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Articles 6271 - 6300 of 9408
Full-Text Articles in Entire DC Network
Natural Degradation Of Earthworks, Trenches, Walls And Moats, Northern Thailand, Spencer H. Wood, Layle R. Wood, Alan D. Ziegler
Natural Degradation Of Earthworks, Trenches, Walls And Moats, Northern Thailand, Spencer H. Wood, Layle R. Wood, Alan D. Ziegler
Geosciences Faculty Publications and Presentations
“………..structures of this kind are hidden away securely under the thick overgrowth: thus does nature preserve what man would surely destroy” (from Sumet Jumsai, 1970)
We investigate the geometry, age, and history of several enigmatic northern Thailand earthwork entrenchments that are mostly located on hills and could not have held water to form moats. The earthworks are either oval or rectangular in map view; and they typically encircle 0.3-to-1-km2 areas that do not have potsherd debris indicative of former towns. Most trenches are 3-5 m deep with inner walls 4.5-8 m high. Some encircling earthworks are concentric double trenches …
The Geotraces Intermediate Data Product 2014, The Geotraces Group, Tim M. Conway
The Geotraces Intermediate Data Product 2014, The Geotraces Group, Tim M. Conway
School of Geosciences Faculty and Staff Publications
The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in …
Infrasound From Volcanic Rockfalls, Jeffrey B. Johnson, Timothy J. Ronan
Infrasound From Volcanic Rockfalls, Jeffrey B. Johnson, Timothy J. Ronan
CGISS Publications and Presentations
Proximal infrasound arrays can robustly track rapidly moving gravity-driven mass wasting, which occurs commonly at erupting volcanoes. This study reports on detection, localization, and quantification of frequent small rockfalls and infrequent pyroclastic density currents descending the southeast flanks of Santiaguito’s active Caliente Dome in January of 2014. Such activities are identified as moving sources, which descend several hundred meters at bulk flow speeds of up to ~10 m/s, which is considerably slower than the descent velocity of individual blocks. Infrasound rockfall signal character is readily distinguishable from explosion infrasound, which is manifested by a relatively fixed location source with lower …
The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic
The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic
Biology Theses
Soil respiration, from plant roots and soil microbes, accounts for 60 – 80 percent of total ecosystem respiration, with the microbial component contributing approximately 54 percent. Global climate trends resulting from CO2 emissions include increased soil temperatures and changes in precipitation regimes resulting in less frequent, more intense rainfall events. Soil temperature and moisture availability drive soil respiration rates, but how they impact the microbial respiration is poorly qualified. I investigated how the soil microbial community responds to changes in temperature and moisture availability in a laboratory based experiment. Soils from a mixed hardwood forest under two thermal regimes …
Ediacaran Ocean Redox Evolution, Swapan Kumar Sahoo
Ediacaran Ocean Redox Evolution, Swapan Kumar Sahoo
UNLV Theses, Dissertations, Professional Papers, and Capstones
The relative role that environmental versus intrinsic biological factors played in
shaping the history of life on Earth is a fundamental but unanswered question in the
natural sciences. Most famously, it has been heavily debated if the emergence and
diversification of early animals during the Ediacaran Period (ca. 635–541 Ma) was tied to
a rise in atmospheric-oceanic oxygen levels. Temporally discontinuous geochemical data and patchy fossil record in literature are inadequate to chart the Ediacaran redox history and its causal relationship with the biotic evolution. My PhD study aims for a multiproxy geochemical record within a well-established stratigraphic framework of …
Glass Shards At Pinnacle Point Rock Shelter 5-~6, South Africa: Are They From The Last Super-~Eruption Of Toba?, Amber Elizabeth Ciravolo
Glass Shards At Pinnacle Point Rock Shelter 5-~6, South Africa: Are They From The Last Super-~Eruption Of Toba?, Amber Elizabeth Ciravolo
UNLV Theses, Dissertations, Professional Papers, and Capstones
