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2012

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Articles 121 - 150 of 988

Full-Text Articles in Earth Sciences

Dinosaur Tracks And Trackways In The Escalante Member Of The Entrada Formation (Middle Jurassic), Twentymile Wash, Grand Staircase-Escalante National Monument, Utah, Robert L. Eves, Gayle L. Pollock, Larry E. Davis Sep 2012

Dinosaur Tracks And Trackways In The Escalante Member Of The Entrada Formation (Middle Jurassic), Twentymile Wash, Grand Staircase-Escalante National Monument, Utah, Robert L. Eves, Gayle L. Pollock, Larry E. Davis

The Compass: Earth Science Journal of Sigma Gamma Epsilon

No abstract provided.


Sigma Gamma Epsilon-News And Information, James Walters Sep 2012

Sigma Gamma Epsilon-News And Information, James Walters

The Compass: Earth Science Journal of Sigma Gamma Epsilon

No abstract provided.


Probing Local Wind And Temperature Structure Using Infrasound From Volcan Villarrica (Chile), Jeffrey B. Johnson, J. Anderson, O. Marcillo, S. Arrowsmith Sep 2012

Probing Local Wind And Temperature Structure Using Infrasound From Volcan Villarrica (Chile), Jeffrey B. Johnson, J. Anderson, O. Marcillo, S. Arrowsmith

Geosciences Faculty Publications and Presentations

We use the continuous and intense (∼107 W) infrasound produced by Volcan Villarrica (Chile) to invert for the local dynamic wind and temperature structure of the atmosphere. Infrasound arrays deployed in March 2011 at the summit (2826 m) and on the NNW flank (∼8 km distant at 825 m) were used to track infrasound propagation times and signal power. We model an atmosphere with vertically varying temperature and horizontal winds and use propagation times (ranging from 23 to 24 s) to invert for horizontal slowness (2.75–2.94 s/km) and average effective sound speeds (328–346 m/s) for NNW propagating infrasound. The …


U.S. Drought Monitor, September 4, 2012, Brian Fuchs Sep 2012

U.S. Drought Monitor, September 4, 2012, Brian Fuchs

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for September 4, 2012 (9/4/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle.


Analytical Modeling Of Irrigation And Land Use Effects On Streamflow In Semi-Arid Conditions: Frenchman Creek, Nebraska, Jonathan P. Traylor Sep 2012

Analytical Modeling Of Irrigation And Land Use Effects On Streamflow In Semi-Arid Conditions: Frenchman Creek, Nebraska, Jonathan P. Traylor

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

With proliferation of various numerical models, water budget studies commonly resort to numerical modeling techniques. However, availability and uncertainty in input data limit advantages of this approach. Often, analytical models capture the major traits of the watersheds and can assimilate important data. We developed a model for baseflow-dominated watersheds and apply it to Frenchman Creek in southwestern Nebraska. Frenchman Creek has experienced large streamflow reductions since the 1950s. The cause of these reductions is a combination of irrigation, conservation terrace construction, and other land use changes. However, the influence of each factor has not been well quantified. The objective of …


Retrieval Of Sub-Pixel-Based Fire Intensity And Its Application For Characterizing Smoke Injection Heights And Fire Weather In North America, David Peterson Sep 2012

Retrieval Of Sub-Pixel-Based Fire Intensity And Its Application For Characterizing Smoke Injection Heights And Fire Weather In North America, David Peterson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

For over two decades, satellite sensors have provided the locations of global fire activity with ever-increasing accuracy. However, the ability to measure fire intensity, know as fire radiative power (FRP), and its potential relationships to meteorology and smoke plume injection heights, are currently limited by the pixel resolution. This dissertation describes the development of a new, sub-pixel-based FRP calculation (FRPf) for fire pixels detected by the MODerate Resolution Imaging Spectroradiometer (MODIS) fire detection algorithm (Collection 5), which is subsequently applied to several large wildfire events in North America. The methodology inherits an earlier bi-spectral algorithm for retrieving sub-pixel …


General Brochure, University Of North Dakota. Energy And Environmental Research Center Sep 2012

General Brochure, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Brochure about the Energy & Environmental Research Center (EERC), including its philosophy, partnerships, program areas, history, and Centers of Excellence. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Nebraska's Wetlands: Their Wildlife And Ecology, Paul A. Johnsgard Sep 2012

