Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

9,123 Full-Text Articles 15,057 Authors 1,364,851 Downloads 153 Institutions

All Articles in Earth Sciences

Faceted Search

9,123 full-text articles. Page 1 of 153.

Morphology And Morphometry Of Double Layered Ejecta Craters On Mars, Ryan Schwegman 2015 The University of Western Ontario

Morphology And Morphometry Of Double Layered Ejecta Craters On Mars, Ryan Schwegman

Electronic Thesis and Dissertation Repository

Double layered ejecta (DLE) craters display two distinct layers of ejecta that appear to have been emplaced as a mobile, ground-hugging flow. While volatile content within the target, atmosphere, or some combination of the two is generally considered a major variable enhancing the mobility of ejecta, the presence of unconsolidated surface materials may also have some effect. This statement is studied further here, aiming to determine whether bulk target lithology and/or attributes of the surface have any effect on morphometric properties between DLEs situated on sedimentary targets to those on volcanic ones. Results suggest that ejecta mobility (the distance ...


Reconstructing Late Holocene Hydrographic Variability Of The Gulf Of Maine, Nina Millicent Whitney 2015 University of Maine - Main

Reconstructing Late Holocene Hydrographic Variability Of The Gulf Of Maine, Nina Millicent Whitney

Electronic Theses and Dissertations

I present an annually resolved reconstruction of seawater temperatures in the

western North Atlantic from 1695-1915. This paleoclimate record was constructed

using oxygen isotopes measured in precisely dated Arctica islandica shells collected

off of Seguin Island in the western Gulf of Maine. The temperature reconstruction

was derived from this oxygen isotope time series using a modern d18Ow-salinity

mixing line developed for coastal waters in the Gulf of Maine from water samples

collected over the last decade. The d18Ow and salinity composition of these water

samples indicate that coastal surface waters consist of a ...


Cover Crop Biomass Production And Water Use In The Central Great Plains, David C. Nielsen, Drew J. Lyon, Gary W. Hergert, Robert K. Higgins, Johnathon D. Holman 2015 USDA-ARS

Cover Crop Biomass Production And Water Use In The Central Great Plains, David C. Nielsen, Drew J. Lyon, Gary W. Hergert, Robert K. Higgins, Johnathon D. Holman

David C. Nielsen

The water-limited environment of the semiarid Central Great Plains may not produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater water use efficiency than single-species plantings. This study was conducted to determine differences in cover crop biomass production, water use efficiency, and residue cover between a mixture and single-species plantings. The study was conducted at Akron, CO, and Sidney, NE, during the 2012 and 2013 growing seasons under both rainfed and irrigated conditions. Water use, biomass, and ...


High Resolution Stratigraphy And Paleoenvironmental Reconstruction Of The Upper Devonian Kettle Point Formation, Southwestern Ontario, Canada, Nikole E. Bingham-Koslowski 2015 The University of Western Ontario

High Resolution Stratigraphy And Paleoenvironmental Reconstruction Of The Upper Devonian Kettle Point Formation, Southwestern Ontario, Canada, Nikole E. Bingham-Koslowski

Electronic Thesis and Dissertation Repository

The Upper Devonian Kettle Point Formation of southwestern Ontario consists of interbedded organic-rich black shales and organic-poor greyish green mudstones and red beds, the distribution of which were controlled by water depth, primary productivity, paleoclimate, and tectonism associated with the concurrent Acadian orogeny. Black shales were deposited under anoxic conditions and represent the background deposition. Less abundant organic-poor lithologies were formed under dysoxic to oxic conditions caused by a drop in relative sea level (either eustatic or related to subsidence or uplift). Sulphur isotope data shows a largely consistent background value for the black shales around -20‰ δ34S ...


Identification Of Ancient Maya Agriculture In The Periphery Of Motul De San José, Alexandra E. Smofsky 2015 The University of Western Ontario

Identification Of Ancient Maya Agriculture In The Periphery Of Motul De San José, Alexandra E. Smofsky

Electronic Thesis and Dissertation Repository

Agricultural systems were investigated in the Motul de San José periphery, an ancient Maya polity in Guatemala, using soil geochemical techniques. The δ13C values of soil organic matter delineated areas of ancient maize agriculture at the satellite center of Kante’t’u’ul. A new method to locate areas of former cacao cultivation or processing was developed using HPLC to detect theobromine, an alkaloid of the cacao plant, preserved in soils. Extraction of spiked soils revealed that theobromine adsorption is inversely correlated with organic matter content of soils. Detection of naturally occurring theobromine was successful, demonstrating its utility ...


Evaluation Of Regional Climate Models With Remotely Sensed Evapotranspiration Data, Doruk Ozturk 2015 University 0f Nebraska-Lincoln

Evaluation Of Regional Climate Models With Remotely Sensed Evapotranspiration Data, Doruk Ozturk

Dissertations & Theses in Earth and Atmospheric Sciences

Water is one of the most precious resources on Earth. Managing water resources is a complex discipline that requires accurate data, which in turn means that the management of water resources is limited by the availability and quality of these datasets. Evapotranspiration (ET) is one of these key datasets, but is also one that is lacking in large-scale spatial distribution with traditional methods such as weighing lysimeters or Bowen ratio. This is a quantity that needs to be evaluated in regional and global climate models since it is a substantial component of the land surface-atmosphere interaction. In order to overcome ...


