Pliocene rocks, and recent sediments of the Tarfaya basin, SW Morocco, have been studied to reveal their depositional tectonic setting, weathering history, and provenance. Bulk sediment compositional and mineral chemical data suggest that these rocks were derived from heterogeneous sources in the Reguibat Shield (West African Craton) including the Mauritanides and the western Anti-Atlas, which likely form the basement in this area. The Early Cretaceous sandstones are subarkosic in composition, while the Miocene-Pliocene sandstones and the recent sediments from Wadis are generally carbonate-rich feldspathic or lithic arenites, which is also reflected in their major element geochemical compositions. The studied samples are characterized by moderate SiO2 contents and variable abundances of Al2O3, K2O, Na2O, and ferromagnesian elements. Binary tectonic discrimination diagrams demonstrate that most samples can be characterized as passive continental marginal deposits. Al2O3/Na2O ratios indicate more intense chemical weathering during the Early Cretaceous and a variable intensity of weathering during the Late Cretaceous, Early Eocene, Oligocene-Early Miocene, Miocene-Pliocene and recent times. Moreover, weathered marls of the Late Cretaceous and Miocene-Pliocene horizons also exhibit relatively low but variable intensity of chemical weathering. Our results indicate that siliciclastics of the Early Cretaceous were primarily derived from the Reguibat Shield and the Mauritanides, in the SW of the basin, whereas those of the Miocene-Pliocene had varying sources that probably included western Anti-Atlas (NE part of the basin) in addition to the Reguibat Shield and the Mauritanides.

  8. Stages of weathering mantle formation from carbonate rocks in the light of rare earth elements (REE) and Sr-Nd-Pb isotopes

    NASA Astrophysics Data System (ADS)

    Hissler, Christophe; Stille, Peter

    2015-04-01

    Weathering mantles are widespread and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved rocks. These old regolith systems have a complex history of formation and may present a polycyclic evolution due to successive geological and pedogenetic processes that affected the profile. Until now, only few studies highlighted the unusual high content of associated trace elements in weathering mantles originating from carbonate rocks, which have been poorly studied, compared to those developing on magmatic bedrocks. For instance, these enrichments can be up to five times the content of the underlying carbonate rocks. However, these studies also showed that the carbonate bedrock content only partially explains the soil enrichment for all the considered major and trace elements. Up to now, neither soil, nor saprolite formation has to our knowledge been geochemically elucidated. Therefore, the aim of this study was to examine more closely the soil forming dynamics and the relationship of the chemical soil composition to potential sources. REE distribution patterns and Sr-Nd-Pb isotope ratios have been used because they are particularly well suited to identify trace element migration, to recognize origin and mixing processes and, in addition, to decipher possible anthropogenic and/or "natural" atmosphere-derived contributions to the soil. Moreover, leaching experiments have been applied to identify mobile phases in the soil system and to yield information on the stability of trace elements and especially on their behaviour in these Fe-enriched carbonate systems. All these geochemical informations indicate that the cambisol developing on such a typical weathering mantle ("terra fusca") has been formed through weathering of a condensed Bajocian limestone-marl facies. This facies shows compared to average world carbonates important trace element enrichments. Their trace element distribution patterns are similar to those of the soil

  9. Deciphering post-Deccan weathering and erosion history of South Indian Archean rocks from cryptomelane 40Ar-39Ar dating

    NASA Astrophysics Data System (ADS)

    Bonnet, Nicolas; Arnaud, Nicolas; Beauvais, Anicet; Chardon, Dominique

    2015-04-01

    Since the extrusion of Deccan traps ~ 63 Ma ago, weathering and erosion processes have shaped the landscapes of this Peninsula India. This resulted in pervasive bauxitic weathering on traps and deep lateritic weathering of their basement on either side of the Western Ghats Escarpment, which separates a coastal lowland from an East-dipping highland plateau. Mn-rich lateritic profiles formed by supergene weathering of Late Archean manganiferous protores in the different greenstone belts are exposed on relict paleosurfaces, which are preserved at different elevations on the highland plateau and in the coastal lowland, allowing for direct comparison of paleosurfaces and geomorphological processes across one of the most prominent relief in the Indian peninsula. Detailed petrological and geochemical investigations of samples collected in the different Mn-rich lateritic profiles allowed for precise characterization of cryptomelane [Kx Mn8-xIV MnxIII O16, nH2O], a Mn-oxide suitable for 40Ar-39Ar dating. The ages obtained document major weathering periods at ~ 53-50 Ma, ~ 40-32 Ma, and ~ 30-23 Ma in the highland profiles, and ~ 47-45 Ma, ~ 24-19 Ma and a younger age at ~ 9 Ma in the coastal lowland profiles. The age clusters are in good agreement with major regional and global Cenozoic paleoclimatic events, e.g., the Eocene climatic optimum and the early beginnings of Asian monsoons at ~ 40 Ma. The old ages obtained both in the coastal lowland and high plateau indicate synchronous lateritic (mostly bauxitic) weathering on both sides of the escarpment. The ages also indicate that most of the incision and dissection of plateau landsurfaces must have taken place during successive periods after 45, 32 and 23 Ma, while the coastal lowland surface was only weakly incised after 19 Ma. Our results thus document post-Eocene divergent erosion and weathering histories across the escarpment since it was formed at least 47 Ma ago, suggesting installation of a dual climatic regime on

  10. Silica- and sulfate-bearing rock coatings in smelter areas: Products of chemical weathering and atmospheric pollution I. Formation and mineralogical composition

    NASA Astrophysics Data System (ADS)

    Mantha, Nathalie M.; Schindler, Michael; Murayama, Mitsuhiro; Hochella, Michael F.

    2012-05-01

    Black rock-coatings occur in proximity to smelters and roast yards of the Greater Sudbury area, Ontario, Canada and contain information about the past interactions between surface minerals, and gaseous and particulate atmospheric components, many of which were pollutants. Rock-coatings were collected from various locations within the Sudbury area and are characterized with scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electron microprobe analysis, infrared spectroscopy and X-ray photoelectron spectroscopy. Acidic fumigations and rain, the result of vast quantities of SO2 released from smelting, increased the chemical weathering rate of exposed rocks in the Sudbury area. Non-stoichiometric dissolution of the silicate minerals under acidic conditions resulted in the accumulation of silicic acid and the subsequent formation of a silica-gel type coating. The silica gel transformed overtime into amorphous silica, opal (opal C and opal-CT) and cristobalite. Dissolution of the underlying rock and also of metal-bearing particles by sulfuric acid resulted in the in situ formation of metal-sulfate-rich layers on the interfaces between the atmosphere and the silica-rich coating (atmosphere-coating interface, ACI) and between the silica-rich coating and the underlying rock (rock-coating interface, RCI). These metal-sulfate-rich layers contain nanometer aggregates of Fe-Cu-sulfate-hydroxide, goldichite, mereiterite, guildite, butlerite and antlerite. The silica-rich matrix also contains a mix of detrital grains from adjacent rocks and soils (feldspar, quartz, hematite, chlorite, montmorillonite) and non-dissolved smelter-derived nano- to micro-size particulates (metal-silicates, metal-oxides, C-spheres). The apparent disequilibrium between the embedded particles and the Fe-Cu-sulfates suggests that trapped nanoparticles were encapsulated into pores which prevented their equilibration with acidic metal-sulfate-bearing fluids. An XPS depth

  11. Space Weathering of Apollo 16 Sample 62255: Lunar Rocks as Witness Plates for Deciphering Regolith Formation Processes

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; McKay, D. S.; Keller, L. P.

    2004-01-01

    Space weathering, or alteration that occurs at the surfaces of materials exposed directly to space, has been one of the primary areas of focus of lunar studies for the past several years. It is caused by processes such as micrometeorite impacts and solar wind bombardment, and effects can include microcraters, spall zones, and vapor deposits. Much of the recent work on space weathering has been concentrated on nanoscale features, especially the amorphous rims commonly found on individual lunar soil grains. The rims typically contain nanophase Fe metal globules, which, along with Fe metal globules in agglutinates, have a profound effect on optical properties of lunar soils. The nanophase metallic iron globules cause the characteristic optical changes (reddening and darkening) found in mature lunar soils.

  12. Critical zone co-evolution: evidence that weathering and consequent seasonal rock moisture storage leads to a mixed forest canopy of conifer and evergreen broadleaf trees

    NASA Astrophysics Data System (ADS)

    Oshun, J.; Dietrich, W. E.; Dawson, T. E.; Rempe, D. M.; Fung, I. Y.

    2014-12-01

    Despite recent studies demonstrating the importance of rock moisture as a source of water to vegetation, much remains unknown regarding species-specific and seasonal patterns of water uptake in a Mediterranean climate. Here, we use stable isotopes of water (d18O, dD) to define the isotope composition of water throughout the subsurface critical zone of Rivendell, within the Eel River Critical Zone Observatory. We find that a structured heterogeneity of water isotope composition exists in which bulk saprolite is chronically more negative than bulk soil, and tightly held moisture is more negative than the mobile water that recharges the saturated zone and generates runoff. These moisture reservoirs provide a blueprint from which to measure the seasonal uptake patterns of different species collocated on the site. Douglas-firs use unsaturated saprolite and weathered bedrock moisture (i. e. rock moisture) throughout the year. Contrastingly, hardwood species (madrone, live oak, tanoak) modify their source water depending on which moisture is energetically favorable. Hardwoods use freely mobile water in the wet season, and rely on unsaturated zone soil moisture in the dry season. When soil water tension decreases on the drier south-facing slope, hardwood species use saprolite moisture. Although adjacent hardwoods and Douglas-firs partition water based on matric pull on the north side, there is competition for saprolite moisture in late summer on the south side. These results reveal the eco-hydrological importance of moisture derived from weathered bedrock, and show that the hardwoods have a competitive advantage under the drier conditions predicted in many climate models. Finally, the data emphasize that isotope measurements of all subsurface reservoirs and potential water sources are necessary for a complete and accurate characterization of the eco-hydrological processes within the critical zone.

  13. Characteristics of chemical weathering and water-rock interaction in Lake Nyos dam (Cameroon): Implications for vulnerability to failure and re-enforcement

    NASA Astrophysics Data System (ADS)

    Fantong, Wilson Y.; Kamtchueng, Brice T.; Yamaguchi, Kohei; Ueda, Akira; Issa; Ntchantcho, Romaric; Wirmvem, Mengnjo J.; Kusakabe, Minoru; Ohba, Takeshi; Zhang, Jing; Aka, Festus T.; Tanyileke, Gregory; Hell, Joseph V.

    2015-01-01

    For the first time, comprehensive study of hydrogeochemistry of water seeps, role of chemical weathering on dam failure, estimation of minimum width of dam to resist failure and simulation of changes in dissolved ions and secondary mineral was conducted on the Lake Nyos dam. The salient results and conclusions were; the dam spring water represented a mixture of 60-70% rainwater and 30-40% Lake water (from 0 to -40 m). The chemistry of the observed waters was Ca-HCO3 for rainwater, Ca-Mg-HCO3 in boreholes, and Mg-Ca-HCO3- for spring water. The relative rate at which ions dissolved in water was HCO3- > Mg2+ > Ca2+ > Na+ > SiO2 > K+ > NO3- > SO42- > Cl-. Weathering of rocks resulted in the formation of clay minerals such as kaolinite and smectite. Relative mobility of elements compared to Alumina (Al2O3) indicated that in monzonites there was a loss of CaO, Na2O, K2O, P2O5 and gain of SiO2, Fe2O3, TiO2, MnO and MgO, while in basalts there was a loss of SiO2, Fe2O3, Ca2O, NaO, MgO and gain of TiO2, K2O and P2O5. Values of chemical alteration index that ranged from 49 to 82 suggest a weak to intermediate categories of chemical weathering that occurred at a rate of 5.7 mm/year. Paired to that rate, which suggests that the dam is not vulnerable to failure at the previously thought time scale, some other processes (physical weathering, secondary mineral formation and lake overflow) can cause instant failure. Hydrostatic pressure of 1.6 GN generated by Lake water can be supported only when the width of the dam is greater than 19 m. PHREEQC-based simulation for 10 years indicates decoupling of Ca and Mg, and Na and Mg. Multidisciplinary monitoring of the dam is advocated.

  14. Testing the limits of micro-scale analyses of Si stable isotopes by femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry with application to rock weathering

    NASA Astrophysics Data System (ADS)

    Schuessler, Jan A.; von Blanckenburg, Friedhelm

    2014-08-01

    An analytical protocol for accurate in-situ Si stable isotope analysis has been established on a new second-generation custom-built femtosecond laser ablation system. The laser was coupled to a multicollector inductively coupled plasma mass spectrometer (fsLA-MC-ICP-MS). We investigated the influence of laser parameters such as spot size, laser focussing, energy density and repetition rate, and ICP-MS operating conditions such as ICP mass load, spectral and non-spectral matrix effects, signal intensities, and data processing on precision and accuracy of Si isotope ratios. We found that stable and reproducible ICP conditions were obtained by using He as aerosol carrier gas mixed with Ar/H2O before entering the plasma. Precise δ29Si and δ30Si values (better than ± 0.23‰, 2SD) can be obtained if the area ablated is at least 50 × 50 μm; or, alternatively, for the analysis of geometric features down to the width of the laser spot (about 20 μm) if an equivalent area is covered. Larger areas can be analysed by rastering the laser beam, whereas small single spot analyses reduce the attainable precision of δ30Si to ca. ± 0.6‰, 2SD, for < 30 μm diameter spots. It was found that focussing the laser beam beneath the sample surface with energy densities between 1 and 3.8 J/cm2 yields optimal analytical conditions for all materials investigated here. Using pure quartz (NIST 8546 aka. NBS-28) as measurement standard for calibration (standard-sample-bracketing) did result in accurate and precise data of international reference materials and samples covering a wide range in chemical compositions (Si single crystal IRMM-017, basaltic glasses KL2-G, BHVO-2G and BHVO-2, andesitic glass ML3B-G, rhyolitic glass ATHO-G, diopside glass JER, soda-lime glasses NIST SRM 612 and 610, San Carlos olivine). No composition-dependent matrix effect was discernible within uncertainties of the method. The method was applied to investigate the Si isotope signature of rock weathering at

  15. Linking Weathering, Rock Moisture Dynamics, Geochemistry, Runoff, Vegetation and Atmospheric Processes through the Critical Zone: Graduate Student led Research at the Eel River Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Dietrich, W. E.

    2014-12-01

    In the Eel River Critical Zone Observatory lies Rivendell, a heavily-instrumented steep forested hillslope underlain by nearly vertically dipping argillite interbedded with sandstone. Under this convex hillslope lies "Zb", the transition to fresh bedrock, which varies from less than 6 m below the surface near the channel to 20 m at the divide. Rempe and Dietrich (2014, PNAS) show that the Zb profile can be predicted from the assumption that weathering occurs when drainage is induced in the uplifting fresh bedrock under hillslopes by lateral head gradients driven by channel incision at the hillslope boundary. Infiltrating winter precipitation is impeded at the lower conductivity boundary at Zb, generating perched groundwater that dynamically pulses water laterally to the channel, controlling stream runoff. Below the soil and above the water table lies an unsaturated zone through which all recharge to the perched groundwater (and thus all runoff to channels) occurs. It is this zone and the waters in them that profoundly affect critical zone processes. In our seasonally dry environment, the first rains penetrate past the soil and moisten the underlying weathered bedrock (Salve et al., 2012, WRR). It takes about 200 to 400 mm of cumulative rain, however, before the underlying groundwater rises significantly. Oshun et al (in review) show that by this cumulative rainfall the average of the wide-ranging isotopic signature of rain reaches a nearly constant average annual value. Consequently, the recharging perched groundwater shows only minor temporal isotopic variation. Kim et al, (2014, GCA) find that the winter high-flow groundwater chemistry is controlled by relatively fast-reacting cation exchange processes, likely occurring in transit in the unsaturated zone. Oshun also demonstrates that the Douglas fir rely on this rock moisture as a water source, while the broadleaf trees (oaks and madrone) use mostly soil moisture. Link et al (2014 WRR) show that Doug fir declines

  16. Impact of weathering on the geomechanical properties of rocks along thermal metamorphic contact belts and morpho-evolutionary processes: The deep-seated gravitational slope deformations of Mt. Granieri Salincriti (Calabria Italy)

    NASA Astrophysics Data System (ADS)

    Pellegrino, A.; Prestininzi, A.

    2007-06-01

    Numerous Deep-Seated Gravitational Slope Deformations (DSGSDs) occur throughout Italy, that originate from particular tectono-stratigraphic settings, relief, seismicity, deglaciation, as well as from intense and deep processes of chemico-physical weathering of crystalline-metamorphic rocks. These DSGSDs are particularly widespread in the Calabrian mountains. This study is focused on the Mt. Granieri-Salincriti slope, on the Ionian side of the Serre Massif, where granites and granodiorites (Stilo Unit, Palaeozoic) are in contact with metamorphites through a thermal-metamorphic aureole. This setting generates deep geochemical processes, inducing intense chemical weathering. These processes are mainly due to the interaction between groundwater and the sulphides that are contained in the local pegmatitic-hydrothermal intrusions, especially along the thermal-metamorphic contact belt. The Mt. Granieri-Salincriti slope has an important DSGSD, which is associated with many active and/or quiescent landslides. Among these landslides, the Salincriti rock avalanche-debris flow (about 2 M m 3) represents the paroxysmal and terminal stage of the deep creep deformations of Mt. Granieri, typifying a geological setting that is common in the Calabrian Arc. This multi-disciplinary study assessed the weathering susceptibility of the local crystalline-metamorphic rocks, especially those lying along thermal-metamorphic contact belts, by characterising the weathering horizons and the spatial distribution of weathering in the rock mass. The study was also aimed at identifying the relations between weathering, above all deep geochemical processes, effects on rocks and slope morphodynamics. The methodology was based on detailed geological data, geological-engineering surveys, geomorphology and surface hydrogeology analyses, as well as physico-mechanical laboratory tests. These investigations, supported by a monitoring program, led to the development of an engineering-geological model of the

  17. FTIR Spectra of Possible End Products of Martian Surface Weathering

    NASA Astrophysics Data System (ADS)

    Maxe, L. P.

    2008-03-01

    Comparative analysis of IR spectra shows that martian weathering can lead to separating destruction of surface rocks. The semi-cosmic martian weathering results in amorphous silica dust and open unique ferry aluminum/ferry silicate martian rocks.

  18. Os-Ru-Ir and Os-(Ru)-Ir-Pt mineral phases from iron quartzites and weathered rocks of the Mikhailovka and Staryi Oskol KMA iron regions, central Russia

    NASA Astrophysics Data System (ADS)

    Chernyshov, N. M.; Ponamareva, M. M.

    2015-02-01

    Numerous natural Os-Ir-Ru and Os-Ir-Ru-Pt alloys have been found in iron quartzites and their weathered rocks. The Ir-Os alloys in the Mikhailovka and Staryi Oskol KMA iron regions are characterized by the densest hexagonal packing. Almost all of them contain a low amount of Fe and Ni at a relatively higher amount of Pt, Ru, and, locally, Rh. The highest Rh contents are typical of minerals with Ir dominant over Os or with a high Pt content.

  19. Groundwater flow dynamics of weathered hard-rock aquifers under climate-change conditions: an illustrative example of numerical modeling through the equivalent porous media approach in the north-western Pyrenees (France)

    NASA Astrophysics Data System (ADS)

    Jaunat, J.; Dupuy, A.; Huneau, F.; Celle-Jeanton, H.; Le Coustumer, P.

    2016-04-01

    A numerical groundwater model of the weathered crystalline aquifer of Ursuya (a major water source for the north-western Pyrenees region, south-western France) has been computed based on monitoring of hydrological, hydrodynamic and meteorological parameters over 3 years. The equivalent porous media model was used to simulate groundwater flow in the different layers of the weathered profile: from surface to depth, the weathered layer (5 · 10-8 ≤ K ≤ 5 · 10-7 m s-1), the transition layer (7 · 10-8 ≤ K ≤ 1 · 10-5 m s-1, the highest values being along major discontinuities), two fissured layers (3.5 · 10-8 ≤ K ≤ 5 · 10-4 m s-1, depending on weathering profile conditions and on the existence of active fractures), and the hard-rock basement simulated with a negligible hydraulic conductivity (K = 1 10 -9 ). Hydrodynamic properties of these five calculation layers demonstrate both the impact of the weathering degree and of the discontinuities on the groundwater flow. The great agreement between simulated and observed hydraulic conditions allowed for validation of the methodology and its proposed use for application on analogous aquifers. With the aim of long-term management of this strategic aquifer, the model was then used to evaluate the impact of climate change on the groundwater resource. The simulations performed according to the most pessimistic climatic scenario until 2050 show a low sensitivity of the aquifer. The decreasing trend of the natural discharge is estimated at about -360 m3 y-1 for recharge decreasing at about -5.6 mm y-1 (0.8 % of annual recharge).

  20. Weather Watch

    ERIC Educational Resources Information Center

    Bratt, Herschell Marvin

    1973-01-01

    Suggests a number of ways in which Federal Aviation Agency weather report printouts can be used in teaching the weather section of meteorology. These weather sequence reports can be obtained free of charge at most major airports. (JR)

  1. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This article deals with a poster entitled, "Severe Weather," that has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in…

  2. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This month's insert, Severe Weather, has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in this poster are hurricanes,…

  3. Weather & Weather Maps. Teacher's Manual.

    ERIC Educational Resources Information Center

    Metro, Peter M.; Green, Rachel E.

    This guide is intended to provide an opportunity for students to work with weather symbols used for reporting weather. Also included are exercises in location of United States cities by latitude and longitude, measurement of distances in miles and kilometers, and prediction of weather associated with various types of weather fronts. (RE)

  4. Weathering and weathering rates of natural stone

    SciTech Connect

    Winkler, E.M. )

    1987-01-01

    Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the ricks permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of th causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between dissolution, crack-corrosion, and the expansion-contraction cycles triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

  5. Soil Genesis and Development, Lesson 1 - Rocks and Minerals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All soil ultimately forms from rocks or their weathering products. Geologists classify rocks according to their origins. General rock types can weather to give soils with distinctive properties. The objectives of this lesson are: 1. To be able to classify rocks based on visual characteristics accord...

  6. Carbon dioxide efficiency of terrestrial enhanced weathering.

    PubMed

    Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

    2014-05-01

    Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance. PMID:24597739

  7. Weather Instruments.

    ERIC Educational Resources Information Center

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities to measure various weather phenomena. Directions for constructing a weather station are included. Instruments including rain gauges, thermometers, wind vanes, wind speed devices, humidity devices, barometers, atmospheric observations, a dustfall jar, sticky-tape can, detection of gases in the air, and pH of…

  8. Wacky Weather

    ERIC Educational Resources Information Center

    Sabarre, Amy; Gulino, Jacqueline

    2013-01-01

    What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

  9. Space Weather

    NASA Technical Reports Server (NTRS)

    Gallagher, Dennis L.

    2010-01-01

    This video provides a narrated exploration of the history and affects of space weather. It includes information the earth's magnetic field, solar radiation, magnetic storms, and how solar winds affect electronics on earth, with specific information on how space weather affects space exploration in the future.

  10. Natural Weathering Rates of Silicate Minerals

    NASA Astrophysics Data System (ADS)

    White, A. F.

    2003-12-01

    Silicates constitute more than 90% of the rocks exposed at Earth's land surface (Garrels and Mackenzie, 1971). Most primary minerals comprising these rocks are thermodynamically unstable at surface pressure/temperature conditions and are therefore susceptible to chemical weathering. Such weathering has long been of interest in the natural sciences. Hartt (1853) correctly attributed chemical weathering to "the efficacy of water containing carbonic acid in promoting the decomposition of igneous rocks." Antecedent to the recent interest in the role of vegetation on chemical weathering, Belt (1874) observed that the most intense weathering of rocks in tropical Nicaragua was confined to forested regions. He attributed this effect to "the percolation through rocks of rain water charged with a little acid from decomposing vegetation." Chamberlin (1899) proposed that the enhanced rates of chemical weathering associated with major mountain building episodes in Earth's history resulted in a drawdown of atmospheric CO2 that led to periods of global cooling. Many of the major characteristics of chemical weathering had been described when Merrill (1906) published the groundbreaking volume Rocks, Rock Weathering, and Soils.The major advances since that time, particularly during the last several decades, have centered on understanding the fundamental chemical, hydrologic, and biologic processes that control weathering and in establishing quantitative weathering rates. This research has been driven by the importance of chemical weathering to a number environmentally and economically important issues. Undoubtedly, the most significant aspect of chemical weathering is the breakdown of rocks to form soils, a process that makes life possible on the surface of the Earth. The availability of many soil macronutrients such as magnesium, calcium, potassium, and PO4 is directly related to the rate at which primary minerals weather. Often such nutrient balances are upset by anthropogenic

  11. Three classes of Martian rocks

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this portion of the 360-degree color gallery pan, looking to the northeast, the colors have been exaggerated to highlight the differences between rocks and soils. Visible are the downwind sides of rocks, not exposed to wind scouring like Barnacle Bill (which faces upwind). There is a close correspondence between the shapes and colors of the rocks. Three general classes of rocks are recognized: large rounded rocks with weathered coatings, small gray angular rocks lacking weathered coatings, and flat white rocks. The large rounded rocks in the distance, marked by the red arrows, are comparable to Yogi. Spectral properties show that these rocks have a highly weathered coating in addition to a distinctive shape. A second population of smaller, angular rocks (blue arrows) in the foreground have unweathered surfaces even on the downwind side, except where covered on their tops by drift. These are comparable to Barnacle Bill. They may have been emplaced at the site relatively recently, perhaps as ejecta from an impact crater, so they have not had time to weather as extensively as the larger older rocks. The third kind of rock (white arrows) is white and flat, and includes Scooby Doo in the foreground and a large deposit in the background called Baker's Bank. The age of the white rock relative to the other two classes is still being debated. One representative rock of each class (Yogi, Barnacle Bill, and Scooby Doo) has been measured by the rover.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  12. Weatherizing America

    ScienceCinema

    Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony;

    2013-05-29

    As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

  13. Weatherizing America

    SciTech Connect

    Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony

    2009-01-01

    As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

  14. Temperature dependence of basalt weathering

    NASA Astrophysics Data System (ADS)

    Li, Gaojun; Hartmann, Jens; Derry, Louis A.; West, A. Joshua; You, Chen-Feng; Long, Xiaoyong; Zhan, Tao; Li, Laifeng; Li, Gen; Qiu, Wenhong; Li, Tao; Liu, Lianwen; Chen, Yang; Ji, Junfeng; Zhao, Liang; Chen, Jun

    2016-06-01

    The homeostatic balance of Earth's long-term carbon cycle and the equable state of Earth's climate are maintained by negative feedbacks between the levels of atmospheric CO2 and the chemical weathering rate of silicate rocks. Though clearly demonstrated by well-controlled laboratory dissolution experiments, the temperature dependence of silicate weathering rates, hypothesized to play a central role in these weathering feedbacks, has been difficult to quantify clearly in natural settings at landscape scale. By compiling data from basaltic catchments worldwide and considering only inactive volcanic fields (IVFs), here we show that the rate of CO2 consumption associated with the weathering of basaltic rocks is strongly correlated with mean annual temperature (MAT) as predicted by chemical kinetics. Relations between temperature and CO2 consumption rate for active volcanic fields (AVFs) are complicated by other factors such as eruption age, hydrothermal activity, and hydrological complexities. On the basis of this updated data compilation we are not able to distinguish whether or not there is a significant runoff control on basalt weathering rates. Nonetheless, the simple temperature control as observed in this global dataset implies that basalt weathering could be an effective mechanism for Earth to modulate long-term carbon cycle perturbations.

  15. Where fast weathering creates thin regolith and slow weathering creates thick regolith

    SciTech Connect

    Bazilevskaya, Ekaterina; Lebedeva, Marina; Pavich, Milan; Rother, Gernot; Parkinson, D. Y.; Cole, David; Brantley, S. L.

    2012-01-01

    Weathering disaggregates rock into regolith the fractured or granular earthmaterial that sustains life on the continental land surface. Here, we investigate what controls the depth of regolith formed on ridges of two rock compositions with similar initial porosities in Virginia (USA).A priori, we predicted that the regolith on diabasewould be thicker than on granite because the dominant mineral (feldspar) in the diabase weathers faster than its granitic counterpart. However, weathering advanced 20deeper into the granite than the diabase. The 20-thicker regolith is attributed mainly to connected micron-sized pores, microfractures formed around oxidizing biotite at 20m depth, and the lower iron (Fe) content in the felsic rock. Such porosity allows pervasive advection and deep oxidation in the granite. These observations may explainwhy regolithworldwide is thicker on felsic compared tomafic rock under similar conditions. To understand regolith formationwill require better understanding of such deep oxidation reactions and how they impact fluid flow during weathering.

  16. Tithonium Chasma's Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-565, 5 December 2003

    Exposures of light-toned, layered, sedimentary rocks are common in the deep troughs of the Valles Marineris system. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from western Tithonium Chasma. The banding seen here is an eroded expression of layered rock. Sedimentary rocks can be composed of (1) the detritus of older, eroded and weathered rocks, (2) grains produced by explosive volcanism (tephra, also known as volcanic ash), or (3) minerals that were chemically precipitated out of a body of liquid such as water. These outcrops are located near 4.8oS, 89.7oW. The image covers an area 3 km (1.9 mi) wide and is illuminated from the lower left.

  17. Weather control

    SciTech Connect

    Leepson, M.

    1980-09-05

    Weather modification, the intentional altering of atmospheric conditions to suit the purposes of humankind, has five basic forms: (1) fog dissipation; (2) rain and snow enhancement; (3) hail suppression; (4) lightning suppression; and (5) the abatement of severe storms such as hurricanes and tornadoes. The dissipation of fog and the seeding of clouds with dry ice or silver iodide to produce rain are the most successful weather modification techniques. Both are used extensively and with varying degrees of success in the United States and around the world. Cloud seeding, though, is not effective in easing the harshness of a drought, such as the one that hit the Southwest, Midwest and Great Plains this summer.

  18. Talking Rocks.

    ERIC Educational Resources Information Center

    Rice, Dale; Corley, Brenda

    1987-01-01

    Discusses some of the ways that rocks can be used to enhance children's creativity and their interest in science. Suggests the creation of a dramatic production involving rocks. Includes basic information on sedimentary, igneous, and metamorphic rocks. (TW)

  19. National Weather Service

    MedlinePlus

    ... Lightning Safe Boating Rip Currents Thunderstorms and Tornadoes Space Weather Sun (Ultraviolet Radiation) Safety Campaigns Wind Drought ... Outlook Hurricanes Fire Weather Outlooks UV Alerts Drought Space Weather NOAA Weather Radio NWS CAP Feeds PAST ...

  20. Weathering: methods and techniques to measure

    NASA Astrophysics Data System (ADS)

    Lopez-Arce, P.; Zornoza-Indart, A.; Alvarez de Buergo, M.; Fort, R.

    2012-04-01

    Surface recession takes place when weathered material is removed from the rocks. In order to know how fast does weathering and erosion occur, a review of several methods, analyses and destructive and non-destructive techniques to measure weathering of rocks caused by physico-chemical changes that occur in bedrocks due to salt crystallization, freezing-thaw, thermal shock, influence of water, wind, temperature or any type of environmental agent leading to weathering processes and development of soils, in-situ in the field or through experimental works in the laboratory are addressed. From micro-scale to macro-scale, from the surface down to more in depth, several case studies on in-situ monitoring of quantification of decay on soils and rocks from natural landscapes (mountains, cliffs, caves, etc) or from urban environment (foundations or facades of buildings, retaining walls, etc) or laboratory experimental works, such as artificial accelerated ageing tests (a.a.e.e.) or durability tests -in which one or more than one weathering agents are selected to assess the material behaviour in time and in a cyclic way- performed on specimens of these materials are summarised. Discoloration, structural alteration, precipitation of weathering products (mass transfer), and surface recession (mass loss) are all products of weathering processes. Destructive (SEM-EDX, optical microscopy, mercury intrusion porosimetry, drilling resistance measurement, flexural and compression strength) and Non-destructive (spectrophotocolorimetry, 3D optical surface roughness, Schmidt hammer rebound tester, ultrasound velocity propagation, Nuclear Magnetic Resonance NMR, X ray computed micro-tomography or CT-scan, geo-radar differential global positioning systems) techniques and characterization analyses (e.g. water absorption, permeability, open porosity or porosity accessible to water) to assess their morphological, physico-chemical, mechanical and hydric weathering; consolidation products or

  1. Lateral Variations in Lunar Weathering Patina on Centimeter to Nanometer Scales

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2013-01-01

    All materials exposed at the lunar surface undergo space weathering processes. On the Moon, boulders make up only a small percentage of the exposed surface, and areas where such rocks are exposed, like central peaks, are often among the least space weathered regions identified from remote sensing data. Yet space weathered surfaces (patina) are relatively common on returned rock samples, some of which directly sample the surface of larger boulders. Because, as witness plates to lunar space weathering, rocks and boulders experience longer exposure times compared to lunar soil grains, they allow us to develop a deeper perspective on the relative importance of various weathering processes as a function of time.

  2. Weathering of Stone Monuments in Cities: A Student Exercise.

    ERIC Educational Resources Information Center

    Dragovich, D.

    1980-01-01

    Describes a college-level geography project for students limited to urban areas. Students investigate the rock-weathering process through library resources, then observe, collect, and analyze data about stone monuments. An individually written report concludes the project. (KC)

  3. Weather in the News.

    ERIC Educational Resources Information Center

    Markle, Sandra

    1989-01-01

    A discussion of TV weather forecasting introduces this article which features several hands-on science activities involving observing, researching, and experimenting with the weather. A reproducible worksheet on the reliability of weather forecasts is included. (IAH)

  4. Winter Weather Checklists

    MedlinePlus

    ... Planning Information on Specific Types of Emergencies Winter Weather Checklists Language: English Español (Spanish) Recommend on Facebook ... emergency instructions National Oceanic and Atmospheric Administration (NOAA) weather radio receiver for listening to National Weather Service ...

  5. Forecasting the Weather.

    ERIC Educational Resources Information Center

    Bollinger, Richard

    1984-01-01

    Presents a computer program which predicts the weather based on student input of such weather data as wind direction and barometric pressure. Also provides procedures for several hands-on, weather-related activities. (JN)

  6. Rock Art

    ERIC Educational Resources Information Center

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  7. Rock Finding

    ERIC Educational Resources Information Center

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  8. Collecting Rocks.

    ERIC Educational Resources Information Center

    Barker, Rachel M.

    One of a series of general interest publications on science topics, the booklet provides those interested in rock collecting with a nontechnical introduction to the subject. Following a section examining the nature and formation of igneous, sedimentary, and metamorphic rocks, the booklet gives suggestions for starting a rock collection and using…

  9. Rock Pore Structure as Main Reason of Rock Deterioration

    NASA Astrophysics Data System (ADS)

    Ondrášik, Martin; Kopecký, Miloslav

    2014-03-01

    Crashed or dimensional rocks have been used as natural construction material, decoration stone or as material for artistic sculptures. Especially old historical towns not only in Slovakia have had experiences with use of stones for construction purposes for centuries. The whole buildings were made from dimensional stone, like sandstone, limestone or rhyolite. Pavements were made especially from basalt, andesite, rhyolite or granite. Also the most common modern construction material - concrete includes large amounts of crashed rock, especially limestone, dolostone and andesite. However, rock as any other material if exposed to exogenous processes starts to deteriorate. Especially mechanical weathering can be very intensive if rock with unsuitable rock properties is used. For long it had been believed that repeated freezing and thawing in relation to high absorption is the main reason of the rock deterioration. In Slovakia for many years the high water absorption was set as exclusion criterion for use of rocks and stones in building industry. Only after 1989 the absorption was accepted as merely informational rock property and not exclusion. The reason of the change was not the understanding of the relationship between the porosity and rock deterioration, but more or less good experiences with some high porous rocks used in constructions exposed to severe weather conditions and proving a lack of relationship between rock freeze-thaw resistivity and water absorption. Results of the recent worldwide research suggest that understanding a resistivity of rocks against deterioration is hidden not in the absorption but in the structure of rock pores in relation to thermodynamic properties of pore water and tensile strength of rocks and rock minerals. Also this article presents some results of research on rock deterioration and pore structure performed on 88 rock samples. The results divide the rocks tested into two groups - group N in which the pore water does not freeze

  10. Soil Genesis and Development, Lesson 2 - Processes of Weathering

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weathering processes — which include physical, chemical, and biological — contribute to the development of soil. The learning objectives of the lesson are: 1) Define and distinguish physical, chemical, and biological weathering processes; and 2) Describe how rock and mineral properties and environm...

  11. Correlation of Rock Spectra with Quantitative Morphologic Indices: Evidence for a Single Rock Type at the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Yingst, R. A.; Biedermann, K. L.; Pierre, N. M.; Haldemann, A. F. C.; Johnson, J. R.

    2005-01-01

    The Mars Pathfinder (MPF) landing site was predicted to contain a broad sampling of rock types varying in mineralogical, physical, mechanical and geochemical characteristics. Although rocks have been divided into several spectral categories based on Imager for Mars Pathfinder (IMP) visible/near-infrared data, efforts in isolating and classifying spectral units among MPF rocks and soils have met with varying degrees of success, as many factors influencing spectral signatures cannot be quantified to a sufficient level to be removed. It has not been fully determined which spectral categories stem from intrinsic mineralogical differences between rocks or rock surfaces, and which result from factors such as physical or chemical weathering. This has made isolation of unique rock mineralogies difficult. Morphology, like composition, is a characteristic tied to the intrinsic properties and geologic and weathering history of rocks. Rock morphologies can be assessed quantitatively and compared with spectral data, to identify and classify rock types at the MPF landing site. They can also isolate actual rock spectra from spectral types that are surficial in origin, as compositions associated with mantling dust or chemical coatings would presumably not influence rock morphology during weathering events. We previously reported on an initial classification of rocks using the quantitative morphologic indices of size, roundness, sphericity and elongation. Here, we compare this database of rock characteristics with associated rock surface spectra to improve our ability to discriminate between spectra associated with rock types and those from other sources.

  12. What Solutions Caused Noachian Weathering on Mars?

    NASA Astrophysics Data System (ADS)

    Zolotov, M. Y.

    2015-12-01

    The stratified sequence of Al-rich and Fe/Mg phyllosilicates in Noachian formations indicates widespread chemical weathering of mafic materials [1]. The composition of alteration solutions could be inferred from the mineralogy of weathering profiles and models for water-rock interaction. We have developed numerical models for basalt weathering by acidic solutions with different concentrations of weak (H2CO3) and strong (H2SO4, HCl) acids equilibrated with low- and high-pressure CO2 atmospheres. The results show that the observed clay stratigraphies could be produced by neutral to strongly acidic solutions. Weathering by solutions equilibrated with dense CO2 atmospheres produces abundant carbonates at depth, which are not observed in clay stratigraphies. The development of weathering profiles by S-, Cl-free solutions equilibrated with 6 mbar CO2 requires large volumes of water. These volumes are inconsistent with density and orientation of Noachian valley networks and climate models [3-5]. Weathering by sulfate-free fluids does not produce abundant Ca sulfates reported in the Mawrth Valley region [2]. Weathering by low-pH H2SO4-bearing solutions does not require elevated water/rock ratios, a warm climate, or a dense CO2 atmosphere. It leads to formation of Ca sulfates in middle parts of weathering profiles together with neutralized Mg-rich sulfate solutions at depth. The weathering could have occurred through transient volcanism- and impact-generated supply of strong acids, and volcanism-, impact-, obliquity-related warming and partial ice melting, consistent with climate models [3-5]. Refs: [1] Carter, J. et al. (2015), Icarus 248, 373-382. [2] Wray, J. J. et al. (2010), Icarus 209, 416-421. [3] Wordsworth, R. et al. (2013), Icarus 222, 1-19. [4] Mischna, M. A. et al. (2013), J. Geophys. Res. Planets 118, 518-576. [5] Halevy, I., Head, J.W. (2014), Nature Geosci. 7, 865-868.

  13. Weather in Your Life.

    ERIC Educational Resources Information Center

    Kannegieter, Sandy; Wirkler, Linda

    Facts and activities related to weather and meteorology are presented in this unit. Separate sections cover the following topics: (1) the water cycle; (2) clouds; (3) the Beaufort Scale for rating the speed and force of wind; (4) the barometer; (5) weather prediction; (6) fall weather in Iowa (sleet, frost, and fog); (7) winter weather in Iowa…

  14. Fun with Weather

    ERIC Educational Resources Information Center

    Yildirim, Rana

    2007-01-01

    This three-part weather-themed lesson for young learners connects weather, clothing, and feelings vocabulary. The target structures covered are: asking about the weather; comparing weather; using the modal auxiliary, should; and the question word, when. The lessons utilize all four skills and include such activities as going outside, singing,…

  15. Teaching Weather Concepts.

    ERIC Educational Resources Information Center

    Sebastian, Glenn R.

    Ten exercises based on the weather map provided in the national newspaper "U.S.A. Today" are used to teach intermediate grade students about weather. An overview describes the history of "U.S.A. Today," the format of the newspaper's weather map, and the map's suitability for teaching weather concepts. Specific exercises, which are briefly…

  16. The role of basalt weathering on climate: the Siberian traps

    NASA Astrophysics Data System (ADS)

    Grard, A.; François, L.; Dessert, C.; Dupré, B.; Goddéris, Y.

    2003-04-01

    The Siberian traps represent one of the most important flood basalt provinces on Earth. Their onset coincides with a profound faunal mass extinction at the Permo-Trias boundary (250 my ago). The volcanic eruption has also environmental and climatic effects through aerosols and gases injection into the atmosphere. Chemical weathering processes play a major role in biogeochemical cycles and climate evolution. In particular, the weathering of silicate rocks represents an important sink of atmospheric CO_2. At the million-year timescale, the volcanic release of CO_2 into the atmosphere-ocean system is balanced by its consumption during silicate weathering followed by carbonate deposition on the seafloor. Recent data have shown that chemical weathering of basalt is five to ten times more efficient than weathering of acidic silicate rocks such as granite or gneiss (Dessert et al., EPSL, 188 : 459-474, 2001). Thus the weathering of basaltic rocks consumes more atmospheric CO_2 than other silicate rocks. In the case of subaerial basaltic volcanism, an eruption not only releases CO_2 to the atmosphere, but also produces basaltic rocks which weather rapidly, enhancing CO_2 consumption rates. Currently, the Siberian basaltic traps are located in a cold and dry region. The weathering rates of this province are low, and the climatic impact is thus currently low. But in the past, the latitudinal temperature gradient was smaller. During the Permian, the climate was significantly warmer than today. Thus the chemical weathering of the Siberian traps was enhanced at that time, and this process led to a long-term impact on the Triassic climate and on the carbon cycle. The used model calculates the traps impact on the long-term carbon cycle and climate evolution. This model has been refined and adapted to high latitudes environments. We quantify the cooling caused by traps weathering.

  17. 'Earhart' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock informally named 'Earhart' on the lower slopes of 'Endurance Crater.' The rock was named after the pilot Amelia Earhart. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe fractures in Earhart could have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Rover team members do not have plans to investigate Earhart in detail because it is located across potentially hazardous sandy terrain. This image was taken on sol 219 (Sept. 4) by the rover's panoramic camera, using its 750-, 530- and 430-nanometer filters.

  18. Landslides as weathering reactors; links between physical erosion and weathering in rapidly eroding mountain belts

    NASA Astrophysics Data System (ADS)

    Emberson, R.; Hovius, N.; Galy, A.

