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2011

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Articles 151 - 180 of 691

Full-Text Articles in Earth Sciences

Droughtscape, Summer 2011, Kelly Smith Jul 2011

Droughtscape, Summer 2011, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

New NDMC Website

Drought May Improve in Southeast and Southwest

Impacts Summary: Fire, Crop Loss and More

International Activities

NDMC Launches Ranch Planning Tool

Serving Data to Order

Workshop Builds Drought Planning Community


Penrose Conference Report: Neotectonics Of Arc-Continent Collision, Paul Mann, Carlos Vargas, Caroline Whitehill Jul 2011

Penrose Conference Report: Neotectonics Of Arc-Continent Collision, Paul Mann, Carlos Vargas, Caroline Whitehill

Geological Sciences Faculty Scholarship

Collisions of arcs with continents are some of the most significant tectonic processes on Earth, leading to crustal accretion, continental growth, formation of sedimentary basins, large areas of regional uplift and deformation, complex interactions between continuous and torn subducted slabs and the surrounding mantle, and large regions of large earthquakes and seismic, volcanic, and landslide hazards that can threaten the lives of millions.
The objective of this conference was to bring together an international group of scientists to discuss the neotectonics and seismic hazards of shallow slab subduction in areas of arc-continent collisions.


Techniques To Promote Garry Oak Seedling Growth And Survival In Areas With High Levels Of Herbivory And Competition, David R. Clements, Seth Luginbill, David A. Jordan, Randall Dragt Jul 2011

Techniques To Promote Garry Oak Seedling Growth And Survival In Areas With High Levels Of Herbivory And Competition, David R. Clements, Seth Luginbill, David A. Jordan, Randall Dragt

University Faculty Publications and Creative Works

Though regeneration of Garry oak (Quercus garryana) seedlings within Garry oak ecosystems is important to maintain this threatened habitat, seedling regeneration is often poor. Two independent studies were initiated in the early 2000s to examine questions surrounding Garry oak recruitment: one at the Crow's Nest Ecological Research Area (CNERA) on Salt Spring Island, BC, and another at the Pacific Rim Institute for Environmental Stewardship (PRI) on Whidbey Island, WA. In both areas, Garry oak seedlings were caged and monitored for growth and relative health. Over 8 years at CNERA, growth of caged plants outpaced growth of controls, which was indicative …


Mammalian Fauna From The Fullerton Gravel Pit (Ogallala Group, Late Miocene), Morton County, Kansas, Michael Anthony Calvello Jul 2011

Mammalian Fauna From The Fullerton Gravel Pit (Ogallala Group, Late Miocene), Morton County, Kansas, Michael Anthony Calvello

Master's Theses or Doctor of Nursing Practice

The Fullerton Gravel Pit, Morton County, Kansas is one of many sites in western Kansas at which the Ogallala Group crops out. The Ogallala Group was deposited primarily by streams flowing from the Rocky Mountains. Evidence of water transport is observable at the Fullerton Gravel Pit through the presence of allochthonous clasts, cross-bedding, pebble alignment, and fossil breakage and subsequent rounding. Fluvial mechanisms also played an important role in the distribution of fossil material. When the fossils from the Fullerton Gravel Pit are placed in Voorhies Groups, it appears that a majority of them were removed from suspension gradually and …


Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young Jul 2011

Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Sand Hills have been an important study area for dune activation and the nature of prehistoric drought events in the Great Plains. However, little has been done to understand the impact of these droughts to smaller dune fields along the eastern margin of the Great Plains. This study focuses on the Stanton dune field which is found about 145 km east of the Sand Hills along the southern edge of the Elkhorn River valley in northeastern Nebraska. With a wetter and slightly cooler climate regime than that of the Nebraska Sand Hills and most other central Great Plains …


New Stable Isotope Record Of Paleoecological Change In The Late Neogene Of The Western Great Plains From Enamel In Large Mammals, Zachary Kita Jul 2011

New Stable Isotope Record Of Paleoecological Change In The Late Neogene Of The Western Great Plains From Enamel In Large Mammals, Zachary Kita

