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Articles 48631 - 48660 of 59499
Full-Text Articles in Entire DC Network
Solar Forcing Of Gulf Of California Climate During The Past 2000 Yr Suggested By Diatoms And Silicoflagellates, John A. Barron, David Bukry
Solar Forcing Of Gulf Of California Climate During The Past 2000 Yr Suggested By Diatoms And Silicoflagellates, John A. Barron, David Bukry
United States Geological Survey: Staff Publications
High-resolution records of the past 2000 yr are compared in a north–south transect (28° N to 24° N) of three cores from the eastern slopes of the Guaymas, Carmen, and Pescadero Basins of the Gulf of California (hereafter referred to as the “Gulf”). Evenly-spaced samples from the varved sediments in each core allow sample resolution ranging from ∼ 16 to ∼ 37 yr.
Diatoms and silicoflagellates capture the seasonal variation between a late fall to early spring period of high biosiliceous productivity, that is driven by northwest winds, and a summer period of warmer, more stratified waters during which these …
Enhancing The Detection And Classification Of Coral Reef And Associated Benthic Habitats: A Hyperspectral Remote Sensing Approach, Deepak R. Mishra, Sunil Narumalani, Donald Rundquist, Merlin P. Lawson, R. Perk
Enhancing The Detection And Classification Of Coral Reef And Associated Benthic Habitats: A Hyperspectral Remote Sensing Approach, Deepak R. Mishra, Sunil Narumalani, Donald Rundquist, Merlin P. Lawson, R. Perk
Center for Advanced Land Management Information Technologies: Publications
Coral reefs and associated benthic habitats are heterogeneous in nature. A remote sensor designed to discriminate these environments requires a high number of narrow, properly placed bands which are not currently available in existing satellite sensors. Optical hyperspectral sensors mounted on aerial platforms seem to be appropriate for overcoming the lack of both high spectral and spatial resolution of satellite sensors. This research presents results of an innovative coral reef application by such a sensor. Using hyperspectral Airborne Imaging Spectroradiometer for Applications (AISA) Eagle data, the approach presented solves the confounding influence of water column attenuation on substrate reflectance on …
Hydrogeologic Setting And Ground-Water Flow Simulations Of The Eastern High Plains Regional Study Area, Nebraska, Matthew K. Landon, Michael J. Turco
Hydrogeologic Setting And Ground-Water Flow Simulations Of The Eastern High Plains Regional Study Area, Nebraska, Matthew K. Landon, Michael J. Turco
United States Geological Survey: Publications
The transport of anthropogenic and natural contaminants to public-supply wells was evaluated in a part of the High Plains aquifer near York, Nebraska, as part of the U.S. Geological Survey National Water-Quality Assessment Program. The aquifer in the Eastern High Plains regional study area is composed of Quaternary alluvial deposits typical of the High Plains aquifer in eastern Nebraska and Kansas, is an important water source for agricultural irrigation and public water supply, and is susceptible and vulnerable to contamination. A six-layer, steady-state ground-water flow model of the High Plains aquifer near York, Nebraska, was constructed and calibrated to average …
Land Capability Potential Index (Lcpi) For The Lower Missouri River Valley, Robert B. Jacobson, Kimberly A. Chojnacki, Joanna M. Reuter
Land Capability Potential Index (Lcpi) For The Lower Missouri River Valley, Robert B. Jacobson, Kimberly A. Chojnacki, Joanna M. Reuter
United States Geological Survey: Publications
The Land Capability Potential Index (LCPI) was developed to serve as a relatively coarse-scale index to delineate broad land capability classes in the valley of the Lower Missouri River. The index integrates fundamental factors that determine suitability of land for various uses, and may provide a useful mechanism to guide land-management decisions. The LCPI was constructed from integration of hydrology, hydraulics, land-surface elevations, and soil permeability (or saturated hydraulic conductivity) datasets for an area of the Lower Missouri River, river miles 423-670. The LCPI estimates relative wetness based on intersecting water-surface elevations, interpolated from measurements or calculated from hydraulic models, …