    2014-12-01

    The link between physical erosion and chemical weathering is generally modelled with a surface-blanketing weathering zone, where the supply of fresh minerals is tied to the average rate of denudation. In very fast eroding environments, however, sediment production is dominated by landsliding, which acts in a stochastic fashion across the landscape, contrasting strongly with more uniform denudation models. If physical erosion is a driver of weathering at the highest erosion rates, then an alternative weathering model is required. Here we show that landslides can be effective 'weathering reactors'. Previous work modelling the effect of landslides on chemical weathering (Gabet 2007) considered the fresh bedrock surfaces exposed in landslide scars. However, fracturing during the landslide motion generates fresh surfaces, the total surface area of which exceeds that of the exposed scar by many orders of magnitude. Moreover, landslides introduce concavity into hillslopes, which acts to catch precipitation. This is funnelled into a deposit of highly fragmented rock mass with large reactive surface area and limited hydraulic conductivity (Lo et al. 2007). This allows percolating water reaction time for chemical weathering; any admixture of macerated organic debris could yield organic acid to further accelerate weathering. In the South island of New Zealand, seepage from recent landslide deposits has systematically high solute concentrations, far outstripping concentration in runoff from locations where soils are present. River total dissolved load in the western Southern Alps is highly correlated with the rate of recent (<35yrs) landsliding, suggesting that landslides are the dominant locus of weathering in this rapidly eroding landscape. A tight link between landsliding and weathering implies that localized weathering migrates through the landscape with physical erosion; this contrasts with persistent and ubiquitous weathering associated with soil production. Solute

  19. Science Rocks!

    ERIC Educational Resources Information Center

    Prestwich, Dorothy; Sumrall, Joseph; Chessin, Debby A.

    2010-01-01

    It all began one Monday morning. Raymond could not wait to come to large group. In his hand, he held a chunk of white granite he had found. "Look at my beautiful rock!" he cried. The rock was passed around and examined by each student. "I wonder how rocks are made?" wondered one student. "Where do they come from?" asked another. At this moment, a…

  20. Constraints on the Global-scale Chemical Weathering State of Mars From TES Results Based on Spectral Analysis of Chemically Weathered Basalts

    NASA Astrophysics Data System (ADS)

    Michalski, J. R.; Kraft, M. D.; Sharp, T. G.; Christensen, P. R.

    2005-12-01

    On Earth, subaerially exposed basaltic rocks (from arid-to-tropical regions) develop weathering rinds and rock coatings that affect spectroscopic measurements of their natural surfaces. Similarly, basaltic rocks and basaltic soil particles on Mars may have rinds and coatings that are spectroscopically observable. Thermal emission spectroscopy, because it provides information about the composition and structure of silicate and non-silicate minerals and mineraloids, provides a useful perspective on the mineralogy of weathered surfaces; reconciliation of the emission spectral features of weathered surfaces with observations from other datasets is critical to interpretations of thermal emission spectral features of Mars. In this study, we investigate the thermal emission (6-25 μm) and visible/near-infrared (VNIR) (0.4-2.5 μm) spectroscopic features of fresh and weathered surfaces of rock samples from the Columbia River Basalt Group (CRBG). VNIR spectra of weathered rock surfaces are brighter and redder than fresh rock surfaces, but contain no evidence for neoformation of clay minerals within subaerially exposed, weathered surfaces. In contrast, thermal emission spectroscopy suggests an enrichment of clay minerals in weathered surfaces. Also, thermal emission spectroscopy indicates the presence of glass-like materials in many weathered surfaces, which likely correspond to amorphous weathering products present within fractures, as coatings on minerals, or as coatings on the rocks themselves. These results have important implications for interpretation of TES and THEMIS data of Mars, including: 1) glasses and clays detected on Mars from thermal infrared spectra may correspond to poorly crystalline weathering products within chemically weathered rock surfaces, 2) chemically weathered surfaces of basalts may appear oxidized but clay-poor to VNIR datasets, and 3) the differential chemical breakdown of primary phases can affect interpretations of the remaining primary rock

  1. Rock flows

    NASA Technical Reports Server (NTRS)

    Matveyev, S. N.

    1986-01-01

    Rock flows are defined as forms of spontaneous mass movements, commonly found in mountainous countries, which have been studied very little. The article considers formations known as rock rivers, rock flows, boulder flows, boulder stria, gravel flows, rock seas, and rubble seas. It describes their genesis as seen from their morphological characteristics and presents a classification of these forms. This classification is based on the difference in the genesis of the rubbly matter and characterizes these forms of mass movement according to their source, drainage, and deposit areas.

  2. Pilot weather advisor

    NASA Technical Reports Server (NTRS)

    Kilgore, W. A.; Seth, S.; Crabill, N. L.; Shipley, S. T.; Graffman, I.; Oneill, J.

    1992-01-01

    The results of the work performed by ViGYAN, Inc., to demonstrate the Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication system are presented. The Pilot Weather Advisor demonstrated that the technical problems involved with transmitting significant amount of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The Pilot Weather Advisor appears to be a viable solution for providing accurate and timely weather information for general aviation aircraft.

  3. Weather Information System

    NASA Technical Reports Server (NTRS)

    1995-01-01

    WxLink is an aviation weather system based on advanced airborne sensors, precise positioning available from the satellite-based Global Positioning System, cockpit graphics and a low-cost datalink. It is a two-way system that uplinks weather information to the aircraft and downlinks automatic pilot reports of weather conditions aloft. Manufactured by ARNAV Systems, Inc., the original technology came from Langley Research Center's cockpit weather information system, CWIN (Cockpit Weather INformation). The system creates radar maps of storms, lightning and reports of surface observations, offering improved safety, better weather monitoring and substantial fuel savings.

  4. Global chemical weathering and associated P-release

    NASA Astrophysics Data System (ADS)

    Hartmann, Jens; Moosdorf, Nils; Lauerwald, Ronny; Hinderer, Matthias; West, A. Joshua

    2014-05-01

    Chemical weathering releases phosphorus to soils and ecosystems. To improve understanding of the spatial distribution of the global P-release characteristics, a model framework for estimating global chemical weathering rates was coupled with geochemical information. Results suggest that the global soil shielding reduces chemical weathering fluxes by about 44%, compared to an Earth surface with no deeply weathered soils but relatively young rock surfaces (e.g. as in volcanic arc and other tectonically active areas). About 70% of the weathering fluxes globally derive from 10% of the land area, with Southeast Asia being a primary "hot spot" of chemical weathering and for P-release. In contrast, only 50% of runoff is attributed to 10% of the land area; thus the global chemical weathering rating curve is to some extent disconnected from the global runoff curve due to the spatially heterogeneous climate as well as differences in rock and soil properties. In addition to total chemical weathering fluxes, the release of P, a nutrient that controls biological productivity at large spatial scales, is affected by the spatial correlation between runoff, lithology, temperature and soil properties. The areal abundance of deeply weathered soils in Earth's past may have influenced weathering fluxes and P-fuelled biological productivity significantly, specifically in the case of larger climate shifts when high runoff fields shift to areas with thinner soils or areas with more weatherable rocks and relatively increased P-content. This observation may be particularly important for spatially resolved Earth system models targeting geological time scales. The full research text can be found in: Hartmann, J., N. Moosdorf, R. Lauerwald, M. Hinderer, A.J. West (2014) Global chemical weathering and associated P-release - the role of lithology, temperature and soil properties. Chemical Geology 363, 145-163. doi: 10.1016/j.chemgeo.2013.10.025 (open access)

  5. 'Tetl' Rock

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image, taken by the panoramic camera on NASA's Mars Exploration Rover Spirit during the rover's trek through the 'Columbia Hills' at 'Gusev Crater,' shows the horizontally layered rock dubbed 'Tetl.' Scientists hope to investigate this rock in more detail, aiming to determine whether the rock's layering is volcanic or sedimentary in origin. If for some reason this particular rock is not favorably positioned for grinding and examination by the toolbox of instruments on the rover's robotic arm, Spirit will be within short reach of another similar rock, dubbed 'Coba.' Spirit took this image on its 264th martian day, or sol (Sept. 29, 2004). This is a false-color composite image generated from the panoramic camera's 750-, 530-, and 430-nanometer filters.

  6. Dynamic tensile strength of lunar rock types

    NASA Technical Reports Server (NTRS)

    Cohn, S. N.; Ahrens, T. J.

    1981-01-01

    The dynamic tensile strength of four rocks are determined. A flat plate impact experiment is employed to generate approximately one-microsecond-duration tensile stress pulses in rock samples by superposing rarefaction waves to induce fracture. It is noted that the effect of chemical weathering and other factors has not been explicitly studied. The given tensile strengths are based on a series of experiments on each rock where determination of incipient spallation is made by terminal microscopic examination. The data are generally consistent with previous determinations, at least one of which was for a significantly chemically altered but physically coherent rock.

  7. Art Rocks with Rock Art!

    ERIC Educational Resources Information Center

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  8. Winter Weather: Indoor Safety

    MedlinePlus

    ... page: About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor ... Heat Prevention Guide (Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme ...

  9. Winter Weather Emergencies

    MedlinePlus

    Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

  10. Terby's Rocks

    NASA Technical Reports Server (NTRS)

    2006-01-01

    27 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the light-toned, layered, sedimentary rock outcrops in northern Terby Crater. Terby is located along the north edge of Hellas Planitia. The sedimentary rocks might have been deposited in a greater, Hellas-filling sea -- or not. Today, the rocks are partly covered by dark-toned sediment and debris.

    Location near: 27.2oS, 285.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  11. On nutrients and trace metals: Effects from Enhanced Weathering

    NASA Astrophysics Data System (ADS)

    Amann, T.; Hartmann, J.

    2015-12-01

    The application of rock flour on suitable land ("Enhanced Weathering") is one proposed strategy to reduce the increase of atmospheric CO2 concentrations. At the same time it is an old and established method to add fertiliser and influence soil properties. Investigations of this method focused on the impact on the carbonate system, as well as on engineering aspects of a large-scale application, but potential side effects were never discussed quantitatively. We analysed about 120,000 geochemically characterised volcanic rock samples from the literature. Applying basic statistics, theoretical release rates of nutrients and potential contaminants by Enhanced Weathering were evaluated for typical rock types. Applied rock material can contain significant amounts of essential or beneficial nutrients (potassium, phosphorus, micronutrients). Their release can partly cover the demand of major crops like wheat, rice or corn, thereby increasing crop yield on degraded soils. However, the concentrations of considered elements are variable within a specific rock type, depending on the geological setting. High heavy metal concentrations are found in (ultra-) basic rocks, the class with the highest CO2 drawdown potential. More acidic rocks contain less or no critical amounts, but sequester less CO2. Findings show that the rock selection determines the capability to supply significant amounts of nutrients, which could partly substitute industrial mineral fertiliser usage. At the same time, the release of harmful trace element has to be considered. Through careful selection of regionally available rocks, benefits could be maximised and drawbacks reduced. The deployment of Enhanced Weathering to sequester CO2 and to ameliorate soils necessitates an ecosystem management, considering the release and fate of weathered elements in plants, soils and water. Cropland with degraded soils would benefit while having a net negative CO2 effect, while other carbon dioxide removal strategies, like

  12. Convective Weather Avoidance with Uncertain Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots

  13. Carbonatisation of Weathered Peridotites in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Hövelmann, J.; Austrheim, H.; Beinlich, A.; Munz, I. A.

    2010-12-01

    Enhanced in-situ carbonatisation of ultramafic rocks has been proposed as a strategy for a permanent and safe storage of CO2 in order to reduce anthropogenic greenhouse gas emissions (e.g., Kelemen and Matter 2008). This idea emerged from studies of natural examples demonstrating that ultramafic rocks react extensively with CO2 to form ophicarbonates. However, despite their Mg-rich nature, ultramafic rocks are often associated with calcite (CaCO3) rather than magnesite (MgCO3) and dolomite (CaMg(CO3)2). Whether these so-called ophicalcites represent sedimentary or tectonic breccias or are produced during hydrothermal alteration of ultramafic rocks, has been discussed for many years (e.g., Folk and McBride 1976). The view that reactions between hydrothermal fluids and ultramafic rocks can result in the formation of ophicalcite was recently supported by Beinlich et al. (2010), who documented Ca- and CO2-metasomatism and extreme Mg depletion in serpentinised and weathered peridotite clasts from the conglomerates of the Solund basin (SW Norway). This study also suggests that weathering is an important factor for the carbonatisation of ultramafic rocks. We have performed hydrothermal experiments on weathered peridotites in order to better constrain the mechanisms and conditions that trigger Mg-loss from ultramafic rocks and subsequent calcite precipitation. Un-crushed, partly serpentinised and weathered peridotite samples were allowed to react in a Ca-bearing saline solution under CO2 pressure (PCO2: 130-160 bar) at 200°C. We were able to illustrate the textural and chemical evolution during the reaction through a detailed comparison of the solid and fluid samples before and after the experiments. The initial samples showed a typical mesh texture with veins of serpentine surrounding meshes filled either with fresh or weathered olivine. The experimentally treated samples reveal a strongly reacted rim, predominantly composed of calcite, but still showing ghosts of the

  14. American Weather Stories.

    ERIC Educational Resources Information Center

    Hughes, Patrick

    Weather has shaped United States' culture, national character and folklore; at times it has changed the course of history. The seven accounts compiled in this publication highlight some of the nation's weather experiences from the hurricanes that threatened Christopher Columbus to the peculiar run of bad weather that has plagued American…

  15. Weather Fundamentals: Meteorology. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

  16. Aviation weather services

    NASA Technical Reports Server (NTRS)

    Sprinkle, C. H.

    1983-01-01

    The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.

  17. Severe Weather Perceptions.

    ERIC Educational Resources Information Center

    Abrams, Karol

    Severe weather is an element of nature that cannot be controlled. Therefore, it is important that the general public be aware of severe weather and know how to react quickly and appropriately in a weather emergency. This study, done in the community surrounding the Southern Illinois University at Carbondale, was conducted to compile and analyze…

  18. Hydrochemistry, weathering and weathering rates on Madeira island

    NASA Astrophysics Data System (ADS)

    Van der Weijden, Cornelis H.; Pacheco, Fernando A. L.

    2003-12-01

    Madeira island consists of Miocene to Pleistocene lavas and pyroclasts. Major rock types are alkali-basalts, basanites and hawaiites; principal soil types are leptosols, andosols and cambisols. Our main objective was to link the chemistry of ground waters to weathering reactions and rates. We collected 40 shallow groundwater samples, remote from human activities. With a few exceptions, the ranges of electrical conductivities were 29-176 μS/cm and of pH 5.8-8.5. The calculated PCO 2 was generally higher than the atmospheric value. The contribution of sea salt to the water chemistry was 30±9%. Corrected for sea salt, the cation concentrations (in meq/l) decrease in the order Ca 2+≈Mg 2+>Na +>>>K +. The concentrations of SO 42- and NO 3- are very low. We calculated that the total annual chemical denudation rate in the studied area amounts to 37±12 g/m 2, consuming 0.86±0.38 mol CO 2/m 2. To achieve our main objective, a set of mole balance equations— ( AX= B)—was used, where A is a composite matrix of coefficients, including ratios between stoichiometric coefficients as determined by the weathering reactions and coefficients accounting for unconstrained contributions, B is the vector with a water composition, and X is the set of mole fractions of dissolved primary minerals plus the residual concentrations of the unconstrained contributions. Olivine (Ol), pyroxene (Py) and plagioclase (Pl) were considered to be the major primary minerals, and smectite, vermiculite, halloysite, allophane, gibbsite and hematite the secondary minerals in the weathering reactions. Using iterative procedures, whereby mixtures of secondary products as well as the composition of plagioclase are allowed to change, we selected one best-fit set of weathering reactions for each spring by checking all possible solutions of the mole balances against predefined boundary conditions. At odds with Goldich (1938) sequence, our model results indicate—for most best-fit sets—a weathering rate

  19. Atmospheric CO2 Removal by Enhancing Weathering

    NASA Astrophysics Data System (ADS)

    Koster van Groos, A. F.; Schuiling, R. D.

    2014-12-01

    The increase of the CO2 content in the atmosphere by the release of anthropogenic CO2 may be addressed by the enhancement of weathering at the surface of the earth. The average emission of mantle-derived CO2 through volcanism is ~0.3 Gt/year (109 ton/year). Considering the ~3.000 Gt of CO2 present in the atmosphere, the residence time of CO2 in the earth's atmosphere is ~10,000 years. Because the vast proportion of carbon in biomass is recycled through the atmosphere, CO2 is continuously removed by a series of weathering reactions of silicate minerals and stored in calcium and magnesium carbonates. The addition of anthropogenic CO2 from fossil fuel and cement production, which currently exceeds 35 Gt/year and dwarfs the natural production 100-fold, cannot be compensated by current rates of weathering, and atmospheric CO2 levels are rising rapidly. To address this increase in CO2 levels, weathering rates would have to be accelerated on a commensurate scale. Olivine ((Mg,Fe)2SiO4) is the most reactive silicate mineral in the weathering process. This mineral is the major constituent in relatively common ultramafic rocks such as dunites (olivine content > 90%). To consume the current total annual anthropogenic release of CO2, using a simplified weathering reaction (Mg2SiO4 + 4CO2 + 4H2O --> 2 Mg2+ + 4HCO3- + H4SiO4) would require ~30 Gt/year or ~8-9 km3/year of dunite. This is a large volume; it is about double the total amount of ore and gravel currently mined (~ 17 Gt/year). To mine and crush these rocks to <100 μm costs ~ 8/ton. The transport and distribution over the earth's surface involves additional costs, that may reach 2-5/ton. Thus, the cost of remediation for the release of anthropogenic CO2 is 300-400 billion/year. This compares to a 2014 global GDP of ~80 trillion. Because weathering reactions require the presence of water and proceed more rapidly at higher temperatures, the preferred environments to enhance weathering are the wet tropics. From a socio

  20. Rock Garden

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This false color composite image of the Rock Garden shows the rocks 'Shark' and 'Half Dome' at upper left and middle, respectively. Between these two large rocks is a smaller rock (about 0.20 m wide, 0.10 m high, and 6.33 m from the Lander) that was observed close-up with the Sojourner rover (see PIA00989).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  1. Experimental study on weathering of seafloor volcanic glass by bacteria (Pseudomonas fluorescens) - Implications for the contribution of bacteria to the wate-rock reaction at the Mid-Oceanic Ridge setting

    NASA Astrophysics Data System (ADS)

    Chen, Shun; Wu, Zijun; Peng, Xiaotong

    2014-08-01

    The biologically mediated weathering of the ocean crust has received increasing attention in recent decades, but the rates and the possible mechanism of elemental release during microbe-basalt interactions occurring below the seafloor have not been studied in detail. In this study, we established an experimental weathering study of seafloor natural basaltic glass comparing the effect of microbial activity (Pseudomonas fluorescens) in P-rich and P-poor media with parallel controls containing either nonviable cells or organic acid. The changes in the chemical parameters, including pH, bacterial densities, and ion concentrations (Ca, Mg, Si, Mn, Al, Fe, and P) in the solution, were examined during the different batch experiments. The results showed that the pH decreased from 7.0 to 3.5 and the bacterial density increased from 105 to 108 cells/ml during the first 120 h, and the cell numbers remained constant at 108 cells/ml and the pH increased from 3.5 to 6 between 120 h and 864 h in the P-bearing reactors containing bacteria. In contrast, during all the experimental time, the pH remained close to neutral condition in the abiotic control systems and the dissolution rates increased markedly with a decrease in pH and became minimal at near-neutral pH in P-bearing reactors containing bacteria, where Ca, Si, and Mg release rates were 2- to 4-fold higher than those obtained in chemical systems and biotic P-limited systems. Furthermore, the surfaces of the natural volcanic glass from the biotic systems were colonized by bacteria. Simultaneously, the etch pits were observed by Scanning Electron Microscope, which further indicate that the bacteria may promote the mineral dissolution for energy gain. Some elements (e.g., Fe, Mn, and Al) releasing from natural volcanic glass are likely an important source of the elemental budget in the ocean, and thus the element release and its possible mechanism conducted in this experimental study have potential implications on the

  2. Weatherization and Intergovernmental Program - Weatherization Assistance Program

    SciTech Connect

    2010-06-01

    The U.S. Department of Energy’s (DOE) Weatherization Assistance Program reduces energy costs for low-income households by increasing the energy efficiency of their homes, while ensuring their health and safety.

  3. Beyond the Weather Chart: Weathering New Experiences.

    ERIC Educational Resources Information Center

    Huffman, Amy Bruno

    1996-01-01

    Describes an early childhood educator's approach to teaching children about rain, rainbows, clouds, precipitation, the sun, air, and wind. Recommends ways to organize study topics and describes experiments that can help children better understand the different elements of weather. (MOK)

  4. [Suicide and weather].

    PubMed

    Breuer, H W; Fischbach-Breuer, B R; Breuer, J; Goeckenjan, G; Curtius, J M

    1984-11-01

    In 151 patients, admitted to an intensive care unit after attempted suicide, the possible influence of weather at the time of the attempt was analysed retrospectively. The "biosynoptic daily analysis" of the German Weather Service provided the weather data. There was a 5% and 1%, respectively, significant level for the positive correlation between the time of the attempted suicide and the weather parameters "stable upslide, labile upslide, fog and thunderstorm" and the summarized parameters "warm air, upslide and weather drier than on the two preceding days". Significantly fewer attempts than expected occurred when the weather description was "low pressure and trough situation, labile ground layer--upslide above" and the summarized parameters "subsidence or downslide motion". Besides the individual factors such as the reaction to conflicts and the spectrum of reactions, exogenous factors like weather must be considered as important for the time of suicidal attempt. PMID:6499669

  5. Questa Baseline and Pre-mining Ground-Water Quality Investigation, 7. A Pictorial Record of Chemical Weathering, Erosional Processes, and Potential Debris-flow Hazards in Scar Areas Developed on Hydrothermally Altered Rocks

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Ludington, Steve; Vincent, Kirk R.; Verplanck, Philip L.; Caine, Jonathan S.; Livo, K. Eric

    2009-01-01

    Erosional scar areas developed along the lower Red River basin, New Mexico, reveal a complex natural history of mineralizing processes, rapid chemical weathering, and intense physical erosion during periodic outbursts of destructive, storm-induced runoff events. The scar areas are prominent erosional features with craggy headwalls and steep, denuded slopes. The largest scar areas, including, from east to west, Hottentot Creek, Straight Creek, Hansen Creek, Lower Hansen Creek, Sulfur Gulch, and Goat Hill Gulch, head along high east-west trending ridges that form the northern and southern boundaries of the lower Red River basin. Smaller, topographically lower scar areas are developed on ridge noses in the inner Red River valley. Several of the natural scar areas have been modified substantially as a result of large-scale open-pit and underground mining at the Questa Mine; for example, much of the Sulfur Gulch scar was removed by open pit mining, and several scars are now partially or completely covered by mine waste dumps.

  6. 11. COULTERVILLE ROAD AT ROCK SLIDE AREA WITH HWY 140 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. COULTERVILLE ROAD AT ROCK SLIDE AREA WITH HWY 140 AT REAR. LOOKING NNE. GIS: N-37 43 04.7 / W-119 43 00.3 - Coulterville Road, Between Foresta & All-Weather Highway, Yosemite Village, Mariposa County, CA

  7. [Weathering seasonal variations in karst valley in southwest China].

    PubMed

    Xiao, Qiong; Shen, Li-Cheng; Yang, Lei; Wu, Kun-Yu; Chen, Zhan-Tu

    2012-04-01

    Jialing River is a 1st grade tributary of upstream Yangzi River. In two years, Samples were collected monthly in Wentang Gorge section of Jialing River and analyzed multi-parameters including hydrochemistry and isotopes. Thus, a general result was concluded that the hydrochemical characteristic of Jialing River in Wentang gorge is controlled by weathering of stratum and the hydrochemical type is HCO3(-) -Ca. Most irons were influenced by dilution, which had higher concentrations in dry season than that in rainy season, but nitrate. Nitrate, which was controlled by human activities, has higher concentrations in rainy season. However, some other analyst revealed weathering impacts. The contrast ratio of (Ca(2+) + Mg2+) and HCO3- were between 0.5-1, the same as (Ca(2+) + Mg2+) and (HCO3(-) + SO4(2-)), Which implied that the weathering impacts in this basin was mainly carbonated and sulfate weathering of carbonated, and sulphate rocks weathering was not so significant. The values of delta13C(HCO3- in Jialing River were -8.74 per thousand(-) - 7.36 per thousand, and delta34S(SO)(4)2 - was 14.43 per thousand in dry season and 12.21 per thousand in rainy season. The data of isotopes inferred that, in rainy season sulfate weathering of carbonated and sulphate rocks weathering both had more impacts and sulphate rocks weathering played a more important role than sulfate weathering of carbonated, but, in dry season, carbonated weathering of carbonated was more meaningful. PMID:22720555

  8. Seafloor weathering buffering climate: numerical experiments

    NASA Astrophysics Data System (ADS)

    Farahat, N. X.; Archer, D. E.; Abbot, D. S.

    2013-12-01

    Continental silicate weathering is widely held to consume atmospheric CO2 at a rate controlled in part by temperature, resulting in a climate-weathering feedback [Walker et al., 1981]. It has been suggested that weathering of oceanic crust of warm mid-ocean ridge flanks also has a CO2 uptake rate that is controlled by climate [Sleep and Zahnle, 2001; Brady and Gislason, 1997]. Although this effect might not be significant on present-day Earth [Caldeira, 1995], seafloor weathering may be more pronounced during snowball states [Le Hir et al., 2008], during the Archean when seafloor spreading rates were faster [Sleep and Zahnle, 2001], and on waterworld planets [Abbot et al., 2012]. Previous studies of seafloor weathering have made significant contributions using qualitative, generally one-box, models, and the logical next step is to extend this work using a spatially resolved model. For example, experiments demonstrate that seafloor weathering reactions are temperature dependent, but it is not clear whether the deep ocean temperature affects the temperature at which the reactions occur, or if instead this temperature is set only by geothermal processes. Our goal is to develop a 2-D numerical model that can simulate hydrothermal circulation and resulting alteration of oceanic basalts, and can therefore address such questions. A model of diffusive and convective heat transfer in fluid-saturated porous media simulates hydrothermal circulation through porous oceanic basalt. Unsteady natural convection is solved for using a Darcy model of porous media flow that has been extensively benchmarked. Background hydrothermal circulation is coupled to mineral reaction kinetics of basaltic alteration and hydrothermal mineral precipitation. In order to quantify seafloor weathering as a climate-weathering feedback process, this model focuses on hydrothermal reactions that influence carbon uptake as well as ocean alkalinity: silicate rock dissolution, calcium and magnesium leaching

  9. Pyroclastic Rocks

    NASA Astrophysics Data System (ADS)

    Mahood, Gail A.

    Most of the advances in volcanology during the past 20 years have concerned the recognition, interpretation, and mode of emplacement of pyroclastic rocks. The literature on pyroclastic rocks is widely scattered, in part because the field draws from sedimentology, igneous petrology, physics, and fluid mechanics, and there have been few review papers on the topic. Fisher and Schmincke have done the discipline of volcanology and all field-oriented geologists a great service in assembling material from a wide range of sources in this comprehensive treatment of pyroclastic rocks. With its introduction to the petrology of magmas involved in explosive eruptions in chapter 2 and a complete treatment of magma rheology and the behavior of dissolved and exsolving magmatic volatiles in chapter 3, they lay sufficient groundwork that anyone with a rudimentary knowledge of geology can understand the book.

  10. Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes

    USGS Publications Warehouse

    Jones, B.F.; Herman, J.S.

    2008-01-01

    Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and oxyhydroxides, and solute fluxes (Meunier and Velde, 1979). The chemical composition of the clay-mineral product is often ignored. However, in earlier investigations, the saprolitic weathering profile at the South Fork Brokenback Run (SFBR) watershed, Shenandoah National Park, Virginia, was characterized extensively in terms of its mineralogical and chemical composition (Piccoli, 1987; Pochatila et al., 2006; Jones et al., 2007) and its basic hydrology. O'Brien et al. (1997) attempted to determine the contribution of primary mineral weathering to observed stream chemistry at SFBR. Mass-balance model results, however, could provide only a rough estimate of the weathering reactions because idealized mineral compositions were utilized in the calculations. Making use of detailed information on the mineral occurrence in the regolith, the objective of the present study was to evaluate the effects of compositional variation on mineral-solute mass-balance modelling and to generate plausible quantitative weathering reactions that support both the chemical evolution of the surface water and ground water in the catchment, as well as the mineralogical evolution of the weathering profile. ?? 2008 The Mineralogical Society.

  11. Weathering profiles in granites, Sierra Norte (Córdoba, Argentina)

    NASA Astrophysics Data System (ADS)

    Kirschbaum, Alicia; Martínez, Estela; Pettinari, Gisela; Herrero, Silvana

    2005-09-01

    Two weathering profiles evolved on peneplain-related granites in Sierra Norte, Córdoba province, were examined. Several weathering levels, of no more than 2 m thickness, were studied in these profiles. They had developed from similar parent rock, which had been exposed to hydrothermal processes of varying intensity. Fracturing is the most notable feature produced by weathering; iron oxides and silica subsequently filled these fractures, conferring a breccia-like character to the rock. The clay minerals are predominantly illitic, reflecting the mineral composition of the protolith. Smaller amounts of interstratified I/S RO type are also present, as well as scarce caolinite+chlorite that originated from the weathering of feldspar and biotite, respectively. The geochemical parameters define the weathering as incipient, in contrast to the geomorphological characteristics of Sierra Norte, which point to a long weathering history. This apparent incompatibility could be due to the probable erosion of the more weathered levels of the ancient peneplains, of which only a few relicts remain. Similar processes have been described at different sites in the Sierras Pampeanas. Reconstruction and dating of the paleosurfaces will make it possible to set time boundaries on the weathering processes studied and adjust the paleographic and paleoclimatic interpretations of this great South American region.

  12. NASA Connect: 'Plane Weather'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Excerpt from the NASA Connect show 'Plane Weather' This clip explains what high and low pressure weather systems are, and how these affect weather patterns. Weather affects our daily lives. The elements of weather: rain, wind, fog, ice and snow affect the operation and flight of an airplane. In this program, NASA and FAA researchers will introduce students to math, science, and weather; demonstrate how these elements influence flight; and show how NASA and FAA research is used to limit the effects of these elements on flight. Students will examine: the tools, techniques, and technologies used by engineers and scientists to detect these and other climatological factors affecting aircraft in flight. The lesson and classroom experiment will involve students in the scientific process and emphasizing problem solving, measurement, and reasoning skills.

  13. RBSP Space Weather data

    NASA Astrophysics Data System (ADS)

    Weiss, M.; Fox, N. J.; Mauk, B. H.; Barnes, R. J.; Potter, M.; Romeo, G.; Smith, D.

    2012-12-01

    On August 23, 2012, NASA will launch two identical probes into the radiation belts to provide unprecedented insight into the physical processes and dynamics of near-Earth space. The RBSP mission in addition to the scientific data return, provides a 1Kbps real-time space weather broadcast data in support of real time space weather modeling, forecast and prediction efforts. Networks of ground stations have been identified to downlink the space weather data. The RBSP instrument suites have selected space weather data to be broadcast from their collected space data on board the spacecraft, a subset from measurements based on information normally available to the instrument. The data subset includes particle fluxes at a variety of energies, and magnetic and electric field data. This selected space weather data is broadcast at all times through the primary spacecraft science downlink antennas when an observatory is not in a primary mission-related ground contact. The collected data will resolve important scientific issues and help researchers develop and improve various models for the radiation belts that can be used by forecasters to predict space weather phenomena and alert astronauts and spacecraft operators to potential hazards. The near real-time data from RBSP will be available to monitor and analyze current environmental conditions, forecast natural environmental changes and support anomaly resolution. The space weather data will be available on the RBSP Science Gateway at http://athena.jhuapl.edu/ and will provide access to the space weather data received from the RBSP real-time space weather broadcast. The near real-time data will be calibrated and displayed on the web as soon as possible. The CCMC will ingest the RBSP space weather data into real-time models. The raw space weather data will be permanently archived at APL. This presentation will provide a first look at RBSP space weather data products.

  14. Weather and climate

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human losses caused by weather, (3) development of space system capability to manage and control air pollutant concentrations, and (4) establish mechanisms for the national examination of deliberate and inadvertent means for modifying weather and climate.

  15. Cockpit weather information needs

    NASA Technical Reports Server (NTRS)

    Scanlon, Charles H.

    1992-01-01

    The primary objective is to develop an advanced pilot weather interface for the flight deck and to measure its utilization and effectiveness in pilot reroute decision processes, weather situation awareness, and weather monitoring. Identical graphical weather displays for the dispatcher, air traffic control (ATC), and pilot crew should also enhance the dialogue capabilities for reroute decisions. By utilizing a broadcast data link for surface observations, forecasts, radar summaries, lightning strikes, and weather alerts, onboard weather computing facilities construct graphical displays, historical weather displays, color textual displays, and other tools to assist the pilot crew. Since the weather data is continually being received and stored by the airborne system, the pilot crew has instantaneous access to the latest information. This information is color coded to distinguish degrees of category for surface observations, ceiling and visibilities, and ground radar summaries. Automatic weather monitoring and pilot crew alerting is accomplished by the airborne computing facilities. When a new weather information is received, the displays are instantaneously changed to reflect the new information. Also, when a new surface or special observation for the intended destination is received, the pilot crew is informed so that information can be studied at the pilot's discretion. The pilot crew is also immediately alerted when a severe weather notice, AIRMET or SIGMET, is received. The cockpit weather display shares a multicolor eight inch cathode ray tube and overlaid touch panel with a pilot crew data link interface. Touch sensitive buttons and areas are used for pilot selection of graphical and data link displays. Time critical ATC messages are presented in a small window that overlays other displays so that immediate pilot alerting and action can be taken. Predeparture and reroute clearances are displayed on the graphical weather system so pilot review of weather along

  16. Weather assessment and forecasting

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Data management program activities centered around the analyses of selected far-term Office of Applications (OA) objectives, with the intent of determining if significant data-related problems would be encountered and if so what alternative solutions would be possible. Three far-term (1985 and beyond) OA objectives selected for analyses as having potential significant data problems were large-scale weather forecasting, local weather and severe storms forecasting, and global marine weather forecasting. An overview of general weather forecasting activities and their implications upon the ground based data system is provided. Selected topics were specifically oriented to the use of satellites.

  17. Pilot Weather Advisor System

    NASA Technical Reports Server (NTRS)

    Lindamood, Glenn; Martzaklis, Konstantinos Gus; Hoffler, Keith; Hill, Damon; Mehrotra, Sudhir C.; White, E. Richard; Fisher, Bruce D.; Crabill, Norman L.; Tucholski, Allen D.

    2006-01-01

    The Pilot Weather Advisor (PWA) system is an automated satellite radio-broadcasting system that provides nearly real-time weather data to pilots of aircraft in flight anywhere in the continental United States. The system was designed to enhance safety in two distinct ways: First, the automated receipt of information would relieve the pilot of the time-consuming and distracting task of obtaining weather information via voice communication with ground stations. Second, the presentation of the information would be centered around a map format, thereby making the spatial and temporal relationships in the surrounding weather situation much easier to understand

  18. Weather it's Climate Change?

    NASA Astrophysics Data System (ADS)

    Bostrom, A.; Lashof, D.

    2004-12-01

    For almost two decades both national polls and in-depth studies of global warming perceptions have shown that people commonly conflate weather and global climate change. Not only are current weather events such as anecdotal heat waves, droughts or cold spells treated as evidence for or against global warming, but weather changes such as warmer weather and increased storm intensity and frequency are the consequences most likely to come to mind. Distinguishing weather from climate remains a challenge for many. This weather 'framing' of global warming may inhibit behavioral and policy change in several ways. Weather is understood as natural, on an immense scale that makes controlling it difficult to conceive. Further, these attributes contribute to perceptions that global warming, like weather, is uncontrollable. This talk presents an analysis of data from public opinion polls, focus groups, and cognitive studies regarding people's mental models of and 'frames' for global warming and climate change, and the role weather plays in these. This research suggests that priming people with a model of global warming as being caused by a "thickening blanket of carbon dioxide" that "traps heat" in the atmosphere solves some of these communications problems and makes it more likely that people will support policies to address global warming.

  19. Classic Rock

    ERIC Educational Resources Information Center

    Beem, Edgar Allen

    2004-01-01

    While "early college" programs designed for high-school-age students are beginning to proliferate nationwide, a small New England school has been successfully educating teens for nearly four decades. In this article, the author features Simon's Rock, a small liberal arts college located in the Great Barrington, Massachusetts, that has been…

  20. Seafloor Weathering As a Long-Term Climate Regulation Mechanism

    NASA Astrophysics Data System (ADS)

    Farahat, N. X.; Abbot, D. S.; Archer, D. E.

    2014-12-01

    The global carbon cycle determines the distribution of carbon between the atmosphere, ocean, and solid earth. Carbon from the mantle enters the Earth's surficial environment as CO2 by volcanic outgassing, and carbon is buried in the oceanic crust as carbonate rocks during silicate rock weathering. The subduction of carbonate-rich oceanic plates returns carbon to the mantle, closing the cycle. Subtle adjustments in continental silicate weathering, widely held to consume atmospheric CO2 at a rate controlled by climate, are believed to have maintained habitable conditions throughout Earth's history. This long term climate regulation mechanism is known as a climate-weathering feedback. Seafloor weathering, low-temperature basalt alteration and carbonate precipitation in the permeable upper oceanic crust, has been proposed as a climate-weathering feedback as well, but the link to climate is presently poorly understood. Such a climate regulation mechanism would be particularly important on waterworld planets where continental silicate weathering cannot regulate climate. It has so far not been possible to determine whether changes in seafloor weathering could contribute to climate regulation on Earth or in a waterworld scenario because the necessary modeling framework has not yet been developed. However, advances in porous media flow modeling and reactive transport modeling, as well as the availability of inexpensive computational power, allow the seafloor weathering problem to be looked at in greater detail. We have developed a spatially resolved two-dimmensional (2D) numerical model of seafloor weathering in the permeable upper oceanic crust. This model simulates 2D off-axis hydrothermal flow coupled to geochemical alteration of seafloor basalt by modeling reactive transport of chemical species in seawater-derived hydrothermal fluids. The focus of this research is to use the model to determine the effect of geological and climatic factors on seafloor weathering, which

  1. Weathering of sulfides on Mars

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.; Fisher, Duncan S.

    1987-01-01

    Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produce degradation products in the Martian regolith. By analogy and terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni, and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato-and hydroxo-complex ions and sols formed gossan above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite), and silica (opal). Underlying groundwater, now permafrost contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates, and phyllosilicates during dust storms on Mars.

  2. Erosion and the rocks of Venus

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1976-01-01

    Photographs of the surface of Venus returned by the Venera 9 and 10 spacecraft have revealed the presence of smooth and angular rockline forms. Two mechanisms previously suggested (Sagan, 1975) for erosion of crater ramparts on the surface of Venus might also explain the erosion of rocks. Chemical weathering by the hydrochloric, hydrofluoric, and sulfuric acids present in the atmosphere of Venus may have been sufficient to erode angular projections of silicous rocks. Alternatively, the contours of rocks containing such low-melting materials as NaOH, KOH, HgS and KNO2 may have softened as the result of exposure to the high surface temperatures of the planet.

  3. Weather and emotional state

    NASA Astrophysics Data System (ADS)

    Spasova, Z.

    2010-09-01

    Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions

  4. Iron isotopic fractionation during continental weathering

    SciTech Connect

    Fantle, Matthew S.; DePaolo, Donald J.

    2003-10-01

    The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

  5. Direct quantification of long-term rock nitrogen inputs to temperate forest ecosystems.

    PubMed

    Morford, Scott L; Houlton, Benjamin Z; Dahlgren, Randy A

    2016-01-01

    Sedimentary and metasedimentary rocks contain large reservoirs of fixed nitrogen (N), but questions remain over the importance of rock N weathering inputs in terrestrial ecosystems. Here we provide direct evidence for rock N weathering (i.e., loss of N from rock) in three temperate forest sites residing on a N-rich parent material (820-1050 mg N kg(-1); mica schist) in the Klamath Mountains (northern California and southern Oregon), USA. Our method combines a mass balance model of element addition/ depletion with a procedure for quantifying fixed N in rock minerals, enabling quantification of rock N inputs to bioavailable reservoirs in soil and regolith. Across all sites, -37% to 48% of the initial bedrock N content has undergone long-term weathering in the soil. Combined with regional denudation estimates (sum of physical + chemical erosion), these weathering fractions translate to 1.6-10.7 kg x ha(-1) x yr(-1) of rock N input to these forest ecosystems. These N input fluxes are substantial in light of estimates for atmospheric sources in these sites (4.5-7.0 kg x ha(-1) x yr(-1)). In addition, N depletion from rock minerals was greater than sodium, suggesting active biologically mediated weathering of growth-limiting nutrients compared to nonessential elements. These results point to regional tectonics, biologically mediated weathering effects, and rock N chemistry in shaping the magnitude of rock N inputs to the forest ecosystems examined. PMID:27008775

  6. Teacher's Weather Sourcebook.

    ERIC Educational Resources Information Center

    Konvicka, Tom

    This book is a teaching resource for the study of weather-related phenomena. A "weather unit" is often incorporated into school study because of its importance to our daily lives and because of its potential to cut across disciplinary content. This book consists of two parts. Part I covers the major topics of atmospheric science such as the modern…

  7. KSC Weather and Research

    NASA Technical Reports Server (NTRS)

    Maier, Launa; Huddleston, Lisa; Smith, Kristin

    2016-01-01

    This briefing outlines the history of Kennedy Space Center (KSC) Weather organization, past research sponsored or performed, current organization, responsibilities, and activities, the evolution of weather support, future technologies, and an update on the status of the buoys located offshore of Cape Canaveral Air Force Station and KSC.

  8. Weather Fundamentals: Clouds. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  9. Mild and Wild Weather.

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Presents background information and six activities that focus on clouds, precipitation, and stormy weather. Each activity includes an objective, recommended age level(s), subject area(s), and instructional strategies. Also provided are two ready-to-copy pages (a coloring page on lightning and a list of weather riddles to solve). (JN)

  10. People and Weather.

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Provides: (1) background information on ways weather influences human lives; (2) activities related to this topic; and (3) a ready-to-copy page with weather trivia. Each activity includes an objective, list of materials needed, recommended age level(s), subject area(s), and instructional strategies. (JN)

  11. World weather program

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A brief description of the Global Weather Experiment is presented. The world weather watch program plan is described and includes a global observing system, a global data processing system, a global telecommunication system, and a voluntary cooperation program. A summary of Federal Agency plans and programs to meet the challenges of international meteorology for the two year period, FY 1980-1981, is presented.

  12. Exercising in Cold Weather

    MedlinePlus

    ... www.nia.nih.gov/Go4Life Exercising in Cold Weather Exercise has benefits all year, even during winter. ... activities when it’s cold outside: l Check the weather forecast. If it’s very windy or cold, exercise ...

  13. Weather and Culture.

    ERIC Educational Resources Information Center

    Contemporary Learning Center, Houston, TX.

    This document is a minicourse on the interaction of weather, environment, and culture. It is designed for the high school student to read and self-administer. Performance objectives, enabling activities, and postassessment questions are given for each of eight modules. The modules are: (1) Basic Facts About Your Weather Known As Rain, (2) The…

  14. Home Weatherization Visit

    ScienceCinema

    Chu, Steven

    2013-05-29

    Secretary Steven Chu visits a home that is in the process of being weatherized in Columbus, OH, along with Ohio Governor Ted Strickland and Columbus Mayor Michael Coleman. They discuss the benefits of weatherization and how funding from the recovery act is having a direct impact in communities across America.

  15. Weathering Database Technology

    ERIC Educational Resources Information Center

    Snyder, Robert

    2005-01-01

    Collecting weather data is a traditional part of a meteorology unit at the middle level. However, making connections between the data and weather conditions can be a challenge. One way to make these connections clearer is to enter the data into a database. This allows students to quickly compare different fields of data and recognize which…

  16. On Observing the Weather

    ERIC Educational Resources Information Center

    Crane, Peter

    2004-01-01

    Rain, sun, snow, sleet, wind... the weather affects everyone in some way every day, and observing weather is a terrific activity to attune children to the natural world. It is also a great way for children to practice skills in gathering and recording information and to learn how to use simple tools in a standardized fashion. What better way to…

  17. Fabulous Weather Day

    ERIC Educational Resources Information Center

    Marshall, Candice; Mogil, H. Michael

    2007-01-01

    Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

  18. The Home Weather Station.

    ERIC Educational Resources Information Center

    Steinke, Steven D.