Cryptotephra, in the form of individual glass shards, have been discovered in paleoarchaeological site PP5-6 North at Pinnacle Point, Western Cape, South Africa. This marks the first documentation of cryptotephra in a South African paleoarchaeological site. PP5-6 North is a rock shelter in the cliffs along the coast of the Western Cape and is one of a series of caves and rock shelters at Pinnacle Point that were inhabited by early modern humans. The presence of cryptotephra at PP5-6 is an important discovery in terms of tephra preservation in cave deposits as well as the possibility of tephra being present …
Deep Fluid Inputs Into The Continental-Scale Nubian Sandstone Aquifer System Constrained By Hydrochemical, Stable Isotope, And Noble Gas Data, Abdel Mawgoud Mohammed
Deep Fluid Inputs Into The Continental-Scale Nubian Sandstone Aquifer System Constrained By Hydrochemical, Stable Isotope, And Noble Gas Data, Abdel Mawgoud Mohammed
Dissertations
The Nubian Sandstone Aquifer System (NSAS) of northeastern Africa is one of the largest confined fossil-water aquifer systems in the world, with several nations relying on it (Egypt, Libya, Sudan and Chad). This groundwater is the biggest and in some cases the only future source of water to meet the development goals of each NSAS country. This study provides new geochemical data from the main oases of the Western Desert of Egypt and a compilation of published hydrochemical data from the regional aquifer. Interpretation of results suggests heterogeneous fluid mixing within the aquifer, the potential for hydrochemical sub-basins, and a …
Available Nitrogen And Denitrification In Soil Altered By Ground Cover And Nutrient Source In An Organic Apple Orchard, Jade Nicole Ford
Available Nitrogen And Denitrification In Soil Altered By Ground Cover And Nutrient Source In An Organic Apple Orchard, Jade Nicole Ford
Graduate Theses and Dissertations
A shift in public demand towards more organic and locally produced fruit and vegetables has been occurring across the United States in recent years. A common practice in organic fruit production is the application of organic ground covers to supply nutrients while enhancing other soil properties. A need for research exists in the southern region of the U.S. examining the effects of regionally applicable ground cover and nutrient management on nitrogen availability and the microbial community to provide information to organic farmers in the region. Two studies were conducted to determine how 12 treatment combinations of four ground covers (compost, …
A Comparative Analysis Of Portable X-Ray Fluorescence Spectrometry And Stable Isotopes In Assessing Ancient Coastal Peruvian Diets, Theresa Jane Gilbertson
A Comparative Analysis Of Portable X-Ray Fluorescence Spectrometry And Stable Isotopes In Assessing Ancient Coastal Peruvian Diets, Theresa Jane Gilbertson
USF Tampa Graduate Theses and Dissertations
This dissertation explores a cross-cultural analysis of the dietary signatures of four coastal cultures of prehistoric Peru. A combination of elemental analysis based on portable x-ray fluorescence spectrometry (pXRF), testing trace elements presented in 209 individuals’ skulls representing the Nazca (38), Cañete (33), Lima (40), and Moche (98) valleys and/or cultures of the first millennium AD, is weighed in conjunction with isotope ratio mass spectrometry (IRMS) to analyze human bone collagen and bone apatite derived from a portion of the individuals represented in the Nazca, Cañete, and Lima cranial samples.
Evidence from the results of both tests are weighed using …
Understanding Acceptable Level Of Risk: Incorporating The Economic Cost Of Under-Managing Invasive Species, Alisha D. Davidson, Chad L. Hewitt, Donna R. Kashian
Understanding Acceptable Level Of Risk: Incorporating The Economic Cost Of Under-Managing Invasive Species, Alisha D. Davidson, Chad L. Hewitt, Donna R. Kashian
Environmental Science and Geology Faculty Research Publications
Management of nonindigenous species includes prevention, early detection and rapid response and control. Early detection and rapid response depend on prioritizing and monitoring sites at risk for arrival or secondary spread of nonindigenous species. Such monitoring efforts require sufficient biosecurity budgets to be effective and meet management or policy directives for reduced risk of introduction. Such consideration of risk reduction is rarely considered, however. Here, we review the concepts of acceptable level of risk (ALOR) and associated costs with respect to nonindigenous species and present a framework for aligning risk reduction priorities with available biosecurity resources. We conclude that available …
Ua24 Mcicsl Newsletter - November 2015, Shannon R. Trimboli Education Coordinator
Ua24 Mcicsl Newsletter - November 2015, Shannon R. Trimboli Education Coordinator