Movement Of A Large Landslide Block Dated By Tree-Ring Analysis, Tower Falls Area, Yellowstone National Park, Wyoming, Paul E. Carrara
Movement Of A Large Landslide Block Dated By Tree-Ring Analysis, Tower Falls Area, Yellowstone National Park, Wyoming, Paul E. Carrara
United States Geological Survey: Publications
Tree-ring analysis can be a valuable tool to date geomorphic events in regions lacking long historical records. In this study, the latest detectable movement of a section of a large landslide block in the Tower Falls area of Yellowstone National Park, Wyoming, is dated by tree-ring analysis of Douglas fir trees (Pseudotsuga menziesii var. glauca) damaged by the event. The movement tilted many of the trees and damaged their root systems. Thirteen old, tilted Douglas fir trees, at three sites, were sampled within the section of the landslide block that moved during the life of these trees. In …
Environmental Geochemistry In Yellowstone National Park—Natural And Anthropogenic Anomalies And Their Potential Impact On The Environment, Maurice A. Chaffee, Robert R. Carlson, Harley D. King
Environmental Geochemistry In Yellowstone National Park—Natural And Anthropogenic Anomalies And Their Potential Impact On The Environment, Maurice A. Chaffee, Robert R. Carlson, Harley D. King
United States Geological Survey: Publications
In cooperation with the National Park Service, the U.S. Geological Survey conducted a stream-sediment-based environmental geochemical study in and near Yellowstone National Park (the Park). The main goals of the study were to (1) determine background concentrations for as many as 49 elements in samples of rock and stream sediment, (2) establish a geochemical baseline during the 1990s for future reference, (3) identify the source(s) of anomalies for selected elements, and (4) identify potential chemical impacts on the Park environment, especially on wildlife.
Two areas of the Park containing identified environmental geochemical problems were selected for detailed study: (1) an …
Geochemical Data For Selected Rivers, Lake Waters, Hydrothermal Vents, And Subaerial Geysers In Yellowstone National Park, Wyoming And Vicinity, 1996–2004, Pamela A. Gemery-Hill, Wayne C. Shanks Iii, Laurie S. Balistrieri, Gregory K. Lee
Geochemical Data For Selected Rivers, Lake Waters, Hydrothermal Vents, And Subaerial Geysers In Yellowstone National Park, Wyoming And Vicinity, 1996–2004, Pamela A. Gemery-Hill, Wayne C. Shanks Iii, Laurie S. Balistrieri, Gregory K. Lee
United States Geological Survey: Publications
Analyses of more than 400 water samples collected from creeks and rivers draining into Yellowstone Lake, hydrothermal vents and water-column profiles within Yellowstone Lake, and subaerial hot springs and geysers throughout Yellowstone National Park (the Park) are reported. The samples were collected from 1996 to 2004. All of the water samples were collected and analyzed as part of the USGS Mineral Resources Program Project, Integrated Geoscience Studies of the Greater Yellowstone Area. Goals of this study are to provide state-of-the-art chemical determinations of more than 45 elements and species to help understand the influences of hydrothermal processes within Yellowstone National …
Spectral Analysis Of Absorption Features For Mapping Vegetation Cover And Microbial Communities In Yellowstone National Park Using Aviris Data, Raymond F. Kokaly, Don G. Despain, Roger N. Clark, K. Eric Livo
Spectral Analysis Of Absorption Features For Mapping Vegetation Cover And Microbial Communities In Yellowstone National Park Using Aviris Data, Raymond F. Kokaly, Don G. Despain, Roger N. Clark, K. Eric Livo
United States Geological Survey: Publications