    1991-01-01

    Described is how an amateur weather observer measures and records temperature and precipitation at a well-equipped, backyard weather station. Directions for building an instrument shelter and a description of the instruments needed for measuring temperature and precipitation are included. (KR)

  19. Weatherizing a Structure.

    ERIC Educational Resources Information Center

    Metz, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with weatherizing a structure. Its objective is for the student to be able to analyze factors related to specific structures that indicate need for weatherizing activities and to determine steps to correct defects in structures that…

  20. Weather Fundamentals: Wind. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) describes the roles of the sun, temperature, and air pressure in creating the incredible power…

  1. Aviation Weather Program (AWP)

    NASA Technical Reports Server (NTRS)

    Foote, Brant

    1993-01-01

    The Aviation Weather Program (AWP) combines additional weather observations, improved forecast technology, and more efficient distribution of information to pilots, controllers, and automated systems to improve the weather information provided to the air traffic control system, pilots, and other users of aviation weather information. Specific objectives include the needs to: improve airport and en-route capacity by accurate, high resolution, timely forecasts of changing weather conditions affecting airport and en-route operations; improve analyses and forecasts of upper-level winds for efficient flight planning and traffic management; and increase flight safety through improved aviation weather hazard forecasting (e.g. icing, turbulence, severe storms, microbursts, or strong winds). The AWP would benefit from participation in a cooperative multiscale experiment by obtaining data for: evaluation of aviation weather forecast products, analysis of four dimensional data assimilation schemes, and experimental techniques for retrieving aerosol and other visibility parameters. A multiscale experiment would also be helpful to AWP by making it possible to evaluate the added benefit of enhanced data sets collected during the experiment on those forecast and analysis products. The goals of the Coperative Multiscale Experiment (CME) are an essential step in attaining the long-term AWP objective of providing two-to-four hour location-specific forecasts of significant weather. Although the possibility of a funding role for the AWP in the CME is presently unclear, modest involvement of Federal Aviation Administration (FAA)/AWP personnel could be expected.

  2. Designing a Weather Station

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

  3. NASA Connect: 'Plane Weather'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Excerpt from the NASA Connect show 'Plane Weather' This clip explains how our weather occurs, and why Solar radiation is responsible. Weather affects our daily lives. The elements of weather: rain, wind, fog, ice and snow affect the operation and flight of an airplane. In this program, NASA and FAA researchers will introduce students to math, science, and weather; demonstrate how these elements influence flight; and show how NASA and FAA research is used to limit the effects of these elements on flight. Students will examine: the tools, techniques, and technologies used by engineers and scientists to detect these and other climatological factors affecting aircraft in flight. The lesson and classroom experiment will involve students in the scientific process and emphasizing problem solving, measurement, and reasoning skills.

  4. NASA Connect: 'Plane Weather'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Excerpt from the NASA Connect show 'Plane Weather' This clip explains what high and low pressure weather systems are, and how they form. Weather affects our daily lives. The elements of weather: rain, wind, fog, ice and snow affect the operation and flight of an airplane. In this program, NASA and FAA researchers will introduce students to math, science, and weather; demonstrate how these elements influence flight; and show how NASA and FAA research is used to limit the effects of these elements on flight. Students will examine: the tools, techniques, and technologies used by engineers and scientists to detect these and other climatological factors affecting aircraft in flight. The lesson and classroom experiment will involve students in the scientific process and emphasizing problem solving, measurement, and reasoning skills.

  5. Poohbear Rock

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image, taken by Sojourner's front right camera, was taken when the rover was next to Poohbear (rock at left) and Piglet (not seen) as it looked out toward Mermaid Dune. The textures differ from the foreground soil containing a sorted mix of small rocks, fines and clods, from the area a bit ahead of the rover where the surface is covered with a bright drift material. Soil experiments where the rover wheels dug in the soil revealed that the cloudy material exists underneath the drift.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  6. Meridiani Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    16 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the complex surfaces of some of the light- and intermediate-toned sedimentary rock exposed by erosion in eastern Sinus Meridiani. Similar rocks occur at the Mars Exploration Rover, Opportunity, site, but they are largely covered by windblown sand and granules. The dark feature with a rayed pattern is the product of a meteor impact.

    Location near: 0.8oN, 355.2oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  7. Terby's Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    25 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light-toned, layered, sedimentary rock outcrops in the crater, Terby. The crater is located on the north rim of Hellas Basin. If one could visit the rocks in Terby, one might learn from them whether they formed in a body of water. It is possible, for example, that Terby was a bay in a larger, Hellas-wide sea.

    Location near: 27.9oS, 285.7oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  8. White Rock

    NASA Technical Reports Server (NTRS)

    2005-01-01

    14 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of the famous 'White Rock' feature in Pollack Crater in the Sinus Sabaeus region of Mars. The light-toned rock is not really white, but its light tone caught the eye of Mars geologists as far back as 1972, when it was first spotted in images acquired by Mariner 9. The light-toned materials are probably the remains of a suite of layered sediments that once spread completely across the interior of Pollack Crater. Dark materials in this image include sand dunes and large ripples.

    Location near: 8.1oS, 335.1oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  9. White Rock

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 19 April 2002) The Science 'White Rock' is the unofficial name for this unusual landform which was first observed during the Mariner 9 mission in the early 1970's. As later analysis of additional data sets would show, White Rock is neither white nor dense rock. Its apparent brightness arises from the fact that the material surrounding it is so dark. Images from the Mars Global Surveyor MOC camera revealed dark sand dunes surrounding White Rock and on the floor of the troughs within it. Some of these dunes are just apparent in the THEMIS image. Although there was speculation that the material composing White Rock could be salts from an ancient dry lakebed, spectral data from the MGS TES instrument did not support this claim. Instead, the White Rock deposit may be the erosional remnant of a previously more continuous occurrence of air fall sediments, either volcanic ash or windblown dust. The THEMIS image offers new evidence for the idea that the original deposit covered a larger area. Approximately 10 kilometers to the southeast of the main deposit are some tiny knobs of similarly bright material preserved on the floor of a small crater. Given that the eolian erosion of the main White Rock deposit has produced isolated knobs at its edges, it is reasonable to suspect that the more distant outliers are the remnants of a once continuous deposit that stretched at least to this location. The fact that so little remains of the larger deposit suggests that the material is very easily eroded and simply blows away. The Story Fingers of hard, white rock seem to jut out like icy daggers across a moody Martian surface, but appearances can be deceiving. These bright, jagged features are neither white, nor icy, nor even hard and rocky! So what are they, and why are they so different from the surrounding terrain? Scientists know that you can't always trust what your eyes see alone. You have to use other kinds of science instruments to measure things that our eyes can

  10. Hydrologic regulation of chemical weathering and the geologic carbon cycle.

    PubMed

    Maher, K; Chamberlain, C P

    2014-03-28

    Earth's temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks that operates over million-year time scales. To explain variations in the strength of the weathering feedback, we present a model for silicate weathering that regulates climatic and tectonic forcing through hydrologic processes and imposes a thermodynamic limit on weathering fluxes, based on the physical and chemical properties of river basins. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to the situation today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts, even in the absence of appreciable changes in CO2 degassing rates. PMID:24625927

  11. Carbonate weathering along a climatic gradient in the Jura Mountains

    NASA Astrophysics Data System (ADS)

    Gaillardet, J.; Calmels, D.; Francois, L. M.

    2013-12-01

    A significant portion of the Critical Zone of the Earth is developed on carbonate rocks. In order to investigate the control of carbonate weathering and in particular its response to climate change, we sampled rivers and springs in a well-drained pure carbonate area subjected to strong environmental gradients, the Jura Mountains, Western Europe. The intensity of carbonate weathering, shows a gradual two-fold increase with decreasing elevation from 1200m to 300m. These changes cannot be interpreted in terms of thermodynamic equilibrium and changes of the thermodynamic constants with temperature. The change in vegetation species from deciduous forest in plains to coniferous forest in altitude appears as a major control. Using the ecological and hydrological ASPECTS model, we show that the availability of soil CO2, known as a main weathering agent of rocks, is directly linked to the spatial distribution of vegetation species over the study area. The type of vegetation drives temporal and spatial variations of the carbon and water budgets in soils and therefore partly controls both carbonate weathering intensity and rates. At a given runoff, carbonate weathering rates are classically 20-30% higher under deciduous vegetation cover than under coniferous forest. This study demonstrates that carbonate weathering is strongly sensitive to the ecosystem dynamics, a conclusion that may be much more general, and suggests that carbonate weathering quickly reacts to any global change and/or land use modification.

  12. The Space Weather Reanalysis

    NASA Astrophysics Data System (ADS)

    Kihn, E. A.; Ridley, A. J.; Zhizhin, M.

    2002-12-01

    The objective of this project is to generate a complete 11 year space weather representation using physically consistent data-driven space weather models. The project will create a consistent, integrated historical record of the near Earth space environment by coupling observational data from space environmental monitoring systems archived at NGDC with data-driven, physically based numerical models. The resulting product will be an enhanced look at the space environment on consistent grids, time resolution, coordinate systems and containing key fields allowing an interested user to quickly and easily incorporate the impact of the near-Earth space climate in environmentally sensitive models. Currently there are no easily accessible long term climate archives available for the space-weather environment. Just as with terrestrial weather it is crucial to understand both daily weather forecasts as well as long term climate changes, so this project will demonstrate the ability to generate a meaningful and physically derived space weather climatology. The results of this project strongly support the DOD's Environmental Scenario Generator (ESG) project. The ESG project provides tools for intellegent data mining, classification and event detection which could be applied to a historical space-weather database. The two projects together provide a suite of tools for the user interested in modeling the effect of the near-earth space environment. We will present results and methodologies developed during the first two years of effort in the project.

  13. Geochemistry of large river suspended sediments: Silicate weathering or recycling tracer?

    SciTech Connect

    Gaillardet, J.; Dupre, B.; Allegre, C.J.

    1999-12-01

    This study focuses on the major and trace element composition of suspended sediments transported by the world's largest rivers. Its main purpose is to answer the following question: is the degree of weathering of modern river-borne particles consistent with the estimated river dissolved loads derived from silicate weathering? In agreement with the well known mobility of elements during weathering of continental rocks, the authors confirm that river sediments are systematically depleted in Na, K, Ba with respect to the Upper Continental Crust. For each of these mobile elements, a systematics of weathering indexes of river-borne solids is attempted. A global consistency is found between all these indexes. Important variations in weathering intensities exist. A clear dependence of weathering intensities with climate is observed for the rivers draining mostly lowlands. However, no global correlation exists between weathering intensities and climatic or relief parameters because the trend observed for lowlands is obscured by rivers draining orogenic zones. An inverse correlation between weathering intensities and suspended sediment concentrations is observed showing that the regions having the highest rates of physical denudation produce the least weathered sediments. Finally, chemical and physical weathering are compared through the use of a simple steady state model. The authors show that the weathering intensities of large river suspended sediments can only be reconciled with the (silicate-derived) dissolved load or rivers, by admitting that most of the continental rocks submitted to weathering in large river basins have already suffered previous weathering cycles. A simple graphical method is proposed for calculating the proportion of sedimentary recycling in large river basins. Finally, even if orogenic zones produce weakly weathered sediments, the authors emphasize the fact that silicate chemical weathering rates (and hence CO{sub 2} consumption rates by silicate

  14. Food Safety for Warmer Weather

    MedlinePlus

    ... Fight Off Food Poisoning Food Safety for Warmer Weather In warm-weather months, who doesn’t love to get outside ... to keep foods safe to eat during warmer weather. If you’re eating or preparing foods outside, ...

  15. Weather--An Integrated Unit

    ERIC Educational Resources Information Center

    McConnell, Vivian

    1976-01-01

    Outlined is a two week unit on weather offered as independent study for sixth- and seventh-year students in Vancouver, Canada, schools. Included is a section on weather lore and a chart of weather symbols. (SL)

  16. Hypothermia: A Cold Weather Hazard

    MedlinePlus

    ... Weather Hazard Heath and Aging Hypothermia: A Cold Weather Hazard What Are The Signs Of Hypothermia? Taking ... cold air. But, not everyone knows that cold weather can also lower the temperature inside your body. ...

  17. Environmental Education Tips: Weather Activities.

    ERIC Educational Resources Information Center

    Brainard, Audrey H.

    1989-01-01

    Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

  18. Sun, weather, and climate

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Goldberg, R. A.

    1985-01-01

    The general field of sun-weather/climate relationships, that is, apparent weather and climate responses to solar activity is introduced and theoretical and experimental suggestions for further research to identify and investigate the unknown causal mechanisms are provided. Topics of discussion include: (1) solar-related correlation factors and energy sources; (2) long-term climatic trends; (3) short-term meteorological correlations; (4) miscellaneous obscuring influences; (5) physical processes and mechanisms; (6) recapitulation of sun-weather relationships; and (7) guidelines for experiments.

  19. Release of biodegradable dissolved organic matter from ancient sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Schillawski, Sarah; Petsch, Steven

    2008-09-01

    Sedimentary rocks contain the largest mass of organic carbon on Earth, yet these reservoirs are not well integrated into modern carbon budgets. Here we describe the release of dissolved organic matter (DOM) from OM-rich sedimentary rocks under simulated weathering conditions. Results from column experiments demonstrate slow, sustained release of DOM from ancient sedimentary rocks under simulated weathering conditions. 1H-NMR analysis of shale-derived DOM reveals a highly aliphatic, carbohydrate-poor material distinct from other natural DOM pools. Shale-derived DOM is rapidly assimilated and biodegraded by aerobic heterotrophic bacteria. Consequently, no compositional signature of shale-derived DOM other than 14C-depletion is likely to persist in rivers or other surface reservoirs. Combined, these efforts show that dissolution provides a mechanism for the conversion of refractory kerogen into labile biomass, linking rock weathering with sedimentary OM oxidation and the delivery of aged OM to rivers and ocean margins.

  20. Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    6 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows outcrops of sedimentary rocks in a crater located just north of the Sinus Meridiani region. Perhaps the crater was once the site of a martian lake.

    Location near: 2.9oN, 359.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  1. Redistribution of uranium and thorium series isotopes during isovolumetric weathering of granite

    NASA Astrophysics Data System (ADS)

    Michel, Jacqueline

    1984-06-01

    Previous studies of the distribution of U and Th in parent versus weathered granites have shown both depletion and enrichment of these elements during weathering. In this study, the distribution of U and Th decay series isotopes was determined in a weathering profile of a granitic saprolite, which showed textural preservation indicating isovolumetric weathering. Two types of dissolution methods were used: a whole-rock dissolution and a sodium-citrate dithionite leach to preferentially attack noncrystalline phases of weathering products. Using volume-based activities, 45-70 percent of the total 232Th was gradually removed during weathering. Although the whole-rock 228Th /232Th activity ratios were in equilibrium, there were large excesses of 228Th in the leachable fraction of both parent rock ( 228Th /232Th = 2.06 ) and partially weathered saprolite ( 228Th /232Th = 3-6.5 ), due to alpha recoil and release of daughter 228Th to the weathering rind of the mineral grain. For the most weathered sample, 81 percent of the thorium was in the teachable fraction and 228Th /232Th = 1 , indicating that even the more resistant minerals were attacked. The total U activities showed as much variation in the six parent rock samples as in the weathered profile, and 234U /238U were in equilibrium in both the whole-rock and leachable fractions. 230Th was deficient relative to 234U and 226Ra in both fractions, suggesting recent addition of U and Ra to the entire profile. The large variation in U was not from absorption onto the intermediate weathering products, because only 11-23 percent of the U was in the leachable fraction.

  2. Thermal Inertia of Rocks and Rock Populations

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

    2001-01-01

    The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

  3. Weathering in a Cup.

    ERIC Educational Resources Information Center

    Stadum, Carol J.

    1991-01-01

    Two easy student activities that demonstrate physical weathering by expansion are described. The first demonstrates ice wedging and the second root wedging. A list of the needed materials, procedure, and observations are included. (KR)

  4. Weathering of Martian Evaporites

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; Velbel, M. A.; Thomas-Keprta, K. L.; Longazo, T. G.; McKay, D. S.

    2001-01-01

    Evaporites in martian meteorites contain weathering or alteration features that may provide clues about the martian near-surface environment over time. Additional information is contained in the original extended abstract.

  5. Waste glass weathering

    SciTech Connect

    Bates, J.K.; Buck, E.C.

    1993-12-31

    The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared to release under standard leaching conditions. While the comparison between the release under weathering and leaching conditions is not exact, due to variability of reaction in humid air, evidence is presented of radionuclide release under a variety of conditions. These results suggest that both the amount and form of radionuclide release can be affected by the weathering of glass.

  6. Americans and Their Weather

    NASA Astrophysics Data System (ADS)

    Meyer, William B.

    2000-07-01

    This revealing book synthesizes research from many fields to offer the first complete history of the roles played by weather and climate in American life from colonial times to the present. Author William B. Meyer characterizes weather events as neutral phenomena that are inherently neither hazards nor resources, but can become either depending on the activities with which they interact. Meyer documents the ways in which different kinds of weather throughout history have represented hazards and resources not only for such exposed outdoor pursuits as agriculture, warfare, transportation, construction, and recreation, but for other realms of life ranging from manufacturing to migration to human health. He points out that while the weather and climate by themselves have never determined the course of human events, their significance as been continuously altered for better and for worse by the evolution of American life.

  7. Weather Information Processing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Science Communications International (SCI), formerly General Science Corporation, has developed several commercial products based upon experience acquired as a NASA Contractor. Among them are METPRO, a meteorological data acquisition and processing system, which has been widely used, RISKPRO, an environmental assessment system, and MAPPRO, a geographic information system. METPRO software is used to collect weather data from satellites, ground-based observation systems and radio weather broadcasts to generate weather maps, enabling potential disaster areas to receive advance warning. GSC's initial work for NASA Goddard Space Flight Center resulted in METPAK, a weather satellite data analysis system. METPAK led to the commercial METPRO system. The company also provides data to other government agencies, U.S. embassies and foreign countries.

  8. From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.

    ERIC Educational Resources Information Center

    Philippines Univ., Quezon City. Science Education Center.

    This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

  9. Salt weathering on Mars

    NASA Technical Reports Server (NTRS)

    Malin, M. C.

    1974-01-01

    Mariner 9 photographs of Mars indicate that significant erosion has occurred on that planet. Although several possible erosion mechanisms have been proposed, most terrestrial weathering mechanisms cannot function in the present Martian environment. Salt weathering, believed to be active in the Antarctic dry valleys, is especially suited to Mars, given the presence of salts and small amounts of water. Volcanic salts are probably available, and the association of salts and water is likely from both thermodynamic and geologic considerations.

  10. Cockpit weather information system

    NASA Technical Reports Server (NTRS)

    Tu, Jeffrey Chen-Yu (Inventor)

    2000-01-01

    Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

  11. Rock Driller

    NASA Technical Reports Server (NTRS)

    Peterson, Thomas M.

    2001-01-01

    The next series of planetary exploration missions require a method of extracting rock and soil core samples. Therefore a prototype ultrasonic core driller (UTCD) was developed to meet the constraints of Small Bodies Exploration and Mars Sample Return Missions. The constraints in the design are size, weight, power, and axial loading. The ultrasonic transducer requires a relatively low axial load, which is one of the reasons this technology was chosen. The ultrasonic generator breadboard section can be contained within the 5x5x3 limits and weighs less than two pounds. Based on results attained the objectives for the first phase were achieved. A number of transducer probes were made and tested. One version only drills, and the other will actually provide a small core from a rock. Because of a more efficient transducer/probe, it will run at very low power (less than 5 Watts) and still drill/core. The prototype generator was built to allow for variation of all the performance-effecting elements of the transducer/probe/end effector, i.e., pulse, duty cycle, frequency, etc. The heart of the circuitry is what will be converted to a surface mounted board for the next phase, after all the parameters have been optimized and the microprocessor feedback can be installed.

  12. A model of weathering intensity for the Australian continent

    NASA Astrophysics Data System (ADS)

    Wilford, J.

    2013-12-01

    Regolith encompasses all weathered materials in the zone between the Earth's surface and fresh bedrock at depth. This weathered zone includes the soil, which may constitute the whole of the regolith profile or represent only its upper part. Important hydrological and biogeochemical processes operate within the regolith, including the infiltration and storage of near-surface water and nutrients, which sustain agricultural productivity. The degree to which the regolith is weathered (or its weathering intensity) is intrinsically linked to the factors involved in soil formation including parent material, climate, topography, biota and time. The degree to which the bedrock or sediments are weathered has a significant effect on the nature and distribution of regolith materials. There is commonly a strong correlation between weathering intensity and the degree of soil development as well as the depth of the weathering front. Changes in weathering intensity correspond to changes in the geochemical and physical properties of bedrock, ranging from essentially unweathered parent materials through to intensely weathered and leached regolith where all traits of the original protolith (original unweathered rock) are overprinted or lost altogether. With increasing weathering intensity we see mineral and geochemical convergence to more resistant secondary weathered materials including clay, silica, and various oxides. A weathering intensity index (WII) over the Australian continent has been developed at a 100 m resolution using two regression models based on airborne gamma-ray spectrometry imagery and the Shuttle Radar Topography Mission (SRTM) elevation data. Airborne gamma-ray spectrometry measures the concentration of three radioelements -- potassium (K), thorium (Th) and uranium (U) at the Earth's surface. The total gamma-ray flux (dose) is also calculated based on the weighted additions of the three radioelements. In general K is leached with increasing weathering whereas Th

  13. Draft Genome Sequence of Ensifer adhaerens M78, a Mineral-Weathering Bacterium Isolated from Soil.

    PubMed

    Wang, Yuanli; Chen, Wei; He, Linyan; Wang, Qi; Sheng, Xia-Fang

    2016-01-01

    Ensifer adhaerens M78, a bacterium isolated from soil, can weather potash feldspar and release Fe, Si, and Al from rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain M78, which may facilitate a better understanding of the molecular mechanism involved in mineral weathering by the bacterium. PMID:27609930

  14. Polygonal cracks in bedrock on Earth and Mars: Implications for weathering

    NASA Astrophysics Data System (ADS)

    Chan, Marjorie A.; Yonkee, W. Adolph; Netoff, Dennis I.; Seiler, Winston M.; Ford, Richard L.

    2008-03-01

    Polygonal crack systems with domal microrelief imaged by the Mars Exploration Rover (MER) Opportunity show remarkable similarity to terrestrial crack systems developed on outcrop surfaces. Study of Jurassic Navajo Sandstone surfaces show development of crack systems in relatively isotropic host rock as a result of tensile weathering stresses. These terrestrial analogs are utilized to understand potential weathering processes on Mars.

  15. Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.

    PubMed

    Norris, Richard D; Norris, James M; Lorenz, Ralph D; Ray, Jib; Jackson, Brian

    2014-01-01

    The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice. PMID:25162535

  16. DOPPLER WEATHER SYSTEM

    SciTech Connect

    Berlin, Gary J.

    2002-08-05

    The SRS Doppler Weather System consists of a Doppler Server, A Master Server (also known as the Weather Server), several Doppler Slave Servers, and client-side software program called the Doppler Radar Client. This system is used to display near rel-time images taken from the SRS Weather Center's Doppler Radar computer. The Doppler Server is software that resides on the SRS Doppler Computer. It gathers raw data, 24-bit color weather images via screen scraping ever five minutes as requested by the Master Server. The Doppler Server then reduces the 24-bit color images to 8-bit color using a fixed color table for analysis and compression. This preserves the fidelity of the image color and arranges the colors in specific order for display. At the time of color reduction, the white color used for the city names on the background images are remapped to a different index (color) of white that the white on the weather scale. The Weather Server places a time stamp on the image, then compresses the image and passes it to all Doppler Slave servers. Each of the Doppler Slave servers mainitain a circular buffer of the eight most current images representing the last 40 minutes of weather data. As a new image is added, the oldest drops off. The Doppler Radar Client is an optional install program for any site-wide workstation. When a Client session is started, the Client requests Doppler Slave server assignment from the Master Server. Upon its initial request to the Slave Server, the Client obtains all eight current images and maintains its own circular buffer, updating its images every five minutes as the Doppler Slave is updated. Three background reference images are stored as part of the Client. The Client brings up the appropriate background image, decompresses the doppler data, and displays the doppler data on the background image.

  17. DOPPLER WEATHER SYSTEM

    Energy Science and Technology Software Center (ESTSC)

    2002-08-05

    The SRS Doppler Weather System consists of a Doppler Server, A Master Server (also known as the Weather Server), several Doppler Slave Servers, and client-side software program called the Doppler Radar Client. This system is used to display near rel-time images taken from the SRS Weather Center's Doppler Radar computer. The Doppler Server is software that resides on the SRS Doppler Computer. It gathers raw data, 24-bit color weather images via screen scraping ever fivemore » minutes as requested by the Master Server. The Doppler Server then reduces the 24-bit color images to 8-bit color using a fixed color table for analysis and compression. This preserves the fidelity of the image color and arranges the colors in specific order for display. At the time of color reduction, the white color used for the city names on the background images are remapped to a different index (color) of white that the white on the weather scale. The Weather Server places a time stamp on the image, then compresses the image and passes it to all Doppler Slave servers. Each of the Doppler Slave servers mainitain a circular buffer of the eight most current images representing the last 40 minutes of weather data. As a new image is added, the oldest drops off. The Doppler Radar Client is an optional install program for any site-wide workstation. When a Client session is started, the Client requests Doppler Slave server assignment from the Master Server. Upon its initial request to the Slave Server, the Client obtains all eight current images and maintains its own circular buffer, updating its images every five minutes as the Doppler Slave is updated. Three background reference images are stored as part of the Client. The Client brings up the appropriate background image, decompresses the doppler data, and displays the doppler data on the background image.« less

  18. Global CO2-consumption by chemical weathering: What is the contribution of highly active weathering regions?

    NASA Astrophysics Data System (ADS)

    Hartmann, Jens; Jansen, Nils; Dürr, Hans H.; Kempe, Stephan; Köhler, Peter

    2010-05-01

    CO2-consumption by chemical weathering of silicates and resulting silicate/carbonate weathering ratios influences the terrestrial lateral inorganic carbon flux to the ocean and long-term climate changes. However, little is known of the spatial extension of highly active weathering regions and their proportion of global CO2-consumption. As those regions may be of significant importance for global climate change, global CO2-consumption is calculated here at high resolution, to adequately represent them. In previous studies global CO2-consumption is estimated using two different approaches: i) a reverse approach based on hydrochemical fluxes from large rivers and ii) a forward approach applying spatially explicit a function for CO2-consumption. The first approach results in an estimate without providing a spatial resolution for highly active regions and the second approach applied six lithological classes while including three sediment classes (shale, sandstone and carbonate rock) based at a 1° or 2° grid resolution. It remained uncertain, if the applied lithological classification schemes represent adequately CO2-consumption from sediments on a global scale (as well as liberation of other elements like phosphorus or silicon by chemical weatheirng). This is due to the large variability of sediment properties, their diagenetic history and the contribution from carbonates apparent in silicate dominated lithological classes. To address these issues, a CO2-consumption model, trained at high-resolution data, is applied here to a global vector based lithological map with 15 lithological classes. The calibration data were obtained from areas representing a wide range of weathering rates. Resulting global CO2-consumption by chemical weathering is similar to earlier estimates (237 Mt C a-1) but the proportion of silicate weathering is 63%, and thus larger than previous estimates (49 to 60%). The application of the enhanced lithological classification scheme reveals that it

  19. New weather index

    NASA Astrophysics Data System (ADS)

    Scientists at the National Oceanic and Atmospheric Administration (NOAA) and the University of Delaware have refined the wind-chill factor, a common measurement of weather discomfort, into a new misery register called the weather stress index. In addition to the mix of temperature and wind speed data used to calculate wind chill, the recipe for the index adds two new ingredients—humidity and a dash of benchmark statistics—to estimate human reaction to weather conditions. NOAA says that the weather stress index estimates human reaction to weather conditions and that the reaction depends on variations from the ‘normal’ conditions in the locality involved.Discomfort criteria for New Orleans, La., and Bismarck, N.D., for example, differ drastically. According to NOAA, when it's the middle of winter and it's -10°C with a relative humidity of 80% and 24 km/h winds, persons in New Orleans would be highly stressed while those in Bismarck wouldn't bat an eye.

  20. [Weather, climate and health].

    PubMed

    Banić, M; Plesko, N; Plesko, S

    1999-01-01

    The notion of complex influence of atmospheric conditions on modem human population, especially the relationship between weather, climate and human healths, has actuated the World Meteorological Organisation to commemorate the coming into force, on March 23, 1950, of the Convention of WMO and this year to celebrate this day by focusing on theme of current interest--"Weather, climate and health". In the light of this, the authors of this paper reveal the results of recent studies dealing with influence of sudden and short-term changes in weather and climate on human health, and future expected climate changes due to "greenhouse" effect, increase in global temperature and tropospheric ozone depletion, as well. Special attention is given to climate shifts due to ENSO (El Niño/Southern Oscillation) phenomenon because of its great impact on human society and epidemics of certain infectious diseases. The results of biometeorological studies dealing with complex influence of daily weather changes on incidence of certain diseases in Croatia have also been presented. In addition, the authors have stated their own view and opinion in regard to future biometeorlogical studies in Croatia in order to achieve better understanding of influence of climate and weather changes on human health, and help prevention of mortality and morbidity related to chronic noninfectious diseases. PMID:19658377

  1. Weather from the Stratosphere?

    NASA Technical Reports Server (NTRS)

    Baldwin, Mark P.; Thompson, David W. J.; Shuckburgh, Emily F.; Norton, Warwick A.; Gillett, Nathan P.

    2006-01-01

    Is the stratosphere, the atmospheric layer between about 10 and 50 km, important for predicting changes in weather and climate? The traditional view is that the stratosphere is a passive recipient of energy and waves from weather systems in the underlying troposphere, but recent evidence suggests otherwise. At a workshop in Whistler, British Columbia (1), scientists met to discuss how the stratosphere responds to forcing from below, initiating feedback processes that in turn alter weather patterns in the troposphere. The lowest layer of the atmosphere, the troposphere, is highly dynamic and rich in water vapor, clouds, and weather. The stratosphere above it is less dense and less turbulent (see the figure). Variability in the stratosphere is dominated by hemispheric-scale changes in airflow on time scales of a week to several months. Occasionally, however, stratospheric air flow changes dramatically within just a day or two, with large-scale jumps in temperature of 20 K or more. The troposphere influences the stratosphere mainly through atmospheric waves that propagate upward. Recent evidence shows that the stratosphere organizes this chaotic wave forcing from below to create long-lived changes in the stratospheric circulation. These stratospheric changes can feed back to affect weather and climate in the troposphere.

  2. New weather radar coming

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    What would you call the next generation of radar for severe weather prediction? NEXRAD, of course. A prototype for the new system was recently completed in Norman, Okla., and by the early 1990s up to 195 stations around the United States will be tracking dangerous weather and sending faster, more accurate, and more detailed warnings to the public.NEXRAD is being built for the Departments of Commerce, Transportation, and Defense by the Unisys Corporation under a $450 million contract signed in December 1987. Th e system will be used by the National Weather Service, the Federal Aviation Administration (FAA), and the U.S. Air Force and Navy. The NEXRAD radar tower in Norman is expected to be operational in October.

  3. Spaceborne weather radar

    NASA Technical Reports Server (NTRS)

    Meneghini, Robert; Kozu, Toshiaki

    1990-01-01

    The present work on the development status of spaceborne weather radar systems and services discusses radar instrument complementarities, the current forms of equations for the characterization of such aspects of weather radar performance as surface and mirror-image returns, polarimetry, and Doppler considerations, and such essential factors in spaceborne weather radar design as frequency selection, scanning modes, and the application of SAR to rain detection. Attention is then given to radar signal absorption by the various atmospheric gases, rain drop size distribution and wind velocity determinations, and the characteristics of clouds, as well as the range of available estimation methods for backscattering, single- and dual-wavelength attenuation, and polarimetric and climatological characteristics.

  4. Space Weather Workshop

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.

    2004-01-01

    This workshop will focus on what space weather is about and its impact on society. An overall picture will be "painted" describing the Sun's influence through the solar wind on the near-Earth space environment, including the aurora, killer electrons at geosynchronous orbit, million ampere electric currents through the ionosphere and along magnetic field lines, and the generation of giga-Watts of natural radio waves. Reference material in the form of Internet sites will be provided so that teachers can discuss space weather in the classroom and enable students to learn more about this topic.

  5. Quantification of rock fall processes on recently deglaciated rock slopes, Gepatsch glacier, Tyrol (Austria)

    NASA Astrophysics Data System (ADS)

    Vehling, Lucas; Rohn, Joachim; Moser, Michael

    2014-05-01

    The recently deglaciated area in alpine glacier forefields is characterized by intensified mass movement processes in particular debris flows, shallow landslides and rockfalls. Due to enhanced geomorphic activity, rock slopes adjacent to shrinking glaciers contribute in a substantial way to the sediment budget. In this study, direct measurements of rock fall intensity are conducted by rock fall collector nets and natural sediment traps. The study area is a high mountain (1750-3520m a.s.l) catchment, which is recently about 30% glaciated. The extension of the Gepatsch glacier has been reducing since the little ice age maximum in the mid of the 19th century with an average annual shrinking rate of a few decameters at its tongue. The first results of the direct measurements demonstrate that on the recently deglaciated rock slopes, rock fall intensity is at least one order of magnitude higher (2,38-6,64 g/m2/d - corresponding backweathering rate: 0,3-0,9 mm/a) than on rock slopes which had has ice free since the last Pleistocene deglaciation (0,04-0,38 g/m2/d - backweathering rate: 0,005-0,05 mm/a). The highest rock fall intensity is attributed to the recent deglaciated rock slopes which are located close to larger fault systems (>60 g/m2/d - backweathering rate: >8 mm/a). Rock fall intensity shows also considerable intra-annual variations which are related to cold climate weathering processes and rainstorm activity.

  6. A Rock Encyclopedia That Includes Rock Samples.

    ERIC Educational Resources Information Center

    Laznicka, Peter

    1981-01-01

    Described is a rock encyclopedia combining rock sample sets and encyclopedic word and picture entries which can be used as a realistic information resource for independent study or as a part of a course. (JT)

  7. High potential for weathering and climate effects of non-vascular vegetation in the Late Ordovician

    NASA Astrophysics Data System (ADS)

    Porada, P.; Lenton, T. M.; Pohl, A.; Weber, B.; Mander, L.; Donnadieu, Y.; Beer, C.; Pöschl, U.; Kleidon, A.

    2016-07-01

    It has been hypothesized that predecessors of today's bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO2 concentration and contributing to climate cooling and an interval of glaciations. Studies that try to quantify the enhancement of weathering by non-vascular vegetation, however, are usually limited to small areas and low numbers of species, which hampers extrapolating to the global scale and to past climatic conditions. Here we present a spatially explicit modelling approach to simulate global weathering by non-vascular vegetation in the Late Ordovician. We estimate a potential global weathering flux of 2.8 (km3 rock) yr-1, defined here as volume of primary minerals affected by chemical transformation. This is around three times larger than today's global chemical weathering flux. Moreover, we find that simulated weathering is highly sensitive to atmospheric CO2 concentration. This implies a strong negative feedback between weathering by non-vascular vegetation and Ordovician climate.

  8. New Rock Physical Properties Assessments From the Mars Exploration Rover Rock Abrasion Tool (RAT).

    NASA Astrophysics Data System (ADS)

    Bartlett, P. W.; Basso, B.; Kusack, A.; Wilson, J.; Zacny, K.

    2005-12-01

    The Rock Abrasion Tool (RAT) serves as the sample preparation device on the Mars Exploration Rovers (MER) science payload. The RAT grinds a circular area 45 millimeter in diameter, and on the order of a few millimeters deep, into a rock face. This process removes surface fines and weathered layers in preparation for imaging and spectral observations of the rock. As of September 2005, 15 grinding operations have been performed at Gusev Crater and 26 at Meridiani Planum. Since the RAT performs a mechanical operation on a rock, deductions can be made via the RAT's engineering data about the rock's physical properties. For each grinding operation, the energy consumed while grinding is converted to provide a physically relevant Specific Grind Energy (SGE) in terms of Joules per cubic millimeter of rock removed. The calculation is performed over the last 0.25 millimeter of a grinding operation, where it is possible, by taking measurements from Microscopic Imager images of the abraded area, to make an accurate estimate of the volume of rock removed. Progress is presented on recent refinement of the SGE calculation methods including decoupling of artifacts. Environmental factors and differing parameters used to command the RAT operations are among the key artifacts recently analyzed. Progress is also presented on further characterization of the dynamics and wear mechanics involved in the grinding process, and how they influence SGE. A library of Earth rocks has been assembled and it is being used with the RAT Engineering Model to create a set of similar SGE data products that can be compared to Mars rocks in order to contribute to physical properties assessments of the Mars rocks. Initial results indicate that the Martian rocks are analogous to a range of Earth rocks, from gypsum to low-strength basalt in terms of grindability; however, caution needs to be exercised in making a direct comparison of grinding energies. This is because the grindability of rocks was found to

  9. Effects of chemical weathering on infrared spectra of Columbia River Basalt and spectral interpretations of martian alteration

    NASA Astrophysics Data System (ADS)

    Michalski, Joseph R.; Kraft, Michael D.; Sharp, Thomas G.; Christensen, Philip R.

    2006-08-01

    We investigated the mineralogy of basalt weathering rinds and fresh basaltic rocks using visible/near-infrared (VNIR) ( λ = 0.4-2.5 μm) and thermal emission ( λ = 6-30 μm) spectroscopy to 1) constrain the effects of chemical weathering on rock spectra, and 2) further understand the context of infrared spectra of Mars, which may contain evidence for weathered rocks and particulates derived from them. VNIR spectra of weathered rock surfaces are generally redder and brighter than fresh surfaces. Thermal infrared spectra of weathered basalts show evidence for aluminous opal and clay minerals (or clay precursor mineraloids) in natural surfaces. Supporting VNIR observations generally do not show the same evidence for neoformed clays or silica because of their textural occurrence as thin coatings and microfracture-fill, and possibly due to poor crystallinity of the aluminosilicate weathering products in this context. Spectral trends observed at Mars, such as the detection of low to moderate (10-25%) abundances of silica and clay that are observed in the thermal infrared but not in the VNIR, are therefore consistent with trends observed for natural rock surfaces in the laboratory. The combined use of thermal infrared and VNIR suggest that vast areas of martian dark regions contain sandy-rocky basaltic materials with weathering rinds and thin coatings that could have formed in conditions of relatively low water/rock ratios.

  10. Accessing Space Weather Information

    NASA Astrophysics Data System (ADS)

    Morrison, D.; Weiss, M.; Immer, E. A.; Patrone, D.; Potter, M.; Barnes, R. J.; Colclough, C.; Holder, R.

    2009-12-01

    To meet the needs of our technology based society, space weather forecasting needs to be advanced and this will entail collaboration amongst research, military and commercial communities to find new ways to understand, characterize, and forecast. In this presentation VITMO, the Virtual Ionosphere-Thermosphere-Mesosphere Observatory will be used as a prototype for a generalized system as a means to bring together a set of tools to access data, models and online collaboration tools to enable rapid progress. VITMO, available at http://vitmo.jhuapl.edu/, currently provides a data access portal for researchers and scientists to enable finding data products as well as access to tools and models. To further the needs of space weather forecasters, the existing VITMO data holdings need to be expanded to provide additional datasets as well as integrating relevant models and model output. VITMO can easily be adapted for the Space Weather domain in its entirety. In this presentation, we will demonstrate how VITMO and the VITMO architecture can be utilized as a prototype in support of integration of Space Weather forecasting tools, models and data.

  11. Weather Specialist (AFSC 25120).

    ERIC Educational Resources Information Center

    Air Univ., Gunter AFS, Ala. Extension Course Inst.

    This correspondence course is designed for self-study to help military personnel to attain the rating of weather specialist. The course is organized in three volumes. The first volume, containing seven chapters, covers background knowledge, meteorology, and climatology. In the second volume, which also contains seven chapters, surface…

  12. Silam Irrusia (Weather Conditions).

    ERIC Educational Resources Information Center

    Brown, Emily Ivanoff

    This illustrated reader in Inupiaq Athabascan is intended for use in a bilingual education setting and is geared toward readers, especially schoolchildren, who have a good grasp of the language. It consists of a story about traditional Inupiaq beliefs concerning the weather, stars, etc. (AMH)

  13. Microbial Weathering of Olivine

    NASA Technical Reports Server (NTRS)

    McKay, D. S.; Longazo, T. G.; Wentworth, S. J.; Southam, G.

    2002-01-01

    Controlled microbial weathering of olivine experiments displays a unique style of nanoetching caused by biofilm attachment to mineral surfaces. We are investigating whether the morphology of biotic nanoetching can be used as a biosignature. Additional information is contained in the original extended abstract.

  14. Weathering the Double Whammy.

    ERIC Educational Resources Information Center

    Wellman, Jane V.

    2002-01-01

    Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the institution's…

  15. Weather and Flight Testing

    NASA Technical Reports Server (NTRS)

    Wiley, Scott

    2007-01-01

    This viewgraph document reviews some of the weather hazards involved with flight testing. Some of the hazards reviewed are: turbulence, icing, thunderstorms and winds and windshear. Maps, pictures, satellite pictures of the meteorological phenomena and graphs are included. Also included are pictures of damaged aircraft.

  16. Worldwide Marine Weather Broadcasts.

    ERIC Educational Resources Information Center

    Department of the Navy, Washington, DC.

    This publication is a source of marine weather broadcast information in all areas of the world where such service is provided. This publication was designed for the use of U.S. naval and merchant ships. Sections 1 through 4 contain details of radio telegraph, radio telephone, radio facsimile, and radio teleprinter transmissions, respectively. The…

  17. Dress for the Weather

    ERIC Educational Resources Information Center

    Glen, Nicole J.; Smetana, Lara K.

    2010-01-01

    "If someone were traveling to our area for the first time during this time of year, what would you tell them to bring to wear? Why?" This question was used to engage students in a guided-inquiry unit about how climate differs from weather. In this lesson, students explored local and national data sets to give "travelers" advice when preparing for…

  18. Rainy Weather Science.

    ERIC Educational Resources Information Center

    Reynolds, Karen

    1996-01-01

    Presents ideas on the use of rainy weather for activities in the earth, life, and physical sciences. Topics include formation and collision of raindrops, amount and distribution of rain, shedding of water by plants, mapping puddles and potholes, rainbow formation, stalking storms online, lightning, and comparing particles in the air before and…

  19. Weather, Climate, and You.

    ERIC Educational Resources Information Center

    Blai, Boris, Jr.

    Information from the American Institute of Medical Climatologists on human responses to weather and climatic conditions, including clouds, winds, humidity, barometric pressure, heat, cold, and other variables that may exert a pervasive impact on health, behavior, disposition, and the level of efficiency with which individuals function is reviewed.…

  20. Satellite Weather Watch.

    ERIC Educational Resources Information Center

    Summers, R. Joe

    1982-01-01

    Describes an inexpensive (about $1,500) direct-readout ground station for use in secondary school science/mathematics programs. Includes suggested activities including, among others, developing map overlays, operating station equipment, interpreting satellite data, developing weather forecasts, and using microcomputers for data storage, orbit…

  1. Weather in Motion.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    The ATS-111 weather satellite, launched on November 18, 1967, in a synchronous earth orbit 22,000 miles above the equator, is described in this folder. The description is divided into these topics: the satellite, the camera, the display, the picture information, and the beneficial use of the satellite. Photographs from the satellite are included.…

  2. Effects of climate on chemical weathering in watersheds

    USGS Publications Warehouse

    White, A.F.; Blum, A.E.

    1995-01-01

    Climatic effects on chemical weathering are evaluated by correlating variations in solute concentrations and fluxes with temperature, precipitation, runoff, and evapotranspiration (ET) for a worldwide distribution of sixty-eight watersheds underlain by granitoid rock types. Stream solute concentrations are strongly correlated with proportional ET loss, and evaporative concentration makes stream solute concentrations an inapprorpiate surrogate for chemical weathering. Chemical fluxes are unaffected by ET, and SiO2 and Na weathering fluxes exhibit systematic increases with precipitation, runoff, and temperature. However, warm and wet watersheds produce anomalously rapid weathering rates. A proposed model that provides an improved prediction of weathering rates over climatic extremes is the product of linear precipitation and Arrhenius temperature functions. The resulting apparent activation energies based on SiO2 and Na fluxes are 59.4 and 62.5 kJ.mol-1, respectively. The coupling between temperature and precipitation emphasizes the importance of tropical regions in global silicate weathering fluxes, and suggests it is not representative to use continental averages for temperature and precipitation in the weathering rate functions of global carbon cycling and climatic change models. Fluxes of K, Ca, and Mg exhibit no climatic correlation, implying that other processes, such as ion exchange, nutrient cycling, and variations in lithology, obscure any climatic signal. -from Authors

  3. Weather impacts on space operations

    NASA Astrophysics Data System (ADS)

    Madura, J.; Boyd, B.; Bauman, W.; Wyse, N.; Adams, M.