MCICSL Newsletter
This issue includes the following:
Partners Recognized for Water Quality Research at Mammoth Cave National Park and Increasing Diversity in the Geosciences
Texas A&M – Galveston Students Participate in Citizen Science at Mammoth Cave National Park
Northern Kentucky University and the Mammoth Cave International Center for Science and Learning to Host Partners in the Parks Program at Mammoth Cave National Park
as well as education and research highlights, and MCICSL symposium information
The Founding Of The Robert B. Daugherty Water For Food Institute At The University Of Nebraska
The Founding Of The Robert B. Daugherty Water For Food Institute At The University Of Nebraska
Daugherty Water for Food Global Institute: Administrative Materials
University of Nebraska President J.B. Milliken drove to Omaha in to meet Robert Daugherty at his home. In the living room, the elder Daugherty was surrounded by Mogens Bay, his three sons and a covey of lawyers. Now 88 years old, the businessman had a reputation for being tough-minded and smart, a man who could intimidate, but also surprise with his ready sense of humor. In his long career, Daugherty had transformed agriculture and the rural landscape into the now familiar polka dot pattern, the signature of the center pivot irrigators Daugherty had popularized in the 1970s. He had started …
A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary
A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary
USF Tampa Graduate Theses and Dissertations
Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ15N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …
The Vulnerability Of Indo-Pacific Mangrove Forests To Sea-Level Rise, Catherine E. Lovelock, Donald R. Cahoon, Daniel A. Friess, Glenn R. Guntenspergen, Ken W. Krauss, Ruth Reef, Kerrylee Rogers, Megan L. Saunders, Frida Sidik, Andrew Swales, Neil Saintilan, Le Xuan Thuyen, Tran Triet
The Vulnerability Of Indo-Pacific Mangrove Forests To Sea-Level Rise, Catherine E. Lovelock, Donald R. Cahoon, Daniel A. Friess, Glenn R. Guntenspergen, Ken W. Krauss, Ruth Reef, Kerrylee Rogers, Megan L. Saunders, Frida Sidik, Andrew Swales, Neil Saintilan, Le Xuan Thuyen, Tran Triet
United States Geological Survey: Staff Publications
Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves1,2. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth3. The Indo- Pacific region holds most of the world’s mangrove forests4, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers5. This decline is of particular concern because the Indo-Pacific region is …
A Modern Gate For Ezells Cave, Texas, Jim "Crash" Kennedy
A Modern Gate For Ezells Cave, Texas, Jim "Crash" Kennedy
National Cave and Karst Management Symposia
No abstract provided.
Introducing The Junior Cave Scientist Program, Dale L. Pate
Introducing The Junior Cave Scientist Program, Dale L. Pate
National Cave and Karst Management Symposia
No abstract provided.
A Multidisciplinary Project For Sustainable Management Planning In Karst, Chiapas, Mexico, Johanna L. Kovarik
A Multidisciplinary Project For Sustainable Management Planning In Karst, Chiapas, Mexico, Johanna L. Kovarik
National Cave and Karst Management Symposia
No abstract provided.
Karst Wreckage: Subterranean Fauna As Collateral Damage, Julian J. Lewis, Salisa L. Lewis
Karst Wreckage: Subterranean Fauna As Collateral Damage, Julian J. Lewis, Salisa L. Lewis
National Cave and Karst Management Symposia
No abstract provided.
The Extirpation Of A Population Of The Endangered Illinois Cave Amphipod (Gammarus Acherondytes) By An Exotic Species: The Wednesday Cave Debacle, Julian J. Lewis, Salisa L. Lewis
The Extirpation Of A Population Of The Endangered Illinois Cave Amphipod (Gammarus Acherondytes) By An Exotic Species: The Wednesday Cave Debacle, Julian J. Lewis, Salisa L. Lewis
National Cave and Karst Management Symposia
No abstract provided.
Conservation And Touristic Use In Ballet Cave, Brazil: History, Present Situation And Future Outlook, Luciana Alt, Vitor Moura
Conservation And Touristic Use In Ballet Cave, Brazil: History, Present Situation And Future Outlook, Luciana Alt, Vitor Moura
National Cave and Karst Management Symposia
No abstract provided.
Potential Application Of Hugelkultur To Increase Water Holding Capacity Of Karst Rocky Desertified Land, Megan Laffoon, Albert Meier, Chris Groves
Potential Application Of Hugelkultur To Increase Water Holding Capacity Of Karst Rocky Desertified Land, Megan Laffoon, Albert Meier, Chris Groves
National Cave and Karst Management Symposia
No abstract provided.
