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1

Accelerated Weathering of Rocks.  

National Technical Information Service (NTIS)

The project concerns correlation between weathering indices obtained from samples of one type of sedimentary rock (graywacke) and those obtained after laboratory agency tests of the same rocks. Study is made of the process of natural alteration in three s...

L. Aires-Barros

1977-01-01

2

Space Weathering of Rocks  

NASA Technical Reports Server (NTRS)

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.

Noble, Sarah

2011-01-01

3

Rocks and Weathering  

NSDL National Science Digital Library

Sedimentary, igneous and metamorphic rocks, weathering, erosion and transport, and the rock cycle are explained in this resource for students through written content, interactive content, audio, video and games. A multiple choice test is included. Students may score their tests and the correct responses will be given.

4

Weathering of rock 'Ginger'  

NASA Technical Reports Server (NTRS)

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).

1997-01-01

5

Rocks, Weathering, and Erosional Landscapes  

NSDL National Science Digital Library

Students will identify principal rock forming silicate minerals and distinguish their relative stability when exposed to weathering; identify sedimentary, igneous and metamorphic rocks and deduce the relative resistance based on mineral composition and texture;and finally relate erosional landscapes to the differential weathering and erosion of rocks of varying strengths. Designed for a geomorphology course

Hanson, Lindley

6

Space Weathering of Lunar Rocks  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

7

Effect of Microbial Weathering on Carbonate Rocks  

NASA Astrophysics Data System (ADS)

The interaction between microorganisms and minerals can facilitate the process of exogenic biogeochemical reaction, which is one of the important research contents in exogenic geochemistry. Microbes and their geological effects were summarized, and a variety of microbial weathering phenomena toward carbonate rocks, especially on different microcosmic scales, were analyzed. Weathering products and mechanisms of carbonate rocks by microbes were also expounded. The authors put forward four microbial weathering mechanisms of carbonate rocks: (1) microorganisms grow on rock surface or in crevices, resulting in bio-corrosion, bio-erosion, and boring, and accelerate rock decomposition and weathering; (2) boring meshes produced by microbial colony could increase the efficient superficial area of chemical denudation of rocks and could lead to the intensification of rock surface weathering to promote mechanical erosion, and the microbial destruction and loosing of cementation structure of rock particles would also accelerate the decomposition of mineral particles; (3) rock weathering can be intensified by the effects of microbial water-keeping, acidification of organic acids secreted by microorganisms, and the release of CO 2 induced by microbial respiration onto rock surface; (4) microorganisms obtain nutrition from rock surface to produce complicated organic ligands and promote the release of mineral elements in the growing process of microorganisms. Finally, how to carry out studies on the microbial weathering of carbonate rocks was proposed. The authors suggest to comprehensively exploit local low-grade mineral resources, which contain potassium and phosphate, and accelerate soil formation and evolution in karst regions by using microbial technology.

LIAN, Bin; CHEN, Ye; ZHU, Lijun; YANG, Ruidong

8

Rock strength reductions during incipient weathering  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

9

Modeling rock weathering in small watersheds  

NASA Astrophysics Data System (ADS)

Many mountainous watersheds are conceived as aquifer media where multiple groundwater flow systems have developed (Tóth, 1963), and as bimodal landscapes where differential weathering of bare and soil-mantled rock has occurred (Wahrhaftig, 1965). The results of a weathering algorithm (Pacheco and Van der Weijden, 2012a, 2014), which integrates topographic, hydrologic, rock structure and chemical data to calculate weathering rates at the watershed scale, validated the conceptual models in the River Sordo basin, a small watershed located in the Marão cordillera (North of Portugal). The coupling of weathering, groundwater flow and landscape evolution analyses, as accomplished in this study, is innovative and represents a remarkable achievement towards regionalization of rock weathering at the watershed scale. The River Sordo basin occupies an area of approximately 51.2 km2 and was shaped on granite and metassediment terrains between the altitudes 185-1300 m. The groundwater flow system is composed of recharge areas located at elevations >700 m, identified on the basis of ?18O data. Discharge cells comprehend terminations of local, intermediate and regional flow systems, identified on the basis of spring density patterns, infiltration depth estimates based on 87Sr/86Sr data, and spatial distributions of groundwater pH and natural mineralization. Intermediate and regional flow systems, defined where infiltration depths >125 m, develop solely along the contact zone between granites and metassediments, because fractures in this region are profound and their density is very large. Weathering is accelerated where rocks are covered by thick soils, being five times faster relative to sectors of the basin where rocks are covered by thin soils. Differential weathering of bare and soil-mantled rock is also revealed by the spatial distribution of calculated aquifer hydraulic diffusivities and groundwater travel times.

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

2014-05-01

10

Deeply weathered basement rocks in Norway  

NASA Astrophysics Data System (ADS)

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 observations from the Norwegian shelf, where grussy type of weathered bedrock was found buried under Mesozoic sediments, leads to the conclusion that coarse-grained, clay-poor saprolite does not necessarily indicate a young age of weathering but could in fact be of Early Mesozoic age or even older. The Late Jurassic to Early Cretaceous faults in the Lofoten-Vesterålen area are for instance little affected by weathering processes. With the goal to refine our understanding of the complex weathering processes and to constrain them in time, the NGU is establishing a new K-Ar laboratory for the dating and characterization of illite grown authigenically in the saprolites. It is expected that the data generated therein will contribute new quantitative constraints to the long-lasting debate as to the age of weathering processes in Scandinavia.

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

2014-05-01

11

Mechanism and effect of chemical weathering of sedimentary rocks  

Microsoft Academic Search

The mineralogy, geochemistry and physical and mechanical properties of rocks from four weathering profiles of Miocene to Pleistocene mudstones and sandstones in Japan showed that chemical weathering of sedimentary rocks is characterized by sequential reaction between percolating groundwater and rock-forming minerals. Pyrite, a common mineral contained in sedimentary rocks, is especially important in these sequential reactions. Pyrite is oxidized by

M. Chigira; T. Oyama

2000-01-01

12

Directable Weathering of Concave Rock Using Curvature Estimation  

Microsoft Academic Search

We address the problem of directable weathering of exposed concave rock for use in computer-generated animation or games. Previous weathering models that admit concave surfaces are computationally inefficient and difficult to control. In nature, the spheroidal and cavernous weathering rates depend on the surface curvature. Spheroidal weathering is fastest in areas with large positive mean curvature and cavernous weathering is

Michael D. Jones; McKay Farley; Joseph Butler; Matthew Beardall

2010-01-01

13

Take a Tumble: Weathering and Erosion Using a Rock Tumbler  

ERIC Educational Resources Information Center

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…

Coffey, Patrick; Mattox, Steve

2006-01-01

14

Bibliography on the Chemical Weathering of Granitic Rocks,  

National Technical Information Service (NTIS)

This bibliography lists many of the papers in the international published geological geomorphological and soils literature that discuss the chemical weathering of rocks often considered non-soluble. Emphasis is placed on granitic rocks. Keywords: Chemical...

A. J. Gerrard J. Ehlen

1988-01-01

15

On the weathering of Martian igneous rocks  

NASA Technical Reports Server (NTRS)

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.

Dreibus, G.; Waenke, H.

1992-01-01

16

Science Sampler: Chemical weathering--Where did the rocks go?  

NSDL National Science Digital Library

This lesson is part of a larger Earth science unit that combines the concepts of the rock cycle and the water cycle and how they interact to change landforms. The authors refer to it as the "make it and then break it" unit. They spend half the unit making metamorphic, sedimentary, and igneous rock models, and the second half of the unit weathering and eroding their models and other rocks. Students use the lessons learned to answer an open-ended question describing the process of weathering. They also make decisions regarding the chemical and mechanical weathering on monuments and buildings.

Wallace, Carolyn; Zawicki, Joseph; Harris, Robin

2008-10-01

17

Characterization of weathered acidic volcanic rocks and a weathering classification based on a rating system  

Microsoft Academic Search

It is important to recognize the effect of weathering in the performance of rock in engineering works. The aim of this study\\u000a was to determine the weathering characteristics of acidic volcanic rocks from northwest Turkey and their effects on some engineering\\u000a properties of the rocks. A series of simple and multiple regression and factor analyses suggested that porosity, indirect\\u000a tensile

Fehmi Ar?kan; Re?at Ulusay; Nihal Ayd?n

2007-01-01

18

Bacillus qingshengii sp. nov., a rock-weathering bacterium isolated from weathered rock surface.  

PubMed

A novel type of rock-weathering bacterium was isolated from weathered rock (tuff) surface collected from Dongxiang (Jiangxi, eastern China). Cells of strain G19(T) were Gram-reaction-positive, rod-shaped, endospore-forming and non-motile. The strain was aerobic, catalase- and oxidase-positive, and grew optimally at 30 °C and pH 7.0. On the basis of 16S rRNA gene sequence analysis, strain G19(T) was shown to belong to the genus Bacillus and the closest phylogenetic relatives were Bacillus aryabhattai B8W22(T) (97.4?%) and Bacillus megaterium IAM 13418(T) (97.1?%). The DNA G+C content was 36.7 mol% and the predominant respiratory quinone was MK-7. The major fatty acids were iso-C14?:?0, iso-C15?:?0 and anteiso-C15?:?0. The polar lipid profile of strain G19(T) contained phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and an unidentified lipid. Based on the low level of DNA-DNA relatedness (ranging from 49.4?% to 55.0?%) to these type strains of species of the genus Bacillus and unique phenotypic characteristics, strain G19(T) represents a novel species of the genus Bacillus, for which the name Bacillus qingshengii sp. nov. is proposed. The type strain is G19(T) (?=?CCTCC AB 2013273(T)?=?JCM 19454(T)). PMID:24801156

Xi, Jun; He, Lin-Yan; Huang, Zhi; Sheng, Xia-Fang

2014-07-01

19

A new quantitative weathering classification for igneous rocks  

Microsoft Academic Search

The description and classification of the rocks provide important information for geotechnical modeling in order to predict\\u000a their engineering behaviors. One of the most imperative parameters influencing the engineering behaviors of the rocks is the\\u000a degree of weathering. Therefore, it is evident that a realistic weathering classification is necessary mostly for establishing\\u000a the geotechnical models in the engineering geology studies.

Sener Ceryan; S. Tudes; N. Ceryan

2008-01-01

20

Relationships Between Magnetic Properties and Weathering Indices of Basaltic Rocks  

NASA Astrophysics Data System (ADS)

Performance of geophysical sensors is often hampered by soils and regolith with significant levels of magnetic susceptibility and viscosity, primarily dependent on the amount and form of ferrimagnetic iron oxide minerals present. In order to develop predictive models for the occurrence of such conditions, it is crucial to understand how the magnetic signal evolves during weathering from fresh rock to soil material. Rock weathering leads to destruction of primary minerals, formation of secondary minerals, and concomitant changes in magnetic properties and major-, minor-, and trace-element geochemistry. Previous work has examined relationships between magnetic properties (e.g., magnetic susceptibility) and single-element proxies for overall sample weathering state. In this contribution we study the relationships between bulk geochemical and magnetic characteristics of weathered basaltic rock, and regolith and soils with basaltic parent material. Four samples collected from a corestone formed by spheroidal weathering on the Kohala Peninsula on the Big Island of Hawaii represent the earliest stages of weathering; a series of samples from regolith to the B-horizon for a soil on Kaho'olawe Island represent later weathering stages. Our analysis includes X-Ray Fluorescence Spectroscopy of whole-sample geochemistry and magnetic measurements for a range of temperatures and frequencies. The extent of chemical weathering is assessed by use of a number of common (but Fe-free) major-element weathering indices. Progressive spheroidal weathering involves centripetal migration of a weathering front from joints and fractures into the interior of the joint blocks. As the weathering front passes through a volume of material, fresh or slightly weathered rock is transformed to a primary-mineral-depleted, clay-rich shell. The exfoliated shells farthest from the corestone were the first weathered; shells successively closer to the corestone were more recently transformed. In the Kohala corestone-shell complex, some chemical-weathering indices vary monotonically with total Fe (as Fe2O3), whereas other chemical-weathering indices vary monotonically with magnetic susceptibility. Thus, some Fe-free major-element chemical-weathering indices seem to scale more systematically with soil magnetic properties than others. For more strongly weathered soils from Kaho'olawe, there is a weak relationship between magnetic properties and total Fe. We hope that through the use of Fe-free major-element weathering indices an improved relationship can be developed. Such an improved correlation would benefit phenomenological understanding of geophysical sensor performance in areas with basaltic substrate.

van Dam, R. L.; Velbel, M. A.

2009-05-01

21

The thermal responses of rock art pigments: Implications for rock art weathering in southern Africa  

Microsoft Academic Search

The San rock art of southern Africa is an international heritage subject to degradation and loss resulting from weathering. The paintings occur within rock shelters, where many are exposed to direct solar radiation for varying periods, rather than occurring in dark caves. As part of a study on the factors thought to be impacting weathering, data were collected pertaining to

Kevin Hall; Ian Meiklejohn; Joselito Arocena

2007-01-01

22

Weathering  

NSDL National Science Digital Library

This course handout covers the processes and effects of weathering. The purpose of this handout is to contrast weathering and erosion, contrast and discuss chemical and mechanical weathering, list the products resulting from the chemical weathering of igneous rocks, and list and discuss the factors that influence the type and rate of rock weathering. Many photographs accompany this summary which depict weathered landscapes. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

1995-08-29

23

ROCK WEATHERING CHARACTERISTICS AS RELATIVE-AGE INDICATORS FOR GLACIAL AND POSTGLACIAL LANDFORMS ON MARION ISLAND  

Microsoft Academic Search

Rock weathering characteristics as relative-age indicators are tested on rock surfaces of generally known chronological sequence on Marion Island in the sub-Antarctic. Relict Late Pleistocene glacial bedrock surfaces and glacial deposit rock surfaces provide both Schmidt hammer rebound values and weathering rind thickness indicative of the longest exposure to weathering. While the weathering characteristics could not establish any chronosequence in

P. SUMNER; W. NEL; S. HOLNESS; J. BOELHOUWERS

2002-01-01

24

Subsurface Weathering of Rocks and Soils at Gusev Crater  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

25

Weathering of Fractured Rock in the Deep Critical Zone  

NASA Astrophysics Data System (ADS)

The interfaces where intact bedrock physically and chemically weathers to form regolith, are often hidden deep within the critical zone and are thus difficult to access. However, weathering of primary minerals along bedrock fractures located in the groundwater or deep vadose zones may supply significant weathering products to streams and oceans and influence topography and soil fertility. We investigated the deep critical zone in the Bisley watershed at the Luquillo Critical Zone Observatory from two 9.6 cm diameter boreholes drilled with a hydraulic rotary drill to 37.2 and 27.0 m depth. Continuous core samples through coherent rock were taken using an HQ-wireline barrel. Bulk solid-state chemical analysis and quantitative XRD were performed on rock and saprock samples. Thin sections were examined by optical microscopy, SEM, EDS, and EPMA. A history of low- to moderate-grade metamorphism is reflected by the presence of epidote, prehnite, pyrite, and tourmaline in the fresh rock (visibly un-weathered). Fresh rock also contains abundant plagioclase and Mg-rich chlorite, with lesser quartz, K-spar, and pyroxene. The quartz is microcrystalline and present in variable quantities in the fresh rock, consistent with infiltration of Si-rich hydrothermal fluids. Evidence of reaction-induced porosity development is observed in the visibly un-weathered rock, but the majority of weathering occurs within weathering rinds (<15 mm thick). These rinds are developed on fracture surfaces (and the outer surfaces of exposed corestones) and contain abundant secondary Fe(III)-oxides, which fill pore space, decreasing porosity relative to the core-rind interface. In the case of exposed corestones, the rinds spall off, refresing the surface for continued weathering. In the case of subsurface corestones, rinds grow thicker and sometimes consume rock fragments entirely. Borehole cores revealed repeated zones of highly fractured rock, interpreted as subsurface corestones, embedded within layers of regolith. Some corestones are massive and others are highly fractured. Subsurface corestones are larger and less fractured in the borehole drilled under a ridge, compared to the borehole drilled near a stream channel. As corestone size is thought to be a function of fracture spacing, the location of the valleys and ridges in the watershed may be controlled by the fracture spacing of the underlying bedrock. Drilling terminated in coherent rock, thought to be bedrock based on a model that hypothesized a thickness for the corestone-regolith zone [1]. Both profiles indicate that weathering proceeds 10's of meters below the stream channel; thus weathering depth is not controlled by local base level. Furthermore, weathering rinds on fracture surfaces at depth indicate that water and oxygen are transported below the stream channel; thus not all of the water in the watershed is discharged to the stream. [1] Fletcher and Brantley (2010) Amer. J. Sci 310, 131-164.

Buss, H. L.; Bazilevskaya, E.; Brantley, S. L.; Scatena, F. N.; Schulz, M. S.; White, A. F.

2012-12-01

26

Changes in the weathering of rock surfaces in different geomorphological environments: glacial, nival and coastal  

Microsoft Academic Search

The sclerometer or Schmidt Rock Test Hammer has been broadly applied in geomorphology to estimate the strength of different rock types and to measure the degree of rock weathering. It has been proved that for a rock type, the rebound values are lower in weathered than in fresh rock surfaces. This evidence suggests that if there is any factor that

A. Feal-Pérez; R. Blanco-Chao; A. Pérez-Alberti; J. López-Bedoya; M. Valcárcel-Díaz

2009-01-01

27

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

NASA Technical Reports Server (NTRS)

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.

Gooding, J. L.

1984-01-01

28

Space Weathering of Lunar Rocks and Regolith Grains  

NASA Technical Reports Server (NTRS)

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) are the primary agent in spectral "reddening". More recent work has focused on the nature and abundance of OH/H2O in the lunar regolith using orbital data and samples analyses. Advances in sample preparation techniques have made possible detailed analyses of patina-coated rock surfaces. Major advances are occurring in quantifying the rates and efficiency of space weathering processes through laboratory experimentation.

Keller, L. P.

2013-01-01

29

The durability of rocks--Developing a test of rock resistance to chemical weathering  

Microsoft Academic Search

Dissolution rates of 39 rock-forming minerals were determined at 20 °C and 100 °C and different pH values, using experimental set-ups which achieve near-zero cation concentrations. Weathering rates in nature for rock above surface were estimated from data in this study and data in the literature. Extraction in a Soxhlet extractor with boiling 2.5 m acetic acid causes an acceleration

WALTER A. FRANKE

2009-01-01

30

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

Microsoft Academic Search

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

Day

1994-01-01

31

Weathering grade of rock masses as a predisposing factor to slope instabilities: Reconnaissance and control procedures  

Microsoft Academic Search

Weathering of rock masses often assumes importance as a predisposing factor to slope instability and it is possible to map it at various scales depending on the different purposes. The effects of weathering processes are particularly intense on crystalline rocks (plutonic and metamorphic). These rocks are present in large areas of the globe and widespread in Calabria. The relationships between

L. Borrelli; R. Greco; G. Gullà

2007-01-01

32

Weathering of rock art at two sites in the KwaZulu-Natal Drakensberg, southern Africa  

Microsoft Academic Search

Sediments of the Karoo Basin in southern Africa represent one of the world's finest laboratories for investigating sandstone weathering. The natural breakdown of these sandstones, most notably in the Clarens Formation, is destroying much of the indigenous rock art heritage that exists there. In an attempt to elucidate the operative weathering processes, a range of micro-climatic, rock temperature, rock moisture,

K. I. Meiklejohn; K. Hall; J. K. Davis

2009-01-01

33

Lithologic Composition and Rock Weathering Potential of Forested, Glacial-Till Soils.  

National Technical Information Service (NTIS)

The document describes methods for predicting lithologies present in soils developed on glacial till, and the potential weathering contributions from rock particles >2 mm in diameter. The methods are not quantitative in terms of providing weathering rates...

S. W. Bailey J. W. Hornbeck

1992-01-01

34

Investigating sedimentary rock deposition and weathering in Mawikwe Bay Sea Caves  

NSDL National Science Digital Library

A field investigation to the Mawikwe Bay Sea Caves of northern Wisconsin along Lake Superior in the winter. Students will investigate deposition of sedimentary rocks and weathering of the rocks to produce sea caves.

35

Chemical Weathering at Rock Art Sites in Western Norway: Which Mechanisms are Active and how can they be Retarded?  

Microsoft Academic Search

Petrographic study of rock samples from 10 western Norwegian rock art sites shows that chemical weathering of the rock surfaces is due to a limited number of mineral dissolution reactions. When the rock art is located on phyllites, weathering is predominantly a result of chlorite and carbonate dissolution plus minor dissolution of apatite and garnet. Weathering of feldspathic metasandstones is

O. Walderhaug

1998-01-01

36

Rock weathering processes and landform development in the Sør Rondane Mountains, Antarctica  

NASA Astrophysics Data System (ADS)

Field observations of weathering processes and the related landforms, combined with laboratory analyses of weathering products, permit a synthetic evaluation of Late Cenozoic weathering environments in the Sør Rondane Mountains, Antarctica, an arid upland characterized by low temperatures and strong winds. Rates and character of weathering depend mainly on moisture availability and the bedrock geology. Under the humid weathering regime that occurs only locally around the margin of the present sheet, frequent diurnal freeze-thaw cycles in summer cause relatively rapid rock fragmentation. Most of the mountains are situated in the arid weathering regime, under which rock breakdown is very slow unless the rock contains plenty of salts. Salt weathering becomes more intensive and extensive with exposure age, as a result of salt accumulation in rock, eventually producing soils as small as fine-silt size. Lack of clay mineralization even in weathered rocks having been exposed above the ice sheet prior to 4 Ma ago indicates that hydrolysis or carbonation of rock minerals has been insignificant during the past 4 Ma. The final products of weathering are due mainly to salt action and reflect the parent lithology. Resistant fine-grained granite forms strongly oxidized tors carved with tafoni, or fields of mushroom-like boulders overlying the fractured bedrock. Less resistant rocks, like biotite gneiss and amphibolite, produce stone pavements underlain by saline, silty soils up to 30-40 cm thick, the thickness of which corresponds to the maximum thaw depth.

Matsuoka, Norikazu

1995-07-01

37

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

ERIC Educational Resources Information Center

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)

Boyer, Robert E.

38

The effect of temperature on experimental and natural chemical weathering rates of granitoid rocks  

Microsoft Academic Search

The effects of climatic temperature variations (5–35°C) on chemical weathering are investigated both experimentally using flow-through columns containing fresh and weathered granitoid rocks and for natural granitoid weathering in watersheds based on annual solute discharge. Although experimental Na and Si effluent concentrations are significantly higher in the fresh relative to the weathered granitoids, the proportional increases in concentration with increasing

Art F. White; Alex E. Blum; Thomas D. Bullen; Davison V. Vivit; Marjorie Schulz; John Fitzpatrick

1999-01-01

39

Weathering grade of rock masses as a predisposing factor to slope instabilities: Reconnaissance and control procedures  

NASA Astrophysics Data System (ADS)

Weathering of rock masses often assumes importance as a predisposing factor to slope instability and it is possible to map it at various scales depending on the different purposes. The effects of weathering processes are particularly intense on crystalline rocks (plutonic and metamorphic). These rocks are present in large areas of the globe and widespread in Calabria. The relationships between rock mass weathering grades and slope instabilities are analysed, with reference to sectors (1:50,000 scale) and areas (1:10,000 scale) where crystalline rocks are strongly affected by weathering. To this aim a reconnaissance procedure has been proposed to delimitate the zones with different weathering condition, three macro-classes at average scale (1:50,000) and six classes at detail scale (1:10,000). In this procedure first analysis of aerial photos and then field observations of representative situations have been used. The reconnaissance procedure has been verified in a selected study area (Acri), whose geological features are provided, by the comparison with weathering maps obtained by means of a control procedure. This last procedure consists of observations and index tests carried out in check points located in representative check sites (discolouration, sound when struck by geological hammer, effect of the point of geological pick, breaking with the hands, rebound of Schmidt Hammer, grain-size analysis). The results obtained confirm through quantitative data that the weathering of a rock mass can be assumed as a predisposing factor to slope instability. At average scale (1:50,000) the reconnaissance procedure is able to give weathering maps representative for this type of evaluation (the ratio between the landslides area in each weathering macro-class and the whole landslide area goes from 67% to 14% for the macro-class A and from 24% to 9% for the macro-class B); at detail scale (1:10,000) it is necessary to use a control procedure to obtain weathering maps indicative of predisposition to slope instabilities.

Borrelli, L.; Greco, R.; Gullà, G.

2007-06-01

40

An Examination of the Space Weathering Patina of Lunar Rock 76015  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

41

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

Microsoft Academic Search

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

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

2009-01-01

42

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

Microsoft Academic Search

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 150years 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

L. Mol; H. A. Viles

2010-01-01

43

Magnetic properties of rivers sands and rocks from Martinique Island: tracers of weathering?  

Microsoft Academic Search

The purpose of this study is to compare the magnetic properties of parent rocks with their weathering products (i.e., sands) in order to ultimately trace the transport pathways of magnetic particles into the ocean. Considering the high rate of alteration and the high magnetic content of volcanic rocks, we chose to study a volcanic island as a test area. We

Anne-Lise Salomé; Laure Meynadier

2004-01-01

44

Using Neutron Scattering to Understand How Porosity opens in Weathering Rocks to Form Regolith  

NASA Astrophysics Data System (ADS)

At the Earth's surface, bedrock formed at high temperature and pressure re-equilibrates to surficial conditions. During this equilibration, a mantle of disaggregated rock known as regolith forms due to interactions between minerals, water, biota, organic matter, and gas. To understand the initial stages of regolith formation, we are making observations showing how pores open and become connected in low porosity rocks during weathering. Pores ranging in size from nanometers to microns are probed using neutron scattering to investigate the mineral - pore interface. For example, we have used neutron scattering to analyze the interface between unweathered and weathered shale, andesite, diabase, and granite. Scattering intensity increases with extent of weathering as the porosity and surface area increases. The interface inside rocks that scatters neutrons can sometimes be characterized as a mass fractal while in other cases the interface is a surface fractal. Furthermore, in basaltic and granitic material, scattering occurs from both, i.e., from pores (mass fractal) and bumps on pore surfaces (surface fractal). In contrast, in scattering from shale, only one fractal is observed. The fractal dimensions also vary with the extent of weathering. For example, in several cases we have observed that weathering causes the mass fractal to transform to a surface fractal as pores become interconnected. We also hypothesize that surface fractal dimensions may decrease when weathering reactions are transport-limited. As we use neutrons to explore the interface of pores inside rocks during weathering, we hope to develop models for predicting these processes quantitatively.

Brantley, S. L.; Bazilevskaya, E.; Jin, L.; Rother, G.; Cole, D. R.; Sitchler, A.; Gu, X.

2012-12-01

45

Rock weathering on the eastern mountains of southern Africa: Review and insights from case studies  

NASA Astrophysics Data System (ADS)

The mountains in the eastern region of southern Africa are of significant regional importance, providing for a diverse range of land use including conservation, tourism and subsistence agriculture. The higher regions are comprised of flood basalts and are immediately underlain by predominantly aeolian-origin sandstones. Our understanding of the weathering of these basalts and sandstones is reviewed here, with particular focus on the insights gained from the Lesotho Highlands Water Project and an ongoing study into the deterioration of rock art. While the chemical weathering attributes of the basalts have been substantially investigated, it is evident that the environmental surface conditions of rock moisture and temperature, as affecting weathering processes, remain largely unknown. Within the sandstones, studies pertaining to rock art deterioration present insights into the potential surface weathering processes and highlight the need for detailed field monitoring. Outside of these site-specific studies, however, little is understood of how weathering impacts on landscape development; notably absent, are detail on weathering rates, and potential effects of biological weathering. Some palaeoenvironmental inferences have also been made from weathering products, both within the basalts and the sandstones, but aspects of these remain controversial and further detailed research can still be undertaken.

Sumner, P. D.; Hall, K. J.; van Rooy, J. L.; Meiklejohn, K. I.

2009-12-01

46

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)

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.

Mol, L.; Viles, H. A.

2010-06-01

47

Cracks in desert pavement rocks: Further insights into mechanical weathering by directional insolation  

NASA Astrophysics Data System (ADS)

The formation of cracks is a fundamental first step in the physical weathering of rocks in desert environments. In this study we combine new field data from the Mojave (U.S.), Gobi (Mongolia) and Strzelecki (Australia) deserts that collectively support the hypothesis that meridional cracks (cracks with orientations not readily attributable to rock anisotropies or shape) in boulders or cobbles form due to tensile stresses caused by directional heating and cooling during the sun's daily transit. The new studies indicate that rock size, surface age, and latitude play important roles with respect to their influence on rock fracture. Rock size and pavement surface age exert an influence on the development of rock cracks as the average clast size of mature desert pavements may be at or below the threshold-clast size for thermal cracking of rocks. Latitude-controlled seasonal temperature variations play a key role, as demonstrated by: 1) tightly clustered mean resultant orientations that differ by latitude, as predicted in McFadden et al. (2005), and 2) very cold wintertime temperatures and strong diurnal gradients that may favor crack development in wintertime, given the likelihood for strong clast heating during early morning hours. The consistent evidence for meridional cracks in surfaces of diverse age and desert environments, climate, vegetation, and distance of clast transport indicate that directional insolation may play the key role in initially generating and propagating rock fractures, rather than a secondary role as implied in recent field and modeling studies of physical weathering in deserts.

Eppes, Martha Cary; McFadden, Leslie D.; Wegmann, Karl W.; Scuderi, Louis A.

2010-11-01

48

Rock cities, periglacial mass-wasting, and honeycomb weathering in Warren County, northwestern Pennsylvania  

SciTech Connect

Imposing hilltop rock-cities developed from widely jointed outcrops of Olean conglomerate (Lower Pennsylvanian) create picturesque scenery on the Allegheny High Plateau in Warren Co., Pa. At least six such rock cities 2 to 5 acres in extent are associated with the Late Wisconsinan glacial border in the northern half of the county. Farther to the south, jumbled Olean and Knapp (Lower Mississippian) joint blocks occur on steep slopes below valley-wall cliffs. The rock cities and accumulations of displaced joint blocks are largely relics of Late Wisconsinan periglacial mass-wasting. Frost splitting initiated opening of bedrock joints to form buildings. Gravity, soil wedging, and possibly gelifluction then widened the fissures into streets. Gelifluction moved blocks downslope and oriented their long axes parallel with slope (Warren Rocks). Forward toppling of high, unstable blocks contributed to mass-movement on some steep slopes (Rimrock). Today, rock cities and downslope blocks are stable in areas of gentle (less than 10 percent) slopes, but toppling, solifluction, creep, and debris flows cause continued slow movement of large blocks on moderately steep to steep (greater than 30 percent) slopes. Blocks of Olean and Knapp conglomerate have both stratabound pitting and intricate honeycomb weathering. Deep pitting is controlled largely by variations in silica cementation. Honeycomb weathering is most evident in sandy layers and results from patterns of iron-oxide impregnation. Both are Holocene surface-weathering processes.

Inners, J.D.; Sevon, W.D.; Moore, M.E. (Pennsylvania Geological Survey, Harrisburg, PA (United States)); Berg, T.M. (Ohio Division of Geological Survey, Columbus, OH (United States))

1993-03-01

49

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

50

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

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

51

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

NASA Technical Reports Server (NTRS)

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.