This report summarizes the application of imaging spectroscopy to the study of biotic components of Yellowstone National Park ecosystems. Maps of vegetation cover and hot-spring microorganisms were generated using spectral-feature analysis of data from the airborne visible and infrared imaging spectrometer (AVIRIS). AVIRIS data were calibrated to surface reflectance using a radiative-transfer model and a ground-calibration target. A spectral library of canopy-reflectance signatures was created by averaging pixels of reflectance data over known occurrences of 27 vegetation cover types in Yellowstone. Distributions of these vegetation types were determined by comparing absorption features of the vegetation in the spectral library with …
Reconnaissance Study Of Pleistocene Lake And Fluvial Deposits In And Near Ancestral Yellowstone Lake, Wyoming, J. D. Love, John M. Good, D. G. Browne
Reconnaissance Study Of Pleistocene Lake And Fluvial Deposits In And Near Ancestral Yellowstone Lake, Wyoming, J. D. Love, John M. Good, D. G. Browne
United States Geological Survey: Publications
Seven sequences of Pleistocene strata, five of them predominantly lacustrine, are described from outcrops north of Yellowstone Lake. These are (1) Turbid Lake sequence, 30–50 feet of white pumiceous claystone and tuff with carbonaceous partings and a distinctive compositional pattern of excesses and deficiencies of many elements; (2) Yellowstone Falls sequence, 75 feet or more of varved white claystone and tuff containing pollen and diatoms, overlain by gray conglomerate and sandstone; (3) Hayden Valley sequence, 200 feet or more of gray and white silt and claystone containing sparse diatoms; (4) Alum Creek sequence, 30 feet or more of bedded sand …
Postglacial Inflation-Deflation Cycles, Tilting, And Faulting In The Yellowstone Caldera Based On Yellowstone Lake Shorelines, Kenneth L. Pierce, Kenneth P. Cannon, Grant A. Meyer, Matthew J. Trebesch, Raymond D. Watts
Postglacial Inflation-Deflation Cycles, Tilting, And Faulting In The Yellowstone Caldera Based On Yellowstone Lake Shorelines, Kenneth L. Pierce, Kenneth P. Cannon, Grant A. Meyer, Matthew J. Trebesch, Raymond D. Watts
United States Geological Survey: Publications
The Yellowstone caldera, like many other late Quaternary calderas of the world, exhibits dramatic unrest. Between 1923 and 1985, the center of the Yellowstone caldera rose nearly 1 m along an axis between its two resurgent domes (Pelton and Smith, 1979; Dzurisin and Yamashita, 1987). From 1985 until 1995–1996, the caldera subsided at about 2 cm/yr (Dzurisin and others, 1990). More recent radar-interferometry studies show renewed inflation of the northeastern resurgent dome between 1995 and 1996; this inflation migrated to the southwestern resurgent dome from 1996 to 1997 (Wicks and others, 1998).
We extend this record back in time using …
Effects Of Sorbate Speciation On Sorption Of Selected Sulfonamides In Three Loamy Soils, Sudarshan Kurwadkar, Craig Adams, Michael Meyer, Dana Kolpin
Effects Of Sorbate Speciation On Sorption Of Selected Sulfonamides In Three Loamy Soils, Sudarshan Kurwadkar, Craig Adams, Michael Meyer, Dana Kolpin
United States Geological Survey: Staff Publications
Sorption of sulfamethazine (SMN) and sulfathiazole (STZ) was investigated in three soils, a North Carolina loamy sand, an Iowa sandy loam, and a Missouri loam, under various pH conditions. A significant increase in the sorption coefficient (KD) was observed in all three soils, as the sulfonamides converted from an anionic form at higher pH to a neutral/cationic form at lower pH. Above pH 7.5, sulfonamides exist primarily in anionic form and have higher aqueous solubility and no cationic character, thereby consequently leading to lower sorption to soils. The effect of speciation on sorption is not the same …
Amphibians And Disease: Implications For Conservation In The Greater Yellowstone Ecosystem, Paul Stephen Corn
Amphibians And Disease: Implications For Conservation In The Greater Yellowstone Ecosystem, Paul Stephen Corn
United States Geological Survey: Staff Publications