The Cost Of Karst Subsidence And Sinkhole Collapse In The United States Compared With Other Natural Hazards, David J. Weary
The Cost Of Karst Subsidence And Sinkhole Collapse In The United States Compared With Other Natural Hazards, David J. Weary
Sinkhole Conference 2015
Rocks with potential for karst formation are found in all 50 states. Damage due to karst subsidence and sinkhole collapse is a natural hazard of national scope. Repair of damage to buildings, highways, and other infrastructure represents a significant national cost. Sparse and incomplete data show that the average cost of karst-related damages in the United States over the last 15 years is estimated to be at least $300,000,000 per year and the actual total is probably much higher. This estimate is lower than the estimated annual costs for other natural hazards; flooding, hurricanes and cyclonic storms, tornadoes, landslides, earthquakes, …
Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea
Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea
Sinkhole Conference 2015
Much of the Driftless Area of southeastern Minnesota is underlain by karstified carbonate bedrock. Land use in this karst terrain is dominated by agriculture, including row crop and dairy operations. The karst in this region is often mantled with up to 15 m of soil and unconsolidated sediments. As a result, underlying karst hazards such as incipient sinkholes are often hidden until they are suddenly revealed by the collapse of subsurface voids. Regionally, the economics of the dairy industry is causing a trend toward the consolidation and expansion of existing operations. As concentrated animal feeding operations (CAFO) or feedlots expand, …
Monitoring The Threat Of Sinkhole Formation Under A Portion Of Us 18 In Cerro Gordo County, Iowa Using Tdr Measurements, Kevin O'Connor, Matthew Trainum
Monitoring The Threat Of Sinkhole Formation Under A Portion Of Us 18 In Cerro Gordo County, Iowa Using Tdr Measurements, Kevin O'Connor, Matthew Trainum
Sinkhole Conference 2015
Sinkhole formation is a common occurrence in northeast Iowa, and U.S. 18 in Cerro Gordo County was constructed over an area where sinkhole formation had only been locally known. It had not been recorded or identified in the Iowa DNR database at the time. Since 2004, sinkholes have developed along the right of way. Geophysical surveys contributed very little in the identifying the cause. However a Soil Survey (drilling program) identified numerous voids within carbonate bedrock. The soil borings indicated that shale overlying the carbonate rock has been removed/eroded, and resulted in the development of a karst subsurface through the …
Evaluation Of Veterinary Pharmaceuticals And Iodine For Use As A Groundwater Tracer In Hydrologic Investigation Of Contamination Related To Dairy Cattle Operations, Larry Boot Pierce, Honglin Shi
Evaluation Of Veterinary Pharmaceuticals And Iodine For Use As A Groundwater Tracer In Hydrologic Investigation Of Contamination Related To Dairy Cattle Operations, Larry Boot Pierce, Honglin Shi
Sinkhole Conference 2015
Standard groundwater tracers such as Rhodamine WT, Fluorescein, Eosin and Tinopal CBX effectively provide a snapshot of hydrological conditions over a brief period of time and in a tightly controlled setting. However, in complex environmental situations with multiple potential sources, groundwater hydrologists are often seeking groundwater tracers that have extended longevity in the natural environment and the ability to directly pinpoint source locations. After reviewing operations of the nearby dairy it was determined that emerging contaminants, specifically two bovine veterinary pharmaceuticals (antibiotics), cephapirin sodium (CEPNa) and cephapirin benzathine (CEPB), and a sanitation agent, elemental Iodine (I) may have potential as …
Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee
Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee
Sinkhole Conference 2015
Regression analysis is used to identify monotonic trends to assign water age using ion data from two large well water databases from southeast Minnesota (SE MN). Nitrate (NO3-N), chloride (Cl), sodium (Na), and sulfate (SO4) ions in the commonly used aquifers in SE MN can be used as groundwater tracers since they are either entirely or partly anthropogenic in their sources, their loading occurs on a regional scale, and they are almost entirely conserved. Ion concentrations over time are used to establish six trend patterns. Two patterns are unchanging (background and stable above background), and four are changing (linear up, …
Recharge Area Of Selected Large Springs In The Ozarks, Bill Duley, Cecil Boswell, Jerry Prewett
Recharge Area Of Selected Large Springs In The Ozarks, Bill Duley, Cecil Boswell, Jerry Prewett
Sinkhole Conference 2015