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

An expansion of C4 grasslands occurred between 6 and 8 million years ago in the Great Plains of North America, as evidenced by a marked shift to more 13C-enriched carbon isotope compositions from large fossil mammal tooth enamel and paleosol carbonates. Prior to this expansion, habitats were comprised of exclusively C3 vegetation. To explore this problem I present a compilation of bulk stable carbon (δ13C) and oxygen (δ18O) isotope values from a variety of large mammals from 6 localities that span from the late Clarendonian to the late Blancan in Nebraska. As expected, …


The Nature, Origin And Preservation Of Amide Organic Nitrogen In Organic Matter, Georgina Anne Mckee Jul 2011

The Nature, Origin And Preservation Of Amide Organic Nitrogen In Organic Matter, Georgina Anne Mckee

Chemistry & Biochemistry Theses & Dissertations

Past studies have found much of nonliving sedimentary/aqueous nitrogen-containing organic matter (NCOM) is composed of amides, assumed to be peptides/proteins. Their lability calls into question their survival, and several hypotheses have been suggested to explain this. Using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and nuclear magnetic resonance (NMR) spectroscopy I investigated the molecular amide composition in sedimentary/aqueous systems while reassessing their preservation and formation routes.

Development of a suitable methodology is essential for successful NCOM study due to electrospray ionisation source requirements: sediment samples need to be rendered into solution. Based on NMR and FT-ICR-MS analysis, I determined …


Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa Jul 2011

Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Human activities such as conversion of natural ecosystem to croplands and urban-centers, deforestation and afforestation impact biophysical properties of land surface such as albedo, energy balance, and surface roughness. Alterations in these properties affect the heat and moisture exchanges between the land surface and atmospheric boundary layer. The objectives of this research were; (i) to quantitatively identify the High plains’ regional climate change in temperatures over the period 1895 to 2006, (ii) detect the signatures of anthropogenic forcing of LULC changes on the regional climate change of the High Plains, and (iii) examine the trends in evolving regional latent heat …


Evaluation Of Algorithm Thresholds For Crop Canopy Sensor-Based In-Season Nitrogen Application In Corn, Brian Theodore Krienke Jul 2011

Evaluation Of Algorithm Thresholds For Crop Canopy Sensor-Based In-Season Nitrogen Application In Corn, Brian Theodore Krienke

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen fertilizer is frequently the most limiting nutrient in corn production. Typically most nitrogen is applied before planting. Since nitrogen can leave the soil system fairly easily, the result can be an inefficient use of nitrogen fertilizer. Previous research has shown increased efficiency with no reduction in yield by applying nitrogen later in the season when the crop is actively growing, with rates regulated spatially through the use of active crop canopy sensors. This study evaluated the potential for N cutoff thresholds using a sufficiency index as the threshold value for areas with poor stand or an unrecoverable N deficiency. …


Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia Jul 2011

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia

Theses and Dissertations - UTB/UTPA

Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …


Insights Into Chemical Structure Changes Of Kerogen From Bituminous Coal In Response To Dike Intrusions Investigated By Advanced Solid-State 13C Nmr, Yuan Li Jul 2011

Insights Into Chemical Structure Changes Of Kerogen From Bituminous Coal In Response To Dike Intrusions Investigated By Advanced Solid-State 13C Nmr, Yuan Li

Chemistry & Biochemistry Theses & Dissertations

Variations in the chemical structures of kerogens From highly volatile bituminous coal located near two igneous dike intrusions in the Illinois Basin were examined in detail by advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Spectral-editing techniques were used to identify specific functional groups. Direct polarization was used to quantify different functional groups. 1H-13C two- dimensional heteronuclear NMR was used to examine connectivities and proximities, and 1H-13C long-range recoupled dipolar dephasing was used to estimate aromatic cluster sizes. With decreasing distance to dike contacts and increasing thermal maturity (vitrinite reflectance R0 from …


Model-Based Analyses Of Nitrogen On The Mid-Atlantic Bight Continental Shelf, Tian Tian Jul 2011

Model-Based Analyses Of Nitrogen On The Mid-Atlantic Bight Continental Shelf, Tian Tian