Topographic Signatures Of Geodynamics, Samuel G. Roy 2015 Earth and Climate Sciences

Topographic Signatures Of Geodynamics, Samuel G. Roy

Electronic Theses and Dissertations

The surface of the Earth retains an imperfect memory of the diverse geodynamic, climatic, and surface transport processes that cooperatively drive the evolution of Earth. In this thesis I explore the potential of using topographic analysis and landscape evolution models to unlock past and/or present evidence for geodynamic activity. I explore the potential isolated effects of geodynamics on landscape evolution, particularly focusing on two byproducts of tectonic strain: rock displacement and damage. Field evidence supports a strong correlation between rock damage and erodibility, and a numerical sensitivity analysis supports the hypothesis that an order of magnitude weakening in rock ...


Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur 2015 The University of Western Ontario

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected ...


Bioactivity Effect Of Two Macrophytes Extracts On Growth Performance Of Two Bloom-Forming Cyanophytes, Mary Guendy Ghobrial, H. S. Nassr, A. W. Kamil 2015 University of Windsor

Bioactivity Effect Of Two Macrophytes Extracts On Growth Performance Of Two Bloom-Forming Cyanophytes, Mary Guendy Ghobrial, H. S. Nassr, A. W. Kamil

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Governance Of Oil/Gas Sector In Nigeria: Impacts On Water Resources In The Niger-Delta Region, Felix Olufemi Ogele 2015 Newcastle University

Governance Of Oil/Gas Sector In Nigeria: Impacts On Water Resources In The Niger-Delta Region, Felix Olufemi Ogele

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Challenges In Environmental Governance: A Case Study Of Risk Perceptions Of Environmental Agencies Involved In Flood Management In The Hawesbury-Nepean Region, Australia, S. Masud 2015 University of New South Wales

Challenges In Environmental Governance: A Case Study Of Risk Perceptions Of Environmental Agencies Involved In Flood Management In The Hawesbury-Nepean Region, Australia, S. Masud

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Different Nitrogen Forms And Denitrifying Bacteria Space Distribution Characteristics In Surface Sediments Of Different Outfalls Of Nanfei River, C. Yang, S. Shen 2015 Tongji University

Different Nitrogen Forms And Denitrifying Bacteria Space Distribution Characteristics In Surface Sediments Of Different Outfalls Of Nanfei River, C. Yang, S. Shen

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Participatory Approach Of River Conservation With Special Focus To Bagmati River, Nepal, Khey Raj Dahal, Ganga Ram Prajapati 2015 Kantipur Engineering College, Nepal

Participatory Approach Of River Conservation With Special Focus To Bagmati River, Nepal, Khey Raj Dahal, Ganga Ram Prajapati

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Rice Husk Derived Engineered Biochar For Glyphosate Removal In Aqueous Media, Indika Herath Mr 2015 Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Hantana Road, Kandy 20000, Sri Lanka

Rice Husk Derived Engineered Biochar For Glyphosate Removal In Aqueous Media, Indika Herath Mr

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Simpler But Not Worse: Comparing Two Methods For Mapping Soil Conservation Service Of Terrestrial Ecosystems, Yihe Lv, Liwei Zhang, Bojie Fu 2015 Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences

Simpler But Not Worse: Comparing Two Methods For Mapping Soil Conservation Service Of Terrestrial Ecosystems, Yihe Lv, Liwei Zhang, Bojie Fu

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Endophytes: An Indicator For Improved Phytoremediation Of Environmental Pollutants, R. O. Anyasi, H. I. Atagana 2015 University of South Africa

Endophytes: An Indicator For Improved Phytoremediation Of Environmental Pollutants, R. O. Anyasi, H. I. Atagana

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Characterization And Phytoremediation Of Crude Oil Contaminated Wetland, E. O. Nwaichi, L. I. Opara, P. A. Nwoha 2015 University of Massachusetts - Amherst

Characterization And Phytoremediation Of Crude Oil Contaminated Wetland, E. O. Nwaichi, L. I. Opara, P. A. Nwoha

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Effect Of Oil And Dispersants From The Gulf Of Mexico On Estuarine Fish Species, Nancy D. Denslow, Olanike K. Adeyemo, Kevin J. Kroll 2015 University of Windsor

Effect Of Oil And Dispersants From The Gulf Of Mexico On Estuarine Fish Species, Nancy D. Denslow, Olanike K. Adeyemo, Kevin J. Kroll

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Determining The Most Sensitive Indicators For Each Species: A Cross-Species Comparison Of Passerines, D. S. Henshel, D. W. Sparks 2015 Indiana University - Bloomington

Determining The Most Sensitive Indicators For Each Species: A Cross-Species Comparison Of Passerines, D. S. Henshel, D. W. Sparks

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Trees Carbon Sequestration Of Different Reclamation Patterns In Antaibo Opencast Mine, Shanxi, China, Zhongqiu Zhao 2015 China University of Geoscience Beijing

Trees Carbon Sequestration Of Different Reclamation Patterns In Antaibo Opencast Mine, Shanxi, China, Zhongqiu Zhao

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.


Digital Commons powered by bepress