Ongoing work by the Missouri Geological Survey (MGS) is refining the known recharge areas of a number of major springs in the Ozarks. Among the springs being investigated are: Mammoth Spring (Fulton County, Arkansas), and the following Missouri springs: Greer Spring (Oregon County), Blue Spring (Ozark County), Blue/Morgan Spring Complex (Oregon County), Boze Mill Spring (Oregon County), two different Big Springs (Carter and Douglas County) and Rainbow/North Fork/Hodgson Mill Spring Complex (Ozark County). Previously unpublished findings of the MGS and United States Geological Survey (USGS) are also being used to better define recharge areas of Greer Spring, Big Spring (Carter …
Mitigating The Risk Of Extreme Water Scarcity And Dependency: The Case Of Jordan, Joep F. Schyns, Arwa Hamaideh, Arjen Y. Hoekstra, Mesfin Mekonnen, Marlou Schyns
Mitigating The Risk Of Extreme Water Scarcity And Dependency: The Case Of Jordan, Joep F. Schyns, Arwa Hamaideh, Arjen Y. Hoekstra, Mesfin Mekonnen, Marlou Schyns
Daugherty Water for Food Global Institute: Faculty Publications
Jordan faces great internal water scarcity and pollution, conflict over trans-boundary waters, and strong dependency on external water resources through trade. This paper analyzes these issues and subsequently reviews options to reduce the risk of extreme water scarcity and dependency. Based on estimates of water footprint, water availability, and virtual water trade, we find that groundwater consumption is nearly double the groundwater availability, water pollution aggravates blue water scarcity, and Jordan’s external virtual water import dependency is 86%. The review of response options yields 10 ingredients for a strategy for Jordan to mitigate the risks of extreme water scarcity and …
Interannual And Subdecadal Variability In The Nutrient Geochemistry Of The Cariaco Basin, Mary I. Scranton, Gordon T. Taylor, Robert Thunell, Claudia R. Benitez-Nelson, Frank Muller-Karger, Kent Fanning, Laura Lorenzoni, Enrique Montes, Ramon Varela, Yrene Astor
Interannual And Subdecadal Variability In The Nutrient Geochemistry Of The Cariaco Basin, Mary I. Scranton, Gordon T. Taylor, Robert Thunell, Claudia R. Benitez-Nelson, Frank Muller-Karger, Kent Fanning, Laura Lorenzoni, Enrique Montes, Ramon Varela, Yrene Astor
Faculty Publications
The CARIACO Ocean Time Series program has made monthly measurements of oxygen, nutrients, and carbon system parameters (∑CO2, alkalinity, pH) in the Cariaco Basin since 1996. At the same time, sediment traps have collected settling particles at four to five depths ranging from 150 to 1,200 m. The depth of the transition from oxic to anoxic conditions has fluctuated dramatically over the time series due to changes in the occurrence of Caribbean water intrusions into the deep basin. Nutrient concentrations in the deep basin have increased steadily with time in a proportion reflective of the elemental ratios in the settling …
Long-Term Manure Amendments Reduced Soil Aggregate Stability Via Redistribution Of The Glomalin-Related Soil Protein In Macroaggregates, Hongtu Xie, Jianwei Li, Bin Zhang, Lianfeng Wang, Jingkuan Wang, Hongbo He, Xudong Zhang
Long-Term Manure Amendments Reduced Soil Aggregate Stability Via Redistribution Of The Glomalin-Related Soil Protein In Macroaggregates, Hongtu Xie, Jianwei Li, Bin Zhang, Lianfeng Wang, Jingkuan Wang, Hongbo He, Xudong Zhang
Agricultural and Environmental Sciences Faculty Research
Glomalin-related soil protein (GRSP) contributes to the formation and maintenance of soil aggregates, it is however remains unclear whether long-term intensive manure amendments alter soil aggregates stability and whether GRSP regulates these changes. Based on a three-decade long fertilization experiment in northeast China, this study examined the impact of long-term manure input on soil organic carbon (SOC), total and easily extractable GRSP (GRSPt and GRSPe) and their respective allocations in four soil aggregates (>2000 μm; 2000–250 μm; 250–53 μm; and <53 μm). The treatments include no fertilization (CK), low and high manure amendment (M1, M2), chemical nitrogen, phosphorus and potassium fertilizers (NPK) and combined manure and chemical fertilizers (NPKM1, NPKM2). Though SOC, GRSPe and GRSPt in soil and SOC in each aggregate generally increased with increasing manure input, GRSPt and GRSPe in each aggregate showed varying changes with manure input. Both GRSP in macroaggregates (2000–250 μm) were significantly higher under low manure input, a pattern consistent with changes in soil aggregate stability. Constituting 38~49% of soil mass, macroaggregates likely contributed to the nonlinear changes of aggregate stability under manure amendments. The regulatory process of GRSP allocations in soil aggregates has important implications for manure management under intensive agriculture.