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

52

Rocks  

NSDL National Science Digital Library

This guide explores rocks, from processes that can change them (such as weathering), to what can happen to them as they move through the rock cycle. Using this guide, teachers of middle school students will focus on the tangible process of sedimentary roc

National Science Teachers Association (NSTA)

2009-07-01

53

Microstructural weathering of sedimentary rocks by freeze–thaw cycles: Experimental study of state and transfer parameters  

Microsoft Academic Search

The frost sensitivity of a rock is resulting from the combined action of processes linked to porous network characteristics (state parameters) and to the way water flows into this porous network (transfer parameters), our study was thus about the influence of these parameters on frost weathering of rocks. Sedimentary rocks often found on buildings (limestone and sandstone) and consequently submitted

Alice Saad; Sylvine Guédon; François Martineau

2010-01-01

54

Microbial Populations and Activities in the Rhizoplane of Rock-Weathering Desert Plants. II. Growth Promotion of Cactus Seedlings  

Microsoft Academic Search

AWmct= Four bacterial species isolated from the rhizoplane of cadi growing in bare lava rocks were assessed for growth pro- motion of giant cardon cactus seedlings (Pachyceneus pringlei), These bacteria fixed N2, dissolved P, weathered extrusive igne- ous rock, marble, and limestone, and significantly mobilized useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn in rock min-

M. E. Puentel; C. Y. Li; Y. Bashan

2004-01-01

55

Weather  

NSDL National Science Digital Library

This is a first grade weather unit. SEASONS Fall Winter Build a Snowman Spring Summer What things determine and effect the weather? Cloud Precipitation Sunshine Temperature Visibility Wind Direction Wind Force WEATHER VIDEOS Tornado Hurricane Hail Lightning FUN AND GAMES Dress the Bear for the Weather The Great Weather Race Game Weather coloring books for kids ...

Stearns, Ms.

2008-10-25

56

The role of disseminated calcite in the chemical weathering of granitoid rocks  

USGS Publications Warehouse

Accessory calcite, present at concentrations between 300 and 3000 mg kg-1, occurs in fresh granitoid rocks sampled from the Merced watershed in Yosemite National Park, CA, USA; Loch Vale in Rocky Mountain National Park CO USA; the Panola watershed, GA USA; and the Rio Icacos, Puerto Rico. Calcite occurs as fillings in microfractures, as disseminated grains within the silicate matrix, and as replacement of calcic cores in plagioclase. Flow-through column experiments, using de-ionized water saturated with 0.05 atm. CO2, produced effluents from the fresh granitoid rocks that were dominated by Ca and bicarbonate and thermodynamically saturated with calcite. During reactions up to 1.7 yr, calcite dissolution progressively decreased and was superceded by steady state dissolution of silicates, principally biotite. Mass balance calculations indicate that most calcite had been removed during this time and accounted for 57-98% of the total Ca released from these rocks. Experimental effluents from surfically weathered granitoids from the same watersheds were consistently dominated by silicate dissolution. The lack of excess Ca and alkalinity indicated that calcite had been previously removed by natural weathering. The extent of Ca enrichment in watershed discharge fluxes corresponds to the amounts of calcite exposed in granitoid rocks. High Ca/Na ratios relative to plagioclase stoichiometries indicate excess Ca in the Yosemite, Loch Vale, and other alpine watersheds in the Sierra Nevada and Rocky Mountains of the western United States. This Ca enrichment correlates with strong preferential weathering of calcite relative to plagioclase in exfoliated granitoids in glaciated terrains. In contrast, Ca/Na flux ratios are comparable to or less than the Ca/Na ratios for plagioclase in the subtropical Panola and tropical Rio Icacos watersheds, in which deeply weathered regoliths exhibit concurrent losses of calcite and much larger masses of plagioclase during transport-limited weathering. These results indicate that the weathering of accessory calcite may strongly influence Ca and alkalinity fluxes from silicate rocks during and following periods of glaciation and tectonism but is much less important for older stable geomorphic surfaces.

White, A. F.; Bullen, T. D.; Vivit, D. V.; Schulz, M. S.; Clow, D. W.

1999-01-01

57

Weather  

NSDL National Science Digital Library

Have you ever wondered how the weather man, or meteorolgist, on TV knows what to say about tomorrow\\'s weather? It\\'s because they have certain tools that they use that help them predict what the weather will be. Throughout this school year you are going to be making tools and predicting weather just like a meterorologist! Task You are going to be weather forcasters! You are going to record and track weather patterns throughout the year. You will also use weather tools to make predictions about the weather like real weather forecasters! The Process 1. First we need to learn a little bit about weather so ...

Williams, Ms.

2005-10-25

58

Climatic controls on mechanical rock strength and channel incision due to bedrock weathering, Kohala Peninsula, Hawaii  

NASA Astrophysics Data System (ADS)

Orographic precipitation gradients are prevalent in mountainous terrains, and climate-dependent bedrock weathering may play an important role in the incision of bedrock channels and the evolution of landscapes. Kohala Peninsula on the big island of Hawaii presents a unique natural setting for exploring climate sensitivity of landscape erosion, with over an order of magnitude variation in mean annual precipitation, a landscape composed entirely of weatherable basalt, and systematic variations in fluvial incision and resulting topography across the climate gradient. We hypothesize that increases in local mean annual precipitation will promote long-term channel incision rates due to increases in bedrock weathering, but measurements of rock strength within bedrock channels will be greatly influenced by the efficient removal of weathered rock by fluvial erosion. Mechanical properties of bedrock were measured at a total of 13 sites across two watersheds that vary in local mean annual precipitation from 0.27 - 2.25 m/yr. In situ strength measurements were collected using a Schmidt hammer with a pseudo-random sampling method along transects parallel to stream direction and just above the channel thalweg. Tensile strength and elastic moduli were also measured in the laboratory on cores collected from a subset of the same transects. Long-term channel incision rates were independently constrained from the local valley relief and the ages of mapped basalt units that form the relatively unmodified volcanic shield of Kohala. When strength data comes from sites of low long-term incision, we find strong power-law relationships between both rock strength measurements and local mean annual precipitation. However, for sites with high precipitation rate and variable erosion rates, we find significant variability in the rock strength. We interpret this to reflect the removal of weathered rock by erosion. In order to interpret the influence of climate in our dataset, we made a normalized "climate-incision index" by dividing local precipitation rate (m/yr) by the local erosion rate (m/yr). When rock strength is plotted against this climate-incision index the data nicely collapses into consistent power-law relationships. Therefore, by removing the influence of local long-term incision from the data, the relationship between decreasing rock strength and increasing local mean annual precipitation becomes clear. Identifying this relationship may help explain the varied patterns of incision observed across the Kohala peninsula. Finally, if changes in mechanical rock strength are representative of weathering patterns across the landscape, this result may also suggest an influence on other key fluvial characteristics, such as sediment supply in channels. While Kohala may be an ideal site to isolate these trends, influences of bedrock weathering may be important for landscape evolution across many other orographic precipitation gradients.

Murphy, B. P.; Johnson, J. P.; Gasparini, N. M.; Sklar, L. S.

2013-12-01

59

Geochemical evolution of solutions derived from experimental weathering of sulfide-bearing rocks  

USGS Publications Warehouse

The chemical composition of natural waters is affected by the weathering of geologic materials at or near the surface of the Earth. Laboratory weathering experiments of whole-rock sulfide rocks from the Shoe-Basin Mine (SBM) and the Pennsylvania Mine (PM) from the Peru Creek Basin, Summit County, Colorado, indicate that the mineral composition of the sulfide rocks, changes in pH, the duration of the experiment, and the formation of sorbents such as Fe and Al oxyhydroxides affect the chemical composition of the resulting solution. Carbonate minerals in the rock from SBM provide buffering capacity to the solution, contribute to increases in the pH and enhance the formation of Fe and Al oxyhydroxides, which sorb cations from solution. The final solution pH obtained in the experiments was similar to those measured in the field (i.e., 2.8 for PM and 5.0 for SBM). At PM, acidic, metal-rich mine effluent is discharged into Peru Creek where it mixes with stream water. As a result, the pH of the effluent increases causing Fe and Al oxyhydroxide and schwertmannite to precipitate. The resulting solids sorb metal cations from the water thereby improving the quality of the water in Peru Creek. ?? 2006.

Munk, L.; Faure, G.; Koski, R.

2006-01-01

60

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

NASA Astrophysics Data System (ADS)

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

Presler, J. K.

2012-12-01

61

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

62

Ultramafic rock weathering and slope erosion processes in a South West Pacific tropical environment  

NASA Astrophysics Data System (ADS)

Weathering and erosion processes are investigated using electrical resistivity tomography (ERT) imaging and the quantification of geomorphic patterns at the edges of a lateritic plateau overlying ultramafic rocks in the north western region of the main island of New Caledonia (Southwest Pacific). The obtained ERT images document the structure and long-term evolution of the regolith, while source area parameters such as area ( A) local slope above channel head (tan ?) and longitudinal river profiles allow the characterization of contrasting geomorphic patterns around the plateau. The geo-electrical profiles show a succession of hard rock protrusions and weathering troughs, whose depth varies greatly. The area-slope relationship allows the distinction between saprolite- and ferricrete-mantled source areas. The former could result from a regolith erosion process by shallow landslides; the latter from a secondary ferruginization process of reworked lateritic debris. The deepest troughs underlie saprolite-mantled source areas above channel heads, which are characterized by a low permeability saprolite, relatively high slope gradient, and lower area/slope ratios. Such source areas generate fairly high runoff, sustaining rivers and creeks with relatively high erosion power. The ferricrete-mantled source areas are characterized by higher permeability and area/slope ratios, leading to lower runoff and less erosion but further chemical rock weathering. The ferricrete of those source areas acts as a protective hardcover against mechanical erosion of the underlying regolith. This ferricrete reworks, at least partly, allochtonous lateritic materials inherited from a previous disaggregated ferricrete that suggests past erosion processes driven by hydro-climatic condition changes.

Beauvais, Anicet; Parisot, Jean-Claude; Savin, Cécile

2007-01-01

63

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

PubMed Central

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 ?m) 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.

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

1979-01-01

64

Weather  

NSDL National Science Digital Library

The National Oceanic and Atmospheric Administration (NOAA) provides these two Websites on weather. The first site serves as a major hub for information related to weather, with links to primary data sources, forecasts, maps, images (such as the latest satellite imagery for North America), and a wealth of other data, including space weather. Researchers will also find links to national weather research centers and other related agencies.

65

Weather  

NSDL National Science Digital Library

What are the different types of weather? In this project you will compare different types of weather by drawing pictures and making it into a flip book. First you will begin by learning about the different types of weather. Read about each topic. Then get together with your partner and draw a picture of each type of weather. 1. Thunder storm Thunder storm Thunder storm Kids 2. Lightning Lightning Lightning picture 3. Tornado Tornadoes Tornado Kids 4. ...

Jennie, Miss

2009-10-22

66

Solar-induced weathering of rocks: integrating instrumental and numerical studies  

NASA Astrophysics Data System (ADS)

The contribution of solar-driven thermal cycling to the progressive breakdown of surface rocks on the Earth and other planets is controversial. We introduce a current study of the physical state in boulders that integrates modern instrumental and numerical approaches to quantify the surface temperature, stresses, strains, and microfracture activity in exposed boulders, and to shed light on the processes underlying this form of mechanical weathering. We are monitoring the surface and environmental conditions of two ~30 cm dia. granite boulders (one in North Carolina, one in New Mexico) in the field for ~1 yr each. Each rock is instrumented with 8 thermocouples, 8 strain gauges, a surface moisture sensor and 6 Acoustic Emission (AE) sensors to monitor microfracture activity continuously. These sensors and a full meteorological station, including soil-moisture probes, are combined into a single, remotely accessible system. AE events can be located to within 2.5 cm. We are able 1) to spatially and temporally correlate microcrack growth (AE events) with the rock surface and environmental conditions experienced by the rock, and 2) to validate modeling results. The modeling work addresses two coupled problems: 1) the time-varying thermal regime of rocks exposed to diurnal variations in solar radiation as dictated by latitude, and time of the year, as well as the surface emissivity and thermal properties of the rock and soil, and size and shape of the rock, and 2) the corresponding time-varying stress and strain fields in the rocks using representative elastic properties and realistic rock shape and orientation. AE events tend to occur shortly after sunset (6-9 pm) in the upper portion of the boulder. Most of the events occur in summer and winter months for the NC boulder. The majority occur in bursts of tens to hundreds over periods of a few minutes, and are often associated with environmental factors other than simple diurnal warming and cooling, such as wind gusts, that result in rapid rock surface temperature changes. Numerical results illuminate the evolution of thermal stresses, their relation to the direction of solar radiation, and their strong non-linear dependence on the size of the rocks. Because thermal tensile stresses decrease with size for rocks smaller than about 1 m-dia., we expect solar exposure to be effective in breaking down boulders and cobbles, while having little impact on gravel size and smaller clasts. This leads to a fining of the size distribution of surface clasts in deserts, and contributes to desert pavement formation. Our quantitative experimental and modeling studies document a direct link between rock cracking and stresses associated with the thermal conditions arising from natural diurnal change. This approach holds considerable promise for advancing research on this theme with diverse potential applications including the deterioration of man-made structures, monuments and sculptures, and breakdown of surface rocks or bedrock on other planets.

Hallet, B.; Eppes, M. C.; Mackenzie-Helnwein, P.; Warren, K.; McFadden, L.; Gillespie, A.; Putkonen, J.; Swami, S.; Shi, J.

2011-12-01

67

Niobium, tantalum, zirconium, and hafnium in the crusts of weathering of trans-angara alkaline rock mass (yenisei mountain country)  

SciTech Connect

The distribution of Nb, Ta, Zr, and Hf in the crusts of weathering of foyaites and their microclinized and albitized varieties - ijolites and pegmatites - is investigated. The contents of these elements in the specimens were determined by neutron activation and x-ray radiometry. The distributions of the elements in the weathering profiles were studied by isovolumetric techniques. It has been determined that the behavior of the rare elements during the weathering is largely determined by the mineral forms in which they occur in the original rocks and also by the composition of the products of hypergenetic alteration of these rocks. It is shown that the clay matter of weathering is an efficient accumulator of the rare elements being studied.

Tsibul'chik, V.M.; Shipitsyn, Y.G.; Solotchina, E.P.

1986-09-01

68

The effect of temperature on experimental and natural chemical weathering rates of granitoid rocks  

USGS Publications Warehouse

The effects of climatic temperature variations (5-35??C) on chemical weathering are investigated both experimentally using flow-through columns containing fresh and weathered granitoid rocks and for natural granitoid weathering in watersheds based on annual solute discharge. Although experimental Na and Si effluent concentrations are significantly higher in the fresh relative to the weathered granitoids, the proportional increases in concentration with increasing temperature are similar. Si and Na exhibit comparable average apparent activation energies (E(a)) of 56 and 61 kJ/mol, respectively, which are similar to those reported for experimental feldspar dissolution measured over larger temperature ranges. A coupled temperature-precipitation model, using an expanded database for solute discharge fluxes from a global distribution of 86 granitoid watersheds, produces an apparent activation energy for Si (51 kJ/mol), which is also comparable to those derived from the experimental study. This correlation reinforces evidence that temperature does significantly impact natural silicate weathering rates. Effluent K concentrations in the column study are elevated with respect to other cations compared to watershed discharge due to the rapid oxidation/dissolution of biotite. K concentrations are less sensitive to temperature, resulting in a lower average E(a) value (27 kJ/mol) indicative of K loss from lower energy interlayer sites in biotite. At lower temperatures, initial cation release from biotite is significantly faster than cation release from plagioclase. This agrees with reported higher K/Na ratios in cold glacial watersheds relative to warmer temperate environments. Increased release of less radiogenic Sr from plagioclase relative to biotite at increasing temperature produces corresponding decreases in 87Sr/86Sr ratios in the column effluents. A simple mixing calculation using effluent K/Na ratios, Sr concentrations and 87Sr/86Sr ratios for biotite and plagioclase approximates stoichiometric cation ratios from biotite/plagioclase dissolution at warmer temperatures (35??C), but progressively overestimates the relative proportion of biotite with decreasing temperature. Ca, Mg, and Sr concentrations closely correlate, exhibit no consistent trends with temperature, and are controlled by trace amounts of calcite or exchange within weathered biotite. The inability of the watershed model to differentiate a climate signal for such species correlates with the lower temperature dependence observed in the experimental studies.

White, A. F.; Blum, A. E.; Bullen, T. D.; Vivit, D. V.; Schulz, M.; Fitzpatrick, J.

1999-01-01

69

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

NASA Astrophysics Data System (ADS)

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 cavities in MP, others question whether differential weathering (either aqueous or physical) of softer sulfide (troilite) nodules or other inclusions such as schreibersite [5] in the metal matrix may be at least partly responsible. A discontinuous coating of darker material, interpreted to be oxide (though it is uncertain whether this is relict fusion crust or weathering rind), appears in the MI images also to have been polished and sculpted by abrasive forces. Laboratory experiments designed to address the requirements for iron shaping by wind abrasion would help provide constraints on the wind velocities involved in these processes. Preliminary results for Block Island display many features that are also consistent with aeolian abrasion. References: [1] Schröder C. et al. (2008) JGR 113, E06S22, doi:10.1029/2007JE002990. [2] Ashley J. W. et al. (2009) LPSC XL. [3] Schröder C. et al. (2009) LPSC XL. [4] Connolly H.C.J. et al. (2006) Meteoritical Bulletin #90, Meteoritics and Planet Sci. 41(9): p. 1383-1418. [5] Fleischer I. et al. (2009) Meteoritics and Planet Sci. 44, p. A70.

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

2009-12-01

70

Weather  

NSDL National Science Digital Library

You will learn how to describe and observe changes in weather patterns by completing the following activities. The students will record and report changes in weather on their data sheet. The Process: Read the information on How Air Pressure Affects You. In this article you will see the term barometer. Write its definition. Now look over Weather Facts. Now go to Investigate Climate Conditions and use the weather maker to observe the effects of certain changes. Answer the questions: How much of a change in temperature is needed to make it ...

Lauren, Ms.

2010-11-17

71

Bacterially Induced Weathering of Ultramafic Rock and Its Implications for Phytoextraction  

PubMed Central

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.

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

2013-01-01

72

Bacterially induced weathering of ultramafic rock and its implications for phytoextraction.  

PubMed

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

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

2013-09-01

73

Excavatability Assessment of Weathered Sedimentary Rock Mass Using Seismic Velocity Method  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

74

Weathering of chrysotile asbestos by the serpentine rock-inhabiting fungus Verticillium leptobactrum.  

PubMed

Verticillium leptobactrum, a rare fungal species, has repeatedly been isolated from serpentinic rocks in the Western Alps, thus suggesting that it adapts easily to this selective mineral substrate. The rRNA internal transcribed spacer region of several isolates has been sequenced to confirm their identity and taxonomic position within Verticillium, a recently revised polyphyletic entity. Isolates of V. leptobactrum have also been investigated to establish their ability to weather asbestos chrysotile, the most common mineral in the isolation sites. The results of solubilization assays on magnesium and silicon, as well as measurement of the Mg/Si ratio in the asbestos fibres after exposure to fungal mycelia, indicate a high bioweathering activity of V. leptobactrum towards chrysotile. Comparison with data on Fusarium oxysporum shows differences among species, with V. leptobactrum being more active than F. oxysporum in removing structural ions from chrysotile. Asbestos weathering by fungi could be envisaged as a bioremediation strategy for hazardous asbestos-rich soils (e.g. abandoned mines). Fungi that have adapted to live in serpentine sites could be good candidates for this purpose. PMID:19453742

Daghino, Stefania; Turci, Francesco; Tomatis, Maura; Girlanda, Mariangela; Fubini, Bice; Perotto, Silvia

2009-07-01

75

Subduction of Serpentinized and Weathered Ultramafic Rocks in the Puerto Rico Trench: Preliminary Results  

NASA Astrophysics Data System (ADS)

Exposure of mantle peridotite and its interactions with seawater to form serpentinite are integral parts of seafloor spreading, and play a key role in affecting the rheology, chemistry, and microbial habitability of the oceanic lithosphere at slow- and ultra-slow spreading ridges. Away from the spreading centers, within subduction zones, the formation and dehydration of serpentinized peridotite impacts seismicity, element cycling, and melt generation. Here we present preliminary results of a petrographic and spectroscopic study of altered rocks recovered from the from the north wall of the trench Puerto Rico Trench (PRT). In fact, the PRT represents one of two subduction zones worldwide where slow spreading oceanic lithosphere is presently subducted, and where serpentinized peridotite has been directly evidenced by seafloor sampling {Bowin, 1966}. Thin section petrography, XRF analysis, scanning electron microscopy, and confocal Raman spectroscopy reveal that the peridotite, which in all likelihood originated at the Mid-Atlantic Ridge during the early Cretaceous, was virtually completely serpentinized under static conditions (as it is evidenced by the preserved mesh texture after olivine and bastite after orthopyroxene), and underwent subsequent seafloor weathering. While it is questionable where exactly serpentinization and subsequent seafloor weathering took place, our preliminary results strongly suggest that the material presently subducted in the PRT is not simply composed of serpentine, magnetite, and brucite; it is rather a complex disequilibrium assemblage of minerals including serpentine, brucite, chlorite, talc, magnetite, hematite, goethite, sulfur-rich sulfides and various clay minerals. Furthermore, our results imply that serpentinite and its weathering products influence the loci of dehydration and mineral replacement reactions, as well as the water input and element recycling in subduction zones.

Horning, G.; Klein, F.

2012-12-01

76

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

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

77

Air temperature-driven CO2 consumption by rock weathering at short timescales: Evidence from a Holocene lake sediment record  

NASA Astrophysics Data System (ADS)

The role that air temperature plays in the interaction between atmospheric CO2 levels and continental rock weathering at relatively short time scales is still a matter of debate. Laboratory studies reveal a strong dependence of mineral dissolution on temperature, but field comparisons among watersheds under different climate conditions often indicate correlations with other environmental factors. Using a paleolimnological approach, here we show that there has been an extremely good coupling between rock weathering, water alkalinity (CO2 consumption), and air temperature during the last 10,000 years at sub-millennial time scales in a small watershed of silicate bedrock and scarce vegetation. The calculation of apparent activation energy for the weathering reaction (as a means to describe the temperature dependence of the process) provides a value (Ea = 67 ± 7 kJ mol-1) that is comparable to those found for silicate rocks similar to those in the watershed in laboratory experiments and some field studies. Our results provide evidence that regulatory constraints between air temperature, atmospheric CO2 and silicate rock weathering can be fine-tuned at geological timescales and may not be negligible in the current context of global change.

Catalan, Jordi; Pla-Rabés, Sergi; García, Joan; Camarero, Lluís

2014-07-01

78

Chemical weathering on Mars thermodynamic stabilities of primary minerals (and their alteration products) from mafic igneous rocks  

Microsoft Academic Search

Chemical weathering on Mars is examined theoretically from the standpoint of heterogeneous equilibrium between solid mineral phases and gaseous 02, H20, and CO2 in the Martian atmo- sphere. Thermochemical calculations are performed in order to identify important gas-solid decomposition reactions involving the major mineral constituents of mafic igneous rocks. Where unavailable in the thermochemical literature, Gibbs free energy and enthalpy

JAMES L. GOODING

1978-01-01

79

Weather.  

ERIC Educational Resources Information Center

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)

Web Feet K-8, 2000

2000-01-01

80

Weathering  

Microsoft Academic Search

In the natural environment, weathering and breakdown of stone is an accepted part of long-term landscape development but the\\u000a same acceptance of change and deterioration is not extended to stone used in construction especially when such deterioration\\u000a affects historically and\\/or culturally important structures. The value of an integrative approach to improve understanding\\u000a of weathering and failure of building stone is

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

81

Role of fractures in weathering of solid rocks: narrowing the gap between laboratory and field weathering rates  

NASA Astrophysics Data System (ADS)

A weathering study of a fractured environment composed of granites and metasediments was conducted in Trás-os-Montes and Alto Douro (north of Portugal) and covered the hydrographic basin of Sordo river. Within the basin, a number of perennial springs were monitored for discharge rate, which allowed for the estimation of annual recharges. A small area of the basin was characterized for parameters such as hydraulic conductivity and effective porosity, which, in combination with the previously calculated recharges, allowed for the calculation of a fracture surface area. The monitored springs were also sampled and analyzed for major inorganic compounds, and using a mole balance model the chemistry of the water samples was explained by weathering to kaolinite of albite-oligoclase plus biotite (granites) or of albite plus chlorite (metasediments). The number of moles of dissolved primary minerals (e.g. albite) could be calculated using this method. These mass transfers were then multiplied by the spring's median discharge rate and divided by the fracture surface area to obtain a weathering rate. Another weathering rate was determined, but using a BET surface area as normalizing factor. Comparing both rates with a representative record of laboratory as well as of field-based weathering rates, it has been noted that rates normalized by the BET were, as expected, similar to commonly reported field-based rates, whereas rates normalized by the fracture surface area were unexpectedly relatively close to laboratory rates (one order of magnitude smaller). The monitored springs are of the fracture artesian type, which means that water emerging at the spring site flowed preferentially through joints and fractures and that weathering took place predominantly at their walls. Consequently, it was concluded that the most realistic weathering rates are those normalized by the fracture surface area, and as a corollary that the gap between laboratory and field weathering rates might not be as wide as usually is reported to be.

Pacheco, Fernando A. L.; Alencoão, Ana M. P.

2006-01-01

82

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

NASA Astrophysics Data System (ADS)

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 calculated the ieq, spring watershed areas and travel times were downscaled using the regression equations (A < 10 km2 and t = 1.4-2.8 year). Standing on the physical and hydrologic parameters of the spring watersheds, the THROW model finally calculates plagioclase weathering rates in the vicinity of the spring sites. The SiB model (Pacheco and Van der Weijden, 1996) was used before to estimate the contribution of plagioclase dissolution to the chemical composition of these springs (Van der Weijden and Pacheco, 2006). The chemical data were now coupled with K, ne and t in a rate equation to estimate chemical weathering rates of plagioclase in the basin. In the THROW model, the rate equation describes the exposed surface area as a function of fracture spacings, openings and porosities (Pacheco and Alencoão, 2006). The calculated rates (WPl = (2.5 ± 1.2) × 10-14 mol m-2 s-1) are consistent with previous reports and with results of experimental kinetic models. The SiB results predict formation of halloysite and gibbsite along the flow path, which were indeed close to equilibrium with the dissolved Al and Si activities.

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

2012-03-01

83

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)

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.

Pillans, Brad; Fifield, L. Keith

2013-06-01

84

Worldwide distribution of continental rock lithology: Implications for the atmospheric\\/soil CO2 uptake by continental weathering and alkalinity river transport to the oceans  

Microsoft Academic Search

The silicate rock weathering followed by the formation of carbonate rocks in the ocean, transfers CO2 from the atmosphere to the lithosphere. This CO2 uptake plays a major role in the regulation of atmospheric CO2 concentrations at the geologic timescale and is mainly controlled by the chemical properties of rocks. This leads us to develop the first world lithological map

Philippe Amiotte Suchet; Jean-Luc Probst; Wolfgang Ludwig

2003-01-01

85

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

SciTech Connect

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.

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

1986-11-01

86

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

NASA Astrophysics Data System (ADS)

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. LiDAR scanning was applied on representative areas (~30-50 m2) of 10 separate surfaces ranging from rough Holocene surfaces to fairly smooth surfaces with well-developed pavements displaying an OSL age of 87 kyr. We find typical and recurring time-dependent changes in the offset as well as shape of the PSD curves in both chronosequences: PSD offset is continuously reduced over time reflecting the overall reduction in the amplitude of roughness at all wavelengths. The PSD curves display progressive moderation of slopes at the longer wavelengths with the moderation point itself systematically shifted to shorter wavelengths. This characteristic evolution of PSD offset and slope moderation at longer wavelengths reflects the typical break up of boulder-sized clasts through time as the surfaces mature into well-developed desert pavements and points towards mechanical breakdown as the dominant weathering mode. In addition, we are able to determine the rate by which the larger clasts are removed from the system. We build on these new insights into process and rate of rock weathering to propose PSD analysis of surface roughness as a complementary method for constraining the age of desert alluvial surfaces in places where 'conventional' dating cannot be applied.

Mushkin, Amit; Sagy, Amir; Trabelci, Eran

2013-04-01

87

Weather  

NSDL National Science Digital Library

In the project you will learn about thunderstorms and tornadoes and play a weather matching game. What exactly are thunderstorms and tornadoes? Use your T- chart to explain some facts about a thunderstorm and a tornado as we review each. T-Chart Begin by reviewing what a thunderstorm is and how they form. Thunderstorm information What is a thunderstorm? What are thunderstorms most likely to occur? What causes thunder? Next review what a tornado ...

Caitlin, Ms.

2009-10-21

88

External Resource: Mechanical Weathering  

NSDL National Science Digital Library

A student activity with teacher's sheet, to give the students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Mechanical weathering is the process of breaking down bedroc

1900-01-01

89

Weathering Animation  

NSDL National Science Digital Library

Weathering is the term that describes all the processes that break down rocks in the environment near the Earth's surface. This module will help you to understand two weathering processes: mechanical and chemical.

2002-01-01

90

Regolith Evolution Influences Element Redistribution During Weathering of Volcanic Rocks in Erosional, Sedentary, and Depositional Landscapes: Examples From Hawai'i, Guatemala and Southeastern Australia  

NASA Astrophysics Data System (ADS)

This study examines the weathering of volcanic rocks exemplifying each of three landscape/regolith associations (erosional, sedentary/relict/residual, and depositional), and illustrates how the regolith/landscape associations and their geomorphic evolution influence the geochemical evolution of the regolith. In erosional landscapes, the rate of physical erosion exceeds the rate of chemical weathering of rock to altered regolith, and surface materials consist of fresh or minimally weathered bedrock. Recent basalts (<4ka) from Hawai'i have weathered slightly and have accumulated no weathering rinds, saprolite, or allochthonous regolith over their brief exposure history. Whole-rock geochemistry is not affected by the small amount of chemical weathering. Leaching has been insufficient for differential removal of elements, and there are no elemental sources outside of the nearly fresh outcrops from which elements might have been introduced into the exposed volumes. In sedentary/relict/residual landscapes, the rate of chemical weathering equals or exceeds the rate of physical erosion, and surface material consists of deeply weathered saprolite. Some volcanic rocks of Plio-Pleistocene age from Hawai'i and Guatemala have experienced spheroidal or corestone weathering, in which corestones of minimally weathered rock are surrounded by concentric saprolitic shells and saprolite derived from the decomposition of the volcanic rock. Many major elements and some minor elements (REE) are depleted from the saprolitic portions of these regoliths. However, several of these minor elements (REE) are enriched in the inner portions of corestone-shell complexes, suggesting that these minor elements and REE leached from saprolite are transferred within the regolith to secondary minerals formed during incipient weathering of the corestones. In depositional landscapes, the surficial material consists of sediment (colluvial, fluvial/alluvial, or aeolian). Tertiary volcanic rocks of the Monaro Volcanic Province (New South Wales, Australia) were emplaced in fluvial-lacustrine environments and almost immediately covered by fine-grained clastic sediment. The jointed flows weathered spheroidally. Corestones have essentially fresh major element and REE signatures. However, Zr (probably redistributed physically from the fine-grained sediment) exhibits systematic absolute enrichment with progressive weathering in the Monaro corestone-shell complexes. Weathering of volcanic rocks results in geochemical trends that differ systematically with the presence, nature, and extent of development of associated regolith. Geochemical patterns of element depletion and enrichment in individual samples and suites of samples can only be properly interpreted if the regolith/landscape context of the samples is taken into account.