Nebraska's Wetlands: Their Wildlife And Ecology, Paul A. Johnsgard

Conservation and Survey Division: Faculty and Staff Publications

1 An Overview of Nebraska's Wetlands

2 The Missouri Valley • Natural History Profiles of Some Missouri Valley Wetland Species • The Missouri Valley Wetlands

3 The Niobrara Valley Region • Natural History Profiles of Some Niobrara Valley Wetland Species • The Niobrara Valley Wetlands

4 The Platte Valley Region • Natural History Profiles of Some Platte Valley Wetland Species • The Central Platte Valley Wetlands • The North Platte Valley Wetlands

5 Other River Valley Wetlands • Natural History Profiles of Some Typical Riverine Species • The Elkhorn Valley Wetlands • The Loup Valley Wetlands • The Republican Valley …


A New Model For The Spectral Induced Polarization Signature Of Bacterial Growth In Porous Media, Andre Revil, Estella A. Atekwana, C. Zhang, Abderrahim Jardani, Schaun M. Smith Sep 2012

A New Model For The Spectral Induced Polarization Signature Of Bacterial Growth In Porous Media, Andre Revil, Estella A. Atekwana, C. Zhang, Abderrahim Jardani, Schaun M. Smith

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The complex conductivity of porous materials and colloidal suspensions comprises two components: an in-phase conductivity associated with electromigration of the charge carriers and a quadrature conductivity associated with the reversible storage of the charges at some polarization length scales. We developed a quantitative model to investigate the frequency domain induced polarization response of suspensions of bacteria and bacteria growth in porous media. Induced polarization of bacteria (α polarization) is related to the properties of the electrical double layer of the bacteria. Surface conductivity and α polarization are due to the Stern layer of counterions occurring in a brush of polymers …


Evidence For Low-Angle Normal Faulting In The Pumqu-Xianza Rift, Tibet, Patrick W. Monigle, John Nabelek, Jochen Braunmiller, N. Seth Carpenter Sep 2012

Evidence For Low-Angle Normal Faulting In The Pumqu-Xianza Rift, Tibet, Patrick W. Monigle, John Nabelek, Jochen Braunmiller, N. Seth Carpenter

School of Geosciences Faculty and Staff Publications

Low-angle normal faulting is widely discussed as a possible mechanism for continental extension, however, unambiguous evidence for seismogenic low-angle normal faulting is lacking. Here, we investigate seismicity along a short segment of the Pumqu-Xianza Rift (PXR) in southern Tibet, where the HiCLIMB seismic array recorded over 500 earthquakes between 2004 July and 2005 August. Hypocentres of the 40 best recorded earthquakes are approximately 20–25 km west of the rift and tightly clustered at about 10 km depth, consistent with moment tensor depths of the 11 largest (3.4 ≤Mw≤ 4.5) earthquakes. Events in this group have N-S striking …


Bioactive Trace Metal Distributions And Biogeochemical Controls In The Southern Ocean, Christopher Measures, Mariko Hatta, Maxime Grand Sep 2012

Bioactive Trace Metal Distributions And Biogeochemical Controls In The Southern Ocean, Christopher Measures, Mariko Hatta, Maxime Grand

Faculty Publications

Extensive sampling in many regions of the Southern Ocean has demonstrated that surface water concentrations of dissolved Fe are low enough to limit phytoplankton growth. In contrast, there is currently no evidence that other bioactive elements (e.g., Mn, Zn, Co) are similarly limiting. Although atmospheric input of dissolved Fe to Southern Ocean surface waters appears to be low, resuspension of sediments from shallow regions around islands and the Antarctic coastline can inject significant amounts of Fe into the surrounding waters, stimulating primary production and providing a natural laboratory for studying the response of biological systems to natural Fe fertilization processes. …


The Ross Sea: In A Sea Of Change, Walker O. Smith, Peter N. Sedwick, Kevin R. Arrigo, David G. Ainley, Alejandro H. Orsi Sep 2012

The Ross Sea: In A Sea Of Change, Walker O. Smith, Peter N. Sedwick, Kevin R. Arrigo, David G. Ainley, Alejandro H. Orsi

OES Faculty Publications

The Ross Sea, the most productive region in the Antarctic, reaches farther south than any body of water in the world. While its food web is relatively intact, its oceanography, biogeochemistry, and sea ice coverage have been changing dramatically, and likely will continue to do so in the future. Sea ice cover and persistence have been increasing, in contrast to the Amundsen-Bellingshausen sector, which has resulted in reduced open water duration for its biota. Models predict that as the ozone hole recovers, ice cover will begin to diminish. Currents on the continental shelf will likely change in the coming century, …


