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2015

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Articles 871 - 900 of 1152

Full-Text Articles in Earth Sciences

Spatial-Temporal Analysis Of Seismicity Before The 2012 Varzeghan, Iran, Mw 6.5 Earthquake, Mohammad Talebi, Mehdi Zare, Rohollah Madahi Zadeh, Aref Bali-Lashak Jan 2015

Spatial-Temporal Analysis Of Seismicity Before The 2012 Varzeghan, Iran, Mw 6.5 Earthquake, Mohammad Talebi, Mehdi Zare, Rohollah Madahi Zadeh, Aref Bali-Lashak

Turkish Journal of Earth Sciences

In this work, the spatial and temporal variations of seismicity in northwestern Iran have been evaluated with a special focus on seismic precursors of the 11 August 2012 Mw 6.5 Varzeghan earthquake. The precursors are defined by the z-value test and the generalized fractal dimensions of earthquake epicenters. The investigation applies earthquakes that have occurred since 2006 in a region that includes the main shock and collected by the Iranian Seismological Center. In order to eliminate the effect of explosions in the processing, we removed the explosion from the used catalog by using the normalized ratio analysis of daytime to …


Rare Earth Element Geochemistry Of The Upper Permian Limestone: The Kanigorgeh Mining District, Nw Iran, Ali Abedini, Ali Asghar Calagari Jan 2015

Rare Earth Element Geochemistry Of The Upper Permian Limestone: The Kanigorgeh Mining District, Nw Iran, Ali Abedini, Ali Asghar Calagari

Turkish Journal of Earth Sciences

The limestone of the Ruteh Formation of Upper Permian age in the Kanigorgeh district (northeast of Bukan, NW Iran) contains several layers and lenses of bauxitic ores. Mineralogical data show that this limestone consists of calcite and quartz as major and plagioclase, kaolinite, and hematite as minor mineral phases. Geochemical analyses reveal that the proportions of ?REEs (La-Lu) in this limestone vary from 35.28 to 160.78 ppm. The values of Eu and Ce anomalies (normalized to PAAS) of the limestone have ranges of 1.11-1.68 and 0.89-1.16, respectively. The high values of ?REEs; low values of Y/Ho; strong and positive correlations …


Field Measurements For Remote Sensing Of The Cryosphere, Hans-Peter Marshall, Robert L. Hawley, Marco Tedesco Jan 2015

Field Measurements For Remote Sensing Of The Cryosphere, Hans-Peter Marshall, Robert L. Hawley, Marco Tedesco

CGISS Publications and Presentations

Remote sensing observations of the cryosphere, like any other target of interest, require ground-based measurements for both calibration and validation, as inversion algorithms are usually underdetermined and uncertainties in the retrieval are needed for application. Field-based observations are performed in selected representative locations, and typically involve both direct in situ measurements of the physical properties of interest, as well as ground-based remote sensing techniques.

New state-of-the-art modern techniques for measuring physical properties rapidly and at high spatial resolution have recently given us a new view of spatiotemporal variability. These are important, as large variability at scales below the typical footprint …


Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams Jan 2015

Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams

United States Environmental Protection Agency: Publications

Accurate quantification and clear understanding of regional scale cropland carbon (C) cycling is critical for designing effective policies and management practices that can contribute toward stabilizing atmospheric CO2 concentrations. However, extrapolating site-scale observations to regional scales represents a major challenge confronting the agricultural modeling community. This study introduces a novel geospatial agricultural modeling system (GAMS) exploring the integration of the mechanistic Environmental Policy Integrated Climate model, spatially-resolved data, surveyed management data, and supercomputing functions for cropland C budgets estimates. This modeling system creates spatiallyexplicit modeling units at a spatial resolution consistent with remotely-sensed crop identification and assigns cropping systems …