Velbel, M. A.; Patino, L. C.; Price, J. R.; Wade, J. A.

2004-12-01

91

Weathering kinetics of waste rock from the Aitik copper mine, Sweden: scale dependent rate factors and pH controls in large column experiments  

Microsoft Academic Search

Geochemical processes in mining waste rock, including sulphide weathering, heavy metal release (Cu and Zn), and acidity consumption by carbonate and silicate mineral weathering have been investigated. We operated six large columns, each containing about 1.6 tons of waste rock, with unsaturated water flow for nearly 3 1\\/2 years. The column results illustrate two pH controls: (1) sulphide oxidation with

B. Strömberg; Steven Banwart

1999-01-01

92

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

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.

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

1985-01-01

93

Rocks  

NSDL National Science Digital Library

This year we are going to learn about rocks. Do you like to collect rocks? Rocks are the most common material on earth. We will learn about the parts that make up the rocks and sort rocks based upon color, hardness, texture, layering, and particle size. So you want to learn about rocks? Go to Intro to Rocks for some fascinating facts about rocks! Now lets learn about some of the different kinds of rocks. Igneous Rocks Metamorphic Rocks Sedimentary Rocks Click here to see the differences between the types of rocks that you have learned about What Type Of Rock Do I Have?. After doing all the activities above, ...

Woodruff, Mrs.

2010-06-21

94

The relative influence of lithology and weathering in shaping shore platforms along the coastline of the Gulf of La Spezia (NW Italy) as revealed by rock strength  

NASA Astrophysics Data System (ADS)

Along the rock coasts of the Gulf of La Spezia, which are characterised by a Mediterranean microtidal environment, a limited number of small rock platforms are scattered, constrained in elevation within 5 m above present-day sea level. This work deals with a number of these rock platforms, formed in different rock types (one in limestone and two in dolomite), that show differences in their morphology. This paper aims to provide a quantitative examination of why there are morphological differences between platforms in this region. To achieve this purpose, factors controlling platform morphology and the processes acting on them are investigated through a comparative analysis of rock strength. Rebound values, obtained testing rock surfaces with the Schmidt hammer, were compared between different platforms and between different sectors of the same platform. Each platform was subdivided into two parts based on visual difference in rock surface colour, characterised by differences in occurrence of weathering microforms and bioerosive agents. Rebound values in the lower part of the platforms proved to be lower than in the upper part, providing quantitative assessment of the occurrence of weathering acting to different extents in the upper and lower part of the shore platforms (weathering degraded rock strength in the lower part by about 15%). It was demonstrated that on the upper part of platforms, displaying moderate evidence of physical and biological weathering, lithology significantly influences the rock strength. On the portion of platforms closer to sea level, instead, differential exposure histories of the same rock type in the same environmental setting can yield statistically significant variations in rock strength values. Thus, it is clear that in the lower part of the investigated platforms, the degree of weathering has strong bearing on rock strength, and that variations in rock strength are not solely due to lithology. According to the results of this work, experimental values of rock strength of platforms in the study area depend both on the rock type and on physical weathering due to frequently repeated wetting and drying and bioerosion. Lithology is then an important factor controlling platform shape and weathering is an important process operating on them.

Chelli, Alessandro; Pappalardo, Marta; Llopis, Isabel Arozarena; Federici, Paolo Roberto

2010-05-01

95

Study of Weathering Velocity of Rocks with Uranium as a Natural Tracer. Application to Two Drainage Basins of the North-East of Brazil.  

National Technical Information Service (NTIS)

A study on rock weathering rate, i.e. rock-soil interface formation, was performed by measuring the elements dissolved in river waters. These elements are used as natural tracers. This work has been carried out in the drainage basin of Preto and Salgado R...

L. M. da Costa Pinto Moreira Nordemann

1977-01-01

96

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

NASA Astrophysics Data System (ADS)

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 rainfall, control the groundwater level and oxygen transport.

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

2008-05-01

97

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

NASA Astrophysics Data System (ADS)

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 correlation with the structural setting of the rock mass and the mineralogical properties of the limestones, an overall weathering study was carried out, by combining surface surveys with analyses of the inner structure. A holistic TLS point cloud of Citadel, produced by Consorzio Ferrara Ricerche of the University of Ferrara and made available by the Restoration Unit, was exploited to perform a 3D quantitative kinematic analysis of the entire rock mass. Each sector was classified in relation to the probability of occurrence of instability mechanisms, among which plane failure, block toppling and wedge failure. The latter was found associated with the highest index measured (30%), followed by the flexural toppling mechanism (17%), providing a confirmation to the field survey and the results of geotechnical analyses. The integration with geologic and diagnostic investigations (e.g., boreholes, thin section observations) highlighted the intrinsic weaknesses of the rocks and stones to weathering, with a quite unexpected higher susceptibility to erosion and disaggregation characterizing the inner layers. Hence, the textural appearance of the erosion surfaces, the rock/stone structural properties and the TLS-based classification of the cliff sectors were mutually correlated, and the most unstable areas were mapped. As main implication for the conservation, on site monitoring system (i.e., biaxial inclinometers and crack gauges) was installed and targeted restorations have been properly designed.

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

2012-04-01

98

Enhanced chemical weathering of rocks during the last glacial maximum: a sink for atmospheric CO 2?  

Microsoft Academic Search

It has been proposed that increased rates of chemical weathering and the related drawdown of atmospheric CO2 on the continents may have at least partly contributed to the low CO2 concentrations during the last glacial maximum (LGM). Variations in continental erosion could thus be one of the driving forces for the glacial\\/interglacial climate cycles during Quaternary times. To test such

Wolfgang Ludwig; Philippe Amiotte-Suchet; Jean-Luc Probst

1999-01-01

99

Rocks  

NSDL National Science Digital Library

This interactive lesson about rocks that are found on Earth starts with a discussion of the lithosphere, granite rock and soil formation and then unifies this information with the rock cycle and the system of rock classification. Granite rock and some of its minerals, milky quartz, pink feldspar, hornblende, and biotite mica are then discussed. The site contains a review and a quiz and there are instructions for a hands on activity if the rocks and minerals are available.

100

The ubiquitous nature of accessory calcite in granitoid rocks: Implications for weathering, solute evolution, and petrogenesis  

USGS Publications Warehouse

Calcite is frequently cited as a source of excess Ca, Sr and alkalinity in solutes discharging from silicate terrains yet, no previous effort has been made to assess systematically the overall abundance, composition and petrogenesis of accessory calcite in granitoid rocks. This study addresses this issue by analyzing a worldwide distribution of more than 100 granitoid rocks. Calcite is found to be universally present in a concentration range between 0.028 to 18.8 g kg-1 (mean = 2.52 g kg-1). Calcite occurrences include small to large isolated anhedral grains, fracture and cavity infillings, and sericitized cores of plagioclase. No correlation exists between the amount of calcite present and major rock oxide compositions, including CaO. Ion microprobe analyses of in situ calcite grains indicate relatively low Sr (120 to 660 ppm), negligible Rb and 87Sr/86Sr ratios equal to or higher than those of coexisting plagioclase. Solutes, including Ca and alkalinity produced by batch leaching of the granitoid rocks (5% CO2 in DI water for 75 d at 25??C), are dominated by the dissolution of calcite relative to silicate minerals. The correlation of these parameters with higher calcite concentrations decreases as leachates approach thermodynamic saturation. In longer term column experiments (1.5 yr), reactive calcite becomes exhausted, solute Ca and Sr become controlled by feldspar dissolution and 87Sr/ 86Sr by biotite oxidation. Some accessory calcite in granitoid rocks is related to intrusion into carbonate wall rock or produced by later hydrothermal alteration. However, the ubiquitous occurrence of calcite also suggests formation during late stage (subsolidus) magmatic processes. This conclusion is supported by petrographic observations and 87Sr/86Sr analyses. A review of thermodynamic data indicates that at moderate pressures and reasonable CO2 fugacities, calcite is a stable phase at temperatures of 400 to 700??C. Copyright ?? 2005 Elsevier Ltd.

White, A. F.; Schulz, M. S.; Lowenstern, J. B.; Vivit, D. V.; Bullen, T. D.

2005-01-01

101

Lithium isotope ratios measured in scottish rivers and weathering of old silicate rocks.  

NASA Astrophysics Data System (ADS)

Silicate weathering is often considered as one of the most important sinks of atmospheric CO2 over geological timescales, but the palaeovariations of the silicate weathering rates are still debated and depend on the reliability of the chosen proxies. It has recently been suggested that Li isotopes significantly fractionate during continental erosion (Huh et al., 1999), and that 7Li measured in large rivers could mainly reflect the degree of silicate weathering at large scales. Two main reasons have been proposed, the high Li contents in silicate minerals relative to carbonates, and the preferential uptake of 6Li by secondary clay minerals. Nevertheless, very few measurements have been made either on source minerals or on weathering products. In principle, the study of small silicated catchments should allow us to better constrain the factors controlling the fractionation of Li isotopes. A previous study has shown that 7Li measured in Icelandic basaltic rivers displays a large range (from 10 to 25.3) which correlates well with estimated weathering rates (Gislason et al., 1996). Here we present results for about 15 rivers located in Northern Scotland, which show little evidence for anthropogenic contamination, and draining mainly old silicated terrains (>500Ma). These rivers have been sampled twice, in May and in October 2002, in order to constrain the seasonal variations of the Li signature. Major and trace elements have also been measured, as well as the dissolved organic carbon. All rivers have very low Ca/Na and Mg/Na ratios (average of 0.38 and 0.17 respectively), that corresponds to the end-member previously defined for silicate rivers (Gaillardet et al, 1999), suggesting negligible contribution from carbonate dissolution. Li contents range between 0.2 and 1.2 ppb and are significantly greater than in Iceland rivers (up to 0.09 ppb). First results for the May 2002 samples show a restricted range in 7Li (from 16 to 22) relative to basaltic rivers of Iceland, and this range compares well with shield rivers of the Orinoco and the Mississipi basins (13 - 22). 7Li display negative trends with Ca/Na and Mg/Na, unlikely to be explained by carbonate dissolution since rivers with high Ca/Na and Mg/Na have higher Si content and lower 7Li. These trends could rather be explained by a mixing between a seawater component, probably of atmospheric origin, and an intensive weathering of Ca-Mg silicate minerals present in soils.

Vigier, N.; Reynolds, B. C.; Burton, K. W.; Rogers, N. W.

2003-04-01

102

Comparison of rate of physical and chemical decomposition of rocks in weathering by wetting-drying and wetting-freezing-drying cycles  

NASA Astrophysics Data System (ADS)

The type and amount of weathering is determined by a complex combination of physico-chemical properties of the material and climatic conditions. Different materials respond differently in the same environments, but also the same materials can respond in different ways to the same processes in different environments. Weathering processes are often acting simultaneously at one site and it is sometimes hard to determine the exact weathering process that resulted in a certain weathering product. Rock characteristics, alternation of wetting and drying cycles and presence of joints and fissures are crucial for weathering processes. However, there is a big difference in the material response to precipitation depending on whether or not it is followed by freezing when more deterioration occurs. In order to study in detail the behaviour of different rocks under moisture and temperature regimes, weathering experiments with multiple cycles were carried out. The aim of these experiments was to obtain data about dynamics of decomposition of rocks under controlled laboratory conditions. Six rocks were selected for the weathering experiments due to their geological setting in mountain regions and their physico-chemical and mineralogical characteristics: red and grey sandstone (Germany), red sandstone (Serbia), tuffaceous rock (Island), gabbro (Serbia), and dunite (Germany). Samples of each of these rocks were examined in two separate experimental sets. First set consisted of 10 identical cycles that included 4 steps: raining, freezing, thawing and drying. After each step, sample mass was measured. Second set also had 10 cycles, but consisted of two steps: raining and drying. Leachate was collected after each cycle during both sets and volume, pH and conductivity was measured. Contents of Ca, K, Mg, Si, Al and Fe were determined in collected leachate after cycles 1, 5 and 10. Leachate characteristics were similar in both experimental sets. Volume, conductivity and pH of leachate were constant throughout all cycles. Furthermore, the concentrations of analyzed elements in the leachate were low throughout both sets of the experiment. As expected, freezing of samples did not show significant influence on concentration of tested elements in the leachate. However, the rate of mass loss differentiated samples from two experimental sets. Mass loss in samples submitted to freezing was constantly increasing with the number of cycles for all tested rocks. According to mass loss, dunite was most quickly deteriorating from all tested rocks during both experimental sets. Dunite lost about twice as much mass when frozen then when rained on. Both red sandstones behaved similarly to dunite. On the contrary, mass loss in grey sandstone, tuffaceous rock and gabbro during raining was <1%, but increased 4 times with freezing. Rock characteristics crucial for weathering are mineralogical composition and physico-mechanical characteristics. Obtained results indicate that the physical weathering processes are important in all tested rocks. Furthermore, they indicate that the rate of physical weathering during rainfall is not an indication of deterioration that will occur during freezing. Key words: weathering experiment, raining, freezing, rocks

Vezmar, T.; Kasanin-Grubin, M.; Kuhn, N. J.; Milovanovic, D.

2012-04-01

103

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

NASA Astrophysics Data System (ADS)

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.

Nozette, S.; Lewis, J. S.

1982-04-01

104

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

NASA Technical Reports Server (NTRS)

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.

Nozette, S.; Lewis, J. S.

1982-01-01

105

Chemical weathering of silicate rocks as a function of elevation in the southern Swiss Alps  

Microsoft Academic Search

Surface water and soil samples were collected from a series of small catchments on granitic gneiss in the Canton of Ticino in southern Switzerland. Elevations of the sampling points ranged from 220 to 2400 m; vegetation varied correspondingly from deciduous forest through coniferous forest to alpine pasture and essentially unvegetated rock and talus. Annual precipitation averaged 1.9 to 2.4 m.

James I. Drever; Jürg Zobrist

1992-01-01

106

The role of disseminated calcite in the chemical weathering of granitoid rocks  

Microsoft Academic Search

Accessory calcite, present at concentrations between 300 and 3000 mg kg?1, occurs in fresh granitoid rocks sampled from the Merced watershed in Yosemite National Park, CA, USA; Loch Vale in Rocky Mountain National Park CO USA; the Panola watershed, GA USA; and the Rio Icacos, Puerto Rico. Calcite occurs as fillings in microfractures, as disseminated grains within the silicate matrix,

Art F White; T HOMAS D. BULLEN; DAVISON V. VIVIT; MARJORIE S. SCHULZ; DAVID W. CLOW

1999-01-01

107

Modelling Compositional Change: The Example of Chemical Weathering of Granitoid Rocks  

Microsoft Academic Search

Perturbation on the simplex is an operation which can be used to numerically describe changes in the composition of, for example, soils, sediments, or rocks. The combination of perturbation and power transformation provides a strong tool for analyzing compositional linear processes in the simplex. When the process is constrained in the sense of a well-known starting (or final) composition, noncentred

Hilmar von Eynatten; Carles Barceló-Vidal; Vera Pawlowsky-Glahn

2003-01-01

108

Storage and release of fossil organic carbon related to weathering of sedimentary rocks  

Microsoft Academic Search

The biogeochemical carbon cycle, which plays an undeniable role in global climate change, is defined both by the size of carbon reservoirs (such as the atmosphere, biomass, soil and bedrock) and the exchange between them of various mineral and organic carbon forms. Among these carbon forms, fossil organic carbon (FOC) (i.e., the ancient organic matter stored in sedimentary rocks) is

Yoann Copard; Philippe Amiotte-Suchet; Christian di-Giovanni

2007-01-01

109

Weathering of Igneous, Metamorphic, and Sedimentary Rocks in a Semi-Arid Climate - An Engineering Application of Petrology  

NSDL National Science Digital Library

The identification of clay mineral assemblages in soils provides a unique opportunity to demonstrate how basic principles of petrology and geochemistry are applied to engineering design criteria in construction site preparation. Specifically, the problem investigates the conditions leading to the formation of smectite in soils and the resulting construction risk due to soil expansion. Students examine soils developed on igneous, metamorphic, and sedimentary rocks near Denver, Colorado. The field locations are areas of suburban growth and several have expansive soil problems. The 2-week exercise includes sample collection, description, and preparation, determining clay mineralogy by XRD, and measurement of Atterberg Plasticity Indices. This problem develops skills in X-ray diffraction analysis as applied to clay mineralogy, reinforces leacture material on the geochemistry of weathering, and demonstrates the role of petrologic characterization in site engineering.

Harrison, Wendy; Wendlandt, Ric

110

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)

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.

Strzelecki, Matt

2014-05-01

111

The Effects of Fire on Rock Art: Microscopic Evidence Reveals the Importance of Weathering Rinds  

Microsoft Academic Search

This paper presents results of the first study of pre-fire and post-fire samples collected from rock engravings and adjacent sandstone joint faces. A 2001 wildfire at Whoopup Canyon, Wyoming, stimulated a comparison of 1991 and 2003 samples. Opti- cal microscopy of ultra-thin sections, backscattered electron microscopy, x-ray (energy dispersive and wavelength dispersive) analysis of cross sections, and high-resolution trans- mission

Alice M. Tratebas; Niccole Villa Cerveny; Ronald I. Dorn

2004-01-01

112

Rock Solid  

NSDL National Science Digital Library

Rocks cover the earth's surface, including what is below or near human-made structures. With rocks everywhere, breaking rocks can be hazardous and potentially disastrous to people. Students are introduced to three types of material stress related to rocks: compressional, torsional and shear. They learn about rock types (sedimentary, igneous and metamorphic), and about the occurrence of stresses and weathering in nature, including physical, chemical and biological weathering.

Integrated Teaching And Learning Program

113

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)

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.

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

114

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)

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). However, these high concentration of potentially toxic elements can represent a serious hazard for the environmental quality of the Caledonian ecosystem which is a '' biodiversity hotspot' (Myers, 2000), which emphasize the strong need for characterizing the natural cycling of these elements upon weathering of ultramafic rocks. To reach this goal, we have studied the mineralogical distribution, crystal-chemistry and mass balance modelling of major (Si, Mg, Al, Fe, Mn) and trace elements (Ni, Cr and Co) in the freely-drained weathering profile developed in the serpentinized harzburgites of Mt Koniambo (West Coast of New Caledonia). Results show that both hydrothermal and meteoric processes contributed to the vertical differentiation of this freely drained weathering profiles in serpentinized ultramafic rocks. Finally, they also emphasize the importance of both redox reactions and interactions with Mn- and Fe-oxyhydroxydes (Fandeur et al., 2009a; 2009b) to explain the opposite behavior observed between very mobile Ni and almost immobile Cr (Fandeur et al., 2010). These results bring new insights on the geochemical behavior of trace elements upon weathering of ultramafic rocks under tropical conditions leading to the formation of supergene ore deposits. They also emphasize the interest of such a weathering site on ultramafic rocks under tropical climate to complemente the reference sites of the Critical Zone Exploration Network (CZEN). References Cluzel D., Aitchinson J.C. and Picard C. (2001) Tectonic accretion and underplating of mafic terranes in the Late Eocene intraoceanic fore-arc of New-Caledonia (Southwest Pacific): geodynamic implications. Tectonophysics, 340, 23-59. Coleman, R.G. (1977) Ophiolites: Ancient oceanic lithosphere?: Berlin, Germany, Springer-Verlag, 229p. Fandeur D., Juillot F., Morin G., Olivi L., Cognigni A., Fialin M., Coufignal F., Ambrosi J.P., Guyot F. and Fritsch E. (2009a). Synchrotron-based speciation of chromium in an Oxisol from New-Caledonia : Importance of secondary Fe-oxyhydroxydes. American Mineralogist, 94, 710-719. Fandeur

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

115

Rapid changes in the physical properties of rock and concrete during intertidal exposure; implications for weathering and engineering durability  

NASA Astrophysics Data System (ADS)

Water absorption is an important parameter affecting the susceptibility of rocky shore substrates and construction materials to wetting-drying, salt weathering and dissolution processes exposed in the intertidal zone. Strength is also an important determinant of durability and resistance to erosion processes such as abrasion. Here we examine changes in the water absorption properties and strength of representative materials used in the construction of coastal defences after 8 months exposure in the intertidal zone. Blocks of Portland limestone, Cornish granite and marine concrete were attached to shore platforms in Cornwall, UK, at Mean Tide Level. After 8 months exposure, Water Absorption Capacity (WAC) was determined (in both fresh water and synthetic seawater) for exposed and control samples, and strength was measured using Point Load and Equotip surface hardness tests. Differences between exposed and control samples were examined with ANOVA, using material type (3 levels; limestone, granite and concrete) and treatment (2 levels; control and field exposed) as fixed factors. There were significant differences in the WAC of field exposed materials compared to unexposed controls after 8 months (p = 0.02). Post-hoc Student Newman Kuels (SNK) tests also revealed significant material x treatment combinations in both fresh and synthetic seawater (p < 0.01). Field exposed concrete had lower water absorption compared to controls (p < 0.05), which was associated with the development of a surface bio-chemical crust (observed using SEM) and an increase in surface hardness (Equotip test, Student's t-test p = 0.05). In contrast, WAC of limestone in fresh and synthetic seawater was higher for exposed samples compared to controls, but was only significant in fresh water (p = 0.05). SEM examination suggests that extensive borehole erosion of exposed limestone probably explains these differences. Surface hardness of exposed limestone was lower than controls, which may also be associated with boring activity, but this was not statistically significant after 8 months. Water Absorption Capacity and surface hardness were no different between controls and field exposed granite samples. Point Load tests showed no detectable changes in bulk material strength of any material after 8 months exposure. Results are discussed with respect to early-stage physical changes of natural rock and artificial materials exposed in the intertidal zone during the construction of hard coastal defences. In particular, the role of material composition in determining responses to exposure, and temporal changes in the susceptibility of natural rock and concrete to different intertidal weathering and erosion processes, are discussed.

Coombes, Martin A.; Naylor, Larissa A.; Feal-Pérez, Alejandra

2010-05-01

116

Weathering of Igneous, Metamorphic, and Sedimentary Rocks in a Semi-arid Climate - An Engineering Application of Petrology  

NASA Astrophysics Data System (ADS)

Over the last 10 years, analytical methods have been introduced to students in CSM's undergraduate geological engineering program through a multi-year and multi-course approach. Beginning with principles and simple applications of XRD and SEM in sophomore Mineralogy and building on these skills in subsequent junior and senior year courses, geological engineers acquire proficiency in analytical methods. Essential workplace skills are thus acquired without adding an extra course in the undergraduate program. The following exercise is completed by juniors in an integrated Ig.-Met.-Sed. petrology course. The identification of clay mineral assemblages in soils provides a unique opportunity to demonstrate how basic principles of petrology and geochemistry are applied to engineering design criteria in construction site preparation. Specifically, the problem investigates the conditions leading to the formation of smectite in soils and the resulting construction risk due to soil expansion. Students examine soils developed on igneous, metamorphic, and sedimentary rocks near Denver, Colorado. The field locations are areas of suburban growth and several have expansive soil problems. The 2-week exercise includes sample collection, description, and preparation, determining clay mineralogy by XRD, and measurement of Atterberg Plasticity Indices. Teaching materials may be found at: http://serc.carleton.edu/NAGTWorkshops/petrology03/. This exercise accomplishes three objectives: First, skills in XRD analysis are developed by introducing students to concepts of particle size separation, particle orientation, and sequential analysis steps which are standard practices in clay characterization. Second, lecture material on the geochemistry of weathering of different rock types is reinforced. Students interpret the origin of clay mineral assemblages developed in soils derived from Precambrian gneisses, lower Paleozoic feldspathic sandstones, upper Paleozoic marine shales, and Tertiary basalts and volcaniclastics. Third, the role of petrologic characterization in site engineering is demonstrated. Students use Atterberg Limits measurements in conjunction with soil mineralogy to assess swelling potential and to design soil treatment needs for each building site.

Harrison, W. J.; Wendlandt, R. F.

2003-12-01

117

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)

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.

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

2014-08-01

118

Rocking Changes  

NSDL National Science Digital Library

In this earth science activity, learners conduct a series of short experiments to explore how rocks change. Learners will examine the components of the rock cycle as well as how rocks can change over time due to weathering, erosion, pressure and heat. In particular, learners will model igneous, sedimentary, and metamorphic rocks.

Workshop, Mission S.

2013-01-01

119

Rocks  

NSDL National Science Digital Library

In this activity students will use sample sets of igneous, metamorphic, and sedimentary rocks to learn how to identify the major rock types. They will write the key characteristics that would help them identify each of the rocks on the list. They will find and copy an image of each from the "Volcano World" slide show and answer the questions at the end of this activity. As a result of this lesson students will learn how to identify major rock types through their characteristic properties, especially through the Earth Science Reference Table identification charts, and understand how to find out what types of rocks can be found in a particular area using geologic maps, especially the one in the Earth Science Reference Table.

Lamont-Doherty Earth Observatory, The E.

120

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)

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 ?) took place at the expense of vermiculite, replacing the Mg interlayer cations (12.63 ?). Weathering took place mostly by low-pH solutions and in warm environment and the most extensive degree of weathering was at the HV4 site, in which the lode of vermiculite is the biggest. We propose that vermiculitization at Hafafit occurred due to a specific integration between the geologic setting (including rock type and tectonics) of the area and weathering processes producing the only vermiculite deposit in the ANS rocks of the ED of Egypt.

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

2010-09-01

121

Slope processes in weathered volcaniclastic rocks of the Camaldoli hill (Naples, Italy): Geomorphologic and Engineering-Geological aspects  

NASA Astrophysics Data System (ADS)

Following the geological study performed by Orsi et al. (this session), the main results of a geomorphologic and engineering-geological investigation of the stability conditions of the Camaldoli hill (urban area of Naples) are here presented. The Camaldoli hill, the highest peak of the Phlegraean Fields caldera (452 m asl), is characterized by relief energy of a few hundreds of meters, and by high slope gradients, which frequently reach the verticality. Low-order, structurally controlled channels drain the hillslopes; the development of stepped longitudinal profiles in the channels is related to the alternance of rocks and soils. The geological framework of the hill represent a further factor predisposing to mass movements and soil erosion. The Camaldoli hill is in fact characterized, as already highlighted by Orsi et al., by a basal sequence of jointed weak tuffs, overlain by some tens of metres of loose, unconsolidated pyroclastic terrains, ranging in age from about 12.000 and 4.000 yrs. BP. The latter deposits are generally weathered in their upper layers, as a consequence of interaction with decay agents and of past slope instabilities. Present-day morphodynamics of the hill is ruled by the occurrence of a variety of slope processes. Shallow landslides involve the weathered portion of the youngest pyroclastic products, showing features typical of slides or falls. Such events, which usually start in the upper reaches of the slope, may undergo different evolution, essentially controlled by the local slope morphology: (i) low-mobility soil slides-debris flows on open slopes; (ii) slides/falls evolving to hyperconcentrated flows along channels. The first processes have been seldom observed on open slopes, while the transition from slides/falls to hyperconcentrated flows along channels seems much more diffuse in the study area. The flows are generally fed, under intense to extreme rainfall events, by the re-mobilization of pre-existing landslide debris. The upper tuff formations (namely, the Neapolitan Yellow Tuff) are involved in falls and topple failures, which can detach volumes up to some tens of cubic metres, frequently reaching the lowest sectors of the slope, close to, if not within, the urbanized area. Eventually, accelerated soil erosion plays a major role in the open slopes, where evidences of sheet, rills and gullies have been surveyed. Joining the contribution of volcanologists and engineering-geologists, a tentative evaluation of the volumes susceptible to be mobilized by instability processes acting on the surficial, weathered cover of the loose pyroclastics was performed, adopting different methodologies. The so obtained results are compared and discussed in the paper: overall, they provide evidence of a widespread proneness to slope instability, which in turn may result into a serious threat to the diffuse settlements and infrastructures located at the Camaldoli’s foothill.

Calcaterra, D.; Coppin, D.; Palma, B.; Parise, M.; Orsi, G.; de Vita, S.; di Vito, M. A.

2003-04-01

122

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)

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.

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

2014-01-01

123

Complete Genome Sequence of Dyella jiangningensis Strain SBZ3-12, Isolated from the Surfaces of Weathered Rock.  

PubMed

Dyella jiangningensis strain SBZ3-12 can weather biotite and release Al and Fe from biotite under nutrient-poor conditions. Here, we report the first complete genome sequence of D. jiangningensis strain SBZ3-12, which may facilitate a better understanding of the molecular mechanism behind mineral weathering. PMID:24831147

Bao, Yuanyuan; Kwok, Amy Ho Yan; He, Linyan; Jiang, Jingwei; Huang, Zhi; Leung, Frederick Chi-Ching; Sheng, Xiafang

2014-01-01

124

Complete Genome Sequence of Dyella jiangningensis Strain SBZ3-12, Isolated from the Surfaces of Weathered Rock  

PubMed Central

Dyella jiangningensis strain SBZ3-12 can weather biotite and release Al and Fe from biotite under nutrient-poor conditions. Here, we report the first complete genome sequence of D. jiangningensis strain SBZ3-12, which may facilitate a better understanding of the molecular mechanism behind mineral weathering.

Bao, Yuanyuan; Kwok, Amy Ho Yan; Jiang, Jingwei; Huang, Zhi; Leung, Frederick Chi-ching; Sheng, Xiafang

2014-01-01

125

Structure and chemistry of bacterially populated acidic microenvironments found on naturally colonized and weathered circumneutral pH unsaturated waste rock from the Antamina Mine, Peru  

NASA Astrophysics Data System (ADS)

The microbial community present in geochemically well characterized field cells and experimental waste rock piles at the Antamina Mine, were examined using electron microscopy, culture dependent, and culture independent techniques. Relatively large populations of up to 10^8 bacteria per gram were found, despite the young age of the waste rock (1.5 years). Most samples were at alkaline pH and dominated by bacteria capable of neutral pH thiosulfate oxidation. One sample from a field cell producing drainage at a pH of 6.5 was dominated by acidophilic bacteria capable of Fe^2+ and S^0 oxidation. A weathered massive sulfide from this sample was thoroughly examined using a field emission gun scanning electron microscope equipped with a focused ion beam (FE-SEM-FIB). Bacteria were abundant as monolayer and agglomerate biofilms upon and within a porous schwertmannite precipitate, while no bacteria were found directly attached to clean sulfide surfaces. Pitting of pyrrhotite was observed beneath the microbially inhabited schwertmannite, while no pitting was observed in adjacent clean pyrrhotite surfaces indicating greater oxidation of the pyrrhotite surface beneath the schwertmannite. Some waste rock that has been exposed to natural surface weathering conditions for more than twice the amount of time, possessed larger total populations of bacteria, but did not support significant populations of acidophiles, suggesting a succession from neutrophiles to acidophiles takes place prior to the development of acid mine drainage. The development of the porous iron oxide film may be prerequisite for acidophilic bacteria to flourish, creating acidic microenvironments within a neutral bulk, ambient pH mine waste.

Dockrey, J. W.; Mayer, K. U.; Beckie, R. D.; Southam, G.