"In Space" Or "As Space"?: A New Model, Charles H. Smith, Megan Derr Aug 2012

"In Space" Or "As Space"?: A New Model, Charles H. Smith, Megan Derr

DLPS Faculty Publications

In this analysis natural systems are posed to subsystemize in a manner facilitating both structured information/energy sharing and an entropy maximization process projecting a three-dimensional, spatial, outcome. Numerical simulations were first carried out to determine whether n × n input-output matrices could, once entropymaximized, project a three-dimensional Euclidean metric. Only 4 × 4 matrices could; a small proportion passed the test. Larger proportions passed when grouped random patterns on and within two- and three-dimensional forms were tested. Topographical patterns within 31 stream basin systems in the state of Kentucky, USA, were then similarly investigated, anticipating that the spatial configuration of …


U.S. Drought Monitor, August 28, 2012, Brian Fuchs Aug 2012

U.S. Drought Monitor, August 28, 2012, Brian Fuchs

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for August 28, 2012 (8/28/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle.


Trace Element Soil Contamination At Urban Community Gardens In Washington, Dc, Adam J. Long Aug 2012

Trace Element Soil Contamination At Urban Community Gardens In Washington, Dc, Adam J. Long

Environmental Analysis Program Mellon Student Summer Research Reports

In recent years, urban gardening has become a popular form of environmental, food, and social justice. Urban community gardens such as those in Washington, DC can reduce the environmental footprint of food production, provide access to healthy produce in “food deserts,” and provide other social, educational, and even financial benefits. However, the rising popularity of urban gardening has put many people in close contact with urban soils, which are likely to contain various contaminants due to concentrated human activity over extended periods of time. This study investigates heavy metal soil contaminants found in community gardens located in Washington, DC. 45 …


U.S. Drought Monitor, August 21, 2012, Michael J. Brewer, Liz Love-Brotak Aug 2012

U.S. Drought Monitor, August 21, 2012, Michael J. Brewer, Liz Love-Brotak

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for August 21, 2012 (8/21/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle.


The Freak Wave Potential Of Tyhoon Swell, Nai-Kuang Liang Aug 2012

The Freak Wave Potential Of Tyhoon Swell, Nai-Kuang Liang

Journal of Marine Science and Technology–Taiwan

Freak waves are so-called rogue waves, which are considered nearly impossible according to traditional ocean wave theory and sometimes cause coastal and sea wrecks. There are already some hypotheses that explain freak wave occurrence. However, the moving wind system generates swells which can be enhanced by swell energy flux accumulation. A newlydefined parameter “Freak Wave Potential Index” Φ for the typhoon swell can manifest the possibility for a freak wave occurrence. This index can be correctly estimated, because actual typhoon datum is already known. The “Freak Wave Potential Index” concept may also be used for other moving wind systems.


Hydrologic Data Assimilation With A Hillslope-Scale-Resolving Model And L Band Radar Observations: Synthetic Experiments With The Ensemble Kalman Filter, Alejandro N. Flores, Rafael L. Bras, Dara Entekhabi Aug 2012

Hydrologic Data Assimilation With A Hillslope-Scale-Resolving Model And L Band Radar Observations: Synthetic Experiments With The Ensemble Kalman Filter, Alejandro N. Flores, Rafael L. Bras, Dara Entekhabi

Geosciences Faculty Publications and Presentations

Soil moisture information is critical for applications like landslide susceptibility analysis and military trafficability assessment. Existing technologies cannot observe soil moisture at spatial scales of hillslopes (e.g., 100 to 102 m) and over large areas (e.g., 102 to 105 km2) with sufficiently high temporal coverage (e.g., days). Physics-based hydrologic models can simulate soil moisture at the necessary spatial and temporal scales, albeit with error. We develop and test a data assimilation framework based on the ensemble Kalman filter for constraining uncertain simulated high-resolution soil moisture fields to anticipated remote sensing products, specifically NASA's Soil …


Design And Application Of Inter-Satellite Link In Weather Observation Constellation, Jeng-Shing Chern, Zuu-Chang Hong, Tsai-Lun Chien, Tzu-You Chen, Ji-Chien Dai Aug 2012

Design And Application Of Inter-Satellite Link In Weather Observation Constellation, Jeng-Shing Chern, Zuu-Chang Hong, Tsai-Lun Chien, Tzu-You Chen, Ji-Chien Dai