Detection, Occurrence And Fate Of Emerging Contaminants In Agricultural Environments, Daniel D. Snow, David A. Cassada, Shannon L. Bartelt-Hunt, Xu Li, Matteo D'Alessio, Rachel Levine, Yun Zhang, J. Brett Sallach Jan 2015

Detection, Occurrence And Fate Of Emerging Contaminants In Agricultural Environments, Daniel D. Snow, David A. Cassada, Shannon L. Bartelt-Hunt, Xu Li, Matteo D'Alessio, Rachel Levine, Yun Zhang, J. Brett Sallach

Nebraska Water Center: Faculty Publications

A total of 43 papers published in 2014 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to measuring and predicting biological effects for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, natural and synthetics steroids, and antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Occurrence and Fate, Antibiotic Resistance Genes, and Risk Assessment.


Nitrogen Management Of Forages In Relation To Gaseous Emissions – New Approaches And Considerations, Shabtai Bittman, Derek Hunt Jan 2015

Nitrogen Management Of Forages In Relation To Gaseous Emissions – New Approaches And Considerations, Shabtai Bittman, Derek Hunt

IGC Proceedings (1977-2023)

Forages have a high N demand, a long growing season, and an effective root system all contributing to effective nutrient capture. However forages are restrictive in methods available for mitigating gaseous losses both as NH3 and as N2O, due to both practical and cost considerations. Strategies are needed to address the challenges of both N efficiency and N losses. Agronomic techniques in long term experiments can enhance estimates of N loss pathways and N efficiency, and demonstrate the importance of integrated multinutrient approaches. The dual manure stream concept divides manure into a thin fraction suitable as an …


Impact Of Market Forces On Product Quality And Grassland Condition, David L. Michalk, Jianping Wu, Warwick B. Badgery, David R. Kemp Jan 2015

Impact Of Market Forces On Product Quality And Grassland Condition, David L. Michalk, Jianping Wu, Warwick B. Badgery, David R. Kemp

IGC Proceedings (1977-2023)

Meeting demands for livestock products which are predicted to more than double during the next 20 years, is central to the challenge of feeding the world sustainably. Smallholders will play a key role in achieving global security in animal protein. However, this requires a shift from subsistence to market-oriented farming where production efficiency not the number of livestock is the key focus with the aim of producing ‘more from less’. For grassland-based ruminant production, reducing stocking rate from current unsustainable levels under subsistence management is an essential first step to producing more production and profit from fewer animals. This is …


Stakeholders Integration For Sustainable Use Of Temperate Forage/Livestock Agriculture, Garry D. Lacefield, Don Ball Jan 2015

Stakeholders Integration For Sustainable Use Of Temperate Forage/Livestock Agriculture, Garry D. Lacefield, Don Ball

IGC Proceedings (1977-2023)

Forage/livestock production is complex, and best management options are often site-specific, but some concepts have broad application. The intent of this article is to provide an overview of research-based management approaches that the authors believe are necessary to ensure the sustainability of forage/livestock farms. This overview discussion is needed because livestock agriculture is changing, thus creating both challenges and opportunities for producers. In the last 30 years, beef numbers in the USA have declined by 20%, but production per cow has more than doubled, resulting in increased total production on less land with fewer animals. Similar statistics exist for the …


Socio-Cultural Factors Challenging Development Interventions In Cattle Production In The Remote Areas Of Vietnam, Duong-Nam Ha, Pham-Van Hung, Tran-The Cuong, Ninh-Xuan Trung, Tran-Van Long, Laurie Bonney, Peter A. Lane, Guillaume Duteurtre, Stephen Ives Jan 2015

Socio-Cultural Factors Challenging Development Interventions In Cattle Production In The Remote Areas Of Vietnam, Duong-Nam Ha, Pham-Van Hung, Tran-The Cuong, Ninh-Xuan Trung, Tran-Van Long, Laurie Bonney, Peter A. Lane, Guillaume Duteurtre, Stephen Ives

IGC Proceedings (1977-2023)

