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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Hydrogeology of the Tapeats Amphitheater and Deer Basin, Grand Canyon, Arizona: a study in karst hydrology.

Huntoon, Peter W. January 1968 (has links) (PDF)
Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1968. / Includes bibliographical references (leaves 123-124).
2

Simulation modeling of karst aquifer conduit evolution and relations to climate /

Broome, John. January 2008 (has links)
Thesis (M.S.)--Western Kentucky University, 2008. / Includes bibliographical references (leaves 39-40 ).
3

Origin and morphology of notches in carbonate cliffs and hillslopes implications for paleoclimate and paleohydrology /

Reece, Matthew A. January 2004 (has links)
Thesis (M.S.)--Mississippi State University. Department of Geosciences. / Title from title screen. Includes bibliographical references.
4

Epikarst Hydrogeochemical Changes in Telogenetic Karst Systems in South-central Kentucky

Jackson, Leah 01 July 2017 (has links)
Telogenetic epikarst carbon sourcing and transport processes and the associated hydrogeochemical responses are often complex and dynamic. Among the processes involved in epikarst development is a highly variable storage and flow relationship that is often influenced by the type, rate, and amount of dissolution kinetics involved. Diffusion rates of CO2 in the epikarst zone may drive hydrogeochemical changes that influence carbonate dissolution processes and conduit formation. Most epikarst examinations of these defining factors ignore regional-scale investigations in favor of characterizing more localized processes. This study aims to address that discrepancy through a comparative analysis of two telogenetic epikarst systems under various land uses to delineate regional epikarst behavior characteristics and mechanisms that influence carbon flux and dissolution processes in south-central Kentucky. High-resolution hydrogeochemical and discharge data from multiple data loggers and collected water samples serve to provide a more holistic picture of the processes at work within these epikarst aquifers, which are estimated to contribute significantly to carbonate rock dissolution processes and storage of recharging groundwater reservoirs on the scale of regional aquifer rates. Data indicate that, in agricultural settings, long-term variability is governed by seasonal availability of CO2, while in urban environments extensive impermeable surfaces trap CO2 in the soil, governing increased dissolution and conduit development in a heterogonous sense, which is often observed in eogenetic karst development, as opposed to bedding plane derived hydraulic conductivity usually observed in telogenetic settings. These results suggest unique, site-specific responses, despite regional geologic similarities. Further, the results suggest the necessity for additional comparative analyses between agricultural settings and urban landscapes, as well as a focus on carbon sourcing in urban environments, where increased urban sprawl could influence karst development
5

Regional hydrology captured in northern Borneo rainwater and dripwater isotope variability

Moerman, Jessica 08 June 2015 (has links)
Oxygen and hydrogen isotopes (δ18O, δD) are increasingly powerful tools for reconstructing past hydroclimate variability. The utility of δ18O- and δD-based paleoclimate records, however, depends on our understanding of how well these tracers reflect past climate conditions. The dynamics controlling the relationship between climate and water isotope variability are highly complex and often poorly constrained, especially in the tropics, where many key high-resolution paleoclimate records rely on past rainfall isotopes as proxies for hydroclimate. In this dissertation, I use multi-year timeseries of daily rainfall and biweekly dripwater δ18O from northern Borneo – a site for stalagmite δ18O-based paleoclimate reconstruction in the heart of the West Pacific Warm Pool – to track the cloud-to-calcite transformation of δ18O and its relationship to large-scale climate variability. Chapter 2 investigates the variability of rainfall δ18O variability from northern Borneo on diurnal to interannual timescales and its relationship with local and regional climate. Chapter 3 investigates the rainfall-to-dripwater transformation of climate-related isotopic signals following water transit through the Borneo cave system. Overall, this dissertation provides empirical support for the interpretation of northern Borneo stalagmite δ18O as a robust indicator of regional-scale hydroclimate variability, where higher δ18O reflects regional drying. More generally, this research provides a roadmap for obtaining more nuanced interpretations of speleothem δ18O records from multi-year, high-resolution, paired timeseries of rainfall and dripwater δ18O.
6

Examining the Spatial and Temporal Variations in CO<em>2</em> Partial Pressure in the Deep Vadose Zone Above Jinapsan Cave, Guam