    The efforts of the 45th Weather Squadron of the USAF to provide weather support to Patrick Air Force Base, Cape Canaveral Air Force Station, Eastern Range, and the Kennedy Space Center are discussed. Its weather support to space vehicles, particularly the Space Shuttle, includes resource protection, ground processing, launch, and Ferry Flight, as well as consultations to the Spaceflight Meteorology Group for landing forecasts. Attention is given to prelaunch processing weather, launch support weather, Shuttle launch commit criteria, and range safety weather restrictions. Upper level wind requirements are examined. The frequency of hourly surface observations with thunderstorms at the Shuttle landing facility, and lightning downtime at the Titan launch complexes are illustrated.

  4. Space Weather Forecasting at NASA GSFC Space Weather Research Center

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Kuznetsova, M. M.; Pulkkinen, A.; Maddox, M. M.; Taktakishvili, A.; Mays, M. L.; Chulaki, A.; Lee, H.; Hesse, M.; Evans, R. M.; Berrios, D.; Mullinix, R.

    2012-12-01

    The NASA GSFC Space Weather Research Center (http://swrc.gsfc.nasa.gov) is committed to providing research forecasts and notifications to address NASA's space weather needs - in addition to its critical role in space weather education. We provide a host of services including spacecraft anomaly resolution, historical impact analysis, real-time monitoring and forecasting, tailored space weather alerts and products, weekly summaries and reports, and most recently - video casts. In this presentation, we will focus on how near real-time data (both in space and on ground), in combination with modeling capabilities and an innovative dissemination system called the Integrated Space Weather Analysis System (iSWA http://iswa.gsfc.nasa.gov), enable space weather forecasting and quality space weather products provided by our Center. A few critical near real-time data streams for space weather forecasting will be identified and discussed.

  5. Physico-Mechanical Characteristics of Freeze-Thaw Weathered Gneiss based on Accelerated Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Um, J. G.

    2014-12-01

    An experimental study of physical weathering was performed on fresh and slightly weathered gneiss samples from the Wonju area of South Korea. The study investigated changes in the physico-mechanical properties of these samples during accelerated laboratory-based weathering, including analyses of microfracture formation. The deteriorated samples used in the study were subjected to 100-150 freeze-thaw cycles, with index properties and microfracture geometries measured between each cycle. Each complete freeze-thaw cycle lasted 24 hours, and consisted of 2 hours of saturation in a vacuum chamber, 8 hours of freezing at -21°C ±1°C, and 14 hours of thawing at room temperature. Specific gravity and seismic velocity values were negatively correlated with the number of freeze-thaw cycles, whereas absorption values tended to increase. The amount of deterioration of the rock samples was dependent on the degree of weathering of the rock prior to the start of the analysis. Absorption, specific gravity, and seismic velocity values can be used to infer the amount of physical weathering experienced by a gneiss in the study area. The sizes and density of microfracture in the rock specimens varied with the number of freeze-thaw cycles. It was found that box fractal dimensions can be used to quantify the formation and propagation of microfracture in the samples. In addition, these box fractal dimensions can be used as a weathering index for the mid- and long-term prediction of rock weathering. The present results indicate that accelerated-weathering analysis can provide a detailed overview of the weathering characteristics of deteriorated rocks.

  6. Initial effects of vegetation on Hawaiian basalt weathering rates

    SciTech Connect

    Cochran, M.F.; Berner, R.A. )

    1992-01-01

    Weathering of Ca and Mg silicates on land and ensuing precipitation and burial of Ca and Mg carbonates in marine sediments is the principal sink for carbon dioxide from the atmosphere/ocean system on geologic time scales. Model calculations of ancient atmospheric CO[sub 2] partial pressure depend strongly on the authors assumptions about the enhancement of silicate weathering rates first by primitive terrestrial biota, then by the appearance and evolution of the vascular plants. Aa and pahoehoe basalts were collected from Mauna Loa and Kilauea volcanoes on the island of Hawaii. Flows ranged in age (one year to several thousand years) and in ambient climate. Where possible, each flow was sampled beneath a suite of current plant covers: none, lichens, and higher plants. Rocks were embedded in epoxy to preserve the plant-rock interface, then sectioned and subjected to electron probe microanalysis. During initial weathering, vascular plants appeared to promote congruent dissolution of minerals (particularly olivine and Ca-rich plagioclase) and glass near the surfaces of underlying basalts. In the neighborhood of roots, primary cracks widened with time into networks of open channels. This effect was observed prior to the formation of measurable leached zones in exterior grains and prior to the appearance of secondary minerals. As a result, initial mass loss from young, plant-covered basalts appeared to be up to one or more orders of magnitude greater than from bare-rock controls. Despite earlier reports of substantial enhancement of Hawaiian basalt weathering rates by the lichen Stereocaulon vulcani, weathering observed beneath this lichen was comparable to that of unvegetated rocks.

  7. Weatherization Works: An interim report of the National Weatherization Evaluation

    SciTech Connect

    Brown, M.A.; Berry, L.G.; Kinney, L.F.

    1993-11-01

    The National Weatherization Evaluation is the first comprehensive evaluation of the Weatherization Assistance Program since 1984. The evaluation was designed to accomplish the following goals: Estimate energy savings and cost effectiveness; Assess nonenergy impacts; Describe the weatherization network; Characterize the eligible population and resources; and Identify factors influencing outcomes and opportunities for the future. As a national program, weatherization incorporates considerable diversity due to regional differences. Therefore, evaluation results are presented both in aggregate and for three climate regions: cold, moderate and hot.

  8. Chemical weathering of granite under acid rainfall environment, Korea

    NASA Astrophysics Data System (ADS)

    Lee, Seung Yeop; Kim, Soo Jin; Baik, Min Hoon

    2008-08-01

    Chemical weathering was investigated by collecting samples from five selected weathering profiles in a high elevation granitic environment located in Seoul, Korea. The overall changes of chemistry and mineralogical textures were examined reflecting weathering degrees of the samples, using polarization microscopy, X-ray diffraction (XRD), electron probe micro analysis (EPMA), X-ray fluorescence spectroscopy (XRF), and inductively coupled plasma-mass spectroscopy (ICP-MS). The chemical distribution in the weathering profiles shows that few trace elements are slightly immobile, whereas most major (particularly Ca and Na) and trace elements are mobile from the beginning of the granite weathering. On the other hand, there were mineralogical changes initiated from a plagioclase breakdown, which shows a characteristic circular dissolved pattern caused by a preferential leaching of Ca cation along grain boundaries and zoning. The biotite in that region is also supposed to be sensitive to exterior environmental condition and may be easily dissolved by acidic percolated water. As a result, it seems that some rock-forming minerals in the granitic rock located in Seoul are significantly unstable due to the environmental condition of acidic rainfall and steep slopes, where they are susceptible to be dissolved incongruently leading some elements to be highly depleted.

  9. Provenance control on chemical indices of weathering (Taiwan river sands)

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Resentini, Alberto

    2016-05-01

    Geochemical parameters obtained from the analysis of sediments and sedimentary rocks are widely used to infer weathering and paleo-weathering conditions in source areas. Chemical indices of weathering, however, may not reflect weathering only, or even principally. The concentration of chemical elements in terrigenous sediments is constrained by the original mineralogy of source rocks, and is thus provenance-dependent. Moreover, the mineralogy and consequently the geochemistry of sediments may undergo substantial modifications by diverse physical processes during transport and deposition, including recycling and hydraulic sorting by size, density or shape, and/or by chemical dissolution and precipitation during diagenesis. Around the island of Taiwan, temperature and rainfall are consistently high and relatively homogeneous, and no significant correlation is observed between geochemical and climatic parameters. Physical erosion, fostered by landslides induced by frequent earthquakes and typhoons, prevails because of high relief and extreme rates of tectonic uplift. In such a dynamic orogenic setting, all chemical indices of weathering are controlled principally by the geology of source terranes. Sedimentaclastic and metasedimentaclastic sands carried by western Taiwan rivers draining the pro-wedge display the strongest depletion in Na, Ca, Mg and Sr relative to average upper continental crust, and no depletion or even enrichment in K, Rb and Ba. Low WIP indices reflect erosion of phyllosilicate-dominated rocks in the Slate Belt and extensive recycling of clastic rocks exposed in the Western Foothills. Instead, metamorphiclastic sands carried by eastern Taiwan rivers draining the retro-wedge show no depletion or even enrichment in Mg and Ca, and low CIA and PIA, reflecting contributions from the Tailuko Belt and Coastal Range. Volcaniclastic sands have the same CIA values of their andesitic source rocks (47 ± 1 versus 47 ± 7), indicating that weathering is

  10. Spirit Discovers New Class of Igneous Rocks

    NASA Technical Reports Server (NTRS)

    2006-01-01

    During the past two-and-a-half years of traversing the central part of Gusev Crater, NASA's Mars Exploration Rover Spirit has analyzed the brushed and ground-into surfaces of multiple rocks using the alpha particle X-ray spectrometer, which measures the abundance of major chemical elements. In the process, Spirit has documented the first example of a particular kind of volcanic region on Mars known as an alkaline igneous province. The word alkaline refers to the abundance of sodium and potassium, two major rock-forming elements from the alkali metals on the left-hand side of the periodic table.

    All of the relatively unaltered rocks -- those least changed by wind, water, freezing, or other weathering agents -- examined by Spirit have been igneous, meaning that they crystallized from molten magmas. One way geologists classify igneous rocks is by looking at the amount of potassium and sodium relative to the amount of silica, the most abundant rock-forming mineral on Earth. In the case of volcanic rocks, the amount of silica present gives scientists clues to the kind of volcanism that occurred, while the amounts of potassium and sodium provide clues about the history of the rock. Rocks with more silica tend to erupt explosively. Higher contents of potassium and sodium, as seen in alkaline rocks like those at Gusev, may indicate partial melting of magma at higher pressure, that is, deeper in the Martian mantle. The abundance of potassium and sodium determines the kinds of minerals that make up igneous rocks. If igneous rocks have enough silica, potassium and sodium always bond with the silica to form certain minerals.

    The Gusev rocks define a new chemical category not previously seen on Mars, as shown in this diagram plotting alkalis versus silica, compiled by University of Tennessee geologist Harry McSween. The abbreviations 'Na2O' and 'K2O' refer to oxides of sodium and potassium. The abbreviation 'SiO2' refers to silica. The abbreviation 'wt

  11. Weathering of Mars - Antarctic analog studies

    NASA Technical Reports Server (NTRS)

    Berkley, J. L.; Drake, M. J.

    1981-01-01

    Subaerial extrusion of lavas above permafrost is proposed as a possible weathering regime leading to the presence of Martian surface fines, and the characteristics of this process are examined through a study of the analogous altered terrestrial basalts from Antarctica. On the basis of mineralogical and petrological analyses of samples obtained from core cuttings recovered by the Dry Valley Drilling Program from rocks predominantly of an aklalic basalt-phonolite suite, it is found that in the absence of liquid water, weathering is geologically slow, and that zeolites predominate over clays as secondary mineral. Of the possible weathering processes proposed for Mars, it is concluded that both subaerial extrusion and subpermafrost intrusion of lavas involving liquid water would be less important volumetrically than the hydrothermal alteration of impact melt sheets if water were present during an intense phase of early bombardment, or than subsequent solid-gas alteration reactions. It is thus predicted that the present Martian fines should contain a major contribution from the ancient crust as typified by the southern cratered highlands, and a lesser contribution from the younger basaltic lavas.

  12. Bringing Weather into Your Classroom.

    ERIC Educational Resources Information Center

    Mogil, H. Michael

    1979-01-01

    Discusses meteorological resources available to classroom teachers. Describes in detail the National Oceanic and Atmospheric Administration (NOAA) Weather Radio and the A.M. Weather Show on Public Broadcasting Service (PBS). Includes addresses where teachers can get more information. (MA)

  13. Winter Weather Frequently Asked Questions

    MedlinePlus

    ... Planning Information on Specific Types of Emergencies Winter Weather Frequently Asked Questions Language: English Español (Spanish) Recommend ... I do if I get stranded in cold weather? Tie a brightly colored cloth to the antenna ...

  14. Geography and Weather: Mountain Meterology.

    ERIC Educational Resources Information Center

    Mogil, H. Michael; Collins, H. Thomas

    1990-01-01

    Provided are 26 ideas to help children explore the effects of mountains on the weather. Weather conditions in Nepal and Colorado are considered separately. Nine additional sources of information are listed. (CW)

  15. Astrobiological Implications of Rock Varnish in Tibet

    NASA Astrophysics Data System (ADS)

    Krinsley, David; Dorn, Ronald I.; DiGregorio, Barry

    2009-08-01

    The study of terrestrial geomicrobiology and its relationship to rock weathering processes is an essential tool in developing analogues for similar processes that may have occurred on Mars. Most studies of manganese-enhanced rock varnish have focused on samples taken from warm arid desert regions. Here, we examine samples obtained from eolian-abraded lava flows of the 4700-4800 m high Ashikule Basin in Tibet. Because it receives approximately 300 mm of precipitation annually, this site is nowhere near as dry as Atacama Desert locales. However, the dusty, sulfate-rich, high-altitude and high-UV flux environment of the Tibetan locale offers new insight into rock varnish formation processes in a terrestrial environment that displays some attributes similar to those expected on early Mars. Microprobe measurements reveal that Mn enhancements in varnish are two orders of magnitude above the dust source, but Fe is only enhanced by a factor of three. Manganese-enhancing bacterial forms are not abundant but are still approximately 3 times more common than in Mojave and Sonoran Desert varnishes. In addition to its occurrence in subaerial positions, Tibetan varnish also occurs in micron-scale "pods" enveloped by silica glaze and as remobilized constituents that have migrated into the underlying weathering rind. A lack of surficial Mn-rich varnish, therefore, might not imply the absence of varnish. In contrast to suggestions that silica glaze might be a good source of microbial fossils and a key to varnish formation, we did not observe any clear microfossil forms entombed in silica glaze; further, there is no gradation between varnish and silica glaze but only distinct contacts. %K Analogue, Astrobiology, Bacteria, Biomineralization, Desert varnish, Geomicrobiology, Life on Mars, Manganese enhancement, Rock coating, Rock varnish, Microstromatolite, Tibet, Weathering

  16. Rollerjaw Rock Crusher

    NASA Technical Reports Server (NTRS)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  17. Alteration of Lunar Rock Surfaces through Interaction with the Space Environment

    NASA Technical Reports Server (NTRS)

    Frushour, A. M.; Noble, S. K; Christoffersen, R.; Keller, L P.

    2014-01-01

    Space weathering occurs on all ex-posed surfaces of lunar rocks, as well as on the surfaces of smaller grains in the lunar regolith. Space weather-ing alters these exposed surfaces primarily through the action of solar wind ions and micrometeorite impact processes. On lunar rocks specifically, the alteration products produced by space weathering form surface coatings known as patina. Patinas can have spectral reflectance properties different than the underlying rock. An understanding of patina composition and thickness is therefore important for interpreting re-motely sensed data from airless solar system bodies. The purpose of this study is to try to understand the physical and chemical properties of patina by expanding the number of patinas known and characterized in the lunar rock sample collection.

  18. Weather Specialist/Aerographer's Mate.

    ERIC Educational Resources Information Center

    Chanute AFB Technical Training Center, IL.

    This course trains Air Force personnel to perform duties prescribed for weather specialists and aerographer's mates. Training includes meteorology, surface and ship observation, weather radar, operation of standard weather instruments and communications equipment, and decoding and plotting of surface and upper air codes upon standard maps and…

  19. Weather Fundamentals: Climate & Seasons. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes), describes weather patterns and cycles around the globe. The various types of climates around…

  20. Weather Folklore: Fact or Fiction?

    ERIC Educational Resources Information Center

    Jones, Gail; Carter, Glenda

    1995-01-01

    Integrating children's weather-related family folklore with scientific investigation can be an effective way to involve elementary and middle level students in lessons spanning the disciplines of science, geography, history, anthropology, and language arts. Describes weather folklore studies and examples of weather investigations performed with…

  1. Severe Weather Planning for Schools

    ERIC Educational Resources Information Center

    Watson, Barbara McNaught; Strong, Christopher; Bunting, Bill

    2008-01-01

    Flash floods, severe thunderstorms, and tornadoes occur with rapid onset and often no warning. Decisions must be made quickly and actions taken immediately. This paper provides tips for schools on: (1) Preparing for Severe Weather Emergencies; (2) Activating a Severe Weather Plan; (3) Severe Weather Plan Checklist; and (4) Periodic Drills and…

  2. Improved weather information and aviation

    NASA Technical Reports Server (NTRS)

    Hallahan, K.; Zdanys, V.

    1973-01-01

    The major impacts of weather forecasts on aviation are reviewed. Topics discussed include: (1) present and projected structure of American aviation, (2) weather problems considered particularly important for aviation, (3) projected needs for improved weather information by aviators, (4) safety and economics, and (5) future studies utilizing satellite meteorology.

  3. Whether weather affects music

    NASA Astrophysics Data System (ADS)

    Aplin, Karen L.; Williams, Paul D.

    2012-09-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London [Richardson, 2012]. Of course, an important part of what we see and hear is not only the people with whom we interact but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant because we are exposed to it directly and daily. The weather was a great source of inspiration for artists Claude Monet, John Constable, and William Turner, who are known for their scientifically accurate paintings of the skies [e.g., Baker and Thornes, 2006].

  4. Winter weather scorecard

    NASA Astrophysics Data System (ADS)

    Last fall's 3-month winter weather prediction by National Weather Service (NWS) forecasters was not terrific, but it was not too far off the mark, either. A comparison of the predicted temperatures and precipitation (Eos, December 25, 1984, p. 1241) to the observed conditions (see Figures 1 and 2) during the months of December, January, and February shows that the forecasters were generally correct where they were most confident in their predictions.According to Donald Gilman, chief of the Predictions Branch at NWS's National Climate Analysis Center, the overall temperature forecast was probably better than that for precipitation. “The temperature forecast was pretty good in the West,” said Gilman. “East of the Mississippi, however, was a mixed picture.”

  5. Scorecard on weather predictions

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    No matter that several northern and eastern states were pelted by snow and sleet early in March, as far as longterm weather forecasters are concerned, winter ended on February 28. Now is the time to review their winter seasonal forecasts to determine how accurate were those predictions issued at the start of winter.The National Weather Service (NWS) predicted on November 27, 1981, that the winter season would bring colder-than-normal temperatures to the eastern half of the United States, while temperatures were expected to be higher than normal in the westernmost section (see Figure 1). The NWS made no prediction for the middle of the country, labeling the area ‘indeterminate,’ or having the same chance of experiencing above-normal temperatures as below-normal temperatures, explained Donald L. Gilman, chief of the NWS long-range forecasting group.

  6. Kazakhstan Space Weather Initiative

    NASA Astrophysics Data System (ADS)

    Kryakunova, Olga

    2012-07-01

    Kazakhstan experimental complex is a center of experimental study of space weather. This complex is situated near Almaty, Kazakhstan and includes experimental setup for registration of cosmic ray intensity (neutron monitor) at altitude of 3340 m above sea level, geomagnetic observatory and setup for registration of solar flux density with frequency of 1 and 3 GHz with 1 second time resolution. Results of space environment monitoring in real time are accessible via Internet. This experimental information is used for space weather investigations and different cosmic ray effects. Almaty mountain cosmic ray station is one of the most suitable and sensitive stations for investigation and forecasting of the dangerous situations for satellites; for this reason Almaty cosmic ray station is included in the world-wide neutron monitor network for the real-time monitoring of the space weather conditions and European Database NMDB (www.nmdb.eu). All data are represented on the web-site of the Institute of Ionosphere (www.ionos.kz) in real time. Since July, 2006 the space environment prediction laboratory represents the forecast of geomagnetic activity every day on the same site (www.ionos.kz/?q=en/node/21).

  7. Weathering and erosion fluxes of arsenic in watershed mass budgets.

    PubMed

    Drahota, Petr; Paces, Tomás; Pertold, Zdenek; Mihaljevic, Martin; Skrivan, Petr

    2006-12-15

    Arsenic in natural waters and in soils represents a serious health hazard. Natural sources of this element in soil are the subject of this communication. Weathering mass balance of As and rates of weathering in soils are evaluated from monitored inputs and outputs in two small watersheds. These watersheds are located within the Celina-Mokrsko gold district, Czech Republic. Annual chemical weathering fluxes of As are calculated from the monthly weighted means of stream water and groundwater. The fluxes are corrected for atmospheric precipitation, agrochemical inputs, and biological uptake. Mechanical and chemical weathering rates of the arsenopyrite-bearing rocks in the watersheds were estimated from mass balance data on sodium and silica. The input of As due to total weathering of bedrock was estimated to be 1369 g ha(-1)yr(-1) in the Mokrsko watershed (MW) and 81 g ha(-1)yr(-1) in the Celina watershed (CW). These results indicate that the annual weathering rate of As in the watersheds represents more than 95% of the total As input to the soil. Accumulation rate of As in the soil was estimated at 311 g ha(-1)yr(-1) in MW and 69 g ha(-1)yr(-1) in CW. The mass balance method for calculation of weathering rate of As was used, and the results suggest that weathering could be the most important process in the As biogeochemistry of the areas with elevated As content in the bedrock. Simple model of weathering and erosion can be used successfully in estimating their role in As pollution on the scale of small watershed. The method is also useful for indicating the mass balance of As in soils that is controlled by both the natural and anthropogenic inputs and outputs of As. PMID:17067656

  8. Fungal attack on rock: solubilization and altered infrared spectra.

    PubMed

    Silverman, M P; Munoz, E F

    1970-09-01

    Penicillium simplicissimum, isolated from weathering basalt, produced citric acid when grown in a glucose-mineral salts medium with basalt, granite, granodiorite, rhyolite, andesite, peridotite, dunite, or quartzite. After 7 days' growth as much as 31 percent of the silicon, 11 percent of the aluminum, 64 percent of the iron, and 59 percent of the magnesium in some of the rocks were solubilized, and a number of rocks showed altered infrared absorption in the silicon-oxygen vibration region. PMID:17838175

  9. Beneath it all: bedrock geology of the Catskill Mountains and implications of its weathering.

    PubMed

    Ver Straeten, Charles A

    2013-09-01

    The Devonian-age bedrock of the Catskill Mountains has been the focus of many studies. This paper reviews the character and composition of the rocks of the Catskills, and examines weathering (rock decay) processes and their implications in the Catskills. Rocks of the Catskills and closest foothills consist of siliciclastic rocks (sandstones, mudrocks, conglomerates) with minimal, locally dispersed carbonate rocks. The former are dominated by quartz, metamorphic and sedimentary rock fragments, and clay minerals. Other minor sediment components include cements, authigenic and heavy minerals, and fossil organic matter. Physical, chemical, and biological weathering of the Catskill bedrock since uplift of the Appalachian region, combined with glaciation, have dissected a plateau of nearly horizontally layered rocks into a series of ridges, valleys, and peaks. The varied weathering processes, in conjunction with many factors (natural and anthropogenic), fragment the rocks, forming sediment and releasing various elements and compounds. These may have positive, neutral, or negative implications for the region's soils, waters, ecology, and human usage. A new generation of studies and analyses of the Catskill bedrock is needed to help answer a broad set of questions and problems across various fields of interest. PMID:23895551

  10. Cenozoic carbon cycle imbalances and a variable weathering feedback

    NASA Astrophysics Data System (ADS)

    Caves, Jeremy K.; Jost, Adam B.; Lau, Kimberly V.; Maher, Kate

    2016-09-01

    The long-term stability of Earth's climate and the recovery of the ocean-atmosphere system after carbon cycle perturbations are often attributed to a stabilizing negative feedback between silicate weathering and climate. However, evidence for the operation of this feedback over million-year timescales and in response to tectonic and long-term climatic change remains scarce. For example, the past 50 million years of the Cenozoic Era are characterized by long-term cooling and declining atmospheric CO2 (pCO2). During this interval, constant or decreasing carbon fluxes from the solid Earth to the atmosphere suggest that stable or decreasing weathering fluxes are needed to balance the carbon cycle. In contrast, marine isotopic proxies of weathering (i.e., 87Sr/86Sr, δ7 Li , and 187Os/188Os) are interpreted to reflect increasing weathering fluxes. Here, we evaluate the existence of a negative feedback by reconstructing the imbalance in the carbon cycle during the Cenozoic using the surface inventories of carbon and alkalinity. Only a sustained 0.25-0.5% increase in silicate weathering is necessary to explain the long-term decline in pCO2 over the Cenozoic. We propose that the long-term decrease in pCO2 is due to an increase in the strength of the silicate weathering feedback (i.e., the constant of proportionality between the silicate weathering flux and climate), rather than an increase in the weathering flux. This increase in the feedback strength, which mirrors the marine isotope proxies, occurs as transient, <1 million year increases in the weathering flux, which remove CO2. As runoff and temperature decline in response, the integrated weathering flux over >1 million year timescales remains invariant to match the long-term inputs of carbon. Over the Cenozoic, this results in stable long-term weathering fluxes even as pCO2 decreases. We attribute increasing feedback strength to a change in the type and reactivity of rock in the weathering zone, which collectively has

  11. Weathering, Soil Production, and Erosion Across Climatic and Tectonic Gradients

    NASA Astrophysics Data System (ADS)

    Norton, K. P.; Larsen, I. J.

    2014-12-01

    Weathering is one of the fundamental processes that sustain life on our planet. Physical weathering breaks down rock for soil production and chemical weathering is thought to operate as the ultimate long-term negative feedback on atmospheric CO2 concentrations. There remains, however, uncertainty as to the relationship between chemical and physical weathering at very fast rates. If chemical weathering becomes kinetically limited at rapid erosion rates, as has been shown in a number of locations around the globe, then the fastest erosion rates will be associated with reduced chemical weathering. This has led to a debate as to whether tectonically active mountain ranges or rolling plains are the main source of CO2 drawdown through silicate weathering. At the heart of this debate is the dearth of chemical weathering data at fast erosion rates. New cosmogenic nuclide-derived denudation rates from the West Coast of the New Zealand Southern Alps are among the fastest in the world and are linearly correlated with chemical weathering rates. The associated soil production rates reach an order of magnitude faster than previous estimates and far exceed the suggested maximum soil production rate. This suggests that very fast weathering and soil production is possible in such active landscapes and extreme climates. We investigate the controls on these rapid rates with a climate-driven soil production model. At the most basic level, soil production requires chemical weathering of primary minerals to secondary minerals. We apply soil production models with both exponential and hump-shaped dependencies on soil thickness. Mean annual temperature and precipitation are incorporated in the form of a modified Arrhenius equation that controls the maximum soil production rate. When applied to the Southern Alps, the model predicts very rapid soil production that matches the magnitude of the cosmogenic nuclide-derived rates. High annual precipitation in the Southern Alps supports rapid

  12. Can Low Water/Rock Hydrothermal Alteration of Impact Materials Explain the Rock Component of the Martian Soil?

    NASA Technical Reports Server (NTRS)

    Nelson, M. J.; Newsom, H. E.

    2003-01-01

    The martian regolith is a globally homogenized product of chemical and aeolian weathering processes. The soil is thought to consist of a rock component, with lesser amounts of mobile elements (Ca, Na, and K) than a presumed protolith, and a salt or mobile element component enriched in sulfur and chlorine. In this study we consider the contributions of hydrothermal processes to the origin of the rock component of the martian soil.

  13. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, K.; Hong, S.; Park, S.; Kim, Y. Y.; Wi, G.

    2015-12-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  14. Space Weather Services of Korea

    NASA Astrophysics Data System (ADS)

    Yoon, KiChang; Kim, Jae-Hun; Kim, Young Yun; Kwon, Yongki; Wi, Gwan-sik

    2016-07-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  15. Weather dissemination and public usage

    NASA Technical Reports Server (NTRS)

    Stacey, M. S.

    1973-01-01

    The existing public usage of weather information was examined. A survey was conducted to substantiate the general public's needs for dissemination of current (0-12 hours) weather information, needs which, in a previous study, were found to be extensive and urgent. The goal of the study was to discover how the general public obtains weather information, what information they seek and why they seek it, to what use this information is put, and to further ascertain the public's attitudes and beliefs regarding weather reporting and the diffusion of weather information. Major findings from the study include: 1. The public has a real need for weather information in the 0-6 hour bracket. 2. The visual medium is preferred but due to the lack of frequent (0-6 hours) forecasts, the audio media only, i.e., telephone recordings and radio weathercasts, were more frequently used. 3. Weather information usage is sporadic.

  16. The chemical weathering regime of Kärkevagge, arctic-alpine Sweden

    NASA Astrophysics Data System (ADS)

    Thorn, Colin E.; Darmody, Robert G.; Dixon, John C.; Schlyter, Peter

    2001-11-01

    Kärkevagge is a valley located in Swedish Lapland at approximately 68°N and represents an arctic-alpine landscape. It is a presently periglacial, glaciated trough incised into essentially horizontal metamorphic rocks, some of which are presumably pyrite-rich. A set of coordinated studies was undertaken to investigate the nature of chemical weathering and pedogenesis in the valley and upon the abutting ridges. August 1996 water quality measures reveal considerable spatial variation in solute totals with the highest Total Dissolved Solute abundances being correlated with high sulfate abundances. Ridge-crest soils exhibited poor horizonation, but more extensive development of secondary clay minerals developed in situ than was found in valley-flank and valley-bottom soils. Valley soils exhibited multiple thin horizons, many of which were buried, and are taken to reflect great paraglacial and periglacial instability. Favorable microenvironments in the valley permit significant development of Spodosols. Coarse debris along and across the valley bears both weathering rinds and rock coatings. Rock coatings in the valley include several types of iron films, sulfate crusts, carbonate skins, and heavy metal skins. Kärkevagge represents a mild arctic environment, which does not preclude substantial chemical weathering in locations where abundant pyrite-rich bedrock and water coincide. This weathering follows pathways which are eminently expectable given that weathering of the pyrite-rich rock permits generation of sulfuric acid which, in turn, weathers muscovite mica and calcite in local schists and marble, respectively. Zones of intense chemical weathering also generate clearly visible deposits of gypsum and iron sulfate deposits such as jarosite. Not all arctic and/or alpine environments are likely to be so active chemically, but the results from Kärkevagge clearly show that dismissal of chemical weathering in cold regions on the basis of presumed first principles is

  17. Sun-weather relationships

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The possible processes in the lower atmosphere of the earth initiated or controlled by changes in the output of the sun are investigated. These changes can include solar variation in radiation (as in the constant, or in specific wavelength regions), in particles (as in physical properties of the solar wind, or in solar cosmic rays, or solar-modulated galactic cosmic rays), and in the extended magnetic field of the sun (as in circumstances of the passage of interplanetary sector boundaries). Changes of short term (in the weather) as well as long term (in regional or global climate) are considered.

  18. Terminal Doppler weather radar

    NASA Astrophysics Data System (ADS)

    Michelson, M.; Shrader, W. W.; Wieler, J. G.

    1990-02-01

    The terminal Doppler weather radar (TDWR) system, now under development, will provide automatic detection of microbursts and low-level wind shear. This paper discusses the TDWR performance parameters and describes its structural elements, including the antenna subsystem, the transmitter, the receiver/exciter, the digital signal processor, and the radar product generator/remote monitoring subsystem. Attention is also given to the processes of the base data formation, point target removal, signal-to-noise thresholding, and velocity de-aliasing and to the TDWR algorithms and displays. A schematic diagram of the TDWR system is presented.

  19. Utilities weather the storm

    SciTech Connect

    Lihach, N.

    1984-11-01

    Utilities must restore power to storm-damaged transmission and distribution systems, even if it means going out in ice storms or during lightning and hurricane conditions. Weather forecasting helps utilities plan for possible damage as well as alerting them to long-term trends. Storm planning includes having trained repair personnel available and adjusting the system so that less power imports are needed. Storm damage response requires teamwork and cooperation between utilities. Utilities can strengthen equipment in storm-prone or vulnerable areas, but good data are necessary to document the incidence of lighning strikes, hurricanes, etc. 2 references, 8 figures.

  20. Weather Balloon Ascent Rate

    NASA Astrophysics Data System (ADS)

    Denny, Mark

    2016-05-01

    The physics of a weather balloon is analyzed. The surprising aspect of the motion of these balloons is that they ascend to great altitudes (typically 35 km) at a more or less constant rate. Such behavior is not surprising near the ground—say for a helium-filled party balloon rising from street level to the top of the Empire State building—but it is unexpected for a balloon that rises to altitudes where the air is rarefied. We show from elementary physical laws why the ascent rate is approximately constant.

  1. Polarimetric Doppler Weather Radar

    NASA Astrophysics Data System (ADS)

    Bringi, V. N.; Chandrasekar, V.

    2001-10-01

    This work provides a detailed introduction to the principles of Doppler and polarimetric radar, focusing in particular on their use in the analysis of weather systems. The authors first discuss underlying topics such as electromagnetic scattering, polarization, and wave propagation. They then detail the engineering aspects of pulsed Doppler polarimetric radar, before examining key applications in meteorology and remote sensing. The book is aimed at graduate students of electrical engineering and atmospheric science as well as practitioners involved in the applications of polarimetric radar.

  2. Weather Forecasting Aid

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Weather forecasters are usually very precise in reporting such conditions as temperature, wind velocity and humidity. They also provide exact information on barometric pressure at a given moment, and whether the barometer is "rising" or "falling"- but not how rapidly or how slowly it is rising or falling. Until now, there has not been available an instrument which measures precisely the current rate of change of barometric pressure. A meteorological instrument called a barograph traces the historical ups and downs of barometric pressure and plots a rising or falling curve, but, updated every three hours, it is only momentarily accurate at each updating.

  3. Severe Weather Forecast Decision Aid

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  4. Fossil Microorganisms and Formation of Early Precambrian Weathering Profiles

    NASA Technical Reports Server (NTRS)

    Rozanov, A. Yu; Astafieva, M. M.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

    2009-01-01

    Weathering crusts are the only reliable evidences of the existence of continental conditions. Often they are the only source of information about exogenous processes and subsequently about conditions under which the development of the biosphere occurred. A complex of diverse fossil microorganisms was discovered as a result of Scanning Electron Microscope investigations. The chemical composition of the discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, the microorganisms fixed in rocks played the role of catalyst. The decomposition of minerals comprising the rocks and their transformation into clayey (argillaceous) minerals, most likely occurred under the influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

  5. Enhanced weathering strategies for stabilizing climate and averting ocean acidification

    NASA Astrophysics Data System (ADS)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2016-04-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m-2 yr-1) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  6. Enhanced Weathering Strategies for Stabilizing Climate and Averting Ocean Acidification

    NASA Technical Reports Server (NTRS)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2015-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m(exp -2) yr (exp -1)) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  7. Quantifying the Chemical Weathering Efficiency of Basaltic Catchments

    NASA Astrophysics Data System (ADS)

    Ibarra, D. E.; Caves, J. K.; Thomas, D.; Chamberlain, C. P.; Maher, K.

    2014-12-01

    The geographic distribution and areal extent of rock type, along with the hydrologic cycle, influence the efficiency of global silicate weathering. Here we define weathering efficiency as the production of HCO3- for a given land surface area. Modern basaltic catchments located on volcanic arcs and continental flood basalts are particularly efficient, as they account for <5% of sub-aerial bedrock but produce ~30% of the modern global weathering flux. Indeed, changes in this weathering efficiency are thought to play an important role in modulating Earth's past climate via changes in the areal extent and paleo-latitude of basaltic catchments (e.g., Deccan and Ethiopian Traps, southeast Asia basaltic terranes). We analyze paired river discharge and solute concentration data for basaltic catchments from both literature studies and the USGS NWIS database to mechanistically understand geographic and climatic influences on weathering efficiency. To quantify the chemical weathering efficiency of modern basalt catchments we use solute production equations and compare the results to global river datasets. The weathering efficiency, quantified via the Damköhler coefficient (Dw [m/yr]), is calculated from fitting concentration-discharge relationships for catchments with paired solute and discharge measurements. Most basalt catchments do not demonstrate 'chemostatic' behavior. The distribution of basalt catchment Dw values (0.194 ± 0.176 (1σ)), derived using SiO2(aq) concentrations, is significantly higher than global river Dw values (mean Dw of 0.036), indicating a greater chemical weathering efficiency. Despite high Dw values and total weathering fluxes per unit area, many basaltic catchments are producing near their predicted weathering flux limit. Thus, weathering fluxes from basaltic catchments are proportionally less responsive to increases in runoff than other lithologies. The results of other solute species (Mg2+ and Ca2+) are comparable, but are influenced both by

  8. Martian weathering processes: Terrestrial analog and theoretical modeling studies

    NASA Astrophysics Data System (ADS)

    McAdam, Amy Catherine

    2008-06-01

    Understanding the role of water in the Martian near-surface, and its implications for possible habitable environments, is among the highest priorities of NASA's Mars Exploration Program. Characterization of alteration signatures in surface materials provides the best opportunity to assess the role of water on Mars. This dissertation investigates Martian alteration processes through analyses of Antarctic analogs and numerical modeling of mineral-fluid interactions. Analog work involved studying an Antarctic diabase, and associated soils, as Mars analogs to understand weathering processes in cold, dry environments. The soils are dominated by primary basaltic minerals, but also contain phyllosilicates, salts, iron oxides/oxyhydroxides, and zeolites. Soil clay minerals and zeolites, formed primarily during deuteric or hydrothermal alteration of the parent rock, were subsequently transferred to the soil by physical rock weathering. Authigenic soil iron oxides/oxyhydroxides and small amounts of poorly-ordered secondary silicates indicate some contributions from low-temperature aqueous weathering. Soil sulfates, which exhibit a sulfate- aerosol-derived mass-independent oxygen isotope signature, suggest contributions from acid aerosol-rock interactions. The complex alteration history of the Antarctic materials resulted in several similarities to Martian materials. The processes that affected the analogs, including deuteric/ hydrothermal clay formation, may be important in producing Martian surface materials. Theoretical modeling focused on investigating the alteration of Martian rocks under acidic conditions and using modeling results to interpret Martian observations. Kinetic modeling of the dissolution of plagioclase-pyroxene mineral mixtures under acidic conditions suggested that surfaces with high plagioclase/pyroxene, such as several northern regions, could have experienced some preferential dissolution of pyroxenes at a pH less than approximately 3-4. Modeling of the

  9. NASA Space Weather Center Services: Potential for Space Weather Research

    NASA Technical Reports Server (NTRS)

    Zheng, Yihua; Kuznetsova, Masha; Pulkkinen, Antti; Taktakishvili, A.; Mays, M. L.; Chulaki, A.; Lee, H.; Hesse, M.

    2012-01-01

    The NASA Space Weather Center's primary objective is to provide the latest space weather information and forecasting for NASA's robotic missions and its partners and to bring space weather knowledge to the public. At the same time, the tools and services it possesses can be invaluable for research purposes. Here we show how our archive and real-time modeling of space weather events can aid research in a variety of ways, with different classification criteria. We will list and discuss major CME events, major geomagnetic storms, and major SEP events that occurred during the years 2010 - 2012. Highlights of major tools/resources will be provided.

  10. Vodcasting Space Weather

    NASA Astrophysics Data System (ADS)

    Collins Petersen, Carolyn; Erickson, P. J.; Needles, M.

    2009-01-01

    The topic of space weather is the subject of a series of vodcasts (video podcasts) produced by MIT Haystack Observatory (Westford, MA) and Loch Ness Productions (Groton, MA). This paper discusses the production and distribution of the series via Webcast, Youtube, and other avenues. It also presents preliminary evaluation of the effectiveness and outreach of the project through feedback from both formal and information education venues. The vodcast series is linked to the NASA Living With a Star Targeted Research and Technology project award "Multi-Instrument Investigation of Inner-Magnetospheric/Ionosphere Disturbances.” It is being carried out by Principal Investigator Dr. John Foster, under the auspices of NASA Grant # NNX06AB86G. The research involves using ionospheric total electron content (TEC) observations to study the location, extent, and duration of perturbations within stormtime ionospheric electric fields at mid- to low latitudes. It combines ground-based global positioning system (GPS) TEC data, incoherent scatter radar measurements of the mid-latitude ionospheric state, and DMSP satellite observations to characterize conditions which lead to severe low-latitude ionospheric perturbations. Each vodcast episode covers a certain aspect of space weather and the research program.

  11. Weatherization Apprenticeship Program

    SciTech Connect

    Watson, Eric J

    2012-12-18

    Weatherization improvement services will be provided to Native people by Native people. The proposed project will recruit, train and hire two full-time weatherization technicians who will improve the energy efficiency of homes of Alaska Natives/American Indians residing in the Indian areas, within the Cook Inlet Region of Alaska. The Region includes Anchorage as well as 8 small tribal villages: The Native Villages of Eklutna, Knik, Chickaloon, Seldovia, Ninilchik, Kenaitze, Salamatof, and Tyonek. This project will be a partnership between three entities, with Cook Inlet Tribal Council (CITC) as the lead agency: CITCA's Employment and Training Services Department, Cook Inlet Housing Authority and Alaska Works Partnership. Additionally, six of the eight tribal villages within the Cook Inlet Region of Alaska have agreed to work with the project in order to improve the energy efficiency of their tribally owned buildings and homes. The remaining three villages will be invited to participate in the establishment of an intertribal consortium through this project. Tribal homes and buildings within Anchorage fall under Cook Inlet Region, Inc. (CIRI) tribal authority.

  12. Road Weather and Connected Vehicles

    NASA Astrophysics Data System (ADS)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  13. Theory of wing rock

    NASA Technical Reports Server (NTRS)

    Hsu, C.-H.; Lan, C. E.

    1985-01-01

    Wing rock is one type of lateral-directional instabilities at high angles of attack. To predict wing rock characteristics and to design airplanes to avoid wing rock, parameters affecting wing rock characteristics must be known. A new nonlinear aerodynamic model is developed to investigate the main aerodynamic nonlinearities causing wing rock. In the present theory, the Beecham-Titchener asymptotic method is used to derive expressions for the limit-cycle amplitude and frequency of wing rock from nonlinear flight dynamics equations. The resulting expressions are capable of explaining the existence of wing rock for all types of aircraft. Wing rock is developed by negative or weakly positive roll damping, and sustained by nonlinear aerodynamic roll damping. Good agreement between theoretical and experimental results is obtained.

  14. Rocks in Our Pockets

    ERIC Educational Resources Information Center

    Plummer, Donna; Kuhlman, Wilma

    2005-01-01

    To introduce students to rocks and their characteristics, teacher can begin rock units with the activities described in this article. Students need the ability to make simple observations using their senses and simple tools.

  15. The Rock Cycle

    ERIC Educational Resources Information Center

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  16. Rocks and Minerals.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

    Provides background information on rocks and minerals, including the unique characteristics of each. Teaching activities on rock-hunting and identification, mineral configurations, mystery minerals, and growing crystals are provided. Reproducible worksheets are included for two of the activities. (TW)

  17. Weather Forecasting Systems and Methods

    NASA Technical Reports Server (NTRS)

    Mecikalski, John (Inventor); MacKenzie, Wayne M., Jr. (Inventor); Walker, John Robert (Inventor)

    2014-01-01

    A weather forecasting system has weather forecasting logic that receives raw image data from a satellite. The raw image data has values indicative of light and radiance data from the Earth as measured by the satellite, and the weather forecasting logic processes such data to identify cumulus clouds within the satellite images. For each identified cumulus cloud, the weather forecasting logic applies interest field tests to determine a score indicating the likelihood of the cumulus cloud forming precipitation and/or lightning in the future within a certain time period. Based on such scores, the weather forecasting logic predicts in which geographic regions the identified cumulus clouds will produce precipitation and/or lighting within during the time period. Such predictions may then be used to provide a weather map thereby providing users with a graphical illustration of the areas predicted to be affected by precipitation within the time period.