2009-12-01

126

Rapid changes in the physical properties of rock and concrete during intertidal exposure; implications for weathering and engineering durability  

Microsoft Academic Search

Water absorption is an important parameter affecting the susceptibility of rocky shore substrates and construction materials to wetting-drying, salt weathering and dissolution processes exposed in the intertidal zone. Strength is also an important determinant of durability and resistance to erosion processes such as abrasion. Here we examine changes in the water absorption properties and strength of representative materials used in

Martin A. Coombes; Larissa A. Naylor; Alejandra Feal-Pérez

2010-01-01

127

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

128

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

Microsoft Academic Search

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

P. A. Warke; B. J. Smith

1998-01-01

129

Geochemistry of lower Vindhyan clastic sedimentary rocks of Northwestern Indian shield: Implications for composition and weathering history of Proterozoic continental crust  

NASA Astrophysics Data System (ADS)

The western margin of the ˜1600 Ma Vindhyan basin of the Indian shield is marked by the presence of lower Vindhyan Group (LVG) comprising shales and sandstone with minor limestone, conglomerate and mafic volcanic flows at the base. Major and trace element compositions of sandstones and shales of the LVG have been investigated to infer the nature of provenance, weathering processes, and tectonic setting. Provenance analysis using trace elements and petrography suggests that the Archaean Banded Gneissic Complex (BGC) of Rajasthan is most likely the source of these clastic rocks. The shale and sandstone comprising lower part of LVG namely Khardeola Formation are distinctive in having high LILE such as Th, Rb, and K 2O, high ferromagnesian trace elements and also higher values of K 2O/Na 2O, Rb/Sr and (La/Yb) n ratios in comparison to succeeding sedimentary units comprising upper formations of the LVG. The significantly different geochemical characteristics of Khardeola Formation suggest change in provenance with sediments in the lower formation being derived from proximal source and those of upper formations from distal source. Based on REE patterns and Eu/Eu ? values, the clastic sediments of Khardeola formation can be modeled by a mixture of 60% Berarch Granite and 40% mafic volcanic rocks of Hindoli belt. On the other hand, the upper formations are best modeled with a mixture of 60% BGC granitic gneisses, 20% BGC mafic enclaves and 20% Berach Granite. CIA (chemical index of alteration) values and A-CN-K plot suggest that the source area experienced moderate to high degree of chemical weathering under warm and humid conditions. The shift of sediment source from local in the beginning to distal during later period suggests sedimentation in a tectonically active basin.

Raza, Mahshar; Dayal, A. M.; Khan, Abdullah; Bhardwaj, V. R.; Rais, Sarwar

2010-07-01

130

Weathering Experiment  

NSDL National Science Digital Library

After discussing weathering and erosion in class, students are asked to do a small amount of research on different types of chemical weathering, physical weathering, and erosion processes (mostly out of their textbook). Outside of class students then dirty at least four similar dishes with the same type, thickness and aerial extent of food, preferably baked on to ensure maximum stick. One dish is set aside as a control (no weathering or erosion will occur for that dish). For each of the remaining three dishes, students devise an experiment that mimics some sort of chemical weathering, physical weathering, or erosion process (freeze/thaw, sand abrasion, oxidation, etc.). Prior to the experiments, the thickness of food is measured. Experiments are timed, and at the end of the experiment each plate is turned over to determine how much which method removed the greatest aerial extent of food. Experimental results are compared to the control plate to determine the actual effectiveness. Erosion/weathering rates are determined by dividing the thickness of food removed by the experimental time. Students then calculate how long it would take to remove a pile of food the size of the Geology building (assume a 50 m radius sphere), and to remove an amount of food equivalent to the depth of the Grand Canyon. Students then compare these results to rock erosion and weathering rates, performing similar calculations using these "real" rates (see the full project description for details). Photos of each step and the scientists are encouraged in their 2-3 page writeup.

Stelling, Pete

131

Do Rocks Last Forever?  

NSDL National Science Digital Library

In this activity, students learn about chemical and mechanical weathering in rocks. From the background material, they will learn that the change that takes place in rocks is called weathering and that this term refers to the destructive processes that change the character of rock at or near the Earth's surface. Processes of mechanical weathering (or physical disintegration) break rock into smaller pieces but do not change its chemical composition; processes of chemical weathering (or rock decomposition) transform rocks and minerals exposed to water and atmospheric gases into new chemical compounds (different rocks and minerals), some of which can be dissolved away. Four experiments that illustrate the effects of mechanical and chemical weathering are provided.

132

Rocks, Rocks, Rocks  

NSDL National Science Digital Library

Students test rocks to identify their physical properties (such as luster, hardness, color, etc.) and classify them as igneous, metamorphic or sedimentary. They complete a worksheet table to record all of the rock properties, and then answer worksheet questions to deepen their understanding of rock properties and relate them to the cavern design problem.

Adventure Engineering

133

Rocks, Rocks, Rocks  

NSDL National Science Digital Library

Continuing the Asteroid Impact challenge, student teams test rocks to identify their physical properties (such as luster, hardness, color, etc.) and classify them as igneous, metamorphic or sedimentary. They complete a worksheet table to record all of the rock properties, and then answer worksheet questions to deepen their understanding of rock properties and relate them to the cavern design problem.

Adventure Engineering

134

Physical and chemical weathering  

NASA Astrophysics Data System (ADS)

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.

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

135

Weathering of Minerals  

NSDL National Science Digital Library

Students determine the % change in mass of mineral samples that have been placed in a rock tumbler. They graph the relationship between the hardness of the mineral and the % change in mass. They then consider why some of the mineral samples do not conform the the relationship they graphed. They investigate the physical properties of the outliers and consider how the physical properties contributed to the rate of weathering, and what kind of weathering occured in the rock tumbler.

Van Norden, Wendy

136

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)

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 ?29Si and ?30Si values (better than ± 0.23‰, 2SD) can be obtained if the area ablated is at least 50 × 50 ?m; or, alternatively, for the analysis of geometric features down to the width of the laser spot (about 20 ?m) 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 ?30Si to ca. ± 0.6‰, 2SD, for < 30 ?m 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 the micro-scale in a corestone sampled from a highly weathered roadcut profile in the tropical Highlands of Sri Lanka. The results show that secondary weathering products accumulated in cracks and grain boundaries are isotopically lighter than their unweathered plagioclase host, consistent with isotopically heavy dissolved Si found in rivers.

Schuessler, Jan A.; von Blanckenburg, Friedhelm

2014-08-01

137

The relative influence of lithology and weathering in shaping shore platforms along the coastline of the Gulf of La Spezia (NW Italy) as revealed by rock strength  

Microsoft Academic Search

Along the rock coasts of the Gulf of La Spezia, which are characterised by a Mediterranean microtidal environment, a limited number of small rock platforms are scattered, constrained in elevation within 5m above present-day sea level. This work deals with a number of these rock platforms, formed in different rock types (one in limestone and two in dolomite), that show

Alessandro Chelli; Marta Pappalardo; Isabel Arozarena Llopis; Paolo Roberto Federici

2010-01-01

138

Rock Cycle  

NSDL National Science Digital Library

Through five lessons, students are introduced to all facets of the rock cycle. Topics include rock and mineral types, material stresses and weathering, geologic time and fossil formation, the Earth's crust and tectonic plates, and soil formation and composition. Lessons are presented in the context of the related impact on humans in the form of roadway and tunnel design and construction, natural disasters, environmental site assessment for building structures, and measurement instrumentation and tools. Hands-on activities include experiencing tensional, compressional and shear material stress by using only hand force to break bars of soap; preparing Jeopardy-type trivia questions/answers for a class game that reinforces students' understanding of rocks and the rock cycle; creating "fossils" using melted chocolate; working within design constraints to design and build a model tunnel through a clay mountain; and soil sampling by creating tools, obtaining soil cores, documenting a soil profile log, and analyzing the findings to make engineering predictions.

Integrated Teaching And Learning Program

139

Weather Forecasting  

NSDL National Science Digital Library

This activity is designed to give students an understanding of how to forecast weather and how to use weather reports for their personal benefit. They will be able to tell what weather is, read weather instruments, understand basic cloud formations in relation to the weather, and make forecasts for two days in advance.

140

Honeycomb Weathering of Limestone Formations  

USGS Multimedia Gallery

Honeycomb weathering of sandstone located on the shores of Puget Sound occurs when expanding salt crystals break fragments of rock, creating a small hole that becomes larger as the process repeats itself over time....

2010-08-16

141

Weather Watch  

ERIC Educational Resources Information Center

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)

Bratt, Herschell Marvin

1973-01-01

142

Weather Basics  

NSDL National Science Digital Library

Students are introduced to the basics of the Earth's weather. Concepts include fundamental causes of common weather phenomena such as temperature changes, wind, clouds, rain and snow. The different factors that affect the weather and the instruments that measure weather data are also addressed.

Integrated Teaching And Learning Program

143

Weather Forecasting  

NSDL National Science Digital Library

Students consider how weather forecasting plays an important part in their daily lives. They learn about the history of weather forecasting â from old weather proverbs to modern forecasting equipment â and how improvements in weather technology have saved lives by providing advance warning of natural hazards.

Integrated Teaching And Learning Program

144

Severe Weather  

NSDL National Science Digital Library

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, flash floods, lightning, and tornadoes.

Forde, Evan B.

2004-04-01

145

Severe Weather  

ERIC Educational Resources Information Center

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…

Forde, Evan B.

2004-01-01

146

Severe Weather  

ERIC Educational Resources Information Center

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,…

Forde, Evan B.

2004-01-01

147

Severe Weather  

NSDL National Science Digital Library

Meteorologists disagree as to what constitutes severe weather. However, most concur that thunderstorms, tornadoes, and hurricanes, all considered to be "convective" weather, fit the definition of severe weather, which is a weather condition likely to cause hardship. This science guide will explore each of the three weather phenomena. By virtue of their locations, most students are familiar with at least one of the three severe weather events. Students who tour the web sites will have an opportunity to make connections between the familiar and the perhaps less understood weather events.

National Science Teachers Association (NSTA)

2005-04-01

148

Winter Weather  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...

Bellows, Mrs.

2009-09-28

149

Rivers, chemical weathering and Earth's climate  

Microsoft Academic Search

We detail the results of recent studies describing and quantifying the large-scale chemical weathering of the main types of continental silicate rocks: granites and basalts. These studies aim at establishing chemical weathering laws for these two lithologies, describing the dependence of chemical weathering on environmental parameters, such as climate and mechanical erosion. As shown within this contribution, such mathematical laws

Bernard Dupré; Céline Dessert; Priscia Oliva; Yves Goddéris; Jérôme Viers; Louis François; Romain Millot; Jérôme Gaillardet

2003-01-01

150

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

National Technical Information Service (NTIS)

Rocks on the ejecta blanket of Bonneville crater and along Spirits traverse over the Gusev plains towards the Columbia Hills are angular and strewn across the surface. They have a basaltic composition, and their Moessbauer spectra are dominated by an oliv...

C. Schroder G. Klingelhofer R. V. Morris D. S. Rodionov P. A. de Souza D. W. Ming A. S. Yen R. Gellert J. F. Bell

2005-01-01

151

Weather Forecasting  

NSDL National Science Digital Library

This website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather. Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Once you have a firm grasp on the science of weather forecasting, be sure to check out the other sections of this site, which include: "ice and snow," "our changing climate," "the water cycle," and "powerful storms."

2008-03-27

152

Weather Talk  

NSDL National Science Digital Library

Weather Talk is a primer on weather and naval meteorology. It provides a brief overview of major weather elements and is presented in a non-mathematical way, so that the reader will have a better understanding of the basic mechanisms of weather and use it to their advantage and safety in planning and carrying out their own activities. The site explains temperature, wind, pressure, atmospheric moisture, air masses and fronts, thunderstorms, tornadoes, hurricanes, and climatology.

153

Antarctic Weather  

NSDL National Science Digital Library

Visitors to this site can read a discussion about the weather in Anarctica, including why it is so cold, how weather observations are conducted there, and what role the continent plays in the global weather system. Links to related topics, a wind chill calculator, and a Fahrenheit-Celsius-Kelvin temperature converter are also provided.

154

Geochemical characteristics of Mesoproterozoic clastic sedimentary rocks from the Chakrata Formation, Lesser Himalaya: implications for crustal evolution and weathering history in the Himalaya  

Microsoft Academic Search

To evaluate the changes in the chemistry of upper continental crust during Precambrian time in the Himalaya, the oldest and best-preserved Mesoproterozoic clastic sedimentary rocks (pelites\\/shales and quartzites) from the Chakrata Formation, NW Lesser Himalaya, Uttar Pradesh have been analysed for major elements and a number of trace elements, including rare earth elements (REEs). When compared to post-Archean shales (for

S. A. Rashid

2002-01-01

155

World Weather  

NSDL National Science Digital Library

What's going on in the world of weather? Are there storms around Sri Lanka? What about the snows of Kilimanjaro? These can be pressing questions, indeed, and the World Weather app is a great way to stay in touch with weather patterns around the globe. Users will find that they can just type in a city name to see the current weather and also zoom around the globe as they see fit. It's a remarkable addition to the world of existing weather tracking apps and is compatible with all operating systems.

Elias, Jaume S.

2014-02-20

156

Weather Watcher  

NSDL National Science Digital Library

As spring progresses, weather conditions can continue to fluctuate dramatically, something that may foil vacation plans or other outings. Keeping that in mind, visitors may do well to download the Weather Watcher application created by Mike Singer. With this application, users may automatically retrieve the current weather conditions, look through hourly forecasts, keep abreast of severe weather alerts, and take a look at weather maps for almost any city world-wide. This application is compatible with all systems running Windows 98 and above.

Singer, Mike

157

The Influence Of Hydrothermal Alteration And Weathering On Rock Magnetic Properties Of Granites From The Eps-1 Drilling (soultz-sous-forÊts / France)  

NASA Astrophysics Data System (ADS)

The EPS-1 drilling in Soultz-sous-Forêts (Rhinegraben, France) recovered a core pro- file of Tertiary to Permo-Mesozoic sediments deposited on a Variscan granitic base- ment. Magnetic susceptibility (k) measurements on the core material revealed a con- tinous increase from the basement/cover boundary (kmean 0.4 x 10-3 SI) into the magnetite-bearing granite (kmean 13 x 10-3 SI) over a depth range of 1417 U 1555 m. Rock magnetic and mineralogic studies were performed for the fresh granite, the hydrothermally altered granite near a fault zone and the altered granite from the fossil land surface near the basement/cover boundary. The decrease in susceptibility can be correlated with a gradual decomposition of magnetite to hematite and an alteration of the matrix minerals feldspars, biotite and hornblende to clay minerals and carbon- ates. Along with this transition, characteristic rock magnetic signatures can be dis- criminated for different degrees of alteration. While temperature-dependent magnetic susceptibility k(T)-curves in fresh granites indicate a typical multidomain magnetite course with good reversibility, different types of irreversible courses are observed for the altered granite. However, hematite could not be identified in the k(T)-curves. Al- tered granite shows relatively weak magnetic behaviour in AF-demagnetisation exper- iments, untypical for hematite. The alteration of the fresh granite also causes a change in magnetic fabric parameter, especially of the anisotropy factor. The magnetic min- eralogy from the altered granite in respect to the changes in rock magnetic properties will be discussed.

Just, J.; Schleicher, A.; Kontny, A.; de Wall, H.

158

Weather Instruments  

NSDL National Science Digital Library

This Topic in Depth discusses the variety of instruments used to collect climate and weather data. The first two websites provide simple introductions to the many weather instruments. Bethune Academy's Weather Center (1) discusses the functions of psychrometers, anemometers, weather balloons, thermometers, and barometers. The Illinois State Water Survey (2) furnishes many images of various instruments that collect data daily for legal issues, farmers, educators, students, and researchers. The third website (3), created by the Center for Improving Engineering and Science Education (CIESE), provides a classroom activity to educate users on how to build and use weather instruments. By the end of the group project, students should know all about wind vanes, rain gauges, anemometers, and thermometers. Next, the Miami Museum of Science provides a variety of activities to help students learn about the many weather instruments including wind scales and wind chimes (4). Students can learn about the wind, air pressure, moisture, and temperature. At the fifth website, the Tyson Research Center at Washington University describes the devices it uses in its research (5). At the various links, users can find out the center's many projects that utilize meteorological data such as acid rain monitoring. The sixth website, a pdf document created by Dr. John Guyton at the Mississippi State University Extension Service, provides guidance to teachers about the education of weather patterns and instruments (6). Users can find helpful information on pressure systems, humidity, cloud patterns, and much more. Next, the University of Richmond discusses the tools meteorologists use to learn about the weather (7). While providing materials about the basic tools discussed in the other websites, this site also offers information about weather satellites, radar, and computer models. After discovering the many weather instruments, users can learn about weather data output and analysis at the Next Generation Weather Lab website (8). This expansive website provides an abundance of surface data and upper air data as well as satellite and radar images for the United States.

159

Predicting Weather  

NSDL National Science Digital Library

By performing the activities presented in this website, fourth grade students can learn about weather instruments and data collection. This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Each activity presented here includes both objectives and assessment techniques for the lesson. Sixteen different activity suggestions provide students and teachers with ample opportunities to explore weather in the classroom.

2008-03-28

160

Weather Experiments  

NSDL National Science Digital Library

Looking for fun ways to learn about weather? Weather Wiz Kids has 39 fun weather related experiments for you to try. These experiments can be done in the classroom with your friends or even at home! Some of the experiments on the site include: tornado in a bottle, make lightning, make it rain, cloud in a bottle, what's in the wind, the Doppler Effect, and baking soda volcano.

2010-01-01

161

Space weather  

NASA Astrophysics Data System (ADS)

Space weather is caused by conditions on the Sun and in the solar wind, the magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can affect human life or health. It affects man-made systems such as satellite electronics, terrestrial power grids and radio communications. This paper provides an overview of how space weather arises in the solar terrestrial system and how physical processes are able to cause space weather effects. We also discuss European perspectives and activities geared towards the possible initiation of a European Space Weather programme.

Glover, Alexi; Daly, Eamonn; Hilgers, Alain; Berghmans, David

2002-05-01

162

Science Sampler: Rocks in our pockets  

NSDL National Science Digital Library

Rocks contain so many stories within them that they're a natural for young scientists. To introduce students to rocks and their characteristics, begin your rocks unit with the following activities that develop their ability to make simple observations using their senses and conduct experiments to understand the effects of the weathering process and the rock cycle.

Plummer, Donna; Kuhlman, Wilma

2005-10-01

163

Carbon dioxide efficiency of terrestrial enhanced weathering.  

PubMed

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

Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

2014-05-01

164

Weather Forecasting  

NSDL National Science Digital Library

This activity (on page 2 of the PDF) is a full inquiry investigation into meteorology and forecasting. Learners will research weather folklore, specifically looking for old-fashioned ways of predicting the weather. Then, they'll record observations of these predictors along with readings from their own homemade barometer, graphing the correct predictions for analysis. Relates to linked video, DragonflyTV: Forecasting.

Twin Cities Public Television, Inc.

2005-01-01

165

Space Weather  

NASA Technical Reports Server (NTRS)

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.

Gallagher, Dennis L.

2010-01-01

166

Weather Instruments.  

ERIC Educational Resources Information Center

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…

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

167

On the persistence of 'weathering'  

NASA Astrophysics Data System (ADS)

The term 'weathering' has been in use for a very long time but it has come to mean different things to different people and hence, as scientific short-hand, it no longer functions. Here we question the tenets underpinning the most common usage of the term and note that the climate-process linkage implicit to the term is often missing and amounts to misdirection. Rather than climate as the primary driver behind specific weathering processes, it is argued that rock properties constitute the dominant control. Further, a case is made for reconsideration of our present bipartite (mechanical/chemical) division of weathering processes and of the weathering processes currently deemed to be 'those that occur'. As process studies become evermore reductionist in nature, so the functionality of the term comes more and more into question. The linkage between process and landform, the scaling-up attribute, is seen as a current weakness and one that will become more confusing as reductionist approaches continue. As a 'way forward' it is suggested that weathering, stripped of specific preconceived notions of specific processes, be envisaged as a function of energy transfer and be investigated in that light. Identification of new processes as well as restructuring of known processes, particularly when considering weathering on other planets, is a potential outcome of such an approach. With a process foundation rooted in energy transfer, 'rock decay' provides a better umbrella term and liberates researchers from the inescapable conceptual baggage implicit to the term 'weathering'.

Hall, Kevin; Thorn, Colin; Sumner, Paul

2012-05-01

168

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is a set of computer-based learning modules that teach students about meteorology from the point of view of learning how to forecast the weather. The modules were designed as the primary teaching resource for a seminar course on weather forecasting at the introductory college level (originally METR 151, later ATMO 151) and can also be used in the laboratory component of an introductory atmospheric science course. The modules assume no prior meteorological knowledge. In addition to text and graphics, the modules include interactive questions and answers designed to reinforce student learning. The module topics are: 1. How to Access Weather Data, 2. How to Read Hourly Weather Observations, 3. The National Collegiate Weather Forecasting Contest, 4. Radiation and the Diurnal Heating Cycle, 5. Factors Affecting Temperature: Clouds and Moisture, 6. Factors Affecting Temperature: Wind and Mixing, 7. Air Masses and Fronts, 8. Forces in the Atmosphere, 9. Air Pressure, Temperature, and Height, 10. Winds and Pressure, 11. The Forecasting Process, 12. Sounding Diagrams, 13. Upper Air Maps, 14. Satellite Imagery, 15. Radar Imagery, 16. Numerical Weather Prediction, 17. NWS Forecast Models, 18. Sources of Model Error, 19. Sea Breezes, Land Breezes, and Coastal Fronts, 20. Soundings, Clouds, and Convection, 21. Snow Forecasting.

Nielsen-Gammon, John

1996-09-01

169

Planetary Weather  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the weather conditions on other planets. After learning more about weather patterns, students research the weather on a given planet and create a visual display of the conditions there. It includes objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

170

Field characterisation of weathered Ankara andesites  

Microsoft Academic Search

This paper presents field and some index properties of weathered Ankara andesites, carried out over a period of 4 years. Ankara andesites are distributed widely around the city of Ankara, on which numerous important structures have been founded. Thus, the weathering characteristics of Ankara andesites, both from the engineering geological and the rock mechanics points of view are important. The

C. Karpuz

1997-01-01

171

Weatherizing America  

ScienceCinema

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.

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

2013-05-29

172

Weather One  

NSDL National Science Digital Library

This website contains summaries and lessons about various aspects of weather. This includes the seasons, types of clouds, air, winds, global warming, hurricanes, tornadoes and lightning. Worksheets are provided to accompany the lesson themes.

Friend, Duane

173

Weather Watchers  

NSDL National Science Digital Library

In this month-long interdisciplinary project students collect weather data, determine the best visual representation for displaying it, and discuss the patterns and implications of their findings. This resource includes extension and assessment suggestions and guiding questions.

2014-01-01

174

Weatherizing America  

ScienceCinema

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.

175

Space Weather  

NASA Astrophysics Data System (ADS)

Following James Van Allen's discovery of Earth's radiation belts (1958), it was immediately recognized that the space environment would be hostile to the communications satellites that had been envision by Arthur Clark (1945) and John Pierce (1955). Van Allen's discovery set off a burst of "space weather" research and engineering that continues to today, paralleling "space weather" research that had, prior to 1958, been directed toward understanding environment effects on cable and early wireless communications, electric power distribution, and pipelines. Van Allen's discovery also meant that the flight of humans above the sensible atmosphere would be fraught with more peril than mere weightlessness. This Van Allen lecture will discuss the space weather considerations that arose from Van Allen's discovery as well as space weather effects that occur from numerous other physical processes in the complex sun-heliosphere-magnetosphere environmental system.

Lanzerotti, L. J.

2005-05-01

176

Weatherizing America  

SciTech Connect

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.

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

2009-01-01

177

Weather Creator  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What can you do to make it rain or even snow? 4. Does it always snow when ...

Kshumway

2009-09-28

178

Weather Maps  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades K-5. It focuses on basic information about the weather and how different weather maps depict conditions. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

179

Role of Microorganisms in Wear Down of Rocks and Minerals  

Microsoft Academic Search

Rock weathering is an awkward term. Near and below the Earth’s surface, physical and chemical processes operate under direct or indirect control of living matter. Weathering, however, strongly relates to physical and chemical changes produced by the weather and its long-term average, the climate. Meteorological connotation of the term ignores the importance of biological interactions in the process of rock

Anna A. Gorbushina; W. E. Krumbein

180

Rock Cycle: Environments of Formation  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Rocks SciPack. It provides an in-depth exploration of the conditions and environment required during the formation of igneous, sedimentary, and metamorphic rocks. Igneous rock forms from the cooling and crystallization of magma. Sometimes the magma reaches Earth's surface and cools quickly; sometimes it does not reach the surface and thus cools slowly. Rocks at Earth's surface are subjected to processes of weathering and erosion, producing sediments as they are broken down. Sedimentary rock is formed when sediments are buried and solidified through various processes. Sedimentary rock buried deep enough may be transformed into metamorphic rock or melted down to magma. Rock formed deep within the crust (either igneous or metamorphic) may be forced up again to become land surface and even mountains by the forces that drive the motion of Earth's plates. Subsequently, this new rock too will erode. Learning Outcomes:� Realize that different rocks have specific origins, and that they are the product of any number of processes.� Identify the processes through which igneous, sedimentary, and metamorphic rock form.� Explain the role of intermediary materials such as sediment and magma in the formation of different kinds of rock.� Provide an overarching description of the steps in the rock cycle, the formation of sedimentary rock, the re-forming of rock by heat and pressure, and the process by which re-formed rock can return to the surface.

National Science Teachers Association (NSTA)

2006-11-01

181

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

SciTech Connect

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.

Bazilevskaya, Ekaterina [Pennsylvania State University, University Park, PA; Lebedeva, Marina [Pennsylvania State University, University Park, PA; Pavich, Milan [U.S. Geological Survey, Reston, VA; Rother, Gernot [ORNL; Parkinson, D. Y. [Advanced Light Source, LBNL; Cole, David [Ohio State University; Brantley, S. L. [Pennsylvania State University, University Park, PA

2012-01-01

182

Space Weather  

NASA Astrophysics Data System (ADS)

This volume provides a comprehensive overview of our current observational knowledge, theoretical understanding, and numerical capability with regard to the phenomena known as space weather. Space weather refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems, and can endanger human life or health. The rapid advance in these technologies has provided us with unprecedented capability and convenience, and we have come to rely on them more and more. Technology has reduced society's risk to many kinds of natural disasters, but through its own vulnerability, it has actually increased society's risk to space weather. Adverse conditions in the space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socioeconomic losses.

Song, Paul; Singer, Howard J.; Siscoe, George L.

183

Weathering and morphogenesis in a mediterranean climate, Calabria, Italy  

Microsoft Academic Search

Deeply weathered plutonic rocks occur widely in the Sila Massif, Calabria, southern Italy. Three representative weathering profiles developed on the hilltops indicate that sand represents more than 50% by weight throughout most of the weathering profile, and silt- and clay-size fractions are also well represented, filling the interstices among corestones. Both sand, and finer fractions of grus, and soil horizons,

Emilia Le Pera; Marino Sorriso-Valvo

2000-01-01

184

Enhanced Cenozoic chemical weathering and the subduction of pelagic carbonate  

Microsoft Academic Search

THE observed trend of increasing oceanic 87Sr\\/86Sr ratios during the late Cenozoic led Raymo et al.1 to propose that chemical weathering rates increased at this time as a result of enhanced weatherability of silicate rocks. They suggested that this was due in turn to continential uplift, primarily in the Himalayas and the Andes. Because weathering involves the reaction of silicates

Ken Caldeira

1992-01-01

185

Some topics on geochemistry of weathering: a review.  

PubMed

Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importance of complexes. Weathering is not only a destructive process. It can concentrate chemical species and form mineral deposits (kaolin, bauxite, Fe, Mn, P, Nb, Au). Weathering studies are important in pedology, engineering geology, hydrogeology, paleoclimatology and ecology. The use of stonemeal is based upon the study of rock weathering. PMID:17143414

Formoso, Milton L L

2006-12-01

186

Wild Weather  

NSDL National Science Digital Library

In this online, interactive module, students learn about severe weather (thunderstorms, hurricanes, tornadoes, and blizzards) and the key features for each type of "wild weather" using satellite images. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

187

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is one of several online guides produced by the Weather World 2010 project at the University of Illinois. These guides use multimedia technology and the dynamic capabilities of the web to incorporate text, colorful diagrams, animations, computer simulations, audio, and video to introduce topics and concepts in the atmospheric sciences. This module introduces forecast methods and the numerous factors one must consider when attempting to make an accurate forecast. Sections include forecasting methods for different scenarios, surface features affecting forecasting, forecasting temperatures for day and night, and factors for forecasting precipitation.

2010-01-01

188

Weather One  

NSDL National Science Digital Library

From the University of Illinois Extension comes the Weather One instructional Web site for kids. The lesson consists of six pages that cover various weather related topics including seasons, clouds, the atmosphere, wind, global warming, and storms. Each page describes the particular subject, provides related photographs, and contains several activities that reinforce the learning. For example, the clouds page shows how kids can make a cloud and create a collage out of simple material found around the house. The effective organization and clean look of the site will surely make it easy for students to follow and enjoy.

1969-12-31

189

Space Weather  

NSDL National Science Digital Library

With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on Space Weather and the terms scientists use to describe the everchanging conditions in space. Explosions on the Sun create storms of radiation, fluctuating magnetic fields, and swarms of energetic particles. These phenomena travel outward through the Solar System with the solar wind. Upon arrival at Earth, they interact in complex ways with Earth's magnetic field, creating Earth's radiation belts and the Aurora. Some space weather storms can damage satellites, disable electric power grids, and disrupt cell phone communications systems. This site provides images, activities, and interesting facts about all of these events.

2004-02-06

190

Weather Activity  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. Why does the wind blow? 2. When winds are blowing, how can you get them to stop? 3. What happens when the temperature is the same? 4. What happens when there is high relative humidity? 5. What ...

missy.jones@gmail.com

2009-09-28

191

Bacterial Colonization and Weathering of Terrestrial Obsidian in Iceland  

Microsoft Academic Search

Through weathering processes, volcanic rocks contribute both to nutrient flux into the biosphere and atmospheric CO2 drawdown. As rhyolitic rocks are of higher silica content and have lower concentrations of biologically-important elements than basalts they might be expected to be less easily weathered by a biota. Investigations on the microbial diversity and weathering of silica-rich rhyolitic glass (obsidian) from a

Aude Herrera; Charles S. Cockell; Stephen Self; Mark Blaxter; Joachim Reitner; Gernot Arp; Wolfgang Dröse; Thorsteinn Thorsteinsson; Andrew G. Tindle

2008-01-01

192

Putting Weather into Weather Derivatives  

NASA Astrophysics Data System (ADS)

Just as weather forecasting has a colorful and often farsighted history within geophysics, financial mathematics has a long and turbulent history within mathematics. Thus it is no surprise that the intersection of real physics and real financial mathematics provides a rich source of problems and insight in both fields. This presentation targets open questions in one such intersection: quantifying ``weather risk.'' There is no accepted (operational) method for including deterministic information from simulation models (numerical weather forecasts, either best guess or by ensemble forecasting methods), into the stochastic framework most common within financial mathematics. Nor is there a stochastic method for constructing weather surrogates which has been proven successful in application. Inasmuch as the duration of employable observations is short, methods of melding short term, medium-range and long term forecasts are needed. On these time scales, model error is a substantial problem, while many methods of traditional statistical practice are simply inappropriate given our physical understanding of the system. A number of specific open questions, along with a smaller number of potential solutions, will be presented. >http://www.maths.ox.ac.uk/~lenny/WeatherRisk

Smith, L. A.; Smith, L. A.

2001-12-01

193

Rad Rocks  

NSDL National Science Digital Library

Why do we have rocks? How are rocks formed? Why do we have rock cycles? There are all differnt kinds of rocks. What parts make up rocks? Can you sort rocks based on color, hardness, texture, layering, and particle size? How do the things rocks are made of determine how people use them? Organize rocks by color, weight, shape, and sizes. Click here to find out the basics about ...