OES Theses and Dissertations

The biogeochemistry of continental shelf systems is an important, but poorly quantified, component of the global cycling of nitrogen and carbon. In this study, simulations obtained from a one-dimensional (ID) biogeochemical model developed for the Middle Atlantic Bight (MAB) portion of the U.S. eastern continental shelf were analyzed to investigate nitrogen cycling processes. The 1D model included lower trophic level interactions and was forced by advective fields obtained from a corresponding three-dimensional biogeochemical model. Taylor and target diagram analyses, which compared in situ measurements of sea surface temperature (SST) and salinity, and chlorophyll and particulate organic carbon (POC) derived from …


Polygonal Sandcracks: Unique Sedimentary Desiccation Structures In Bahamian Ooid Grainstone, Bosiljka Glumac, H. Allen Curran, Sarah A. Motti, Madeline M. Weigner, Sarah Pruss Jul 2011

Polygonal Sandcracks: Unique Sedimentary Desiccation Structures In Bahamian Ooid Grainstone, Bosiljka Glumac, H. Allen Curran, Sarah A. Motti, Madeline M. Weigner, Sarah Pruss

Geosciences: Faculty Publications

Sandcracks, which are ubiquitous in Holocene eolian and beach backshore carbonate grainstone on Alligator Point, Cat Island, Bahamas, resemble polygonal mudcracks, but formed in ooid sand without muddy matrix. In experiments on Cat Island beach sand, sediment surfaces cracked polygonally in the absence of mud or biofi lms while drying at room temperature due to contraction generated by capillary effects related to surface tension attraction of interstitial water. Gravitational collapse of irregular open pores and repacking of sand grains due to loss of cohesion between particles caused by evaporation of water enhance the cracking process and appearance of polygons by …


Environmental History Of A Closed-Basin Lake In The Us Great Plains: Diatom Response To Variations In Groundwater Flow Regimes Over The Last 8500 Cal. Yr Bp, William O. Hobbs, Sherilyn C. Fritz, Jeffery R. Stone, Joseph J. Donovan, Eric C. Grimm, James E. Almendinger Jul 2011

Environmental History Of A Closed-Basin Lake In The Us Great Plains: Diatom Response To Variations In Groundwater Flow Regimes Over The Last 8500 Cal. Yr Bp, William O. Hobbs, Sherilyn C. Fritz, Jeffery R. Stone, Joseph J. Donovan, Eric C. Grimm, James E. Almendinger

Department of Earth and Atmospheric Sciences: Faculty Publications

Sediment records from closed-basin lakes in the Northern Great Plains (NGP) of North America have contributed significantly to our understanding of regional paleoclimatology. A high-resolution (near decadal) fossil diatom record from Kettle Lake, ND, USA that spans the last 8500 cal. yr BP is interpreted in concert with percent abundance of aragonite in the sediment as an independent proxy of groundwater flow to the lake (and thus lake water level). Kettle Lake has been relatively fresh for the majority of the Holocene, likely because of the coarse substrata and a strong connection to the underlying aquifer. Interpretation of diatom assemblages …


The Collaborative Colorado– Nebraska Unmanned Aircraft System Experiment, Adam L. Houston, Brian Argrow, Jack Elston, Jamie Lahowetz, Eric W. Frew, Patrick C. Kennedy Jul 2011

The Collaborative Colorado– Nebraska Unmanned Aircraft System Experiment, Adam L. Houston, Brian Argrow, Jack Elston, Jamie Lahowetz, Eric W. Frew, Patrick C. Kennedy

Department of Earth and Atmospheric Sciences: Faculty Publications

Unmanned aircraft (UA) can provide observations of atmospheric phenomena that are either difficult or impossible to obtain with existing platforms. It is for this reason that facilitating the maturation of this relatively new technology has become a high priority in the atmospheric sciences. This position is reflected in the 2007 National Research Council Decadal Survey, which states that unmanned aircraft technology “should be increasingly factored into the nation’s strategic plan for Earth science” (National Research Council 2007, p. 14). Moreover, the fiscal year 2008 budget for the National Oceanic and Atmospheric Administration (NOAA) featured an increased investment in unmanned aircraft …


Establishing Confidence In Surface Wave Determined Soil Profiles, Paul Michaels Jun 2011

