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1

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

2

Sedimentary Rocks and Weathering  

NSDL National Science Digital Library

This site contains 42 questions on the topic of sedimentary rocks and weathering including clast sizes, depositional environments, and products of weathering. This is part of the Principles of Earth Science course at the University of South Dakota. Users select an answer and are provided immediate feedback.

Timothy Heaton

3

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

4

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

5

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

6

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

7

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

8

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

9

Weathering indices and their applicability for crystalline rocks  

Microsoft Academic Search

.   In the recent past, several weathering indices have been proposed to characterize the extent of weathering and weatherability\\u000a depending upon the nature and requirement of the study. The weathering index provides a quantitative measure of the extent\\u000a of weathering of rock; hence it can provide input to the prediction models to assess the strength and deformational properties\\u000a of rocks

Anand S. Gupta; Seshagiri K. Rao

2001-01-01

10

Building Stone and Its Use in Rock Weathering Studies.  

ERIC Educational Resources Information Center

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

Dragovich, Deirdre

1979-01-01

11

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

12

The use of cation packing index for characterizing the weathering degree of granitic rocks  

Microsoft Academic Search

The weathering state and weatherability of rocks are highly important for engineering geology projects and the use of rocks as building stones. The weathering state of rocks can be described by various chemical and petrographical weathering indices. To determine weathering state of a rock, considerable amount of chemical analyses is required. Weatherability of rocks depends on not only their mineral

S. Ceryan; K. Zorlu; C. Gokceoglu; A. Temel

2008-01-01

13

Draft Genome Sequence of Rhizobium sp. H41, a Rock-Weathering Bacterium from a Weathered Rock Surface.  

PubMed

Rhizobium sp. H41 isolated from weathered tuff can weather tuff and release Fe, Si, and Al from the rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain H41, which may facilitate a better understanding of the molecular mechanism involved in rock weathering by the bacterium. PMID:25377707

Xi, Jun; Sheng, Xiafang; He, Linyan

2014-01-01

14

WATER WEATHERING IN ROCKS DISCONTINUITIES Sandra Dochez*1,2  

E-print Network

WATER WEATHERING IN ROCKS DISCONTINUITIES Sandra Dochez*1,2 , Farid Laouafa1 , Christian Franck1.bost@ifsttar.fr Abstract: The behavior of rock discontinuities at different spatial scales remains a major challenge for scientists who want to understand the rock alteration, both in the triggering of rock- fall

Paris-Sud XI, Université de

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

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.

Pamela Gore

1995-08-29

17

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

18

Confined groundwater zone and slope instability in weathered igneous rocks in Hong Kong  

E-print Network

Confined groundwater zone and slope instability in weathered igneous rocks in Hong Kong Jiu J conductivity (K) of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered igneous rocks, if significantly kaolinized, may have low permeability and behave as a confining zone

Jiao, Jiu Jimmy

19

Weathering and Erosion: Simulating Rock Attack in the Lab  

NSDL National Science Digital Library

These activities examine the ways in which water can weather rocks. Simulations of erosion by running water, solution, freeze?thaw and by wind are investigated. Several class laboratory and demonstration activities simulate some of the processes occurring in weathering and erosion. They include a look at the effect of pouring water onto brown sugar to simulate the effect of water on soluble rock, observing the residue left after water samples have evaporated to show that water can dissolve minerals, showing that water expands on freezing by placing a sealed jar of water in the freezer overnight, and inspection of the effect of freezing on a water-soaked sample of porous rock. In addition, an activity simulates the effect of water impact on rocks by pouring water on sand and another uses a hair dryer to simulate wind erosion by sandblasting copper sulfate crystals.

20

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

21

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

22

Association of trace elements with iron oxides during rock weathering  

SciTech Connect

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

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

1980-01-01

23

Rock Rinds at Meridiani and Surface Weathering Phenomena  

NASA Astrophysics Data System (ADS)

The Rock Abrasion Tool (RAT) on the Mars rover Opportunity can brush away surface dust and grind away outcrop surface, exposing presumably less altered rock at depths of several mm. Alpha particle X-ray spectrometer (APXS) and Moessbauer spectrometer (MB) analyses of pre- and post-RAT targets, thus, provide information on the chemical nature of weathering of Meridiani outcrop rocks. To date, Opportunity has analyzed some 25 undisturbed rock surfaces, brushed and then analyzed 7 more, and ground 23 targets for IDD analysis. Panoramic camera images show that outcrop surfaces are typically either buff or purple (as viewed in bands centered at 673, 535, and 432 nm, Farrand et al., JGR, in press). Relatively flat surfaces that are approximately parallel to the ground are typically buff, whereas those that slope steeply tend to be purple. Surfaces of rock interiors ground by the RAT are also commonly purple. Spectrally, these color differences correspond to more oxidized (buff) and less oxidized (purple), and appear to relate to the degree of eolian abrasion. Flat-lying surfaces are not eroded as quickly, thus surfaces chemically weathered by exposure to tenuous atmospheric vapor may be preserved. These observations are consistent with in-situ analyses of rock surfaces and interiors. Compared to interiors, rock surfaces have about 1/3 less S, and in general, surface compositions lie between those of rock interiors and average surface soil. In detail, they differ from soil-rock mixtures as follows: surfaces are relatively depleted in Mg, Fe, Mn, Ti, and Cr, and they are enriched in Al, Na, K, P, Cl, and Si. From MB analyses, surfaces are richer (compared to soil-rock mixtures) in oxidized Fe phases and poorer in magnetite, olivine, and pyroxene. Morphologically, numerous flat-lying rocks and outcrop surfaces that are at or near the ground surface have a rind of erosionally resistant material. Such rinds are also chemically distinct from outcrop interiors. A rind/subjacent rock pair analyzed in detail was "Lemon Rind" and "Strawberry," ca. sols 555-560. The rind is depleted in S (balanced mainly by increased Si and Al) and, compared to a soil-rock mixture, it is depleted in Mg, Ti, Cr, Mn, and slightly in Fe, and it is enriched in Na, Cl, K, and P. Differences between rock surfaces and interiors, and between hardened weathering rinds and rock interiors, are consistent with loss of Mg-sulfate, oxidation of mafic minerals, enrichment of siliciclastic material, e.g., feldspar, and enrichment in chloride. These changes are consistent with slow rates of chemical weathering via interaction with small amounts of atmospheric water vapor or condensation. Erosionally resistant rinds may be related to preservation of aqueous condensate by a thin cover of soil on flat, near-surface rocks.

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

2006-12-01

24

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

25

Controls on the Development of Rock Weathering Pits  

NSDL National Science Digital Library

Weathering pits are well known from granite terrains and they also form in metaquartzite along the Blue Ridge Parkway in North Carolina. We will drive to Flat Rock Trail, along the Blue Ridge Parkway near Linville, NC. After a short hike up the trail we will observe the weathering pits exposed on the bedrock surface overlooking the Linville Valley. Each group of students will write down 3 hypotheses for how and why they form. Consider what factors control the size and shape of the pits. Collect data that can be used to test the hypotheses including orientation, size, and shape. Plot the data collected in the field. Present data on graphs and charts. Do trends in the data support one hypothesis over another? Designed for a geomorphology course

Ellen Cowan

26

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

E-print Network

Cracks in desert pavement rocks: Further insights into mechanical weathering by directional Fractures The formation of cracks is a fundamental first step in the physical weathering of rocks in desert not readily attributable to rock anisotropies or shape) in boulders or cobbles form due to tensile stresses

Ahmad, Sajjad

27

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.

28

Analysis on weathering characteristics of volcanic rocks in Dokdo, Korea based on accelerated weatehring experiments  

Microsoft Academic Search

Dokdo consists of small volcanic islands located in the southern part of the East Sea. Accelerated weathering tests was performed to examine the physico-mechanical characteristics of volcanic rocks in Dokdo. Rock core specimens of trachyandesite, andesitic dyke and ash tuff were prepared, and double soxhlet extractors(DSE) and peristatic pumps were used for accelerating the weathering processes. The DSE was designed

Ik Woo; Won-Kyong Song; Bok-Chul Kim; Jinseok Kang

2010-01-01

29

Generalized soil Thaumarchaeota community in weathering rock and Saprolite.  

PubMed

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

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

2015-02-01

30

Antarctic glaciers and rock weathering: Exploring chemical and mineralogy processes within the blue ice fields  

E-print Network

Antarctic glaciers and rock weathering: Exploring chemical and mineralogy processes within the blue of Antarctic ordinary chondrites that have undergone different degrees of weathering. Questions to be asked the Antarctic ice, and meltwater pools, so that weathering rates can be determined. The student will work

Guo, Zaoyang

31

Plant-induced weathering of a basaltic rock: experimental evidence  

NASA Astrophysics Data System (ADS)

The active role of higher plants in the weathering of silicate minerals and rocks is still a question for debate. The present work aimed at providing experimental evidence of the important role of a range of crop plants in such processes. In order to quantitatively assess the possible effect of these diverse plant species on the weathering of a basaltic rock, two laboratory experiments were carried out at room temperature. These compared the amounts of elements released from basalt when leached with a dilute salt solution in the presence or absence of crop plants grown for up to 36 days. For Si, Ca, Mg, and Na, plants resulted in an increase in the release rate by a factor ranging from 1 to 5 in most cases. Ca and Na seemed to be preferentially released relative to other elements, suggesting that plagioclase dissolved faster than the other constituents of the studied basalt. Negligible amounts of Fe were released in the absence of plants as a consequence of the neutral pH and atmospheric pO 2 that were maintained in the leaching solution. However, the amounts of Fe released from basalt in the presence of plants were up to 100- to 500-fold larger than in the absence of plants, for banana and maize. The kinetics of dissolution of basalt in the absence of plants showed a constantly decreasing release rate over the whole duration of the experiment (36 days). No steady state value was reached both in the absence and presence of banana plants. However, in the latter case, the rates remained at a high initial level over a longer period of time (up to 15 days) before starting to decrease. For Fe, the maximum rate of release was reached beyond 4 days and this rate remained high up to 22 days of growth of banana. The possible mechanisms responsible for this enhanced release of elements from basalt in the presence of plants are discussed. Although these mechanisms need to be elucidated, the present results clearly show that higher plants can considerably affect the kinetics of dissolution of basalt rock. Therefore, they need to be taken into account when assessing the biogeochemical cycles of elements that are major nutrients for plants, such as Ca, Mg, and K, but also micronutrients such as Fe and 'nonessential' elements such as Si and Na.

Hinsinger, Philippe; Fernandes Barros, Omar Neto; Benedetti, Marc F.; Noack, Yves; Callot, Gabriel

2001-01-01

32

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

E-print Network

Storage and release of fossil organic carbon related to weathering of sedimentary rocks Yoann.e., the ancient organic matter stored in sedimentary rocks) is widely observed in modern environments meter of sedimentary rocks and a first estimation of annual FOC delivery to the modern environment

Paris-Sud XI, Université de

33

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

PubMed

A novel mineral-weathering bacterium was isolated from weathered rock (potassic trachyte) surfaces collected from Nanjing (Jiangsu, PR China). Cells of strain JN246(T) were Gram-stain-negative, rod-shaped and non-motile. Strain JN246(T) was aerobic, catalase- and oxidase-positive, and grew optimally at 28 °C and pH 7.0. On the basis of 16S rRNA gene sequence analysis, strain JN246(T) belonged to the genus Chitinophaga and the closest phylogenetic relatives were Chitinophaga eiseniae YC6729(T) (98.5% 16S rRNA gene sequence similarity), Chitinophaga terrae KP01(T) (96.8%), and Chitinophaga jiangningensis JN53(T) (96.3?%). The major respiratory quinone was MK-7 and the major polyamine was homospermidine. The major fatty acids were iso-C15:0, C16:1?5c, C16:0 and iso-C17:0 3-OH. The polar lipid profile of strain JN246(T) consisted of phosphatidylethanolamine, unknown aminolipids and unknown lipids. The genomic DNA G+C content of strain JN246(T) was 48.8 mol%. Based on the low level of DNA-DNA relatedness of strain JN246(T) (ranging from 22.6% to 42.4%) to the type strains of other species of the genus Chitinophaga and unique phenotypic characteristics, strain JN246(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga qingshengii sp. nov. is proposed. The type strain is JN246(T) (?=?CCTCC AB 2014201(T)?=?JCM 30026(T)). PMID:25342110

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

2015-01-01

34

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

35

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

PubMed

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

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

2012-09-01

36

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

PubMed

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

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

2004-09-01

37

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

PubMed

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

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

1981-01-01

38

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

39

Porosity and surface area evolution during weathering of two igneous rocks  

NASA Astrophysics Data System (ADS)

During weathering, rocks release nutrients and store water vital for growth of microbial and plant life. Thus, the growth of porosity as weathering advances into bedrock is a life-sustaining process for terrestrial ecosystems. Here, we use small-angle and ultra small-angle neutron scattering to show how porosity develops during initial weathering under tropical conditions of two igneous rock compositions, basaltic andesite and quartz diorite. The quartz diorite weathers spheroidally while the basaltic andesite does not. The weathering advance rates of the two systems also differ, perhaps due to this difference in mechanism, from 0.24 to 100 mm kyr-1, respectively. The scattering data document how surfaces inside the feldspar-dominated rocks change as weathering advances into the protolith. In the unaltered rocks, neutrons scatter from two types of features whose dimensions vary from 6 nm to 40 ?m: pores and bumps on pore-grain surfaces. These features result in scattering data for both unaltered rocks that document multi-fractal behavior: scattering is best described by a mass fractal dimension (Dm) and a surface fractal dimension (Ds) for features of length scales greater than and less than ˜1 ?m, respectively. In the basaltic andesite, Dm is approximately 2.9 and Ds is approximately 2.7. The mechanism of solute transport during weathering of this rock is diffusion. Porosity and surface area increase from ˜1.5% to 8.5% and 3 to 23 m2 g-1 respectively in a relatively consistent trend across the mm-thick plagioclase reaction front. Across this front, both fractal dimensions decrease, consistent with development of a more monodisperse pore network with smoother pore surfaces. Both changes are consistent largely with increasing connectivity of pores without significant surface roughening, as expected for transport-limited weathering. In contrast, porosity and surface area increase from 1.3% to 9.5% and 1.5 to 13 m2 g-1 respectively across a many cm-thick reaction front in the spheroidally weathering quartz diorite. In that rock, Dm is approximately 2.8 and Ds is approximately 2.5 prior to weathering. These two fractals transform during weathering to multiple surface fractals as micro-cracking reduces the size of diffusion-limited subzones of the matrix. Across the reaction front of plagioclase in the quartz diorite, the specific surface area and porosity change very little until the point where the rock disaggregates into saprolite. The different patterns in porosity development of the two rocks are attributed to advective infiltration plus diffusion in the rock that spheroidally fractures versus diffusion-only in the rock that does not. Fracturing apparently diminishes the size of the diffusion-limited parts of the spheroidally weathering rock system to promote infiltration of meteoric fluids, therefore explaining the faster weathering advance rate into that rock.

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

2013-05-01

40

Porosity and surface area evolution during weathering of two igneous rocks  

SciTech Connect

During weathering, rocks release nutrients and storewater vital for growth ofmicrobial and plant life. Thus, the growth of porosity as weathering advances into bedrock is a life-sustaining process for terrestrial ecosystems. Here, we use small-angle and ultra small-angle neutron scattering to show how porosity develops during initial weathering under tropical conditions of two igneous rock compositions, basaltic andesite and quartz diorite. The quartz diorite weathers spheroidally while the basaltic andesite does not. The weathering advance rates of the two systems also differ, perhaps due to this difference in mechanism, from 0.24 to 100 mm kyr1, respectively. The scattering data document how surfaces inside the feldspar-dominated rocks change as weathering advances into the protolith. In the unaltered rocks, neutrons scatter fromtwo types of featureswhose dimensions vary from6 nmto 40 lm: pores and bumps on pore grain surfaces. These features result in scattering data for both unaltered rocks that document multi-fractal behavior: scattering is best described by amass fractal dimension (Dm) and a surface fractal dimension (Ds) for features of length scales greater than and less than 1 lm, respectively. In the basaltic andesite, Dm is approximately 2.9 and Ds is approximately 2.7. The mechanism of solute transport during weathering of this rock is diffusion. Porosity and surface area increase from 1.5%to 8.5%and 3 to 23 m2 g1 respectively in a relatively consistent trend across themm-thick plagioclase reaction front. Across this front, both fractal dimensions decrease, consistentwith development of amoremonodisperse pore networkwith smoother pore surfaces. Both changes are consistent largely with increasing connectivity of pores without significant surface roughening, as expected for transport-limited weathering. In contrast, porosity and surface area increase from 1.3% to 9.5% and 1.5 to 13 m2 g1 respectively across a many cm-thick reaction front in the spheroidally weathering quartz diorite. In that rock, Dm is approximately 2.8 andDs is approximately 2.5 prior to weathering. These two fractals transform during weathering to multiple surface fractals as micro-cracking reduces the size of diffusion-limited subzones of thematrix.Across the reaction front of plagioclase in the quartz diorite, the specific surface area and porosity change very little until the pointwhere the rock disaggregates into saprolite. The different patterns in porosity development of the two rocks are attributed to advective infiltration plus diffusion in the rock that spheroidally fractures versus diffusion-only in the rock that does not. Fracturing apparently diminishes the size of the diffusion-limited parts of the spheroidally weathering rock system to promote infiltration of meteoric fluids, thereforeexplaining the faster weathering advance rate into that rock.

Navarre-Sitchler, Alexis [Colorado School of Mines, Golden; Cole, David [Ohio State University; Rother, Gernot [ORNL; Jin, Lixin [University of Texas, El Paso; Buss, Heather [University of Bristol, UK; Brantley, S. L. [Pennsylvania State University, University Park, PA

2013-01-01

41

[Enrichment and release of uranium during weathering of sedimentary rocks in Wujiang catchments].  