Journal of Marine Science and Technology–Taiwan

This paper presents the design and application analysis of the inter-satellite link technique in weather observation satellite constellation. A Walker parameter 18/18/4 satellite constellation with circular orbit at 837 km altitude and 60 degree inclination has been considered. The purposes are to take the weather cloud images of the area from 60 to 180 degree in eastern longitude and 0 to 60 degree in northern latitude, and to transfer the images back to Taiwan ground station as soon as possible. The STK [1] simulation software has been used in analyzing the effects of Doppler phenomenon, azimuth angle, elevation angle and …


Cursorial Adaptations In The Forelimb Of The Giant Short-Faced Bear, Arctodus Simus, Revealed By Traditional And 3d Landmark Morphometrics, Eric Randally Lynch Aug 2012

Cursorial Adaptations In The Forelimb Of The Giant Short-Faced Bear, Arctodus Simus, Revealed By Traditional And 3d Landmark Morphometrics, Eric Randally Lynch

Electronic Theses and Dissertations

The paleobiology of the Pleistocene North American giant short-faced bear, Arctodus simus, has eluded paleontologists for decades. Its more gracile form has led past researchers to myriad intepretations of the locomotion and feeding ecology of this species. While earlier studies have focused on craniodental morphology and simple postcranial indices, it is forelimb morphology that represents a direct compromise between locomotor and foraging behavior. The study here uses traditional and 3D landmark morphometrics to more completely compare the 3-dimensional shape of the major forelimb elements and their muscle attachment sites between A. simus, extant ursids, and other carnivorans. Results …


Investigating The Holocene History Of Eliot Glacier, Mount Hood, Oregon, Nadia Sittara Jones Aug 2012

Investigating The Holocene History Of Eliot Glacier, Mount Hood, Oregon, Nadia Sittara Jones

Dissertations and Theses

This research documents the Holocene glacial history of Mount Hood, Cascade Mountains, Oregon by analyzing a set of three lateral moraines abutting Eliot Glacier, the largest glacier on the mountain. This study seeks to: 1) establish the relative ages of these lateral moraines and 2) determine if these features represent distinct glacial advances. The hypothesis is that the lateral moraines for Eliot Glacier represent three distinct periods of glacial advance based on their position relative to the current glacier and other diagnostic indicators. Soil profiles of three positions (shoulder, backslope, and footslope) on the distal side of each lateral moraine …


Landmark Analysis Of Musteloid Carnassials Applied To Taxonomic Identification And Examination Of Sexual Dimorphism And Regional Morphotypes, Joel Alvin Christine Aug 2012

Landmark Analysis Of Musteloid Carnassials Applied To Taxonomic Identification And Examination Of Sexual Dimorphism And Regional Morphotypes, Joel Alvin Christine

Electronic Theses and Dissertations

Guy Wilson Cave (GWC) in Sullivan County, Tennessee holds many late Pleistocene mammal fossils. Based on visual morphology, several partial mandibles with lower carnassial from GWC appeared to be musteloids. Geometric morphometrics has been successfully used to identify fragmentary fossils, so a landmark based, 2 dimensional technique was applied to identify the GWC musteloids using the lower carnassial. Digital images of several GWC fossils and of extant reference musteloids were combined using morphometric programs tpsDIG1, tpsUtil, and tpsSuper. Statistical data analysis was performed in PASW Statistics. Results successfully separated Mephitis mephitis (striped skunk) from M. macroura (hooded skunk) and Martes …


U.S. Drought Monitor, August 14, 2012, Michael J. Brewer, Liz Love-Brotak Aug 2012

U.S. Drought Monitor, August 14, 2012, Michael J. Brewer, Liz Love-Brotak

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for August 14, 2012 (8/14/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle.


Predicting Decadal Trends And Transient Responses Of Radiocarbon Storage And Fluxes In A Temperate Forest Soil, C. A. Sierra, S. E. Trumbore, E. A. Davidson, Serita D. Frey, K. E. Savage, F. M. Hopkins Aug 2012

Predicting Decadal Trends And Transient Responses Of Radiocarbon Storage And Fluxes In A Temperate Forest Soil, C. A. Sierra, S. E. Trumbore, E. A. Davidson, Serita D. Frey, K. E. Savage, F. M. Hopkins

Faculty Publications

Representing the response of soil carbon dynamics to global environmental change requires the incorporation of multiple tools in the development of predictive models. An important tool to construct and test models is the incorporation of bomb radiocarbon in soil organic matter during the past decades. In this manuscript, we combined radiocarbon data and a previously developed empirical model to explore decade-scale soil carbon dynamics in a temperate forest ecosystem at the Harvard Forest, Massachusetts, USA. We evaluated the contribution of different soil C fractions to both total soil CO2 efflux and microbially respired C. We tested the performance of the …