The decline of amphibian populations is a worldwide phenomenon that has received increasing attention since about 1990. In 2004, the World Conservation Union’s global amphibian assessment concluded that 48% of the world’s 5,743 described amphibian species were in decline, with 32% considered threatened (Stuart et al. 2004). Amphibian declines are a significant issue in the western United States, where all native species of frogs in the genus Rana and many toads in the genus Bufo are at risk, particularly those that inhabit mountainous areas (Corn 2003a,b; Bradford 2005). As is true for most of the cold and dry Rocky Mountains, …
Geochemical Evidence For African Dust Inputs To Soils Of Western Atlantic Islands: Barbados, The Bahamas, And Florida, Daniel R, Muhs, James R. Budahn, Joseph M. Prospero, Steven N. Carey
Geochemical Evidence For African Dust Inputs To Soils Of Western Atlantic Islands: Barbados, The Bahamas, And Florida, Daniel R, Muhs, James R. Budahn, Joseph M. Prospero, Steven N. Carey
United States Geological Survey: Staff Publications
We studied soils on high-purity limestones of Quaternary age on the western Atlantic Ocean islands of Barbados, the Florida Keys, and the Bahamas. Potential soil parent materials in this region, external to the carbonate substrate, include volcanic ash from the island of St. Vincent (near Barbados), volcanic ash from the islands of Dominica and St. Lucia (somewhat farther from Barbados), the fine-grained component of distal loess from the lower Mississippi River Valley, and wind-transported dust from Africa. These four parent materials can be differentiated using trace elements (Sc, Cr, Th, and Zr) and rare earth elements that have minimal mobility …
Loess Sedimentation In Tibet: Provenance, Processes, And Link With Quaternary Glaciations, Jimin Sun, Sheng-Hua Li, Daniel R. Muhs, Bo Li
Loess Sedimentation In Tibet: Provenance, Processes, And Link With Quaternary Glaciations, Jimin Sun, Sheng-Hua Li, Daniel R. Muhs, Bo Li
United States Geological Survey: Staff Publications
Well-preserved loess deposits are found on the foothills of mountains along the middle reaches of the Yarlung Zangbo River in southern Tibet. Optically stimulated luminescence (OSL) dating is used to determine loess ages by applying the single-aliquot regeneration technique. Geochemical, mineralogical, and granulometric measurements were carried out to allow a comparison between loess from Tibet and the Chinese Loess Plateau. Our results demonstrate that (i) the loess deposits have a basal age of 13–11 ka, suggesting they accumulated after the last deglaciation, (ii) loess in southern Tibet has a ‘‘glacial’’ origin, resulting from eolian sorting of glaciofluvial outwash deposits from …
An Evaluation Of Selenium Concentrations In Water, Sediment, Invertebrates, And Fish From The Solomon River Basin, Thomas W. May, James F. Fairchild, Jim D. Petty, Michael J. Walther, Jeff Lucero, Mike Delvaux, Jill Manring, M. Armbruster
An Evaluation Of Selenium Concentrations In Water, Sediment, Invertebrates, And Fish From The Solomon River Basin, Thomas W. May, James F. Fairchild, Jim D. Petty, Michael J. Walther, Jeff Lucero, Mike Delvaux, Jill Manring, M. Armbruster
United States Geological Survey: Staff Publications
The Solomon River Basin is located in north-central Kansas in an area underlain by marine geologic shales. Selenium is an indigenous constituent of these shales and is readily leached into the surrounding groundwater. Portions of the Basin are irrigated primarily through the pumping of selenium-contaminated groundwater from wells onto fields in agricultural production. Water, sediment, macro-invertebrates, and fish were collected from various sites in the Basin in 1998 and analyzed for selenium. Selenium concentrations were analyzed spatially and temporally and compared to reported selenium toxic effect thresholds for specific ecosystem components: water, sediments, food-chain organisms, and whole-body fish. A selenium …
Integrating Laboratory Creep Compaction Data With Numerical Fault Models: A Bayesian Framework, Delphine D. Fitzenz, André Jalobeanu, Stephen H. Hickman
Integrating Laboratory Creep Compaction Data With Numerical Fault Models: A Bayesian Framework, Delphine D. Fitzenz, André Jalobeanu, Stephen H. Hickman
United States Geological Survey: Staff Publications