PubMed

Thirteen weathering profiles of typical rocks such as limestone, dolomitic limestone, dolomite, sillcalite, black shale and purple sandrock from Wujiang catchments were selected for discussing enrichment and release behavior of uranium (U) during rock weathering, and studying its impact on riverine U distribution in the catchments during weathering of these rocks with methods of correlation analysis and mass balance calculation. The purpose of this study is to improve our understanding on biogechemical cycling of U and set a basis for catchment protection against U pollution. The results show that the enrichment extent of U in soils from the Wujiang catchments is usually higher than that of upper continental crust (UCC), China soil (CS) and world soil (WS). The ability of enrichment and release of U is partly controlled by content of U in bedrocks, contents and adsorption ability of clay minerals and Fe-oxides/hydroxides in weathering profiles. Our study also reveals that release of U mainly from weathering of limestone and partly from weathering of dolomite and clastic rocks exerts an important control on riverine U distribution. PMID:17326439

Song, Zhao-Liang; Liu, Cong-Qiang; Han, Gui-Lin; Wang, Zhong-Liang; Yang, Cheng; Liu, Zhan-Min

2006-11-01

42

In situ and experimental evidence for acidic weathering of rocks and soils on Mars  

NASA Astrophysics Data System (ADS)

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 surface 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 water 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 water to rock ratio alteration relationships developed for Gusev rocks. Soils are affected principally by mobility of Fe and Mg, consistent with alteration of olivine-bearing basalt and subsequent precipitation of Fe- and Mg-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. W.; Schröder, C.; Squyres, S. W.

2006-01-01

43

Preliminary study on weathering and pedogenesis of carbonate rock  

Microsoft Academic Search

South China is the largest continuous distribution area of carbonate rock in the world. The origin of the soils over the bedrock\\u000a carbonate rock has long been a controversial topic. Here further exploration is made by taking five soil profiles as examples,\\u000a which are developed over the bedrock dolomitite and limestone and morphologically located in upland in karst terrain in

Shijie Wang; Hongbing Ji; Ziyuan Ouyang; Dequan Zhou; Leping Zhen; Tingyu Li

1999-01-01

44

Identification of rock weathering and environmental control in arid catchments (northern Xinjiang) of Central Asia  

NASA Astrophysics Data System (ADS)

Chemical weathering is an integral part of the earth surface processes, whose spatial patterns and controlling factors on continental scale are still not fully understood. Highlands of the Asian continent have been shown having some of the highest observed rates of chemical weathering yet reported. However, the paucity of river gauge data in many of these terrains has limited determination of chemical weathering budget in a continental scale. A dataset of three large watersheds throughout northern Xinjiang in Central Asia is used to empirically identify chemical weathering regimes and interpret the underlying controlling factors. Detailed analysis of major ion ratios and a forward model of mass budget procedure are presented to distinguish the relative significances and contributions of silicate, carbonate weathering and evaporite dissolution. The analytical results show that carbonic acid is the most important weathering agent to the studied watersheds. Silicate weathering contributes, on average, ˜17.8% (molar basis) of total cations on a basin wide scale with an order of Zhungarer > Erlqis > Yili, indicating that silicate weathering, however, does not seem to be intense in the study basins. Evaporite dissolution, carbonate weathering and precipitation input contribute 43.6%, 29.7% and 8.9% of the total dissolved cations on average for the whole catchment, respectively. The three main morphological and hydrological units are reflected in water chemistry. Rivers from the montane areas (recharge area) of the three watersheds are very dilute, dominated by carbonate and silicate weathering, whereas the rivers of piedmont areas as well as the rivers of the sedimentary platform (runoff area) are dominated by carbonate weathering, and rivers of desert plain in the central Zhungarer basin (discharge area) are dominated by evaporite dissolution and are SO4 rich. This spatial pattern indicates that, beside lithology, runoff conditions have significant role on the regional chemical weathering regimes. Chemical weathering processes in the areas appear to be significantly climate controlled, displaying a tight correlation with runoff and aridity. Carbonate weathering are mostly influenced by runoff, which is higher in the mountainous part of the studied basins. The identification of chemical weathering regimes from our study confirmed the weathering potential and complexity of temperate watersheds in arid environment and that additional studies of these terrains are warranted. However, because the dominant weathering reactions in the sedimentary platform of northern Xinjiang are of carbonates and evaporites rather than silicate minerals, and the climatic factors have important role on the rock weathering regimes, we think that weathering at the arid temperate drainage system (Central Asia) is maybe not an important long-term sink for atmospheric CO2, if the future climate has no great change.

Zhu, Bingqi; Yu, Jingjie; Qin, Xiaoguang; Rioual, Patrick; Zhang, Yichi; Liu, Ziting; Mu, Yan; Li, Hongwei; Ren, Xiaozong; Xiong, Heigang

2013-04-01

45

The influence of petrophysical properties on the salt weathering of porous building rocks  

Microsoft Academic Search

The influence of pore structure, water transport properties and rock strength on salt weathering is evaluated by means of\\u000a a thorough rock characterisation and a statistical analysis. The pore structure was described in terms of its porosity, pore\\u000a size distribution (quantified by mean pore radius) and specific surface area, density and water transport was characterised\\u000a by means of water permeability

D. Benavente; N. Cueto; J. Martínez-Martínez; M. A. García del Cura; J. C. Cañaveras

2007-01-01

46

Effect of groundwater and sea weathering cycles on the strength of chalk rock from unstable coastal cliffs of NW France.  

E-print Network

1 Effect of groundwater and sea weathering cycles on the strength of chalk rock from unstable of ground water and sea weathering on the strength of the chalk rocks exposed on the coastline representative chalk units (Lewes Chalk, Seaford Chalk and Newhaven Chalk) exposed at various locations

Boyer, Edmond

47

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

48

The influence of petrophysical properties on the salt weathering of porous building rocks  

NASA Astrophysics Data System (ADS)

The influence of pore structure, water transport properties and rock strength on salt weathering is evaluated by means of a thorough rock characterisation and a statistical analysis. The pore structure was described in terms of its porosity, pore size distribution (quantified by mean pore radius) and specific surface area, density and water transport was characterised by means of water permeability (saturated flow) and capillary imbibition (unsaturated flow); whilst the rock strength test was carried out using uniaxial compressive strength, compressional and shear wave velocities, dynamic elastic constants and waveform energy and attenuation were obtained from the digital analysis of the transmitted signal. A principal component analysis and a stepwise multiple regression model was carried out in order to examine the direct relationships between salt weathering and petrophysical properties. From the principal component analysis, two main components were obtained and assigned a petrophysical meaning. The first component is mostly linked to mechanical properties, porosity and density whereas the second component is associated with the water transport and pore structure. Salt weathering, quantified by the percentage of weight loss after salt crystallisation, was included in both principal components, showing its dependence on their petrophysical properties. The stepwise multiple regression analysis found that rock strength has a predominant statistical weight in the prediction of salt weathering, with a minor contribution of water transport and pore structure parameters.

Benavente, D.; Cueto, N.; Martínez-Martínez, J.; García Del Cura, M. A.; Cañaveras, J. C.

2007-03-01

49

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

PubMed

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

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

2013-06-18

50

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

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

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

PubMed

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

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

2001-05-01

53

Turning rock into saprolite: Linking observations and models of vadose zone dynamics and chemical weathering  

NASA Astrophysics Data System (ADS)

Chemical weathering of rock into saprolite requires contact between water and unweathered rock, which occurs frequently but discontinuously in the unsaturated zone. Saprolite is a direct precursor to mobile regolith, and the distribution and rate of saprolite development play a role in sediment production on hillslopes. We strive to understand both the timing and spatial distribution of saprolite development in the subsurface, which is controlled by the delivery of fresh water to unweathered rock. We hypothesize that climate has a strong control on delivery of water to saprolite in the vadose zone, and hence on the rate of saprolite formation. In addition, the rate of water delivery is strongly modulated by the local fracture field, lending a strong heterogeneity to water delivery and weathering rates. To test this hypothesis, we link observations of moisture content in soil and saprolite with a numerical model of vadose zone dynamics. The moisture measurements are taken in the Boulder Creek watershed in central Colorado. This 1160 km2 catchment, which is underlain by fractured crystalline rocks (mainly granodiorite), ranges in elevation from high alpine peaks at 4120 m to the Colorado piedmont at 1480 m. The complex hydrologic architecture of the unsaturated zone necessitates a model that can incorporate multiple permeabilities to represent the variable flow paths in the soil, saprolite, and fractures. Therefore, we employed VS2DI, a Richards equation-based model, on two-dimensional hillslopes to visualize flow paths in the unsaturated zone and calculate volumetric moisture content at observation points. We ran multiple simulations investigating the relative roles of fracture spacing and variable timing and intensity of precipitation. Model experiments suggest that fractures are the primary pathway for delivering water deep below the subsurface. Where fracture density is higher, more water is delivered to the deep subsurface, allowing more chemical weathering at depth. Our results also indicate that both the intensity and total magnitude of precipitation events affect the flow paths of water in the subsurface. The effects of water flux in the subsurface on chemical weathering are modeled using a linear first-order reactive-transport model for albite dissolution. This reactive-transport model reveals the importance of timing and magnitude of precipitation on chemical weathering rates, as well as the importance of fractures on the spatial distribution of weathering in the unsaturated zone. The results indicate that the development of saprolite is strongly controlled by the temporal distribution of precipitation throughout the year. Water reaches deeper into unweathered rock when precipitation is concentrated during one season rather than being evenly distributed throughout the year. This finding suggests an intriguing link between the saprolite development and changing climate in mountain environments.

Langston, A. L.; Tucker, G. E.; Anderson, R. S.; Anderson, S. P.

2011-12-01

54

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

55

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

NASA Astrophysics Data System (ADS)

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. CO 2, 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, Art F.; Bullen, Thomas D.; Vivit, Davison V.; Schulz, Marjorie S.; Clow, David W.

1999-07-01

56

Release of uranium and thorium from granitic rocks during in situ weathering and initial erosion  

E-print Network

and gamma ray spectrometry. In unweathered or slightly weathered rocks, the mode of U occurrence in the Town Mountain-type granites (biotite 10%, U = 4 ppm) differ from the Bear Mountain granite (biotite = 1%, U = 33 ppm) . Both granites contain readily... be present as: (1) isomorphous substitution in the lattice; (2) local concentrations in lattice defects; (3) adsorption along crystal imperfections and grain boundaries; and (4) inclusions as microcrystals of U minerals. The U-zircon association...

Ledger, Ernest Broughton

1978-01-01

57

Weathering products of basic rocks as sorptive materials of natural radionuclides  

SciTech Connect

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

Omelianenko, B.I.; Niconov, B.S.; Ryzhov, B.I.; Shikina, N.D. [AN SSSR, Moscow (Russian Federation). Inst. Geologii Rudnykh Mestorozhdenij, Petrografii, Mineralogii i Geokhimii

1994-06-01

58

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

NASA Astrophysics Data System (ADS)

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 widely observed in modern environments but is not included in the supergene carbon budget. Using a digitized map of the world and an existing model of CO 2 consumption associated with rock weathering, we establish the global distribution of FOC stored in the first meter of sedimentary rocks and a first estimation of annual FOC delivery to the modern environment resulting from chemical weathering of these rocks. Results are given for the world's 40 major river basins and extended to the entire continental surface. With a mean value of 1100 10 9 t, mainly controlled by shale distribution, the global FOC stock is significant and comparable to that of soil organic carbon (1500 10 9 t). The annual chemical delivery of FOC, estimated at 43 10 6 t yr - 1 and controlled by the areal distribution of shales and runoff, is of the same order of magnitude as the FOC output flux to oceans. Chemical weathering of bedrock within the Amazon basin produces one-quarter of the total global flux of FOC derived from chemical weathering, and thus is expected to govern FOC release on a global scale. These results raise important questions concerning the role of FOC in the modern carbon cycle as well as the origin and the budget of carbon in soils and rivers.

Copard, Yoann; Amiotte-Suchet, Philippe; Di-Giovanni, Christian

2007-06-01

59

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

60

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

61

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

62

Weather  

NSDL National Science Digital Library

This lesson is written for fourth grade students. Students will explore weather and the effects it has on their lives. What is weather? video of what is weather Let's take a walk through the weather. Put on your hats and coats! Clouds Cloud Types Clouds - Dan's Wild Weather Page What to Wear? What to Wear? What to Drink? Weather Patterns and Climatic Regions ...

Ms. Bullough

2010-06-24

63

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 ...

Ms. Stearns

2008-10-25

64

Weather  

NSDL National Science Digital Library

Learn all about the aspects of weather that effect us every day. Click here to see a weather forecast for anywhere in the world World Wide Weather Watch See what happens to weather when you change conditions at your house Weather Maker Weather Games ...

Mrs. Hyde

2007-02-08

65

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 ...

Ms. Williams

2005-10-25

66

International Symposium on Hydrogeology and the Environment, Wuhan, China, Oct. 17 20, 2000 A confined groundwater zone in weathered igneous rocks and its impact  

E-print Network

A confined groundwater zone in weathered igneous rocks and its impact on slope stability Jiu Jimmy Jiao in igneous rock saprolites are a serious natural hazard in Hong Kong and have been extensively studied groundwater zone may exist in the weathered igneous rock profile due to a highly fractured zone. In Hong Kong

Jiao, Jiu Jimmy

67

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

PubMed

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

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

2014-09-11

68

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

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

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

NASA Technical Reports Server (NTRS)

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

Gooding, J. L.

1978-01-01

71

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. ...

Miss Jennie

2009-10-22

72

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

NASA Astrophysics Data System (ADS)

Increased environmental risk is incurred with expansion of mineral extraction in the Arctic. A greater understanding of geochemical processes associated with hard-rock mining in this cold climate is needed to evaluate and mitigate these risks. A laboratory and in-situ experiment was conducted to examine mineral weathering and the generation of acid rock drainage in a low-sulfide, run-of-mine waste rock in an Arctic climate. Rock with different concentrations of sulfides (primarily pyrrhotite [Fe7S8] containing small amounts of Co and Ni) and carbonates were weathered in the laboratory and in-situ, large-scale test piles to examine leachate composition and mineral weathering. The relatively larger sulfide-containing rock produced sufficient acid to overcome carbonate buffering and produced a declining pH environment with concomitant release of SO4, Fe, Co, and Ni. Following carbonate consumption, aluminosilicate buffering stabilized the pH above 4 until a reduction in acid generation. Results from the laboratory experiment assisted in determining that after consumption of 1.6 percent of the total sulfide, the larger sulfide-concentration test pile likely is at an internal steady-state or maximal weathering rate after seven years of precipitation input and weathering that is controlled by an annual freeze-thaw cycle. Further weathering of the test pile should be driven by external factors of temperature and precipitation in this Arctic, semi-arid region instead of internal factors of wetting and non-equilibrium buffering. It is predicted that maximal weathering will continue until at least 20 percent of the total sulfide is consumed. Using the identified evolution of sulfide consumption in this Arctic climate, a variable rate factor can now be assessed for the possible early evolution and maximal weathering of larger scale waste-rock piles and seasonal differences because of changes in the volume of a waste-rock pile undergoing active weathering due to the freeze-thaw cycle. Such rate factors are necessary to predict acid rock drainage and implement best management practices to minimize environmental impacts. To better understand the early geochemical evolution of the waste rock, sulfide minerals from different periods in the experiments were analyzed for discrete mineral characteristics indicative of a weathered state. Element transfer from the mineral to aqueous phase is transport limited because of the formation of Fe-(oxy)hydroxide weathered rims that can be an inhibitor of dissolution. Application of various x-ray spectroscopy techniques indicated that pyrrhotite transforms to marcasite [FeS2] prior to formation of Fe(II)-(oxy)hydroxides and further to Fe(III)-hydroxide/oxides. Iron appears to migrate through the weathered rims leaving the S-rich layer behind, and oxygen likely is retarded from migrating inward with formation of Fe(III) species. As these Fe-mineral transformations occur, they influence the retention of the secondary metals such as Co and Ni that preferentially remain in the +2 oxidation state and may leave the system as hydroxides, oxides, and sulfates. Understanding mineral evolution in this climate assists in adjusting appropriate rate factors for temporal changes in element release from the weathering of the pyrrhotite.

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

2013-12-01

73

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. PMID:23793627

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

2013-01-01

74

Excavatability Assessment of Weathered Sedimentary Rock Mass Using Seismic Velocity Method  

SciTech Connect

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; Noor, Muhazian Md; Isa, Mohamed Fauzi Bin Md.; Mazlan, Ain Naadia [Department of Geotechnics and Transportation, Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai. Johor (Malaysia); Saad, Rosli [Universiti Sains Malaysia, Penang (Malaysia)

2010-12-23

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

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

78

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

PubMed

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

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

2004-09-01

79

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 ...

Ms. Lauren

2010-11-17

80

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

81

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

82

Weathering  

NSDL National Science Digital Library

This interactive Flash resource provides information regarding physical and chemical weathering at an introductory physical geology or Earth science level. It includes animations, diagrams, and supplementary information and is suitable for high school or undergraduate students.

Smoothstone

83

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, ...

Mrs. Woodruff

2010-06-21

84

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

85

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

86

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 ...

Ms. Caitlin

2009-10-21

87

Rare earth element trends and cerium-uranium-manganese associations in weathered rock from Koongarra, Northern Territory, Australia  

NASA Astrophysics Data System (ADS)

At Koongarra, Australia, three drill cores from the Cahill Schist Formation containing U-ore, and regolith above it containing secondary U-ore, were studied to ascertain the distribution of rare earth elements (REEs) and U. The unaltered schist has a REE trend similar to the Post Archaean Australian Shale (PAAS), which is, therefore, used as a normalising standard. Unweathered rock from the zone of primary U mineralisation contained strong enrichment of the heavy REEs, and this pattern is retained during most of the weathering. Strongly bleached and very weathered shallow samples from this zone do not show enrichment of HREEs. In general, however, weathering appears to have little effect on the pattern of REEs in the bulk rock at this site. Zones rich in Mn oxy-hydroxides, occurring as coatings on fissure surfaces, contain large concentrations of Ce and U, with a clear Ce anomaly (Ce/ Ce * = 3.8). The Ce and U apparently occur together as microcrystalline oxides within (1-2 ?m diameter) globules on mineral surfaces in the Mn-rich zones.

Koppi, Anthony J.; Edis, Robert; Field, Damien J.; Geering, Harold R.; Klessa, David A.; Cockayne, David J. H.