2010-04-26

194

Weather Stations  

NSDL National Science Digital Library

This is a series of seven brief activities about Jupiter's atmosphere and weather. Learners will look at Jupiter's distinct banded appearance, violent storms, and clouds of many different colors. The activities are part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

195

Wonderful Weather  

NSDL National Science Digital Library

In this activity, learners conduct three experiments to examine temperature, the different stages of the water cycle, and how convection creates wind. These activities can be used individually or as a group for a lesson on weather. Note: boiling water is required for this activity; adult supervision required.

Workshop, Mission S.

2013-01-01

196

Today's Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and contains an online exploration of weather maps. Students use current maps to learn about and locate different features such as low-pressure areas and fronts. They then explore how these are related to severe storms.

197

Weather Wordsearch  

NSDL National Science Digital Library

Find the 12 weather related words in this word search brought to you by the Southeast Regional Climate Center (SERCC). When you finish finding all 12 words, hit the restart button to re-scramble the letters and start all over again!

2007-01-01

198

The Weather Doctor  

NSDL National Science Digital Library

Published by Spectrum Educational Enterprises, The Weather Doctor Web site is maintained by meteorologist Keith Heidorn. Visitors to the site will find everything from the joys of weather watching, to making rain, to weather history, to much more. Coming from someone who clearly enjoys what they do, this site explores unique aspects of weather including weather people, weather history, and weather and arts.

Heidorn, Keith.

2002-01-01

199

Heterogeneous distribution of nanophase aluminosilicate weathering products: Interpreting Martian weathering  

NASA Astrophysics Data System (ADS)

Nanocrystalline alteration products form in a range of soil and regolith weathering environments on Earth. In some weathering systems, poorly crystalline aluminosilicates such as allophane are distributed heterogeneously, as a function of depth in a vertical weathering profile or as a function of micro-environmental factors. Both of these factors can be important for understanding weathering processes on Earth and are particularly important to consider when interpreting allophane on Mars. Chemical and mineralogical measurements of Mars could be confounded by a vertical heterogeneity common to many weathering systems, because what is observed at the surface by spacecraft may not be representative of the complete weathering system. Appropriate caution should be taken to compare surface measurements of Mars to terrestrial weathering environments that examine soil columns. Also, nanocrystalline aluminosilicates are known to form coatings on regolith particles and rock fragments and can be compositionally distinct from weathering products formed in the greater regolith matrix. These types of coatings are particularly important to consider for interpreting remotely sensed spectral measurements because fragmented rocks, from sand to boulders, comprise much of the relatively dust-free surfaces of Mars. Due to their strong influence on spectral observations, coatings could be strongly detectable by thermal infrared spectroscopy relative to coexisting, weakly aggregated fine-grained weathering products, resulting in the oversampling of coatings. Consequently, detected nanocrystalline aluminosilicates phases may not represent the overall weathering system. As an example of these influences, we will consider the high-silica material(s) detected in Mars northern plains. Although there are several models for how this material formed, if it formed by in situ regolith weathering then the high-silica material was precipitated from dissolved regolith materials. Evidence for extensive cryoturbation in the northern plains indicates that subsurface materials have been brought to the surface, thus any vertical compositional heterogeneity resulting from weathering may have been subsequently homogenized. However, small-scale compositional heterogeneities could persist. Although high-silica material may coat particulates that comprise much of the surface, it may only represent only a micro-environment of the subsurface weathering. For example, although we suggest that the northern plains contain a silica-rich allophanic phase, weathering may also have produced more aluminous phases that are undetected in spectra because they do not form coatings. In addition, we will consider the possibility that Martian weathering produces poorly crystalline aluminosilicate phases that are structurally different from true allophane. We will report on the thermal infrared spectral difference between these phases. The details of Martian weathering processes that can be inferred from detection of allophane are limited by how well vertical and micro-environmental heterogeneities are understood and compensated for, for which input from the terrestrial weathering and soil science communities is essential.

Kraft, M. D.; Sharp, T. G.; Rampe, E. B.

2011-12-01

200

NOAA Weather Radio Hourly Weather Roundup Formatter.  

National Technical Information Service (NTIS)

The National Weather Service (NWS) is planning to replace the aging National Oceanic and Atmospheric Administration (NOAA) Weather Radio (NWR) as part of its modernization program. The Office of Meteorology (OM) selected the Hourly Weather Roundup (HWR) t...

G. F. Battel G. A. Kokolis J. E. Calkins

1994-01-01

201

Weather Watchers  

NSDL National Science Digital Library

Students are introduced to some essential meteorology concepts so they more fully understand the impact of meteorological activity on air pollution control and prevention. First, they develop an understanding of the magnitude and importance of air pressure. Next, they build a simple aneroid barometer to understand how air pressure information is related to weather prediction. Then, students explore the concept of relative humidity and its connection to weather prediction. Finally, students learn about air convection currents and temperature inversions. In an associated literacy activity, students learn how scientific terms are formed using Latin and Greek roots, prefixes and suffixes, and are introduced to the role played by metaphor in language development. Note: Some of these activities can be conducted simultaneously with the air quality activity (What Color Is Your Air Today?) of Air Pollution unit, Lesson 1.

Integrated Teaching And Learning Program

202

Weather Cycles  

NSDL National Science Digital Library

We are professionals in the teaching profession. We designed this project for children ranging from 4th grade to 6th grade. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. YOU WILL NEED: Paper with copied questions, Overhead projector and Students broken up into groups of 3. Form groups of three. Have each group explore the following simulation: Weather Maker Simulator Have students use the simulation to answer the following questions on paper. They should be discussing the questions in their groups. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...

Mitchell, Mrs.

2010-09-23

203

Weathering Corruption  

Microsoft Academic Search

Could bad weather be responsible for U.S. corruption? Natural disasters create resource windfalls in the states they strike by triggering federally provided natural-disaster relief. By increasing the benefit of fraudulent appropriation and creating new opportunities for such theft, disaster-relief windfalls may also increase corruption. We investigate this hypothesis by exploring the effect of disaster relief provided by the Federal Emergency

2008-01-01

204

Tithonium Chasma's Sedimentary Rocks  

NASA Technical Reports Server (NTRS)

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.

2003-01-01

205

Weather Science Hotlist  

NSDL National Science Digital Library

The Franklin Institute Online offers the metadata Web site Weather Science Hotlist. The page contains dozens of links organized into ten topics that include Online Exhibits, Weather Right Now, Background Information, Severe Weather, El Nino/ La Nina, Historical Weather, Career Connections, Activities, Atmosphere, and Weather Forecasting. A great source for anyone looking for online weather information.

2008-04-11

206

Weather Tamers  

NSDL National Science Digital Library

Problem-based learning experiences that extend at least two weeks provide an opportunity for students to investigate a real-world problem while learning science content and skills in an exciting way. Meteorology provides a wealth of problems students can investigate while learning specific science concepts and skills found frequently in middle level national and state curricula standards. The hands-on activity described in this article helps students learn about the science behind weather events by planning, constructing, and testing models of cities exposed to a series of simulated hurricanes and tornado conditions.

Sterling, Donna R.; Frazier, Wendy M.

2007-03-01

207

Mountain Weather  

NSDL National Science Digital Library

Mountains can be awe-inspiring both for the vistas they provide and for the weather events and long-term climate systems they support. This interactive feature illustrates how a moisture-laden air mass interacts with a mountain slope to produce characteristic patterns of precipitation over the mountain and surrounding areas. Viewers can see how clouds and precipitation form as the air mass ascends the windward side of the peak, and observe the rain shadow created on the leeward side by the descending, warmed, and moisture-depleted air. A background essay and list of discussion questions supplement the interactive feature.

208

Weather Photography  

NSDL National Science Digital Library

Ph.D. student Harald Edens describes himself as a "photographer of lightning, clouds, atmospheric optical phenomena and astronomy". His Web site entitled Weather Photography proves this by providing a stunning collection of photographs and movies of atmospheric optics, lightning, clouds, and astronomy. The author describes how the photographs were taken, what equipment was used, and even discusses many of the phenomenon being observed such as mirages and halos. An added bonus of this very interesting site is that the author generously allows free personal use of the photographs.

2000-01-01

209

Weather Activities  

NSDL National Science Digital Library

This entertaining, interactive website is the perfect tool to educate users about the basics of weather forecasting and reporting. The two educational modules, created by EdHeads, each contain three levels and are designed for grades four through nine. While discovering how to predict a three-day forecast, students learn about warm and cold fronts, wind direction and speed, high and low pressure systems, isobars, and humidity. Teachers can find a helpful guide discussing how best to use the site as well as providing an overview of science standards, lesson plans, and pre- and post-tests for students.

210

Destructive Weather  

NSDL National Science Digital Library

What are the effects of different types of destructive weather? Learn All About Hurricanes Record on your chart 3 things that you learned. Watch a Hurricane Video These are the devastating Effects of Hurricanes Learn All About Tornadoes Record on your chart 3 things that you learned. Watch a Tornado Video These are the devastating Effects of tornadoes Learn All About Thunderstorms Record on your chart 3 things that you learned. These are the devastating Effects of thunderstorms Follow these important tips To keep safe. ...

Alizabethirwin

2010-11-03

211

Rock Cycle  

NSDL National Science Digital Library

This interactive Flash animation about the rock cycle is suitable for a review or overview in an introductory level Physical Geology class. It includes animations, photos, and descriptions involving rock types and processes in the rock cycle.

Smoothstone; Company, Houghton M.

212

Observe the effects of mechanical weathering  

NSDL National Science Digital Library

In this interactive Earth science resource, students are first presented with six photographs, each featuring a different mechanical weathering event in which rock is broken down. Examples of the events include road damage due to ice heaving and the expansion of cracks in rocks due to tree growth. Students are instructed to click on each labeled image to see an enlarged version of it. In the enlarged view, brief text, often accompanied by visual cues such as arrows, explains the physical weathering process shown. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

213

The Weather Dude  

NSDL National Science Digital Library

The Weather Dude is a weather education Web site offered by meteorologist Nick Walker of The Weather Channel. For kids, the site offers a great online textbook entitled Weather Basics, which explains everything from precipitation to the seasons, using simple text and fun graphics. Other fun things for kids include weather songs, questions and quizzes, weather proverbs, and more. Teachers are also provided with helpful resources such as weather activity sheets and printable blank maps, as well as many other links to weather forecasts and information that will help make teaching about weather fun.

Walker, Nick.

2002-01-01

214

Rock fragmentation  

SciTech Connect

Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

1976-01-01

215

Rock engineering  

SciTech Connect

This book explores the fundamentals of applied geology and rock behavior. Topics range from geotechnical design techniques to the nature of rocks and rock masses. It also covers procedures such as rock blasting, drilling, cutting, and grouting. Includes references, case histories, and problems with solutions.

Franklin, J.A.; Dusseault, M.B.

1988-01-01

216

Igneous Rocks  

NSDL National Science Digital Library

This site explores igneous rocks in-depth through descriptions and pictures. The formation and distribution of this rock type are covered, as well as magma types associated with them (mafic to felsic). Classification of igneous rocks covers their texture and composition, including the difference between intrusive and extrusive. An alphabetical listing of rocks connects the user with a description, picture, tectonic association, and mineral composition of the rock. Bowens Reaction Series is covered as well, with associated rock types. A self-test allows the user to identify rocks by picture alone. Links are provided to sites with further information.

2007-12-12

217

rock properties  

NSDL National Science Digital Library

Rocks are the most common material on earth. We will learn about the parts that make up the rocks and sort rocks based upon color, hardness, texture, layering, and particle size. Lets review: What do you already know about rocks? Please write down your thoughts on a piece of paper. Now, click on the link below to find out what the definition of a rock is. *Intro to Rocks Please answer the questions below in complete sentences on your paper. 1. Rocks are made up of several particles. ...

Krystal

2009-12-14

218

Weathering of phosphorus in black shales  

NASA Astrophysics Data System (ADS)

Rock weathering is the ultimate source of phosphorus (P) to the oceans, where P can be a limiting nutrient for biological production. In this paper, P weathering is examined in soil chronosequences formed in weathering profiles on the organic-rich Woodford Shale, New Albany Shale and Green River Shale. At all sites, organic P and inorganic P concentrations reveal that P weathering is far from complete, prior to erosion. Carbon (C)/P ratios decrease significantly from unweathered shale to the weathered shale at all sites, which is driven by loss of total organic C with weathering. Here we characterize organic phosphorus across a weathering profile from the Woodford Shale using solid-state CPMAS 31P NMR spectroscopy techniques, revealing that P esters are the dominant forms of P during all stages of weathering. Certain P esters appear to be resistant to chemical weathering during the millions of years between deposition, uplift and erosion, possibly representing a significant long-term global sink for P.

Kolowith, Lauren Clark; Berner, Robert A.

2002-12-01

219

Investigaing Rocks  

NSDL National Science Digital Library

Your mission is to look at different types of rocks and be able to sort them based on color, feel, hardness, texture, layering they may have, and particle size they are made of. Identify how the properties of rocks determine how people use them. Click below to find out more about different kinds of rocks there are: Types of Rocks Now, Start Your Rock Collection! It's a race against time! Can you do it? Identify Rock Types How are rocks made? Check out: The Rock Cycle Now take the quiz: Diagram the rock cycle quiz Next, click the link to view the Virtual Quarry website. Here, you will be able to look at different rock ...

Lindsey, Tiffany A.

2010-06-21

220

Metamorphic Rocks  

NSDL National Science Digital Library

This interactive lesson on metamorphic rocks starts with a review of the rock cycle and goes on to describe the relationship between metamorphic rocks and their parent rock. The lesson then describes the agents of metamorphism (temperature, pressure, and chemical change) and moves into a discussion on contact, regional, and dynamic metamorphism. The remainder of the lesson consists of descriptions of foliated rocks such as slate, schist, and gneiss, and the non-foliates exemplified by quartzite and white marble.

221

Weathering of Yucatan Limestones: The Genesis of Terra Rosas.  

National Technical Information Service (NTIS)

The Yucatan Peninsula is the largest area of exposed carbonate rocks in the Caribbean region and provides an ideal site to study the weathering of limestones and dolomites under tropical conditions. Study of the residual Yucatan soils may provide informat...

W. C. Isphording

1974-01-01

222

Cockpit Weather Information Needs.  

National Technical Information Service (NTIS)

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 weat...

C. H. Scanlon

1992-01-01

223

Forecasting the Weather.  

ERIC Educational Resources Information Center

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)

Bollinger, Richard

1984-01-01

224

National Weather Service  

MedlinePLUS

HOME FORECAST Local Graphical Aviation Marine Rivers and Lakes Hurricanes Severe Weather Fire Weather Sun/Moon Long ... LOADING... Menu ? ACTIVE ALERTS ? FORECAST MAPS ? RADAR ? RIVERS, LAKES, RAINFALL ? AIR QUALITY ? SATELLITE ? PAST WEATHER ? Local forecast ...

225

Predicting Weather and Understanding Weather Systems  

NSDL National Science Digital Library

The assignment requires students to observe the weather map in the newspaper for four consecutive days. On the first day they are instructed to choose a location somewhere in the country. The will record the weather conditions there and observe any weather systems that exist elsewhere in the country. They then make predictions of how they expect weather in their location to change over the subsequent three days.

Grandy, Carla

226

Palmer Automatic Weather Station  

NSF Publications Database

Title : Palmer Automatic Weather Station Type : Antarctic EAM NSF Org: OD / OPP Date : December 06 ... Environmental Action Memorandum (Palmer Automatic Weather Station) To: Files (S.7 - Environment ...

227

Geotechnical description and JGS engineering classification system for rock mass  

Microsoft Academic Search

This paper presents the new classification system which identifies and designates rock masses based on their fundamental engineering characteristics. The system encompasses the stepwise procedural classification with three steps and a sub-step. The first-step is to classify rock mass into two types; (1) hard rock mass and\\/or its weathered or altered rock mass, and (2) soft rock mass that is

Masahiko OSADA; Akio FUNATO; Ryunoshin YOSHINAKA; Hiroshi ITO; Takashi KITAGAWA; Katsuji SASAKI; Kenji AOKI; Omer AYDAN; Shinji AKUTAGAWA; Hideo KIYA; Keizo KUWAHARA; Masahiro SETO; Soichi TANAKA; Kazuo TANI; Toshiaki MIMURO; Takayuki MORI

2005-01-01

228

This Rock is Your Rock, This Rock is My Rock  

NSDL National Science Digital Library

In this activity students discover that the types and relative proportion of minerals that occur together in a rock tell scientists the story of how that rock was formed. They also learn that rocks are named based on how they formed and by the types, amounts, and sizes of minerals in the rocks. Students will realize that one of the most important skills a geologist needs when studying a rock is the ability to observe and describe what he or she sees. As a result of this activity students will improve their observational skills and learn that rocks are made up of one or more minerals.

229

Effects of climate on chemical_ weathering in watersheds  

Microsoft Academic Search

Climatic effects on chemical weathering are evaluated by correlating variations On 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 inappropriate surrogate for chemical weathering. Chemical fluxes are

Art F. White; Alex E. Blum

1995-01-01

230

Release of biodegradable dissolved organic matter from ancient sedimentary rocks  

Microsoft Academic Search

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

Sarah Schillawski; Steven Petsch

2008-01-01

231

Sedimentary Rocks  

NSDL National Science Digital Library

This interactive Flash animation provides an overview of sedimentary rocks for introductory level high school or undergraduate Earth science or physical geology courses. It includes pictures and supplementary information about sedimentary rock formation and erosion.

Smoothstone; Company, Houghton M.

232

Weathering of granodioritic crust, long-term storage of elements in weathering profiles, and petrogenesis of siliciclastic sediments  

Microsoft Academic Search

The bulk composition and mineralogy of the Toorongo Granodiorite, Australia, are similar to average upper continental crust (AUCC). Weathering characteristics of the Toorongo profile consequently provide insight into large-scale chemical weathering of the upper crust. In situ weathered materials of the profile do not reflect parent granodiorite composition in quartz-plagioclase-K-feldspar (Q-P-K) or in quartz-feldspar-rock fragment (Q-F-L) compositional space. Intensive in

H. Wayne Nesbitt; G. Markovics

1997-01-01

233

Neutralization of atmospheric acidity by chemical weathering in an alpine drainage basin in the North Cascade Mountains  

Microsoft Academic Search

The most important weathering reaction that neutralizes incoming atmospheric acidity in the South Cascade Lake basin is weathering of calcite, which occurs in trace amounts in veins, on joint surfaces, and as a subglacial surficial deposit. Although the basin is underlain by igneous and high-grade metamorphic rocks, weathering of plagioclase is quantitatively negligible; the principal silicate weathering reaction is alteration

James I. Drever; Douglas R. Hurcomb

1986-01-01

234

Rock Identification  

NSDL National Science Digital Library

This hands-on activity covers the basics of rock identification. After a brief discussion of the terms 'rock' and 'mineral', students will study the characteristics and classifications of the three major rock groups (igneous, metamorphic, and sedimentary). Using an online tutorial to test their knowledge and to learn more about rocks, they will identify 10 different specimens, record their observations, and provide a name for each.

Pratte, John

235

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)

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.

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

2005-01-01

236

Evolution of Oxidative Continental Weathering  

NASA Astrophysics Data System (ADS)

The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen levels increased above 10-5 times the present atmospheric level. This value is based on the loss of sulphur isotope mass independent fractionation (S-MIF) from the rock record, beginning at 2.45 Ga and disappearing by 2.32 Ga. However, a number of recent papers have pushed back the timing for oxidative continental weathering, and by extension, the onset of atmospheric oxygenation several hundreds of million years earlier despite the presence of S-MIF (e.g., Crowe et al., 2013). This apparent discrepancy can, in part, be resolved by the suggestion that recycling of older sedimentary sulphur bearing S-MIF might have led to this signal's persistence in the rock record for some time after atmospheric oxygenation (Reinhard et al., 2013). Here we suggest another possibility, that the earliest oxidative weathering reactions occurred in environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts, riverbed and estuarine sediments, and lacustrine microbial mats. We calculate that the rate of O2 production via oxygenic photosynthesis in these terrestrial microbial ecosystems provides largely sufficient oxidizing potential to mobilise sulphate and a number of redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. These findings reconcile geochemical signatures in the rock record for the earliest oxidative continental weathering with the history of atmospheric sulphur chemistry, and demonstrate the plausible antiquity of a terrestrial biosphere populated by cyanobacteria. Crowe, S.A., Dossing, L.N., Beukes, N.J., Bau, M., Kruger, S.J., Frei, R. & Canfield, D.E. Atmospheric oxygenation three billion years ago. Nature 501, 535-539 (2013). Reinhard, C.T., Planavsky, N.J. & Lyons, T.W. Long-term sedimentary recycling of rare sulphur isotope anomalies. Nature 497, 100-104 (2013).

Konhauser, Kurt; Lalonde, Stefan

2014-05-01

237

Rock Jeopardy!  

NSDL National Science Digital Library

Students reinforce their understanding of rocks, the rock cycle, and geotechnical engineering by playing a trivia game. They work in groups to prepare Jeopardy-type trivia questions (answers) and compete against each other to demonstrate their knowledge of rocks and engineering.

Integrated Teaching And Learning Program

238

Sedimentary Rocks  

NSDL National Science Digital Library

Create a poster about sedimentary rocks! Directions: Make a poster about sedimentary rocks. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about sedimentary rocks. (5 points each) (15 points) Write at least a three sentence summary of your poster ...

Walls, Mrs.

2011-01-30

239

Rock Finding  

ERIC Educational Resources Information Center

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…

Rommel-Esham, Katie; Constable, Susan D.

2006-01-01

240

Rock Art  

ERIC Educational Resources Information Center

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…

Henn, Cynthia A.

2004-01-01

241

Rock Games.  

ERIC Educational Resources Information Center

Elementary school children are given cards containing specific criteria for doing one or two tasks: sorting or arranging rocks. Sorting tasks involve children in picking out rocks with particular characteristics, such as color or shape. In the arranging tasks children are asked to arrange rocks according to size or value. (RM)

Topal, Cathy Weisman

1985-01-01

242

WeatherNet  

NSDL National Science Digital Library

WeatherNet, brought to us by The Weather Underground at University of Michigan, aims to be the premier site of weather links on the Internet. Besides the topical tropical storm page, you can view Accu-Weathers graphics including Nexrad imagery, satellite photos, surface maps, and forecast maps.

1998-01-01

243

Teaching Weather Concepts.  

ERIC Educational Resources Information Center

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…

Sebastian, Glenn R.

244

Backyard Weather Station  

NSDL National Science Digital Library

Students use their senses to describe what the weather is doing and predict what it might do next. After gaining a basic understanding of weather patterns, students act as state park engineers and design/build "backyard weather stations" to gather data to make actual weather forecasts.

Integrated Teaching And Learning Program

245

Future Weather Station  

NSDL National Science Digital Library

In this activity students build dioramas of futuristic weather stations to demonstrate their knowledge of weather forecasting. They will work in groups to research modern forecasting equipment and techniques, and then build a weather station that will do something we cannot do at present (such as stopping tornadoes). They will present their dioramas and then discuss the pros and cons of controlling the weather.

246

Weather in Your Life.  

ERIC Educational Resources Information Center

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…

Kannegieter, Sandy; Wirkler, Linda

247

The role of basalt weathering on climate: the Siberian traps  

NASA Astrophysics Data System (ADS)

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.

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

2003-04-01

248

High Resolution Magnetostratigraphy Susceptibility (MS) and Gamma Radiation (GR) Measurements from Three Coeval Upper Cretaceous Stratigraphic Sequences in Colorado: Testing MS and GR Variations Arising from Detrital Components in Variably Weathered Marine Sedimentary Rocks (Invited)  

NASA Astrophysics Data System (ADS)

We have measured the magnetic susceptibility(MS) and gamma radiation (GR) for three Upper Cretaceous marine sedimentary sequences that span the Cenomanian-Turonian (C-T) boundary exposed as part of the Western Interior Seaway in Central Colorado. The purpose of this study was three fold: (1) to evaluate the combined potential of MS and GR as a correlation tool using well-studied sequences that have been previously correlated based on high-resolution lithostratigraphy, (2) to evaluate the effect of differential weathering on MS and GR values, and (3) to evaluate how their relationship with each other changes. This work includes sampling of the moderately weathered Global Boundary Stratotype Section and Point (GSSP) for the C-T boundary that is exposed in a railroad cut near Pueblo, CO. A nearby (~1 km) coeval section in an old road cut, where weathering is pronounced, was also sampled, as was fresh material through the C-T boundary interval from a core drilled ~40 km to the west of Pueblo (the USGS#1 Portland Core). MS was measured in the laboratory at LSU on samples collected at ~5 cm intervals from each of these sequences. GR was measured in the field at ~5 cm intervals on the two outcrop sequences, using a portable GR spectrometer. In addition, the GR also was measured on samples collected for MS measurement, using a laboratory-based Germanium detector. It is argued that both MS and GR data sets are controlled by detrital fluxes into the marine environment, although the effect of weathering, if any, on these parameters when exposed in outcrop, is not well documented. In addition, these parameters are controlled by different detrital components that may be derived from different sources, or be differentially concentrated within the marine system. Here we report the results of a number of experiments designed to evaluate how the MS and GR data sets co-vary, and to test their usefulness as correlation tools in stratigraphically. We have also examined the effects of varying magnitudes of weathering on these stratigraphic relationships. Of great interest to us has been to evaluate if, and how well these data sets record climate cycles, and how the MS and GR data are affected by weathering, if at all. The results of this work will be discussed in our presentation.

Ellwood, B. B.; Tomkin, J. H.; Wang, W.

2010-12-01

249

Australian Severe Weather  

NSDL National Science Digital Library

The Australian Severe Weather Web site is maintained by self proclaimed severe weather enthusiasts Michael Bath and Jimmy Deguara. Other weatherphobes will fully appreciate what the authors have assembled. Everything from weather images, storm news, tropical cyclone data, bush fire and wild fire information, weather observation techniques, and even video clips and Web cam links. Although these other items make the site well rounded, the extensive amount of categorized weather pictures (which are quite extraordinary) are reason enough to visit.

250

What's the Weather?  

NSDL National Science Digital Library

In this lesson, students use daily observations, videos, and activities to learn about meteorology and the changing nature of weather. They will also identify weather events that are commonly reported in the news and discuss how weather affects lives. They should understand that weather can change daily and weather patterns change over the seasons, and that it has characteristics that can be measured and predicted. Suggestions for an optional field trip are also provided.

2005-01-01

251

Quantifying weathering advance rates in basaltic andesite rinds with uranium-series isotopes: a case study from Guadeloupe  

Microsoft Academic Search

Weathering of basaltic rocks plays an important role in many Earth surface processes. It is thus of great interest to quantify their weathering rates. Because of their well-documented behaviors during water-rock interaction, U-series isotopes have been shown to have utility as a potential chronometer to constrain the formation rates of weathering rinds developed on fresh basaltic rocks. In this study,

L. Ma; F. J. Chabaux; E. Pelt; M. Granet; P. B. Sak; J. Gaillardet; S. L. Brantley

2010-01-01

252

Rock and the Rock Cycle  

NSDL National Science Digital Library

This interactive rock cycle shows students how all rock types are recycled into other types, and how the cycle progresses. Materials include the definitions of each rock type (igneous, sedimentary, metamorphic), how they change over time, and how tectonic movements help to drive the process.

253

Global chemical weathering and associated P-release  

NASA Astrophysics Data System (ADS)

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)

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

2014-05-01

254

'Escher' Rock  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks

[figure removed for brevity, see original site] Figure 1

This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may 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. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters.

The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water.

Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend.

These data were taken by the rover's alpha particle X-ray spectrometer.

2004-01-01

255

Interactive Weather Information Network  

NSDL National Science Digital Library

Offered by the National Oceanic and Atmospheric Administration (NOAA), the Interactive Weather Information Network (IWIN) is a collection of interactive weather maps and satellite images that is updated every five seconds. Visitors can see cloud cover animation loops, NEXRAD Radar images of precipitation, a map of all current weather fronts, and an interactive national map to see information about any particular state. Other information on the site includes a listing of any active weather warnings, a link for world weather data, and more, making this a must-see site for all those users interested in the most current weather happenings anywhere.

2002-01-01

256

Edheads: Weather Activities  

NSDL National Science Digital Library

This great interactive resource allows you multiple opportunities to explore weather related concepts. After clicking start, you will learn how to report and predict the weather at the underground W.H.E.D weather caves! Each activity has three different levels, and each level is harder than the one before it. This resource also includes a teacher's guide (with pre- and post- tests) and links to additional weather related resources. These include a weather glossary, a Fahrenheit to Celsius & Celsius to Fahrenheit converter, and a link that provides information about interesting people in the weather field.

2010-01-01

257

Pilot weather advisor  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

258

Weather and Precipitation  

NSDL National Science Digital Library

How are different types of weather common in our everyday life? How can we use what we know about weather to go about everyday activities? First, use the Weather Chart to write down what you learn from each website. Then, go to Weather Information Website #1 and click on "What's the Weather?" to dress the bear for the day. Make sure you write it down on your graphic organizer. Next, go to Weather Information Website #3 and explore at least 5(clouds, thunderstorms, winter storms, etc.) of ...

Jones, Ms.

2012-04-12

259

The Weather Man  

NSDL National Science Digital Library

This project is designed to let you be "The Weather Man" and control the weather through simulation, and hands on experience, followed by guided questioning and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. How does humility play a role in weather? How does more or less change weather? 2. What is water vapor? Where does it come from? 3. What happens when the weather drops below zero degrees? ...

Grasser, Mrs. E.

2012-09-27

260

'Earhart' Rock  

NASA Technical Reports Server (NTRS)

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.

2004-01-01

261

Science Rocks!  

ERIC Educational Resources Information Center

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…

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

2010-01-01

262

Reaping Rocks  

NSDL National Science Digital Library

This is an activity about collecting, describing and classifying terrestrial and lunar rocks. Learners will collect and describe rocks of varying texture, color and shapes. Descriptors will include color, presence or absence of grains and grain size, textures, banding and other patterns. From the descriptions, learners will classify their collected rocks and extend their knowledge to classify lunar rocks. This activity is in Unit 1 of the Exploring the Moon teacher's guide and is designed for use especially, but not exclusively, with the Lunar Sample Disk program.

263

Rock flows  

NASA Technical Reports Server (NTRS)

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.

Matveyev, S. N.

1986-01-01

264

Sedimentary Rocks  

NSDL National Science Digital Library

This in-depth description of sedimentary rocks covers their classification as clastic, carbonate, or chemical/biochemical as well as their depositional environments, known as long and short clastic systems and carbonate depositional environments. It also presents a discussion of sedimentary rock evolution with an evolutionary diagram and a section on tectonics and sedimentary rocks. An alphabetical list of rocks with photograph, quartz-feldspar-lithic (QFL) composition, description, tectonic association, and formation and environments is given. Identification keys, both basic and QFL are also provided.

Fichter, Lynn

265

Specular Scattering from Rock Surfaces at the Viking Lander Sites  

NASA Astrophysics Data System (ADS)

Over the next decade one focus of Mars exploration will be a series of landers and rovers, starting with Mars Pathfinder. An important component of the landed exploration of Mars will be to determine the chemistry and mineralogy of rocks. Important objectives for future measurements of rocks on Mars will be determination of coating thickness and properties and whether sensors will measure rock coatings or the underlying rock. In addition, the coatings themselves are of interest as to their origin and the relation of coatings to rock weathering on Mars. Coated rock surfaces are present at the Viking Lander sites and are found to have a very high reflectance in the forward scattering direction (i.e., specular reflection), similar to varnished rock surfaces found in arid terrestrial settings. The presence of these coatings may indicate that rock breakdown is largely by macroscopic spalling, providing surfaces that are relatively long-lived and capable of developing coatings through on-going weathering processes.