  18. Weather forecasting expert system study

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Weather forecasting is critical to both the Space Transportation System (STS) ground operations and the launch/landing activities at NASA Kennedy Space Center (KSC). The current launch frequency places significant demands on the USAF weather forecasters at the Cape Canaveral Forecasting Facility (CCFF), who currently provide the weather forecasting for all STS operations. As launch frequency increases, KSC's weather forecasting problems will be great magnified. The single most important problem is the shortage of highly skilled forecasting personnel. The development of forecasting expertise is difficult and requires several years of experience. Frequent personnel changes within the forecasting staff jeopardize the accumulation and retention of experience-based weather forecasting expertise. The primary purpose of this project was to assess the feasibility of using Artificial Intelligence (AI) techniques to ameliorate this shortage of experts by capturing aria incorporating the forecasting knowledge of current expert forecasters into a Weather Forecasting Expert System (WFES) which would then be made available to less experienced duty forecasters.

  19. Biotic enhancement of weathering, atmospheric oxygen and carbon dioxide in the Neoproterozoic

    NASA Astrophysics Data System (ADS)

    Lenton, Timothy M.; Watson, Andrew J.

    2004-03-01

    It has been suggested that biological colonization of the land surface began in the Neoproterozoic 1000-544 million years ago (Ma). We hypothesize that this colonization involved selective weathering of P from rocks, as well as an amplification of overall weathering rates. We show that two recent models, despite differences in the feedback mechanisms represented, predict that an increase in the weathering flux of P to the ocean would have caused a rise in atmospheric O2 in the Neoproterozoic. This in turn may have provided a necessary condition for the evolution of animals with hard skeletons seen in the 'Cambrian explosion'. Increased weathering of silicate rocks would also have caused a decline in atmospheric CO2, which could have been a causal factor in the Neoproterozoic glaciations.

  20. Biogenic Cracks in Porous Rock

    NASA Astrophysics Data System (ADS)

    Hemmerle, A.; Hartung, J.; Hallatschek, O.; Goehring, L.; Herminghaus, S.

    2014-12-01

    Microorganisms growing on and inside porous rock may fracture it by various processes. Some of the mechanisms of biofouling and bioweathering are today identified and partially understood but most emphasis is on chemical weathering, while mechanical contributions have been neglected. However, as demonstrated by the perseverance of a seed germinating and cracking up a concrete block, the turgor pressure of living organisms can be very significant. Here, we present results of a systematic study of the effects of the mechanical forces of growing microbial populations on the weathering of porous media. We designed a model porous medium made of glass beads held together by polydimethylsiloxane (PDMS), a curable polymer. The rheological properties of the porous medium, whose shape and size are tunable, can be controlled by the ratio of crosslinker to base used in the PDMS (see Fig. 1). Glass and PDMS being inert to most chemicals, we are able to focus on the mechanical processes of biodeterioration, excluding any chemical weathering. Inspired by recent measurements of the high pressure (~0.5 Mpa) exerted by a growing population of yeasts trapped in a microfluidic device, we show that yeast cells can be cultured homogeneously within porous medium until saturation of the porous space. We investigate then the effects of such an inner pressure on the mechanical properties of the sample. Using the same model system, we study also the complex interplay between biofilms and porous media. We focus in particular on the effects of pore size on the penetration of the biofilm within the porous sample, and on the resulting deformations of the matrix, opening new perspectives into the understanding of life in complex geometry. Figure 1. Left : cell culture growing in a model porous medium. The white spheres represent the grains, bonds are displayed in grey, and microbes in green. Right: microscopy picture of glass beads linked by PDMS bridges, scale bar: 100 μm.

  1. Principles of rock deformation

    SciTech Connect

    Nicolas, A.

    1987-01-01

    This text focuses on the recent achievements in the analysis of rock deformation. It gives an analytical presentation of the essential structures in terms of kinetic and dynamic interpretation. The physical properties underlying the interpretation of rock structures are exposed in simple terms. Emphasized in the book are: the role of fluids in rock fracturing; the kinematic analysis of magnetic flow structures; the application of crystalline plasticity to the kinematic and dynamic analysis of the large deformation imprinted in many metamorphic rocks.

  2. An aem-tem study of weathering and diagenesis, Abert Lake, Oregon: I. Weathering reactions in the volcanics

    USGS Publications Warehouse

    Banfield, J.F.; Jones, B.F.; Veblen, D.R.

    1991-01-01

    Abert Lake in south-central Oregon provides a site suitable for the study of sequential weathering and diagenetic events. In this first of two papers, transmission electron microscopy was used to characterize the igneous mineralogy, subsolidus alteration assemblage, and the structural and chemical aspects of silicate weathering reactions that occur in the volcanic rocks (basalts, basaltic andesites, and dacitic/ rhyolitic extrusive and pyroclastics) that outcrop around the lake. Olivine and pyroxene replacement occurred topotactically, whereas feldspar and glass alteration produced randomly oriented smectite in channels and cavities. The tetrahedral, octahedral, and interlayer compositions of the weathering products, largely dioctahedral smectites, varied with primary mineral composition, rock type, and as the result of addition of elements released from adjacent reaction sites. Weathering of the highly evolved, Fe-rich Jug Mountain complex at the north end of the lake produced a homogeneous smectite assemblage that contrasts with the heterogeneous smectite assemblage replacing the volcanics along the eastern margin of the lake. The variability within and between the smectite assemblages highlights the microenvironmental diversity, fluctuating redox conditions, and variable solution chemistry associated with mineral weathering reactions in the surficial environment. Late-stage exhalative and aqueous alteration of the volcanics redistributed many components and formed a variety of alkali and alkali-earth carbonate, chloride, sulfate, and fluoride minerals in vugs and cracks. Overall, substantial Mg, Si, Na, Ca, and K are released by weathering reactions that include the almost complete destruction of the Mg-smectite that initially replaced olivine. The leaching of these elements from the volcanics provides an important source of these constituents in the lake water. The nature of subsequent diagenetic reactions resulting from the interaction between the materials

  3. My Pet Rock

    ERIC Educational Resources Information Center

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  4. Bishop Paiute Weatherization Training Program

    SciTech Connect

    Carlos Hernandez

    2010-01-28

    The DOE Weatherization Training Grant assisted Native American trainees in developing weatherization competencies, creating employment opportunities for Bishop Paiute tribal members in a growing field. The trainees completed all the necessary training and certification requirements and delivered high-quality weatherization services on the Bishop Paiute Reservation. Six tribal members received all three certifications for weatherization; four of the trainees are currently employed. The public benefit includes (1) development of marketable skills by low-income Native individuals, (2) employment for low-income Native individuals in a growing industry, and (3) economic development opportunities that were previously not available to these individuals or the Tribe.

  5. Solar weather/climate predictions

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.; Goldberg, R. A.; Mitchell, J. M.; Olson, R.; Schaefer, J.; Silverman, S.; Wilcox, J.; Williams, G.

    1979-01-01

    Solar variability influences upon terrestrial weather and climate are addressed. Both the positive and negative findings are included and specific predictions, areas of further study, and recommendations listed.

  6. Space Weathering: An Ultraviolet Indicator

    NASA Technical Reports Server (NTRS)

    Hendrix, A. R.; Vilas, F.

    2003-01-01

    We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to detect the longer-wavelength weathering effects.

  7. Space Weathering: An Ultraviolet Indicator

    NASA Technical Reports Server (NTRS)

    Hendrix, A. R.; Vilas, F.

    2004-01-01

    We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to detect the longer-wavelength weathering effects.

  8. AWE: Aviation Weather Data Visualization

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly; Lodha, Suresh K.

    2001-01-01

    The two official sources for aviation weather reports both require the pilot to mentally visualize the provided information. In contrast, our system, Aviation Weather Environment (AWE) presents aviation specific weather available to pilots in an easy to visualize form. We start with a computer-generated textual briefing for a specific area. We map this briefing onto a grid specific to the pilot's route that includes only information relevant to his flight route that includes only information relevant to his flight as defined by route, altitude, true airspeed, and proposed departure time. By modifying various parameters, the pilot can use AWE as a planning tool as well as a weather briefing tool.

  9. Small Sensors for Space Weather

    NASA Astrophysics Data System (ADS)

    Nicholas, A. C.

    2015-12-01

    The Naval Research Laboratory is actively pursuing enhancing the nation's space weather sensing capability. One aspect of this plan is the concept of flying Space Weather sensor suites on host spacecraft as secondary payloads. The emergence and advancement of the CubeSat spacecraft architecture has produced a viable platform for scientifically and operationally relevant Space Weather sensing. This talk will provide an overview of NRL's low size weight and power sensor technologies targeting Space Weather measurements. A summary of on-orbit results of past and current missions will be presented, as well as an overview of future flights that are manifested and potential constellation missions.

  10. 68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. LITTLE ROCK AND PALMDALE IRRIGATION DISTRICT, LITTLE ROCK DAM: STRESS SHEET, SHEET 4; MAY, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  11. Complex Molybdenum Isotope Behavior During Weathering and Erosional Transport

    NASA Astrophysics Data System (ADS)

    Siebert, C.; Pett-Ridge, J. C.; Burton, K.; Halliday, A. N.

    2009-12-01

    The oceans play a major role in regulating global climate because they both react and drive changes in other geochemical reservoirs. Non-traditional stable isotope systems have become important proxies for changes in ocean chemistry making the quantification of these changes possible. Molybdenum isotopes have great potential as tracers of changes in the oxygenation of the oceans over geological time scales. Although significant progress has been made and the amount of data on the biogeochemical behaviour of Mo in the marine environment has been increasing rapidly over the last few years, some important aspects of Mo geochemistry remain poorly understood. These include diagenetic processes at continental margins and continental weathering. Mo isotope behaviour in these settings has a potentially large impact on the interpretation of the geological record. A recent study of Archer and Vance (2008) has shown that dissolved Mo in many of Earths major rivers has a heavy isotope composition relative to most magmatic rocks. A potential cause for this isotope composition in modern rivers is isotope fractionation during weathering and erosion processes. We investigated Mo isotope behaviour in weathering profiles from Hawaii and Puerto Rico. Results clearly show significant Mo isotope fractionation during chemical weathering. Mo retained in saprolithe samples from Hawaii has light isotope compositions of up to -0.5 permill. The extent of fractionation is dependent on redox-conditions in the investigated profiles. The particular setting of these profiles keeps other factors that might influence the Mo isotope composition to a minimum. The results also indicate the possible use of Mo isotope signals as paleoredox-proxy of weathering processes. However, a weathering profile with intermittent changes in redox, pH and porewater saturation show more variable Mo isotope signals with partly positive isotope values. Sequential extractions of saphrolite samples show a clear

  12. Martian weathering products as tracers of climate change and atmosphere/hydrosphere evolution on Mars

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1988-01-01

    Primary objectives for exploration of Mars include determination of: (1) the distribution, abundance, and sources and sinks of volatile materials, and (2) the interaction of surface materials with the atmosphere. Both objectives fall within the purview of planetary surface weathering studies and require documented samples of weathered materials, including rock surfaces, soils, and sediments. Major issues to be addressed in selecting and studying Martian samples in this context are summarized.

  13. Nitrogen in rock: Occurrences and biogeochemical implications

    USGS Publications Warehouse

    Holloway, J.M.; Dahlgren, R.A.

    2002-01-01

    There is a growing interest in the role of bedrock in global nitrogen cycling and potential for increased ecosystem sensitivity to human impacts in terrains with elevated background nitrogen concentrations. Nitrogen-bearing rocks are globally distributed and comprise a potentially large pool of nitrogen in nutrient cycling that is frequently neglected because of a lack of routine analytical methods for quantification. Nitrogen in rock originates as organically bound nitrogen associated with sediment, or in thermal waters representing a mixture of sedimentary, mantle, and meteoric sources of nitrogen. Rock nitrogen concentrations range from trace levels (>200 mg N kg -1) in granites to ecologically significant concentrations exceeding 1000 mg N kg -1 in some sedimentary and metasedimentary rocks. Nitrate deposits accumulated in arid and semi-arid regions are also a large potential pool. Nitrogen in rock has a potentially significant impact on localized nitrogen cycles. Elevated nitrogen concentrations in water and soil have been attributed to weathering of bedrock nitrogen. In some environments, nitrogen released from bedrock may contribute to nitrogen saturation of terrestrial ecosystems (more nitrogen available than required by biota). Nitrogen saturation results in leaching of nitrate to surface and groundwaters, and, where soils are formed from ammonium-rich bedrock, the oxidation of ammonium to nitrate may result in soil acidification, inhibiting revegetation in certain ecosystems. Collectively, studies presented in this article reveal that geologic nitrogen may be a large and reactive pool with potential for amplification of human impacts on nitrogen cycling in terrestrial and aquatic ecosystems.

  14. The formation of technic soil in a revegetated uranium ore waste rock pile (Limousin, France)

    NASA Astrophysics Data System (ADS)

    Boekhout, Flora; Gérard, Martine; Kanzari, Aisha; Calas, Georges; Descostes, Michael

    2014-05-01

    Mining took place in France between 1945 and 2001 during which time ~210 different sites were exploited and/or explored. A total of 76 Kt of uranium was produced, 52 Mt of ore was extracted, but also 200 Mt of waste rocks was produced, the majority of which, with uranium levels corresponding to the natural environment. So far, the processes of arenisation and technic soil formation in waste rock piles are not well understood but have important implications for understanding the environmental impact and long-term speciation of uranium. Understanding weathering processes in waste rock piles is essential to determine their environmental impact. The main objectives of this work are to assess 1) the micromorphological features and neo-formed U-bearing phases related to weathering and 2) the processes behind arenisation of the rock pile. The site that was chosen is the Vieilles Sagnes waste rock pile in Fanay (Massif Central France) that represents more or less hydrothermally altered granitic rocks that have been exposed to weathering since the construction of the waste rock pile approximately 50 years ago. Two trenches were excavated to investigate the vertical differentiation of the rock pile. This site serves as a key location for studying weathering processes of waste rock piles, as it has not been reworked after initial construction and has therefore preserved information on the original mineralogy of the waste rock pile enabling us to access post emplacement weathering processes. The site is currently overgrown by moss, meter high ferns and small trees. At present day the rock pile material can be described as hydrothermally altered rocks and rock fragments within a fine-grained silty clay matrix exposed to surface conditions and weathering. A sandy "paleo" technic soil underlies the waste rock pile and functions as a natural liner by adsorption of uranium on clay minerals. Post-mining weathering of rock-pile material is superimposed on pre-mining hydrothermal and

  15. Supporting Weather Data

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Since its founding in 1992, Global Science & Technology, Inc. (GST), of Greenbelt, Maryland, has been developing technologies and providing services in support of NASA scientific research. GST specialties include scientific analysis, science data and information systems, data visualization, communications, networking and Web technologies, computer science, and software system engineering. As a longtime contractor to Goddard Space Flight Center s Earth Science Directorate, GST scientific, engineering, and information technology staff have extensive qualifications with the synthesis of satellite, in situ, and Earth science data for weather- and climate-related projects. GST s experience in this arena is end-to-end, from building satellite ground receiving systems and science data systems, to product generation and research and analysis.

  16. Intelligent Weather Agent

    NASA Technical Reports Server (NTRS)

    Spirkovska, Liljana (Inventor)

    2006-01-01

    Method and system for automatically displaying, visually and/or audibly and/or by an audible alarm signal, relevant weather data for an identified aircraft pilot, when each of a selected subset of measured or estimated aviation situation parameters, corresponding to a given aviation situation, has a value lying in a selected range. Each range for a particular pilot may be a default range, may be entered by the pilot and/or may be automatically determined from experience and may be subsequently edited by the pilot to change a range and to add or delete parameters describing a situation for which a display should be provided. The pilot can also verbally activate an audible display or visual display of selected information by verbal entry of a first command or a second command, respectively, that specifies the information required.

  17. Micro Weather Station

    NASA Technical Reports Server (NTRS)

    Hoenk, Michael E.

    1999-01-01

    Improved in situ meteorological measurements in the troposphere and stratosphere are needed for studies of weather and climate, both as a primary data source and as validation for remote sensing instruments. Following the initial development and successful flight validation of the surface acoustic wave (SAW) hygrometer, the micro weather station program was directed toward the development of an integrated instrument, capable of accurate, in situ profiling of the troposphere, and small enough to fly on a radiosonde balloon for direct comparison with standard radiosondes. On April 23, 1998, working with Frank Schmidlin and Bob Olson of Wallops Island Flight Facility, we flew our instrument in a dual payload experiment, for validation and direct comparison with a Vaisala radiosonde. During that flight, the SAW dewpoint hygrometer measured frostpoint down to -76T at 44,000 feet. Using a laptop computer in radio contact with the balloon, we monitored data in real time, issued the cutdown command, and recovered the payload less than an hour after landing in White Sands Missile Range, 50 miles from the launch site in Hatch, New Mexico. Future flights will extend the intercomparison, and attempt to obtain in situ meteorological profiles from the surface through the tropopause. The SAW hygrometer was successfully deployed on the NASA DC8 as part of NASA's Third Convection and Moisture Experiment (CAMEX-3) during August and September, 1998. This field campaign was devoted to the study of hurricane tracking and intensification using NASA-funded aircraft. In situ humidity data from the SAW hygrometer are currently being analyzed and compared with data from other instruments on the DC8 and ER2 aircraft. Additional information is contained in the original.

  18. Terminal weather information management

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.

    1990-01-01

    Since the mid-1960's, microburst/windshear events have caused at least 30 aircraft accidents and incidents and have killed more than 600 people in the United States alone. This study evaluated alternative means of alerting an airline crew to the presence of microburst/windshear events in the terminal area. Of particular interest was the relative effectiveness of conventional and data link ground-to-air transmissions of ground-based radar and low-level windshear sensing information on microburst/windshear avoidance. The Advanced Concepts Flight Simulator located at Ames Research Center was employed in a line oriented simulation of a scheduled round-trip airline flight from Salt Lake City to Denver Stapleton Airport. Actual weather en route and in the terminal area was simulated using recorded data. The microburst/windshear incident of July 11, 1988 was re-created for the Denver area operations. Six experienced airline crews currently flying scheduled routes were employed as test subjects for each of three groups: (1) A baseline group which received alerts via conventional air traffic control (ATC) tower transmissions; (2) An experimental group which received alerts/events displayed visually and aurally in the cockpit six miles (approx. 2 min.) from the microburst event; and (3) An additional experimental group received displayed alerts/events 23 linear miles (approx. 7 min.) from the microburst event. Analyses of crew communications and decision times showed a marked improvement in both situation awareness and decision-making with visually displayed ground-based radar information. Substantial reductions in the variability of decision times among crews in the visual display groups were also found. These findings suggest that crew performance will be enhanced and individual differences among crews due to differences in training and prior experience are significantly reduced by providing real-time, graphic display of terminal weather hazards.

  19. Basalt Weathering Rates Across Scales

    NASA Astrophysics Data System (ADS)

    Navarresitchler, A.; Brantley, S.

    2006-12-01

    Weathering of silicate minerals is a known sink for atmospheric CO2. An estimated 30%-35% of the consumption of CO2 from continental silicate weathering can be attributed to basalt weathering (Dessert et al., 2003). To assess basalt weathering rates we examine weathering advance rates of basalt (w, mm/yr) reported at four scales: denudation rates from basalt watersheds (tens of kilometers), rates of soil formation from soil profiles developed on basaltic parent material of known age (meters), rates of weathering rind formation on basalt clasts (centimeters), and laboratory dissolution rates (millimeters). Basalt weathering advance rates calculated for watersheds range between 0.36 and 9.8x10-3 mm/yr. The weathering advance rate for a basalt soil profile in Hawaii is 8.0x10-3 mm/yr while advance rates for clasts range from 5.6x10-6 to 2.4x10-4 mm/yr. Batch and mixed flow laboratory experiments performed at circum- neutral pH yield advance rates of 2.5x10^{-5} to 3.4x10-7 mm/yr when normalized to BET surface area. These results show increasing advance rates with both increasing scale (from laboratory to watersheds) and increasing temperature. If we assume that basalt weathers at an intrinsic rate that applies to all scales then we conclude that variations in weathering advance rates arise from variations in surface area measurement at different scales (D); therefore, basalt weathering is a fractal system. We measure a fractal dimension (dr) of basalt weathering of 2.2. For Euclidean geometries, measured surface area does not vary with the scale at which it is measured and dr equals 2. For natural surfaces, surface area is related to the scale at which it is measured. As scale increases, the minimum size of the surface irregularities that are measurable also increases. The ratio between BET and geometric normalized laboratory dissolution rates has been defined as a roughness parameter, λ, which ranges from ~10-100. We extend the definition of this roughness parameter

  20. Microcracks in lunar rocks

    NASA Technical Reports Server (NTRS)

    Simmons, G.

    1979-01-01

    Lunar samples contain abundant open microcracks that have closure characteristics completely unlike any shocked terrestrial rock; however, the microcracks present in the lunar rocks before the rocks reached the surface of the moon were likely similar to the microcracks in the shocked terrestrial rocks. Because the microcracks present in the lunar rocks in situ inside the moon were different, radically different, from the microcracks present today in returned lunar samples, any property that is sensitive to microcracks measured on the returned lunar samples is inappropriate for predicting that property as a function of depth in the moon. Therefore, many data that have been measured already on lunar samples simply do not apply to rocks in situ inside the moon. A plausible mechanism with which to account for the difference in microcrack characteristics of lunar samples on the surface of the moon and the microcrack characteristics of lunar rock in situ inside the moon is thermal cycling during residence on the moon's surface.

  1. Rates of oxidative weathering on the surface of Mars

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.

    1992-01-01

    Implicit in the mnemonic 'MSATT' (Mars surface and atmosphere through time) is that rates of surface processes on Mars through time should be investigated, including studies of the kinetics and mechanism of oxidative weathering reactions occurring in the Martian regolith. Such measurements are described. Two major elements analyzed in the Viking Lander XRF experiment that are most vulnerable to atmospheric oxidation are iron and sulfur. Originally, they occurred as Fe(2+)-bearing silicate and sulfide minerals in basaltic rocks on the surface of Mars. However, chemical weathering reactions through time have produced ferric- and sulfate-bearing assemblages now visible in the Martian regolith. Such observations raise several question about: (1) when the oxidative weathering reactions took place on Mars; (2) whether or not the oxidized regolith is a fossilized remnant of past weathering processes; (3) deducting chemical interactions of the ancient Martian atmosphere with its surface from surviving phases; (4) possible weathering reactions still occurring in the frozen regolith; and (5) the kinetics and mechanism of past and present-day oxidative reactions on Mars. These questions may be addressed experimentally by studying reaction rates of dissolution and oxidation of basaltic minerals, and by identifying reaction products forming on the mineral surfaces. Results for the oxidation of pyrrhotite and dissolved ferrous iron are reported.

  2. Atomic force microscopy of differential weathering in real time

    SciTech Connect

    Heaton, J.S.; Engstrom, R.C. . Dept. of Chemistry)

    1994-04-01

    Differential weathering of a rock sample was observed in-situ using atomic force microscopy (AFM). The sample contained fayalite intergrown with veins of magnetite and serpentine. Analyses consisted of polishing the sample with alumina and recording AFM scans periodically during subsequent exposure to nitric acid. Immediately after polishing, serpentine areas were recessed compared to fayalite and magnetite, which were similar in height. As weathering proceeded, both serpentine and magnetite areas protruded from the fayalite surface, and no significant change in the relative heights of magnetite and serpentine features was observed. This suggests that serpentine is less resistant to mechanical weathering than fayalite or magnetite but that serpentine and magnetite are both more resistant to chemical weathering than fayalite. Differential weathering rates between fayalite and magnetite, on the order of a few unit cells per minute, were determined in various nitric acid concentrations by measuring the difference in height between the two minerals as a function of time. A dissolution rate law for fayalite was determined by comparing the rates for different concentrations of nitric acid and assuming the dissolution of magnetite was negligible compared to that of fayalite. The rate law from this study is Rate = 7.7* [HNO[sub 3

  3. Weather Fundamentals: Hurricanes & Tornadoes. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) features information on the deadliest and most destructive storms on Earth. Through satellite…

  4. Regional-seasonal weather forecasting

    SciTech Connect

    Abarbanel, H.; Foley, H.; MacDonald, G.; Rothaus, O.; Rudermann, M.; Vesecky, J.

    1980-08-01

    In the interest of allocating heating fuels optimally, the state-of-the-art for seasonal weather forecasting is reviewed. A model using an enormous data base of past weather data is contemplated to improve seasonal forecasts, but present skills do not make that practicable. 90 references. (PSB)

  5. Weather Fundamentals: Rain & Snow. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) gives concise explanations of the various types of precipitation and describes how the water…

  6. Weather to Make a Decision

    ERIC Educational Resources Information Center

    Hoyle, Julie E.; Mjelde, James W.; Litzenberg, Kerry K.

    2006-01-01

    DECIDE is a teacher-friendly, integrated approach designed to stimulate learning by allowing students to make decisions about situations they face in their lives while using scientific weather principles. This learning unit integrates weather science, decision theory, mathematics, statistics, geography, and reading in a context of decision…

  7. The pioneers of weather forecasting

    NASA Astrophysics Data System (ADS)

    Ballard, Susan

    2016-01-01

    In The Weather Experiment author Peter Moore takes us on a compelling journey through the early history of weather forecasting, bringing to life the personalities, lives and achievements of the men who put in place the building blocks required for forecasts to be possible.

  8. Aviation Weather Information Requirements Study

    NASA Technical Reports Server (NTRS)

    Keel, Byron M.; Stancil, Charles E.; Eckert, Clifford A.; Brown, Susan M.; Gimmestad, Gary G.; Richards, Mark A.; Schaffner, Philip R. (Technical Monitor)

    2000-01-01

    The Aviation Safety Program (AvSP) has as its goal an improvement in aviation safety by a factor of 5 over the next 10 years and a factor of 10 over the next 20 years. Since weather has a big impact on aviation safety and is associated with 30% of all aviation accidents, Weather Accident Prevention (WxAP) is a major element under this program. The Aviation Weather Information (AWIN) Distribution and Presentation project is one of three projects under this element. This report contains the findings of a study conducted by the Georgia Tech Research Institute (GTRI) under the Enhanced Weather Products effort, which is a task under AWIN. The study examines current aviation weather products and there application. The study goes on to identify deficiencies in the current system and to define requirements for aviation weather products that would lead to an increase in safety. The study also provides an overview the current set of sensors applied to the collection of aviation weather information. New, modified, or fused sensor systems are identified which could be applied in improving the current set of weather products and in addressing the deficiencies defined in the report. In addition, the study addresses and recommends possible sensors for inclusion in an electronic pilot reporting (EPIREP) system.

  9. Feasibility and Implications of a Rock Coating Catena: Analysis of a Desert Hillslope

    NASA Astrophysics Data System (ADS)

    Palmer, Ronald E.

    2002-08-01

    This research analyzes rock coatings on a basaltic hill in the western Mojave Desert using a combination of aerial imagery, a new method of digital in-field ground-based image processing, and statistical analyses. In addition, this research resulted in the development of a new rock coating index (RCI) to generalize changes in rock coatings along a slope, applied here to 2,760 individual clasts. RCI values reveal variations of different types of rock coatings on different particle sizes, in this case rock varnish, iron films, and rocks eroding too fast to host any coating. Larger particles host more rock varnish, iron films do not prefer a particular particle size, and highly weathered no-coating rocks are relatively smaller.

  10. Infrared spectroscopy of weathering products in a terrestrial glacial environment: Implications for cold weathering on planetary surfaces

    NASA Astrophysics Data System (ADS)

    Rutledge, A. M.; Christensen, P. R.; Havig, J. R.

    2011-12-01

    Geologic features on Mars show evidence of modification by water and water ice. Past obliquity variations are hypothesized to have allowed the formation and stability of ground ice near the equator, possibly promoting the accumulation of glaciers. Massive ice deposits, including probable glacial and periglacial features have also been observed in the east Hellas Basin and Deuteronilus Mensae regions, located at the midlatitudes of Mars. These features indicate present-day, near-surface ice has been in contact with geologic materials, creating an environment in which cold weathering processes could have been occurring, and might still be at work. Weathering processes in cold terrestrial environments are not well understood, and processes acting on subglacial and englacial sediments and rocks are not well characterized due to the remote location of many glaciers and the difficulty of collecting samples. The types of weathering products and energy sources produced in a glacial environment will drive the overall energy budget for any microbial communities present. The subglacial energy budget for microbes thus has implications in the search for life on other planets, making glacial and periglacial terrains excellent sites for future exploration. However, planetary ice deposits are difficult to study due to their sensitive nature and are thus limited to observation from orbit at present. It is therefore a key concern to better understand the types materials and alteration products that can be observed and constrained from orbital data. In this study, we characterize the types of weathering products present in a glacial system using ground-truthed remote sensing techniques. Robertson Glacier, Alberta, Canada (115°20'W, 50°44'N) provides an excellent testbed for this technique as it is accessible, and its recent and continuing retreat allows fresh subglacial and englacial sediments to be sampled. Samples of bedrock and glacially altered rock and sediments were collected

  11. Physical weathering and modification of a rhyolitic hyaloclastite in Iceland

    NASA Astrophysics Data System (ADS)

    de Vet, S. J.; Mittelmeijer-Hazeleger, M. C.; Braakhekke, J. J. M.; Cammeraat, L. H.

    2014-06-01

    Fragmental volcanic glass or `hyaloclastite' is a common glaciovolcanic eruption product that is formed in large abundance during basaltic, andesitic and rhyolitic subglacial eruptions. The physical weathering of rhyolitic hyaloclastites differs notably from basaltic hyaloclastites due to differences in cementation and edifice consolidation. As rhyolitic glasses are also much rarer, comparatively little is known about their physical weathering and fracturing characteristics. In the presented study, we provide a process-oriented analysis of the physical modification of subglacially erupted rhyolitic hyaloclastites from the Bláhnúkur edifice in Torfajökull (Iceland). Frost weathering experiments were performed to determine how vesicular glass particles fragment to finer particle sizes. The surficial porosity of the glass drives such frost weathering through the process of pore pressurisation and was quantified using high-pressure mercury intrusion. Uniaxial compression experiments were carried out to understand how the glass structure responds to the application of external stress. The observed fracturing in both experimental treatments was found to adhere to fractal statistics, which allowed the compression experiments to be used in conjunction with the frost weathering experiments for inferring the fracturing characteristics of rhyolitic volcanic glasses. Transport processes by wind and gravity were simulated by long-duration abrasion experiments in rock tumblers (through granular avalanching), but these low-energy particle interactions were not found to significantly abrade particles. A notable result from our fragmentation experiments was the production of <10 μm particles. This size range is considered respirable and illustrates how physical weathering can continuously create potentially harmful ash textures; a process which is often overlooked in health hazard assessments after volcanic eruptions. Fragmentation by post-eruptive weathering can lead to

  12. Upgrade Summer Severe Weather Tool

    NASA Technical Reports Server (NTRS)

    Watson, Leela

    2011-01-01

    The goal of this task was to upgrade to the existing severe weather database by adding observations from the 2010 warm season, update the verification dataset with results from the 2010 warm season, use statistical logistic regression analysis on the database and develop a new forecast tool. The AMU analyzed 7 stability parameters that showed the possibility of providing guidance in forecasting severe weather, calculated verification statistics for the Total Threat Score (TTS), and calculated warm season verification statistics for the 2010 season. The AMU also performed statistical logistic regression analysis on the 22-year severe weather database. The results indicated that the logistic regression equation did not show an increase in skill over the previously developed TTS. The equation showed less accuracy than TTS at predicting severe weather, little ability to distinguish between severe and non-severe weather days, and worse standard categorical accuracy measures and skill scores over TTS.

  13. Smooth Sailing for Weather Forecasting

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Through a cooperative venture with NASA's Stennis Space Center, WorldWinds, Inc., developed a unique weather and wave vector map using space-based radar satellite information and traditional weather observations. Called WorldWinds, the product provides accurate, near real-time, high-resolution weather forecasts. It was developed for commercial and scientific users. In addition to weather forecasting, the product's applications include maritime and terrestrial transportation, aviation operations, precision farming, offshore oil and gas operations, and coastal hazard response support. Target commercial markets include the operational maritime and aviation communities, oil and gas providers, and recreational yachting interests. Science applications include global long-term prediction and climate change, land-cover and land-use change, and natural hazard issues. Commercial airlines have expressed interest in the product, as it can provide forecasts over remote areas. WorldWinds, Inc., is currently providing its product to commercial weather outlets.

  14. International Space Weather Initiative (ISWI)

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Davila, Joseph M.

    2010-01-01

    The International Space Weather Initiative (ISWI) is an international scientific program to understand the external drivers of space weather. The science and applications of space weather has been brought to prominence because of the rapid development of space based technology that is useful for all human beings. The ISWI program has its roots in the successful International Heliophysical Year (IHY) program that ran during 2007 - 2009. The primary objective of the ISWI program is to advance the space weather science by a combination of instrument deployment, analysis and interpretation of space weather data from the deployed instruments in conjunction with space data, and communicate the results to the public and students. Like the IHY, the ISWI will be a grass roots organization with key participation from national coordinators in cooperation with an international steering committee. This talk outlines the ISWI program including its organization and proposed activities.

  15. Public Awareness of Space Weather

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Louis J.

    2009-08-01

    As society increasingly relies on space-based infrastructure for communication and national security, there is a growing need to improve public awareness of the risks space weather poses. The National Space Weather Program (NSWP) should consider this need as it develops new strategic plans. The 2006 “Report of the Assessment Committee for the National Space Weather Program” (http://www.ofcm.gov/r24/fcm-r24.htm) continues to guide this important national program, which aims to improve space weather forecasting services and reduce technological vulnerabilities. NSWP, under the auspices of the Office of the Federal Coordinator for Meteorology (OFCM), is coordinated by the NSWP Council, which consists of eight federal agencies. This council, through its Committee for Space Weather, is in the process of formulating new Strategic and Implementation plans for the NSWP using recommendations from the Assessment Committee.

  16. Iron-sulfur mineralogy of Mars - Magmatic evolution and chemical weathering products

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.; Fisher, Duncan S.

    1990-01-01

    Models are developed for the magmatic evolution and the oxidative weathering of sulfide minerals on Mars, based on petrogenetic associations among komatiitic rock types, Viking geochemical data, SNC meteorites, and terrestrial Fi-Ni deposits. The weathering model was tested by exposing komatiitic pyrrhotites and olivines to sulfuric acid solutions, with or without dissolved ferric iron, and identifying the reaction products by Moessbauer spectroscopy. The results suggest that, on Mars, acidic groundwater has induced oxidative weathering of pyrrhotite, yielding FeS2 and then FeOOH.

  17. PV powering a weather station for severe weather

    SciTech Connect

    Young, W. Jr.; Schmidt, J.

    1997-12-31

    A natural disaster, such as Hurricane Andrew, destroys thousands of homes and businesses. The destruction from this storm left thousands of people without communications, potable water, and electrical power. This prompted the Florida Solar Energy Center to study the application of solar electric power for use in disasters. During this same period, volunteers at the Tropical Prediction Center at the National Hurricane Center (NHC), Miami, Florida and the Miami Office of the National Weather Service (NWS) were working to increase the quantity and quality of observations received from home weather stations. Forecasters at NHC have found surface reports from home weather stations a valuable tool in determining the size, strength and course of hurricanes. Home weather stations appear able to record the required information with an adequate level of accuracy. Amateur radio, utilizing the Automatic Packet Report System, (APRS) can be used to transmit this data to weather service offices in virtually real time. Many weather data collecting stations are at remote sites which are not readily serviced by dependable commercial power. Photovoltaic (solar electric) modules generate electricity and when connected to a battery can operate as a stand alone power system. The integration of these components provides an inexpensive standalone system. The system is easy to install, operates automatically and has good communication capabilities. This paper discusses the design criteria, operation, construction and deployment of a prototype solar powered weather station.

  18. The weathering of micrometeorites from the Transantarctic Mountains

    NASA Astrophysics Data System (ADS)

    van Ginneken, Matthias; Genge, Matthew J.; Folco, Luigi; Harvey, Ralph P.

    2016-04-01

    Micrometeorites are cosmic dust particles recovered from the Earth's surface that dominate the influx of extraterrestrial material accreting to our planet. This paper provides the first in-depth study of the weathering of micrometeorites within the Antarctic environment that will allow primary and secondary features to be distinguished. It is based on the analysis of 366 particles from Larkman Nunatak and 25 from the Transantarctic Mountain collection. Several important morphological categories of weathering effects were identified: (1) irregular and faceted cavities, (2) surface etch pits, (3) infilled cavities, (4) replaced silicate phases, and (5) hydrated and replaced metal. These features indicate that congruent dissolution of silicate phases, in particular olivine, is important in generating new pore space within particles. Comparison of the preservation of glass and olivine also indicates preferential dissolution of olivine by acidic solutions during low temperature aqueous alteration. Precipitation of new hydrous phases within cavities, in particular ferrihydrite and jarosite, results in pseudomorph textures within heavily altered particles. Glass, in contrast, is altered to palagonite gels and shows a sequential replacement indicative of varying water to rock ratios. Metal is variably replaced by Fe-oxyhydroxides and results in decreases in Ni/Fe ratio. In contrast, sulphides within metal are largely preserved. Magnetite, an essential component of micrometeorites formed during atmospheric entry, is least altered by interaction with the terrestrial environment. The extent of weathering in the studied micrometeorites is sensitive to differences in their primary mineralogy and varies significantly with particle type. Despite these differences, we propose a weathering scale for micrometeorites based on both their degree of terrestrial alteration and the level of encrustation by secondary phases. The compositions and textures of weathering products, however

  19. High potential for chemical weathering and climate effects of early lichens and bryophytes in the Late Ordovician

    NASA Astrophysics Data System (ADS)

    Porada, Philipp; Lenton, Tim; Pohl, Alexandre; Weber, Bettina; Mander, Luke; Donnadieu, Yannick; Beer, Christian; Pöschl, Ulrich; Kleidon, Axel

    2016-04-01

    Non-vascular vegetation in the Late Ordovician may have considerably increased global chemical weathering, thereby reducing atmospheric CO2 concentration and contributing to a decrease in global temperature and the onset of glaciations. Usually, enhancement of weathering by non-vascular vegetation is estimated using field experiments which are limited to small areas and a low number of species. This makes it difficult to extrapolate to the global scale and to climatic conditions of the past, which differ markedly from the recent climate. Here we present a global, spatially explicit modelling approach to estimate chemical weathering by non-vascular vegetation in the Late Ordovician. During this period, vegetation probably consisted of early forms of today's lichens and bryophytes. We simulate these organisms with a process-based model, which takes into account their physiological diversity by representing multiple species. The productivity of lichens and bryophytes is then related to chemical weathering of surface rocks. The rationale is that the organisms dissolve rocks to extract phosphorus for the production of new biomass. To account for the limited supply of unweathered rock material in shallow regions, we cap biotic weathering at the erosion rate. We estimate a potential global weathering flux of 10.2 km3 yr‑1 of rock, which is around 12 times larger than today's global chemical weathering. The high weathering potential implies a considerable impact of lichens and bryophytes on atmospheric CO2 concentration in the Ordovician. Moreover, we find that biotic weathering is highly sensitive to atmospheric CO2, which suggests a strong feedback between chemical weathering by lichens and bryophytes and climate.

  20. Weather Data Receiver

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Northern Video Graphics, Inc. developed a low-cost satellite receiving system for users such as independent meteorologists, agribusiness firms, small airports or flying clubs, marine vessels and small TV stations. Called Video Fax, it is designed for use with certain satellites; the GOES (Geostationary Operational Environmental Satellite) spacecraft operated by the National Oceanic and Atmospheric Administration, the European Space Agency's Meteosat and Japan's Geostationary Meteorological Satellite. By dictum of the World Meteorological Organization, signals from satellites are available to anyone without cost so the Video Fax user can acquire signals directly from the satellite and cut out the middle man, enabling savings. Unit sells for about one-fifth the cost of the equipment used by TV stations. It consists of a two-meter antenna; a receiver; a microprocessor-controlled display computer; and a video monitor. Computer stores data from the satellites and converts it to an image which is displayed on the monitor. Weather map can be preserved as signal data on tape, or it can be stored in a video cassette as a permanent image.

  1. Global ionospheric weather

    SciTech Connect

    Decker, D.T.; Doherty, P.H.

    1994-02-28

    In the last year, the authors have studied several issues that are critical for understanding ionospheric weather. Work on global F-region modeling has consisted of testing the Phillips Laboratory Global Theoretical Ionosphere Model. Comparisons with both data and other theoretical models have been successfully conducted and are ongoing. GPS observations, as well as data analysis, are also ongoing. Data have been collected for a study on the limitations in making absolute ionospheric measurements using GPS. Another study on ionospheric variability is the first of its kind using GPS data. The observed seasonal total electron content behavior is consistent with that determined from the Faraday rotation technique. Work on the FAA's Phase 1 Wide Area Differential GPS (WADGPS) Satellite Navigation Testbed Experiment also continues. Initial results indicate that stations using operational WADGPS should be located no greater than 430 km apart. Work comparing the authors electron-proton-H atom model to both observations and other models has been generally successful. They have successfully modeled the creation of high-latitude large-scale plasma structures using two separate mechanisms (time-varying global convection and meso-scale convection events).

  2. Geochemical and tectonic uplift controls on rock nitrogen inputs across terrestrial ecosystems

    NASA Astrophysics Data System (ADS)

    Morford, Scott L.; Houlton, Benjamin Z.; Dahlgren, Randy A.

    2016-02-01

    Rock contains > 99% of Earth's reactive nitrogen (N), but questions remain over the direct importance of rock N weathering inputs to terrestrial biogeochemical cycling. Here we investigate the factors that regulate rock N abundance and develop a new model for quantifying rock N mobilization fluxes across desert to temperate rainforest ecosystems in California, USA. We analyzed the N content of 968 rock samples from 531 locations and compiled 178 cosmogenically derived denudation estimates from across the region to identify landscapes and ecosystems where rocks account for a significant fraction of terrestrial N inputs. Strong coherence between rock N content and geophysical factors, such as protolith, (i.e. parent rock), grain size, and thermal history, are observed. A spatial model that combines rock geochemistry with lithology and topography demonstrates that average rock N reservoirs range from 0.18 to 1.2 kg N m-3 (80 to 534 mg N kg-1) across the nine geomorphic provinces of California and estimates a rock N denudation flux of 20-92 Gg yr-1 across the entire study area (natural atmospheric inputs ~ 140 Gg yr-1). The model highlights regional differences in rock N mobilization and points to the Coast Ranges, Transverse Ranges, and the Klamath Mountains as regions where rock N could contribute meaningfully to ecosystem N cycling. Contrasting these data to global compilations suggests that our findings are broadly applicable beyond California and that the N abundance and variability in rock are well constrained across most of the Earth system.