We developed a robust Bayesian inversion scheme to plan and analyze laboratory creep compaction experiments. We chose a simple creep law that features the main parameters of interest when trying to identify rate-controlling mechanisms from experimental data. By integrating the chosen creep law or an approximation thereof, one can use all the data, either simultaneously or in overlapping subsets, thus making more complete use of the experiment data and propagating statistical variations in the data through to the final rate constants. Despite the nonlinearity of the problem, with this technique one can retrieve accurate estimates of both the stress exponent …
Aquifer-Scale Controls On The Distribution Of Nitrate And Ammonium In Ground Water Near La Pine, Oregon, Usa, Stephen R. Hinkle, J. K. Böhlke, John H. Duff, David S. Morgan, Rodney J. Weick
Aquifer-Scale Controls On The Distribution Of Nitrate And Ammonium In Ground Water Near La Pine, Oregon, Usa, Stephen R. Hinkle, J. K. Böhlke, John H. Duff, David S. Morgan, Rodney J. Weick
United States Geological Survey: Staff Publications
Geochemical and isotopic tools were applied at aquifer, transect, and subtransect scales to provide a framework for understanding sources, transport, and fate of dissolved inorganic N in a sandy aquifer near La Pine, Oregon. NO3 is a common contaminant in shallow ground water in this area, whereas high concentrations of NH4– N (up to 39 mg/L) are present in deep ground water. N concentrations, N/Cl ratios, tracer- based apparent ground-water ages, N isotope data, and hydraulic gradients indicate that septic tank effluent is the primary source of NO3. N isotope data, N/Cl and N/C relations, …
Late Quaternary Paleoenvironments Of An Ephemeral Wetland In North Dakota, Usa: Relative Interactions Of Ground-Water Hydrology And Climate Change, Catherine H. Yansa, Walter E. Dean, Edward C. Murphy
Late Quaternary Paleoenvironments Of An Ephemeral Wetland In North Dakota, Usa: Relative Interactions Of Ground-Water Hydrology And Climate Change, Catherine H. Yansa, Walter E. Dean, Edward C. Murphy
United States Geological Survey: Staff Publications
This study of fossils (pollen, plant macrofossils, stomata and fish) and sediments (lithostratigraphy and geochemistry) from the Wendel site in North Dakota, USA, emphasizes the importance of considering ground-water hydrology when deciphering paleoclimate signals from lakes in postglacial landscapes. The Wendel site was a paleolake from about 11,500 14C yr BP to 11,100 14C yr BP. Afterwards, the lake-level lowered until it became a prairie marsh by 9,300 14C yr BP and finally, at 8,500 14C yr BP, an ephemeral wetland as it is today. Meanwhile, the vegetation changed from a white spruce parkland (11,500 to …
Adaptive Data-Driven Models For Estimating Carbon Fluxes In The Northern Great Plains, Bruce K. Wylie, Eugene A. Fosnight, Tagir G. Gilmanov, Albert B. Frank, Jack A. Morgan, Marshall R. Haferkamp, Tilden P. Meyers
Adaptive Data-Driven Models For Estimating Carbon Fluxes In The Northern Great Plains, Bruce K. Wylie, Eugene A. Fosnight, Tagir G. Gilmanov, Albert B. Frank, Jack A. Morgan, Marshall R. Haferkamp, Tilden P. Meyers
United States Geological Survey: Staff Publications
Rangeland carbon fluxes are highly variable in both space and time. Given the expansive areas of rangelands, how rangelands respond to climatic variation, management, and soil potential is important to understanding carbon dynamics. Rangeland carbon fluxes associated with Net Ecosystem Exchange (NEE) were measured from multiple year data sets at five flux tower locations in the Northern Great Plains. These flux tower measurements were combined with 1-km2 spatial data sets of Photosynthetically Active Radiation (PAR), Normalized Difference Vegetation Index (NDVI), temperature, precipitation, seasonal NDVI metrics, and soil characteristics. Flux tower measurements were used to train and select variables for …
Porosity And Permeability Of Bimodal Sediment Mixtures Using Natural Sediment, Peter M. Phillips
Porosity And Permeability Of Bimodal Sediment Mixtures Using Natural Sediment, Peter M. Phillips
Browse all Theses and Dissertations