Establishing Confidence In Surface Wave Determined Soil Profiles, Paul Michaels

CGISS Publications and Presentations

Surface waves can be used to determine the shear velocity profile from the ground surface to some depth limited by the spectral band of the seismic source. A number of factors influence the uncertainties of the determined profile. The field acquisition factors include the deployment geometry of geophones, the spectral characteristics of the geophones, recording instruments, and seismic source. A key data processing factor is the determination of a dispersion curve from the field recordings. Finally, there are important choices in conducting the inversion of the dispersion curve which leads to the final soil profile. Even if the field factors …


Building An Enhanced Drought Early Warning System (Dews): Tools And Services For Decision Support, Mark Svoboda Jun 2011

Building An Enhanced Drought Early Warning System (Dews): Tools And Services For Decision Support, Mark Svoboda

National Drought Mitigation Center: Faculty Publications

Outline

  • About the NDMC
  • Drought Early Warning System (DEWS) Overview
  • Tools (USDM, DIR, Atlas, VegDRI, + EPC/DRC)
  • NDMC and the National Integrated Drought Information System (NIDIS)
  • Toward a Global Drought Early Warning System (NIDIS)
  • Toward a Global Drought Early Warning System (GDEWS)
  • Summary
  • Q&A


The Use Of Large-Scale Climate Data To Predict Drought, River Flows, And Vegetation Over Central-Southwest Asia, Matthew Barlow Jun 2011

The Use Of Large-Scale Climate Data To Predict Drought, River Flows, And Vegetation Over Central-Southwest Asia, Matthew Barlow

2011 Symposium on Data-Driven Approaches to Droughts

Central-Southwest Asia is a semi-arid, economically stressed region where droughts have severe societal impacts in terms of agriculture, farming, access to fresh water for drinking, and sanitation. There are two sources of drought predictability for this area: the influence of predictable modes of large-scale climate variability at both seasonal and intraseasonal timescales, and the importance of the snow pack to warm season river flows and vegetation. Local data scarcity is a critical problem for the region, both for historical analysis and for real-time monitoring. However, analysis shows that satellite data can be used to provide a considerable amount of high-resolution …


Climatic Characterization And Response Of Water Resources To Climate Change In Limestone Areas: Some Considerations On The Importance Of Geological Setting, Di Matteo Lucio, Valigi Daniela, Cambi Costanza Jun 2011

Climatic Characterization And Response Of Water Resources To Climate Change In Limestone Areas: Some Considerations On The Importance Of Geological Setting, Di Matteo Lucio, Valigi Daniela, Cambi Costanza

2011 Symposium on Data-Driven Approaches to Droughts

It is worldwide recognized and accepted that, in Southern Europe and the Mediterranean area in the last hundred years, the atmospheric temperature has risen by about 1°C, accompanied by a general decrease in precipitation. The trends detected in historical thermo-pluviometric series recorded in South/Central Italy show a general decrease in precipitation on an annual scale and a concentration of negative trends in the months from October to March. Analysis of the Standard Precipitation Index for the period 1951-2008 indicates higher frequency and duration of droughts in the last two decades: four prolonged dry periods (each lasting for up to three …


Droughts In The 21st Century And Beyond, Vijay P. Singh, Chris Funk, Jim Angel, Mark Svoboda Jun 2011

Droughts In The 21st Century And Beyond, Vijay P. Singh, Chris Funk, Jim Angel, Mark Svoboda

National Drought Mitigation Center: Faculty Publications

Drought: Science

  • Characterization
  • Mechanisms
  • Modelings
  • Prediction and Forecasting

Drought Monitoring

  • Measurement
  • Mapping
  • Space
  • Time
  • Data Sharing
  • Updating


Monitoring Drought Across Many Scales, Chris Funk Jun 2011

Monitoring Drought Across Many Scales, Chris Funk

2011 Symposium on Data-Driven Approaches to Droughts

Monitoring drought across many scales Chris Funk As gas and food prices increase while per capita harvested area decreases, drought and disruptions in food availability exert more and more pressure on the political and economic stability of ‘frailed’ states. Improved drought monitoring across many spatial and temporal time scales has therefore become increasingly important. As this need mounts, so have our capacities to observe and understand the earth’s climate. Relatively new satellite systems, such as the Moderate Resolution Imaging Spectrometer, allow us to watch the earth at scales of ~100 meters. Improved rainfall retrievals give us more timely and accurate …