1996-05-01

88

Nutrient Release from Weathering of Purplish Rocks in the Sichuan Basin, China 1 1 Project supported by the National Basic Research Program of China (No. 2003CB415202) and the National Natural Science Foundation of China (Nos. 40571093 and 49601009)  

Microsoft Academic Search

Purplish soils having high fertility with mineral nutrients inherited from the parent rock are widely distributed in the hills along the Yangtze River, especially in the Sichuan Basin. Pot and field weathering experiments were conducted to mimic rock weathering and nutrient release processes in order to better understand soil fertility and nutrient compensation. Three types of purplish rock formations formed

Bo ZHU; Tao WANG; Xiang YOU; Mei-Rong GAO

2008-01-01

89

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

90

SPACE WEATHERING OF ROCK SURFACE WITHOUT REGOLITH: LABORATORY SIMULATION OF SPECTRAL CHANGE, S. Sasaki1  

E-print Network

of nanophase metallic iron particles [1], existence of which wa confirmed in the rim of lunar soil grains [2- 4 are explained by the so-called "space weathering". One proven mechanism of such spectral change is production

Hiroi, Takahiro

91

Weathering: the decay of rocks and the source of sediments inand the source of sediments in  

E-print Network

SiO4 (silicic acid) #12;Hydration · A mineral reacts with either the H+ or the OH- (hydroxide) from water to produce a( y ) p new mineral. Aluminum silicates do not dissolve in water. Feldspars weather: quartz clay aluminum oxides· Most stable: quartz, clay, aluminum oxides (bauxite), iron oxides. #12

Kammer, Thomas

92

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,

93

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

94

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

95

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

96

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

97

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.

Wendy Harrison

98

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

99

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

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

100

Efficacy of nanolime in restoration procedures of salt weathered limestone rock  

NASA Astrophysics Data System (ADS)

Salt crystallisation process is one of the most powerful weathering agents in stone materials, especially in the coastal areas, where sea-spray transports large amount of salts on the stone surface. The consolidation of such degraded stone material represents a critical issue in the field of restoration of cultural heritage. In this paper, the nanolime consolidation behaviour in limestone degraded by salt crystallization has been assessed. For this purpose, a stone material taken from a Sicilian historical quarry and widely used in the eastern Sicilian Baroque architecture has been artificially degraded by the salt crystallization test. Then degraded samples have been treated with NanoRestore®, a suspension of nanolime in isopropyl alcohol. To evaluate the consolidating effectiveness, the peeling test and point load test were performed. Moreover, mercury intrusion porosimetry has been executed to evaluate the variations induced by treatment, while colorimetric measurements have been aimed to assess aesthetical issues.

Ruffolo, Silvestro A.; La Russa, Mauro F.; Aloise, Piergiorgio; Belfiore, Cristina M.; Macchia, Andrea; Pezzino, Antonino; Crisci, Gino M.

2014-03-01

101

Rocks  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. This lesson focuses on sedimentary rocks and how they are formed. Students review the rock cycle and three rock types: igneous, metamorphic and sedimentary. They then write children's books about sedimentary rocks to explain the process to a younger audience. Included are objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. Also available are videos which complement this lesson, audio vocabulary, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

2007-12-12

102

Fracture characteristics in weathered granites  

Microsoft Academic Search

The variability of weathered materials is an important factor in the geotechnical characterization of rock for engineering purposes. Most engineering rock mass classifications include weathering schemes that separate the weathering profile into zones or grades that depend upon the engineering and geological properties of the rock. Many geotechnical characteristics, including weathering, are controlled by the density and arrangement of fractures

Judy Ehlen

1999-01-01

103

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.

Mission Science Workshop

2013-01-01

104

Chemical Weathering  

NSDL National Science Digital Library

This tombstone weathering lab is designed to provide students with tangible understanding of chemical weathering and weathering rates. To prepare for this lab, students will have learned in previous labs to identify common minerals and rocks and will have attended lectures about the process of chemical weathering. During the first part of the lab we travel to the city cemetery to collect data on the age and extent of chemical weathering of tombstones that are made of limestone and igneous rocks. After collecting data for ~1 hour, we return to the computer lab where students use Microsoft Excel to analyze and interpret their data. Their task is to calculate a chemical weathering rate for limestone for our region and compare that rate to those from other regions. This activity gives students experience in the process of scientific inquiry: data collection, data analysis and data interpretation. Students develop Microsoft Excel skills: writing formulas, producing charts, understanding trendlines and R2 values.

Kira Lawrence

105

The Crayon Rock Cycle  

NSDL National Science Digital Library

In this activity, learners use crayons to draw conclusions about rocks and the rock cycle. Learners form crayons ((which can be "weathered"—heated, compressed and cooled—like rocks) into models of sedimentary, metamorphic, and igneous rocks.

Eric Muller

2004-01-01

106

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

107

Schmidt Hammer studies in the maritime Antarctic: Application to dating Holocene deglaciation and estimating the effects of macrolichens on rock weathering  

NASA Astrophysics Data System (ADS)

In order to contribute to the reconstruction of the deglaciation history of the Marguerite Bay area (~ 68°S, Maritime Antarctic) and to estimate the rock weathering rate in this Antarctic sector, 28 sites (7 on Rothera Point and 21 on Anchorage Island) were characterised using Schmidt Hammer values. The weathering effect of two of the most widespread species of macrolichens in this area (Usnea sphacelata and Umbilicaria decussata) was tested at 5 different sites on Rothera Point. Schmidt Hammer data, in conjunction with recent 14C age, suggest a deglaciation age for the Marguerite Bay area of around 12 ka, and an average uplift rate of 5.4 mm year- 1 on Anchorage Island for the period between 3.3 and 5.2 ka. The weathering rates are extremely slow (e.g. three times slower than reported in Norway). Our data confirm that lichens exert a strong impact on weathering, decreasing the Schmidt Hammer R-values on lichenised surfaces by a factor of 3-4 compared to bare rock surfaces. The effect of lichens on weathering is mainly due to edaphic conditions and the type of the lichen involved rather the period of exposure.

Guglielmin, M.; Worland, M. R.; Convey, P.; Cannone, N.

2012-06-01

108

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

109

Sedimentary RocksSedimentary Rocks Geology 200  

E-print Network

Sedimentary RocksSedimentary Rocks Geology 200 Geology for Environmental ScientistsGeology for Environmental Scientists #12;Major Concepts · Sedimentary rocks form by the processes of weathering, erosion · Sedimentary structures are critical to interpreting sedimentary rocks. #12;The Rock CycleThe Rock Cycle #12

Kammer, Thomas

110

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

SciTech Connect

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

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

1986-09-01

111

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

NASA Astrophysics Data System (ADS)

Work is devoted to the study of volcano sedimentary hydrothermally altered rocks in Geyser Valley (Kamchatka peninsula, Russia). The Geyser Valley is one of the most unique nature objects in Russia. There are quite large geyser fields. The valley of the river is part of the Uson-Geysernaya depression, where hydrothermal activity is very high. Besides geysers here are hot springs, mud pots and fumarols. In the late Pleistocene (about 45-35 thousand years ago) the lake was located in the site of the modern valley of the Geysernaya river, where sediments accumulated intensively. Sedimentary material came from several sources in the form of pyroclastic flows, ash falls, was supplied by permanent and temporary water streams. The total deposit thickness reached several hundred meters. In the late Pleistocene there was breakthrough of reservoir and further conditions for the lacustrine deposits formation did not arose. Later the rocks were intensively processed by thermal water. In 2007 large landslide was formed in lower part of the Geysernaya River on their left slope. Deposits of Geysernaya (Q34grn) series and Pemsovaya (Q34pmz) series were involved in landslide displacement. The headscarp was formed up to 100 m and a length of 800 m, exposing the volcano-sedimentary section of hydrothermally altered rocks - a unique opportunity for sampling and subsequent laboratory study. Thickness of lake sediments is interbedding of coarse-grain, medium-grain, fine-grain tuffites predominantly acidic composition. The study of thin sections revealed that all samples are lithoclastic and vitroclastic hydrothermally altered tuffits. Currently, the primary minerals and volcanic glass is largely replaced by clay minerals of the smectite group. Pores and cracks are made zeolites (heulandite and clinoptilolite). All this points to the low-temperature (<200 ° C) hydrothermal conditions with a pH near neutral. Tyere are acid plagioclase and quartz in most samples The high content of smectite causes high hygroscopy of deposits. Rocks are highly porous - of 37-65%, primarily low density - 0,9-1,65 g/cm3 wave velocities - from 0.74 km/s for porous to 3.42 km/sec for dense varieties. All samples are characterized by low strength characteristics: uniaxial compressive strength - 1.2 - 21.7 MPa, uniaxial tension - 0,6-4,7 MPa. By water saturation strength decreases rapidly. Soft coefficient ranges from 0.22 to 0.57. Proving to be on the land surface as a result of slope deformation, volcanic-sedimentary hydrothermally altered rocks are destroyed quickly by precipitation and temperature fluctuations Rock turned to sand, silt and clay depending on the original composition. It was found that often weathered to clayey state tuffites inherit structural and textural features of the primary species. The composition also varies: increased content of clay minerals (to 90%), decreasing the content of zeolites (not to exceed 10%). Quartz and plagioclase form sans fraction. Physical and mechanical properties vary widely: the density of the soil increases slightly up to 1,57-1,59 g/cm3 for sands, 1,2-1,79 g/cm3 for clays, porosity of 51-52% and 49-78% respectively, moisture 22-23% and 43-98/ Clays are in a state of semi-solid to fluid. The high content of smectite determines high plastic properties. Plasticity Index varies widely from 11 to 57. Cohesion and the internal friction angle obtained from shear tests also change widely. For clayey sand grip reaches 137 kPa, internal friction angle - 17 degrees. In clay grip ranges from 13 kPa to 120 kPa, and the internal friction angle - from 11 degrees to 31 degrees. Large variation of properties of the investigated soils is explained by the inhomogeneity of volcano-sedimentary formations both vertically and laterally, varying degrees of hydrothermal alteration and of weathering, fracturing and cracks filling The obtained datas can adequately characterize the volcanic-lacustrine sediments in the valley of the Geysernaya river and use them in calculations of slope stability and for and geological mapping.

Gvozdeva, Irina; Zerkal, Oleg; Samarin, Evgeny

2013-04-01

112

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

NASA Astrophysics Data System (ADS)

In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between - 3.7 and - 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze-thaw events were negligible (0-3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual temperature is - 3 °C. Permafrost thickness was calculated to range between 112 and 157 m, depending on the heat flow values adopted. The presence of sub-sea permafrost cannot be excluded considering the depth of the shelf around Rothera Point and its glacial history.

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

2014-11-01

113

Sedimentary Rocks  

NSDL National Science Digital Library

This interactive lesson about sedimentary rocks begins with weathering and sediments and shows a sediment size chart. Next, it covers the three processes by which sediments are changed to rock: compaction, cementation, and recrystallization. Stream deposits along with the difference between clastic and non-clastic rocks are discussed and the formation of coal, shale, sandstone, limestone, conglomerate, and breccia is explained.

114

Rocks, Rocks, Rocks!  

NSDL National Science Digital Library

What are the three types of rocks in the earth? Miss Rogers will hand out this chart. Compare and contrast the three rock types as you read. Three-circle Venn Diagram Record what you learn for each type of rock (IGNEOUS, SEDIMENTARY, METAMORPHIC). 3 Types of Rocks Watch this video. Rock Video Read about the rock cycle. Think about what objects in our classroom could represent the rock cycle. The Rock Cycle Read over the activity we ...

Miss Rogers

2011-10-26

115

External Resource: Rocks  

NSDL National Science Digital Library

This interactive animation by the British Broadcasting Corporation allows students to learn that rocks are all very different. It also shows students how rocks are formed. Topics: rock cycle, sedimentary, metamorphic, igneous, weathering, time.

1900-01-01

116

Gravestone Weathering  

NSDL National Science Digital Library

In this activity (located on pages 9-14 of PDF), learners visit a cemetery to examine the distinguishing characteristics of rock weathering. After researching stone weathering and acid rain, learners apply their knowledge to collect data related to chemical decomposition and physical disintegration at a cemetery site. This detailed lesson guide includes tips for educators, pre/post activity suggestions, hands-outs, and background information.

2012-06-26

117

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. PMID:24831147

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

2014-01-01

118

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

NASA Astrophysics Data System (ADS)

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 e.g. North American Shale Composite), the Chakrata pelites have high SiO 2, Al 2O 3, K 2O, Rb, Ba contents and low CaO, Fe 2O 3t, TiO 2, Sr, Sc, Ni and Cr concentrations. The REE abundances are high (up to 296 ppm) in pelites and reveal enriched LREE and depleted HREE patterns (La N/Yb N=7.9-11.1). Strong negative Eu anomalies are evident in the Chakrata pelites (Eu/Eu ?=0.46-0.58). The quartzites of the Chakrata Formation have high silica contents and low trace element abundances when compared to Phanerozoic sandstones. The chemical index of alteration values of these rocks ranges from 70 to 76, indicating intense weathering conditions in the source areas. Most pelites of the Chakrata Fm plot near the A-K line in the A-CN-K diagram which also suggests intense chemical weathering conditions. Major and trace element abundances and elemental ratios critical of provenance (e.g. high SiO 2/Al 2O 3, K 2O/Na 2O, La/Sc, Th/Sc, La/Yb and low Eu/Eu ? and Cr/Zr) suggest that the source rocks of these pelites were remarkably felsic in nature. The paleocurrent analyses reveal that the Chakrata pelites may have been derived from the granitoid rocks from the southerly direction (i.e. from Peninsular India). The geochemical similarities favour granitoid rocks from the Aravalli and Bundelkhand regions as the main source rocks for Chakrata sedimentary rocks.

Rashid, S. A.

2002-12-01

119

The influence of seasonal and local weather conditions on rock surface changes on the shore platform at Kaikoura Peninsula, South Island, New Zealand  

NASA Astrophysics Data System (ADS)

A traversing micro-erosion meter (TMEM) was used to measure micro-scale surface changes in a 45 cm 2 area of an intertidal mudstone shore platform on Kaikoura Peninsula, New Zealand, with hourly readings taken over 5 days for two seasons, within 4 h either side of low tide. For all monitoring events, the relative height of a total of 120 co-ordinates were obtained, resulting in 4200 and 4800 measurements for the summer and winter seasons respectively. Within seasons, samples were grouped according to the presence of rain or no rain. Significant changes were found in the micro-topography with variations in temperature and among rain and no rain sample groups. For both seasons, in the absence of rain, there were positive linear relationships between rock surface temperatures and rock surface elevations, and regression analysis explained 42.3% and 46.5% of this variation for the summer ( y = 0.098 + 0.004 x; p-value = 0.007) and winter ( y = 0.007 + 0.012 x; p-value < 0.001) seasons respectively. It is suggested that incorporating weather readings alongside measurements of surface change could not only improve extrapolations of shore platform erosion from short-term studies, but also differentiate fluctuations in rock surfaces due to changes in rock surface temperatures from other processes involved in shore platform erosion.

Hemmingsen, Sarah A.; Eikaas, Hans S.; Hemmingsen, Maree A.

2007-07-01

120

Weathering Experiments  

NSDL National Science Digital Library

This experiment is designed to allow students to observe and understand chemical and physical weathering of simulated "rocks". They will place the materials in plastic bags, one wet and one dry, and store them for 3-4 days. At the end of the storage period, they will observe the contents of both bags and answer some questions about what they see.

121

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

122

Rates of Chemical Weathering  

NSDL National Science Digital Library

In this activity, students will investigate the weathering of rocks by chemical processes. They will use effervescent cleansing tablets as a model for rock, and vary surface area, temperature, and acidity to see how rapidly the "rock" dissolves. This investigation will help them understand three of the factors that affect the rate of chemical weathering and develop better understanding of how to design controlled experiments by exploring only one experimental variable at a time.

Michael Passow

123

Rare earth element trends and cerium-uranium-manganese associations in weathered rock from Koongarra, Northern Territory, Australia  

Microsoft Academic Search

At Koongarra, Australia, three drill cores from the Cahill Schist Formation containing U-ore, and regolith above it containing secondary U-ore, were studied to ascertain the distribution of rare earth elements (REEs) and U. The unaltered schist has a REE trend similar to the Post Archaean Australian Shale (PAAS), which is, therefore, used as a normalising standard. Unweathered rock from the

Anthony J. Koppi; Robert Edis; Damien J. Field; Harold R. Geering; David A. Klessa; David J. H. Cockayne

1996-01-01

124

Determining the vertical evolution of hydrodynamic parameters in weathered and fractured south Indian crystalline-rock aquifers: insights from a study on an instrumented site  

NASA Astrophysics Data System (ADS)

Due to extensive irrigation, most crystalline aquifers of south India are overexploited. Aquifer structure consists of an upper weathered saprolite followed by a fractured zone whose fracture density decreases with depth. To achieve sustainable management, the evolution of hydrodynamic parameters (transmissivity and storage coefficient) by depth in the south Indian context should be quantified. Falling-head borehole permeameter tests, injection tests, flowmeter profiles, single-packer tests and pumping tests were carried out in the unsaturated saprolite and saturated fractured granite. Results show that the saprolite is poorly transmissive (T fs = 3 × 10-7 to 8.5 × 10-8 m2 s-1) and that the most conductive part of the aquifer corresponds to the bottom of the saprolite and the upper part of the fractured rock (T = 1.0 × 10-3 to 7.0 × 10-4 m2 s-1). The transmissivity along the profile is mostly controlled by two distinct conductive zones without apparent vertical hydraulic connection. The transmissivity and storage coefficient both decrease with depth depending on the saturation of the main fracture zones, and boreholes are not exploitable after a certain depth (27.5 m on the investigated section). The numerous investigations performed allow a complete quantification with depth of the hydrodynamic parameters along the weathering profile, and a conceptual model is presented. Hydrograph observations (4 years) are shown to be relevant as a first-order characterization of the media and diffusivity evolution with depth. The evolution of these hydrodynamic parameters along the profile has a great impact on groundwater prospecting, exploitation and transport properties in such crystalline rock aquifers.

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

2015-02-01

125

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.