Porosity and permeability are parameters that affect the flow of ground water in the subsurface and have significant implications on the modeling of fate and transport of contaminants. However, little has been done to quantitatively examine the effect on porosity and permeability of packing in bimodal mixtures of natural sediment. This study compares measurements of porosity and permeability on model bimodal sediment mixtures with predictions from petrophysical models. The main goal is to evaluate how well these petrophysical models predict porosity and permeability in bimodal mixtures of natural sediment. The effect of the volume fraction of fines on porosity and …
Identifying Fecal Sources In A Selected Catchment Reach Using Multiple Source-Tracking Tools, Jason R. Vogel, Donald M. Stoeckel, Regina Lamendella, Ronald B. Zelt, Jorge W. Santo Domingo, Steven R. Walker, Daniel B. Oerther
Identifying Fecal Sources In A Selected Catchment Reach Using Multiple Source-Tracking Tools, Jason R. Vogel, Donald M. Stoeckel, Regina Lamendella, Ronald B. Zelt, Jorge W. Santo Domingo, Steven R. Walker, Daniel B. Oerther
United States Geological Survey: Staff Publications
Given known limitations of current microbial source-tracking (MST) tools, emphasis on small, simple study areas may enhance interpretations of fecal contamination sources in streams. In this study, three MST tools—Escherichia coli repetitive element polymerase chain reaction (rep-PCR), coliphage typing, and Bacteroidales 16S rDNA host-associated markers—were evaluated in a selected reach of Plum Creek in south-central Nebraska. Water-quality samples were collected from six sites. One reach was selected for MST evaluation based on observed patterns of E. coli contamination. Despite high E. coli concentrations, coliphages were detected only once among water samples, precluding their use as a MST tool in …
Development Of The California Current During The Past 12,000 Yr Based On Diatoms And Silicoflagellates, John A. Barron, David Bukry
Development Of The California Current During The Past 12,000 Yr Based On Diatoms And Silicoflagellates, John A. Barron, David Bukry
United States Geological Survey: Staff Publications
Detailed diatom and silicoflagellates records in three cores from the offshore region of southern Oregon to central California reveal the evolution of the northern part of the California Current during the past 12,000 yr. The early Holocene, prior to ∼9 ka, was characterized by relatively warm sea surface temperatures (SST), owing to enhanced northerly flow of the subtropical waters comparable to the modern Davidson Current. Progressive strengthening of the North Pacific High lead to intensification of the southward flow of the California Current at ∼8 ka, resulting in increased coastal upwelling and relatively cooler SST which persisted until ∼5 ka. …
Sediment Geochemical Records Of Productivity And Oxygen Depletion Along The Margin Of Western North America During The Past 60,000 Years: Teleconnections With Greenland Ice And The Cariaco Basin, Walter E. Dean
United States Geological Survey: Staff Publications
Many sediment records from the margins of the Californias (Alta and Baja) collected in water depths between 60 and 1200m contain anoxic intervals (laminated sediments) that can be correlated with interstadial intervals as defined by the oxygen-isotope composition of Greenland ice (Dansgaard–Oeschger, D–O, cycles). These intervals include all or parts of Oxygen Isotope Stage 3 (OIS3; 60–24 cal ka), the Bolling/Allerod warm interval (B/A; 15–13 cal ka), and the Holocene. This study uses organic carbon (Corg) and trace-element proxies for anoxia and productivity, namely elevated concentrations and accumulation rates of molybdenum and cadmium, in these laminated sediments to suggest that …
Landscapes And Soils Of The Katanning District, D N. Sawkins, Department Of Agriculture And Food
Landscapes And Soils Of The Katanning District, D N. Sawkins, Department Of Agriculture And Food
Bulletins 4000 -
The publication aims to provide readers with the principles underlying the formation of local landscapes and soils, and the ability to identify landscapes and their associated soils.