Guinness, E. A.; Arvidson, R. E.; Shepard, M. K.

1996-03-01

266

Dynamic tensile strength of lunar rock types  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

267

Dynamic tensile strength of lunar rock types  

NASA Astrophysics Data System (ADS)

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.

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

1981-03-01

268

On Observing the Weather  

NSDL National Science Digital Library

In this article, Mount Washington Observatory meteorologist Tim Markle shares the ins and outs of his daily weather-observing routine and offers insights on making weather observations at home or at school.

Crane, Peter

2004-05-01

269

Weather and Stroke Risk  

MedlinePLUS Videos and Cool Tools

... the lower right-hand corner of the player. Weather and Stroke Risk HealthDay February 13, 2014 Related MedlinePlus Page Stroke Transcript Weather changes may significantly affect stroke risk, a new ...

270

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. ...

271

In Depth Winter Weather  

NSDL National Science Digital Library

Winter Weather is an In-Depth Special Report form the National Center for Atmospheric Research. It contains articles, images, activities, video clips, and interactive graphs to inform learners about meteorology and weather in the colder seasons.

2012-01-01

272

Multipurpose Weather Roundup Program.  

National Technical Information Service (NTIS)

Program RWR9 reads Surface Airways Observations (SAO's) from the local AFOS database and reformats them into plain language collectives for Hourly, State, and Regional Weather Roundups. Output is suitable for direct transmission on the state weather wire....

W. E. Sunkel

1983-01-01

273

Favorite Demonstration: Differential Weathering  

NSDL National Science Digital Library

In this inquiry-based demonstration, the consumption of a Baby Ruth candy bar is used to nurture students' interest in chemical and physical weathering. In addition, two other concepts can be illustrated: the difference between weathering and erosion and

Francek, Mark

2002-10-01

274

Weather in Antarctica  

NSDL National Science Digital Library

This homepage includes information about the weather in Antarctica and links to pages on the climate, wind chill, clouds, snow and ice, and pressure and storms of Antarctica. The current weather conditions updated automatically at various stations are also provided.

Hutchings, Thomas

1998-01-01

275

Stormfax Weather Services  

NSDL National Science Digital Library

This site offers links to a variety of weather information, including national, international and local weather maps and forecasts, satellite and radar imagery, and severe weather warnings. There are also links to diverse resources such as fire maps, glacier inventories, snow depths, storm surges and tropical storms. There are reports and advisories about El Nino and La Nina. The site also has a glossary of weather terms and conversion charts for temperature, wind speed and atmospheric pressure.

2002-06-10

276

Carbonatisation of Weathered Peridotites in Laboratory Experiments  

NASA Astrophysics Data System (ADS)

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 former mesh texture. Meshes that were initially filled with weathered olivine, were preferred sites of reaction relative to fresh olivine and serpentine. Dissolution of the mesh fillings and subsequent replacement by calcite resulted in Mg- and Si-enrichment in the fluid. The results confirm that hydrothermal alteration of ultramafic rocks may lead to Mg-depletion and ophicalcite formation and, in particular, highlight the role of weathering in enhancing the carbonatisation of peridotites. Our study has potential implications for industrial mineral sequestration of CO2 since weathering is commonly extensive in peridotites. The removal of Mg from the site of carbonatisation would be an undesired effect during CO2 injection into ultramafic rocks, but with a Ca-source available carbonatisation may still be effective. References: Beinlich, A., Austrheim, H., Glody, J., Erambert, M. and Andersen, T.B. (2010), Geochim. Cosmochim. Acta, in press. Folk, R.L. and McBride, E.F. (1976), Geology, 4(6): 327-332. Kelemen, P.B. and Matter, J. (2008), PNAS, 105(45): 17295-17300.

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

2010-12-01

277

Weather Maps in Motion  

NSDL National Science Digital Library

In this activity, students learn to interpret current weather maps. They will observe weather map loop animations on the internet, learn the concept of Zulu time (Universal Time Coordinated, UTC) and visualize the movement of fronts and air masses. They will then analyze a specific weather station model, generate a meteogram from their observations, and answer a set of questions about their observations.

Burrows, Charles

278

Aviation weather services  

NASA Technical Reports Server (NTRS)

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.

Sprinkle, C. H.

1983-01-01

279

Pinpointing the weather  

Microsoft Academic Search

Accurately predicting weather in regions like the west, which have a variety of climates in high mountain, coastal, and desert sites, can be tricky. Now the National Weather Service (NWS) is testing an experimental computer model that will help forecasters predict weather conditions with greater detail. The Eta-10 model allows forecasters in 24 western NWS offices to monitor the development

Elaine Friebele

1997-01-01

280

Hot Weather Tips  

MedlinePLUS

... A A + A You are here Home HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and those ... conditions such as vascular disease or diabetes, the weather does not have to hit 100 degrees to ...

281

Predicting Seasonal Weather  

NSDL National Science Digital Library

This module is about a new method of predicting seasonal weather. The site describes the effects of El Nino on global weather and the accuracy of the new model. It includes links to classroom resources for a variety of weather-based units.

Dybas, Cheryl

2008-12-07

282

Rockin' Rocks  

NSDL National Science Digital Library

Let's use the Big6 to help us today! Today we are going to learn about different ways that we can classify and identify rocks! Mr. Williams has given you the task of becoming rock experts. In order to do that, we need to review some skills for research which we learned about a few weeks ago. This should look familiar: ...

Andersen, Ms.

2010-11-13

283

Convective Weather Avoidance with Uncertain Weather Forecasts  

NASA Technical Reports Server (NTRS)

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 are likely to avoid. The automated system periodically updates forecasts and reassesses rerouting decisions in order to account for changing weather predictions. The main objectives are to reroute flights to avoid convective weather regions and determine the resulting complexity due to rerouting. The eventual goal is to control and reduce complexity while rerouting flights during the 20 minute - 2 hour planning period. A three-hour simulation is conducted using 4800 flights in the national airspace. The study compares several metrics against a baseline scenario using the same traffic and weather but with rerouting disabled. The results show that rerouting can have a negative impact on congestion in some sectors, as expected. The rerouting system provides accurate measurements of the resulting complexity in the congested sectors. Furthermore, although rerouting is performed only in the 20-minute - 2-hour range, it results in a 30% reduction in encounters with nowcast weather polygons (100% being the ideal for perfectly predictable and accurate weather). In the simulations, rerouting was performed for the 20-minute - 2-hour flight time horizon, and for the en-route segment of air traffic. The implementation uses CWAM, a set of polygons that represent probabilities of pilot deviation around weather. The algorithms were implemented in a software-based air traffic simulation system. Initial results of the system's performance and effectiveness were encouraging. Simulation results showed that when flights were rerouted in the 20-minute - 2-hour flight time horizon of air traffic, there were fewer weather encounters in the first 20 minutes than for flights that were not rerouted. Some preliminary results were also obtained that showed that rerouting will also increase complexity. More simulations will be conducted in order to report conclusive results on the effects of rerouting on complexity. Thus, the use of the 20-minute - 2-hour flight time horizon weather avoidance teniques performed in the simulation is expected to provide benefits for short-term weather avoidan

Karahan, Sinan; Windhorst, Robert D.

2009-01-01

284

Hydrochemistry, weathering and weathering rates on Madeira island  

NASA Astrophysics Data System (ADS)

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 ?S/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 sequence of Pl>Ol>Py, but such reverse order is not unique. On average, the annual weathering rates (in mol/(ha y vol% mineral)) are 44±19 (Pl), 29±14 (Ol) and 22±13 (Py).

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

2003-12-01

285

Deep weathering and alteration in granites - a product of coupled processes  

Microsoft Academic Search

Weathering and alternation in granite has a deep inpact on both geotechnical properties of the rock as well as of the rock mass. In a granite rock mass, the discontinuity pattern together with joint cohesion and friction plays a major role in tunnel construction and road cut slopes. These pheneomena and their cou-pling could be exclusively studied at the Königshainer

K. Thuro; M. Scholz

2004-01-01

286

Weathering Grade Classification of Granite Stone Monument Using Reflectance Spectroscopy  

NASA Astrophysics Data System (ADS)

Stone monument has been placed in field and exposed to rain and wind. This outdoor environment and air pollution induced weathering of stone monument. Weathering grade classification is necessary to manage and conserve stone monuments. Visual interpretation by geologist and laboratory experiments using specimens fallen off from the monument to avoid damage on the monument have been applied to classify weathering grade conventionally. Rocks and minerals absorb some particular wavelength ranges of electromagnetic energy by electronic process and vibrational process of composing elements and these phenomena produce intrinsic diagnostic spectral reflectance curve. Non-destructive technique for weathering degree assessment measures those diagnostic absorption features of weathering products and converts the depths of features related to abundance of the materials to relative weathering degree. We selected granite outcrop to apply conventional six folded weathering grade classification method using Schmidt hammer rebound teste. The correlations between Schmidt hammer rebound values and absorption depths of iron oxides such as ferric oxide in the vicinity of 0.9 micrometer wavelength and clay minerals such as illite and kaolinite in the vicinity of 2.2 micrometer wavelength, representative weathering products of granite, were analyzed. The Schmidt hammer rebound value decreased according to increase of absorption depths induced from those weathering products. Weathering grade classification on the granite stone monument was conducted by using absorption depths of weathering products This research is supported from National Research Institute of Cultural Heritage and we appreciate for this.

Hyun, C.; Roh, T.; Choi, M.; Park, H.

2009-05-01

287

WeatherHawk Weather Station Protocol  

NSDL National Science Digital Library

This resource provides instructions on how to log atmosphere data using a WeatherHawk weather station. A weather station is setup to measure and record atmospheric measurements at 15-minute intervals and can be transferred to the GLOBE program via email. Students can view data for their school that are continuous and show variations within a day. The data collected includes wind speed and direction and pressure thereby supporting a more complete study of meteorology using GLOBE. Students pursue a more extensive set of research investigations.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

288

Development of Rock Engineering  

NSDL National Science Digital Library

This chapter describes the development of rock engineering and provides introductory descriptions of the following concepts: rockbursts and elastic theory, discontinuous rock masses, engineering rock mechanics, geological data collection, laboratory testing of rock, rock mass classification, rock mass strength, in situ stress measurements, groundwater problems, rock reinforcement, excavation methods in rock, and analytical tools used in rock engineering.

2008-08-21

289

Fabulous Weather Day  

NSDL National Science Digital Library

Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. After studying weather for three months, we celebrate what we have learned and stretch our thinking further into the weather world around us! 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 their understanding of how the weather works and how it can affect their lives. Our unit focused on guiding students to formulate explanations about animals based on scientific evidence.

Marshall, Candice; Mogil, H. M.

2007-01-01

290

External Resource: Weathering and Erosion  

NSDL National Science Digital Library

This activity includes background information about weathering, as well as simple demonstrations/activities to model how weather conditions contribute to weathering and erosion. Topics include: chemical weathering, dunes, erosion, floods, glaciers, physi

1900-01-01

291

Plymouth State Weather Center  

NSDL National Science Digital Library

The Plymouth State Weather Center provides a variety of weather information, including a tropical weather menu with current and archived data on tropical depressions, storms, or hurricanes in the Atlantic or Eastern Pacific Oceans. An interactive Weather Product Generator allows students to make their own surface data maps and meteograms (24-hour summaries of weather at a specific location), and view satellite imagery. There are also interactive weather maps for the U.S., Canada, and Alaska that display the latest observations, and text servers which provide current written observations for New England and North America. A set of past and current weather data products provides information on minimum and maximum temperatures, wind chill, and heat index. In addition, there are collections of satellite loops/movies, radar/lightning images, loops, and movies, and a set of tutorials on clouds, the sun and its effects on the environment, and balanced atmospheric flows.

292

Avalanche Weather Forecasting  

NSDL National Science Digital Library

Avalanches form through the interaction of snowpack, terrain, and weather, the latter being the focus of this module. The module begins with basic information about avalanches, highlighting weather's role in their development. The rest of the module teaches weather forecasters how to make an avalanche weather forecast, that is, one in which key weather parameters are evaluated for their impact on avalanche potential. The forecasts are used primarily by avalanche forecasters, who integrate them with other information to determine when to issue avalanche hazard warnings. The module contains five cases that let users apply the avalanche weather forecast process to different combinations of snowpack, terrain, and weather conditions. It is a companion to the COMET module "Snowpack and Its Assessment," which describes snowpack development and various assessment techniques.

Linder, Dave

2011-01-01

293

Monitoring moisture dynamics in weathered, fractured bedrock  

NASA Astrophysics Data System (ADS)

Variably weathered, fractured bedrock underlying hillslopes influences runoff pathways, moisture availability, and slope stability yet direct measurement of moisture dynamics within this zone remains challenging. Established methods for monitoring moisture content in soils are not easily transferrable to fractured rock environments due to inaccessibility and the difficulties associated with the installation and calibration of sensors. At a steep, intensively instrumented hillslope in coastal northern California we explore 7 methods of varying spatial scale and temporal frequency to document moisture dynamics in weathered, fractured argillite bedrock. The forested 4000 m2 catchment is mantled by approximately 50 cm of soil and underlain by a thick weathered bedrock zone which extends to 25 m at the ridge top and thins downslope to a depth of 4 m. The Mediterranean climate at the site is characterized by cool, wet winters and warm, dry summers receiving most of the annual precipitation (1900 mm on average) between October and May. The following measurement methods are employed at the site: 1) downhole neutron moisture logging (CPN 503DR Hydroprobe) in 12 wells, 6-35 m deep 2) time domain reflectometer probes (TDR100, Campbell Scientific) installed in trenches and augured holes of varying backfill material 3) capacitance sensors (SM200, Dynamax, Inc) installed near the surface 4) electrical resistance sensor array systems (ERSAS) installed in augured and backfilled holes, 5) time lapse, non-invasive electrical resistivity tomography, 6) pressure transducers installed in deep wells and 7) laboratory gravimetric measurements of samples collected in augured holes and wells. Our observations highlight how each measurement method individually or collectively contributes to the understanding of moisture dynamics and runoff processes in fractured, weathered bedrock. We found that though backfill material and well casing significantly influence the magnitude of the measured response, using the timing of the response and manufacturer or site specific calibration, allowed us to effectively quantify moisture storage and transport rates in the weathered bedrock. We found that in response to rainfall, all water passes through the soil and weathered bedrock at the site and perches above the fresh bedrock before it travels laterally downslope. The rapid water table response to the first storm events of the season often occurs before the wetting front progresses through the first few meters of the weathered profile. Though shallower weathered bedrock wets and dries annually, deeper portions of the weathered bedrock zone do not show significant seasonal changes in moisture content. As investigations of the critical zone extend deeper, robust techniques for monitoring moisture in weathered bedrock are needed to quantify the significance of rock moisture in hydrologic and geomorphic processes.

Rempe, D. M.; Salve, R.; Oshun, J.; Dietrich, W. E.

2013-12-01

294

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

295

Geochemistry of Mesoproterozoic sedimentary rocks of upper Vindhyan Group, southeastern Rajasthan and implications for weathering history, composition and tectonic setting of continental crust in the northern part of Indian shield  

NASA Astrophysics Data System (ADS)

The upper Vindhyan succession of southeastern Rajasthan is divisible into Kaimur, Rewa and Bhander Groups. The major and trace element (including rare earth elements) data of the upper Vindhyan shales and sandstones are investigated to determine the weathering history, composition, and tectonic setting of Mesoproterozoic continental crust. CIA (chemical index of alteration) values, A-CN-K plot (A = Al2O3, CN = CaO* + Na2O, K = K2O) and depletion in U, Na2O, CaO, Sr and Ba suggest that the source area experienced moderate to high degree of chemical weathering under warm and humid conditions. Provenance modeling indicates that the Kaimur sandstones are best modeled with a mixture having 40% granitic gneiss, 20% Tonalite-Trondhjemite-Granodiorite (TTG), 20% mafic enclaves and 20% Berach Granite of the Banded Gneissic Complex (BGC). A mixture of 60% granitic gneiss, 20% mafic enclaves and 20% Berach Granite of the BGC can model the Rewa and Bhander Groups. It is suggested that the upper Vindhyan sedimentation commenced at the time of Delhi-Sausar orogeny at about 1100-1000 Ma. The orogenic movements uplifted the parts of old continental crust in the BGC terrain creating positive areas, which exposed older crustal blocks containing TTG as important component. The debris of Kaimur sandstone probably derived from these uplifted blocks. As indicated by Palaeocurrent data, the Rewa and Bhander formations were derived from Bundelkhand Granitic Gneiss Complex (BGGC) occurring to the north of the basin and/or the Chotanagpur Granitic Gneiss Complex (CGGC) of eastern Indian shield. The derivation of Lower and upper groups of Vindhyan succession from different source terrains of identical composition suggests that at the time of Vindhyan sedimentation, the BGC of Rajasthan, the BGGC of Central India and the CGGC of eastern India had similar lithological composition. This implies that well before the origin of the Vindhyan basin these discrete terrains evolved as a single unit that existed as a Mesoarchaean nucleus in the northern part of the Indian shield.

Raza, Mahshar; Khan, Abdullah; Bhardwaj, V. R.; Rais, Sarwar

2012-04-01

296

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

NASA Astrophysics Data System (ADS)

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 biogeochemical cycling process in the Mid-Oceanic Ridge setting.

Chen, Shun; Wu, Zijun; Peng, Xiaotong

2014-08-01

297

Igneous Rocks  

NSDL National Science Digital Library

This interactive Flash page provides information about the formation and crystallization of igneous rocks. It includes pictures and animations with supplementary information and is suitable for high school or introductory level undergraduate physical geology courses.

Smoothstone; Company, Houghton M.

298

Seafloor weathering buffering climate: numerical experiments  

NASA Astrophysics Data System (ADS)

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 reactions, carbonate precipitation, and clay formation.

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

2013-12-01

299

Weathering and morphogenesis in a mediterranean climate, Calabria, Italy  

NASA Astrophysics Data System (ADS)

Deeply weathered plutonic rocks occur widely in the Sila Massif, Calabria, southern Italy. Three representative weathering profiles developed on the hilltops indicate that sand represents more than 50% by weight throughout most of the weathering profile, and silt- and clay-size fractions are also well represented, filling the interstices among corestones. Both sand, and finer fractions of grus, and soil horizons, are thought to be derived from a combination of granular disintegration and chemical decomposition, developed on relatively flat terrains of the Sila massif. These slopes are now experiencing transport-limited morphodynamics, under a montane-modified Mediterranean climate. The depth of the weathered layers, that have suffered little erosional truncation, typically exceed 15 m, and may reach 50-60 m or more. Major isolated or grouped exfoliation boulders are the most common minor landform feature developed on the Sila massif granite. Boulders have developed as a result of spheroidal weathering and by removal of the sandy-textured granite. The Schmidt hammer (SH) test on boulders and corestones, suggests three distinctive degree of weathering (from moderately to completely weathered rock), and that biotite content is the major controlling factor of the granite mechanical behaviour. Understanding of the dynamics of this weathering system is crucial to the interpretation of the complex suite of variables that control landscape evolution of granitoid terrains.

Le Pera, Emilia; Sorriso-Valvo, Marino

2000-09-01

300

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

USGS Publications Warehouse

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.

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

2008-01-01

301

Weather and Atmosphere  

NSDL National Science Digital Library

In this unit, students learn the basics about weather and the atmosphere. They investigate materials engineering as it applies to weather and the choices available to us for clothing to counteract the effects of weather. Students have the opportunity to design and analyze combinations of materials for use in specific weather conditions. In the next lesson, students also are introduced to air masses and weather forecasting instrumentation and how engineers work to improve these instruments for atmospheric measurements on Earth and in space. Then, students learn the distinguishing features of the four main types of weather fronts that accompany high and low pressure air masses and how those fronts are depicted on a weather map. During this specific lesson, students learn different ways that engineers help with storm prediction, analysis and protection. In the final lesson, students consider how weather forecasting plays an important part in their daily lives by learning about the history of weather forecasting and how improvements in weather technology have saved lives by providing advance warning of natural disasters.

Integrated Teaching And Learning Program

302

Slake durability study of shaly rock and its predictions  

Microsoft Academic Search

More than 35% of the earth’s crust is comprised of clay-bearing rocks, characterized by a wide variation in engineering properties and their resistance to short term weathering by wetting and drying phenomenon. The resistance to short-term weathering can be determined by slake durability index test. There are various methods to determine the slake durability indices of weak rock. The effect

T. N. Singh; A. K. Verma; Vasudev Singh; A. Sahu

2005-01-01

303

Match Rock  

NSDL National Science Digital Library

In this activity, learners try to figure out who has their matching rock type by reading a description of their rock (no talking!). This activity can be used in a variety of ways: to introduce students to each other (icebreaker), to improve communication and writing skills, to introduce classification schemes and taxonomy, and to show how scientists use observations and descriptions to draw links between others' data and interpretations.

Muller, Eric

2003-01-01

304

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

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.

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

2009-01-01

305

NOAA Daily Weather Maps  

NSDL National Science Digital Library

The charts on this website are the principal charts of the former Weather Bureau publication, "Daily Weather Map." They are the Surface Weather Map, the 500-Millibar Height Contours chart, the Highest and Lowest Temperatures chart, and the Precipitation Areas and Amounts chart. For each day, simple charts are arranged on a single page. These charts are the surface analysis of pressure and fronts, color shading, in ten degree intervals,of maximum and minimum temperature, 500-Millibar height contours, and color shaded 24-hour total precipitation. These charts act as links to their respective Daily Weather Map charts. All charts are derived from the operational weather maps prepared at the National Centers for Environmental Prediction, Hydrometeorological Prediction Center, National Weather Service.

Center, Hydrometeorological P.

2011-01-01

306

Release of uranium decay-series nuclides from Florida phosphate rock  

Microsoft Academic Search

Studies are being conducted on Florida phosphate rock to help understand the release of natural decay-series radionuclides into associated groundwaters. The authors have analyzed all isotopes with half-lives longer than a few days in samples of both weathered and unweathered phosphate rock previously separated into seven size classes. Samples which have been subjected to intense weathering display higher specific activities

P. A. Chin; S. Deetae; W. C. Burnett

1985-01-01

307

Clay Mineral Formation and Transformation in Rocks and Soils  

Microsoft Academic Search

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

D. D. Eberl; V. C. Farmer; R. M. Barrer

1984-01-01

308

Weather and Climate Data  

NSDL National Science Digital Library

The Weather and Climate Data site for the Center for Ocean-Land-Atmosphere Studies (COLA) contains analyses of current conditions and the state of the atmosphere; weather forecasts; metropolitan quick-look weather summaries and meteograms; short-term climate outlooks for temperature, precipitation and soil moisture; El Nino forecasts for understanding the ocean-atmosphere system; and maximum potential hurricane intensity maps showing potential minimum pressure and potential maximum winds for the oceans.

309

Space Weather: Welcome, SEC  

NSDL National Science Digital Library

This video presentation welcomes the Space Environment Center (SEC) to the National Weather Service (NWS) as an operational entity of the National Centers for Environmental Prediction (NCEP) family. Describing the ways in which space weather affects global communications and power resources, it demonstrates the importance of space weather forecasting as a part of the NWS family of services. With the inclusion of SEC, the NWS now provides environmental understanding from the sun to the sea.

Spangler, Tim

2005-01-11

310

WWW - Wonderful Web Weather  

NSDL National Science Digital Library

This is a web quest for students to research weather forecasting using the Internet. Students work in groups to study how accurate weather forecasts are by tracking the weather for 3 days in several locations. Using graphs students then compare how each location scored in accuracy and present their findings to the class. This site contains links for students to use for more background information, a process for the students to follow, and evaluation rubrics for the student-produced graphs and presentation.

Parrish, Jason

311

RBSP Space Weather data  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

312

National Weather Service  

NSDL National Science Digital Library

Sick and tired of the heat? Feel like it will never end? Then check out the National Weather Service's (NWS) Heat Wave, a site devoted to the extreme weather that is crippling the south. The NWS provides information on the heat index, heat's affect on the body, and how to beat the heat. For those who want an up-to-the-minute look at the weather, the site links to current conditions, forecasts, and watches and warnings.

313

Backyard Weather Stations  

NSDL National Science Digital Library

Learn how to build your own backyard weather station with complete directions provided by FamilyEducation.com's Web site, Backyard Weather Stations. The site shows exactly what you'll need and how to build the necessary components (e.g., rain gauge and barometer), as well as how to keep records of the data collected. Parents and teachers will enjoy watching the kids "learn the basics of scientific observation and record-keeping while satisfying their natural curiosity about weather."

Randall, Dennis.

314

Winter weather activity  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather Maker Simulator Use the weather simulation above to answer the following questions in complete sentences on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there is high ...

Frankovic, Whitney

2009-09-28

315

Everything Weather- Archived Data  

NSDL National Science Digital Library

Users can obtain current weather forecasts for their own areas by entering a ZIP code, or they can access a large archive of historic data on severe weather (tornadoes, hail, high winds, hurricanes). Materials presented in the archive include dates, times, and intensities of storms, a photo gallery, maps, radar and other satellite data, storm chaser reports, and links to other weather sites. Raw data can be found in several forms for teachers wishing to have unprocessed data to work with.

2001-01-01

316

Weather and climate  

NASA Technical Reports Server (NTRS)

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.

1975-01-01

317

Weather or Not?  

NSDL National Science Digital Library

Weather or Not? is part of an online series of modules entitled Exploring the Environment. Emphasizing an integrated approach to environmental Earth Science education through problem-based learning, this module asks students to monitor the current weather and make predictions for up to a week. Using satellite imagery and monitoring resources, students predict the weather for an up-coming event of their choice (such as a sporting event). After the predictions are made, students track the actual weather that occurred during the event. There are links and resources for further information and research, as well as a reference on problem-based learning.

318

Weather assessment and forecasting  

NASA Technical Reports Server (NTRS)

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.

1977-01-01

319

Washington Post Weather  

NSDL National Science Digital Library

The Washington Post makes a bid for the already crowded Internet weather market with WeatherPost. Coverage includes current conditions and four-day forecasts for 3,600 cities worldwide, as well as snapshot and time-lapse satellite maps (provided by Accu Weather). For US cities, users may also access UV and air quality maps and data, as well as seasonal maps (snow cover, tanning index, heat index, and BeachCast) and other radar images such as precipitation. Users may enter a city name into the homepage search box, or may browse by country or state/province. The historical weather database offers compiled monthly average weather data for nearly 1,000 cities worldwide; the database is searchable. An aspect of the site that sets it apart from many other weather pages is the weather reference desk, which includes a weather glossary, weather calculators (JavaScript converters for temperature, wind chill, heat index, etc.) and a page devoted to storm chasers.

1997-01-01

320

Winter Storm (weather)  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? Form groups of THREE. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper... 1. In general, when are winds formed? 2. When winds are blowing, how can you ...

Miller, Aubree

2009-09-28

321

Weathering of sulfides on Mars  

NASA Technical Reports Server (NTRS)

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.

Burns, Roger G.; Fisher, Duncan S.

1987-01-01

322

Microcrack pattern propagations and Rock Quality Designation of Batu Caves Limestone  

Microsoft Academic Search

Microcrack pattern of limestone with various grade of natural weathering were studied to examine the microcrack initiation and propagations in relation to Rock Quality Designation (RQD) and shear strength parameters such as shear stress and normal stress. The degree of natural weathering were determined using Schmidt hammer test and it was found that as the weathering grade increased from grade

N I M Pauzi; H Omar; B K Huat; H Misran; Z M Yusoff

2011-01-01

323

'Wopmay' Rock  

NASA Technical Reports Server (NTRS)

This approximate true-color image taken by NASA's Mars Exploration Rover Opportunity shows an unusual, lumpy rock informally named 'Wopmay' on the lower slopes of 'Endurance Crater.' The rock was named after the Canadian bush pilot Wilfrid Reid 'Wop' May. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe the lumps in Wopmay may be related to cracking and alteration processes, possibly caused by exposure to water. The area between intersecting sets of cracks eroded in a way that created the lumpy appearance. Rover team members plan to drive Opportunity over to Wopmay for a closer look in coming sols. This image was taken by the rover's panoramic camera on sol 248 (Oct. 4, 2004), using its 750-, 530- and 480-nanometer filters.

2004-01-01

324

A visual analytical approach to rock art panel condition assessment  

NASA Astrophysics Data System (ADS)

Rock art is a term for pecked, scratched, or painted symbols found on rock surfaces, most typically joint faces called rock art panels. Because rock art exists on rock at the atmosphere interface, it is highly susceptible to the destructive processes of weathering. Thus, rock weathering scientists, including those that study both natural and cultural surfaces, play a key role towards understanding rock art longevity. The mapping of weathering forms on rock art panels serves as a basis from which to assess overall panel instability. This work examines fissures, case hardened surfaces, crumbly disintegration, and lichen. Knowledge of instability, as measured through these and other weathering forms, provides integral information to land managers and archaeological conservators required to prioritize panels for remedial action. The work is divided into five chapters, three of which are going to be submitted as a peer-reviewed journal manuscript. The second chapter, written as a manuscript for International Newsletter on Rock Art, describes a specific set of criteria that lead to the development of a mapping tool for weathering forms, called 'mapping weathering forms in three dimensions' (MapWeF). The third chapter, written as a manuscript for Remote Sensing of Environment, presents the methodology used to develop MapWeF. The chapter incorporates terrestrial laser scanning, a geographic information system (GIS), geovisualization, image analysis, and exploratory spatial data analysis (ESDA) to identify, map, and quantify weathering features known to cause instability on rock art panels. The methodology implemented in the third chapter satisfies the criteria described in Chapter Two. In the fourth chapter, prepared as a manuscript for Geomorphology, MapWeF is applied to a site management case study, focusing on a region---southeastern Colorado---with notoriously weak and endangered sandstone rock art panels. The final conclusions chapter describes contributions of the work to GIScience and rock weathering, and discusses how MapWeF, as a diagnostic tool, fits into a larger national vision by linking existing rock art stability characterizations to cultural resource management-related conservation action.

Vogt, Brandon J.

325

Erosion and the rocks of Venus  

NASA Technical Reports Server (NTRS)

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.

Sagan, C.

1976-01-01

326

Mild and Wild Weather.  

ERIC Educational Resources Information Center

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)

NatureScope, 1985

1985-01-01

327

People and Weather.  

ERIC Educational Resources Information Center

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)

NatureScope, 1985

1985-01-01

328

Basics of Weather Models.  

National Technical Information Service (NTIS)

Without using mathematics, this memo summarizes the important information weather forecasters need to know to apply numerical weather prediction (NWP) forecasts. We've had to make some tough choices regarding what material to include. We've put the more t...

W. D. Meyer

1993-01-01

329

Home Weatherization Visit  

ScienceCinema

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.

330

Home Weatherization Visit  

ScienceCinema

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.

Chu, Steven

2013-05-29

331

Northwest Weather Watch  

NSDL National Science Digital Library

This educational module is designed to teach students about predicting weather. This includes a series of activites about clouds, moisture, air and rain for students to complete. There are curriculum connections to art, writing and math as well as links for more resources and live weather data.