2014-09-18

126

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,

127

Pathways of calcrete development on weathered silicate rocks in Tamil Nadu, India: Mineralogy, chemistry and paleoenvironmental implications  

NASA Astrophysics Data System (ADS)

Poorly documented yet spectacularly thick and extensive outcrops of calcrete hardpan occur on gneiss in the semiarid region of Coimbatore, South India. The hardpan caps a series of residual plateaux forming the present-day continental divide and grades into large expanses of Vertisols. Characteristic calcrete and Vertisol profiles were logged along toposequences and sampled for macro- and micromorphological study, and for chemical and mineralogical composition. Strontium isotopic analyses revealed that the calcrete is derived from in situ weathering of Ca-bearing primary minerals of the saprolite, which is rich in ankerite, Ca-amphiboles and Ca-plagioclase. The macroscale analysis revealed a range of facies developed within the gneiss saprolite, but in terms of relative chronology the nodular hardpan has the longest history. Two evolutionary pathways leading to nodular hardpan formation have been established. The first occurs entirely within a vadose environment, whereas the second begins within a phreatic environment before continuing to develop in vadose conditions. The ability to identify and map these generic categories of calcrete constitutes a potential tool for reconstructing paleotopography and paleogroundwater levels. The bedrock-weathering-derived nodular hardpan is blanketed by a laminar facies that correlates with an eolian event with marine Sr signatures. This suggests influx of Ca dust from the Arabian Sea continental shelf during a Pleistocene sea-level low-stand. It defines an important benchmark in the chronology of the area and highlights the potential antiquity of the thick calcrete profiles.

Durand, N.; Gunnell, Y.; Curmi, P.; Ahmad, S. M.

2006-11-01

128

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.

Pete Stelling

129

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.

Wendy Van Norden

130

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

131

Natural Weathering Rates of Silicate Minerals  

Microsoft Academic Search

Silicates constitute more than 90% of the rocks exposed at Earth's land surface (Garrels and Mackenzie, 1971). Most primary minerals comprising these rocks are thermodynamically unstable at surface pressure\\/temperature conditions and are therefore susceptible to chemical weathering. Such weathering has long been of interest in the natural sciences. Hartt (1853) correctly attributed chemical weathering to \\

A. F. White

2003-01-01

132

Precambrian Rocks in the Black Hills, SD  

USGS Multimedia Gallery

Precambrian rocks in the Black Hills of South Dakota. Precambrian rocks form the central crystalline core of the Black Hills. Fracturing and weathering in Precambrian rocks affect the availability of water in this unit....

133

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,

134

Yellowstone Weather  

NSDL National Science Digital Library

Yellowstone National Park's high altitude and mountainous terrain makes weather prediction very difficult. This website provides seasonal weather information, average temperature and precipitation data, links to weather forecasts, and other weather links.

Yellowstone National Park

135

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

136

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....

137

Effect of hot desert weathering on the bulk-rock iron isotope composition of L6 and H5 ordinary chondrites  

NASA Astrophysics Data System (ADS)

Although iron isotopes are increasingly used for meteorites studies, no attempt has been made to evaluate the effect of terrestrial weathering on this isotopic tracer. We have thus conducted a petrographic, chemical, and iron isotopic study of equilibrated ordinary chondrites (OC) recovered from hot Moroccan and Algerian Saharan deserts environment. As previously noticed, we observe that terrestrial desertic weathering is characterized by the oxidation of Fe-Ni metal (Fe0), sulfide and Fe2+ occurring in olivine and pyroxene. It produces Fe-oxides and oxyhydroxides that partially replace metal, sulfide grains and also fill fractures. The bulk chemical compositions of the ordinary chondrites studied show a strong Sr and Ba enrichment and a S depletion during weathering. Bulk meteoritic iron isotope compositions are well correlated with the degree of weathering and S, Sr, and Ba contents. Most weathered chondrites display the heaviest isotopic composition, by up to 0.1‰, which is of similar magnitude to the isotopic variations resulting from meteorite parent bodies' formation and evolution. This is probably due to the release of isotopically light Fe2+ to waters on the Earth's surface. Hence, when subtle Fe isotopic effects have to be studied in chondrites, meteorites with weathering grade above W2 should be avoided.

Saunier, Gaëlle; Poitrasson, Franck; Moine, Bertrand; Gregoire, Michel; Seddiki, Abdelmadjid

2010-02-01

138

Winter Weather  

MedlinePLUS

... Matters What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes Wildfires Winter Weather Winter Weather Language: English Español (Spanish) Recommend on Facebook Tweet ...

139

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

140

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

141

Thermal behaviour of weathered and consolidated marbles  

Microsoft Academic Search

To optimise stone consolidation it is necessary to understand the mechanisms of weathering in marbles, the control by the mineralogical composition and the rock fabric. The knowledge of how the stone consolidants affect the weathering mechanisms and if they are compatible with the stone is also an important consideration. The weathering of marble can begin with thermal stress whereby cracks

J. Ruedrich; T. Weiss; S. Siegesmund; E. K. Tschegg

2003-01-01

142

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

143

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

144

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 — from old weather proverbs to modern forecasting equipment — and how improvements in weather technology have saved lives by providing advance warning of natural hazards.

2014-09-18

145

UM Weather  

NSDL National Science Digital Library

Sponsored by The Weather Underground at the University of Michigan at Ann Arbor, UM Weather bills itself as the "Internet's premier source of weather information." The site offers several general audience tools such as the Fast Forecast for any city in the US, ski weather, and weather cams. But, it also provides access to over two dozen weather software packages, a new computer model forecasts page, and most impressively a list of close to 400 other weather related Web sites. Professionals and researchers will appreciate the non-technical feel of the site and the valuable information they can procure from it.

146

BBC Weather  

NSDL National Science Digital Library

At this website, the BBC offers an array of materials dealing with weather. Meteorologists can discover employment opportunities. Individuals with spectacular photographs of weather phenomenon can submit their images to the photo gallery. Students and educators can find introductory materials on basic weather concepts, forecasting, extreme events, and broadcasting the weather. The website offers fun weather-related games and projects, a meteorology glossary, and links to other educational websites.

147

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. ...

Mrs. Bellows

2009-09-28

148

Soil Genesis and Development, Lesson 1 - Rocks and Minerals  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

149

Soil creeping in the weathering crust of carbonate rocks and underground soil losses in the karst mountain areas of southwest china  

Microsoft Academic Search

Rocky desertification is of extensive occurrence in karst mountain areas, particularly in the areas where pure carbonate rocks\\u000a are underlying in Southwest China. Rocky desertification has great impacts on local social and economic development. This\\u000a paper puts its focus on the mechanism of rocky desertification and its deterioration due to human activities. Soil creeping\\u000a and sliding occur intensively in the

Xin-bao ZhangXiao-yong; Xiao-yong Bai; Xiu-bin He

2011-01-01

150

Weather Report  

NSDL National Science Digital Library

This printable weather report is designed to help students easily note a field site's important meteorological details. The one-page PDF form asks for the following information: date, temperature, precipitation, weather type, and wind speed (based on environmental clues).

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."

152

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.

153

Antarctic Weather  

NSDL National Science Digital Library

Visitors to this site can read a discussion about the weather in Antarctica, 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.

2010-01-01

154

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 Sanchez

2014-02-20

155

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. The National Weather Service (NWS)--which is part of NOAA and its parent agency, the Department of Commerce--is charged with the critical responsibility of observing and reporting the weather and with issuing forecasts and warnings of weather and floods in the interest of national safety and economy. Through a massive network of weather-monitoring and reporting stations around the globe, including land, sea, air, and space-borne instruments, NWS scientists constantly assimilate all of the reliable weather data available. Much of this data are then used in numerical computer models of the atmosphere that help to accurately describe and interpret current conditions and produce the best possible forecasts of future weather.

Evan B. Forde

2004-04-01

156

Three classes of Martian rocks  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

157

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

158

Sedimentary Rocks: Carbonate Rocks  

NSDL National Science Digital Library

Sedimentary Rocks: Carbonate Rocks is a course handout meant to accompany the discussion of chemical and biochemical sedimentary rocks. Rock composition is broken into the main categories of limestone and dolostone. Depositional conditions are discussed, including the topics of coral reefs, plankton, and carbonate compensation depth (CCD). There are a few photographs, which display calcareous algae. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Pamela Gore

159

Weather Data  

NSDL National Science Digital Library

The listed websites are recommended safe kid friendly sites that may be used when gathering data for the at home data project. Use the websites listed to learn more about daily weather patterns in different cities around the world. After you have collected and organized your data, create a graph representing the different weather patterns in that city. Use this site to record the daily high temperature for your assigned city. The Weather Channel Use this ...

Ms. Harris

2011-01-24

160

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.

161

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.

162

Weather Watch  

NSDL National Science Digital Library

The weather watch activity is designed to provide instruction on how to collect weather data from on-line databases. Following completion of this activity the user will be able to look up weather conditions for any city in North America, know what radar maps are used for and how to access them, and know how to access satellite images and make estimated guesses on cloud conditions for their area from them.

R. Hopson

163

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

164

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

165

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

166

Making & Breaking: The Rock Cycle  

NSDL National Science Digital Library

Students learn the components of the rock cycle and how rocks can change over time under the influence of weathering, erosion, pressure and heat. They learn about geotechnical engineering and the role these engineers play in the development of an area of land, the design and placement of new structures, and detection of natural disasters.

2014-09-18

167

Wacky Weather  

ERIC Educational Resources Information Center

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

Sabarre, Amy; Gulino, Jacqueline

2013-01-01

168

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.

169

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

170

Influence of Weathering on Physical and Mechanical Properties of Mudstone  

Microsoft Academic Search

Majority of the landslides in Niigata prefecture, Japan are occurred at Neogene sedimentary soft rocks. Weathering of such rocks is an important geological, environmental and engineering process. In order to study the chemical and physical weathering and their impact on the shear strength of the soil mass, soil samples were collected from ground surface to 15 m depth at two

Pankaj Bhattarai; Hideaki Marui; Binod Tiwari; Naoki Watanabe; Gyanu R. Tuladhar; Kiyomichi Aoyama

171

Rock Climbing  

NSDL National Science Digital Library

Join Jesse and Gordon on their rock climbing adventures. In this video you will learn about metamorphic, sedimentary, and igneous rocks. Learn what types of rocks are best for climbing and how to determine each rock type.

2006-01-01

172

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.

John Nielsen-Gammon

1996-09-01

173

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

174

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.

175

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.

Duane Friend

176

Winter Weather  

MedlinePLUS

... weather presents hazards including slippery roads/surfaces, strong winds and environmental cold. Employers must prevent illnesses, injuries, ... from surfaces) Use extreme caution when working near power lines Prevent harmful exposure to cold temperatures and ...

177

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

178

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

179

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

180

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.

181

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

182

Exploring Weather  

NSDL National Science Digital Library

Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday, February 1st: Look at the five-day forecast for Salt Lake City, Utah at Five day forecasts. The high temperature for the day will be in red and the low temperature will be in blue. Make sure you look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make ...

Miss Emily

2010-01-29

183

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

184

Rock-degrading endophytic bacteria in cacti  

Microsoft Academic Search

A plant–bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2, produce volatile and non-volatile organic acids, and reduce rock particle size to form mineral

M. Esther Puente; Ching Y. Li; Yoav Bashan

2009-01-01

185

Riverbank rock identification  

NSDL National Science Digital Library

This exercise is part of a field trip lab in which we see map different till deposits. At a small, meandering sand-bed river in Minnesota, students are directed to wander along the riverbank and pick up gravel-sized rocks. When they each have a handful, I lay a table-sized, laminated map of Minnesota bedrock geology on the ground. I ask the students to identify their rocks, then find the corresponding bedrock units on the map and throw their rocks down in those regions. Soon we have a pile of rocks in northwestern Minnesota into Canada (weathered shales, weathered limestones), northern and northeastern Minnesota (granites, gneisses, basalts and rhyolites if we are lucky) and central Minnesota (dolomite, sandstones, granites). This visually demonstrates that glaciers transported stones from many distant locations and brought them here to southern Minnesota. In addition, we talk about how the river is down-cutting through consecutive layers of till and mixing those particles together in the stream deposits. The exercise gives students practice in identifying rocks, reading maps, and synthesizing different fields of geology to answer a geomorphic question about glacial transport. Designed for a geomorphology course Has minimal/no quantitative component

Laura Triplett

186

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.

187

Salt weathering in dual-porosity building dolostones  

Microsoft Academic Search

The influence of rock fabric on physical weathering due to the salt crystallization of selected brecciated dolostones is discussed. These dual-porosity dolostones are representative of heterogeneous and anisotropic building rocks, and present highly complex and heterogeneous rock fabric features. The pore structure of the matrix and clasts is described in terms of porosity and pore size distribution, whereas the relative

D. Benavente; J. Martínez-Martínez; N. Cueto; M. A. García-del-Cura

2007-01-01

188

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

189

Wonderful Weather  

NSDL National Science Digital Library

Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday November 6th: Look at the five-day forecast for Logan Utah at Five Day Forecast in Utah. The high temperature for the day will be in red and the low temperature will be in blue. Look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make a bar graph for the ...

Ms. Broadhead

2007-11-06

190

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.

191

Weather Forecasting  

NSDL National Science Digital Library

In this online, interactive module, students will learn how to interpret weather patterns from satellite images, predict storm paths and forecast the weather for their area. 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.

192

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

193

Talking Rocks.  

ERIC Educational Resources Information Center

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

Rice, Dale; Corley, Brenda

1987-01-01

194

Rock Cycle  

NSDL National Science Digital Library

This site, from Moorland School in England, describes the rock cycle. Topics briefly discussed include rock formation, erosion, transportation, and deposition, plus various types of rocks. The page is directed towards a middle-school audience.

Moorland School

195

Rock, Paper, Scissors Probability!  

NSDL National Science Digital Library

Students learn about probability through a LEGO® MINDSTORMS® NTX-based activity that simulates a game of "rock-paper-scissors." The LEGO robot mimics the outcome of random game scenarios in order to help students gain a better understanding of events that follow real-life random phenomenon, such as bridge failures, weather forecasts and automobile accidents. Students learn to connect keywords such as certainty, probable, unlikely and impossibility to real-world engineering applications.

AMPS GK-12 Program,

196

Space Weather  

E-print Network

Space Weather :: Printer Friendly Version of Article 2005SW000176 http://www.agu.org/journals/sw/swa/feature/article/print.php?id=2005S... 1 of 5 07/07/2006 12:22 PM Shielding Space Explorers From Cosmic Rays Expert opinions-inducing radiation in space. Eugene N. Parker 18 August 2005 Any space traveler far removed from the protective

Shepherd, Simon

197

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.

2012-12-19

198

Wacky Weather  

NSDL National Science Digital Library

This 5-lesson unit gives students practice in using calculating, graphing and modeling skills to analyze varoius aspects of weather. Students calculate fractions of a set of rainfall data, graph damage costs of selected hurricanes, and make Venn diagrams to compare droughts and hurricanes. Visuals and student handouts are provided.

Barbara Chichetti

2002-01-01

199

Weather Alert  

NSDL National Science Digital Library

Students discuss the characteristics of storms, including the relationship of weather fronts and storms. Using everyday materials, they develop models of basic lightning detection systems (similar to a Benjamin Franklin design) and analyze their models to determine their effectiveness as community storm warning systems.

Integrated Teaching and Learning Program,

200

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.

Mission Science Workshop

2013-01-01

201

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.

202

Z .Chemical Geology 158 1999 189202 Bacterial effects on the mobilization of cations from a weathered  

E-print Network

a weathered Pb-contaminated andesite Jeremy B. Fein a,) , Patrick V. Brady b , Jinesh C. Jain a , Ronald I from a weathered andesite was examined by conducting water­rock leaching experiments to measure release

Dorn, Ron

203

Rock Hounds  

NSDL National Science Digital Library

At this site students will learn about rocks and rock collecting. They will learn about sedimentary, metamorphic, and igneous rocks and be provided with examples, information, and pictures for each of the three kinds of rocks. Students can take a quiz to see if they can remember which rock is sedimentary, metamorphic, or igneous. Site includes a Web-based lesson plan and rock activities. Students will learn about erosion, the elements of soil, how a sedimentary rock becomes a metamorphic rock, gemstones, minerals, and geology. They will be able to make a volcano and a rock collection, and participate in a rock swap. Site also includes information about rock safety and additional links.

Franklin Institute WiredSchool

2007-12-12

204

Weathering: methods and techniques to measure  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

205

National Weather Service  

MedlinePLUS

HOME FORECAST Local Graphical Aviation Marine Rivers and Lakes Hurricanes Severe Weather Fire Weather Sun/Moon Long Range Forecasts Climate Prediction PAST WEATHER Past Weather Heating/Cooling Days Monthly ...

206

Activities in Teaching Weather  

ERIC Educational Resources Information Center

Presented is a unit composed of activities for teaching weather. Topics include cloud types and formation, simple weather instruments, and the weather station. Illustrations include a weather chart and instruments. A bibliography is given. (MA)

Tonn, Martin

1977-01-01

207

Rock Solid  

NSDL National Science Digital Library

A teacher describes how developing a structured, focused, and fun curriculum on rocks and minerals for learning-disabled students transformed her initial reluctance about Earth science into enthusiasm. Students observed, described, and sorted rocks and explored rock formation. A sample worksheet is included, as is a list of children's trade books about rocks.

Katherine Sorel

2003-02-01

208

Igneous Rocks  

NSDL National Science Digital Library

This interactive lesson on igneous rocks begins with a comparison of intrusive and extrusive igneous rocks with diagrams to show their origin. This leads to a discussion of intrusive rock formations including dikes, sills, laccoliths and batholiths and a block diagram to show their location. Basaltic rocks are described to include basalt, pumice, and gabbro and are contrasted with granitic rhyolite and obsidian.

209

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 ...