Ground Water Level Monitoring At Yucca Mountain — A Programmatic Summary, H. Scott Page
Ground Water Level Monitoring At Yucca Mountain — A Programmatic Summary, H. Scott Page
Publications (YM)
Scope
- Confirmatory study supporting previously gathered information
- Measure levels on established network of monitoring wells
- Submit data annually
Objectives
- Provide measurements of known accuracy and precision
- Use manual and electronic equipment
- Provide quality assured data
- Contribute to hydrological understanding
- Support refinement of potentiometric surface
- Provide data for regional flow model
- Fulfill State of Nevada permit conditions
- Monitor transient events such as seismically induced fluctuations and precipitation-related phenomena
- Support long term monitoring and trend analysis
- Support proposed repository licensing application
Soils: A Contemporary Perspective, Cheryl Palm, Pedro Sanchez, Sonya Ahamed, Alex Awiti
Soils: A Contemporary Perspective, Cheryl Palm, Pedro Sanchez, Sonya Ahamed, Alex Awiti
East Africa Institute
Soils are viewed in the context of ecosystem services, soil processes and properties, and key attributes and constraints. The framework used is based on the premise that the natural capital of soils that underlies ecosystem services is primarily determined by three core soil properties: texture, mineralogy, and soil organic matter. Up-to-date descriptions and geographical distribution of soil orders as well as soil attributes and constraints are given, along with the relationships between soil orders, properties, and biomes. We then relate ecosystem services to specific soil processes, soil properties, and soil constraints and attributes. Soil degradation at present is not adequately …
Metastable Equilibria Among Dicarboxylic Acids And The Oxidation State During Aqueous Alteration On The Cm2 Chondrite Parent Body, Jason A. Mcalister, Richard M. Kettler
Metastable Equilibria Among Dicarboxylic Acids And The Oxidation State During Aqueous Alteration On The Cm2 Chondrite Parent Body, Jason A. Mcalister, Richard M. Kettler
Department of Earth and Atmospheric Sciences: Faculty Publications
Linear saturated dicarboxylic acids are present in carbonaceous chondrite samples at concentrations that suggest aqueous alteration under conditions of metastable equilibrium. In this study, previously published values of dicarboxylic acid concentrations measured in Murchison, Yamato-791198, and Tagish Lake carbonaceous chondrites are converted to aqueous activities during aqueous alteration assuming water:rock ratios that range from 1:10 to 10:1. Logarithmic plots of the aqueous activities of any two dicarboxylic acids are proximal to lines whose slope is fixed by the stoichiometry of reactions describing the oxidation–reduction equilibrium between the two species. The precise position of any line is controlled by the equilibrium …
Trace Element Distribution In Agate: Open Versus Closed System Formation, Michelle Leanna Tebbe
Trace Element Distribution In Agate: Open Versus Closed System Formation, Michelle Leanna Tebbe
Undergraduate Honors Theses
Agate is a silica-rich rock that preserves a record of ancient hydrology and water/rock interaction. However, there is little consensus on how agate forms. Two endmember formation models exist for agate hosted by basalt and are tested here by trace element investigation of agate samples from Brazil, Germany, and Washington, USA. Trace element abundances were analyzed by laser ablation ICP-MS and the data indicate crystallization in a closed system, at least on the scale of analysis in thin-section. Field data, X-ray diffraction data, and stable isotope analyses indicate that ~50 Ma agate from central Washington formed from heated meteoric water. …
There's A Whole Lotta Spillin' Goin' On!, Storm Project
There's A Whole Lotta Spillin' Goin' On!, Storm Project
Open Educational Resources
Unit Learning Objectives: The learner should be able to:
1. Compare and contrast hazardous chemical spills
2. Comprehend how hazardous chemicals affect the environment.
3. Explain the difficulty involved in cleaning up a
hazardous spill.
4. Explain how the chemical travels once it is released.
5. Assess how hazardous chemicals affect the human body and animal life.
6. Analyze a chemical spill and its affects on its
surroundings.
7. Create an emergency management system based on a real life situation
Evidence of Understanding: By the end of this unit, students should be able to demonstrate a clear understanding of hazardous …
What's The Temperature?, Storm Project
What's The Temperature?, Storm Project
Open Educational Resources
Objective : Students will be able to read a Fahrenheit and a Celsius thermometer, and correctly indicate temperatures on a thermometer diagram.
National Science Education Standards : All students should develop an understanding of: properties of earth materials, objects in the sky, changes in earth and sky. Weather changes from day to day and over the seasons. Weather can be described by measurable quantities, such as temperature, wind direction and speed, and precipitation.