Palewicz, Sue; Scurlock, Marianne; Edmon, Harry

332

On Observing the Weather  

ERIC Educational Resources Information Center

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…

Crane, Peter

2004-01-01

333

Weathering Database Technology  

ERIC Educational Resources Information Center

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…

Snyder, Robert

2005-01-01

334

Fabulous Weather Day  

ERIC Educational Resources Information Center

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…

Marshall, Candice; Mogil, H. Michael

2007-01-01

335

Weather Fundamentals: Wind. [Videotape].  

ERIC Educational Resources Information Center

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…

1998

336

Weather Vane and Anemometer  

NSDL National Science Digital Library

In this meteorology activity, learners construct simple devices to measure the direction and speed of wind. Learners will explore wind and air resistance as well as how weather vanes and generators work to analyze weather patterns. Note: a drill and other specialty tools are required for this activity, but are not included in the cost of materials.

Workshop, Watsonville E.

2011-01-01

337

Erosion and Weathering  

NSDL National Science Digital Library

Weathering and erosion work together as natural forces, removing and transporting material. Sediments, the by-products of these processes, are subsequently deposited to produce characteristic landforms such as dunes, deltas, and glacial moraines. This slide show presents images of landforms that result from erosion and weathering, as well as measures designed to mitigate their unwanted effects.

338

Aviation Weather Program (AWP)  

NASA Technical Reports Server (NTRS)

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.

Foote, Brant

1993-01-01

339

Weathering of Serpentine Aggregates.  

National Technical Information Service (NTIS)

This report deals with the rapid weathering of serpentine aggregates in an autoclave-type device. Samples of serpentine aggregate from three sources were subjected to ten weathering cycles each and the results were compared with the resistance to rapid we...

1965-01-01

340

Benign Weather Modification.  

National Technical Information Service (NTIS)

Weather modification is a technology once embraced by the United States (US) military as a tool to help both wartime and peacetime missions. However, interest in the ability to modify weather has waned over recent years and is now nearly nonexistent. This...

B. B. Coble

1997-01-01

341

Benign Weather Modification.  

National Technical Information Service (NTIS)

Weather modification is a technology once embraced by the U.S. military as a tool to help both wartime and peacetime missions. However, interest in the ability to modify weather has waned over recent years and is now nearly non-existent. This study examin...

B. E. Coble

1996-01-01

342

Hydrologic regulation of chemical weathering and the geologic carbon cycle.  

PubMed

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

Maher, K; Chamberlain, C P

2014-03-28

343

The Schmidt hammer in rock material characterization  

Microsoft Academic Search

The Schmidt hammer provides a quick and inexpensive measure of surface hardness that is widely used for estimating the mechanical properties of rock material. However, a number of issues such as hammer type, normalization of rebound values, specimen dimensions, surface smoothness, weathering and moisture content, and testing, data reduction and analysis procedures continue to influence the consistency and reliability of

A. Aydin; A. Basu

2005-01-01

344

Chemical kinetics of water-rock interactions  

Microsoft Academic Search

The recent literature on the kinetics of water-rock interactions is reviewed. The data are then extended to provide a quantitative framework for the description of weathering and alteration. The available experimental data on dissolution of silicates verifies quantitatively the usual mineral stability series in sedimentary petrology. The rate of hydration of carbonic acid is shown to be a possible limiting

Antonio C. Lasaga

1984-01-01

345

Fair weather atmospheric electricity  

NASA Astrophysics Data System (ADS)

Not long after Franklin's iconic studies, an atmospheric electric field was discovered in "fair weather" regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

Harrison, R. G.

2011-06-01

346

Scholastic: Weather Watch  

NSDL National Science Digital Library

The Weather Watch series of online projects investigates seasonal weather phenomena. Students discover the scientific explanations for these events, and use tools and resources for enhanced research. The Hurricanes project allows students to monitor patterns and plot the progression of hurricanes. The Winter Storms project contains an interactive weather maker allowing students to create different weather patterns by changing factors. A winter storm timeline provides stories of the harshest blizzards that have occurred in the U.S. The Weather Reporters project includes a selection of hands-on science experiments for classroom participation, leading up to sharing results online with students worldwide. Each project provides assessment tools and lesson plan suggestions for educators. Links are provided for additional resources.

347

Predicting the Weather  

NSDL National Science Digital Library

This Topic in Depth explores the science behind predicting the weather. First, the United States Search and Rescue Task Force describe the basic tools and knowledge used to create weather forecasts (1). Students can find concise, clear explanations of weather, fronts and air masses, high and low pressure, precipitation, and water vapor and humidity as well. By performing the activities presented in the second website, fourth grade students can learn about weather instruments and data collection (2). This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Third, Edheads offers a Macromedia Flash Player enhanced interactive module allowing students to predict the weather by examining weather maps (3 ). Through this website, users can become familiar with the concepts of warm and cold fronts, wind direction and speed, air pressure, and humidity. The fourth website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather (4). Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Next, NOAA provides graphics for five forecast models: the ETA, the Global Forecast System (GFS), the Wave Watch III (WW3), the Nested Grid model (NGM), and the Rapid Update Cycle (RUC) (5). Outputs are available for North America, North Pacific, Western North Atlantic, and the Polar Ice Drift. Users can find links to detailed descriptions of the inputs and history of each model. Sixth, the British government's Met Office describes numerical modeling and its components (6). Students and educators can learn about the future in forecasting as well as educational opportunities with the Cooperative Program for Meteorology, Education, and Training (COMET).

348

Research Rocks  

USGS Multimedia Gallery

Dr. Alex Andronikov, a geologist from the University of Michigan Department of Geological Science, and Kelley Brumley, a geologist from Stanford University, sort through rocks that were dredged from the Arctic Ocean floor Sept. 9, 2009, aboard the Coast Guard Cutter Healy.The dredging is part of the...

2010-02-19

349

Rock Paintings.  

ERIC Educational Resources Information Center

Discusses the integration of art and academics in a fifth-grade instructional unit on Native American culture. Describes how students studied Native American pictographs, designed their own pictographs, made their own tools, and created rock paintings of their pictographs using these tools. Provides a list of references on Native American…

Jones, Julienne Edwards

1998-01-01

350

Rock Groups  

NSDL National Science Digital Library

In this one-page article Steven Strogatz explains how representing numbers with concrete objects can make calculations less confusing. By using images of rocks, he demystifies concepts such as square numbers, parity, primes, and sums of consecutive numbers. This is the second in Steven's series of 15 articles on the Elements of Math (home page cataloged separately).

Strogatz, Steven

2010-02-07

351

Stillwater Rocks  

USGS Multimedia Gallery

Rocks from the Stillwater Mine are brought to the USGS in Denver, Colorado, where they are ground before entering the plasma melter at Zybek Advanced Products. __________ The USGS has created man-made moon dirt, or regolith, to help NASA prepare for upcoming moon explorations. Four tons of the sim...

2009-05-26

352

Rock Grinding  

USGS Multimedia Gallery

Rocks from the Stillwater Mine are brought to the USGS in Denver, Colorado, where they are sledged and ground before entering the plasma melter at Zybek Advanced Products. __________ The USGS has created man-made moon dirt, or regolith, to help NASA prepare for upcoming moon explorations. Four ton...

2009-05-26

353

Analysis of Preflight Weather Briefings.  

National Technical Information Service (NTIS)

Weather is often cited as a factor in general aviation (GA) accidents and mishaps. The type of weather information requested from, or provided by, automated flight service station (AFSS) specialists is dependent on weather conditions at the time the prefl...

A. M. Hendrix O. V. Prinzo R. Hendrix

2007-01-01

354

Hypothermia: A Cold Weather Hazard  

MedlinePLUS

... cold air. But, not everyone knows that cold weather can also lower the temperature inside your body. ... cold it is where you are. Check the weather forecasts for windy and cold weather. Try to ...

355

Space Weather CD  

NSDL National Science Digital Library

This is a software package about space weather: what it is and what it does in space and here on Earth. The disc includes software that displays movies and images of the aurora and of the Sun in various wavelengths from the ground and from orbiting NASA spacecraft; a tutorial about what space weather is and how the aurora is formed; and more. Users will also find real-time space weather conditions from current satellite missions and can download the latest data without leaving the Space Weather application. A TicTacToe game is also included that tests space weather knowledge. The disc contains many other Space Weather resources, programs, sounds, and games for use at home or school, and there are several educational websites included in full on the disc for offline viewing. In addition there is an exhaustive list of links to a variety of space weather resources available online. The disc is available for free from a number of sites if downloaded.

356

Mechanics of Sheeting Joints and Spheroidal Weathering (Invited)  

NASA Astrophysics Data System (ADS)

Physical weathering in low-porosity materials, like most crystalline rocks, commonly involves fracture, which increases the surface area that can be accessed by reactive chemicals. Chemical reactions on these surfaces can in turn affect the course of further fracturing. Physical and chemical weathering thus commonly go hand in hand, although one process can dominate the other. Two common products of physical weathering are sheeting joints and spheroidal weathering. Both involve fracturing parallel or subparallel to a nearby surface, but they are distinctly different in several ways. Sheeting joints can achieve dimensions of a couple of hundred meters, typically have radii of curvature of 100m - 1000m, and are bounded on one side by the topographic surface. As the distance from the topographic surface increases, the spacing between sheeting joints generally increases and they become less curved. Neither chemical weathering nor grain-scale effects appear to be consequential in the formation of sheeting joints. In contrast, for spheroidal weathering the individual fractures are roughly grain-sized, form in “shells” with radii of curvature of about 1m, and are bounded on all sides by pre-existing bedrock fractures. As the distance from the bounding surfaces increases, the spacing between fractures generally stays about the same but the “shells” defined by the fractures become more curved. Both chemical weathering and grain-scale cracking accompany spheroidal weathering. The processes of sheeting joint formation and spheroidal weathering have been approached from the perspective of a complete boundary value problem in continuum mechanics, where several factors generally are needed to predict the physical failure of a rock mass, including: (a) the shape of a rock body; (b) the stresses acting on its surface, (c) the body forces within it, and (d) the equations of equilibrium; and (e) the constitutive laws for the material. In the cases of sheeting joint formation and spheroidal weathering, a simpler approach that depends on only four factors can be used to provide insight into the fracture process: (a) the shape of a rock body; (b) the stress distribution parallel to its surface, (c) the body forces within it, and (d) a single equation of equilibrium. This approach indicates that in both cases high compressive stresses parallel to convex bounding surfaces contribute fundamentally to the formation of the fractures. In at least some cases involving sheeting joints, the origin of these stresses is likely to be tectonic. In the case of spheroidal weathering, the compressive stresses are likely to arise from chemical alteration of grains.

Martel, S. J.

2010-12-01

357

Rock Classification and Rock Property Listing.  

National Technical Information Service (NTIS)

The Bureau of Mines conducted a project for the Advanced Research Projects Agency (ARPA) Rock Mechanics and Rapid Excavation program to investigate rock classification as one means to improve rapid excavation technology. A standard rock suite was establis...

W. W. Krech

1973-01-01

358

Weathering and Erosion  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses weather conditions and their contribution to weathering and erosion. Students learn to explain the process of physical and chemical weathering. They also learn to compare and contrast erosion resulting from wind, ice and water. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

359

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based Real Time Data Module was created by the Center for Improved Engineering and Science Education (CIESE) for use by students in the elementary grades to allow them to investigate weather phenomena both locally as well as in other places around the world. By using hands-on activities and real-time data investigations, the students will develop a basic understanding of how weather can be described in measurable quantities, such as temperature, wind and precipitation. The site features a Teacher Area containing lesson plans, curriculum standards, guidelines for data collection, and a list of children's books with weather-related themes.

360

Weather and Climate  

NSDL National Science Digital Library

This site features visual resources and supporting data that illustrate the relationship between weather and climate. Resources are divided by topic including climate resources, weather forecasting, warnings and data, and evidence for global warming. Visualizations and data sets include GIS-based animated maps, static maps, simple animations, and links to real-time stream gauge data. This site provides an array of visual resources that help demonstrate the difference between weather and climate and may be incorporated into lectures, labs, or other activities.

2007-04-11

361

Extreme Weather Sourcebook 2001  

NSDL National Science Digital Library

Originally reviewed in the February 26, 1999 Scout Report, the latest version of the National Center for Atmospheric Research (NCAR) Extreme Weather Sourcebook offers easy access to updated data on the economic damage from hurricanes, floods, and tornadoes in the United States and its territories. Time spans for each type of extreme weather vary, with hurricane data covering 1900-99, tornadoes 1950-99, floods 1955-1999, and lightning 1959-1994; however, all damage data are reported in constant 1999 dollars to simplify comparisons. The data are offered by weather event and state by rank or alphabetically.

2001-01-01

362

Wonderful World of Weather  

NSDL National Science Digital Library

This website uses real time data for many activities for learning about the weather. It can be modified to fit virtually any grade level. The project is broken up into 3 sets of lessons; Introductory Activities, Real Time Data Activities, and Language Arts Activities. Each lesson gives a recommended time for completion, to help keep students and teachers on track. There is a helpful teachers guide section with background information about real time data, curriculum standards, and assessment suggestions. Th students gallery has many examples of real projects other students have already created. There is also a helpful reference guide, with information on real time weather, projects, and weather lesson plans.

2006-01-01

363

Solar structure and terrestrial weather  

NASA Technical Reports Server (NTRS)

The possibility that solar activity has discernible effects on terrestrial weather is considered. Research involving correlation of weather conditions with solar and geomagnetic activity is discussed.

Wilcox, J. M.

1976-01-01

364

Release of biodegradable dissolved organic matter from ancient sedimentary rocks  

NASA Astrophysics Data System (ADS)

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.

Schillawski, Sarah; Petsch, Steven

2008-09-01

365

Meridiani Rocks  

NASA Technical Reports Server (NTRS)

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

2005-01-01

366

White Rock  

NASA Technical Reports Server (NTRS)

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

2005-01-01

367

White Rock  

NASA Technical Reports Server (NTRS)

(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't see . . . things like information about what kinds of minerals make up the landforms. Mars scientists once thought, for instance, that these unusual features might be vast hills of salt, the dried up remains of a long-ago, evaporated lake. Not so, said an instrument on the Mars Global Surveyor spacecraft, which revealed that the bright material is probably made up of volcanic ash or windblown dust instead. And talk about a cyclical 'ashes to ashes, dust to dust' story! Particles of this material fell and fell until they built up quite a sedimentary deposit, which was then only eroded away again by the wind over time, leaving the spiky terrain seen today. It looks white, but its apparent brightness arises from the fact that the surrounding material is so dark. Of course, good eyesight always helps in understanding. A camera on Mars Global Surveyor with close-up capabilities revealed that sand dunes are responsible for the smudgy dark material in the bright sediment and around it. But that's not all. The THEMIS camera on the Mars Odyssey spacecraft that took this image reveals that this ashy or dusty deposit once covered a much larger area than it does today. Look yourself for two small dots of white material on the floor of a small crater nearby (center right in this image). They preserve a record that this bright deposit once reached much farther. Since so little of it remains, you can figure that the material probably isn't very hard, and simply blows away. One thing's for sure. No one looking at this image could ever think that Mars is a boring place. With all of its bright and dark contrasts, this picture would be perfect for anyone who loves Ansel Adams and his black-and-white photography.

2002-01-01

368

Drainage basin weathering and major element transport of two large Chinese rivers (Huanghe and Changjiang)  

Microsoft Academic Search

Long-term records show high concentrations of dissolved major elements in the Changjiang (Yangtze River) and the Huanghe (Yellow River). The Huanghe drainage basin is characterized by intense weathering and erosion of carbonates and evaporites, while weathering and erosion of carbonates and silicates over the drainage basin is the main source of major elements in the Changjiang. The rock\\/soil composition and

Jing Zhang; Wei Wen Huang; Min Guang Liu; Qing Zhou

1990-01-01

369

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

Microsoft Academic Search

Models for the evolution of sulfide minerals on Mars and reaction pathways to their oxidative weathering products in Martian regolith have been proposed based on petrogenetic associations between komatiitic rock types, Viking geochemical data, SNC meteorites, and terrestrial Fe-Ni sulfide deposits. To test the weathering model, komatiitic pyrrhotites and olivines were exposed to sulfuric acid solutions, with and without dissolved

Roger G. Burns; Duncan S. Fisher

1990-01-01

370

Spatially variable erodability in bedrock channels produced by weathering  

Microsoft Academic Search

Erosion of bedrock-floored channels regulates the evolution of many landscapes, and accurate prediction of channel erosion rates is a primary goal of landscape evolution modeling. We hypothesize that bedrock weathering, typically neglected in models of bedrock channel evolution, introduces spatial variation in the rock erodability across such channels. The variability of erodability, in turn, may influence the equilibrium cross-sectional form

B. Murphy; G. S. Hancock; E. E. Small

2009-01-01

371

Release and transport of radium during weathering in central and north Florida  

Microsoft Academic Search

Samples of fresh and weathered Florida phosphate rock were analyzed for several uranium decay-series radionuclides. In bulk samples, almost all radionuclides display higher activities in weathered samples compared to fresh material. ²³°Th is normally in isotopic equilibrium with ²³⁴U in fresh material but often depleted and occasionally enriched in highly weathered samples. ²²⁶Ra is close to equilibrium with its parent

Deetae

1986-01-01

372

The coupling of biological iron cycling and mineral weathering during saprolite formation, Luquillo Mountains, Puerto Rico  

Microsoft Academic Search

Corestones of quartz diorite bedrock in the Rio Icacos watershed in Puerto Rico weather spheroidally to form concentric sets of partially weathered rock layers (referred to here as rindlets ) that slowly transform to saprolite. The rindlet zone (0.2-2 m thick) is overlain by saprolite (2-8 m) topped by soil (0.5-1 m). With the objective of understanding interactions between weathering,

H. L. BUSS; M. A. BRUNS; M. J. SCHULTZ; J. MOORE; C. F. MATHUR; S. L. BRANTLEY

2006-01-01

373

The use of the durometer to measure rock hardness in geomorphology. Advantages and limitations  

Microsoft Academic Search

The durometer is a hardness tester developed to measure hardness of metallic materials that has been recently introduced to measure rock hardness in weathering studies. Aoki & Matsukura (2007) highlight some advantages of the durometer compared with the Schmidt Rock Test Hammer: the smaller plunge allows measurements in small surfaces such as taffoni or rock carvings, the wider measurement range

Alejandra Feal-Pérez; Ramón Blanco-Chao; Marcos Valcarcel-Díaz; Martín. A. Combes

2010-01-01

374

Tombstone Weathering Lab  

NSDL National Science Digital Library

Students work in groups in a cemetery to collect a quantitative and a qualitative measure of the extent of weathering of tombstones and their ages. The data are shared between all students, graphed as scatter plots, and the rate of weathering is estimated. Students write about and then discuss the results, the difference between the quantitative and qualitative measures, and speculate on factors in addition to time that may be important for weathering rate. The exercise ends with each students writing a hypothesis about a factor that influences weathering rate and describing a research project that could test that hypothesis. This activity is aimed at developing an understanding of the scatter in "real data", allowing for practice of team work, and hypothesis generation and testing. Designed for a geomorphology course Has minimal/no quantitative component

Anders, Alison

375

Wasatch Weather Modification Project.  

National Technical Information Service (NTIS)

The primary objective of the Wasatch Weather Modification Project is to 'assess the relative effectiveness and the practicability of selected procedures for increasing the water supply, from precipitation in the Wasatch Mountains, by cloud seeding.' A loc...

G. W. Reynolds

1969-01-01

376

Cold-Weather Sports  

MedlinePLUS

Ahh, winter! Shorter days. Frigid temperatures. Foul weather. What better time to be outdoors? Winter sports can help you burn calories, increase your cardiovascular fitness, and strengthen muscles. Activities that are ...

377

Weather and Climate.  

National Technical Information Service (NTIS)

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 lo...

1975-01-01

378

Garments, Outer (Wet Weather).  

National Technical Information Service (NTIS)

The report describes a method for evaluation of wet weather clothing operational and functional performance characteristics. Identifies supporting tests, facilities, and equipment required. Provides procedures for preoperational inspection, physical chara...

R. Rush

1972-01-01

379

Cold Weather Aerostat Study.  

National Technical Information Service (NTIS)

Aerostats are being considered for application in cold weather regions. A review of aerostat flight experience to date was made to determine the limitations of the current technology. Areas for improvements and modifications to extend the aerostat system ...

R. L. Ashford

1982-01-01

380

Microclimatic factors controlling tafoni weathering in Tafraoute, Morocco  

NASA Astrophysics Data System (ADS)

Cavernous tafoni-type weathering is observed in many arid and semiarid regions of the world and the underlying processes, as well as the respective weathering rates, are still not fully understood. Although the conditions of Tafoni formation has been under consideration for approx. 100 years, there is still no unifom view about their formation process. Their distribution pattern is thought to be controlled by distance to shore, duration of the arid season, local fault systems or by the age of the respective exposure. Three possible ways of tafoni genesis are under discussion: (1) mechanical weathering by temperature and volume fluctuations in short periods which are reinforced by micro-circulation of air in the cavities; (2) mechanical weathering by hydration of salts; (3) chemical weathering including case hardening on the surface and "core weathering" of the interior. To understand the tafoni weathering process it boils down to three significant influential factors: temperature fluctuations, rock moisture and salt distribution. Our study focuses on tafoni weathering in Tafraoute, Morocco, located in the granites of the Kerdouse Massif. We attempt to clarify the formation process using a combination of various micro-climatic and geophysical methods. The most important technique is small-scale 2D-resistivity profiling which allows to look some decimetres inside the rock and to visualise rock moisture and salt concentration patterns. First morphometric analysis and mappings have been conducted in summer 2013, and micro-climatic investigations are carried out in February 2014. Mapping results show that tafoni distribution is influenced by topography and aspect. However, no relation between exposure and depth of the hollows was found; e.g. no significant differences in morphometric parameters were observed between northern and western rock faces. Temperature sensors were installed at different expositions and depths to measure daily temperature changes. These are supplemented by infrared images used to detect subtle spatio-temporal changes in surface temperature. The spatial distribution of rock moisture is derived from the aforementioned 2D-geoelectric profiles which have not been aplied in this context before. The geophysical measurements are complemented by capacitive handheld sensor surveys and borehole humidity measurements. Salt content is determined in a narrow grid using paper pulp poultices; the samples are analyzed in the laboratory for salt types and concentration. The investigations will contribute to understanding the importance of local- and microclimatic conditions, rock parameters and salt concentrations on the occurrence and shape of tafoni.

Fruhmann, Stefanie; Schnepfleitner, Harald; Sass, Oliver

2014-05-01

381

Weather Here and There  

NSDL National Science Digital Library

The Global Education Project of the Resource for Science Education Program offers the Weather Here and There educational unit. The Web site consists of six lessons geared for students in grades four through six that cover everything from characteristics of the Earth's atmosphere to forecasting the weather. Each lesson contains the objectives, materials, background information, vocabulary, evaluation, etc. needed to easily prepare and complete each.

1995-01-01

382

Windows on the Weather  

NASA Astrophysics Data System (ADS)

Windows on the Weather is a web-based teaching tool designed to engage middle school students in the analysis and understanding of Earth's atmosphere by combining current weather satellite imagery with live webcams from across the United States. This project lends itself to inquiry-based studies in a variety of Earth science disciplines, including meteorology, climatology, and geography. This paper describes the project as it currently stands, along with features to be implemented in the future.

Alena, T. R.

2010-08-01

383

NOAA Weather Education  

NSDL National Science Digital Library

NOAA offers links to a variety of educational materials on meteorology, hydrology, climatology, and other weather-related fields for children, teens, and young adults at this website. Students can find websites where they can learn about hurricanes, storms, tornadoes, and floods through interactive games. Teachers can find lightning safety presentations, satellite images, lightning photos, and glossaries. The website offers materials on weather related careers, degree programs, distance learning courses, and additional opportunities.

384

TypoWeather  

NSDL National Science Digital Library

The TypoWeather application is a great way to stay on top of the latest weather conditions. This handy device presents users with a five day outlook and an hourly breakdown that is updated based on data from the National Meteorological Service. Visitors can customize their layout to include alerts about certain meteorological conditions, such as wind patterns, humidity, and more. This version is compatible with all operating systems.

2014-03-13

385

Extreme Weather Sourcebook: Tornadoes  

NSDL National Science Digital Library

The Extreme Weather Sourcebook is a database maintained by the Societal Impacts Program (SIP) at NCAR of statistics on extreme weather events. The Sourcebook is intended as a resource for researchers, policy makers, the media, and the general public, among other users. This page from the Sourcebook showcases data on tornado damages as total losses for the years 1950-2009 in the United States.

University Consortium for Atmospheric Research (UCAR)

386

Radiogenic Isotopes in Weathering and Hydrology  

NASA Astrophysics Data System (ADS)

There are a small group of elements that display variations in their isotopic composition, resulting from radioactive decay within minerals over geological timescales. These isotopic variations provide natural fingerprints of rock-water interactions and have been widely utilized in studies of weathering and hydrology. The isotopic systems that have been applied in such studies are dictated by the limited number of radioactive parent-daughter nuclide pairs with half-lives and isotopic abundances that result in measurable differences in daughter isotope ratios among common rocks and minerals. Prior to their application to studies of weathering and hydrology, each of these isotopic systems was utilized in geochronology and petrology. As in the case of their original introduction into geochronology and petrology, isotopic systems with the highest concentrations of daughter isotopes in common rocks and minerals and systems with the largest observed isotopic variations were introduced first and have made the largest impact on our understanding of weathering and hydrologic processes. Although radiogenic isotopes have helped elucidate many important aspects of weathering and hydrology, it is important to note that in almost every case that will be discussed in this chapter, our fundamental understanding of these topics came from studies of variations in the concentrations of major cations and anions. This chapter is a "tools chapter" and thus it will highlight applications of radiogenic isotopes that have added additional insight into a wide spectrum of research areas that are summarized in almost all of the other chapters of this volume.The first applications of radiogenic isotopes to weathering processes were based on studies that sought to understand the effects of chemical weathering on the geochronology of whole-rock samples and geochronologically important minerals (Goldich and Gast, 1966; Dasch, 1969; Blaxland, 1974; Clauer, 1979, 1981; Clauer et al., 1982); as well as on the observation that radiogenic isotopes are sometimes preferentially released compared to nonradiogenic isotopes of the same element during acid leaching of rocks ( Hart and Tilton, 1966; Silver et al., 1984; Erel et al., 1991). A major finding of these investigations was that weathering often results in anomalously young Rb-Sr isochron ages, and discordant Pb-Pb ages. Rubidium is generally retained relative to strontium in whole-rock samples, and in some cases radiogenic strontium and lead are lost preferentially to common strontium and lead from weathered minerals.The most widely utilized of these isotopic systems is Rb-Sr, followed by U-Pb. The K-Ar system is not directly applicable to most studies of rock-water interaction, because argon is a noble gas, and upon release during mineral weathering mixes with atmospheric argon, limiting its usefulness as a tracer in most weathering applications. Argon and other noble gas isotopes have, however, found important applications in hydrology (see Chapter 5.15). Three other isotopic systems commonly used in geochronology and petrology include Sm-Nd, Lu-Hf, and Re-Os. These parent and daughter elements are in very low abundance and concentrated in trace mineral phases. Sm-Nd, Lu-Hf, and Re-Os have been used in a few weathering studies but have not been utilized extensively in investigations of weathering and hydrology.The decay of 87Rb to 87Sr has a half-life of 48.8 Gyr, and this radioactive decay results in natural variability in the 87Sr/86Sr ratio in rubidium-bearing minerals (e.g., Blum, 1995). The trace elements rubidium and strontium are geochemically similar to the major elements potassium and calcium, respectively. Therefore, minerals with high K/Ca ratios develop high 87Sr/86Sr ratios over geologic timescales. Once released into the hydrosphere, strontium retains its isotopic composition without significant fractionation by geochemical or biological processes, and is therefore a good tracer for sources and cycling of calcium. The decay of 235U to 207Pb, 238U to 206Pb, and 232Th to 208Pb hav

Blum, J. D.; Erel, Y.

2003-12-01

387

Mineralogy of Natural Basalt Weathering Rinds With Application to Thermal Emission Spectra of Mars  

NASA Astrophysics Data System (ADS)

Mineralogy of Natural Basalt Weathering Rinds With Application to Thermal Emission Spectra of Mars M.D. Kraft, J.R. Michalski, T.G. Sharp, (and P.R. Christensen?) Chemically weathered rocks have been suggested to cover a significant portion of the Martian surface based on orbiter observations, and rocks investigated by the Mars Exploration Rover at the Gusev landing site show evidence of chemical alteration and weathering rinds. To understand remote mineralogical and chemical measurements of altered rock surfaces, whether in situ or from orbit, it is important to understand the general characteristics of weathering rinds (e.g., secondary mineralogy and microstructure in rinds) and how these characteristics affect remote observations. We are investigating a suite of weathered rocks of the Columbia River Basalt Group (CRBG) to identify chemical, mineralogical, and micro-structural changes associated with weathering and determine how these changes influence thermal emission measurements. Preliminary work shows that thermal emission spectra of weathered surfaces can vary substantially from spectra of fresh rocks despite rather low degrees of alteration in weathered surfaces. In rocks studied thus far, the predominant difference between the unweathered rock and weathering rind is an increase in porosity in the rind due to dissolution and/or volume expansion, causing a substantial increase in the volume density of micron-scale cracks. Mineralogical differences are imparted in the rind by the (partial) infilling of cracks by secondary materials that are Si, Al, and Fe-rich. A previous investigation by Colman (1982) showed that secondary silicates in basalt weathering rinds were dominantly X-ray amorphous. High-resolution secondary electron imaging of crack-filling products reveals spheroid-shaped materials, 10s of nm in diameter, which are consistent with short-range order allophane. We are currently performing additional analyses using XRD and TEM to constrain the mineralogy of secondary phases in CRGB weathering rinds, including the crystallinity of secondary silicates. Assessing chemical weathering on Mars may rely largely on the ability to detect and constrain the mineralogy of short-range order silicates, which may be the dominant Martian weathering products. Thermal emission spectroscopic data of Mars, with the detailed understanding that we intend to provide with this study, provides a unique and excellent means of constraining the nature of silicate weathering on Mars.

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

2004-12-01

388

Weathering of granodioritic crust, long-term storage of elements in weathering profiles, and petrogenesis of siliciclastic sediments  

NASA Astrophysics Data System (ADS)

The bulk composition and mineralogy of the Toorongo Granodiorite, Australia, are similar to average upper continental crust (AUCC). Weathering characteristics of the Toorongo profile consequently provide insight into large-scale chemical weathering of the upper crust. In situ weathered materials of the profile do not reflect parent granodiorite composition in quartz-plagioclase-K-feldspar (Q-P-K) or in quartz-feldspar-rock fragment (Q-F-L) compositional space. Intensive in situ weathering precludes sands, derived from mature weathering profiles through erosion, from reflecting their provenance. Where intensive chemical weathering has occurred, clay minerals and oxyhydroxides of the profile, and by inference muds derived therefrom, contain much more chemical information about provenance than do associated sands. Actinides, rare earth elements (REEs), many transition metals, and metalloids have accumulated in deep parts of the weathering profile at concentrations much greater than observed in the fresh granodiorite. Mass balance considerations require the bulk of these elements to have been derived from previously weathered, and now eroded, granodiorite. These elements were, and are, continually cycled from the intensely weathered uppermost soil zone to deeper, less weathered, zones of the profile where they accumulate. The profile therefore represents a large, continental elemental storage reservoir, the storage capacity of which has increased over time. Wherever erosion is sufficiently slow and chemical weathering sufficiently rapid, mature weathering profiles may become large, long-term storage reservoirs for actinides, REEs, and many other elements. The total REE contents of extremely weathered soil material are somewhat less than in the parent granodiorite, but they are enriched twofold to threefold in the zone of intermediate weathering relative to parent. Similar variations in total REEs are observed in some muds when normalized to their source (AUCC). These differences are attributed to a combination of chemical weathering and selective mass wasting of profiles. Homogenization of detritus in large sedimentary basins, however, produces muds with REE patterns and total REE contents similar to source (AUCC). Nd/Sm ratios are not influenced by chemical weathering, although both elements are mobilized by weathering and become enriched by over 200% relative to parent rock. Constancy of Nd/Sm in the profile indicates that Nd-Sm model ages derived from soils and sediments are not affected by chemical weathering. The least mobile trace elements of the profile are Sc, Cu, Nb, and Ta, but others are more mobile. Thorium, for example, is mobilized during weathering of the Toorongo Granodiorite and displays a twofold increase in the profile, as does the Th/Sc ratio. The ratio, however, varies by more than a hundredfold in major rock types so that Th/Sc (and other ratios) provides valuable information about provenance, although sensitivity is diminished somewhat by the effects of chemical weathering.