Mrs. Mitchell

2010-09-23

210

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,

211

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

212

Rock Cycle  

NSDL National Science Digital Library

The Rock Cycle SciPack explores different kinds and categories of rocks, the major processes through which they form and the cyclical nature of the formation and transformation of rock materials. The focus is on topics supporting Standards and Benchmarks related to the rock cycle as part of the transfer and transformation of matter and energy in Earth's system as well as a sense of the time scales involved and how rocks provide information about their own development and the history of Earth.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:? Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. ? Access to one-on-one support via e-mail to content "Wizards".? Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Rock Cycle: Categories by Process? List the three different types of rock. ? Make appropriate observations about rocks (e.g. describe rock composition and texture).? Make appropriate observations about the general environments in which the rocks formed.Rock Cycle: Environments of Formation? 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.Rock Cycle: Cycling? Recognize the formation and transformation processes as part of a continuing cycle.? Identify that while the form and location of different rocks change over time, the amount of material and the distribution among the elements remains constant.? Explain the different processes or paths that each type of rock may take in the rock cycle.Rock Cycle: Earth's Autobiography? State the amount of time over which the rock cycle has been in operation (4 billion years rather than 40 million or 400 million).? Recognize that the processes at work in the present are the same as those at work in the distant past.? Describe how rock formations and characteristics can be used to determine how different rock formed, making appropriate interpretations about the source of the rock, history and processes, and the environment of formation.? Describe how rocks provide a history of the changing surface of Earth and its lifeforms.

National Science Teachers Association (NSTA)

2007-03-21

213

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

214

Lateral Variations in Lunar Weathering Patina on Centimeter to Nanometer Scales  

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.

2013-01-01

215

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 ...

Tiffany A. Lindsey

2010-06-21

216

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.

217

Weathering processes and landforms The International Encyclopedia of Geography: People, the Earth,  

E-print Network

ForReview Only Weathering processes and landforms Journal: The International Encyclopedia Keywords: Abstract: The International Encyclopedia of Geography: People, the Earth, Environment illustrate how the appearance of bare-rock landforms relates to rock decay. The last section details

Dorn, Ron

218

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

TERC. Center for Earth and Space Science Education

2003-01-01

219

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

220

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.

221

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.

222

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.

223

Cave development by frost weathering  

NASA Astrophysics Data System (ADS)

This paper deals with the description and genesis of a special type of shelter cave. In German they are termed Auswitterungshöhlen which goes back to the 19th century and the genesis is supposed to be related to frost weathering, but to our knowledge, detailed studies are missing so far. This type of cave is very common in the area of investigation that comprises pre-Alpine and Alpine regions in the north-eastern part of the Eastern Alps: They make up 32% of the 5138 registered caves but surprisingly they entirely developed in carbonate rocks. Although most of them are smaller than a dozen metres, some have lengths of more than 50 m and entrances can be more than 100 m wide or similarly high. Besides general observations that lead to a list of characteristics for these caves, two of them in a pre-Alpine setting were studied in-depth. A detailed map, descriptions, and measurements concerning cave morphology, host rock geology, and climate are given. The thickness and composition of clastic sediments were investigated by small trenches and electric resistivity measurements. Sediment thicknesses reach up to 2 m inside the caves and below the entrances. For one year nets were installed to measure rockfall in both caves. In warm periods generally less than 5 g/month of debris could be collected, but a few 100 g/month for frost periods. This strong correlation and the significant amount of debris together with other observations suggest that frost weathering is an on-going and very important process for the formation of these caves. Grain-size distribution of the collected debris argues for the activity of both microgelivation and ice segregation. Therefore we suggest that the term frost weathering caves should be used for shelter caves whose genesis is related to frost weathering. As dissolution seems to be of marginal importance for the genesis they are a paradox as they develop in karstic rock but have pseudokarst features.

Oberender, Pauline; Plan, Lukas

2015-01-01

224

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

225

Rock Pore Structure as Main Reason of Rock Deterioration  

NASA Astrophysics Data System (ADS)

Crashed or dimensional rocks have been used as natural construction material, decoration stone or as material for artistic sculptures. Especially old historical towns not only in Slovakia have had experiences with use of stones for construction purposes for centuries. The whole buildings were made from dimensional stone, like sandstone, limestone or rhyolite. Pavements were made especially from basalt, andesite, rhyolite or granite. Also the most common modern construction material - concrete includes large amounts of crashed rock, especially limestone, dolostone and andesite. However, rock as any other material if exposed to exogenous processes starts to deteriorate. Especially mechanical weathering can be very intensive if rock with unsuitable rock properties is used. For long it had been believed that repeated freezing and thawing in relation to high absorption is the main reason of the rock deterioration. In Slovakia for many years the high water absorption was set as exclusion criterion for use of rocks and stones in building industry. Only after 1989 the absorption was accepted as merely informational rock property and not exclusion. The reason of the change was not the understanding of the relationship between the porosity and rock deterioration, but more or less good experiences with some high porous rocks used in constructions exposed to severe weather conditions and proving a lack of relationship between rock freeze-thaw resistivity and water absorption. Results of the recent worldwide research suggest that understanding a resistivity of rocks against deterioration is hidden not in the absorption but in the structure of rock pores in relation to thermodynamic properties of pore water and tensile strength of rocks and rock minerals. Also this article presents some results of research on rock deterioration and pore structure performed on 88 rock samples. The results divide the rocks tested into two groups - group N in which the pore water does not freeze even when the temperature decreases to -20 ºC, and the second group F in which the pore water freezes. It has been found that the rocks from group N contain critical portion of adsorbed water in pores which prevents freezing of the pore water. The presence of adsorbed water enables thermodynamic processes related to osmosis which are dominantly responsible for deterioration of rocks from group N. A high correlation (R = 0.81) between content of adsorbed water and freeze-thaw loss was proved and can be used as durability estimator of rocks from group N. The rock deterioration of group F is caused not only by osmosis, but also by some other processes and influences, such as hydraulic pressure, permeability, grain size, rock and mineral tensile strength, degree of saturation, etc., and the deterioration cannot be predicted yet without the freeze-thaw test. Since the contents of absorbed water and ratio between adsorbed and bulk water (of which the absorbed water consists) is controlled by the porosity and pore structure, it can be concluded that the deterioration of some rocks is strongly related to rock pore structure.

Ondrášik, Martin; Kopecký, Miloslav

2014-03-01

226

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

Building a Weather-Ready Nation Winter Weather Safety NOAA/NWS Winter Weather Safety Seasonal Campaign www.weather.gov #12;Building a Weather-Ready Nation Winter Weather Hazards Winter Weather Safety www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

227

Rivers, chemical weathering and Earth's climate  

NASA Astrophysics Data System (ADS)

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 are of primary importance for numerical models calculating the evolution of the partial pressure of atmospheric CO 2 and the Earth climate at geological timescales. The major results can be summarized as follow: (1) weathering of continental basaltic lithologies accounts for about 30% of the total consumption of atmospheric CO 2 through weathering of continental silicate rocks. This is related to their high weatherability (about eight times greater than the granite weatherability); (2) a simple weathering law has been established for basaltic lithologies, giving the consumption of atmospheric CO 2 as a function of regional continental runoff, and mean annual regional temperature; (3) no such simple weathering law can be proposed for granitic lithologies, since the effect of temperature can only be identified for regions displaying high continental runoff; (4) a general law relating mechanical erosion and chemical weathering has been validated on small and large catchments. The consequences of these major advances on the climatic evolution of the Earth are discussed. Particularly, the impacts of the onset of the Deccan trapps and the Himalayan orogeny on the global carbon cycle are reinvestigated. To cite this article: B. Dupré et al., C. R. Geoscience 335 (2003).

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

2003-12-01

228

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.

John Pratte

229

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 ...

Mrs. Walls

2011-01-30

230

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,

231

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

232

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

233

Metamorphic Rocks  

NSDL National Science Digital Library

Here is an in-depth description of metamorphic rocks, from their classification to formation and identification. It covers types of metamorphism (including Barrovian, or regional rock changes), classification by foliation, and metamorphic processes (facies and zones). An alphabetical list of rocks with picture, composition, description, tectonic association, and type of metamorphism is given. Common metamorphic minerals are covered as well.

2007-12-12

234

Igneous Rocks  

NSDL National Science Digital Library

Create a poster about Igneous Rocks! Directions: Make a poster about Igneous 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 igneous rocks. (5 points each) (15 points) Write at least a three sentence summary ...

Mrs. Walls

2011-01-30

235

Collecting Rocks.  

ERIC Educational Resources Information Center

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

Barker, Rachel M.

236

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

237

Soil Genesis and Development, Lesson 2 - Processes of Weathering  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

238

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.

239

Radiogenic Isotopes in Weathering and Hydrology  

Microsoft Academic Search

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

J. D. Blum; Y. Erel

2003-01-01

240

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

Microsoft Academic Search

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

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

1991-01-01

241

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

Microsoft Academic Search

Abert Lake in south-central Oregon provides a site suitable for the study of sequential weathering and diagenetic events. In this first of two papers, transmission electron microscopy was used to characterize the igneous mineralogy, subsolidus alteration assemblage, and the structural and chemical aspects of silicate weathering reactions that occur in the volcanic rocks (basalts, basaltic andesites, and dacitic\\/ rhyolitic extrusive

Jillian F. Banfield; Blair F. Jones; David R. Veblen

1991-01-01

242

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

243

Salt-weathering simulations under hot desert conditions: agents of enlightenment or perpetuators of preconceptions?  

Microsoft Academic Search

Because of access difficulties and inhospitable environmental conditions, our understanding of rock weathering in hot deserts has been strongly influenced by laboratory simulations. However, a risk exists that results may come to owe more to experimental design than to actual environmental conditions experienced at the atmosphere\\/rock surface interface. This was especially true in early salt-weathering simulations that seemingly sought to

B. J. Smith; P. A. Warke; J. P. McGreevy; H. L. Kane

2005-01-01

244

Controlling The Global Weather.  

NASA Astrophysics Data System (ADS)

the weather controller is extremely complex, the existence of the required technology is plausible in the time range of several decades.While the concept of controlling the weather has often appeared in science fiction literature, this statement of the problem provides a scientific basis and a system architecture to actually implement global weather control. Large-scale weather control raises important legal and ethical questions. The nation that controls its own weather will perforce control the weather of other nations. Weather "wars" are conceivable. An international treaty may be required, limiting the use of weather control technology.

Hoffman, Ross N.

2002-02-01

245

Insolation Weathering: An Instrumentation and Field Based Study (Invited)  

Microsoft Academic Search

Processes of mechanical weathering related to diurnal insolation are largely unexplored. Recent studies (McFadden et al., 2005, Eppes et al., 2010) demonstrated that rocks in a range of environments exhibit preferentially orientated (~N-S) cracks that are hypothesized to form as rocks are heated and cooled during the sun's daily transit across the sky. In this study, we attempt to better

M. C. Eppes; K. Warren; S. Swami; K. Folz-Donahue; S. Evans; J. Cavendar; I. Smith; A. Layzell

2010-01-01

246

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

247

Earth Rocks!  

NSDL National Science Digital Library

The purpose of this lesson is to introduce students to the basic elements of our Earth's crust: rocks, soils and minerals. They learn how we categorize rocks, soils and minerals and how they are literally the foundation for our civilization. Students also explore how engineers use rocks, soils and minerals to create the buildings, roads, vehicles, electronics, chemicals, and other objects we use to enhance our lives.

Integrated Teaching and Learning Program,

248

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

249

Evolution of porosity and diffusivity associated with chemical weathering of a basalt clast  

E-print Network

Evolution of porosity and diffusivity associated with chemical weathering of a basalt clast Alexis in their chemistry and porosity. In low-porosity rocks, such as basalts, changes in porosity, resulting from chemical and effective porosity and effective diffusion coefficients across a weathering interface in a weathered basalt

250

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.

Lynn Fichter

251

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.

252

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

253

Lithium isotope history of Cenozoic seawater: changes in silicate weathering and reverse weathering.  

PubMed

Weathering of uplifted continental rocks consumes carbon dioxide and transports cations to the oceans, thereby playing a critical role in controlling both seawater chemistry and climate. However, there are few archives of seawater chemical change that reveal shifts in global tectonic forces connecting Earth ocean-climate processes. We present a 68-million-year record of lithium isotopes in seawater (?(7)Li(SW)) reconstructed from planktonic foraminifera. From the Paleocene (60 million years ago) to the present, ?(7)Li(SW) rose by 9 per mil (‰), requiring large changes in continental weathering and seafloor reverse weathering that are consistent with increased tectonic uplift, more rapid continental denudation, increasingly incongruent continental weathering (lower chemical weathering intensity), and more rapid CO(2) drawdown. A 5‰ drop in ?(7)Li(SW) across the Cretaceous-Paleogene boundary cannot be produced by an impactor or by Deccan trap volcanism, suggesting large-scale continental denudation. PMID:22282473

Misra, Sambuddha; Froelich, Philip N

2012-02-17

254

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

255

Relationship between mineral weathering and groundwater composition  

NSDL National Science Digital Library

In this pair of activities, students start by using published data to predict what will happen to groundwater composition as a consequence of chemical weathering. The data are provided in a spreadsheet (Hinman_weathering). Students are given the histograms only; both are normalized to 100 %, while one includes silica and the other does not. Students must use resources to predict how groundwater composition will change as a consequence of the observed weathering, and support those predictions using balanced chemical-weathering equations. Afterwards, they conduct a laboratory experiment in which they subject crushed rock to four types of solutions (acid solution, organic-rich solution, rainwater, and alkaline solution). The pH of each solution is measured, and subsequently adjusted after 24 and 48 hours. Solutions are sampled after 14 days. They are analyzed by ICP, and the compositions reported to students for comparison with their predictions.

Nancy Hinman

256

Yaquina Bay Weather & Tides  

E-print Network

Yaquina Bay Weather & Tides Clay Creech Phil Barbour #12;HMSC Weather Station #12;Temp-Humidity Sensor at Library #12;http://weather.hmsc.oregonstate.edu #12;#12;#12;#12;#12;#12;Archived Data is Available every 15 mins. #12;#12;A pyranometer measures solar radiation #12;#12;National Weather Service

Wright, Dawn Jeannine

257

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

258

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

259

Sedimentary Rocks  

NSDL National Science Digital Library

This overview of sedimentary rocks is part of an online historical geology class taught by Dr. Pamela J.W. Gore at Georgia Perimeter College. The outline format includes basic information about the different types and classifications of sedimentary rocks and their defining characteristics, sedimentary structures, and sedimentary environments. Photographs help illustrate the concepts by providing real-world examples.

Pamela J.W. Gore

260

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

261

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.

262

'Tetl' Rock  

NASA Technical Reports Server (NTRS)

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

2004-01-01

263

Rocks and Minerals  

NSDL National Science Digital Library

Rock Cycle Mineralogy 4 Kids Mineralogy 4 kids : rockin Internet site : the best place to learn about rocks and minerals Rock Cycle Map Rocks and Minerals Rocks and Minerals Pictures Rocks and Minerals Slide Show Rocks and Minerals Slide Show Earth Science Earth Science Uses for Minerals Metamorphic Rock Forming Sedimentary Rocks Observation ...

richrigby

2010-02-23

264

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.

265

Rock Mech. Rock Engng. (1999) 32 (2), 8199 Rock Mechanics  

E-print Network

Rock Mech. Rock Engng. (1999) 32 (2), 81±99 Rock Mechanics and Rock Engineering : Springer The microstructure of rock is known to in¯uence its strength and deformation characteristics. This paper presents thresholds of stress- induced brittle fracturing in crystalline rocks with similar mineralogical composi

266

Weather Camp 2012 "Weather and Climate All Around Us"  

E-print Network

Weather Camp 2012 "Weather and Climate All Around Us" Are you interested in the weather? Come to Weather Camp at UNL What is Weather Camp? For more information Weather camp is a week long day camp for students who will be 11-14 years old at the time of the camp Most of the activities at Weather Camp 2012

Farritor, Shane

267

Art Rocks with Rock Art!  

ERIC Educational Resources Information Center

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

Bickett, Marianne

2011-01-01

268

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

269

Terby's Rocks  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

270

External Resource: Rock and the Rock Cycle  

NSDL National Science Digital Library

This Windows to the Universe interactive site investigates the rock cycle and illustrates that over millions of years, rocks are recycled into other rocks. Topics: rock cycle, igneous, metamorphic, sedimentary, plate tectonics, and geologic time.

1900-01-01

271

Weather Information System  

NASA Technical Reports Server (NTRS)

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

1995-01-01

272

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

273

Space Weather FX  

NSDL National Science Digital Library

Space Weather FX is a vodcast (video podcast) series that explores the science of space weather and how it can impact our every day lives. Episodes include Space Weather and its Effects, Connecting the Sun and Earth, When Space Weather Attacks, Stratospheric Sudden Warming, A Tour of Haystack's Radars, GPS and Space Weather, It Came from the Sun, and The Big Picture. The site also contain links to space weather information and educational materials. The episodes will run on one of four free video players.

274

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? ...

Mrs. Emma Grasser

2012-09-27

275

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

276

Science Sampler: Weather RATS  

NSDL National Science Digital Library

Weather RATS, or Weather Research and Tracking Systems, is a collaborative effort among a national network of K-12 students, their teachers, wireless weather stations, internet data sharing, and professional engineers and meteorologists. Weather Rats is a new way to teach K-12 science and technology by tracking and comparing weather data from schools in Massachusetts, Arizona, Oklahoma, and Puerto Rico. In addition, it is hoped through this enriching project that Weather RATS will inspire many more students, especially girls and minorities, to pursue careers in science and engineering as a result of this project.

Mary Taft

2006-02-01

277

Rock Shots  

NSDL National Science Digital Library

Recently debuted on Adam Curry's METAVERSE site is Rock Shots, the first exclusive gallery of Rock 'n Roll photography on the Web by photographer Niels Van Iperen. Niels has been shooting musicians, fans and festivals for over 12 years in Europe and the U.S. His clients include the magazines Rolling Stone, Musician, Metal Hammer, OOR and Guitar World . Rock Shots brings you face to face with Aerosmith live in Brazil, Pearl Jam in their dressing room, the Red Hot Chili Peppers in a swimming pool and more ... on stage, backstage and audience rage. Portraits are viewed in Rock Shots through a custom-made search engine and is updated weekly with new artists.

Iperen, Niels van.

278

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

279

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.

Eric Muller

2003-01-01

280

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather?  

E-print Network

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather? Come to Weather Camp at UNL! What is Weather Camp? For more information Weather camp is a week-long day camp for students who will be 11-14 years old at the time of the camp. Most of the activities at Weather Camp 2012

Farritor, Shane

281

Winter Weather: Frostbite  

MedlinePLUS

... Matters What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... related health problems. More Information: Hypothermia Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

282

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. ...