An Update On Noaa’S National Integrated Drought Information System, Doug Kluck Jun 2011

An Update On Noaa’S National Integrated Drought Information System, Doug Kluck

2011 Symposium on Data-Driven Approaches to Droughts

NOAA through the National Integrated Drought Information System (NIDIS) supports planning and early warning preparedness amongst communities and states. Since the inception of NIDIS in 2006 there have been a series of regional drought projects across the United States that have begun to help different groups renew or begin to plan for drought. This presentation will briefly touch upon some of the successes those pilot projects have achieved and where they are headed. In addition and overview of NIDIS and the drought portal will be included.


Abrupt Holocene Climate Change As An Important Factor For Human Migration In West Greenland, William J. D'Andrea, Yongsong Huang, Sherilyn C. Fritz, N. John Anderson Jun 2011

Abrupt Holocene Climate Change As An Important Factor For Human Migration In West Greenland, William J. D'Andrea, Yongsong Huang, Sherilyn C. Fritz, N. John Anderson

Department of Earth and Atmospheric Sciences: Faculty Publications

West Greenland has had multiple episodes of human colonization and cultural transitions over the past 4,500 y. However, the explanations for these large-scale human migrations are varied, including climatic factors, resistance to adaptation, economic marginalization, mercantile exploration, and hostile neighborhood interactions. Evaluating the potential role of climate change is complicated by the lack of quantitative paleoclimate reconstructions near settlement areas and by the relative stability of Holocene temperature derived from ice cores atop the Greenland ice sheet. Here we present high-resolution records of temperature over the past 5,600 y based on alkenone unsaturation in sediments of two lakes in West …


Slides: Risk Management Strategies Of The Upper Basin: Addressing Potential Shortages, Eric Kuhn Jun 2011

Slides: Risk Management Strategies Of The Upper Basin: Addressing Potential Shortages, Eric Kuhn

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Eric Kuhn, Colorado River Water Conservation District

15 slides


Slides: Thinking The Unthinkable, Lawrence J. Macdonnell Jun 2011

Slides: Thinking The Unthinkable, Lawrence J. Macdonnell

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Lawrence J. MacDonnell, University of Wyoming College of Law

7 slides


Filling The Gap: Commonsense Solutions For Meeting Front Range Water Needs: Executive Summary, Western Resource Advocates, Trout Unlimited, Colorado Environmental Coalition (U.S.) Jun 2011

Filling The Gap: Commonsense Solutions For Meeting Front Range Water Needs: Executive Summary, Western Resource Advocates, Trout Unlimited, Colorado Environmental Coalition (U.S.)

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

8 pages.

"February 2011"

Presented by Drew Beckwith, Water Policy Manager, Western Resource Advocates, on June 10th at Clyde O. Martz Summer Conference 2011, Navigating the Future of the Colorado River Basin

Full report available at: http://www.westernresourceadvocates.org/gap


Materials For Presentation: The Disappearing Colorado River, Lawrence J. Macdonnell Jun 2011

Materials For Presentation: The Disappearing Colorado River, Lawrence J. Macdonnell

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

7 pages.

"Western Economics Forum, Fall 2010"


Slides: Who Should Be At The Table, And What Should They Be Talking About?, Robert W. Adler Jun 2011

Slides: Who Should Be At The Table, And What Should They Be Talking About?, Robert W. Adler

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Robert W. Adler, James I. Farr Chair in Law, University of Utah, S.J. Quinney College of Law

9 slides


Slides: Smart Fallowing: New Strategies In Ag Forbearance, Bonnie Colby Jun 2011

Slides: Smart Fallowing: New Strategies In Ag Forbearance, Bonnie Colby

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Dr. Bonnie Colby, Department of Agriculture & Resource Economics, University of Arizona

34 slides


Slides: Long-Term Augmentation Of The Water Supply Of The Colorado River System, Les Lampe Jun 2011

Slides: Long-Term Augmentation Of The Water Supply Of The Colorado River System, Les Lampe

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Les Lampe, Colorado River Water Consultants, Las Vegas, Nevada

29 slides