The northwest highlands of Vietnam are characterized by high altitude, low infrastructure, and low population densities composed of a wide diversity of different ethnic groups. Their socio-cultural characteristics strongly influence their lifestyle and production systems, including agricultural activities. The majority of these people have suffered from slow economic development, with the highest poverty rate in the country. This is a real need for plausible interventions where behavioral changes of smallholders throughout local value chains would be a critical foundation. Our project implemented in this context of development in the Northwest highlands of Vietnam aims to understand the role of socio-cultural …


Changing Grassland Scenario In Developing Countries--Economical And Social Perspective, Abule Ebro Jan 2015

Changing Grassland Scenario In Developing Countries--Economical And Social Perspective, Abule Ebro

IGC Proceedings (1977-2023)

Grasslands are mainly used for livestock production in developing countries although they have been facing contradictory pressures, i.e., increased demand for natural resources and animal products to cope with rising human populations. On the other, there is a need to preserve the environment and ecosystem. This paper reviewed the causes of grassland changes, the economic and social perspective of changing grasslands with more emphasis on dry lands. Different indicators were used to assess the economic (livestock production, wildlife and tourism, crop production, ecosystem services) and social (traditional institutions, mobility, land tenure and grazing systems) perspectives of changing grassland. The major …


Conservation Of Grassland Plant Genetic Resources Through People Participation, D. R. Malaviya, Ajoy K. Roy, P. Kaushal Jan 2015

Conservation Of Grassland Plant Genetic Resources Through People Participation, D. R. Malaviya, Ajoy K. Roy, P. Kaushal

IGC Proceedings (1977-2023)

Agrobiodiversity provides the foundation of all food and feed production. Hence, need of the time is to collect, evaluate and utilize the biodiversity globally available. Indian sub-continent is one of the world’s mega centers of crop origins. India possesses 166 species of agri-horticultural crops and 324 species of wild relatives. India is reported to have five grass covers identified. There have been almost nil human interference in terms of selection pressure; hence, the biodiversity is well conserved in these grazing lands. There is need of a system approach to understanding biodiversity that moves significantly beyond taxonomy and species observations. In …


Breeding Strategies To Improve Fodder Legumes With Special Emphasis On Clover And Medics, Ajoy K. Roy, D. R. Malaviya, P. Kaushal Jan 2015

Breeding Strategies To Improve Fodder Legumes With Special Emphasis On Clover And Medics, Ajoy K. Roy, D. R. Malaviya, P. Kaushal

IGC Proceedings (1977-2023)

In India, Forage has a unique integration of agriculture and animal industry in diversified rich cultural environment. Greater part of rural economy in India relies much upon mixed farming system, a well-knit combination of crop production and livestock rearing. In India, grazing-based livestock husbandry plays an important role in the rural economy as around 50% of animals depend on grazing. Pasturelands over an area of 12 Mha constitute the main grazing resources that are available. Nearly 30 pastoral communities in hilly or arid/semi-arid regions in northern and western parts of India, depend on grazing-based livestock production. Nomadic pastoralism, a traditional …


Front Matter [23rd International Grassland Congress Proceedings], National Organizing Committee, International Grassland Congress Jan 2015

Front Matter [23rd International Grassland Congress Proceedings], National Organizing Committee, International Grassland Congress

IGC Proceedings (1977-2023)

No abstract provided.


Improving Processing By Adaption To Conditional Geostatistical Simulation Of Block Compositions, R. Tolosana-Delgado, Ute A. Mueller, K. G. Van Den Boogaart, C. Ward, J. Gutzmer Jan 2015

Improving Processing By Adaption To Conditional Geostatistical Simulation Of Block Compositions, R. Tolosana-Delgado, Ute A. Mueller, K. G. Van Den Boogaart, C. Ward, J. Gutzmer