283

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

Mark Francek

2002-10-01

284

Owlie Skywarn's Weather Book  

NSDL National Science Digital Library

This is an online activity book from the National Weather Service that teaches about hazardous weather. The site also includes links to kids sites for the Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Agency (NOAA).

Cris Garcia

2001-06-22

285

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.

Peter Crane

2004-05-01

286

Fire Weather Climatology  

NSDL National Science Digital Library

The “Fire Weather Climatology” module provides a comprehensive look at fire regions across the United States and characteristics of typical fire seasons in each region. In addition, critical fire weather patterns are described in terms of their development, duration and impact on fire weather. Numerous case studies provide examples and opportunities to practice recognizing these critical patterns and how they can affect fire ignition and spread. This module is part of the Advanced Fire Weather Forecasters Course.

COMET

2008-04-28

287

Enviropedia: Introduction to Weather  

NSDL National Science Digital Library

This resource provides an overview of weather, the day-to-day changes in temperature, air pressure, moisture, wind, cloudiness, rainfall and sunshine. Links embedded in the text provide access to descriptions of cloud types and to information on weather hazards such as fog, hurricanes, thunderstorms, and tornadoes. Other topics include meteorology, weather measurements, and weather mapping. Materials are also provided on the water cycle and its elements, such as evaporation, uplift and cooling of air, dew point, condensation, and precipitation.

2007-12-12

288

Weather and Road Management  

NSDL National Science Digital Library

Anticipating and dealing with weather and the hazards it creates is a real challenge for those in departments of transportation. This module gives road and highway managers a basic understanding of meteorology and weather hazards so that they can better interpret weather forecast information used to make road management decisions. The module also highlights web-based forecast products available from the National Weather Service that can help in the decision-making process.

2014-09-14

289

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

290

Weathering and Erosion  

NSDL National Science Digital Library

This unit provides an introduction for younger students to the concepts of weathering and erosion. Topics include types of weathering (physical versus chemical), rates of weathering, and weathering products (soil). The section on erosion explains the importance of water and gravity in the process, and discusses some of the more important erosional agents such as wind, water and ice, streams and glaciers. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

291

Extreme Weather on Earth  

NSDL National Science Digital Library

In this activity, students utilize a set of photographs and a 30 minute video on weather to investigate extreme weather events. They are posed with a series of questions that ask them to identify conditions predictive of these events, and record them on a worksheet. Climate and weather concepts defined.

Anna Mika

292

METEOROLOGICAL Weather and Forecasting  

E-print Network

AMERICAN METEOROLOGICAL SOCIETY Weather and Forecasting EARLY ONLINE RELEASE This is a preliminary and interpretation of information from National Weather Service watches and warnings by10 decision makers such an outlier to the regional severe weather climatology. An analysis of the synoptic and13 mesoscale

293

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.

Cheryl Dybas

2008-12-07

294

Weather Fundamentals: Meteorology. [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) looks at how meteorologists gather and interpret current weather data collected from sources…

1998

295

Severe Weather Perceptions.  

ERIC Educational Resources Information Center

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

Abrams, Karol

296

Hot Weather Tips  

MedlinePLUS

... Form - 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 ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

297

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.

Charles Burrows

298

Weather Girl Goes Rogue  

NSDL National Science Digital Library

This humorous video suggests what might happen if a weather forecaster reported the weather in the context of climate change. There is a sharp contrast between the anchor focusing on short-term local concerns and the weather forecaster describing what is happening on a long-term global basis.

Deep Rogue Ram

299

American Weather Stories.  

ERIC Educational Resources Information Center

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

Hughes, Patrick

300

Space Weather Now  

NSDL National Science Digital Library

The Space Weather Now page is intended to give the non-technical user a "plain language" look at space weather. It includes information about relevant events and announcements, data from and about different instruments and satellites watching various aspects of space weather, alerts and advisories, daily themes of products and services, and links appropriate for the various groups of users.

Space Environment Center

301

Climate and Weather  

NSDL National Science Digital Library

This video discusses the differences between climate and weather by defining and presenting examples of each. When presenting examples of weather, the video focuses on severe events and how meteorologists predict and study the weather using measurement, satellites, and radar. The climate focus is primarily on an overview of climate zones.

National Geographic

302

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

303

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

304

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

305

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

306

Example of Weathering And Sun Angle  

NASA Technical Reports Server (NTRS)

The letter 'B' or perhaps the figure '8' appears to have been etched into the Mars rock at the left edge of this picture taken yesterday by the Viking 1 Lander. It is believed to be an illusion caused by weathering processes and the angle of the sun as it illuminated the scene for the spacecraft camera. The object at lower left is the housing containing the surface sampler scoop.

1976-01-01

307

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

NASA Astrophysics Data System (ADS)

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

308

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

309

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.

Candice Marshall

2007-01-01

310

Rock Pioneers  

NSDL National Science Digital Library

In this outdoor activity/field trip, learners investigate organisms that live along the ocean's rocky coast. Learners add bare rocks to an intertidal zone, and over the course of 6-8 weeks observe what plant and animals colonize (come to live) on the new rocks. The intertidal zone, covered by water during high tides and uncovered at low tides, is usually densely covered with marine organisms such as seaweeds, mussels, barnacles, snails, limpets, anemones and sea stars. Learners may not only discover pioneer organisms (first colonizers) of their new rocks, but other organisms that replace the first arrivals in the process of succession. This activity calls for multiple, weekly return visits to the intertidal zone.

Lawrence Hall of Science

1981-01-01

311

A Holocene lacustrine rock platform around Storavatnet, Ostery, western  

E-print Network

as formed mainly by frost weathering just outside the Younger Dryas glacier terminus (Marthinussen, 1960; Rasmussen, 1981). Descriptions of lacustrine rock platforms are relatively rare. On the North Island, New Zealand, with an oceanic climate, Allen et al. (2002) interpreted the formation of a lacustrine rock

Fossen, Haakon

312

Ecology and biology of microfungi from Antarctic rocks and soils  

Microsoft Academic Search

Cryptoendolithic microbial communities, living in porous sandstone rocks in the McMurdo Dry Valleys (Ross Desert) of Southern Victoria Land, Antarctica, were found within weathered pegmatite rocks in Northern Victoria Land, and the first endemic Antarctic fungal genus Friedmanniomyces endolithicus anam.?gen. and sp. nov. was isolated from this community. Selected microfungi from these communities and from soil were examined for the

Silvano Onofri; Massimiliano Fenice; Anna Rita Cicalini; Solveig Tosi; Anna Magrino; Sabina Pagano; Laura Selbmann; Laura Zucconi; Helen S. Vishniac; E. Imre Friedmann

2000-01-01

313

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

314

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

315

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.

COMET

2010-09-30

316

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.

317

Erosion and the rocks of Venus  

Microsoft Academic Search

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

CARL SAGAN

1976-01-01

318

Geochemical discrimination of clastic sedimentary rock sources  

Microsoft Academic Search

Factors controlling the geochemistry of a clastic sedimentary rock can include: (1) composition of source terrain, (2) chemical weathering, (3) hydraulic sorting, (4) diagenesis, (5) metamorphism, and (6) hydrothermal alteration. A linear solution inferring source terrain composition from geochemistry of the sediment is impossible in this multivariate system as several unknowns will commonly be present. The use of graphical analysis

P. W. Fralick; B. I. Kronberg

1997-01-01

319

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

320

E-Rock: A Virtual Field Trip  

NSDL National Science Digital Library

This virtual field trip shows students the geologic features of Enchanted Rock, a dome of Precambrian granite located in central Texas. They can see small faults, fault gouge, close-up photos showing the texture of the granite, and a variety of features produced by weathering.

Robert Reed

321

Beyond the Weather Chart: Weathering New Experiences.  

ERIC Educational Resources Information Center

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

Huffman, Amy Bruno

1996-01-01

322

National Weather Service- Severe Weather Awareness  

NSDL National Science Digital Library

This website provides access to information designed to protect and prepare individuals from severe weather. Materials presented here include forecasts for aviation and marine interests and the general public, maps, statistical data, educational materials, publications, and links to related sites.

323

Biogenic rock varnishes of the negev desert (Israel) an ecological study of iron and manganese transformation by cyanobacteria and fungi  

Microsoft Academic Search

The ecology of the microflora, which produces rock varnishes in the Negev is described. It is shown that biogenic rock varnishes may form within relatively short periods (1967–1981) on places where pre-existing varnishes were eliminated. Rock varnishes are thin coatings, mainly composed of Fe and Mn hydroxides and clay material. Biogenic rock varnishes form at places where “microbial weathering fronts”,

W. E. Krumbein; K. Jens

1981-01-01

324

Start a Rock Collection  

NSDL National Science Digital Library

Learners follow a three-step process to start their own rock collection. Learners will collect rocks, record information about each rock on a Rock Chart, observe and sort their rocks, and create a rock display. This activity also includes a book list with resources for rock classification.

2012-06-26

325

Weather: What Forces Affect Our Weather?  

NSDL National Science Digital Library

This website provides an easy-to-understand look at our weather system. Topics covered include the atmosphere, the water cycle, storms, ice and snow, weather forecasting and Earth's changing climate. There are features on ozone depletion, global warming, El Nino and La Nina. An activity allows users to identify cloud formations associated with tornadoes, complete with photographs. There is also a wind chill calculator.

2002-06-11

326

Sedimentary Rocks  

NSDL National Science Digital Library

This is a course handout that accompanies the discussion of the origin of sedimentary rocks. Topics include depositional tectonic settings, texture as an indicator of energy levels in the depositional environment, interpretation of various sandstones, and the influences of paleoclimate and source area lithology. Photos depict grain size and texture. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Pamela Gore

1995-09-24

327

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...

328

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...

329

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...

330

Rock Censorship  

Microsoft Academic Search

This article discusses the issue of censorship of rock music as it pertains to both collectors and directors of libraries interested in popular music collections. It offers both a brief history of recent censorial events, and factual information regarding the censorship issue. It offers suggestions as to what issues those involved need to be familiar with, what the legal issues

James R. McDonald

1994-01-01

331

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).

Steven Strogatz

2010-02-07

332

Igneous Rocks  

NASA Astrophysics Data System (ADS)

“Igneous Rocks was written for undergraduate geology majors who have had a year of college-level chemistry and a course in mineralogy … and for beginning graduate students. Geologists working in industry, government, or academia should find this text useful as a guide to the technical literature up to 1981 and as an overview of topics with which they have not worked but which may have unanticipated pertinence to their own projects.” So starts the preface to this textbook.As one who works part time in research on igneous rocks, especially as they relate to mineral deposits, I have been looking for such a book with this avowed purpose in a field that has a choking richness of evolving terminology and a bewildering volume of interdisciplinary literature. In addition to the standard topics of igneous petrology, the book contains a chapter on the role of igneous activity in the genesis of mineral deposits, its value to geothermal energy, and the potential of igneous rocks as an environment for nuclear waste disposal. These topics are presented rather apologetically in the preface, but the author is to be applauded for including this chapter. The apology shows just how new these interests are to petrology. Recognition is finally coming that, for example, mineral deposits are not “sports of nature,” a view held even by many economic geologists as recently as the early 1960's; instead they are perfectly ordinary geochemical features formed by perfectly ordinary geologic processes. In fact, the mineral deposits and their attendant alteration zones probably have as much to tell us about igneous rocks as the igneous rocks have to tell us about mineral deposits.

Doe, Bruce R.

333

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,

334

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

335

Tales of future weather  

NASA Astrophysics Data System (ADS)

Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like.

Hazeleger, W.; van den Hurk, B. J. J. M.; Min, E.; van Oldenborgh, G. J.; Petersen, A. C.; Stainforth, D. A.; Vasileiadou, E.; Smith, L. A.

2015-02-01

336

Iron isotopic fractionation during continental weathering  

SciTech Connect

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

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01

337

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

NASA Astrophysics Data System (ADS)

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

Gaillardeta, J.; Dupré, B.; Allègre, C. J.

1999-12-01

338

Weather Radar Fundamentals  

NSDL National Science Digital Library

This 2-hour module presents the fundamental principles of Doppler weather radar operation and how to interpret common weather phenomena using radar imagery. This is accomplished via conceptual animations and many interactive radar examples in which the user can practice interpreting both radar reflectivity and radar velocity imagery. Although intended as an accelerated introduction to understanding and using basic Doppler weather radar products, the module can also serve as an excellent refresher for more experienced users.

2014-09-14

339

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

340

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.

Jason Parrish

2007-12-12

341

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 ...

Whitney Frankovic

2009-09-28

342

Cosmic weather and cybernetics  

NASA Astrophysics Data System (ADS)

The use of computer techniques to study cosmic weather (i.e., manifestations of solar activity in near-earth space, the ionosphere, and the lower atmosphere) is examined. A scheme of observational facilities for the acquisition of data on cosmic weather is described; the basic types of observations that yield information on the state of the ionosphere at different altitudes are considered; and the role of computers in the prediction of cosmic weather is assessed.

Avdiushin, Sergei Ivanovich; Danilov, Aleksei Dmitrievich; Dlikman, Fishel'l'vovich

1987-09-01

343

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

344

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.

345

A micromechanics-based elastoplastic damage model for quasi-brittle rocks  

E-print Network

is applied to simulate triaxial compression tests on two sets of diabase samples, the first cored from a fresh diabase rock mass and the second from a slightly weathered one. Comparisons between numerical in the area of Danjiangkou Water Reservoir, such as diabase rock, sandstone, schist rock, etc. Among them

Paris-Sud XI, Université de

346

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

ERIC Educational Resources Information Center

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

Philippines Univ., Quezon City. Science Education Center.

347

Carbonate weathering along a climatic gradient in the Jura Mountains  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

348

Q00906010024 rock check dam  

E-print Network

00906010024 rock check dam Q00906010025 rock check dam Q00906010021 rock check dam Q00906010022 rock check dam Q00906010027 rock check dam Q00906010026 rock check dam Q00906010018 rock check dam Q00906010023 rock check dam Q00906010011 rock check dam Q00906010008 rock check dam Q00906010007 rock check dam Q

349

Meteorology:Meteorology: Weather and ClimateWeather and Climate  

E-print Network

1 Meteorology:Meteorology: Weather and ClimateWeather and Climate Large Scale Weather SystemsLarge--scale Weather Systemsscale Weather Systems Tropical cyclones (1-2) Location, Structure, Life-cycle Formation and modification, airmasses that effect the British Isles Airmasses affecting the British Isles

350

Space Weather: Welcome, SEC  

NSDL National Science Digital Library

This video presentation welcomes the Space Weather Prediction Center, formerly known as the Space Environment Center or 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 SWPC, the NWS now provides environmental understanding from the sun to the sea.

COMET

2005-01-11

351

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 ...

Aubree Miller

2009-09-28

352

Living in the Weather  

NSDL National Science Digital Library

What is weather? Is climate different from weather? It doesn't matter where you live or where you travel, weather patterns influence your daily life. In this guide, students will engage in exploring and predicting the conditions in the atmosphere that are responsible for weather patterns and climatic conditions, and investigate how extreme weather impacts humans and the environment. While many of the keywords embedded into the "Living in the Weather" themes will be familiar, do your students really understand them? This guide provides teacher-tested, reliable links that allow you and your students to "surf" the internet in a quest to better understand how atmospheric conditions directly relate to weather on Earth. Understanding weather and climate can be a great opportunity for you to engage students in topics and themes that connect Earth and space science, life science, and physical science in a real way. The National Science Education Standards (NSES) focus on the study of weather and climate and their impact on human life. This guide uses the ongoing work and technology of the National Oceanic and Atmospheric Administration (known to the public simply as NOAA). NOAA scientists study our planet Earth in a global way. Working together with scientists worldwide, NOAA scientists study the diversity of living organisms (including humans) and their impact on our environment--not only in our country but in every country and continent around the world.

National Science Teachers Association (NSTA)

2006-12-13

353

Cockpit weather information needs  

NASA Technical Reports Server (NTRS)

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

Scanlon, Charles H.

1992-01-01

354

Pilot Weather Advisor System  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

355

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.

356

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

357

Terby's Rocks  

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

358

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

359

Poohbear Rock  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

360

Rock Cycle Animation  

NSDL National Science Digital Library

Use this interactive rock cycle animation to help you with your schoolwork! 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.

2010-01-01

361

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

362

Weathering of sulfides on Mars  

NASA Astrophysics Data System (ADS)

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.

363

External Resource: Rock and Roll  

NSDL National Science Digital Library

This page contains information on exactly what a rock is, as well as a diagram of the rock cycle. Topics include: characteristics of rocks, types of rocks, igneous rocks, metamorphic rocks, and sedimentary rocks.

1900-01-01

364

Welcome to Rock Day  

NSDL National Science Digital Library

Seeking to revitalize a unit on rocks, sand, and soil for first-graders, the authors created new hands-on lessons. These included testing the hardness of rocks, making models of the Earth, and sorting rocks. As a culminating activity, students participated in a series of Rock Day events that focused on the three different types of rocks and the rock cycle.

Jeaneen Benhart

2004-01-01

365

Weather and emotional state  

NASA Astrophysics Data System (ADS)

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

Spasova, Z.

2010-09-01

366

Sliding Rocks on Racetrack Playa, Death Valley National Park: First Observation of Rocks in Motion  

PubMed Central

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

Lorenz, Ralph D.; Ray, Jib; Jackson, Brian

2014-01-01

367

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

PubMed

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

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

2014-01-01

368

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

369

Exercising in Cold Weather  

MedlinePLUS

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

370

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

371

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

372

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.

Sue Palewicz

373

World weather program  

NASA Technical Reports Server (NTRS)

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

1980-01-01

374

The Home Weather Station.  

ERIC Educational Resources Information Center

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

Steinke, Steven D.

1991-01-01

375

Designing a Weather Station  

ERIC Educational Resources Information Center

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

Roman, Harry T.

2012-01-01

376

Winter Storms Weather Quizzes  

E-print Network

Quizzes pg 3 pg 22 pg 7 pg 29 pg 13 pg 17 #12;Weather can be calm and peaceful. It also can be violent and the news media. We will tell you what is happening. Stay tuned! Hurricane Warning When the National Weather

377

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

378

Next Generation Weather Lab  

NSDL National Science Digital Library

Users can learn about weather data output and analysis at the Next Generation Weather Lab website. This expansive website provides an abundance of surface data and upper air data as well as satellite and radar images for the United States. Types of data include plotting maps, contoured images, soundings, and cross sections.