Interseismic Strain Accumulation Along The Western Boundary Of The Indian Subcontinent, Walter Szeliga, Roger Bilham, Din Mohammad Kakar, Sarosh H. Lodi Aug 2012

Interseismic Strain Accumulation Along The Western Boundary Of The Indian Subcontinent, Walter Szeliga, Roger Bilham, Din Mohammad Kakar, Sarosh H. Lodi

All Faculty Scholarship for the College of the Sciences

Despite an overall sinistral slip rate of ≈3 cm/yr, few major earthquakes have occurred in the past 200 years along the Chaman fault system, the western boundary of the India Plate with the Eurasia Plate. GPS and InSAR data reported here indicate sinistral shear velocities of 8–17 mm/yr across the westernmost branches of the fault system, suggesting that a significant fraction of the plate boundary slip is distributed in the fold and fault belt to the east. At its southernmost on‐land segment (≈26°N), near the triple junction between the Arabia, Eurasia, and India Plates, we find the velocity across the …


U.S. Drought Monitor, August 7, 2012, Mark D. Svoboda Aug 2012

U.S. Drought Monitor, August 7, 2012, Mark D. Svoboda

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for August 7, 2012 (8/7/2012) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle.


Comparing Newly Built Wetlands In The Atchafalaya Bay, Louisiana And Sacramento-San Joaquin Delta, California, Lindsay L. Dunaj Aug 2012

Comparing Newly Built Wetlands In The Atchafalaya Bay, Louisiana And Sacramento-San Joaquin Delta, California, Lindsay L. Dunaj

LSU New Orleans Theses and Dissertations

This research investigated patterns in elevation change in newly built wetlands in the Atchafalaya delta, and newly restored wetlands in the Sacramento-San Joaquin River delta. RSETs were used to measure small changes in elevation, and soil cores were processed to examine mineral and organic contributions.

Elevation change was highly variable, responding to influences from water level, river discharge, storms and vegetation. Mineral matter consistently added more to the marsh soil through volumetric and gravimetric contributions. Organic contributions were not significantly different across sites, suggesting the type of emergent vegetation at a site may not be the most important factor.

Sites …


Electric Currents Due To Stress-Activated Positive Hole Charge Carriers In Ice, Cary T. Keller P.E., Friedemann T. Freund, Dale P. Cruikshank Aug 2012

Electric Currents Due To Stress-Activated Positive Hole Charge Carriers In Ice, Cary T. Keller P.E., Friedemann T. Freund, Dale P. Cruikshank

STAR Program Research Presentations

Jupiter’s satellite Europa, whose surface is composed of ice with a possible water ocean beneath, could conceivably serve as an abode for extraterrestrial life. This and other icy celestial bodies may contain organic macromolecular solid material that is produced when surface ices are exposed to ultraviolet radiation and/or electrical energy. Tidal and tectonic stresses or meteorite impacts in icy crusts may produce electrical discharges, which would provide the energy for in-situ synthesis of the organic solids. This electrical energy can be provided by positive hole charge carrier activation. Positive holes exhibit properties such as the ability to flow out of …


Exploration Of Charge Carriers In Obsidian, Ryan Nordvik, Friedemann Freund Aug 2012

Exploration Of Charge Carriers In Obsidian, Ryan Nordvik, Friedemann Freund

STAR Program Research Presentations

This research effort is part of an ongoing investigation into stress-activated positive hole charge carriers in common igneous and high-grade metamorphic rocks. The findings have already revealed potential early earthquake detection mechanisms and caused a re-think on the processes that could conceivably contribute to the formation of and evolution of life. Positive holes are defect electrons in the oxygen anion sub-lattice of silicate minerals that have demonstrated some intriguing capabilities: flowing out of a stressed rock volume; causing oxidation reactions at the rock-water interface and ionization at the rock-air interface; and traveling great distances. This research seeks to determine if …


Leds And Astronomy, Britny N. Delp, Stephen M. Pompea Aug 2012

Leds And Astronomy, Britny N. Delp, Stephen M. Pompea

STAR Program Research Presentations

Using a Czerny-Turner spectrometer, 45 different types of outdoor lights were categorized. These spectra were used to determine how useful the light is to human eyes and how dark skies friendly these lights are. Dark skies friendly lighting means that little to no light shines above a right angle to the light, and should emit as little as possible below 500nm (green) wavelengths. The short wavelengths present a problem to astronomers in the form of Rayleigh scattering. The following criterion were used in selecting the best source for urban and rural lighting: color rendition measured by color rendering index (CRI), …