Nesbitt, H. Wayne; Markovics, G.

1997-04-01

389

The formation of residual pedogenic clays by limestone weathering  

SciTech Connect

The weathering of carbonate rocks and formation of residual soils differs markedly from processes associated with formation of soils on other rock types. Soils derived from non-carbonate rocks, for example, will invariably produce a weathered product whose volume significantly exceeds that of the original parent rock (because of the formation of less dense, hydrated silicates and oxyhydroxides); the weathering of carbonate rocks, however, produces an infinitely smaller volume of residual weathering products because the soil must originate from the small amount of insoluble residue present in the parent limestone. Further, because limestones are often deposited in a quiet (low energy) shelf environment, or adjacent to land areas where a minimal supply of clastic debris is available, the minerals that are involved in the formation of residual soils are largely authigenic in origin. The Yucatan Peninsula of Mexico is an ideal site to observe these processes and all stages of soil development on limestones are present. Emergence of the region began in the Middle Tertiary and, because surface streams are wholly lacking in the northern peninsula, the soils that are now present do not include any detrital, clastic components. Examination of the insoluble residues of limestones shows that the source materials for the soils consisted of authigenic talc, chlorite, palygorskite, smectite, and mixed layer clays. Subaerial weathering of these limestones initially results in release of the trace amount of clays and formation of poorly crystalline, 10 angstrom halloysite (plus amorphous oxyhydroxides of iron and aluminum); as the profiles thicken and mature, halloysite is slowly transformed to well crystallized kaolinite and goethite, lepidocrocite, and boehmite may also appear. The stage of development of the soils was noted to be closely related with the geomorphic maturity of the region, and the thickest profiles were associated with areas of mature cone karst.

Carr, M.B.; Isphording, W.C.; O'Hearn, S.M.; Kusion, J.E. (Univ. of South Alabama, Mobile, AL (United States). Dept. of Geology-Geography)

1992-01-01

390

Chemical Weathering in the Amur River  

NASA Astrophysics Data System (ADS)

The Amur River is the fourth largest river (~1,855,000 km2) in north Eurasia which flow into the Pacific Ocean. It flows through 4 countries-the Russian Far East, northeast China, east Mongolia and a small territory of North Korea. Climatic and ecological conditions differ significantly from western intercontinental region to eastern coastal area. Southern part of the Amur basin is mostly lowland region with alluvial deposits and various rocks of sedimentary and magmatic origin. In the northern part, there are mountains with siliceous and carbonaceous sedimentary rocks, and permafrost plays an important role in river chemical discharge. We examined dissolved major element and Sr isotopic compositions of 19 summer samples in the middle reach of the Amur to better understand the relationship between chemical weathering, geology, and climate (with the aid of GlS). We found that the 87Sr/86Sr ratios fall a narrow the range of 0.709-0.712 and the TDS (total dissolved solids) is about 80 (40-180) mg/L. Kaolinite is the thermodynamically stable silicate mineral for most samples. We quantified chemical weathering rates using an inverse model: rain accounts for (2-14)% of the total cationic concentration, evaporites (3-19)%, carbonates (43-77)%, and silicates (14-32)%. Net CO2 consumption rate by silicate weathering in the Amur basin is in the range of (10-100) ×103 mol/km2/yr, and the value at the main channel above confluence with the Sungari tributary is ~10 ×103 mol/km2/yr. We tested correlations between the CO2 consumption rates by silicate weathering and various climatic (air temperature, precipitation, and runoff) and geologic (relief, slope, elevation) factors calculated using GIS. Stepwise regression using SPSS on the entire data set yielded best correlation (negative) with elevation (R2 = 0.6823, p = 0.0002).

Moon, S.; Huh, Y.

2006-12-01

391

Federal Plan for Weather Radars.  

National Technical Information Service (NTIS)

The plan for weather radars describes the use of national weather radar resources in providing warnings and forecasts of severe weather for all walks of life within the U.S. Information is given on disaster warnings, general weather forecasting special De...

1973-01-01

392

Social Aspects of Weather Modification  

Microsoft Academic Search

A description of the social context and citizen response to three weather modification projects provides an introduction to the discussion of a variety of social and economic issues related to planned weather modification. Various interest groups have markedly different perspectives on weather modification. Most persons subject to the consequences of weather modification have no opportunity to participate in the associated

J. Eugene Haas

1973-01-01

393

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

NASA Astrophysics Data System (ADS)

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 is important to distinguish among the various types of sedimentary rocks and their diagenetic history to evaluate the spatial distribution of rock weathering and thus lateral inorganic carbon fluxes. Results highlight the role of hotspots (>10 times global average weathering rates) and hyperactive areas (5 to 10 times global average rates). Only 9% of the global exorheic area is responsible for about 50% of CO2- consumption by chemical weathering (or if hotspots and hyperactive areas are considered: 3.4% of exorheic surface area corresponds to 28% of global CO2-consumption). The contribution of endorheic areas to the global CO2-consumption is with 3.7 Mt C a-1 only minor. A significant impact on the global CO2-consumption rate can be expected if identified highly active areas are affected by changes in the overall spatial patterns of the hydrological cycle due to ongoing global climate change. Specifically if comparing the Last Glacial Maximum with present conditions it is probable that also the global carbon cycle has been affected by those changes. It is expected that results will contribute to improve global carbon and global circulation models. In addition, recognizing chemical weathering rates and geochemical composition of certain lithological classes may be of value for studies focusing on biological aspects of the carbon cycles (e.g. studies needing information on the abundance of phosphorus or silica in the soil or aquatic system). Reference: Hartmann, J., Kempe, S, Dürr, H.H., Jansen, N. (2009) Global CO2-consumption by chemical weathering: What is the contribution of highly active weathering regions?. Global and Planetary Change, 69, 185-194. doi:10.1016/j.gloplacha.2009.07.007

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

2010-05-01

394

Effects of pure silica coatings on thermal emission spectra of basaltic rocks: Considerations for Martian surface mineralogy  

Microsoft Academic Search

(1) On Mars, silica derived from chemical weathering could precipitate to coat rocks and particles. We suggest that rock coatings of secondary amorphous silica may account for a widespread Martian surface spectral unit previously modeled as andesite or weathered basalt. In a laboratory study, we investigated the effects of synthetic silica coatings on thermal infrared (TIR) spectroscopic measurements. Secondary amorphous

Michael D. Kraft; Joseph R. Michalski; Thomas G. Sharp

2003-01-01

395

Thermal Inertia of Rocks and Rock Populations  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

396

Classifying Rocks  

NSDL National Science Digital Library

Plants and animals are usually organized by their family tree (origin) and by their physical and genetic characteristics. This activity helps to demonstrate to students that geologists do the same with rocks, which are usually organized by their origin and by their physical and chemical characteristics. To have a better understanding of nature and as one of the initial steps of scientific understanding, it is important for humans to organize nature into groups. This site has a list of materials, background information, a detailed procedure, and a suggestion for assessment.

397

Sedimentary Rocks  

NASA Technical Reports Server (NTRS)

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

2005-01-01

398

Rock Showdown  

NSDL National Science Digital Library

Service learning is a pedagogy that has the potential to connect young adolescents with their community in authentic situations where they can initiate projects that address real needs. The use of the "community" as a context for service and learning has long been explored in science education. There are many examples of service learning initiatives which generally fall under the heading of community-based education . In most cases, students carry out service projects for the community, and along the way may learn some science. By contrast, seventh-grade students from Philippine Science High School created the Rock Showdown as a model of service learning in partnership with the community.

Laroder, Aris; Tippins, Deborah; Morano, Lourdes; Handa, Vicente

2007-03-01

399

All About Rocks  

NSDL National Science Digital Library

We will be learning about different types of rocks today.This project will teach you how to sort rocks based upon color, hardness, texture, layering, and particle size. We will even see a video of new rocks being formed! Visit this link to read an intro about rocks. Intro to Rocks Then visit these three links 1) Metamorphic Rocks 2) Igneous Rocks 3) Sedimentary Rocks Now answer these questions: 1) What types of rocks do you think you would find in your backyard? 2)Compare and contrast 2 of the 3 different types of rocks. 3)What is your favorite ...

Heffernan, Laura

2010-06-21

400

Phosphine from rocks: mechanically driven phosphate reduction?  

PubMed

Natural rock and mineral samples released trace amounts of phosphine during dissolution in mineral acid. An order of magnitude more phosphine (average 1982 ng PH3 kg rock and maximum 6673 ng PH3/kg rock) is released from pulverized rock samples (basalt, gneiss, granite, clay, quartzitic pebbles, or marble). Phosphine was correlated to hardness and mechanical pulverization energy of the rocks. The yield of PH3 ranged from 0 to 0.01% of the total P content of the dissolved rock. Strong circumstantial evidence was gathered for reduction of phosphate in the rock via mechanochemical or "tribochemical" weathering at quartz and calcite/marble inclusions. Artificial reproduction of this mechanism by rubbing quartz rods coated with apatite-phosphate to the point of visible triboluminescence, led to detection of more than 70 000 ng/kg PH3 in the apatite. This reaction pathway may be considered a mechano-chemical analogue of phosphate reduction from lightning or electrical discharges and may contribute to phosphine production via tectonic forces and processing of rocks. PMID:16294866

Glindemann, Dietmar; Edwards, Marc; Morgenstern, Peter

2005-11-01

401

Oceans, Climate and Weather  

NSDL National Science Digital Library

What is the difference between weather and climate? What do the oceans have to do with them? Weather is the day-to-day state of the atmosphere and its short-term (minutes to weeks) variation. Climate is typically described by the regional patterns of seasonal temperature and precipitation over 30 years. The averages of annual temperature, rainfall, cloud cover, and depth of frost penetration are all typical climate-related statistics. The oceans influence the worlds climate by storing solar energy and distributing it around the planet through currents and atmospheric winds.This publication is all about developing your students understandings of earths oceans and the major effect they have on climate. Understanding and interpreting local weather data and understanding the relationship between weather and climate are important first steps to understanding larger-scale global climate changes. Activities that ask students to collect and analyze local weather data as well as analyze global data can be found in the Lessons and Activities section. Analyzing and interpreting data is a major focus of this publication. Numerous data sets can be found in the Sources for Real Data section. The Background Information section and the article Tomorrows Forecast will help reinforce your own content knowledge.

Lightle, Kimberly

2006-01-01

402

Oceans, Climate, and Weather  

NSDL National Science Digital Library

This resource guide from the Middle School Portal 2 project, written specifically for teachers, provides links to exemplary resources including background information, lessons, career information, and related national science education standards. What is the difference between weather and climate? What do the oceans have to do with them? Weather is the day-to-day state of the atmosphere and its short-term (minutes to weeks) variation. Climate is typically described by the regional patterns of seasonal temperature and precipitation over 30 years. The averages of annual temperature, rainfall, cloud cover, and depth of frost penetration are all typical climate-related statistics. The oceans influence the worlds climate by storing solar energy and distributing it around the planet through currents and atmospheric winds.This publication is all about developing your students understandings of earths oceans and the major effect they have on climate. Understanding and interpreting local weather data and understanding the relationship between weather and climate are important first steps to understanding larger-scale global climate changes. Activities that ask students to collect and analyze local weather data as well as analyze global data can be found in the Lessons and Activities section. Analyzing and interpreting data is a major focus of this publication. Numerous data sets can be found in the Sources for Real Data section. The Background Information section and the article Tomorrows Forecast will help reinforce your own content knowledge.

Lightle, Kimberly

2006-10-01

403

Rock Driller  

NASA Technical Reports Server (NTRS)

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.

Peterson, Thomas M.

2001-01-01

404

Tectonic Control of Chemical Weathering and CO2 Drawdown in a Steady State Landscape  

NASA Astrophysics Data System (ADS)

We present a combined steady-state chemical weathering model and field-based study that examines the effects of soil depth and uplift rate on chemical weathering rates across a climate/tectonic uplift gradient. This work demonstrates the importance of rock uplift on chemical weathering relative to the effects of precipitation and temperature and shows that climatically focused erosion acts as a driver of silicate weathering, providing a direct link between climate, tectonics, and CO2 drawdown. Our model is applied to the Skykomish river basin in the central Washington Cascades. This drainage basin was selected because previous work (Reiners et al. 2003) has shown that long-term erosion rates in the central Cascades are strongly coupled with modern mean annual precipitation patterns suggesting long-term climatically focused erosion in a steady-state topography. Our analysis of cation fluxes from thirteen catchments within this basin show that silicate weathering is strongly dependent on the rate of supply of easily weathered material and the depth of the zone of weathering. As such, the central Washington Cascades are primarily supply-limited, where weathering-derived Si fluxes are directly related to the rate of rock advection into the zone of active weathering. These data show that chemical weathering is strongly linked to areas of high exhumation, such that CO2 drawdown is approximately 1.5 times higher in areas of rapid exhumation when compared to areas of low exhumation.

Hren, M. T.; Hilley, G.; Chamberlain, C.

2005-12-01

405

Delicious Differential Weathering  

NSDL National Science Digital Library

Students are asked to place a Baby Ruth candy bar in their mouths but are asked not to bite it. Once they have sucked off all the chocolate and caramel the students are given permission to bite the peanuts. After lecturing on the differences between chemical and physical weathering students are asked to list the order of ingredients they tasted. Each group is given a sample of granite. Students are asked to list three visible minerals in the granite. Relate the minerals of the granite (hornblende, feldspar, and quartz) to the ingredients of the candy bar. Explain Bowen's reaction series and how different minerals will weather first and how climate will affect weathering rates.

Gorte, Mary

406

Extreme Weather Sourcebook  

NSDL National Science Digital Library

This report presents a summary of damage caused by hurricanes, floods, tornadoes, lightning, hail, thunderstorms, and windstorms in the United States and its territories. Information was collected from as far back as 1900 (for hurricanes) and as recently as 1999 (for most categories). For each weather category, there is statistical information on monetary damages (in millions of dollars), sorted by rank and by alphabetic listing. There is also a summary table for composite damage from tornadoes, hurricanes, and floods; tables and graphs for damage and casualties caused by lightning; and summary information for other types of extreme weather (hail, thunderstorms, winter storms). Links are provided to information on data sources and methodology and on the societal impacts of weather.

407

Planetary Space Weather  

NASA Astrophysics Data System (ADS)

Invited Talk - Space weather at other planets While discussion of space weather effects has so far largely been confined to the near-Earth environment, there are significant present and future applications to the locations beyond, and to other planets. Most obviously, perhaps, are the radiation hazards experienced by astronauts on the way to, and on the surface of, the Moon and Mars. Indeed, the environment experienced by planetary spacecraft in transit and at their destinations is of course critical to their design and successful operation. The case of forthcoming missions to Jupiter and Europa is an exreme example. Moreover, such craft can provide information which in turn increases our understanding of geospace. Indeed, space weather may be a significant factor in the habitability of other solar system and extrasolar planets, and the ability of life to travel between them.

Grande, M.

2012-04-01

408

Large-Scale Weather  

NSDL National Science Digital Library

In the previous chapter, we dealt with how the properties of air and water affected small-scale weather such as the formation of clouds, the formation of fog, and how comfortable you feel at different times of the year. In this chapter, we're going to go global, talking about major interactions between the Sun and Earth, the resulting effects on large air masses, and how these major interactions help us figure out what the weather's going to be tomorrow. As discussed earlier in the book, when science concepts are applied to the real world, things don't always work out exactly as expected. However, it is possible to get an overall picture of what's happening in large-scale weather.

Robertson, William C.

2005-01-01

409

Linking Weather and Climate  

NASA Astrophysics Data System (ADS)

This presentation provides an overview major phenomena and mechanisms linking weather and climate variations, with a focus on a subset of major, recurrent phenomena that impact extratropical wintertime weather and climate variations over the Pacific-North American region. While progress in advancing understanding has been impressive, research has also illuminated areas where significant future gains are possible. Emerging thrusts in international and national research priorities suggest that over time artificial distinctions will be removed between "weather" and "climate", as we begin to achieve a more unified understanding of phenomena and processes that bridge time scales. We discuss these research thrusts, which are likely to serve as increasingly vital components of an overall research strategy in earth system science.

Dole, R.

2006-05-01

410

Weather Scope: An Investigative Study of Weather and Climate  

NSDL National Science Digital Library

During the course of this project, students will learn how to build instruments to measure weather, access online weather observations, collect weather data for an extended period, analyze weather data to reveal trends, and make predictions. They will develop a basic understanding of how weather can be described in measurable quantities such as temperature, wind and precipitation. The module contains five lessons relating to weather, five relating to climate, and three enrichment activities. Project information, a teacher guide, reference materials, and an "ask an expert" feature are also provided.

411

Wisconsin Weather Stories  

NSDL National Science Digital Library

University of Wisconsin meteorologists and folklorists along with Wisconsin teachers created this website to offer classroom materials "that integrate earth science, social studies, language arts, and math." Students can learn about severe weather and the importance of forecasting by listening to and reading people's accounts. Each lesson contains benchmarks and standards for grades four, eight, and twelve; as well as many fun activities. The website features a concise glossary and many links where teachers can discover more resources. Visitors who remember the weather discussed, such as the Ice Bowl of 1967, can find out how to submit their accounts to the website.

412

Reading Weather Maps  

NSDL National Science Digital Library

From the University of Illinois at Urbana-Champaign's Department of Atmospheric Sciences comes the Reading Weather Maps Web site. Visitors learn how to convert their local time to the standard used by all meteorologists; to tell the difference between Kelvin, Celsius, and Fahrenheit temperatures; and how to read maps with weather data collected on and above the Earth's surface. For example, wind bards, which are flag-like symbols that indicate wind direction and wind speed, always point in the direction the wind is blowing "from." Other interesting facts, descriptions, and illustrations are available on the site.

1969-12-31

413

Weather and The Seasons  

NSDL National Science Digital Library

This project will allow students to see the different weather conditions that are apart of the different seasons. It will also help students to identify the characterisitics that go along with each of the different seasons, For example, what weather conditions are present in each season and how we dress for each season. With a partner watch the video: Observing Clouds On piece of paper write your answers to the following questions: 1). What types of changes in the clouds did you observe? 2). What do you think caused the changes in the clouds? (Ex: teperature, morning to night, etc) Next, with your partner, please watch the second video: Observing Precipitation On ...

Maxwell, Ms.

2012-02-07

414

Weather Station Model  

NSDL National Science Digital Library

This lesson instructs students on how to read station models, the symbols used on weather maps to show data (temperature, wind speed and direction, barometeric pressure, etc.) for a given reporting station. It includes a diagram of a station model, an explanation of the data conveyed by the numbers and symbols, and a table of definitions for the graphic symbols used with models. There is also a set of interactive station models students can use for practice at interpretation, and an interactive exercise in which students use real-time weather data to interpret models.

415

Factors affecting the durability of selected weak and clay-bearing rocks from Turkey, with particular emphasis on the influence of the number of drying and wetting cycles  

Microsoft Academic Search

Weathering can induce a rapid change of rock material from initial rock-like properties to soil-like properties. The resistance of a rock to short-term weathering is described through a durability parameter called the slake durability index. As durability is an important engineering parameter, particularly for weak and clay-bearing rocks, it was assessed by a number of tests. The main purpose of

Candan Gökceo?lu; Resat Ulusay; Harun Sönmez

2000-01-01

416

Effects of climate on chemical weathering in watersheds  

USGS Publications Warehouse

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

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

1995-01-01

417

Rocks and Minerals  

NSDL National Science Digital Library

This web page offers a simple illustrated guide to the three rock types- igneous, sedimentary, and metamorphic; and the most common rock-forming mineral groups: quartz, plagioclase feldspars, potassium feldspars, micas, amphiboles, olivine, and calcite. The rock types include extrusive and intrusive igneous rocks, clastic, biologic, and chemical sedimentary rocks, and both foliated and non-foliated metamorphic rocks. A section is included on naming igneous rocks. The igneous rocks tuff and basalt are also discussed, as is sediment. Users are directed to related resources and may print out a simplified rock classification chart.

418

External Resource: Rock Cycle Animation  

NSDL National Science Digital Library

This cutaway view of Earth shows where some common rock-forming processes occur. Embedded animations will illustrate the path of a rock moving through the rock cycle. Topics include: rock cycle, magma chamber, magma, igneous rock, sedimentary rock, erosio

1900-01-01

419

Weather Depot 1.21  

NSDL National Science Digital Library

As a quote commonly misattributed to Mark Twain goes, "Everyone talks about the weather, but no one does a thing about it." This little program from the folks at Weather Depot won't allow users to modify weather conditions, but it will let users customize their own weather planner (with hourly and daily updates), view regional radar, and view a map of current temperatures around the United States. Additionally, users may look up current road conditions, and view weather Web cams. Weather Depot 1.21 is compatible with all systems running Windows 98 and higher.

420

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

NASA Astrophysics Data System (ADS)

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 be a function not only of rock properties (such as the degree of weathering, mineral composition, and grain sizes) but also of the environmental conditions and other factors. Nevertheless, the SGE deduced from the RAT engineering data, and linked with data from other instruments in the payload, represent the most comprehensive database yet created of the physical properties of Martian rocks and are therefore of great value to our understanding of the geologic history of Mars and future instrument design for forthcoming Mars missions.

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

2005-12-01

421

Space Weather Forecasting at NASA GSFC Space Weather Research Center  

NASA Astrophysics Data System (ADS)

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.

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

422

Winds, Weather, and Deserts  

NSDL National Science Digital Library

This site contains 17 questions on the topic of wind and weathering, which covers the Coriolis Effect and wind characteristics. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit an answer and are provided immediate verification.

Heaton, Timothy

423

Blogging About the Weather  

NSDL National Science Digital Library

Since the majority of the content standards related to weather focus on forecasting, elementary students often spend a lot of time studying cloud types, fronts, storms, and using a barometer to read air pressure. Although this allows students to "do" scie

Evans, Kyle; Frazier, Wendy

2010-04-01

424

Controlled Temperature Natural Weathering  

Microsoft Academic Search

Attempting to quantify and predict the exterior service life performance of a coating is an essential and frequently undertaken activity in the technical sections of the paint and surface coating industry. Such work, usually termed weathering or durability studies, is carried out in an attempt to underpin new product development, or to provide a measure of assurance of the in-use

Anthony Buxton; Jon A. Graystone; Richard Holman; Francesco Macchi

425

Space Weather Center  

NSDL National Science Digital Library

This site offers information and images about plasmas, solar flares, and magnetic storms. Users will find out about the "solar wind," and its influence on a stream of particles from the sun which leads to interaction with Earth's magnetic field and consequently the change in space weather. Interactive illustrations and games are also included.

2006-07-18

426

Weather and Health  

NSDL National Science Digital Library

Funded by the National Environmental Education Foundation (NEEF), this course will help meteorologists and others broaden their understanding of the impacts of weather and climate on public health, including the impacts of heat waves and cold temperatures, winter storms and thunderstorms, flooding, drought, poor air quality, tornadoes, hurricanes, wildfire, ultraviolet radiation, and other phenomena.

2008-01-01

427

Dress for the Weather  

ERIC Educational Resources Information Center

"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…

Glen, Nicole J.; Smetana, Lara K.

2010-01-01

428

Accessing Space Weather Information  

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

429

Introduction to Space Weather  

Microsoft Academic Search

Adverse space weather is one of the principal threats to modern human technology. Solar coronal mass ejections, large solar flares, and high-speed solar wind streams often lead to sequences of damaging disturbances within the Earths magnetosphere, in the atmosphere, and even on the Earths surface. Powerful and long-lasting geomagnetic storms can develop following solar disturbances and enhancements of the highly

Daniel N. Baker

2004-01-01

430

Introduction to Space Weather  

Microsoft Academic Search

Adverse space weather is one of the principal threats to modern human technology. Solar coronal mass ejections, large solar flares, and high-speed solar wind streams often lead to sequences of damaging disturbances within the Earths magnetosphere, in the atmosphere, and even on the Earths surface. Powerful and long-lasting geomagnetic storms can develop following solar disturbances and enhancements of the highly

Daniel N. Baker

431

Introduction to Space Weather  

Microsoft Academic Search

Adverse space weather is one of the principal threats to modern human technology. Solar coronal mass ejections, large solar flares, and high-speed solar wind streams often lead to sequences of damaging disturbances within the Earth's magnetosphere, in the atmosphere, and even on the Earth's surface. Powerful and long-lasting geomagnetic storms can develop following solar disturbances and enhancements of the highly

Daniel N. Baker

2005-01-01

432

Weathering and mass wasting  

NSDL National Science Digital Library

This class exercise is an opportunity for students to apply textbook information about weathering and mass wasting to local and nationally-recognized surface features, such as Stone Mountain (GA), Half Dome (CA), and others. It also serves as an introduction to the use of Google Earth as an analytical tool for calculating distances, slopes, and evaluating landforms. Designed for a geomorphology course

Clayton, Jordan

433

Weather and Flight Testing  

NASA Technical Reports Server (NTRS)

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.

Wiley, Scott

2007-01-01

434

Sunspots and Space Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and is an online investigation for students in how sunspots impact space weather between the Sun and Earth. Students research solar maximum and minimum as well as recent sunspot numbers to determine a connection between the numbers and solar activity. This page is accompanied by a page of websites for further resources.

435

Worldwide Marine Weather Broadcasts.  

ERIC Educational Resources Information Center

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…

Department of the Navy, Washington, DC.

436

Weatherization Works: An interim report of the National Weatherization Evaluation  

SciTech Connect

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.

Brown, M.A.; Berry, L.G. [Oak Ridge National Lab., TN (United States); Kinney, L.F. [Synertech Systems Corp., Syracuse, NY (United States)

1993-11-01

437

Image Archive: Sedimentary Rocks  

NSDL National Science Digital Library

This archive provides descriptions and photos of the several types of sedimentary rocks. A definition of sedimentary rocks and overview of the basic classification is provided. Links to additional examples of chemical and clastic rocks are also included.

Celestian, Stan

438

Adhesion in Rocks.  

National Technical Information Service (NTIS)

The objective was to ascertain the magnitude of forces responsible for coherency of rock by quantifying the strength of the attractive forces operating between minerals in rock. These forces oppose stresses set up in various rock gragmentation processes, ...

G. A. Savanick D. I. Johnson

1973-01-01

439

Space weathering of Itokawa, a small rubble pile asteroid  

NASA Astrophysics Data System (ADS)

Itokawa's surface show darkening and reddening by space weathering, although its surface is covered with rocks and pebbles and deficient in fine regolith. Experimental results suggest rocky meteorite fragments can be weathered. The opposition effect in rocky terrain of Itokawa suggested that the surface would be covered by particulate materials or porous enough to scatter light. Itokawa-derived fine grains (some of which have nanophase iron) in Hayabusa sample capsule clearly indicate the presence of fine particles on the surface of Itokawa and their effect on the optical property of the asteroid.

Sasaki, S.; Hiroi, T.

2011-10-01

440

An AEM-TEM study of weathering and diagenesis, Abert Lake, Oregon. (1) Weathering reactions in the volcanics  

SciTech Connect

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 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. 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 transported to the lake and the solution will be described in part.

Banfield, J.F.; Veblen, D.R. (Johns Hopkins Univ., Baltimore, MD (United States)); Jones, B.F. (Geological Survey, Reston, VA (United States))

1991-10-01

441

Weather Forecasting Expert System Study.  

National Technical Information Service (NTIS)

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 a...

1985-01-01

442

External Resource: Erosion and Weathering  

NSDL National Science Digital Library

This is a Teachers' Domain photo essay with images that depict surface features on Earth that result from weathering and erosion, as well as measures designed to mitigate their unwanted effects. Topics: weathering, erosion, sediments, dunes, deltas, glaci

1900-01-01

443

All-Weather Home Building.  

National Technical Information Service (NTIS)

To determine the experiences of contractors in building in a variety of weather conditions, the following tasks are reported and discussed: (1) a summary of literature review and annotated bibliography for all - weather home building, (2) a questionnaire ...

1975-01-01

444

Magnetic study of an Antarctic weathering profile on basalt: Implications for recent weathering on Mars  

NASA Astrophysics Data System (ADS)

In order to better interpret the Martian surface weathering-related mineralogy, we focused on a relevant analogue of the Martian subsurface in terms of lithology and paleoclimate: the Jurassic-aged Ferrar dolerite (Priestley Glacier, Transantarctic Mountains), weathered in cold and dry climate. Together with chemical and mineralogical studies, rock magnetic properties were investigated and completed with Mössbauer measurements. Weathering of the decimetric block is evidenced by chemical profiles showing an increase in Fe content (from 10.5 in the core to 13 wt.% in the surface) and a decrease in Si (from 57 to 53 wt.%, respectively). According to mineralogical, thermomagnetic and hysteresis properties, the main opaque mineral is inherited titanomaghemite, with a concentration about 1%. Enhancement in low field magnetic susceptibility (from 4 · 10 - 6 to 10 · 10 - 6 m 3/kg, respectively) and saturation magnetization (from 0.44 to 0.96 Am 2/kg, respectively) indicates the neoformation of metastable maghemite. Neoformed red ferric (oxy)hydroxides are abundant in the surface. High field susceptibility normalized to iron concentration and Mössbauer spectra indicate a replacement of Fe 2+ from primary silicates (pyroxene) by poorly crystalline antiferromagnetic Fe 3+ (oxy)hydroxides. Thus, highly magnetic titanomaghemite and maghemite coexist with nanosized ferric (oxy)hydroxides and primary silicates, in accordance with Martian in situ observations. Therefore, this study supports the formation of the Martian regolith as resulting from a slow weathering process in near present day conditions.

Chevrier, V.; Mathé, P.-E.; Rochette, P.; Gunnlaugsson, H. P.

2006-04-01

445

Real-Time Weather Data  

NSDL National Science Digital Library

This website provides real-time and forecast weather maps and data for the United States. The Satellite section contains satellite weather images from the GOES 8 and GOES 10 satellites, the Radar section contains radar weather images from NEXRAD radars, the Surface Data section contains plots of various weather conditions (temperatures, winds, pressure, precipitation), and the Upper Air section plots winds and temperatures across the United States.

446

Make Your Own Weather Station  

NSDL National Science Digital Library

This three-part activity shows learners how to build three meteorology tools: a wind vane, a rain gauge, and a barometer. Then, they can use their tools to build their own weather station to record data about the weather, study the data to detect patterns, and use the patterns to predict the