379

Weather Data Gamification  

E-print Network

of the weather patterns and climate change trends for those cities. We do a user-study to evaluate our application and prove its feasibility. An evaluation of the fantasy weather game indicates that the game had the desired effect of causing players to explore...

Gargate, Rohit

2013-07-25

380

Weather and Culture.  

ERIC Educational Resources Information Center

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

Contemporary Learning Center, Houston, TX.

381

Weather Theory Introduction  

E-print Network

protects life on Earth from high energy radiation and the frigid vacuum of space. Composition a Flight Service Station (FSS) weather specialist and other aviation weather services. Be it a local flight, and waves that travel for great distances. Life on Earth is supported by the atmosphere, solar energy

382

Weather Fundamentals: Clouds. [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) discusses how clouds form, the different types of clouds, and the important role they play in…

1998

383

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

384

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.

Watsonville Environmental Science Workshop

2011-01-01

385

Teacher's Weather Sourcebook.  

ERIC Educational Resources Information Center

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

Konvicka, Tom

386

Tracking Weather Satellites.  

ERIC Educational Resources Information Center

Describes the use of weather satellites in providing an exciting, cohesive framework for students learning Earth and space science and in providing a hands-on approach to technology in the classroom. Discusses the history of weather satellites and classroom satellite tracking. (JRH)

Martin, Helen E.

1996-01-01

387

EMERGENCY, DISASTER, & WEATHER INFORMATION  

E-print Network

EMERGENCY, DISASTER, & WEATHER INFORMATION University · Campus Emergency and Inclement Weather.umaryland.edu/health · Dental Care: 6-7102 or 6-7063 www.dental.umaryland.edu/ patientinfo · Student Counseling Center: 8.parking.umaryland.edu Police and Public Safety 6-6882, 711 (emergency) www.umaryland.edu/police Recreation and Fitness 6-PLAY

Weber, David J.

388

What Is Space Weather?  

NSDL National Science Digital Library

This resource provides a brief overview of the phenomenon known as space weather, which happens when energetic particles emitted by the Sun impact the Earth's magnetosphere. Users can view images, video clips, and animations of auroras and other types of space weather. A set of links to related websites is also provided.

389

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

390

Geochemistry and origin of ferruginous nodules in weathered granodioritic gneisses, Mysore Plateau, Southern India  

Microsoft Academic Search

Fe-nodules occur within saprolites formed from weathering of granodioritic gneisses in the rain-shadow region of the Mysore Plateau adjacent to the Sahyadri Mountains in Southern India. These nodules and their host saprolites were studied for their geochemistry, including chemical speciation, to understand nodule formation and chemical redistribution processes during rock weathering. From their mode of occurrence, and mineralogical and geochemical

Jayant K. Tripathi; V. Rajamani

2007-01-01

391

Reconnaissance of Field Sites for the Study of Chemical Weathering on the Guayana Shield, South America  

Microsoft Academic Search

Despite the fact that chemical weathering of silicate rocks plays an important role in the draw-down of COâ over geologic time scales (Berner and Berner, 1996), the overall controls on the rate of chemical weathering are still not completely understood. Lacking a mechanistic understanding of these controls, it remains difficult to evaluate a hypothesis such as that presented by Raymo

Steefell

2003-01-01

392

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.

393

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

394

Weathering of the Rio Blanco quartz diorite, Luquillo Mountains, Puerto Rico: Coupling oxidation, dissolution, and fracturing  

Microsoft Academic Search

In the mountainous Rio Icacos watershed in northeastern Puerto Rico, quartz diorite bedrock weathers spheroidally, producing a 0.2–2m thick zone of partially weathered rock layers (?2.5cm thickness each) called rindlets, which form concentric layers around corestones. Spheroidal fracturing has been modeled to occur when a weathering reaction with a positive ?V of reaction builds up elastic strain energy. The rates

Heather L. Buss; Peter B. Sak; Samuel M. Webb; Susan L. Brantley

2008-01-01

395

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 ...

Laura Heffernan

2010-06-21

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

Edible Rocks  

NSDL National Science Digital Library

This lesson has been designed as a comfortable introduction to describing meteorites. It helps students become better observers by making a connection between the familiar (candy bars) and the unfamiliar (meteorites). Edible "rocks" are used in a scientific context, showing students the importance of observation, teamwork and communication skills. In everyday terms, students draw and describe the food. They pair their observations with short descriptions that are in geologic "Field Note" style. As the teacher and class review, appropriate geologic terminology may be substituted by the teacher and subsequently embraced by even very young students.

Marilyn Lindstrom

399

Frost weathering: Climate control of regolith production and critical zone evolution  

NASA Astrophysics Data System (ADS)

Rock generally displays greater fracture density and reduced strength near the surface than at depth. Relatively few processes can explain this profile of mechanical damage seen in rock. Motivated by weathered rock profiles measured in Gordon Gulch in the Boulder Creek Critical Zone Observatory (Colorado Front Range, USA), we focus on frost cracking as an important weathering process. We use our measurements to guide a model of frost cracking. Although the modern mean annual ground temperature is ~4°C, it was subzero during Pleistocene glacial times. Frost cracking is therefore a plausible mechanism of rock damage. Rock on north-facing slopes in this high elevation catchment (~2600 m a.s.l.) is more deeply weathered and displays lower tensile strength than rock on south-facing slopes. We present detailed subsurface temperature profile records at sites on both slopes, reaching depths up to 1.5 m, and therefore crossing the mobile regolith - saprolite interface. We augment existing frost cracking models by incorporating daily thermal cycles, snow cover, latent heat, variation in material properties with depth, and limitations imposed by long transport distances for water to the freezing front. The north- and south-facing hillslope asymmetries in critical zone architecture can be explained with differences in mean annual surface temperatures, although moisture differences may also play a role. A temperature-controlled model of rock weathering enables consideration of the effect of climate change on weathered profile development.

Anderson, S. P.; Anderson, R. S.; Kelly, P. J.; Tucker, G. E.; Wickert, A.

2012-04-01

400

Food Safety for Warmer Weather  

MedlinePLUS

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

401

Environmental Education Tips: Weather Activities.  

ERIC Educational Resources Information Center

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

Brainard, Audrey H.

1989-01-01

402

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 ...

403

A model of weathering intensity for the Australian continent  

NASA Astrophysics Data System (ADS)

Regolith encompasses all weathered materials in the zone between the Earth's surface and fresh bedrock at depth. This weathered zone includes the soil, which may constitute the whole of the regolith profile or represent only its upper part. Important hydrological and biogeochemical processes operate within the regolith, including the infiltration and storage of near-surface water and nutrients, which sustain agricultural productivity. The degree to which the regolith is weathered (or its weathering intensity) is intrinsically linked to the factors involved in soil formation including parent material, climate, topography, biota and time. The degree to which the bedrock or sediments are weathered has a significant effect on the nature and distribution of regolith materials. There is commonly a strong correlation between weathering intensity and the degree of soil development as well as the depth of the weathering front. Changes in weathering intensity correspond to changes in the geochemical and physical properties of bedrock, ranging from essentially unweathered parent materials through to intensely weathered and leached regolith where all traits of the original protolith (original unweathered rock) are overprinted or lost altogether. With increasing weathering intensity we see mineral and geochemical convergence to more resistant secondary weathered materials including clay, silica, and various oxides. A weathering intensity index (WII) over the Australian continent has been developed at a 100 m resolution using two regression models based on airborne gamma-ray spectrometry imagery and the Shuttle Radar Topography Mission (SRTM) elevation data. Airborne gamma-ray spectrometry measures the concentration of three radioelements -- potassium (K), thorium (Th) and uranium (U) at the Earth's surface. The total gamma-ray flux (dose) is also calculated based on the weighted additions of the three radioelements. In general K is leached with increasing weathering whereas Th and U typically show increases due to their association in clays and oxides in the profile. These geochemical relationships underpin the first model prediction. In the case where no gamma-ray data is available or where the bedrock is very low in radioelements (e.g. basalt, quartz-rich sandstone) surface relief is used as surrogate in the second prediction model. The two models are combined to generate a weathering intensity index of the Australian continent. The weathering intensity index has been developed for erosional landscapes but also provides useful information on deposition processes and materials. The weathering intensity prediction is evaluated with surface geochemistry (compared with geochemical indices) and previous regolith-landform mapping. The use of the weathering intensity index in natural resource management and mineral exploration is discussed.

Wilford, J.

2013-12-01

404

Fire Weather Forecasting: Clear Communications  

NSDL National Science Digital Library

The “Fire Weather Forecasting: Clear Communications” distance learning module offers best practices for Fire Weather Forecasters needing to communicate weather information when deployed in the field. The 30-minute module defines strategies for communicating with Weather Forecast Offices and with customers. Examples include writing a useful fire weather forecast discussion and undertaking proper planning to quickly and accurately disseminate information. This distance learning module is part of the Advanced Fire Weather Forecasters Course.

2014-09-14

405

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

406

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

407

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

408

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

409

Weather Observing Fundamentals  

NSDL National Science Digital Library

"Weather Observing Fundamentals" provides guidance for U.S. Navy Aerographer's Mates, Quartermasters, and civilian observers tasked with taking and reporting routine, special, and synoptic observations. Although the focus of this lesson is on shipboard observations, much of the content applies to land-based observing and reporting as well. The lesson details standard procedures for taking accurate weather observations and for encoding those observations on COMNAVMETOCCOM Report 3141/3. Exercises throughout the lesson and four weather identification drills at the end provide learners with opportunities to practice and build their skills. The lesson covers a large amount of content. You may wish to work through the material in multiple sessions.

2014-09-14

410

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

411

Weather and Climate  

NSDL National Science Digital Library

This unit introduces younger students to the concepts of weather and climate. Topics include the structure of the atmosphere, the definitions of weather and climate, and temperature and how it is measured. There are also discussions of heat transfers (radiation, conduction, convection), air pressure, wind, and the Coriolis effect. Other topics include types of storms, larger-scale weather systems such as pressure systems and fronts, and factors (insolation, land-sea breezes, orographic effect) that influence the climate in a given region. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

412

Space Weather Now  

NSDL National Science Digital Library

The NOAA Space Weather Now website provides non-technical information and an assortment of images detailing current space weather. Visitors can find summaries describing auroras, plots of current auroral ovals on the poles, and viewing information for the Northern and Southern Hemispheres. The Real-Time Solar Wind Pages furnish dynamic plots of data, geomagnetic activity test product information, and resources about the four instruments used to collect data on geomagnetic storms. The website features Space Weather Scales to help the public understand the severity of environmental disturbances due to geomagnetic storms, solar radiation storms, and radio blackouts. Visitors can find the latest news, alerts, advisory bulletins, and much more.

413

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.

414

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.

415

WeatherTracker  

NSDL National Science Digital Library

WeatherTracker is the ideal desktop application for anyone who always wants to know what the weather outside is like. The temperature, barometric pressure, humidity, winds, and current conditions can be displayed in three different formats, updated hourly for North American Cities. The local forecasts, climate data and near shore marine forecasts can be displayed in other windows and are available for select North American cities. Other cities are limited to temperature and current conditions. WeatherTracker is shareware with a fee of $20.00.

416

Microbial Weathering of Peridotites by a Tropical Cyanobacterial Mat  

NASA Astrophysics Data System (ADS)

Nickeliferous tropical laterites represent more than 60 percent of the worlds Ni reserves and are believed to be the product of millions of years of weathering on ultramafic peridotite rocks in tropical regions. While both Cyanobacterial mats and microbial weathering processes are well characterized in general, these structures have never been implicated in ultramafic rock weathering. We used Au/Hg amalgam voltammetric microelectrodes to measure several important dissolved redox-active species (Fe (II), Mn (II), oxygen, peroxide, and organo-Fe/Mn complexes) in situ. Dissolved Fe II/III, phosphate, nitrite, nitrate and electrical conductivity, pH, & Eh were measured on site by spectrophotometry and combination electrodes, respectively. Mat, rock and water samples were compared using a suite of analytical techniques (XRD, SIMS, XPS, ICP-MS). Microbial community structure was determined using ESEM and 16S rDNA cloning. In order to further investigate the relative importance of peroxide and organic ligands (e.g. DFAM) on weathering, laboratory incubations, monitored by voltammetry, were also conducted. In situ voltammetric profiles revealed significant redox zonation and the presence of both organo-Mn (III/IV) and organo-Fe(III) complexes within the mat. Importantly, 50 ?M peroxide was detected within 15 mm of the atmosphere/mat interface. The mat was highly enriched in Ni and Mn compared to the substrate. XPS and dynamic SIMS characterization of the rock surface showed trace metal zonation within a weathering rind. Laboratory experiments demonstrated maximal dissolution of Ni and Mn from the substrate in the presence of both peroxide and DFAM. The high peroxide concentrations in the mat are likely produced via a photochemical reaction involving DOC. Microbial successions resulting in the accumulation of organic material allow the development of redox zonation. We propose a mechanism for enhanced weathering of serpentenized peridotites under microaerophilic conditions, by means of a combination of peroxide and bacterially produced organic ligands. This process may be important for the development of nickeliferous laterite deposits.

Fowle, D.; Crowe, S.; O'Neill, A.; Weisener, C.

2006-12-01

417

Space Weathering: A Lesson from Itokawa  

NASA Astrophysics Data System (ADS)

Reflectance spectra of S-type asteroids are different from those of ordinary chondrites There are also spectral differences between lunar rocks and soils of the similar composition These spectral mismatches are explained by the so-called space weathering S-type asteroids exhibit more overall depletion and reddening of spectra and more weakening of absorption bands relative to ordinary chondrites Formation of nanophase metallic iron particles due to high velocity dust impacts as well as sputtering by solar wind would be responsible for the spectral change We succeeded in reproducing the spectral change expected in space weathering using nano-second pulse laser irradiation on silicates simulating high-velocity dust impacts We confirmed the formation of nanophase iron particles using TEM Sasaki S et al 2001 Nature 410 555-557 We considered regolith-like surface condition is essential for space weathering since evaporated materials may condense with nano-iron particles on the surfaces of other particles The size-dependent transition from Q-type ordinary chondrite-like objects to S-type objects also suggested that regolith is scarce abundant on objects smaller larger than the transition size Binzel R P et al 2004 Icarus 170 259-294 In 2005 Hayabusa spacecraft rendezvoused an S-type asteroid 25143 Itokawa with size of 550m and performed a color imaging by onboard camera AMICA Approximately 80 of Itokawa s surface is rough and boulder-rich but it has a somewhat weathered

Sasaki, S.; Hiroi, T.; Nimura, T.

418

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.

419

Rock Climbing Scholarship Winners  

E-print Network

Highlights · Rock Climbing · TOEFL® · Scholarship Winners · Exit Test TheELIWeekly Rock Climbing An afternoon of extreme fun! On Saturday, July 25th, join us to spend the afternoon rock climbing! What: Come Rock Climb at the Gainesville Rock Gym. No experience necessary. Everyone is welcome! What to Wear

Pilyugin, Sergei S.

420

Rocks and Minerals  

NSDL National Science Digital Library

This guide provides introductory information about rocks and minerals. Topics include some of the common rock-forming minerals, what rocks are made of, and where they come from (the three basic rock types). There are descriptions and photos of igneous, sedimentary, and metamorphic rocks, a glossary, and a simple identification chart that has links to websites with additional information.

421

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

422

Sojourner Rover View of Souffle Rock  

NASA Technical Reports Server (NTRS)

Sojourner's observations in the Ares region on Mars raise and answer questions about the origins of the rocks and other deposits found there. This image shows the vesicular and pitted textures of Souffle Rock (32 cm wide) which could be a result of volcanic, sedimentary, or weathering processes.

NOTE: original caption as published in Science Magazine

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

1997-01-01

423

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 ...

424

How does weather change?  

NSDL National Science Digital Library

This activity is a field investigation where students gather temperature and weather data in the a.m and p.m. and develop a new, experimental question to predict temperature over the course of the year.

Susan Anderson, Taylors Falls Elementary, Taylors Falls, MN based on an activity from Houghton Mifflin Science Grade 2 Weather Patterns, p. D6.

425

Waste glass weathering  

SciTech Connect

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

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

1993-12-31

426

The Weather Calculator  

NSDL National Science Digital Library

This set of conversion tools helps convert units and values for weather data, including temperature, moisture, atmospheric pressure, wind, and other parameters. Formulas are also provided for the conversions.

427

Predicting Seasonal Weather  

NSDL National Science Digital Library

Large-scale weather patterns which occur in various locations around the Earth play a significant part in controlling the weather on a seasonal time scale. A National Science Foundation (NSF)-funded collaborative research effort between Atmospheric and Environmental Research, Inc. (AER), and the Massachusetts Institute of Technology (MIT) has led to a new understanding of the relationship between fall snow cover and winter climate variability. This research has led to the development of a new seasonal forecast model.

428

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

429

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)

430

Weathering and Erosion  

NSDL National Science Digital Library

In this multi-station lab, learners conduct a series of experiments to explore the processes and effects of weathering and erosion. Using the results from these explorations, learners design and conduct an experiment comparing the rate of erosion in different biomes. Use this activity to teach weathering and erosion, and also to illustrate how scientists often use the results of one experiment to inspire another. This activity is intended to be conducted over multiple meetings.

Lise Whitfield

2010-01-01

431

Cockpit weather information system  

NASA Technical Reports Server (NTRS)

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

Tu, Jeffrey Chen-Yu (Inventor)

2000-01-01

432

Utility weatherization programs  

SciTech Connect

Public utility commissions (PUCs) have recently ordered or approved an increasing number of programs that install weatherization measures in residences. These programs tend to install only low-cost weatherization measures (e.g., caulking, weatherstripping, plastic storm windows, door sweeps) or major weatherization measures (e.g., insulation, storm windows, storm doors). When a program does not have income restrictions for eligibility, part of the costs are paid by the participating customer. For programs that install low-cost measures, the participant usually pays at the time of installation for the measures chosen. To require payment for major weatherization measures at the time of installation could deter participation, so these programs usually provide loans with the interest subsidized by the sponsor. Low-income customers, who have little or no disposable income, tend to shun Residential Conservation Service, loan, and other utility conservation programs that have costs to participants. Therefore PUCs have turned to programs that install weatherization measures without charge in order to reach low-income customers. This paper discusses some of the regulatory issues raised by these programs and how they have been justified by PUCs. It also gives information on cost and energy savings for 10 weatherization programs, both utility-sponsored and non-utility-sponsored, and attempts to interpret this information.