  3. Conversion of bedrock to soil and feedback processes between the surface and the weathering front in a deeply weathered regolith, Central Sri Lankan Highlands

    NASA Astrophysics Data System (ADS)

    Behrens, Ricarda; Bouchez, Julien; Schuessler, Jan A.; Dultz, Stefan; Hewawasam, Tilak; von Blanckenburg, Friedhelm

    2014-05-01

    In the Sri Lankan highlands denudation rates and chemical weathering rates represent the low-end-member in global weathering rates [1, 2]. Here we explore the causes for these low rates by a detailed soil-mineralogical study of a highly weathered deep saprolite profile developed from charnockite bedrock. Spheroidal weathering of the bedrock characterized the weathering front where rounded corestones are produced at the rock-saprolite interface. The first mineral attacked by weathering was found to be pyroxene but plagioclase is the first mineral depleted to near-completion at the corestone-saprolite-boundary. Weathering of pyroxene is initiated by in situ iron oxidation, leading to an increase of porosity due to micro-cracking [3]. The accrued micro cracks allow for fluid transport and the dissolution of biotite and plagioclase. The strong plagioclase weathering leads to formation of high secondary porosity over a small distance and the final disaggregation of bedrock to saprolite. Sequential extraction showed that the first secondary phases are amorphous oxides from which secondary minerals (gibbsite, kaolinite, goethite and minor amounts of smectites) precipitate. Modeling of the strain formation due to increasing volume during iron oxidation in pyroxene and biotite showed that spheroidal weathering can be explained with this process only if the formation of secondary porosity, due to a negative volume budget during primary mineral weathering to secondary phases, occurs. As oxidation is the first occurring reaction, O2 is a rate limiting factor for chemical weathering in this setting. Hence the supply of oxygen and the consumption at depth connects processes at the weathering front with those at the surface as a feedback mechanism. Advective and diffusive transport modeling shows that the feedback will be much more pronounced with dominating diffusive transport. Due to the low porosity of the bedrock the O2 transport in the pristine bedrock occurs via diffusion

  4. The Rock Physics Handbook

    NASA Astrophysics Data System (ADS)

    Mavko, Gary; Mukerji, Tapan; Dvorkin, Jack

    2003-10-01

    The Rock Physics Handbook conveniently brings together the theoretical and empirical relations that form the foundations of rock physics, with particular emphasis on seismic properties. It also includes commonly used models and relations for electrical and dielectric rock properties. Seventy-six articles concisely summarize a wide range of topics, including wave propagation, AVO-AVOZ, effective media, poroelasticity, pore fluid flow and diffusion. The book contains overviews of dispersion mechanisms, fluid substitution, and Vp-Vs relations. Useful empirical results on reservoir rocks and sediments, granular media, tables of mineral data, and an atlas of reservoir rock properties complete the text. This distillation of an otherwise scattered and eclectic mass of knowledge is presented in a form that can be immediately applied to solve real problems. Geophysics professionals, researchers and students as well as petroleum engineers, well log analysts, and environmental geoscientists will value The Rock Physics Handbook as a unique resource.

  5. Cold-Weather Sports and Your Family

    MedlinePlus

    ... 5 Things to Know About Zika & Pregnancy Cold-Weather Sports and Your Family KidsHealth > For Parents > Cold- ... once the weather turns frosty. Beating the Cold-Weather Blahs Once a chill is in the air, ...

  6. Subsurface Evolution: Weathering and Mechanical Strength Reduction in Bedrock of Lower Gordon Gulch, Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Kelly, P. J.; Anderson, S. P.; Anderson, R. S.; Blum, A.; Foster, M. A.; Langston, A. L.

    2011-12-01

    Weathering processes drive mobile regolith production at the surface of the earth. Chemical and physical weathering weakens rock by creating porosity, opening fractures, and transforming minerals. Increased porosity provides habitat for living organisms, which aid in further breakdown of the rock, leaving it more susceptible to displacement and transport. In this study, we test mechanical and chemical characteristics of weathered profiles to better understand weathering processes. We collect shallow bedrock cores from tors and isovolumetrically weathered bedrock in lower Gordon Gulch to characterize the mechanical strength, mineralogy, and bulk chemistry of samples to track changes in the subsurface as bedrock weathers to mobile regolith. Gordon Gulch is a small (2.7 km2), E-W trending catchment within the Boulder Creek Critical Zone Observatory underlain by Pre-Cambrian gneiss and granitic bedrock. The basin is typical of the "Rocky Mountain Surface" of the Front Range, characterized by low relief, a lack of glacial or fluvial incision, and deep weathering. Although the low-curvature, low-relief Rocky Mountain Surface would appear to indicate a landscape roughly in steady-state, shallow seismic surveys (Befus et al., 2011, Vadose Zone Journal) indicate depth to bedrock is highly variable. Block style release of saprolite into mobile regolith could explain this high variability and should be observable in geotechnical testing. Gordon Gulch also displays a systematic slope-aspect dependent control on weathering, with N-facing hillslopes exhibiting deeper weathering profiles than the S-facing hillslope. We believe comparisons of paired geotechnical-testing, XRD, and XRF analyses may explain this hillslope anisotropy. Rock quality designation (RQD) values, a commonly used indicator of rock mass quality (ASTM D6032), from both N- and S- facing aspects in Gordon Gulch indicate that granitic bedrock in both outcrop and saprolitic rock masses is poor to very poor

  7. Why is there no Universal Law for Rock Wall Retreat?

    NASA Astrophysics Data System (ADS)

    Krautblatter, Michael; Moore, Jeffrey

    2016-04-01

    Comparing studies of rock slope erosion and soil slope erosion, we find no governing equation similar to the universal soil loss equation for rock slopes. Rock masses in contact with the atmosphere are affected by a suite of physical, chemical and biological processes which degrade intact rock, creating new fractures and extending existing flaws. Complex feedbacks must be explored between changing slope boundary conditions, stress redistribution and fracturing, and weathering by external mechanisms. Rock slope systems are distinguished from soil slope systems by the fundamental nonlinear properties of rock masses. Rock masses represent discontinuous, inhomogeneous, anisotropic, and nonlinearly elastic materials, and contain a record of millions of years of thermal, hydrological, mechanical and chemical (THMC) processes. The origin and evolution of rock mass strength over time can significantly affect bedrock erodibility and engineering performance, the study of which represents a major chance and challenge for the geoscience community. The imprint of THMC processes on rock properties begins with the geological genesis of rocks; however, a significant degree of material behaviour evolves coincidently with the exhumation and evolution of topography. Thus, fracture generation has been investigated as the result of the environmental stress history in geology and geomorphology, partly modulated by incision and topographic stress evolution. Resultant fracture patterns control the degree of discontinuity heterogeneity, anisotropy, and nonlinear mechanical behaviour over millions of years. Here we discuss important novel conceptual approaches to temporally and spatially decipher nonlinear effects on rock slope erosion including incision-related topographic stresses, rock fatigue, paraglacial and paracratering effects etc. and how they could contribute to a more uniform understanding of rockwall retreat.

  8. Lithium isotopes in large rivers reveal the cannibalistic nature of modern continental weathering and erosion

    NASA Astrophysics Data System (ADS)

    Dellinger, Mathieu; Gaillardet, Jérôme; Bouchez, Julien; Calmels, Damien; Galy, Valier; Hilton, Robert G.; Louvat, Pascale; France-Lanord, Christian

    2014-09-01

    The erosion of major mountain ranges is thought to be largely cannibalistic, recycling sediments that were deposited in the ocean or on the continents prior to mountain uplift. Despite this recognition, it has not yet been possible to quantify the amount of recycled material that is presently transported by rivers to the ocean. Here, we have analyzed the Li content and isotope composition (δLi7) of suspended sediments sampled along river depth profiles and bed sands in three of the largest Earth's river systems (Amazon, Mackenzie and Ganga-Brahmaputra rivers). The δLi7 values of river-sediments transported by these rivers range from +5.3 to -3.6‰ and decrease with sediment grain size. We interpret these variations as reflecting a mixture of unweathered rock fragments (preferentially transported at depth in the coarse fraction) and present-day weathering products (preferentially transported at the surface in the finest fraction). Only the finest surface sediments contain the complementary reservoir of Li solubilized by water-rock interactions within the watersheds. Li isotopes also show that river bed sands can be interpreted as a mixture between unweathered fragments of igneous and sedimentary rocks. A mass budget approach, based on Li isotopes, Li/Al and Na/Al ratios, solved by an inverse method allows us to estimate that, for the large rivers analyzed here, the part of solid weathering products formed by present-day weathering reactions and transported to the ocean do not exceed 35%. Li isotopes also show that the sediments transported by the Amazon, Mackenzie and Ganga-Brahmaputra river systems are mostly sourced from sedimentary rocks (>60%) rather than igneous rocks. This study shows that Li isotopes in the river particulate load are a good proxy for quantifying both the erosional rock sources and the fingerprint of present-day weathering processes. Overall, Li isotopes in river sediments confirm the cannibalistic nature of erosion and weathering.

  9. Friction of rocks

    USGS Publications Warehouse

    Byerlee, J.

    1978-01-01

    Experimental results in the published literature show that at low normal stress the shear stress required to slide one rock over another varies widely between experiments. This is because at low stress rock friction is strongly dependent on surface roughness. At high normal stress that effect is diminished and the friction is nearly independent of rock type. If the sliding surfaces are separated by gouge composed of Montmorillonite or vermiculite the friction can be very low. ?? 1978 Birkha??user Verlag.

  10. Weathering processes as predisposing factors of the landscape evolution along plutono-metamorphic profiles of the Sila Massif, Calabria, southern Italy

    NASA Astrophysics Data System (ADS)

    Perri, Francesco; Borrelli, Luigi; Muto, Francesco; Gullà, Giovanni; Critelli, Salvatore; Conforti, Massimo; Filomena, Luciana; Rago, Valeria

    2013-04-01

    This work is aimed to join interdisciplinary research topics of weathering profile stages on plutonic (granitoid) and metamorphic (gneissic) rocks related to tectonic and landscape evolution of the western Sila Grande Massif (southern Italy). The grain-size of the studied samples is related to the parent rocks in response to physical and chemical weathering processes. Weathering processes produce an unconsolidated rock characterized by sand-gravel grain-size fraction for the granitoid rocks and by sand-silt grain-size fraction for the gneissic rocks. Chemical and mineralogical analyses confirm the granulometric observations. The difference between granitoid and gneissic rocks are mainly related to a higher content of quartz and feldspars for the first one rock type, whereas the second rock type shows higher content of neoformed clay minerals as well expandable phases. The main mineralogical changes concern the partial transformation of biotite and the partial destruction of feldspars, associated with the neoformation of secondary minerals (clay minerals and Fe-oxides) during the most advanced weathering stage; these processes also produce a substitution of the original rock fabric. All these petrological, chemical and mineralogical observations associated to microfractures and morphological variations occur on both plutonic and metamorphic original rocks and, thereby, affect the surrounding landscape processes. Generally, the granitoid profiles are regular and simple, characterized by gradual variation in the degree of weathering from bottom to top; where granitoid rocks show strong morphologies characterized by high relief energy and steep slopes, earth and debris slides, soil slips and earth flow can occur especially when fresher granitoids is near the surface and is covered by organic debris, colluvium, or soil. The gneissic profiles are characterized by structural complexity may be related to several factors such as presence of faults, high state of fracturing

  11. Stormy weather in galaxy clusters

    PubMed

    Burns

    1998-04-17

    Recent x-ray, optical, and radio observations coupled with particle and gas dynamics numerical simulations reveal an unexpectedly complex environment within clusters of galaxies, driven by ongoing accretion of matter from large-scale supercluster filaments. Mergers between clusters and continuous infall of dark matter and baryons from the cluster periphery produce long-lived "stormy weather" within the gaseous cluster atmosphere-shocks, turbulence, and winds of more than 1000 kilometers per second. This weather may be responsible for shaping a rich variety of extended radio sources, which in turn act as "barometers" and "anemometers" of cluster weather. PMID:9545210

  12. GEM: Statistical weather forecasting procedure

    NASA Technical Reports Server (NTRS)

    Miller, R. G.

    1983-01-01

    The objective of the Generalized Exponential Markov (GEM) Program was to develop a weather forecast guidance system that would: predict between 0 to 6 hours all elements in the airways observations; respond instantly to the latest observed conditions of the surface weather; process these observations at local sites on minicomputing equipment; exceed the accuracy of current persistence predictions at the shortest prediction of one hour and beyond; exceed the accuracy of current forecast model output statistics inside eight hours; and be capable of making predictions at one location for all locations where weather information is available.

  13. Space Weather Forecasting: An Enigma

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.

    2012-12-01

    The space age began in earnest on October 4, 1957 with the launch of Sputnik 1 and was fuelled for over a decade by very strong national societal concerns. Prior to this single event the adverse effects of space weather had been registered on telegraph lines as well as interference on early WWII radar systems, while for countless eons the beauty of space weather as mid-latitude auroral displays were much appreciated. These prior space weather impacts were in themselves only a low-level science puzzle pursued by a few dedicated researchers. The technology boost and innovation that the post Sputnik era generated has almost single handedly defined our present day societal technology infrastructure. During the decade following Neil's walk on the moon on July 21, 1969 an international thrust to understand the science of space, and its weather, was in progress. However, the search for scientific understand was parsed into independent "stove pipe" categories: The ionosphere-aeronomy, the magnetosphere, the heliosphere-sun. The present day scientific infrastructure of funding agencies, learned societies, and international organizations are still hampered by these 1960's logical divisions which today are outdated in the pursuit of understanding space weather. As this era of intensive and well funded scientific research progressed so did societies innovative uses for space technologies and space "spin-offs". Well over a decade ago leaders in technology, science, and the military realized that there was indeed an adverse side to space weather that with each passing year became more severe. In 1994 several U.S. agencies established the National Space Weather Program (NSWP) to focus scientific attention on the system wide issue of the adverse effects of space weather on society and its technologies. Indeed for the past two decades a significant fraction of the scientific community has actively engaged in understanding space weather and hence crossing the "stove

  14. Bounce Rock Dimple

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This panoramic camera image shows the hole drilled by the Mars Exploration Rover Opportunity's rock abrasion tool into the rock dubbed 'Bounce' on Sol 65 of the rover's journey. The tool drilled about 7 millimeters (0.3 inches) into the rock and generated small piles of 'tailings' or rock dust around the central hole, which is about 4.5 centimeters (1.7 inches) across. The image from sol 66 of the mission was acquired using the panoramic camera's 430 nanometer filter.

  15. Hungry for Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image from the Mars Exploration Rover Spirit hazard identification camera shows the rover's perspective just before its first post-egress drive on Mars. On Sunday, the 15th martian day, or sol, of Spirit's journey, engineers drove Spirit approximately 3 meters (10 feet) toward its first rock target, a football-sized, mountain-shaped rock called Adirondack (not pictured). In the foreground of this image are 'Sashimi' and 'Sushi' - two rocks that scientists considered investigating first. Ultimately, these rocks were not chosen because their rough and dusty surfaces are ill-suited for grinding.

  16. Opaque rock fragments

    SciTech Connect

    Abhijit, B.; Molinaroli, E.; Olsen, J.

    1987-05-01

    The authors describe a new, rare, but petrogenetically significant variety of rock fragments from Holocene detrital sediments. Approximately 50% of the opaque heavy mineral concentrates from Holocene siliciclastic sands are polymineralic-Fe-Ti oxide particles, i.e., they are opaque rock fragments. About 40% to 70% of these rock fragments show intergrowth of hm + il, mt + il, and mt + hm +/- il. Modal analysis of 23,282 opaque particles in 117 polished thin sections of granitic and metamorphic parent rocks and their daughter sands from semi-arid and humid climates show the following relative abundances. The data show that opaque rock fragments are more common in sands from igneous source rocks and that hm + il fragments are more durable. They assume that equilibrium conditions existed in parent rocks during the growth of these paired minerals, and that the Ti/Fe ratio did not change during oxidation of mt to hm. Geothermometric determinations using electron probe microanalysis of opaque rock fragments in sand samples from Lake Erie and the Adriatic Sea suggest that these rock fragments may have equilibrated at approximately 900/sup 0/ and 525/sup 0/C, respectively.

  17. Basalt weathering in an Arctic Mars-analog site

    NASA Astrophysics Data System (ADS)

    Yesavage, Tiffany; Thompson, Aaron; Hausrath, Elisabeth M.; Brantley, Susan L.

    2015-07-01

    The martian surface has undergone chemical and physical weathering in the past, and these processes may continue intermittently today. To explore whether martian rocks are likely to retain features indicative of weathering, we investigated how basaltic material weathers on Earth. Specifically, we investigated weathering of a Quaternary-aged basaltic flow at the Sverrefjell volcano in Svalbard, above the Arctic Circle. This flow weathered since deglaciation under cold, dry (<400 mm/yr) conditions. We analyzed a ∼75-cm core of regolith for chemical loss and then characterized the mineralogical and morphological properties using electron microscopy (EM), X-ray diffraction (XRD), infrared (IR) spectroscopy and selective chemical dissolution. In addition, we ran colloidal dispersion, wetting/drying, and freeze/thaw experiments. In the regolith, we observed concentrations of short-range ordered (SRO) phases similar to those observed in warmer, wetter volcanic ash soils. IR and EM analyses of the clay-sized fraction were consistent with allophane as the predominant secondary phase. Selective chemical extractions targeting SRO phases indicated lower Al/Si ratios than those observed in volcanic soils reported in warmer localities, which we attribute to Si-rich allophane and/or abundant Si-rich rock coatings. The oxic circumneutral-pH colloidal dispersion experiments mobilized Al, Fe and Ti primarily as 260-415 nm particles and Ca, Mg and Na as solutes. Si was lost both in the colloidal and dissolved forms. Dispersed colloids likely contain allophane and ferrihydrite. Under anoxic conditions, dissolution of Fe oxide cements also released fines. The experiments help to explain elemental loss from the clay-sized regolith fraction at Svalbard: observed depletions in Ca, K, Mg and Na were likely due to solute loss, while particle-reactive Al, Fe, Si and Ti were mostly retained. Wetting/drying was observed to be as effective as freeze/thaw in driving material loss. It is thus

  18. STEREO Space Weather and the Space Weather Beacon

    NASA Technical Reports Server (NTRS)

    Biesecker, D. A.; Webb, D F.; SaintCyr, O. C.

    2007-01-01

    The Solar Terrestrial Relations Observatory (STEREO) is first and foremost a solar and interplanetary research mission, with one of the natural applications being in the area of space weather. The obvious potential for space weather applications is so great that NOAA has worked to incorporate the real-time data into their forecast center as much as possible. A subset of the STEREO data will be continuously downlinked in a real-time broadcast mode, called the Space Weather Beacon. Within the research community there has been considerable interest in conducting space weather related research with STEREO. Some of this research is geared towards making an immediate impact while other work is still very much in the research domain. There are many areas where STEREO might contribute and we cannot predict where all the successes will come. Here we discuss how STEREO will contribute to space weather and many of the specific research projects proposed to address STEREO space weather issues. We also discuss some specific uses of the STEREO data in the NOAA Space Environment Center.

  19. Using rock art as an alternative science pedagogy

    NASA Astrophysics Data System (ADS)

    Allen, Casey D.

    College-level and seventh-grade science students were studied to understand the power of a field index, the Rock Art Stability Index (RASI), for student learning about complex biophysical environmental processes. In order to determine if the studied population was representative, 584 college and seventh-grade students undertook a concept mapping exercise after they had learned basic weathering science via in-class lecture. Of this large group, a subset of 322 college students and 13 seventh-grade students also learned RASI through a field experience involving the analysis of rock weathering associated with petroglyphs. After learning weathering through RASI, students completed another concept map. This was a college population where roughly 46% had never taken a "lab science" course and nearly 22% were from minority (non-white) populations. Analysis of student learning through the lens of actor-network theory revealed that when landscape is viewed as process (i.e. many practices), science education embodies both an alternative science philosophy and an alternative materialistic worldview. When RASI components were analyzed after only lecture, student understanding of weathering displayed little connection between weathering form and weathering process. After using RASI in the field however, nearly all students made illustrative concept maps rich in connections between weathering form and weathering process for all subcomponents of RASI. When taken as an aggregate, and measured by an average concept map score, learning increased by almost 14%, Among college minority students, the average score increase approached 23%. Among female students, the average score increase was 16%. For seventh-grade students, scores increased by nearly 36%. After testing for normalcy with Kolmogorov-Smirnov, t-tests reveal that all of these increases were highly statistically significant at p<0.001. The growth in learning weathering science by minority students, as compared to non

  20. Compute the Weather in Your Classroom.

    ERIC Educational Resources Information Center

    Meier, Beverly

    1988-01-01

    Discusses a weather prediction activity connecting local weather network by computer modem. Describes software for telecommunications, data gathering, preparation work, and instructional procedures. (YP)

  1. Variability of visible and near-infrared spectra of rocks

    NASA Astrophysics Data System (ADS)

    Guo, Xiaofang; Wang, Runsheng; Cheng, Jicheng; Zhang, Zonnggui

    1998-08-01

    Although characteristics of visible and near-infrared spectra (0.4 - 2.5 micrometer) of rocks are dominated by electronic processes and molecular vibration processes that is related to chemical composition and structure of rocks, external behavior of spectra of rocks is adjusted by some factors, such as environmental conditions, physical structure of surface and viewing geometry, etc. The spectra of rocks can vary with the changes of these factors to a certain extent. It is obvious that variability of spectra of ground objects would degrade the interpretability of remote sensing images, and especially degrade the effectiveness of techniques of discriminating rocks based on remote sensing spectral features and spectral indexes to a large extent. To discriminate earth surface mineralogy and lithology more effectively and efficiently by remote sensing, especially by hyperspectral remote sensing, requires a good knowledge of variability of spectra of rocks. This paper describes and analyzes variability of reflectance spectra of rocks sampled in Zhangjiakou district of Hebei Province of China, under different light incident direction and incident angle, viewing direction and viewing angle, surface forms of rocks, grades of samples, and types and extents of weathering, etc.

  2. Martian soil stratigraphy and rock coatings observed in color-enhanced Viking Lander images

    NASA Technical Reports Server (NTRS)

    Strickland, E. L., III

    1979-01-01

    Subtle color variations of martian surface materials were enhanced in eight Viking Lander (VL) color images. Well-defined soil units recognized at each site (six at VL-1 and four at VL-2), are identified on the basis of color, texture, morphology, and contact relations. The soil units at the Viking 2 site form a well-defined stratigraphic sequence, whereas the sequence at the Viking 1 site is only partially defined. The same relative soil colors occur at the two sites, suggesting that similar soil units are widespread on Mars. Several types of rock surface materials can be recognized at the two sites; dark, relatively 'blue' rock surfaces are probably minimally weathered igneous rock, whereas bright rock surfaces, with a green/(blue + red) ratio higher than that of any other surface material, are interpreted as a weathering product formed in situ on the rock. These rock surface types are common at both sites. Soil adhering to rocks is common at VL-2, but rare at VL-1. The mechanism that produces the weathering coating on rocks probably operates planet-wide.

  3. Characteristics of terrestrial basaltic rock populations: Implications for Mars lander and rover science and safety

    NASA Astrophysics Data System (ADS)

    Craddock, Robert A.; Golombek, Matthew P.

    2016-08-01

    We analyzed the morphometry of basaltic rock populations that have been emplaced or affected by a variety of geologic processes, including explosive volcanic eruptions (as a proxy for impact cratering), catastrophic flooding, frost shattering, salt weathering, alluvial deposition, and chemical weathering. Morphometric indices for these rock populations were compared to an unmodified population of rocks that had broken off a solidified lava flow to understand how different geologic processes change rock shape. We found that a majority of rocks have an sphericity described as either a disc or sphere in the Zingg classification system and posit that this is a function of cooling fractures in the basalt (Zingg [1935] Schweiz. Miner. Petrogr. Mitt., 15, 39-140). Angularity (roundness) is the most diagnostic morphometric index, but the Corey Shape Factor (CSF), Oblate-Prolate Index (OPI) and deviation from compactness (D) also sometimes distinguished weathering processes. Comparison of our results to prior analyses of rock populations found at the Mars Pathfinder, Spirit, and Curiosity landing sites support previous conclusions. The observation that the size-frequency distribution of terrestrial rock populations follow exponential functions similar to lander and orbital measurements of rocks on Mars, which is expected from fracture and fragmentation theory, indicates that these distributions are being dominantly controlled by the initial fracture and fragmentation of the basalt.

  4. Microarray Analysis of Microbial Weathering

    NASA Astrophysics Data System (ADS)

    Olsson-Francis, K.; van Houdt, R.; Leys, N.; Mergeay, M.; Cockell, C. S.

    2010-04-01

    Microarray analysis of the heavy metal resistant bacterium, Cupriavidus metallidurans CH34 was used to investigate the genes involved in the weathering. The results demonstrated that large porin and membrane transporter genes were unregulated.

  5. Space weather center in Japan

    NASA Astrophysics Data System (ADS)

    Watari, S.

    2008-11-01

    Progress in information technology has enabled to collecting data in near real-time. This significantly improves our ability to monitor space weather conditions. We deliver information on near real-time space weather conditions via the internet. We have started two collaborations with space weather users. One is a measurement of geomagnetically induced current (GIC) of power grids in collaboration with a Japanese power company. The other concerns radiation hazards for aircrews. The radiation exposure level for aircrews was been determined by the Japanese government by the end of 2005. The proposed upper limit is 5 mSV a year. We are actively seeking ways to contribute to this subject. Our activities at the Japanese space weather center are reported in this paper.

  6. Exercising Safely in Hot Weather

    MedlinePlus

    ... www.nia.nih.gov/Go4Life Exercising Safely in Hot Weather Many people enjoy outdoor activities—walking, gardening, ... older adults and people with health problems. Being hot for too long can cause hyperthermia—a heat- ...

  7. The science of space weather.

    PubMed

    Eastwood, Jonathan P

    2008-12-13

    The basic physics underpinning space weather is reviewed, beginning with a brief overview of the main causes of variability in the near-Earth space environment. Although many plasma phenomena contribute to space weather, one of the most important is magnetic reconnection, and recent cutting edge research in this field is reviewed. We then place this research in context by discussing a number of specific types of space weather in more detail. As society inexorably increases its dependence on space, the necessity of predicting and mitigating space weather will become ever more acute. This requires a deep understanding of the complexities inherent in the plasmas that fill space and has prompted the development of a new generation of scientific space missions at the international level. PMID:18812302

  8. Practical Weathering for Geology Students.

    ERIC Educational Resources Information Center

    Hodder, A. Peter

    1990-01-01

    The design and data management of an activity to study weathering by increasing the rate of mineral dissolution in a microwave oven is described. Data analysis in terms of parabolic and first-order kinetics is discussed. (CW)

  9. Space Weathering Processes on Mercury

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Pieters, C. M.

    2002-01-01

    Like the Moon, Mercury has no atmosphere to protect it from the harsh space environment and therefore it is expected that it will incur the effects of space weathering. These weathering processes are capable of both creating regolith and altering its optical properties. However, there are many important differences between the environments of Mercury and the Moon. These environmental differences will almost certainly affect the weathering processes as well as the products of those processes. It should be possible to observe the effects of these differences in Vis/NIR spectra of the type expected to be returned by MESSENGER. More importantly, understanding these weathering processes and their consequences is essential for evaluating the spectral data returned from MESSENGER and other missions in order to determine the mineralogy and the iron content of the Mercurian surface. Theoretical and experimental work has been undertaken in order to better understand these consequences.

  10. URBAN WET-WEATHER FLOWS

    EPA Science Inventory

    Provides the annual Urban Wet Weather Flow Literture Review for the calendar year 1998 conducted for the Water Environment Federation. It contains hundreds of citations covering the topics of characterization and effects, management, modeling, regulator policies and contol and t...

  11. The International Space Weather Initiative

    NASA Technical Reports Server (NTRS)

    Nat, Gopalswamy; Joseph, Davila; Barbara, Thompson

    2010-01-01

    The International Space Weather Initiative (ISWI) is a program of international cooperation aimed at understanding the external drivers of space weather. The ISWI program has its roots in the successful International Heliophysical Year (IHY) program that ran during 2007 - 2009 and will continue with those aspects that directly affect life on Earth. The primary objective of the ISWI program is to advance the space weather science by a combination of instrument deployment, analysis and interpretation of space weather data from the deployed instruments in conjunction with space data, and communicate the results to the public and students. Like the IHY, the ISWI will be a grass roots organization with key participation from national coordinators in cooperation with an international steering committee. This presentation outlines the ISWI program including its organizational aspects and proposed activities. The ISWI observatory deployment and outreach activities are highly complementary to the CAWSES II activities of SCOSTEP.

  12. Weather data communication and utilization

    NASA Technical Reports Server (NTRS)

    Mcfarland, R. H.; Nickum, J. D.; Mccall, D. L.

    1983-01-01

    The communication of weather data to aircraft is discussed. Problems encountered because of the great quantities of data available and the limited capacity to transfer this via radio link to an aircraft are discussed. Display devices are discussed.

  13. The DLR Project - Weather & Flying

    NASA Astrophysics Data System (ADS)

    Gerz, T.

    2009-09-01

    A project is introduced which aims at (a) providing timely, tailored and concise meteorological information especially for adverse weather as precisely as possible for air traffic control and management, airline operating centres, pilots, and airports, and (b) building automated flight control systems and evasion-manoeuvre methods to minimise the impact of adverse wind and wake conditions on the flight performance of an aircraft. Today ATM and ATC most of the time only react on adverse weather when the disruption has already happened or is just about to happen. A future air traffic management should pro-actively anticipate disruptive weather elements and their time scales well in advance to avoid or to mitigate the impact upon the traffic flow. But "weather” is not a technical problem that can be simply solved. Predicting the weather is a difficult and complex task and only possible within certain limits. It is therefore necessary to observe and forecast the changing state of the atmosphere as precisely and as rapidly as possible. Measures must be taken to minimise the impact of adverse weather or changing weather conditions on air traffic management and tactical manoeuvring, both on ground and onboard the aircraft. Weather and meteorological information (MET in short) is to be considered as an integral part of air traffic management. In 2008, DLR has initiated a major project "Wetter & Fliegen” (German for "Weather and Flying”) to address this inter¬disciplinary challenge. Its goal is to augment safety and efficiency of air transportation, thereby focusing on the two German hub airports in Frankfurt and München. This high-level goal shall be reached by two strands of work: a) The development of an Integrated Terminal Weather Systems (ITWS) for the air¬¬ports at Frankfurt and München to improve the detection and forecast of weather phenomena adversely affecting airport operations, including deep convection (thunderstorms, hail, wind), wake vortex, and

  14. Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data

    USGS Publications Warehouse

    Lanza, Nina L.; Ollila, Ann M.; Cousin, Agnes; Wiens, Roger C.; Clegg, Samuel M.; Mangold, Nicolas; Bridges, Nathan; Cooper, Daniel; Schmidt, Mariek E.; Berger, Jeffrey; Arvidson, Raymond E.; Melikechi, Noureddine; Newsom, Horton E.; Tokar, Robert; Hardgrove, Craig; Mezzacappa, Alissa; Jackson, Ryan S.; Clark, Benton C.; Forni, Olivier; Maurice, Sylvestre; Nachon, Marion; Anderson, Ryan B.; Blank, Jennifer; Deans, Matthew; Delapp, Dorothea; Léveillé, Richard; McInroy, Rhonda; Martinez, Ronald; Meslin, Pierre-Yves; Pinet, Patrick

    2015-01-01

    Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water–rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument (LIBS) onboard Curiosity can be used to both identify and analyze rock surface alteration features. In this study we analyze a terrestrial manganese-rich rock varnish coating on a basalt rock in the laboratory with the ChemCam engineering model to determine the LIBS signature of a natural rock coating. Results show that there is a systematic decrease in peak heights for elements such as Mn that are abundant in the coating but not the rock. There is significant spatial variation in the relative abundance of coating elements detected by LIBS depending on where on the rock surface sampled; this is due to the variability in thickness and spatial discontinuities in the coating. Similar trends have been identified in some martian rock targets in ChemCam data, suggesting that these rocks may have coatings or weathering rinds on their surfaces.

  15. Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data

    NASA Astrophysics Data System (ADS)

    Lanza, Nina L.; Ollila, Ann M.; Cousin, Agnes; Wiens, Roger C.; Clegg, Samuel; Mangold, Nicolas; Bridges, Nathan; Cooper, Daniel; Schmidt, Mariek; Berger, Jeffrey; Arvidson, Raymond; Melikechi, Noureddine; Newsom, Horton E.; Tokar, Robert; Hardgrove, Craig; Mezzacappa, Alissa; Jackson, Ryan S.; Clark, Benton; Forni, Olivier; Maurice, Sylvestre; Nachon, Marion; Anderson, Ryan B.; Blank, Jennifer; Deans, Matthew; Delapp, Dorothea; Léveillé, Richard; McInroy, Rhonda; Martinez, Ronald; Meslin, Pierre-Yves; Pinet, Patrick

    2015-03-01

    Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water-rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument (LIBS) onboard Curiosity can be used to both identify and analyze rock surface alteration features. In this study we analyze a terrestrial manganese-rich rock varnish coating on a basalt rock in the laboratory with the ChemCam engineering model to determine the LIBS signature of a natural rock coating. Results show that there is a systematic decrease in peak heights for elements such as Mn that are abundant in the coating but not the rock. There is significant spatial variation in the relative abundance of coating elements detected by LIBS depending on where on the rock surface sampled; this is due to the variability in thickness and spatial discontinuities in the coating. Similar trends have been identified in some martian rock targets in ChemCam data, suggesting that these rocks may have coatings or weathering rinds on their surfaces.

  16. Space Weathering of Small Bodies

    NASA Astrophysics Data System (ADS)

    McFadden, L. A.

    2002-12-01

    Space weathering is defined as any process that wears away and alters surfaces, here confined to small bodies in the Solar System. Mechanisms which possibly alter asteroid and comet surfaces include solar wind bombardment, UV radiation, cosmic ray bombardment, micrometeorite bombardment. These processes are likely to contribute to surface processes differently. For example, solar wind bombardment would be more important on a body closer to the Sun compared to a comet where cosmic ray bombardment might be a more significant weathering mechanism. How can we measure the effects of space weathering? A big problem is that we don't know the nature of the surface before it was weathered. We are in a new era in the study of surface processes on small bodies brought about by the availability of spatially resolved, color and spectral measurements of asteroids from Galileo and NEAR. What processes are active on which bodies? What physics controls surface processes in different regions of the solar system? How do processes differ on different bodies of different physical and chemical properties? What combinations of observable parameters best address the nature of surface processes? Are there alternative explanations for the observed parameters that have been attributed to space weathering? Should we retain the term, space weathering? How can our understanding of space weathering on the Moon help us understand it on asteroids and comets? Finally, we have to leave behind some presuppositions, one being that there is evidence of space weathering based on the fact that the optical properties of S-type asteroids differs from those of ordinary chondrites.

  17. Calcium isotopes in a proglacial weathering environment: Damma glacier, Switzerland

    NASA Astrophysics Data System (ADS)

    Hindshaw, Ruth S.; Reynolds, Ben C.; Wiederhold, Jan G.; Kretzschmar, Ruben; Bourdon, Bernard

    2010-05-01

    Calcium is a key element in global biogeochemical cycles. It is an essential nutrient and the dissolution of Ca from silicate minerals is intimately linked to the global carbon cycle. Yet relatively few studies have utilized the potential of stable Ca isotopes to directly investigate (as opposed to using Sr isotopes) processes affecting Ca during initial weathering and subsequent cycling within the ecosystem. The Damma glacier fieldsite (Central Swiss Alps) provides an ideal opportunity to study the early stages of silicate weathering processes and is the site of a larger multidisciplinary research project (BigLink). The catchment is underlain by Central Aar granite, which does not contain detectable carbonates. The Damma is a small, glacial catchment (10.7 km2) where the glacier has retreatred since 1850 creating a 1.5 km long chronosequence which spans approximately 150 years of soil development and exhibits a strong vegetation gradient along its length. In order to investigate the biogeochemical Ca cycle in the forefield, extensive sampling of the main reservoirs of Ca was undertaken. Soil samples from two different depths (0-5 and 5-10 cm) were collected at 23 randomly selected sites across the forefield in addition to six bulk rock samples. To further investigate potential fractionation between different soil pools, sequential extractions were performed. Stream water was collected at three different locations in the forefield on a biweekly basis throughout the sampling season, in addition to precipitation (snow and rain) and porewater samples. To investigate the effect of biological cycling on Ca, leaves from Rhododendron ferrugineum were also analysed. Analyses of all samples were performed using a Triton TIMS with a 43Ca-46Ca double spike, after a 4-step chromatographic separation procedure. During this very early stage of weathering, the young soils which have formed were isotopically identical in δ44-42Ca to the rock from which they were derived

  18. Structural control of weathering processes within exhumed granitoids: Compartmentalisation of geophysical properties by faults and fractures

    NASA Astrophysics Data System (ADS)

    Place, J.; Géraud, Y.; Diraison, M.; Herquel, G.; Edel, J.-B.; Bano, M.; Le Garzic, E.; Walter, B.

    2016-03-01

    In the latter stages of exhumation processes, rocks undergo weathering. Weathering halos have been described in the vicinity of structures such as faults, veins or dykes, with a lateral size gradually narrowing with depth, symmetrically around the structures. In this paper, we describe the geophysical characterisation of such alteration patterns on two granitoid outcrops of the Catalan Coastal Ranges (Spain), each of which is affected by one major fault, as well as minor faults and fractures. Seismic, electric and ground penetrating radar surveys were carried out to map the spatial distribution of P-wave velocity, electrical resistivity and to identify reflectors of electromagnetic waves. The analysis of this multi-method and complementary dataset revealed that, at shallow depth, geophysical properties of the materials are compartmentalised and asymmetric with respect to major and subsidiary faults affecting the rock mass. This compartmentalisation and asymmetry both tend to attenuate with depth, whereas the effect of weathering is more symmetric with respect to the major structure of the outcrops. We interpret such compartmentalisation as resulting from the role of hydraulic and mechanical boundaries played by subsidiary faults, which tend to govern both the chemical and physical alterations involved in weathering. Thus, the smoothly narrowing halo model is not always accurate, as weathering halos can be strongly asymmetrical and present highly irregular contours delimiting sharp contrasts of geophysical properties. These results should be considered when investigating and modelling fluid storage and transfer in top crystalline rock settings for groundwater applications, hydrocarbon or geothermal reservoirs, as well as mineral deposits.

  19. Detecting Anthropogenic Disturbance on Weathering and Erosion Processes

    NASA Astrophysics Data System (ADS)

    Vanacker, V.; Schoonejans, J.; Bellin, N.; Ameijeiras-Mariño, Y.; Opfergelt, S.; Christl, M.

    2014-12-01

    Anthropogenic disturbance of natural vegetation can profoundly alter the physical, chemical and biological processes within soils. Rapid removal of topsoil during intense farming can result in an imbalance between soil production through chemical weathering and physical erosion, with direct implications on local biogeochemical cycling. However, the feedback mechanisms between soil erosion, chemical weathering and biogeochemical cycling in response to anthropogenic forcing are not yet fully understood. In this paper, we analyze dynamic soil properties for a rapidly changing anthropogenic landscape in the Spanish Betic Cordillera; and focus on the coupling between physical erosion, soil production and soil chemical weathering. Modern erosion rates were quantified through analysis of sediment deposition volumes behind check dams, and represent catchment-average erosion rates over the last 10 to 50 years. Soil production rates are derived from in-situ produced 10Be nuclide concentrations, and represent long-term flux rates. In each catchment, soil chemical weathering intensities were calculated for two soil-regolith profiles. Although Southeast Spain is commonly reported as the European region that is most affected by land degradation, modern erosion rates are low (140 t ha-1 yr-1). About 50 % of the catchments are losing soils at a rate of less than 60 t km-2 yr-1. Our data show that modern erosion rates are roughly of the same magnitude as the long-term or cosmogenically-derived erosion rates in the Betic Cordillera. Soils developed on weathered metamorphic rocks have no well-developed profile characteristics, and are generally thin and stony. Nevertheless, soil chemical weathering intensities are high; and question the occurrence of past soil truncation.

  20. Weather service upgrade too costly?

    NASA Astrophysics Data System (ADS)

    Bush, Susan

    America needs timely and accurate weather forecasting, said Ernest F. Hollings (D-S.C.), chairman of the Senate Committee on Commerce, Science, and Transportation on National Ocean Policy. Calling the existing warning and forecast system dangerously obsolete, Hollings said that new technology “should dramatically improve the accuracy and timeliness of weather predictions,” as we face the new challenge of bringing the National Weather Service into the 21st century. Hollings' committee heard testimony to consider the modernization of the NWS and pending legislation (S98, S916) on June 18.Major components of the Weather Service Modernization program, according to John A. Knauss, administrator of the National Oceanic and Atmospheric Administration, are the Next Generation Weather Radar (NEXRAD), a new generation of Geostationary Operational Environmental Satellites (GOES-NEXT), the Automated Surface Observing System (ASOS), and the Advanced Weather Interactive Processing System (AWIA). The best defense against severe weather—early warnings—is probably hampered by outdated equipment, he added.

  1. Weather data dissemination to aircraft

    NASA Technical Reports Server (NTRS)

    Mcfarland, Richard H.; Parker, Craig B.

    1990-01-01

    Documentation exists that shows weather to be responsible for approximately 40 percent of all general aviation accidents with fatalities. Weather data products available on the ground are becoming more sophisticated and greater in number. Although many of these data are critical to aircraft safety, they currently must be transmitted verbally to the aircraft. This process is labor intensive and provides a low rate of information transfer. Consequently, the pilot is often forced to make life-critical decisions based on incomplete and outdated information. Automated transmission of weather data from the ground to the aircraft can provide the aircrew with accurate data in near-real time. The current National Airspace System Plan calls for such an uplink capability to be provided by the Mode S Beacon System data link. Although this system has a very advanced data link capability, it will not be capable of providing adequate weather data to all airspace users in its planned configuration. This paper delineates some of the important weather data uplink system requirements, and describes a system which is capable of meeting these requirements. The proposed system utilizes a run-length coding technique for image data compression and a hybrid phase and amplitude modulation technique for the transmission of both voice and weather data on existing aeronautical Very High Frequency (VHF) voice communication channels.

  2. Geomorphology's role in the study of weathering of cultural stone

    NASA Astrophysics Data System (ADS)

    Pope, Gregory A.; Meierding, Thomas C.; Paradise, Thomas R.

    2002-10-01

    Great monumental places—Petra, Giza, Angkor, Stonehenge, Tikal, Macchu Picchu, Rapa Nui, to name a few—are links to our cultural past. They evoke a sense of wonderment for their aesthetic fascination if not for their seeming permanence over both cultural and physical landscapes. However, as with natural landforms, human constructs are subject to weathering and erosion. Indeed, many of our cultural resources suffer from serious deterioration, some natural, some enhanced by human impact. Groups from the United Nations to local civic and tourism assemblies are deeply interested in maintaining and preserving such cultural resources, from simple rock art to great temples. Geomorphologists trained in interacting systems, process and response to thresholds, rates of change over time, and spatial variation of weathering processes and effects are able to offer insight into how deterioration occurs and what can be done to ameliorate the impact. Review of recent literature and case studies presented here demonstrate methodological and theoretical advances that have resulted from the study of cultural stone weathering. Because the stone was carved at a known date to a "baseline" or zero-datum level, some of the simplest methods (e.g., assessing surface weathering features or measuring surface recession in the field) provide useful data on weathering rates and processes. Such data are difficult or impossible to obtain in "natural" settings. Cultural stone weathering studies demonstrate the importance of biotic and saline weathering agents and the significance of weathering factors such as exposure (microclimate) and human impact. More sophisticated methods confirm these observations, but also reveal discrepancies between field and laboratory studies. This brings up two important caveats for conservators and geomorphologists. For the conservator, are laboratory and natural setting studies really analogous and useful for assessing stone damage? For the geomorphologist, does

  3. Chemical weathering and CO₂ consumption in the Lower Mekong River.

    PubMed

    Li, Siyue; Lu, X X; Bush, Richard T

    2014-02-15

    Data on river water quality from 42 monitoring stations in the Lower Mekong Basin obtained during the period 1972-1996 was used to relate solute fluxes with controlling factors such as chemical weathering processes. The total dissolved solid (TDS) concentration of the Lower Mekong varied from 53 mg/L to 198 mg/L, and the median (114 mg/L) was compared to the world spatial median value (127 mg/L). Total cationic exchange capacity (Tz(+)) ranged from 729 to 2,607 μmolc/L, and the mean (1,572 μmolc/L) was 1.4 times higher than the world discharge-weighted average. Calcium and bicarbonate dominated the annual ionic composition, accounting for ~70% of the solute load that equalled 41.2×10(9)kg/y. TDS and major elements varied seasonally and in a predictable way with river runoff. The chemical weathering rate of 37.7t/(km(2)y), with respective carbonate and silicate weathering rates of 27.5t/(km(2) y) (13.8mm/ky) and 10.2t/(km(2) y) (3.8mm/ky), was 1.5 times higher than the global average. The CO2 consumption rate was estimated at 191×10(3)molCO2/(km(2)y) for silicate weathering, and 286×10(3)molCO2/(km(2)y) by carbonate weathering. In total, the Mekong basin consumed 228×10(9)molCO2/y and 152×10(9)molCO2/y by the combined weathering of carbonate and silicate, constituting 1.85% of the global CO2 consumption by carbonate weathering and 1.75% by silicates. This is marginally higher than its contribution to global water discharge ~1.3% and much higher than (more than three-fold) its contribution to world land surface area. Remarkable CO2 consumed by chemical weathering (380×10(9)mol/y) was similar in magnitude to dissolved inorganic carbon as HCO3(-) (370×10(9)mol/y) exported by the Mekong to the South China Sea. In this landscape, atmospheric CO2 consumption by rock chemical weathering represents an important carbon sink with runoff and physical erosion controlling chemical erosion. PMID:24291559

  4. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  5. Welcome to Rock Day

    ERIC Educational Resources Information Center

    Varelas, Maria; Benhart, Jeaneen

    2004-01-01

    At the beginning of the school year, the authors, a first-grade teacher and a teacher educator, worked together to "spice up" the first-grade science curriculum. The teacher had taught the unit Rocks, Sand, and Soil several times, conducting hands-on explorations and using books to help students learn about properties of rocks, but she felt the…

  6. Rock Cycle Roulette.

    ERIC Educational Resources Information Center

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  7. Boulders, biology and buildings: Why weathering is vital to geomorphology (Ralph Alger Bagnold Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Viles, Heather A.