Research outputs 2014 to 2021

Exploitation of an ore deposit can be optimized by adapting the beneficiation processes to the properties of individual ore blocks. This can involve switching in and out certain treatment steps, or setting their controlling parameters. Optimizing this set of decisions requires the full conditional distribution of all relevant physical parameters and chemical attributes of the feed, including concentration of value elements and abundance of penalty elements. As a first step towards adaptive processing, the mapping of adaptive decisions is explored based on the composition, in value and penalty elements, of the selective mining units. Conditional distributions at block support are …


Inference Of Hydrogeological Conditions And Source History Of Groundwater Contaminants Using 3-D Modeling And Human Health Risk Assessment, Mary Rosanna Carnagie Jan 2015

Inference Of Hydrogeological Conditions And Source History Of Groundwater Contaminants Using 3-D Modeling And Human Health Risk Assessment, Mary Rosanna Carnagie

Wayne State University Theses

This study was completed using data interpolation and human health risk modules in Spatial Analysis and Decision Assistance (SADA) software to model a 3-D time-series of 1,4-dioxane and vinyl chloride plumes and their associated health risks to infer hydrogeological conditions at the Ann Arbor Landfill site. Ordinary kriging estimates of contaminant distribution and human health risk distribution provide insight to groundwater flow direction, hydraulic conductivity distribution, and source history of contaminants at sites with groundwater contamination in a glacial aquifer system. More studies with larger datasets in glacial aquifer systems are necessary to prove these correlations, but this thesis illustrates …


Impacts Of Anthropogenic Watershed Activity On The Sedimentary Record Of Dams From The Midwestern United States: A Case Study From Michigan And Indiana, Jenna Hage-Hassan Jan 2015

Impacts Of Anthropogenic Watershed Activity On The Sedimentary Record Of Dams From The Midwestern United States: A Case Study From Michigan And Indiana, Jenna Hage-Hassan

Wayne State University Theses

Large-scale watershed land use changes, including urbanization, have resulted in accelerated soil erosion and sediment accumulation rates, which in turn have posed a threat to the longevity and productivity of a majority of the aging dams in the mid-western United States. In this study, we collected and analyzed 3 sediment cores each from two dams from the Mid-western United States: Webber Dam in Michigan and Goshen Pond Dam in Indiana. Cores were analyzed for 137Cs and 210Pb to establish chronology, as well as concentrations and isotopic composition of organic carbon and nitrogen to investigate the land use changes as preserved …


Evaluation Of Hygroscopic Soil Amendments And Natural Freeze-Thaw Cycling To Accelerate The Mechanical Breakdown Of Artifacts In Demolition Site Soils, Phillip Joseph Backers Jan 2015

Evaluation Of Hygroscopic Soil Amendments And Natural Freeze-Thaw Cycling To Accelerate The Mechanical Breakdown Of Artifacts In Demolition Site Soils, Phillip Joseph Backers

Wayne State University Theses

Many cities worldwide have areas of vacant land produced by building demolition. This open space has attracted great interest as a potential resource for green infrastructure, urban agriculture, and other purposes related to urban renewal. Unfortunately, rock-like artifacts (e.g. brick, mortar, concrete) are often present in great abundance in demolition site soils. These artifacts make the soil difficult to till, create obstacles for root penetration, and limit the soil’s water-holding capacity, infiltration and aeration. As an alternative to physical removal, this study was carried out to test the feasibility of using hygroscopic compounds as soil amendments to accelerate the mechanical …


Changes In The Geometry And Volume Of Rabots Glaciär, Sweden, 2003-2011: Recent Accelerated Volume Loss Linked To More Negative Summer Balances, Keith A. Brugger, Latysha Pankratz Jan 2015

Changes In The Geometry And Volume Of Rabots Glaciär, Sweden, 2003-2011: Recent Accelerated Volume Loss Linked To More Negative Summer Balances, Keith A. Brugger, Latysha Pankratz