Kier, P.H.

1984-01-01

433

In situ fragmentation and rock particle sorting on arid hills  

NASA Astrophysics Data System (ADS)

Transport processes are often proposed to explain the sorting of rock particles on arid hillslopes, where mean rock particle size often decreases in the downslope direction. Here we show that in situ fragmentation of rock particles can also produce similar patterns. A total of 93,414 rock particles were digitized from 880 photographs of the surface of three mesa hills in the Great Sandy Desert, Australia. Rock particles were characterized by the projected Feret's diameter and circularity. Distance from the duricrust cap was found to be a more robust explanatory variable for diameter than the local hillslope gradient. Mean diameter decreased exponentially downslope, while the fractional area covered by rock particles decreased linearly. Rock particle diameters were distributed lognormally, with both the location and scale parameters decreasing approximately linearly downslope. Rock particle circularity distributions showed little change; only a slight shift in the mode to more circular particles was noted to occur downslope. A dynamic fragmentation model was used to assess whether in situ weathering alone could reproduce the observed downslope fining of diameters. Modeled and observed size distributions agreed well and both displayed a preferential loss of relatively large rock particles and an apparent approach to a terminal size distribution of the rocks downslope. We show this is consistent with a size effect in material strength, where large rocks are more susceptible to fatigue failure under stress than smaller rocks. In situ fragmentation therefore produces qualitatively similar patterns to those that would be expected to arise from selective transport.

McGrath, Gavan S.; Nie, Zhengyao; Dyskin, Arcady; Byrd, Tia; Jenner, Rowan; Holbeche, Georgina; Hinz, Christoph

2013-03-01

434

The Influence of Weathering on the Engineering Properties of Dunites  

NASA Astrophysics Data System (ADS)

Weathering processes cause important changes in the engineering properties of rocks. In this study, dunites in the Bursa region in western Turkey were investigated and the changes in engineering properties due to weathering were evaluated. The studies were initiated with field observations including measurement of the characteristics of discontinuities such as spacing, aperture, fill material, roughness, and Schmidt hammer rebound value. Subsequently, laboratory studies were conducted in two stages. The first stage comprised mineralogical, petrographic, and chemical analyses. The second stage included physicomechanical tests to determine specific gravity, unit weights, water absorption, effective porosity, uniaxial compressive strength, P-wave velocity, and slake-durability index. According to these evaluations, the changes in engineering properties were determined to be mostly related to serpentinization at every stage of weathering. The most suitable parameters for characterizing the degree of weathering of the studied dunites are loss-on-ignition values, specific gravity, unit weight, water absorption, and effective porosity.

Ündül, Ömer; Tu?rul, Atiye

2012-03-01

435

S-290 Unit 9: Observing the Weather  

NSDL National Science Digital Library

This webcast covers procedures for taking accurate weather observations using belt weather kits and descriptions of other common weather observing equipment used in fire weather. In addition, maintenance of the primary components of the belt weather kit are demonstrated.

2014-09-14

436

2012 Severe Weather Awareness Guide  

E-print Network

Florida's 2012 Severe Weather Awareness Guide 2012 Severe Weather Awareness Guide F L O R I D A D I of Emergency Management #12;Florida's Severe Weather Awareness Guide 2 Florida is affected by many natural. That is why I am proud to present the 2012 Severe Weather Awareness Guide. By reading this guide you can learn

Meyers, Steven D.

437

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

438

The poisonous rocks of Kärkevagge  

NASA Astrophysics Data System (ADS)

The black schist in Kärkevagge, Swedish Lapland has been reported to weather easily and produce a poisonous effect on vegetation. This research was an investigation of that phenomenon as part of a larger study of weathering in Kärkevagge. In July 1999, soil and plant samples were collected downslope of a "poisonous" boulder. Samples from the adjacent unaffected slope served as references. Biomass, plant elemental composition, and soil fertility were determined. Most plants within 1.4 m downslope of the poison boulder were dead, and effects on plant growth could be seen to about 6 m. Plants near the boulder had elevated levels of K, B, Al, Cd, Se, and Fe, and lower levels of Ca, Mn, and Ba compared to reference plants. In the soil near the poison boulder, extractable S, Cd, and Fe and salt contents were greater, while pH and extractable Cl, P, Ca, Mg, K, Ba, Ni, and Cr were lower than in the reference soil. At 10 m downslope of the boulder, soil and plant chemistry was more similar to the reference materials, but some effects were still noted. Elemental analyses of the poison boulder and soil revealed no particular plant toxins, although contents of Fe and S were higher and Ca lower than in reference materials. We believe the poison is sulfuric acid, which forms as a consequence of pyrite oxidation. The dark color of the boulder is consistent with a pyrite-bearing lithology and other field observations and laboratory analyses support the hypothesis. Coatings on local rocks include jarosite, gypsum, and copiapite, secondary minerals associated with pyrite oxidation and weathering accelerated by sulfuric acid. Radiocarbon dating indicates that the rock fell off the cliff some time before 245 14C years BP.

Darmody, R. G.; Allen, C. E.; Thorn, C. E.; Dixon, J. C.

2001-11-01

439

Major Rock Groups  

NSDL National Science Digital Library

This resource from the University of Saskatchewan contains general information on the major rock groups: igneous, metamorphic and sedimentary. Describes the rock cycle and the properties and formation of each major rock group.

440

Texas Rock Cycle  

NSDL National Science Digital Library

The Texas Rock Cycle is an exercise demonstrating rock transformation. Materials needed for this activity are the Texas Rock Kit and a page-size Geologic Map of Texas, each available from the publications department of the Bureau of Economic Geology. Each rock kit contains samples of calcite, quartz, feldspar, granite, basalt, sandstone, gneiss, limestone, chert, and schist. This site contains a rock cycle puzzle to print out and instructions on how to conduct a rock cycle investigation.

441

Collecting and Identifying Rocks  

NSDL National Science Digital Library

In this Earth Science activity, students will investigate rocks in an outdoor field trip. Students will be divided into groups and given a Ziploc bag to collect rocks. We will then return to the classroom, and the students will put their rocks into different groups. The different groups could be the size, shape, color, and texture of the rocks. We will then talk about the Rock Cycle and the three main types of rocks. Students will record their observations in their science journals.

Linda Harvey, Marquette Catholic School, Virginia,MN

442

All About Rocks  

NSDL National Science Digital Library

Rocks are the most common material on earth. We will learn about the 3 main types of rocks and how they are made. Let's do a little warm up... 1.What do you already know about rocks? 2.Where have you seen rocks before? 3.Name all the ways you can think of that people use rocks, and what they use them for... 4.Do you know how rocks are formed? 5.What do you think the world would be like without any ...

Aubree Miller

2009-12-14

443

Alteration of Lunar Rock Surfaces through Interaction with the Space Environment  

NASA Technical Reports Server (NTRS)

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

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

2014-01-01

444

Rocks are fun  

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. Click on each of the links below to learn about the main types of rocks and then answer the questions that follow. *Igneous Rocks 1. In your own words, explain the TWO ways in which an igneous rock can be formed. 2. Please illustrate ONE of the ways an igneous rock is formed. *Metamorphic Rocks 1. Why ...

Lori Peterson

2009-12-14

445

Rock Cycle Roundabout  

NSDL National Science Digital Library

In this activity, learners will learn how igneous rock, metamorphic rock, and sedimentary rock are formed as part of the rock cycle and that the same forces that produce/change rocks also produce/change landforms. They will learn this by playing a game where one player must describe a type of rock (that is chosen by random card selection) to another player who then must guess what type of rock that is. Then, there may be a discussion of geologic time and learners can create a timeline model based on the sequence of rock types that were chosen in the game.

California Academy of Sciences

2010-01-01

446

Weather and The Water Cycle  

NSDL National Science Digital Library

Students will be able to do activities dealing with weather and water cycles. Learn what makes weather wet and wild, forcast and predict weather. Webweather For Kids Learn about tornadoes and hurricanes. Kidstorm Learn about the water cycles. water Cycles Now click on the following link: Interactive weather maker 1. How much change in temperature is needed to make it snow? On the right side of the page click on Weather Detective Web Quest. Follow the ...

Mrs. Merritt

2005-10-15

447

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

448

Spirit Discovers New Class of Igneous Rocks  

NASA Technical Reports Server (NTRS)

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

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

The Gusev rocks define a new chemical category not previously seen on Mars, as shown in this diagram plotting alkalis versus silica, compiled by University of Tennessee geologist Harry McSween. The abbreviations 'Na2O' and 'K2O' refer to oxides of sodium and potassium. The abbreviation 'SiO2' refers to silica. The abbreviation 'wt. %' indicates that the numbers tell what percentage of the total weight of each rock is silica (on the horizontal scale) and what percentage is oxides of sodium and potassium (on the vertical scale). The thin lines separate volcanic rock types identified on Earth by different scientific names such as foidite and picrobasalt. Various classes of Gusev rocks (see box in upper right) all plot either on or to the left of the green lines, which define 'alkaline' and 'subalkaline' categories (subalkaline rocks have more silica than alkaline rocks).

Members of the rover team have named different classes of rocks after specimens examined by Spirit that represent their overall character. During the rover's travels, Spirit discovered that Adirondack-class rocks littered the Gusev plains; that Backstay, Irvine, and Wishstone-class rocks occurred as loose blocks on the northwest slope of 'Husband Hill'; and that outcrops of Algonquin-class rocks protruded in several places on the southeast face.

These rocks have less silica than all previously analyzed Mars samples, which are subalkaline. The previously analyzed Mars samples include Martian meteorites found on Earth and rocks analyzed by the Mars Pathfinder rover in 1997. Gusev is the first documented example of an alkaline igneous province on Mars.

2006-01-01

449

Rare earth elements in weathering profiles and sediments of Minnesota: Implications for provenance studies  

USGS Publications Warehouse

The relative abundance of rare earth elements in sediments has been suggested as a tool for determining their source rocks. This correlation requires that weathering, erosion, and sedimentation do not alter the REE abundances, or do so in a predictable manner. We find that the rare earth elements are mobilized and fractionated by weathering, and that sediments derived from the weathered materials can display modifications of the original pattern of rare earth elements of some due to grain-size sorting of the weathered material. However, the REE distribution pattern of the provenance terrane can be recognized in the sediments.

Morey, G.B.; Setterholm, D.R.

1997-01-01

450

All About Rocks  

NSDL National Science Digital Library

What does igneous mean? What is a sedimentary rock? You have been given the challenge to learn all you can about rocks and minerals. Use the following sites to collect information. You will be compiling the information you learn into a book for the other classes. These two sites will give you information about how rocks are formed. Make sure you find out the 3 types of rocks! Discover How Rocks Are Formed Rocks for Kids What is the difference between a rock and a mineral? See if you can figure it out on these two sites. This planet really rocks! : all about rocks and minerals Rocks for Kids Test your knowledge about rocks with a ...

Miss Quinn

2005-06-16

451

Interactive Rock Cycle Animation  

NSDL National Science Digital Library

This highly simplified Flash animation displays some of the most common rock-forming processes. Embedded animations include crystallization of magma to form igneous rock, rock erosion to create sediment, transportation of sediment, deposition of sediment to create sedimentary rock, and creation of a metamorphic rock in a subduction zone. The neat feature of this animation is that each step in the sequence above is linked to other animations in the Exploring Earth collection, providing a fairly in depth exposure to the processes involved in the rock cycle. Caution students against the oversimplified linear pattern of igneous, sedimentary, and metamorphic rock formation. In reality, there are many interconnections in the cycle with, for example, sedimentary rocks being eroded and becoming transformed to a different sedimentary rock type without being metamorphosed or, as another example, igneous rocks never being reduced to sediment, and instead directly evolving to metamorphic rocks. The animation can be paused and rewound to stress important points.

Lenni Armstrong

452

Chemical Composition of Martian Rocks  

NASA Astrophysics Data System (ADS)

In situ analyses of martian surface rocks (and soils) provided data about the chemical composition of several landing sites. One of the used techniques is the alpha-induced x-ray emission applied by the Alpha Particle X-Ray Spectrometer (APXS) onboard the current Mars Exploration Rovers (MER) Spirit and Opportunity and onboard the preceding Mars Pathfinder Rover Sojourner (MPF Mission). These measurements encompass the determination of major, minor, and (for the MER APXS) trace elements, such as Ni, Zn, and Br, as well as Cu, Pb, Sr, Y, Ga, and Ge. The obtained data indicate a remarkable compositional difference between the rocks at the different landing sites, whereas most soils including those measured by the Viking landers are chemically similar. Initially, the only chemical data of Mars were obtained by the study of a class of meteorites that turned out to be martian, which was furthermore confirmed by the discovery of a rock (by rover Opportunity) that is chemically related to those meteorites. The rocks at the Pathfinder landing site turned out to be richer in Si and K than the martian meteorites and all rocks encountered at the MER sites. At Gusev crater (the first MER landing site), two geological regions were encountered along the rover Spirit's traverse: the plains and the hills. Rocks in the plains resemble primitive basalts, while rocks located in the Columbia Hills revealed different types. Several rock classes could be cataloged based on their chemical composition. Most of the hills rocks are significantly weathered and enriched in mobile elements, such as P, Zn, S, Cl, and Br. On the other hand, a suite of ultramafic rocks was discovered for the first time on Mars. The rocks at Meridiani Planum (the second MER landing site) are salt-rich siliciclastic sediments. All rocks showed much higher S contents than the soils. High concentrations of Cl and Br were also discovered at various samples. Huge quantities of spherules were found on top of soils and outcrops along the rover's traverse. APXS measurements revealed that these spherules contain high amounts of iron that is mainly present as the mineral hematite (determined by Mössbauer spectrometry). The formation of hematite is typically, but not exclusively, an indicator for aqueous activities under oxidizing conditions. The in situ measurements at both MER landing sites point to a variety of sedimentary processes and various types of alteration processes; hence, they show clear evidence of ancient aqueous environments that discontinued long time, ago. The combination of in situ measurements and element correlations obtained by the martian meteorites implies an ancient basaltic crust with high abundances of incompatible elements (K, Rb, Nd, U, and Th) and volatile elements (S, Cl). Compared to the Earth's mantle, the martian mantle contains about twice as much Fe, is richer in moderately volatile elements like K, and has a much higher abundance of phosphorus. In conjunction with chemical data obtained from orbit, such as gamma-ray spectrometry carried out by the Mars Odyssey spacecraft, a global estimation of the composition of the martian surface is obtained and, furthermore, crustal composition can be derived.

Brueckner, J.

2007-05-01

453

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.

Kimberly Lightle

454

Weather from the Stratosphere?  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

455

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.

Kimberly Lightle

2006-01-01

456

Initial effects of vegetation on Hawaiian basalt weathering rates  

SciTech Connect

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

Cochran, M.F.; Berner, R.A. (Yale Univ., New Haven, CT (United States))

1992-01-01

457

A Photographic Atlas of Rock Breakdown Features in Geomorphic Environments  

NSDL National Science Digital Library

This downloadable (15 mb) atlas features photos of rocks, rock formations, and landscapes that have been shaped by aeolian (wind), fluvial (river), and other weathering processes. The photos are accompanied by descriptions of the features and discussion of the processes involved in creating them. There is also a discussion of the applicability of these same processes to explain similar features seen on Mars and Venus, and the use of high-resolution imagery from Mars to identify these features. A bibliography is included.

458

Fungal attack on rock: solubilization and altered infrared spectra.  

PubMed

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

Silverman, M P; Munoz, E F

1970-09-01

459

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.

2007-12-12

460

Chemical weathering of granite under acid rainfall environment, Korea  

NASA Astrophysics Data System (ADS)

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

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

2008-08-01

461

Space weather center  

NSDL National Science Digital Library

Five tutorials about space weather topics make up this web site. Plasma, the sun, Earth's magnetic field, magnetic storms, and the research and modeling of space weather are the topics, respectively, of the five tutorials. The tutorials use numerous enlargeable graphics, some animations and games, and additional special features like sound recordings of space weather phenomena to complement their textual content. In addition, the games and activities from all the tutorials are available together on a page accessible from the homepage. Within the tutorials, students learn about topics such as sunspots and the solar wind in the sun tutorial and space-based and Earth-based research tools in the research and modeling tutorial. Copyright 2005 Eisenhower National Clearinghouse

National Aeronautics and Space Administration (NASA)

2005-01-01

462

Jet Streams and Weather  

NSDL National Science Digital Library

In this lesson, students learn about jet streams and explore the effects the polar-front jet stream has on weather conditions in North America. They begin by doing an interactive activity that highlights the atmospheric conditions and phenomena that create jet streams. They then look at a model that illustrates the relationships between latitude and variations in air temperature, wind speed, and altitude and begin to make generalizations about these relationships. In the second part of this lesson, they use the knowledge gained in the first part to interpret weather maps, helping them to make direct connections between the behavior of the polar-front jet stream and seasonal weather patterns in North America. As a final exercise, they will use real data to deepen their understanding of the relationships between pressure, altitude, and the wind speed of jet streams.

2005-01-01

463

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.

Mary Gorte

464

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.

465

Web Weather for Kids!  

NSDL National Science Digital Library

Web Weather for Kids offers hands-on classroom activities for students to learn about selected severe weather phenomena. Each activity has step-by-step instructions, materials lists, and guiding questions for students. A Teacher Tips page offers implementation strategies for teachers. Phenomena covered include the formation of thunderstorms, lightning, and tornados. Students explore the concepts of convection currents, precipitation, static electricity, wind shear and supercell updraft. Estimating the distance to a storm using the time delay between a flash of lightning and the sound of thunder is explained, as is what to do if caught near an electrical storm. Short videos of students involved in the activities enhance the site, as do links to more extensive information on the science of severe weather.

Susan Foster

466

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

467

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based module uses hands-on activities and real-time data investigations to allow students in the elementary grades 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 lesson plans which make up this module have been designed to allow teachers to select the ones which fit into their curriculum to allow for flexibility in implementation

2003-01-01

468

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.

469