    2015-04-01

    Weathering is vital to geomorphology in three main senses. First, it is vital in the sense of being a fundamental and near-ubiquitous earth surface process without which landscapes would not develop, and which also provides a key link between geomorphology and the broader Earth system. Second, weathering is vital in the sense that, as it is heavily influenced by biotic processes, it demonstrates the importance of life to geomorphology and vice versa. In particular, weathering illustrates the many cross-linkages between microbial ecosystems and geomorphology. Finally, it is vital in the sense that weathering provides an important practical application of geomorphological knowledge. Geomorphologists in recent years have contributed much in terms of improving understanding the deterioration of rocks, stone and other materials in heritage sites and the built environment. This knowledge has also had direct implications for heritage conservation. This lecture reviews recent research on each of these three themes and on their linkages, and sets an integrated research agenda for the future. Weathering as a key process underpinning geomorphology and Earth system science has been the subject of much recent conceptual and empirical research. In particular, conceptual research advances have involved improving conceptualisation of scale issues and process synergies, and understanding weathering in terms of non-linear dynamical systems. Empirical advances have included the development of larger datasets on weathering rates, and the application of a wide range of non-destructive and remote sensing techniques to quantify weathering morphologies on boulder and rock surfaces. In recent years, understanding of the complex linkages between ecology and geomorphology (sometimes called biogeomorphology) has advanced particularly strongly in terms of weathering. For example, the influences of disturbance on biota and weathering have been conceptualised and investigated empirically in a

  8. Layered Rocks in Crater

    NASA Technical Reports Server (NTRS)

    2004-01-01

    19 June 2004 Exposures of layered, sedimentary rock are common on Mars. From the rock outcrops examined by the Mars Exploration Rover, Opportunity, in Meridiani Planum to the sequence in Gale Crater's central mound that is twice the thickness of of the sedimentary rocks exposed by Arizona's Grand Canyon, Mars presents a world of sediment to study. This unusual example, imaged by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), shows eroded layer outcrops in a crater in Terra Tyrrhena near 15.4oS, 270.5oW. Sedimentary rocks provide a record of past climates and events. Perhaps someday the story told by the rocks in this image will be known via careful field work. The image covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from the left.

  9. Experimental geobiology links evolutionary intensification of rooting systems and weathering

    NASA Astrophysics Data System (ADS)

    Quirk, Joe; Beerling, David; Leake, Jonathan

    2016-04-01

    The evolution of mycorrhizal fungi in partnership with early land plants over 440 million years ago led to the greening of the continents by plants of increasing biomass, rooting depth, nutrient demand and capacity to alter soil minerals, culminating in modern forested ecosystems. The later co-evolution of trees and rooting systems with arbuscular mycorrhizal (AM) fungi, together driving the biogeochemical cycling of elements and weathering of minerals in soil to meet subsequent increased phosphorus demands is thought to constitute one the most important biotic feedbacks on the geochemical carbon cycle to emerge during the Phanerozoic, and fundamentally rests on the intensifying effect of trees and their root-associating mycorrhizal fungal partners on mineral weathering. Here I present experimental and field evidence linking these evolutionary events to a mechanistic framework whereby: (1) as plants evolved in stature, biomass, and rooting depth, their mycorrhizal fungal partnerships received increasing amounts of plant photosynthate; (2) this enabled intensification of plant-driven fungal weathering of rocks to release growth-limiting nutrients; (3) in turn, this increased land-to-ocean export of Ca and P and enhanced ocean carbonate precipitation impacting the global carbon cycle and biosphere-geosphere-ocean-atmosphere interactions over the past 410 Ma. Our findings support an over-arching hypothesis that evolution has selected plant and mycorrhizal partnerships that have intensified mineral weathering and altered global biogeochemical cycles.

  10. Types of rocks exposed at the Viking landing sites

    SciTech Connect

    Guinness, E.; Arvidson, R.; Dale-Bannister, M.; Slavney, S.

    1985-01-01

    Spectral estimates derived from Viking Lander multispectral images have been used to investigate the types of rocks exposed at both landing sites, and to infer whether the rocks are primary igneous rocks or weathering products. These analyses should aid interpretations of spectra to be returned from the Visual and Infrared Mapping Spectrometer on the upcoming Mars Observer Mission. A series of gray surfaces on the Landers were used to check the accuracy of the camera preflight calibrations. Results indicate that the pre-flight calibrations for the three color channels are probably correct for all cameras but camera 2 on Lander 1. The calibration for the infrared channels appears to have changed, although the cause is not known. For this paper, only the color channels were used to derive data for rocks. Rocks at both sites exhibit a variety of reflectance values. For example, reflectance estimates for two rocks in the blue (0.4-0.5 microns), green (0.5-0.6 microns), and red (0.6-0.75 microns) channels are 0.16, 0.23, and 0.33 and 0.12, 0.19, 0.37 at a phase angle of 20 degrees. These values have been compared with laboratory reflectance spectra of analog materials and telescopic spectra of Mars, both convolved to the Lander bandpasses. Lander values for some rocks are similar to earth based observations of martian dark regions and with certain mafic igneous rocks thinly coated with amorphous ferric-oxide rich weathering products. These results are consistent with previous interpretations.

  11. Experiments and Spectral Studies of Martian Volcanic Rocks: Implications for the Origin of Pathfinder Rocks and Soils

    NASA Technical Reports Server (NTRS)

    Rutherford, Malcolm J.; Mustard, Jack; Weitz, Catherine

    2002-01-01

    The composition and spectral properties of the Mars Pathfinder rocks and soils together with the identification of basaltic and andesitic Mars terrains based on Thermal Emission Spectrometer (TES) data raised interesting questions regarding the nature and origin of Mars surface rocks. We have investigated the following questions: (1) are the Pathfinder rocks igneous and is it possible these rocks could have formed by known igneous processes, such as equilibrium or fractional crystallization, operating within SNC magmas known to exist on Mars? If it is possible, what P (depth) and PH2O conditions are required? (2) whether TES-based interpretations of plagioclase-rich basalt and andesitic terrains in the south and north regions of Mars respectively are unique. Are the surface compositions of these regions plagioclase-rich, possibly indicating the presence of old AI-rich crust of Mars, or are the spectra being affected by something like surface weathering processes that might determine the spectral pyroxene to plagioclase ratio?

  12. Salt-Induced Physical Weathering of Stone

    NASA Astrophysics Data System (ADS)

    Schiro, M.; Ruiz-Agudo, E.; Rodriguez-Navarro, C.

    2010-12-01

    Salt weathering is recognized as an important mechanism that contributes to the modeling and shaping of the earth’s surface, in a range of environments spanning from the Sahara desert to Antarctica. It also contributes to the degradation and loss of cultural heritage, particularly carved stone and historic buildings. Soluble salts have recently been suggested to contribute to the shaping of rock outcrops on Mars and are being identified in other planetary bodies such as the moons of Jupiter (Europa and IO)1. Soluble salts such as sulfates, nitrates, chlorides and carbonates of alkali and alkali earth metals can crystallize within the porous system of rocks and building stones, exerting sufficient pressure against the pore walls to fracture the substrate. This physical damage results in increased porosity, thus providing a higher surface area for salt-enhanced chemical weathering. To better understand how salt-induced physical weathering occurs, we have studied the crystallization of the particularly damaging salt, sodium sulfate2, in a model system (a sintered porous glass of controlled porosity and pore size). For this elusive task of studying sub-surface crystallization in pores, we combined a variety of instruments to identify which phases crystallized during evaporation and calculated the supersaturation and associated crystallization pressure that caused damage. The heat of crystallization was measured using differential scanning calorimetry (DSC), providing the timing of crystallization events and phase transitions3, while the evaporation rate was recorded using thermal gravimetry (TG). These methods enabled calculation of the sodium sulfate concentration in solution at every point during evaporation. Two-dimensional X-ray diffraction (2D-XRD) performs synchrotron-like experiments in a normal lab by using a Molybdenum X-ray source (more than 5 times more penetrative than conventional Copper source). Using this method, we determined that the first phase to

  13. Geophysical and Chemical Weathering Signatures Across the Deep Weathered-Unweathered Granite Boundary of the Calhoun Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Richter, D., Jr.; Bacon, A. R.; Brantley, S. L.; Holbrook, W. S.

    2015-12-01

    To understand the relationship between geophysical measurements and chemical weathering at Earth's surface, we combine comprehensive chemical and physical analyses of a 70-m granite weathering profile in the Southern Piedmont in the southeastern United States. The research site is in the uplands of the Calhoun Critical Zone Observatory and is similar to many geomorphically stable, ancient, and highly-weathered Ultisol soils of the region. Surface and downhole geophysical analyses suggest significant physical changes to depths of about 40 m, where geophysical properties are consistent with competent and unweathered granite. At this depth, surface refraction velocities increase to >4.5 km/s; variations in downhole sonic velocities decrease by more than two-fold; and deviations in the downhole caliper log sharply decrease as well. Forty meters depth is also the depth of initiation of plagioclase feldspar weathering, as inferred from bulk geochemical measurement of the full 70-m deep core. Specifically, element-depth profiles, cast as mass transfer coefficient profiles using Ti and Zr as immobile elements, document inferred loss of plagioclase in the depth interval between 15 and 40-m depth. Plagioclase feldspar is the most abundant of the highly reactive minerals in the granite. Such a wide reaction front is characteristic of weathering granites. Some loss of K is observed at these depths but most K loss, as well as Mg loss, occurs at shallower depths. Nearby geophysical profiles and 3D stress models have been interpreted as showing that seismic velocities decrease at 40 m depth due to opening of fractures as rock is exhumed toward the surface. Given our interpretations of both the geochemical and geophysical data, we infer that the onset of chemical weathering of feldspar coincides with the opening of these fractures. The data highlight the ability of geochemistry and geophysics to complement each other and enrich our understanding of Earth's Critical Zone.

  14. Geochemistry and origin of ferruginous nodules in weathered granodioritic gneisses, Mysore Plateau, Southern India

    NASA Astrophysics Data System (ADS)

    Tripathi, Jayant K.; Rajamani, V.

    2007-04-01

    Fe-nodules occur within saprolites formed from weathering of granodioritic gneisses in the rain-shadow region of the Mysore Plateau adjacent to the Sahyadri Mountains in Southern India. These nodules and their host saprolites were studied for their geochemistry, including chemical speciation, to understand nodule formation and chemical redistribution processes during rock weathering. From their mode of occurrence, and mineralogical and geochemical data, we infer that the nodules originated by a two-stage process in which the initial extensive weathering of gneisses likely facilitated subsequent ferrolysis weathering and nodule formation. Nodules originated by precipitation of goethite, hematite and gibbsite along with several amorphous phases within the matrix of weathered gneisses. This is possible only under hydromorphic conditions, suggesting that parts of the plateau must have gone through a humid phase prior to the present aridity. In the saprolites, Al, Fe, and Ti become enriched because of the removal of Si, Ca, Na, and K. However within the nodule, Fe, Ti, Cr, and Ni are deposited after their chemical transport from the saprolite. Titanium, known for its immobile nature, was also mobilized and concentrated under the conditions of nodule formation. The most important elements in the nodule constitution are Fe, Al, Ti, and Mn, each having both crystalline and amorphous phases. Fe-Ti and Mn oxyhydroxides grain coatings in the saprolites and discrete amorphous Mn and Ti phases in the nodules seem to have scavenged trace elements from the weathering profile. REE were mobilized during weathering and nodule genesis in which Ce and Ti show a strong geochemical coherence. The enrichment of only HREE in saprolite, and both HREE and LREE with significant Ce in the nodule, indicate the control of evolving secondary minerals in the REE redistribution during rock weathering. Strong enrichment of Ce in the weathering profile and in nodules has important implications to

  15. Clay-mineraloid weathering products in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Gooding, James L.

    1986-01-01

    The production of clay mineraloids (CMs) in the weathering of stony meteorites recovered in the Allan Hills and Elephant Moraine areas of Antarctica is investigated, applying electron microbeam analysis, pyrolysis/mass spectroscopy, X-ray diffractometry, and differential scanning calorimetry to whole-rock chips from two eucrites, two diogenites, and an H5 chondrite. The data are presented in tables, graphs, and photomicrographs and characterized in detail. Massive to incipient-vermicular CM formations with smectitelike or micalike compositions and indications of poor crystallization are observed and attributed to hydrocryogenic diagenesis (with little or no liquid water) on time scales of 10-1000 kyr. The need to take the compositional effects of weathering into account before attempting to reconstruct the preterrestrial histories of meteorites is stressed.

  16. Mars weathering analogs - Secondary mineralization in Antarctic basalts

    NASA Technical Reports Server (NTRS)

    Berkley, J. L.

    1982-01-01

    Alkalic basalt samples from Ross Island, Antarctica, are evaluated as terrestrial analogs to weathered surface materials on Mars. Secondary alteration in the rocks is limited to pneumatolytic oxidation of igneous minerals and glass, rare groundmass clay and zeolite mineralization, and hydrothermal minerals coating fractures and vesicle surfaces. Hydrothermal mineral assemblages consist mainly of K-feldspar, zeolites (phillipsite and chabazite), calcite, and anhydrite. Low alteration rates are attributed to cold and dry environmental factors common to both Antarctica and Mars. It is noted that mechanical weathering (aeolian abrasion) of Martian equivalents to present Antarctic basalts would yield minor hydrothermal minerals and local surface fines composed of primary igneous minerals and glass but would produce few hydrous products, such as palagonite, clay or micas. It is thought that leaching of hydrothermal vein minerals by migrating fluids and redeposition in duricrust deposits may represent an alternate process for incorporating secondary minerals of volcanic origin into Martian surface fines.

  17. Summary of Rock-Property Measurements for Hong Kong TuffSamples

    SciTech Connect

    Dobson, Patrick F.; Nakagawa, Seiji

    2005-09-21

    A series of rock-property measurements was performed on a suite of rhyolitic tuff samples from the area above the Aberdeen Tunnel of Hong Kong. The goal of this study was to determine the mechanical properties of these samples after weathering. This report contains petrographic descriptions, porosity, bulk and grain density, as well as ultrasonic measurements, elastic modulii calculations, and rock-strength determinations. Variations in rock properties are related to alteration and the presence of fractures in the tuff. Granitic rocks located adjacent to the altered tuffs would be better candidates for underground excavations.

  18. SPADE: A Rock Crushing and Sample Handling System Developed for Mars Missions

    NASA Technical Reports Server (NTRS)

    Hansen, Candice J.; Paige, David A.

    2003-01-01

    Access to the interior of rocks on Mars is an important goal for understanding Mars petrology and geologic history. The spectral signature of the potentially diverse mineralogy of rocks on Mars is veiled by the ubiquitous dust and may be further hidden by weathered rind. We have developed a rock crusher and sample distribution system under the auspices of NASA s PIDDP program. We call it the SPADE : the Sample Processing and Distribution Experiment. Its purpose is to access the interiors of rocks on Mars and prepare samples for analysis by a suite of in situ instruments.

  19. Weathering processes and pickeringite formation in a sulfidic schist: a consideration in acid precipitation neutralization studies

    SciTech Connect

    Parnell, R.A. Jr.

    1983-01-01

    Extremely low abrasion pH values (2.8-3.3) characterize the weathering products of the Partridge Formation, a Middle-Ordovician metamorphosed, black, sulfidic shale. The local occurrence is observed of two sulfates that are rare in the Northeast: pickeringite and jarosite. X-ray diffraction studies of the weathering residues and the sulfate efflorescences have also identified dioctahedral and trioctahedral illite, kaolinite, vermiculite, and an 11-12 Angstrom phase, thought to be a type of randomly-interstratified biotite-vermiculite. From the mineralogical studies, qualitative weathering processes for the schist are formulated. A probable mechanism for the intense chemical weathering of the schist appears to be oxidation of iron sulfides to form iron oxide-hydroxides, sulfates, and sulfuric acid. This natural weathering process is proposed as an analog to anthropogenic low pH rock weathering resulting from acid precipitation. In the Northeast, natural weathering rates, may, in places, significantly affect the water chemistry and mineralogy used to quantify total (natural plus anthropogenic) weathering and leaching rates. 27 references, 4 figures.

  20. Seafloor weathering controls on atmospheric CO{sub 2} and global climate

    SciTech Connect

    Brady, P.V.; Gislason, S.R.

    1997-03-01

    Alteration of surficial marine basalts at low temperatures (<40{degrees}C) is a potentially important sink for atmospheric CO{sub 2} over geologic time. Petrologic analyses, thermodynamic calculations, and experimental weathering results point to extensive Ca leaching and consumption of marine CO{sub 2} during alteration. Basalt weathering in seawater-like solutions is sensitive to temperature. The activation energy for initial basalt weathering in seawater is 41-65 U kJ mol{sup -1}. If seafloor weathering temperatures are set by deep ocean fluids under high fluid to rock ratios the feedback between weathering and atmospheric CO{sub 2} is indirect, but sizeable. If the bulk of seafloor weathering occurs in the presence of low-temperature hydrothermal fluids, the weathering feedback depends on the linkage between spreading rates and heat flow. In either case, the primary linkage between seafloor weathering and the global carbon cycle appears to be thermal as opposed to chemical. 81 refs., 4 figs., 2 tabs.

  1. The Effects of Space Weathering at UV Wavelengths: S-Class Asteroids

    NASA Technical Reports Server (NTRS)

    Hendrix, Amanda R.; Vilas, Faith

    2006-01-01

    We present evidence that space weathering manifests itself at near-UV wavelengths as a bluing of the spectrum, in contrast with the spectral reddening that has been seen at visible-near-IR wavelengths. Furthermore, the effects of space weathering at UV wavelengths tend to appear with less weathering than do the longer wavelength effects, suggesting that the UV wavelength range is a more sensitive indicator of weathering, and thus age. We report results from analysis of existing near-UV (approx.220-350 nm) measurements of S-type asteroids from the International Ultraviolet Explorer and the Hubble Space Telescope and comparisons with laboratory measurements of meteorites to support this hypothesis. Composite spectra of S asteroids are produced by combining UV spacecraft data with ground-based longer wavelength data. At visible-near-IR wavelengths, S-type asteroids are generally spectrally redder (and darker) than ordinary chondrite meteorites, whereas the opposite is generally true at near-UV wavelengths. Similarly, laboratory measurements of lunar samples show that lunar soils (presumably more weathered) are spectrally redder at longer wavelengths, and spectrally bluer at near-UV wavelengths, than less weathered crushed lunar rocks. The UV spectral bluing may be a result of the addition of nanophase iron to the regolith through the weathering process. The UV bluing is most prominent in the 300-400 nm range, where the strong UV absorption edge is degraded with weathering.

  2. Mechanical changes in thawing permafrost rocks and their influence on rock stability at the Zugspitze summit, Germany - a research concept

    NASA Astrophysics Data System (ADS)

    Mamot, Philipp; Scandroglio, Riccardo; Krautblatter, Michael

    2015-04-01

    strength tests as well as P-wave velocity measurements of dozens of frozen and unfrozen Zugspitze limestone samples. Our future tasks are as follows: i) To assess the spatial permafrost distribution in the slope we plan to conduct further laboratory-calibrated ERT and SRT. A dense rock temperature measuring network as well as nearby weather stations will supply input data for a simple thermal model of the rock slope. ii) To assess the spatial and temporal pattern of rock instability at the test site we will continue measuring discontinuity movements. iii) Undertaking rock-mechanical laboratory tests on Zugspitze limestone and to focus on temperature related changes of friction along rock discontinuities without ice infill and fracture toughness KIIc of intact rock bridges. These tests will be carried out with a direct shear box in unfrozen and frozen state. The measurement of P-wave velocity of the same rock samples will help to upscale rock toughness values to the rock slope at the study site. We aim at developing and calibrating a discontinuum mechanical model of stability changes in thawing permafrost rocks. Krautblatter, M., Funk, D., Günzel, F. K. (2013): Why permafrost rocks become unstable: a rock-ice-mechanical model in time and space. Earth Surface Processes and Landforms 38, 876-887.

  3. Non-systematic weathering profile in the Blue Ridge Mountains, N. C. : Role of geochemical variables

    SciTech Connect

    Ciampone, M.A.; McVey, D.E.; Gerke, T.L.; Briggs, W.D.; Zhang, Yangsheng; Maynard, J.B.; Huff, W.D. . Dept. of Geology)

    1992-01-01

    Weathering profiles from representative cores of the Coweeta Group, schist, and Tallulah Falls Fm, gneiss, in the Blue Ridge Mountains of North Carolina were examined. The predominant alteration minerals, which formed from the partial alteration of biotite and plagioclase, include kaolinite, chlorite, vermiculite interstratified with biotite, gibbsite. These mineral phases were identified using petrographic observation, SEM, X-ray diffraction, and selected electron microprobe analysis. These minerals commonly represent a weathering profile (developed from surface to depth on a single source rock) ranging from mature (gibbsite), to intermediate (kaolinite + interlayered biotite/vermiculite), to immature (plagioclase + biotite) at depth. In this study, however, there is no clear vertical zonation of the weathering profile. This indicates a more selective weathering process than would typically be assumed. This nonsystematic weathering profile may reflect variations in bulk composition of the parent rock and/or variations in the composition of ground water. The presence and abundance of gibbsite in these weathering profiles is unusual because it is normally associated with bauxite in which the Al[sub 2]O[sub 3] content is > 80 wt.%. In this study the Al[sub 2]O[sub 3] content of the regolith is approximately 20 wt.%. The presence of gibbsite emphasizes the importance of solution-reprecipitation of Al-rich phases as an independent process in temperature climates, and suggests the activity of silica is more critical than regional climatological effects in controlling regolith formation.

  4. Enhanced weathering strategies for cooling the planet and saving coral reefs

    NASA Astrophysics Data System (ADS)

    Beerling, D. J.; Taylor, L.; Quirk, J.; Thorley, R.; Kharecha, P. A.; Hansen, J. E.; Ridgwell, A. J.; Lomas, M.; Banwart, S. A.

    2014-12-01

    Acceleration of the chemical weathering sink for atmospheric CO2 via distribution of pulverized silicate rocks across terrestrial landscapes has been proposed as a macro-engineering Carbon Dioxide Removal (CDR) scheme, but its effectiveness and response to ongoing global change is poorly understood. We employ a detailed spatially resolved weathering model driven by two ensemble Representative Concentration Pathway (RCP) projections of 21st Century climate (RCP8.5 and RCP4.5) to assess enhanced weathering and examine feedbacks on atmospheric CO2 and ocean carbonate biogeochemistry. Atmospheric CO2 reduction of ~100-260 ppm by year 2100, the range depending mainly on rock composition, is obtained by spreading 5 kg m-2 yr-1 over 20 Mkm2 tropical weathering 'hotspots'. Ocean acidification is neutralized in RCP4.5 and ameliorated in RCP8.5 due to enhanced land-ocean export of weathered alkalinity products and reduced CO2 forcings, and the aragonite saturation state of surface oceans is raised to >3.5, thus avoiding likely extinction of coral reef ecosystems. We suggest that accelerated weathering has substantial potential to help limit global warming and benefits to marine life not obtained from other CDR approaches, but major issues of cost, social acceptability, and potential unanticipated consequences should encourage urgent efforts to phase down fossil fuel emissions.

  5. A new approach to the selection of materials for engineered barriers and appropriate host rocks for high level waste disposal

    SciTech Connect

    Omelianenko, B.I.; Nikonov, B.S.; Ryzhov, B.I.; Shikina, N.D.; Yudintsev, S.V.

    1995-12-31

    Sorptive properties of weathered dunites, gabbro-diabases and basic volcanic rocks for Sr and Cs were studied. The results show that the sorptive capacities of these rocks are equivalent to or, in some cases, superior to the industrial sorptive materials. Results of a uranium distribution study by fission-track radiography suggest that material from weathered basic rocks is characterized by high sorptive properties for uranium also. One can assume that other radionuclides of the transuranic group will be intensely sorbed by the residuum of weathered basic rocks. Low-temperature hydrothermal transformation leads to sealing fissures of the basic rocks with highly sorptive minerals, for example, smectite, chlorite, serpentine, in talc, zeolite, hydroxides of Fe, Ti, Mn. The process results in contemporaneous decreasing hydraulic conductivity and increasing sorptive capacity of the rocks. HLW disposal at the radiochemical plant Mayak is expected to be produced in deep wells situated in basaltic rocks. The safety of disposal is based on high sorptive properties of the crust of weathering and protective capacities of volcanic rocks. This method is not expensive and may allow the disposal of HLW in the near future.

  6. Commercializing Space Weather using GAIM

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent; Schunk, Robert; Sojka, Jan J.

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the en-ergy transfer processes from the Sun's photons, particles, and fields. Of the space environment domains that are affected by space weather, the ionosphere is the key region that affects com-munication and navigation systems. The Utah State University (USU) Space Weather Center (SWC) was organized in 2009 to develop commercial space weather applications. It uses the Global Assimilation of Ionospheric Measurements (GAIM) system as the basis for providing improvements to communication and navigation systems. For example, in August 2009 SWC released, in conjunction with Space Environment Technologies, the world's first real-time space weather via an iPhone app, Space WX. It displays the real-time, current global ionosphere to-tal electron content along with its space weather drivers, is available through the Apple iTunes store, and is used around the world. The GAIM system is run operationally at SWC for global and regional (continental U.S.) conditions. Each run stream continuously ingests up to 10,000 slant TEC measurements every 15-minutes from approximately 500 stations in a Kalman filter to adjust the background output from the physics-based Ionosphere Forecast Model (IFM). Additionally, 80 real-time digisonde data streams from around the world provide ionosphere characterization up to the F-region peak. The combination of these data dramatically improves the current epoch ionosphere specification beyond the physics-based solution. The altitudinal range is 90-1500 km for output TEC, electron densities, and other data products with a few degrees resolution in latitude and longitude at 15-minute time granularity. We describe the existing SWC products that are used as commercial space weather information. SWC funding is provided by the State of Utah's Utah Science Technology and Research (USTAR) initiative. The SWC is physically located on the USU campus in Logan, Utah.

  7. Integration of Weather Avoidance and Traffic Separation

    NASA Technical Reports Server (NTRS)

    Consiglio, Maria C.; Chamberlain, James P.; Wilson, Sara R.

    2011-01-01

    This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

  8. Acid Sulfate Weathering on Mars: Results from the Mars Exploration Rover Mission

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.; Morris, R. V.; Golden, D. C.

    2006-01-01

    Sulfur has played a major role in the formation and alteration of outcrops, rocks, and soils at the Mars Exploration Rover landing sites on Meridiani Planum and in Gusev crater. Jarosite, hematite, and evaporite sulfates (e.g., Mg and Ca sulfates) occur along with siliciclastic sediments in outcrops at Meridiani Planum. The occurrence of jarosite is a strong indicator for an acid sulfate weathering environment at Meridiani Planum. Some outcrops and rocks in the Columbia Hills in Gusev crater appear to be extensively altered as suggested by their relative softness as compared to crater floor basalts, high Fe(3+)/FeT, iron mineralogy dominated by nanophase Fe(3+) oxides, hematite and/or goethite, corundum-normative mineralogies, and the presence of Mg- and Casulfates. One scenario for aqueous alteration of these rocks and outcrops is that vapors and/or fluids rich in SO2 (volcanic source) and water interacted with rocks that were basaltic in bulk composition. Ferric-, Mg-, and Ca-sulfates, phosphates, and amorphous Si occur in several high albedo soils disturbed by the rover's wheels in the Columbia Hills. The mineralogy of these materials suggests the movement of liquid water within the host material and the subsequent evaporation of solutions rich in Fe, Mg, Ca, S, P, and Si. The presence of ferric sulfates suggests that these phases precipitated from highly oxidized, low-pH solutions. Several hypotheses that invoke acid sulfate weathering environments have been suggested for the aqueous formation of sulfate-bearing phases on the surface of Mars including (1) the oxidative weathering of ultramafic igneous rocks containing sulfides; (2) sulfuric acid weathering of basaltic materials by solutions enriched by volcanic gases (e.g., SO2); and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials.

  9. Our World: The Rock Cycle

    NASA Video Gallery

    Find out how rocks brought to Earth by the Apollo astronauts have helped NASA learn more about the rock cycle. Compare igneous, sedimentary and metamorphic rocks found on Earth to three types of ro...

  10. Sampling the oxidative weathering products and the potentially acidic permafrost on Mars

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.

    1988-01-01

    Large areas of Mars' surface are covered by oxidative weathering products containing ferric and sulfate ions having analogies to terrestrial gossans derived from sulfide mineralization associated with iron-rich basalts. Chemical weathering of such massive and disseminated pyrrhotite-pentlandite assemblages and host basaltic rocks in the Martian environment could have produced metastable gossaniferous phases (limonite containing poorly crystalline hydrated ferric sulfates and oxyhydroxides, clay silicates and opal). Underlying groundwater, now permafrost on Mars, may still be acidic due to incomplete buffering reactions by wall-rock alteration of unfractured host rock. Such acidic solutions stabilize temperature-sensitive complex ions and sols which flocculate to colloidal precipitates at elevated temperatures. Sampling procedures of Martian regolith will need to be designed bearing in mind that the frozen permafrost may be corrosive and be stabilizing unique complex ions and sols of Fe, Al, Mg, Ni and other minor elements.

  11. Naturally occurring radionuclides and rare earth elements in weathered Japanese soil samples

    NASA Astrophysics Data System (ADS)

    Sahoo, Sarata; Hosoda, Masahiro; Prasad, Ganesh; Takahashi, Hiroyuki; Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Tokonami, Shinji; Uchida, Shigeo

    2013-08-01

    The activity concentrations of 226Ra and 228Ac in weathered Japanese soils from two selected prefectures have been measured using a γ-ray spectroscopy system with high purity germanium detector. The uranium, thorium, and rare earth elements (REEs) concentrations were determined from the same soil samples using inductively coupled plasma mass spectrometry (ICP-MS). For example, granitic rocks contain higher amounts of U, Th, and light REEs compared to other igneous rocks such as basalt and andesites. Therefore, it is necessary to understand the interaction between REEs and nature of soils since soils are complex heterogeneous mixture of organic and inorganic solids, water, and gases. In this paper, we will discuss about distribution pattern of 238U and 232Th along with REEs in soil samples of weathered acid rock (granite) collected from two prefectures of Japan: Hiroshima and Miyagi.

  12. Evaluating the Contribution of Eolian Dust to the Weathering Flux From Mountain Soils

    NASA Astrophysics Data System (ADS)

    Lawrence, C. R.; Neff, J. C.; Farmer, G. L.

    2008-12-01

    The weathering of silicate minerals is an important control on the global carbon cycle over geologic timescales. In order to accurately characterize the influence of silicate weathering on the carbon cycle, it is important to quantify the mechanisms that may influence weathering. Tectonics, erosion, climate, and rock chemistry are all important factors in the weathering process. There is also evidence that eolian dust deposition may influence weathering fluxes in some settings. The transport of fine sediments from arid regions, with relatively slow rates of chemical weathering, to regions more favorable to weathering may act to accelerate global weathering rates. Detailed studies of dust deposition and soil evolution are required to better quantify the role that dust plays in the weathering process. The San Juan Mountains of southern Colorado are situated downwind from large dust producing regions of the Colorado Plateau and the Mojave Dessert. A recent study suggests the transport of dust from these semi-arid environments to the downwind mountain ecosystems has increased by 500% over the past century, likely as a result of human land-use changes. At present, the San Juan Mountains receive between 5-15 g/m2 of fine textured dust deposition each year. Over many years, dust accretion may have altered the geochemical characteristics of soils and could be an important factor for the chemical weathering flux from these soils. We combine soil geochemical mass balance calculations with quantitative mineralogy and strontium isotope measurements of sequential soil leaches to better constrain the input of dust to soils and to estimate the contribution of dust to the long- term chemical weathering flux.

  13. First look at rock & soil properties

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The earliest survey of spectral properties of the rocks and soils surrounding Pathfinder was acquired as a narrow strip covering the region just beyond the where the rover made its egress from the lander. The wavelength filters used, all in the binocular camera's right eye, cover mainly visible wavelengths. These data reveal at least five kinds of rocks and soil in the immediate vicinity of the lander. All of the spectra are ratioed to the mean spectrum of bright red drift to highlight the differences. Different occurrences of drift (pink spectra) are closely similar. Most of the rocks (black spectra) have a dark gray color, and are both darker and less red than the drift, suggesting less weathering. Typical soils (green spectra) are intermediate in properties to the rocks and drift. Both these data and subsequent higher resolution images show that the typical soil consists of a mixture of drift and small dark gray particles resembling the rock. However, two other kinds of materials are significantly different from the rocks and drift. Pinkish or whitish pebbles and crusts on some of the rocks (blue spectra) are brighter in blue light and darker in near-infrared light than is the drift, and they lack the spectral characteristics closely associated with iron minerals. Dark red soils in the lee of several rocks are about as red as the drift, but consistently darker. The curvature in the spectrum at visible wavelengths suggests either more ferric iron minerals than in the drift or a larger particle size.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division

  14. Clay mineralogy of weathering profiles from the Carolina Piedmont.

    USGS Publications Warehouse

    Loferski, P.J.

    1981-01-01

    Saprolite profiles (12) that formed over various crystalline rocks from the Charlotte 1o X 2o quadrangle showed overall similarity in their clay mineralogy to depths of 6 to 45 m indicating control by weathering processes rather than by rock type. Most saprolite contained 10-25% clay, and ranged 3 to 70%. Kaolinite and halloysite composed = or >75% of the clay fraction of most samples. The ratio kaolinite:halloysite ranged widely, from 95% kaolinite to 90% halloysite, independent of depth. Clay-size mica was present in all profiles, and ranged 5-75% over a sericite schist. Mixed-layer mica-smectite and mica-vermiculite were subordinate; discrete smectite and vermiculite were rare. The abundance of halloysite indicates a continuously humid environment since the time of profile formation, because of the rapidity with which halloysite dehydrates irreversibly. -R.S.M.

  15. Identifying the changes of geo-engineering properties of dunites due to weathering utilizing electrical resistivity tomography (ERT)

    NASA Astrophysics Data System (ADS)

    Ündül, Ömer; Tuğrul, Atiye; Özyalın, Şenol; Halil Zarif, İ.

    2015-04-01

    Weathering phenomena have an important role in many construction facilities with varying depths and grades. Due to the anisotropic and heterogeneous nature of weathering profiles of some rocks, uncertainities exist in determining the geo-engineering properties. Geo-electrical studies have been utilized to overcome such uncertainities for various subsurface conditions including the determination of boundaries between weathered and unweathered parts of different rock types. In this study, the electrical resistivity tomography (ERT) results were correlated with conventional methods in determining the effects of weathering on the geo-engineering properties of dunites. During the research, weathering grades were determined by field studies including discontinuity spacings, aperture and properties of fill materials. The detailed petrographical studies, determination of petrophysical properties (e.g. water absorption and effective porosity) and mechanical properties (e.g. unconfined compressive strength (UCS)) constitute the laboratory studies. ERT studies were carried out in a row of sixty electrodes with electrode spacings of 0.5 m utilizing a Wenner-Schlumberger configuration. According to the comparison of the inversion model sections with the weathering profiles obtained by field and laboratory studies it is concluded that the use of ERT with a Wenner-Schlumberger configuration supplies comparable data for wider subsurface areas from the view of weathering and its effect on geo-engineering properties of dunites. In addition, ERT techniques are very useful where conventional techniques are inadequate in determining the full weathering profile.

  16. Merging Space Weather With NOAA's National Weather Service

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Louis

    2004-07-01

    A major change in the reporting structure of the National Oceanic and Atmospheric Administration's Space Environment Center (SEC) is poised to occur later this year when Congress approves the fiscal year 2005 budget proposed by the Bush administration. The activities of the center, together with its proposed budget, will move from under NOAA's research budget and administration to that of the National Weather Service (NWS), which is also administered by NOAA. The weather service will receive augmented funding to accommodate the SEC as one of the service's National Centers for Environmental Prediction.

  17. Evolution of porosity and diffusivity associated with chemical weathering of a basalt clast

    SciTech Connect

    Navarre-Sitchler, A.; Steefel, C.I.; Yang, L.; Tomutsa, L.; Brantley, S.L.

    2009-02-15

    Weathering of rocks as a result of exposure to water and the atmosphere can cause significant changes in their chemistry and porosity. In low-porosity rocks, such as basalts, changes in porosity, resulting from chemical weathering, are likely to modify the rock's effective diffusivity and permeability, affecting the rate of solute transport and thus potentially the rate of overall weathering to the extent that transport is the rate limiting step. Changes in total porosity as a result of mineral dissolution and precipitation have typically been used to calculate effective diffusion coefficients through Archie's law for reactive transport simulations of chemical weathering, but this approach fails to account for unconnected porosity that does not contribute to transport. In this study, we combine synchrotron X-ray microcomputed tomography ({mu}CT) and laboratory and numerical diffusion experiments to examine changes in both total and effective porosity and effective diffusion coefficients across a weathering interface in a weathered basalt clast from Costa Rica. The {mu}CT data indicate that below a critical value of {approx}9%, the porosity is largely unconnected in the basalt clast. The {mu}CT data were further used to construct a numerical pore network model to determine upscaled, effective diffusivities as a function of total porosity (ranging from 3 to 30%) for comparison with diffusivities determined in laboratory tracer experiments. By using effective porosity as the scaling parameter and accounting for critical porosity, a model is developed that accurately predicts continuum-scale effective diffusivities across the weathering interface of the basalt clast.

  18. Mapping Glacial Weathering Processes with Thermal Infrared Remote Sensing: A Case Study at Robertson Glacier, Canada

    NASA Astrophysics Data System (ADS)

    Rutledge, A. M.; Christensen, P. R.; Shock, E.; Canovas, P. A., III

    2014-12-01

    Geologic weathering processes in cold environments, especially subglacial chemical processes acting on rock and sediment, are not well characterized due to the difficulty of accessing these environments. Glacial weathering of geologic materials contributes to the solute flux in meltwater and provides a potential source of energy to chemotrophic microbes, and is thus an important component to understand. In this study, we use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data to map the extent of glacial weathering in the front range of the Canadian Rockies using remotely detected infrared spectra. We ground-truth our observations using laboratory infrared spectroscopy, x-ray diffraction, and geochemical analyses of field samples. The major goals of the project are to quantify weathering inputs to the glacial energy budget, and to link in situ sampling with remote sensing capabilities. Robertson Glacier, Alberta, Canada is an excellent field site for this technique as it is easily accessible and its retreating stage allows sampling of fresh subglacial and englacial sediments. Infrared imagery of the region was collected with the ASTER satellite instrument. At that same time, samples of glacially altered rock and sediments were collected on a downstream transect of the glacier and outwash plain. Infrared laboratory spectroscopy and x-ray diffraction were used to determine the composition and abundance of minerals present. Geochemical data were also collected at each location, and ice and water samples were analyzed for major and minor elements. Our initial conclusion is that the majority of the weathering seems to be occurring at the glacier-rock interface rather than in the outwash stream. Results from both laboratory and ASTER data indicate the presence of leached weathering rinds. A general trend of decreasing carbonate abundances with elevation (i.e. residence time in ice) is observed, which is consistent with increasing calcium ion

  19. Dirty Rotten Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image taken by the panoramic camera on the Mars Exploration Rover Spirit shows a collection of rocks (upper right) at Gusev Crater that have captured the attention of scientists for their resemblance to rotting loaves of bread. The insides of the rocks appear to have been eroded, while their outer rinds remain more intact. These outer rinds are reminiscent of those found on rocks at Meridiani Planum's 'Eagle Crater.' This image was captured on sol 158 (June 13, 2004).

  20. Rock Garden Mosaic

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image mosaic of part of the 'Rock Garden' was taken by the Sojourner rover's left front camera on Sol 71 (September 14). The rock 'Shark' is at left center and 'Half Dome' is at right. Fine-scale textures on the rocks are clearly seen. Broken crust-like material is visible at bottom center.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  1. Weird 'Endurance' Rock Ahead

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken by the Mars Exploration Rover Opportunity shows a bizarre, lumpy rock dubbed 'Wopmay' on the inner slopes of 'Endurance Crater.' Scientists say the rock's unusual texture is unlike any others observed so far at Meridiani Planum. Wopmay measures approximately 1 meter (3.3 feet) across. The image was taken by the rover's panoramic camera on sol 195 (Aug. 11, 2004). Opportunity will likely travel to this or a similar rock in coming sols for a closer look at the alien surface.

  2. Detached rock evaluation device

    DOEpatents

    Hanson, David R.

    1986-01-01

    A rock detachment evaluation device (10) having an energy transducer unit 1) for sensing vibrations imparted to a subject rock (172) for converting the sensed vibrations into electrical signals, a low band pass filter unit (12) for receiving the electrical signal and transmitting only a low frequency segment thereof, a high band pass filter unit (13) for receiving the electrical signals and for transmitting only a high frequency segment thereof, a comparison unit (14) for receiving the low frequency and high frequency signals and for determining the difference in power between the signals, and a display unit (16) for displaying indicia of the difference, which provides a quantitative measure of rock detachment.

  3. Weather types and traffic accidents.

    PubMed

    Klaić, Z B

    2001-06-01

    Traffic accident data for the Zagreb area for the 1981-1982 period were analyzed to investigate possible relationships between the daily number of accidents and the weather conditions that occurred for the 5 consecutive days, starting two days before the particular day. In the statistical analysis of low accident days weather type classification developed by Poje was used. For the high accident days a detailed analyses of surface and radiosonde data were performed in order to identify possible front passages. A test for independence by contingency table confirmed that conditional probability of the day with small number of accidents is the highest, provided that one day after it "N" or "NW" weather types occur, while it is the smallest for "N1" and "Bc" types. For the remaining 4 days of the examined periods dependence was not statistically confirmed. However, northern ("N", "NE" and "NW") and anticyclonic ("Vc", "V4", "V3", "V2" and "mv") weather types predominated during 5-days intervals related to the days with small number of accidents. On the contrary, the weather types with cyclonic characteristics ("N1", "N2", "N3", "Bc", "Dol1" and "Dol"), that are generally accompanied by fronts, were the rarest. For 85% days with large number of accidents, which had not been caused by objective circumstances (such as poor visibility, damaged or slippery road etc.), at least one front passage was recorded during the 3-days period, starting one day before the day with large number of accidents. PMID:11787547

  4. Space Weather - the Economic Case

    NASA Astrophysics Data System (ADS)

    Bisi, M. M.; Gibbs, M.

    2015-12-01

    Following on from the UK Government's placement of space weather on it's National Risk Register, in 2011, and the Royal Academy of Engineering's study into the impacts of a severe space weather event, the next piece of key evidence, to underpin future investment decisions, is understanding the socio-economic impact of space weather This poster outlines a study, funded by the UK Space Agency, which will assess the socio-economic cost of space weather, both severe events, such as 1989 & a modern day repeat of the Carrington storm and also the cost of day-to-day impacts. The study will go on to estimate the cost benefit of forecasting and also investigate options for an operational L5 spacecraft mission and knowledge exchange activities with the South African Space Agency. The findings from the initial space weather socio-economic literature review will be presented along with other findings to date and sets out the tasks for the remainder of this programme of work.

  5. New estimates of silicate weathering rates and their uncertainties in global rivers

    NASA Astrophysics Data System (ADS)

    Moon, Seulgi; Chamberlain, C. P.; Hilley, G. E.