Geology Publications

Terminus geometry, ice margins, and surface elevations on Rabots glaciär were measured using differential GPS during summer 2011 and compared with those similarly measured in 2003. Glacier length over the eight years decreased by ∼105 m corresponding to 13 m a−1, a rate consistent with ice recession over the last several decades. Measured changes in surface elevations show that between 2003 and 2011 the glacier’s volume decreased by ∼27.6 ± 2.6 × 106 m3, or 3.5± 0.3 × 106 m3 a−1. This compares favorably with an estimate of −28.1 ± 2.6 × 106 m3 based on a mass-balance approach. The …


Schoenophyllum Aggregatum Zone: Stratigraphic Marker For Investigations Of Mississippian Limestones In Western Kentucky, Garland R. Dever Jr., Preston Mcgrain Jan 2015

Schoenophyllum Aggregatum Zone: Stratigraphic Marker For Investigations Of Mississippian Limestones In Western Kentucky, Garland R. Dever Jr., Preston Mcgrain

Report of Investigations--KGS

Schoenophyllum aggregatum, a Mississippian colonial rugose coral, has a widespread geographic distribution and narrow stratigraphic range in the upper Ste. Genevieve Limestone of western Kentucky. This coral zone serves as a useful stratigraphic marker for commercial and geologic investigations of the extensive limestone deposits formed by the Ste. Genevieve and enclosing limestone units in the region. S. aggregatum is also present in rocks correlative with the Ste, Genevieve that occur in the Monteagle Limestone Slade Formation of south-central Kentucky and the Newman Limestone of southeastern Kentucky.


Is There Space Inside Solid Rock?, Stephen F. Greb, David C. Harris, J. Richard Bowersox Jan 2015

Is There Space Inside Solid Rock?, Stephen F. Greb, David C. Harris, J. Richard Bowersox

Map and Chart--KGS

No abstract provided.


Mapped Karst Groundwater Basins In The Hopkinsville 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray, Phillip W. O'Dell, Robert J. Blair Jan 2015

Mapped Karst Groundwater Basins In The Hopkinsville 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray, Phillip W. O'Dell, Robert J. Blair

Map and Chart--KGS

No abstract provided.


A Potential Long-Lived Upper Cretaceous Paleodrainage System In The U.S. Southwestern Georgia-Southeastern Alabama Region, Daniel L. Black Jan 2015

A Potential Long-Lived Upper Cretaceous Paleodrainage System In The U.S. Southwestern Georgia-Southeastern Alabama Region, Daniel L. Black

Theses and Dissertations

The Gulf Coastal Plain unconformity separates crystalline basement of the Appalachian core from sedimentary units of the Coastal Plain. In the Columbus, Georgia region, basement rocks of the Uchee terrane are typically overlain by sands and gravels of the Tuscaloosa Formation. Sediments within the Tuscaloosa Formation indicate partial derivation from gneiss of the Columbus Metamorphic Complex, the nearby Pine Mountain belt and potentially rocks of Inner Piedmont-eastern Blue Ridge terranes. Mapping along the Coastal Plain unconformity near the Lower Chattahoochee River Valley indicates the presence of one or more large paleovalleys in the Upper Cretaceous sub-Coastal Plain surface that occupy …


Analyses Of Potential Ravine And Bluff Stabilization Sites Within The Blue Earth And Le Sueur River Basins, Anna My-Tien T. Tran Jan 2015

Analyses Of Potential Ravine And Bluff Stabilization Sites Within The Blue Earth And Le Sueur River Basins, Anna My-Tien T. Tran

All Graduate Theses, Dissertations, and Other Capstone Projects

The United States Environmental Protection Agency (USEPA) has listed much of the Upper Mississippi River (UMR) basin as impaired waters due to excessive turbidity, sedimentation, and nutrient loading. Of particular importance are the associated environmental problems (e.g. eutrophication, habitat and wetland loss, loss of biodiversity, and changes in water quality) that have developed within Lake Pepin, a popular recreational riverine lake of the UMR. Three major drainages contribute to these issues and empty in to the UMR near Lake Pepin - the Minnesota River Basin (MRB), St. Croix River, and UMR. The MRB makes up approximately one-third of the drainage …