    2014-06-01

    This study estimated the catchment- and global-scale weathering rates of silicate rocks from global rivers using global compilation datasets from the GEMS/Water and HYBAM. These datasets include both time-series of chemical concentrations of major elements and synchronous discharge. Using these datasets, we first examined the sources of uncertainties in catchment and global silicate weathering rates. Then, we proposed future sampling strategies and geochemical analyses to estimate accurate silicate weathering rates in global rivers and to reduce uncertainties in their estimates. For catchment silicate weathering rates, we considered uncertainties due to sampling frequency and variability in river discharge, concentration, and attribution of weathering to different chemical sources. Our results showed that uncertainties in catchment-scale silicate weathering rates were due mostly to the variations in discharge and cation fractions from silicate substrates. To calculate unbiased silicate weathering rates accounting for the variations from discharge and concentrations, we suggest that at least 10 and preferably ∼40 temporal chemical data points with synchronous discharge from each river are necessary. For the global silicate weathering rate, we examined uncertainties from infrequent sampling within an individual river, the extrapolation from limited rivers to a global flux, and the inverse model selections for source differentiation. For this weathering rate, we found that the main uncertainty came from the extrapolation to the global flux and the model configurations of source differentiation methods. This suggests that to reduce the uncertainties in the global silicate weathering rates, coverage of synchronous datasets of river chemistry and discharge to rivers from tectonically active regions and volcanic provinces must be extended, and catchment-specific silicate end-members for those rivers must be characterized. With current available synchronous datasets, we

  6. Reply to the comments on [open quotes]Weathering, plants, and the long-term carbon cycle[close quotes

    SciTech Connect

    Cochran, M.F.; Berner, R.A. )

    1993-05-01

    Some lichens can and do promote the weathering of their substrates. The authors' sole interest for purposes of carbon-cycle modeling is the degree of that enhancement for calcium and magnesium silicates relative to both abiotic chemical weathering due to water-rock interaction and the weathering that occurs beneath higher plants. The work by Jackson and Keller (1970) had offered the most dramatic quantitative, empirical evidence for weathering-rate enhancement by a primitive terrestrial organism; thus, reassessment of their conclusions is of considerable importance. In analyzing their samples, the authors used the technique of back-scattered electron imaging. Their results showed that the ferrihydrite-rich gels created by Stereocaulon vulcani were formed from wind-supplied dust, volcanic ash, and detrital rock fragments, not the lichen's immediate substrate.

  7. Blasting and excavating on precarious rock slopes

    SciTech Connect

    Oriard, L.L.

    1996-12-01

    There is an intuitive tendency to equate rock strength with rock stability, yet the two must be evaluated separately. A slope in strong hard rock is not necessarily stable, nor is a slope in weathered weak rock necessarily unstable. In some cases the reverse is true, depending on the geometry of joints and weak planes. The time element is a matter of special concern, that is how suddenly the failure begins and how rapidly it progresses. An important element in avoiding catastrophes is to study the site geology for dangerous conditions, implement the types of blasting procedures that minimize failures, and evaluate the potential use of reinforcement or other mechanical stabilizing procedures. It may be possible to reinforce the perimeters of structural excavations, but that is not usually possible for quarry or surface mine operations. However, it is often possible to change a dangerous operation into a safe one merely by changing the orientation, sequence or dimensions of the work without changing other details of the blasting designs. Several important principles are illustrated in this paper, using case histories. One case is that of a catastrophic slope failure in Mexico, and the remedial procedures used to get the work back into operation. That case is compared to large-scale work which was done safely on a similar site in Spain, even with an 850 ft high slope and up to 200 ft between safety benches. Also illustrated are some of the procedures used for delicate work on sensitive slopes at a site in Colombia, South America, and those used to preserve a delicate narrow rib of rock in a deep river canyon on the Snake River in Idaho. Brief reference is made also to slope damage on a Canadian project.

  8. Effects of weathering and lithology on the quality of aggregates in the alluvial fans of Northeast Rivand, Sabzevar, Iran

    NASA Astrophysics Data System (ADS)

    Bahrami, Shahram; Fatemi Aghda, Seyed Mahmoud; Bahrami, Kazem; Motamedi Rad, Mohammad; Poorhashemi, Sima

    2015-07-01

    Alluvial fans as depositional landforms can be considered as potential sources of aggregates. As the age of alluvial fans increases, their constituent sediments are exposed to longer periods of weathering and increased mineral alteration, resulting in a decrease in aggregate quality. In this study, physical properties and point load tests were used to assess the aggregate quality on three alluvial fan surfaces (relict, old and young) in the northeastern part of Rivand village in west of Sabzevar, Northeast Iran. Differentiating young from old and relict fans was carried out based on geomorphic criteria such as weathering features, fan surface morphology and drainage pattern. The young alluvial fan is characterized by sub-rounded and unvarnished clasts, distributary drainage patterns and a relatively flat surface, whereas old and relict fans are characterized by incised and rough surfaces, tributary drainage pattern and highly weathered and varnished clasts due to their long-term exposure to weathering. Due to a range of rock types occurring across each fan surface, lithological studies were performed to eliminate the effect of lithology on aggregate quality. A total of 18 rock types comprising comparable lithologies were sampled from each of the three alluvial fans. Results show that, in almost all 18 rock types, the point load test values increases from relict to young fans whereas porosity and percentage of water absorption decrease, implying that aggregate quality decreases with time as a function of duration of exposure to weathering. Also, the strength of aggregates in all three fans decreases from the fan apex to the fan toe. Data show that micaceous, intrusive igneous rocks, tuffs with high porosity and fine-grained extrusive igneous rocks with some porosity are more sensitive to physical weathering, and therefore have lower strength, particularly on the relict and old fans. Overall, variations in aggregate strength on these fans can be attributed to the

  9. Mineralogical Characteristics of Carbonate Rock-Hosted Naturally Occurring Asbestos

    NASA Astrophysics Data System (ADS)

    Shin, E.; Roh, Y.

    2012-12-01

    Naturally Occurring Asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. The parent rocks of asbestos have been associated with ultramafic and mafic rocks, and carbonate rock. The previous studies on naturally occurring asbestos were mainly limited to ultramafic and mafic rock-hosted asbestos and studies on carbonate rock-hosted asbestos are relatively rare in South Korea. Therefore, this study was aimed to characterize mineralogy of carbonate rock-hosted NOA at Muju and Jangsu, Jeonbuk province and Seosan and Asan, Chungnam province. The rock types at the four sites are consisting mainly of Precambrian metasedimentary rock. XRD and PLM analyses showed fibrous minerals in the sites were tremolite and actinolite of acicular and columnar forms. SEM-EDS analyses showed that asbestiform tremolite and actinolite had various ratios of length and diameters over 12:1, and needle and columnar forms. A columnar forms of tremolite and actinolite were showed small acicular at the edge of the particle. Its main chemical compositions are mainly Si, O, Mg, Ca, which were identical to tremolite. Actinolite contains Fe in addition to Si, O, Mg, Ca. EPMA analyses of asbestos occurred at Muju indicated that chemical composition are 55% SiO2, 23.2% MgO, 13.1 % CaO, and 0.61 % FeO and the chemical formula calculated as (K0.01Na0.01)Ca2.01(Mg4.94Fe0.05) (Al0.004Si7.98)O22(OH)2, which is close to ideal tremolite. In addition to tremolite, actinolite was also occurred at Seosan, Chungnam. XRD analyses showed that antigorite was existed at Muju, but PLM and SEM analyses showed the antigorite was platy structure, not asbestiform. These results indicate that asbestiform tremolite and actinolite with acicular forms contains in carbonate rocks at Muju and Jangsu, Jeonbuk and Seosan and Asan, Chungnam province South Korea.

  10. Interplanetary Disturbances Affecting Space Weather

    NASA Astrophysics Data System (ADS)

    Wimmer-Schweingruber, Robert F.

    2014-01-01

    The Sun somehow accelerates the solar wind, an incessant stream of plasma originating in coronal holes and some, as yet unidentified, regions. Occasionally, coronal, and possibly sub-photospheric structures, conspire to energize a spectacular eruption from the Sun which we call a coronal mass ejection (CME). These can leave the Sun at very high speeds and travel through the interplanetary medium, resulting in a large-scale disturbance of the ambient background plasma. These interplanetary CMEs (ICMEs) can drive shocks which in turn accelerate particles, but also have a distinct intrinsic magnetic structure which is capable of disturbing the Earth's magnetic field and causing significant geomagnetic effects. They also affect other planets, so they can and do contribute to space weather throughout the heliosphere. This paper presents a historical review of early space weather studies, a modern-day example, and discusses space weather throughout the heliosphere.

  11. An Unusual Process of Accelerated Weathering of a Marly Limestone

    NASA Astrophysics Data System (ADS)

    Ercoli, L.; Rizzo, G.; Algozzini, G.

    2003-04-01

    This work deals with a singular case of stone deterioration, which occurred during the restoration of the Cathedral of Cefalù. In particular, a significant process of stone decohesion started after a consolidation treatment on ashlars of the external face of the cloister portico. A study was carried out to characterize the stone and to investigate the deterioration process. Petrographical, chemical and physical analyses were performed on samples taken from the wall. The results indicate that the medieval monument was built using a Pliocene marly limestone, called "trubo", quarried from outcrops of the environs of Cefalù. The rock is soft and uniformely cemented. The carbonatic fraction of the rock is due to foraminifera shells; the rock also contains detritic quartz, feldspate and glauconite. The clay minerals, mainly illite and montmorillonite, are widespread in the rock in the form of thin layers. The use of such a stone in a building of relevant artistic value is definitely unusual. In fact, the "trubo" is a rock subjected to natural decay because of its mineralogical composition and fabric; as effect of natural weathering, in the outcrops the rock disaggregates uniformely, producing silt. In the cloister this effect was magnified by extreme environmental conditions (marine spray, severe excursions of both relative humidity and temperature). Furthermore, after soluble salts removing and subsequent consolidation with ethyl silicate, a significant acceleration of the decay process was observed, producing friable scales detach for a depth of about 3 cm into the ashlars. The stone appeared corroded and uneven. Experimental tests were performed in laboratory in order to evidence any origin of incompatibility between such stone composition and the treatments carried out, which on the other hand are the most generally adopted in restoration interventions.

  12. Reaction-driven fracturing of porous rock

    NASA Astrophysics Data System (ADS)

    Ulven, O. I.; Jamtveit, B.; Malthe-Sørenssen, A.

    2014-10-01

    A 2-D computer model has been developed to investigate fluid-mediated transformation processes such as chemical weathering, mineral carbonation, and serpentinization that require transport of H2O and/or CO2 into reacting rock volumes. Hydration and carbonation cause local volume expansion, and the resulting nonuniform stresses may drive fracturing, which increases both the rate of transport and the accessible reactive surface area in the system and thus accelerates the rate of the transformation process. The model couples reactions, fracturing, and fluid transport for systems with a range of initial porosities, assumed constant throughout the process. With low initial porosity, a sharp reaction front between completely reacted material and unreacted material propagates into unaltered rock, while for high porosities, diffuse reaction fronts are formed in which a large fraction of the initial volume is partly reacted. When diffusive transport is rate limiting, the total reaction rate depends on porosity to a power N, where N is in the range 0.45-2. The exponent N increases as the reaction-generated expansion decreases. In high-porosity rocks, the total reaction rate is limited by reaction kinetics, and it is thus insensitive to porosity variations. As the volume increasing reaction proceeds, fracturing divides the unreacted porous material into subdomains, which may undergo further subdivision as they are consumed by the reaction. The total reaction rate and progress depend on the initial geometry of a reacting domain, and this significantly affects the weathering profiles for systems that evolve from an initial assembly of blocks with different sizes and shapes.

  13. Astrobiological implications of rock varnish in Tibet.

    PubMed

    Krinsley, David; Dorn, Ronald I; DiGregorio, Barry

    2009-01-01

    The study of terrestrial geomicrobiology and its relationship to rock weathering processes is an essential tool in developing analogues for similar processes that may have occurred on Mars. Most studies of manganese-enhanced rock varnish have focused on samples taken from warm arid desert regions. Here, we examine samples obtained from eolian-abraded lava flows of the 4700-4800 m high Ashikule Basin in Tibet. Because it receives approximately 300 mm of precipitation annually, this site is nowhere near as dry as Atacama Desert locales. However, the dusty, sulfate-rich, high-altitude and high-UV flux environment of the Tibetan locale offers new insight into rock varnish formation processes in a terrestrial environment that displays some attributes similar to those expected on early Mars. Microprobe measurements reveal that Mn enhancements in varnish are two orders of magnitude above the dust source, but Fe is only enhanced by a factor of three. Manganese-enhancing bacterial forms are not abundant but are still approximately 3 times more common than in Mojave and Sonoran Desert varnishes. In addition to its occurrence in subaerial positions, Tibetan varnish also occurs in micron-scale "pods" enveloped by silica glaze and as remobilized constituents that have migrated into the underlying weathering rind. A lack of surficial Mn-rich varnish, therefore, might not imply the absence of varnish. In contrast to suggestions that silica glaze might be a good source of microbial fossils and a key to varnish formation, we did not observe any clear microfossil forms entombed in silica glaze; further, there is no gradation between varnish and silica glaze but only distinct contacts. PMID:19663762

  14. Our World: Lunar Rock

    NASA Video Gallery

    Learn about NASA'€™s Lunar Sample Laboratory Facility at Johnson Space Center in Houston, Texas. See how NASA protects these precious moon rocks brought to Earth by the Apollo astronauts. Explore t...

  15. East Candor Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    24 September 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a thick, massive outcrop of light-toned rock exposed within eastern Candor Chasma, part of the vast Valles Marineris trough system. Dark, windblown sand has banked against the lower outcrop slopes. Outcrops such as this in the Valles Marineris chasms have been known since Mariner 9 images were obtained in 1972. However, the debate as to whether these represent sedimentary or igneous rocks has not been settled within the Mars science community. In either case, they have the physical properties of sedimentary rock (that is, they are formed of fine-grained materials), but some igneous rocks made up of volcanic ash may also exhibit these properties. This image is located near 7.8oS, 65.3oW, and covers an area approximately 3 km (1.9 mi) across. The scene is illuminated by sunlight from the lower left.

  16. Focus on the Rock.

    ERIC Educational Resources Information Center

    Shewell, John

    1994-01-01

    Describes historical accounts of the manipulation and importance of the Earth and its mineral resources. A foldout, "Out of the Rock," provides a collection of activities and information that helps make integration of the aforementioned concepts easy. (ZWH)

  17. Terby's Layered Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    14 March 2004 Layered rock outcrops are common all across Mars, and the Mars rover, Opportunity, has recently investigated some layered rocks in Meridiani Planum. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows layered sedimentary rocks in northern Terby Crater, located just north of the giant Hellas Basin near 27.5oS, 285.8oW. Hundreds of layers are exposed in a deposit several kilometers thick within Terby. A history of events that shaped the northern Hellas region is recorded in these rocks, just waiting for a person or robot to investigate. The picture covers an area 3 km (1.9 mi) across. Sunlight illuminates the scene from the left.

  18. Ancient Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-469, 31 August 2003

    The terraced area in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image is an outcropping of ancient, sedimentary rock. It occurs in a crater in western Arabia Terra near 10.8oN, 4.5oW. Sedimentary rocks provide a record of past environments on Mars. Field work will likely be required to begin to get a good understanding of the nature of the record these rocks contain. Their generally uniform thickness and repeated character suggests that deposition of fine sediment in this crater was episodic, if not cyclic. These rocks might be indicators of an ancient lake, or they might have been deposited from grains settling out of an earlier, thicker, martian atmosphere. This image covers an area 3 km (1.9 mi) across and is illuminated from the lower left.

  19. Layered Rock Ahead

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Now that solar conjunction is over so that communication between Earth and Mars is no longer blocked by the Sun, NASA's Mars Exploration Rover Spirit is continuing its trek through the 'Columbia Hills' in Gusev Crater. Straight ahead, in the foreground of this image, is a horizontally layered rock dubbed 'Tetl,' which scientists hope to investigate. Layering can be either volcanic or sedimentary in origin; researchers aim to determine which of these processes created this rock. If for some reason this particular rock is not favorably positioned for grinding and examination by the toolbox of instruments on the rover's robotic arm, Spirit will be within short reach of another similar rock, dubbed 'Coba,' just to the right, toward the middle of this image. Spirit took this image with its navigation camera on its 263rd martian day, or sol (Sept. 28, 2004).

  20. Broken Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    18 May 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows broken-up blocks of sedimentary rock in western Candor Chasma. There are several locations in western Candor that exhibit this pattern of broken rock. The manner in which these landforms were created is unknown; it is possible that there was a landslide or a meteoritic impact that broke up the materials. One attribute that is known: in some of these cases, it seems that the rock was broken and then buried by later sedimentary rocks, before later being exhumed so that they can be seen from orbit today.

    Location near: 6.9oS, 75.5oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  1. Rock in Its Elements

    ERIC Educational Resources Information Center

    MacCluskey, Thomas

    1969-01-01

    A discussion of the following musical elements of rock: rhythm, melody, harmony, and form. A impromptu analysis made at a session of the Youth Music Symposium, July 25, 1969. Remarks transcribed from tape. (Author/AP)

  2. Weathering of Thermal Control Coatings

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Tuan, George C.; Westheimer, David T.; Peters, Wanda C.; Kauder, Lonny R.; Triolo, Jack J.

    2007-01-01

    Spacecraft radiators reject heat to their surroundings. Radiators can be deployable or mounted on the body of the spacecraft. NASA's Crew Exploration Vehicle is to use body mounted radiators. Coatings play an important role in heat rejection. The coatings provide the radiator surface with the desired optical properties of low solar absorptance and high infrared emittance. These specialized surfaces are applied to the radiator panel in a number of ways, including conventional spraying, plasma spraying, or as an applique. Not specifically designed for a weathering environment, little is known about the durability of conventional paints, coatings, and appliques upon exposure to weathering and subsequent exposure to solar wind and ultraviolet radiation exposure. In addition to maintaining their desired optical properties, the coatings must also continue to adhere to the underlying radiator panel. This is a challenge, as new composite radiator panels are being considered as replacements for the aluminum panels used previously. Various thermal control paints, coatings, and appliques were applied to aluminum and isocyanate ester composite coupons and were exposed for 30 days at the Atmospheric Exposure Site of the Kennedy Space Center s Beach Corrosion Facility for the purpose of identifying their durability to weathering. Selected coupons were subsequently exposed to simulated solar wind and vacuum ultraviolet radiation to identify the effect of a simulated space environment on the as-weathered surfaces. Optical properties and adhesion testing were used to document the durability of the paints and coatings. The purpose of this paper is to present the results of the weathering testing and to summarize the durability of several thermal control paints, coatings, and appliques to weathering and postweathering environments.

  3. Search for magnetic minerals in Martian rocks: Overview of the Rock Abrasion Tool (RAT) magnet investigation on Spirit and Opportunity

    NASA Astrophysics Data System (ADS)

    Goetz, Walter; Leer, Kristoffer; Gunnlaugsson, Haraldur P.; Bartlett, Paul; Basso, Brandon; Bell, Jim; Bertelsen, Preben; Binau, Charlotte S.; Chu, Phillip C.; Gorevan, S.; Hansen, Mikkel F.; Hviid, Stubbe F.; Kinch, Kjartan M.; Klingelhöfer, Göstar; Kusack, Alastair; Madsen, Morten B.; Ming, Douglas W.; Morris, Richard V.; Mumm, Erik; Myrick, Tom; Olsen, Malte; Squyres, Steven W.; Wilson, Jack; Yen, Albert

    2008-05-01

    The Rock Abrasion Tool (RAT) on board the Mars Exploration Rovers (MER) is a grinding tool designed to remove dust coatings and/or weathering rinds from rocks and expose fresh rock material. Four magnets of different strengths that are built into the structure of the RAT have been attracting substantial amounts of magnetic material during RAT activities from rocks throughout both rover missions. The RAT magnet experiment as performed on Spirit demonstrates the presence of a strongly ferrimagnetic phase in Gusev crater rocks, which based on Mössbauer and visible/near-infrared reflectance spectra is interpreted as magnetite. The amount of abraded rock material adhering to the magnets varied strongly during the mission and is correlated in a consistent way to the amount of magnetite inferred from Mössbauer spectra for the corresponding rock. The RAT magnet experiment as performed on Opportunity also indicates the presence of a strongly ferrimagnetic phase in outcrops, such as magnetite or an altered version of magnetite. However, the evidence is weaker than in the case of Spirit. According to data from the α particle X-ray spectrometer (APXS) and the Mössbauer spectrometer (MB), the Eagle crater outcrops should not contain magnetite and their magnetization should not exceed 0.03 A m2 kg-1. However, this assertion seems to be in contradiction with the results of the RAT magnet experiment. The evidence for a strongly ferrimagnetic phase at low abundance in the Meridiani outcrops is discussed.

  4. The micromorphological approach to rock-lichen interactions

    NASA Astrophysics Data System (ADS)

    Terribile, F.; Vingiani, S.; Adamo, P.

    2012-04-01

    Biological factors associated with lichen growth play a major role in the weathering of minerals on bare rocks. Research on this topic over the last decades has demonstrated that a variety of interactions exist between these organisms and substrates and that further progresses in the study of the rock-lichen relationships rely on modern instrumental and analytical techniques application. In this investigation a micromorphological methodology has been produced in order to study the weathering phenomena resulting from the growth of six crustose (Lecidea fuscoatra, Lecanora sulfurea, Rinodina beccariana, Lepraria sp., Rhizocarpon geographicum and Diploscistes actinostomus) and three foliose (Xanthoria calcicola, Xanthoria ectaneoides and Parmelia conspersa) lichen species growing on volcanic and metamorphic rocks. Lecidea fuscoatra was collected on phonolitic tefrite from Mt. Etna (Sicily), Parmelia conspersa on tefritic leucitite from Mt. Vesuvius (Campania), Lepraria sp. and Rhizocarpon geographicum on granite from Alghero (Sardinia), Xanthoria ectaneoides on massive serpentinite from Impruneta (Toscana), Lecanora sulfurea, Rinodina beccariana and Diploscistes actinostomus on metal-bearing schist from Argentiera (Sardinia). The methodology implies a multi-resolution analysis of rock-lichen undisturbed samples ranging from direct (OM) to electron microscopic (SEM/EDS) observations. Different litologies covered by lichens were sampled in the field in selected locations (1st level of resolution). Samples were analysed by both direct observation and stereomicroscopy in order to spot the most relevant zones for further study (2nd level of resolution). Such parts were impregnated with polyester resin to obtain a series of thin sections (30 micrometer thick). The thin sections were analysed by optical microscopy using point counting procedures (3rd level of resolution). Bulk and undisturbed microsamples, separated from the most representative weathering sites by

  5. Rock slope stability

    SciTech Connect

    Kliche, C.A.

    1999-07-01

    Whether you're involved in surface mine design, surface mine production, construction, education, or regulation, this is an important new book for your library. It describes the basic rock slope failure modes and methods of analysis--both kinematic and kinetic techniques. Chapters include geotechnical and geomechanical analysis techniques, hydrology, rock slope stabilization techniques, and geotechnical instrumentation and monitoring. Numerous examples, drawings and photos enhance the text.

  6. Effects of weathering on the RbSr and KAr ages of biotite from the Morton Gneiss, Minnesota

    USGS Publications Warehouse

    Goldich, S.S.; Gast, P.W.

    1966-01-01

    Weathering has drastically reduced the RbSr and, to a lesser extent, the KAr age of biotite from the Morton Gneiss of southwestern Minnesota. The ages are approximately 75% and 25% lower than the corresponding ages for biotite from the fresh gneiss. The effects of even incipient weathering cannot be neglected in RbSr dating of biotite and, by analogy, of feldspar and whole-rock samples. ?? 1966.

  7. Ionospheric climate and weather modeling

    SciTech Connect

    Schunk, R.W.; Sojka, J.J.

    1988-03-01

    Simulations of the ionospheric model of Schunk et al. (1986) have been used for climatology and weather modeling. Steady state empirical models were used in the climatology model to provide plasma convection and particle precipitation patterns in the northern high-latitude region. The climatology model also depicts the ionospheric electron density and ion and electron temperatures for solar maximum, winter solstice, and strong geomagnetic activity conditions. The weather model describes the variations of ionospheric features during the solar cycle, seasonal changes, and geomagnetic activity. Prospects for future modeling are considered. 23 references.

  8. Earth Observation Services Weather Imaging

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Microprocessor-based systems for processing satellite data offer mariners real-time images of weather systems, day and night, of large areas or allow them to zoom in on a few square miles. Systems West markets these commercial image processing systems, which have significantly decreased the cost of satellite weather stations. The company was assisted by the EOCAP program, which provides government co-funding to encourage private investment in, and to broaden the use of, NASA-developed technology for analyzing information about Earth and ocean resources.

  9. Petrology of metamorphic rocks

    SciTech Connect

    Suk, M.

    1983-01-01

    ''Petrology of Metamorphic Rocks'' reviews Central European opinions about the origin and formation of metamorphic rocks and their genetic systems, confronting the works of such distinguished European scientists as Rosenbusch, Becke, Niggli, Sander, Eskola, Barth and others with present-day knowledge and the results of Soviet and American investigations. The initial chapters discuss the processes that give rise to metamorphic rocks, and the main differences between regional metamorphism and other types of alterations, the emphasis being laid on the material characteristic of the processes of metamorphism, metasomatism and ultrametamorphism. Further chapters give a brief characterization of research methods, together with a detailed genetic classification based on the division of primary rocks into igneous rocks, sediments and ore materials. The effects of metamorphic alterations and those of the properties of the primary rocks are analyzed on the basis of examples taken chiefly from the Bohemian Massif, the West Carpathians, other parts of the European Variscides, from the crystalline Scandinavian Shelf in Norway and Finland, and from the Alps. Typical examples are documented by a number of charts, photographs and petrographical - particularly petrochemical - data.

  10. Chemical weathering in a tropical watershed, Luquillo Mountains, Puerto Rico: I. Long-term versus short-term weathering fluxes

    USGS Publications Warehouse

    White, A.F.; Blum, A.E.; Schulz, M.S.; Vivit, D.V.; Stonestrom, D.A.; Larsen, M.; Murphy, S.F.; Eberl, D.

    1998-01-01

    The pristine Rio Icacos watershed in the Luquillo Mountains in eastern Puerto Rico has the fastest documented weathering rate of silicate rocks on the Earth's surface. A regolith propagation rate of 58 m Ma-1 calculated from iso-volumetric saprolite formation from quartz diorite, is comparable to the estimated denudation rate (25-50 Ma-1) but is an order of magnitude faster than the global average weathering rate (6 Ma-1). Weathering occurs in two distinct environments; plagioclase and hornblende react at the saprock interface and biotite and quartz weather in the overlying thick saprolitic regolith. These environments produce distinctly different water chemistries, with K, Mg, and Si increasing linearly with depth in saprolite porewaters and with stream waters dominated by Ca, Na, and Si. Such differences are atypical of less intense weathering in temperate watersheds. Porewater chemistry in the shallow regolith is controlled by closed-system recycling of inorganic nutrients such as K. Long-term elemental fluxes through the regolith (e.g., Si = 1.7 ?? 10-8 moles m-2 s-1) are calculated from mass losses based on changes in porosity and chemistry between the regolith and bedrock and from the age of the regolith surface (200 Ma). Mass losses attributed to solute fluxes are determined using a step-wise infiltration model which calculates mineral inputs to the shallow and deep saprolite porewaters and to stream water. Pressure heads decrease with depth in the shallow regolith (-2.03 m H2O m-1), indicating that both increasing capillary tension and graviometric potential control porewater infiltration. Interpolation of experimental hydraulic conductivities produces an infiltration rate of 1 m yr-1 at average field moisture saturation which is comparable with LiBr tracer tests and with base discharge from the watershed. Short term weathering fluxes calculated from solute chemistries and infiltration rates (e.g., Si = 1.4 ?? 10-8 moles m-2 s-1) are compared to watershed

  11. Lithium Isotope Systematics of Rift-related Alkaline Igneous Rocks

    NASA Astrophysics Data System (ADS)

    Halama, R.; McDonough, W. F.; Rudnick, R. L.; Trumbull, R.; Klaudius, J.; Keller, J.; Taubald, H.

    2006-05-01

    Intracontinental alkaline igneous rocks from the Proterozoic Gardar Province (Greenland), the Cretaceous Damaraland Province (Namibia), the Tertiary Kaiserstuhl complex (Germany) and from the Holocene volcano Oldoinyo Lengai (Tanzania) were analyzed to characterize Li isotopic compositions of their mantle sources and to determine the processes affecting δ7Li in alkaline igneous rocks. The inferred mantle Li isotope signatures of the primitive alkaline rocks (δ7Li = +1 to +7) are similar to those of present- day MORB, OIB and carbonatites, and appear to be relatively constant in time and space. Gabbros from the Gardar Province define a relatively small field of Li isotope compositions (δ7Li = +4 to +7). Mineral separates (clinopyroxene, plagioclase) mostly overlap with the whole-rock values, which we interpret to reflect the δ7Li of the mantle sources of the gabbros. Mantle-like δ7Li values are also observed for primitive alkaline rocks from the other regions. Li isotope compositions in more differentiated rocks (syenites, phonolites and rhyolites) are highly variable (+11 to -22 per mil) and reflect a diversity of evolutionary processes that may vary from complex to complex. δ7Li values vary independently of Sr and Nd isotope values and indices of differentiation (e.g. MgO content) or weathering (e.g. LOI). Consistently light δ7Li values (+2 to -22) occur in Gardar syenites associated with a carbonatite. These may be explained by weathering and sub-solidus alteration, as indicated by petrographic observations. Alternatively, fluid-assisted diffusion processes, related to a fenitizing fluid from the carbonatite, may have led to extreme Li isotope fractionation. Whole-rock oxygen isotope analyses will be carried out to evaluate interaction with meteoric water, which would be reflected in a decrease in δ18O compared to magmatic values. The heaviest Li isotopic composition (+11 per mil) was obtained for a rhyolite, probably related to the presence of quartz

  12. Space weathering on Mercury: Simulation of plagioclase weathering

    NASA Astrophysics Data System (ADS)

    Sasaki, Sho; Hiroi, Takahiro; Helbert, Jorn; Arai, Tomoko

    The optical property of the surfaces of airless silicate bodies such as the Moon, Mercury and asteroids should change in time. Typical characteristics of the change, "space weathering", are darkening, spectral reddening, and attenuation of absorption bands in reflectance spectra. The space weathering is caused by the formation of nanophase metallic iron particles in amorphous surface coatings from the deposition of ferrous silicate vapor, which was formed by high velocity dust impacts as well as irradiation of the solar wind ions. Nanophase iron particles have been confirmed in the lunar soil coating [1]. Moreover, experimental studies using pulse laser showed the formation of nanophase ion particles on the surface should control the spectral darkening and reddening [2]. Mariner 10 and MESSENGER spacecraft showed that Mercury has more impact craters asso-ciated with bright rays than the Moon. The space weathering rate on Mercury's surface might be slower than that of the lunar surface, although dust flux and solar wind flux causing the weathering should be one order of magnitude of greater on Mercury than on the Moon [3]. The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) on board MES-SENGER measured reflectance spectra from Mercury's surface during the two flybys in 2008 [4] with the wavelength range between 0.2 and 1.3 microns. MASCS spectra show variation in the slope, which can be explained by lunar-like maturity trend due to the difference of space weathering degree. Spectral absorption in the UV range shows that the ferrous oxide (Fe2+) content in average surface/subsurface material is as low as a few weight percent. This could explain apparent low weathering rate on Mercury. Growth of size of nanophase iron could also have lowered the weathering degree. Size of nanophase iron particles should increase by Ostwald ripening under high temperature of several 100C [5] . And repeated irradiation by high velocity dust impacts as well as solar wind

  13. Raman spectroscopic characterization of a highly weathered basalt: Igneous mineralogy, alteration products, and a microorganism

    NASA Astrophysics Data System (ADS)

    Wang, Alian; Jolliff, Bradley L.; Haskin, Larry A.

    On-surface identification of minerals on Mars is likely to depend mainly on observations of rocks and soils as found, without access to fresh surfaces or other sample preparation. Both the original mineralogy of rocks and their alteration mineralogy will be important. To determine the capability of Raman spectroscopy to provide good mineralogical characterization of an altered igneous rock such as might be encountered on Mars, we have analyzed the heavily weathered, exterior surface of a cobble of Keweenawan basalt and compared the results with those from a roughly cut, unpolished interior surface, using a Raman point-counting method. Despite ubiquitous hematite, a strong Raman scatterer, and despite considerable alteration, original igneous plagioclase and pyroxene were identified and their approximate proportions determined from point-counting traverses on the original surface of the rock. Saponite, an alteration product, was easily identified on the freshly cut surface but could only occasionally be identified on the weathered surface, where saponite-rich areas were highly photoluminescent. Amygdular fill gave strong spectra of calcite and thomsonite (a zeolite). Tiny, sparse crustose lichen gave clear spectra of their waxy organic coating. On the basis of the surface Raman spectra alone, the rock could be identified as a mafic rock, probably basaltic, that was hydrothermally altered in an oxidizing environment at a temperature between ~250 and ~350°C.

  14. Space Weather Around the World: An IHY Education Program

    NASA Astrophysics Data System (ADS)

    Thieman, J. R.; Ng, C.; Hawkins, I.; Lewis, E.; Cline, T.

    2007-05-01

    Fifty years ago the International Geophysical Year organized a unique and unprecedented program of research that united 60,000 scientists from 66 nations to study global phenomena concerning the Earth and its space environment. In that same spirit, "Space Weather Around the World" is a program to coordinate and facilitate the involvement of NASA heliophysics missions and scientists to inspire and educate a world-wide audience about the International Heliophysical Year (IHY). We will use the popular Sun-Earth Day annual event framework sponsored by the Sun-Earth Connection Education Forum to promote IHY science and the spirit of international collaboration. The theme for the March 2007 Sun-Earth Day: "IHY: Living in the Atmosphere of the Sun" was selected a year ago in anticipation of the IHY celebration. These efforts will be expanded through a series of coordinated programs under the theme "Space Weather Around the World" for Sun-Earth Day 2008. We will produce a live broadcast from China of the total solar eclipse on August 1st 2008 as the central event, highlighting investigations associated with the eclipse by the international heliophysics community. Additional collaborative efforts will include: a Space Weather Media Maker web-tool to allow educators and scientists to create their own multi-media resource to enhance teaching and learning at all levels; Rock-n-Sol, a musical composition by children internationally inspired by space weather and incorporating sonifications of solar data; and Space Weather Action Centers for students to track a solar storm featuring podcasts of multi-cultural perspectives on IHY. The anticipated audience would be millions of people internationally The science and E/PO heliophysics community has an exciting story to tell about IHY, and we look forward to the opportunity to share it globally.

  15. Massive magnesium depletion and isotope fractionation in weathered basalts

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Ming; Teng, Fang-Zhen; Rudnick, Roberta L.; McDonough, William F.; Cummings, Michael L.

    2014-06-01

    Magnesium isotopes have been shown to fractionate significantly during continental weathering, however, the degree and direction of fractionation varies from one study to the next, and the main factors that control Mg isotope fractionation during weathering have yet to be delineated. Here, we report Mg contents and isotopic compositions for two ∼10 m deep drill cores through bauxites developed on Columbia River Basalts (CRBs). Samples from these two drill cores have very low MgO contents (0.12-0.25 wt.%) and variable but high δ26Mg values (from -0.1 to up to +1.8, the heaviest isotopic composition ever reported for Mg) relative to the average values of fresh CRBs (δ26Mg = -0.23 ± 0.07 and MgO = 5.9 wt.%). These features reflect the near complete loss of Mg in the isotopically heavy regolith. The most highly weathered bauxites at the tops of the profiles have the lowest δ26Mg values, reflecting the addition of isotopically light eolian dust. Excluding these samples, δ26Mg in bauxites displays a weak, positive correlation with gibbsite abundance, suggesting that gibbsite preferentially retains 26Mg in the bauxites. The integrated Mg isotopic fractionation factors between bauxite and fluid (Δ26Mgbauxite-fluid), inferred from Rayleigh fractionation calculations, vary from 0.05‰ to 0.4‰, which is similar to the range inferred from previous studies of igneous rock weathering profiles, though none of these previous studies found the extremely heavy δ26Mg and massive Mg depletion seen here. Collectively, studies of weathering profiles suggest loss of isotopically light Mg from the continents, which must contribute to the very light δ26Mg seen in river water and seawater.

  16. Verification of Space Weather Forecasts using Terrestrial Weather Approaches

    NASA Astrophysics Data System (ADS)

    Henley, E.; Murray, S.; Pope, E.; Stephenson, D.; Sharpe, M.; Bingham, S.; Jackson, D.

    2015-12-01

    The Met Office Space Weather Operations Centre (MOSWOC) provides a range of 24/7 operational space weather forecasts, alerts, and warnings, which provide valuable information on space weather that can degrade electricity grids, radio communications, and satellite electronics. Forecasts issued include arrival times of coronal mass ejections (CMEs), and probabilistic forecasts for flares, geomagnetic storm indices, and energetic particle fluxes and fluences. These forecasts are produced twice daily using a combination of output from models such as Enlil, near-real-time observations, and forecaster experience. Verification of forecasts is crucial for users, researchers, and forecasters to understand the strengths and limitations of forecasters, and to assess forecaster added value. To this end, the Met Office (in collaboration with Exeter University) has been adapting verification techniques from terrestrial weather, and has been working closely with the International Space Environment Service (ISES) to standardise verification procedures. We will present the results of part of this work, analysing forecast and observed CME arrival times, assessing skill using 2x2 contingency tables. These MOSWOC forecasts can be objectively compared to those produced by the NASA Community Coordinated Modelling Center - a useful benchmark. This approach cannot be taken for the other forecasts, as they are probabilistic and categorical (e.g., geomagnetic storm forecasts give probabilities of exceeding levels from minor to extreme). We will present appropriate verification techniques being developed to address these forecasts, such as rank probability skill score, and comparing forecasts against climatology and persistence benchmarks. As part of this, we will outline the use of discrete time Markov chains to assess and improve the performance of our geomagnetic storm forecasts. We will also discuss work to adapt a terrestrial verification visualisation system to space weather, to help

  17. Clay mineral formation and transformation in rocks and soils

    USGS Publications Warehouse

    Eberl, D.D.

    1983-01-01

    Three mechanisms for clay mineral formation (inheritance, neoformation, and transformation) operating in three geological environments (weathering, sedimentary, and diagenetic-hydrothermal) yield nine possibilities for the origin of clay minerals in nature. Several of these possibilities are discussed in terms of the rock cycle. The mineralogy of clays neoformed in the weathering environment is a function of solution chemistry, with the most dilute solutions favoring formation of the least soluble clays. After erosion and transportation, these clays may be deposited on the ocean floor in a lateral sequence that depends on floccule size. Clays undergo little reaction in the ocean, except for ion exchange and the neoformation of smectite; therefore, most clays found on the ocean floor are inherited from adjacent continents. Upon burial and heating, however, dioctahedral smectite reacts in the diagenetic environment to yield mixed-layer illite-smectite, and finally illite. With uplift and weathering, the cycle begins again. Refs.

  18. Long-term stability of global erosion rates and weathering during late-Cenozoic cooling.

    PubMed

    Willenbring, Jane K; von Blanckenburg, Friedhelm

    2010-05-13

    Over geologic timescales, CO(2) is emitted from the Earth's interior and is removed from the atmosphere by silicate rock weathering and organic carbon burial. This balance is thought to have stabilized greenhouse conditions within a range that ensured habitable conditions. Changes in this balance have been attributed to changes in topographic relief, where varying rates of continental rock weathering and erosion are superimposed on fluctuations in organic carbon burial. Geological strata provide an indirect yet imperfectly preserved record of this change through changing rates of sedimentation. Widespread observations of a recent (0-5-Myr) fourfold increase in global sedimentation rates require a global mechanism to explain them. Accelerated uplift and global cooling have been given as possible causes, but because of the links between rates of erosion and the correlated rate of weathering, an increase in the drawdown of CO(2) that is predicted to follow may be the cause of global climate change instead. However, globally, rates of uplift cannot increase everywhere in the way that apparent sedimentation rates do. Moreover, proxy records of past atmospheric CO(2) provide no evidence for this large reduction in recent CO(2) concentrations. Here we question whether this increase in global weathering and erosion actually occurred and whether the apparent increase in the sedimentation rate is due to observational biases in the sedimentary record. As evidence, we recast the ocean dissolved (10)Be/(9)Be isotope system as a weathering proxy spanning the past approximately 12 Myr (ref. 14). This proxy indicates stable weathering fluxes during the late-Cenozoic era. The sum of these observations shows neither clear evidence for increased erosion nor clear evidence for a pulse in weathered material to the ocean. We conclude that processes different from an increase in denudation caused Cenozoic global cooling, and that global cooling had no profound effect on spatially and

  19. Space Weathering of Intermediate-Size Soil Grains in Immature Apollo 17 Soil 71061

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; Robinson, G. A.; McKay, D. S.

    2005-01-01

    Understanding space weathering, which is caused by micrometeorite impacts, implantation of solar wind gases, radiation damage, chemical effects from solar particles and cosmic rays, interactions with the lunar atmosphere, and sputter erosion and deposition, continues to be a primary objective of lunar sample research. Electron beam studies of space weathering have focused on space weathering effects on individual glasses and minerals from the finest size fractions of lunar soils [1] and patinas on lunar rocks [2]. We are beginning a new study of space weathering of intermediate-size individual mineral grains from lunar soils. For this initial work, we chose an immature soil (see below) in order to maximize the probability that some individual grains are relatively unweathered. The likelihood of identifying a range of relatively unweathered grains in a mature soil is low, and we plan to study grains ranging from pristine to highly weathered in order to determine the progression of space weathering. Future studies will include grains from mature soils. We are currently in the process of documenting splash glass, glass pancakes, craters, and accretionary particles (glass and mineral grains) on plagioclase from our chosen soil using high-resolution field emission scanning electron microscopy (FESEM). These studies are being done concurrently with our studies of patinas on larger lunar rocks [e.g., 3]. One of our major goals is to correlate the evidence for space weathering observed in studies of the surfaces of samples with the evidence demonstrated at higher resolution (TEM) using cross-sections of samples. For example, TEM studies verified the existence of vapor deposits on soil grains [1]; we do not yet know if they can be readily distinguished by surfaces studies of samples. A wide range of textures of rims on soil grains is also clear in TEM [1]; might it be possible to correlate them with specific characteristics of weathering features seen in SEM?

  20. Geomorphic controls on availability of weathering-derived nutrients across an erosional gradient in the Andes

    NASA Astrophysics Data System (ADS)

    West, A.; Torres, M. A.; Kleinsasser, E.; Clark, K.; Asner, G. P.; Malhi, Y.; Quesada, C.

    2013-12-01

    Rock-derived nutrients are thought to play important roles in determining ecosystem productivity and function, particularly in tropical forests. Variation in the availability of key nutrients such as P and Ca has been attributed to changes in the supply from chemical weathering of bedrock minerals, with a general conceptual model that younger soils with higher weathering rates are capable of supplying more nutrients compared to older soils with lower weathering rates (e.g. Vitousek et al., 2003). In this study we present data from an elevational gradient in the eastern Andes of Peru, illustrating how the relationship between weathering and nutrient availability is manifest in an active erosional system. Our data suggest that weathering, driven by erosional supply of primary minerals, is important in supplying nutrients. However, there is complexity in this relationship that may be associated with the geomorphic controls on weathering geochemistry and hydrochemistry, including weathering that takes place at greater depths when erosion rates are higher (e.g. West, 2012). We compare measured weathering rates with nutrient status of soils and vegetation across a transect from high elevations in the Andes to low elevations in the foreland floodplain. Weathering rates determined from the dissolved chemistry of river samples are highest at high elevation sites in the Andes. Mineral weathering rates are significant in the floodplain, which we attribute to chemical reworking of material eroded from the Andes, but rates of mineral weathering are not as high in the floodplain as in the montane sites. Although Ca supply is highest in the mountains, the foliar Ca and Ca available in soils is lower than in the floodplain. We will explore hydrochemical reasons for this difference, which may be due to where Ca release takes place relative to the vegetation root zone. We will also explore the supply of P from weathering in relation to observed nutrient availability, based on