Long-Term Litter Decomposition Controlled By Manganese Redox Cycling, Marco Keiluweit, Peter Nico, Mark E. Harmon, Jingdong Mao, Jennifer Pett-Ridge, Markus Kleber Jan 2015

Long-Term Litter Decomposition Controlled By Manganese Redox Cycling, Marco Keiluweit, Peter Nico, Mark E. Harmon, Jingdong Mao, Jennifer Pett-Ridge, Markus Kleber

Chemistry & Biochemistry Faculty Publications

Litter decomposition is a keystone ecosystem process impacting nutrient cycling and productivity, soil properties, and the terrestrial carbon (C) balance, but the factors regulating decomposition rate are still poorly understood. Traditional models assume that the rate is controlled by litter quality, relying on parameters such as lignin content as predictors. However, a strong correlation has been observed between the manganese (Mn) content of litter and decomposition rates across a variety of forest ecosystems. Here, we show that long-term litter decomposition in forest ecosystems is tightly coupled to Mn redox cycling. Over 7 years of litter decomposition, microbial transformation of litter …


Characterization Of Terrestrial Dissolved Organic Matter Fractionated By Ph And Polarity And Their Biological Effects On Plant Growth, Rachel L. Sleighter, Paolo Caricasole, Kristen M. Richards, Terry Hanson, Patrick G. Hatcher Jan 2015

Characterization Of Terrestrial Dissolved Organic Matter Fractionated By Ph And Polarity And Their Biological Effects On Plant Growth, Rachel L. Sleighter, Paolo Caricasole, Kristen M. Richards, Terry Hanson, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Background: Humic substances are ubiquitous in the environment, complex mixtures, and known to be beneficial to plant growth. To better understand and identify components responsible for plant growth stimulation, a terrestrial aquatic DOM sample was fractionated according to pH and polarity, obtaining acid-soluble and acid-insoluble portions, as well as acid-soluble hydrophobic and hydrophilic fractions using C18. The various fractions were characterized then evaluated for their biological effects on plant growth using bioassays with corn at two carbon rates.

Results: Approximately 43% and 57% of the carbon, and 31% and 69% of the iron, was found in the acid-insoluble and acid-soluble …


Habitat Assessment And Ecological Restoration Design For An Unnamed Tributary Of Stone Dam Creek, Conway, Arkansas, Paige E. Boyle, Mary C. Savin, James A. Mccarty, Marty D. Matlock Jan 2015

Habitat Assessment And Ecological Restoration Design For An Unnamed Tributary Of Stone Dam Creek, Conway, Arkansas, Paige E. Boyle, Mary C. Savin, James A. Mccarty, Marty D. Matlock

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Urbanization can lead to increased sedimentation, erosion, pollution, and runoff into streams. The United States Environmental Protection Agency’s (USEPA) Rapid Bioassessment Protocols (RBPs) are sets of guidelines that can be used to assess a habitat’s sedimentology, hydrology, vegetation, and geomorphology to determine impairment. An unnamed tributary of Stone Dam Creek on the University of Central Arkansas (UCA) campus in Conway, Arkansas runs partially underground and through the urbanized UCA campus watershed. The stream was assessed using the USEPA’s RBPs to determine impairment of the stream, and received a RBP score of 71.2 out of 200 compared to 153.5 in a …


Determination Of Vp, Vs, Glacial Drift Thickness And Poisson's Ratio At A Site In Jay County, Indiana, Using Seismic Refraction And Multichannel Analysis Of Surface Wave (Masw) Analysis On A Common Data Set, Shamim Ahammod Jan 2015

Determination Of Vp, Vs, Glacial Drift Thickness And Poisson's Ratio At A Site In Jay County, Indiana, Using Seismic Refraction And Multichannel Analysis Of Surface Wave (Masw) Analysis On A Common Data Set, Shamim Ahammod

Browse all Theses and Dissertations

In July 2013, an industry-scale seismic reflection survey was conducted at a site in northern Jay County, Indiana, by geophysics students and faculty of Wright State University. As a part of that effort, a separate near-surface seismic dataset was collected to examine the Vp, Vs, and Poisson's Ratio of the glacial drift and upper bedrock. This near-surface study successfully used a common dataset that was separately analyzed for both Vp (seismic refraction) and Vs (MASW) to calculate the Poisson's Ratio of the glacial drift and underlying bedrock. The driller's log for a water well near the east end of this …


Bedrock Mapping Using Shear Wave Velocity Characterization And H/V Analysis, James P. Gonsiewski Jan 2015

Bedrock Mapping Using Shear Wave Velocity Characterization And H/V Analysis, James P. Gonsiewski

Browse all Theses and Dissertations

An experiment was conducted to constrain the HVSR (Horizontal to Vertical Spectral Ratio) or H/V spectral ratio method at a glaciated site in northeast Ohio. Multiple methods were used to determine the shear wave velocity (Vs) and depth (h) to bedrock in relation to the fundamental resonant frequency (fo) determined from 3-component seismic data, as defined by the relationship f0=Vs/4h. The shear wave velocity structure was determined at three sites using MASW (Multi-channel Analysis of Surface Waves) and shear wave refraction methods, and the fundamental resonant frequency was passively observed using 3-component Guralp broadband seismometers. The …


Multi-Year Observations Of Breiðamerkurjökull, A Marine-Terminating Glacier In Southeastern Iceland, Using Terrestrial Radar Interferometry, Denis Voytenko, Timothy H. Dixon, Ian M. Howat, Noel Gourmelen, Chad Lembke, Charles L. Werner, Santiago De La Peña, Björn Oddsson Jan 2015

Multi-Year Observations Of Breiðamerkurjökull, A Marine-Terminating Glacier In Southeastern Iceland, Using Terrestrial Radar Interferometry, Denis Voytenko, Timothy H. Dixon, Ian M. Howat, Noel Gourmelen, Chad Lembke, Charles L. Werner, Santiago De La Peña, Björn Oddsson

School of Geosciences Faculty and Staff Publications

Terrestrial radar interferometry (TRI) is a new technique for studying ice motion and volume change of glaciers. TRI is especially useful for temporally and spatially dense measurements of highly dynamic glacial termini. We conducted a TRI survey of Breiðamerkurjökull, a marine-terminating glacier in Iceland, imaging its terminus near the end of the melt season in 2011, 2012 and 2013. The ice velocities were as high as 5 m d−1, with the fastest velocities near the calving front. Retreat of the glacier over the 3 year observation period was accompanied by strong embayment formation. Iceberg tracking with the radar shows high …


Did Shell-Crushing Crabs Trigger An Escalatory Arms Race In The Aftermath Of A Late Neogene Regional Mass Extinction Event? An Experimental Test, Lisa B. Whitenack, Gregory S. Herbert Jan 2015

Did Shell-Crushing Crabs Trigger An Escalatory Arms Race In The Aftermath Of A Late Neogene Regional Mass Extinction Event? An Experimental Test, Lisa B. Whitenack, Gregory S. Herbert

School of Geosciences Faculty and Staff Publications

A regional mass extinction event in the late Neogene western Atlantic is widely thought to have generated evolutionary opportunities for survivors, including enemy-related adaptation (escalation). The Strombus alatus species complex is one potential example of this phenomenon. Strombid gastropods are abundant in the Plio-Pleistocene fossil record and Recent in subtropical Florida, and the percentage of these shells bearing a row of short spines on the last whorl increased from nearly zero to almost 100% over this time. As shell ornamentation is one of the most frequently cited defenses against both peeling and crushing predators, we exposed live spined and spineless …