Regis, Jamar 21 March 2019 (has links)
Carbon dioxide is the primary driver of dissolution and precipitation reactions in epigene limestone caves. While much work has been conducted on CO2 dynamics involved in dissolution in the phreatic zone, less research has been conducted on vadose CO2 dynamics, especially in tropical caves developed in eogenetic limestones. In this study, we investigate spatial and temporal variation in pCO2 in the deep vadose zone of eogenetic limestone above Jinapsan Cave, located in northern Guam. Five years of carbonate chemistry data from three dripwater sites in Jinapsan Cave (Flatman, Station1, and Trinity) were used to model the theoretical pCO2 with which infiltrating waters had likely equilibrated along flow paths between the soil and the cave. Theoretical pCO2 essentially models the amount of CO2 that would need to be added to dripwaters that have degassed and become supersaturated with respect to calcite upon entering a lower CO2 cave void in order to return the water to equilibrium. Theoretical pCO2 values range from 10-2.8 to 10-1.8 atm among the three sites examined. These results were generally lower compared to similar studies in telogenetic and continental karst, which range from 10-3.7 to 10-0.96 atm. Theoretical pCO2 data from Jinapsan Cave have significant differences among the three drip sites, with the site closest to the entrance (Flatman) having the highest values and the farthest from the entrance (Trinity) having the lowest values; in addition, the values also have a great seasonal variability. Low theoretical pCO2 values in Jinapsan Cave’s dripwaters indicate that vadose zones in eogenetic limestone may be better ventilated, and hence have lower pCO2, than those in telogenetic limestone. The ventilation of the vadose zone is facilitated by high matrix porosity and permeability of eogenetic limestone and may be driven by barometric pressure changes or wind.
7

Structural and Lithological Influences on the Tony Grove Alpine Karst System, Bear River Range, North Central Utah

Bahr, Kirsten 01 May 2016 (has links)
The fracture-dominated Tony Grove alpine karst system in the Bear River Range in north-central Utah, has caves ranging from 5m deep, consisting of solution-enlarged single fractures, to the large, 374m deep, Main Drain Cave, characterized by a series of vertical drops and horizontal passages. The caves int he Tony Grove area are developed throughout the 510m thick Fish Haven and Laketown Dolomites. The Swan Peak Formation, consisting of orthoquartzite and shale, underlies the dolomites. Surface fracture measurements (n=3502) yielded two distinctive sets of fractures. The northeast-southwest sets had a mean orientation of 41±0.7° and the northwest-southeast set with a mean of 133±5°. Of the sixteen caves surveyed for fractures and passages, fifteen were controlled by fractures, although some caves had both facture-and non-fracture-controlled passages. Only one cave was entirely non-fracture controlled, likely due to a change in lithology. Main Drain Cave, the only cave with long horizontal passages, was surveyed for both fracture and stratigraphic influences on horizontal cave development. Results indicate some sections are controlled by southeast-trending-fractures and other sections are controlled by southwest-dipping-bedding planes. Alternatively, parts of the down-dip-oriented sections may be influenced by southwest-oriented fractures. Stratigraphic control in this cave includes cherty layers that appear to hinder down-cutting of passages into lower stratigraphic units. Surface mapping determined that there is a southeast-oriented fold pair east of the Logan Peak Syncline, consisting of the Naomi Peak Syncline and the Cottonwood Canyon Anticline. The anticline merges with the Logan Peak Syncline near the head of Cottonwood Canyon. The Naomi Peak Syncline continues north-northeast through the Tony Grove area and may divert water from the Tony Grove area to Wood Camp Hollow Spring in Logan Canyon. The anticline acts as a divide between groundwater traveling southwest to Dewitt Spring and south-southeast to Wood Camp Hollow Spring. The Swan Peak Formation appears to act as a barrier to groundwater movement into the underlying formations, separating the Tony Grove system from underlying systems.
8

Fate and Transport of E. coli Through Appalachian Karst Systems

Schmidt, Diana Felice 17 July 2023 (has links)
Karst waters serve as important water sources in rural Appalachia and are well-connected to surface waters, making them susceptible to anthropogenic contamination, including by fecal indicator bacteria which represent a public health risk. This work designed and implemented a watershed-scale monitoring program for a 26 km2 sinking stream system in southwest Virginia to determine the fate and transport of E. coli in the system. This hydrologically complex watershed is predominantly agricultural and includes multiple key surface water sinks that enter Smokehole Cave and emerge at Smokehole Spring. Field campaigns at surface sites and within Smokehole Cave included bacteriological sampling, hydrologic measurement, and dye tracing. Field data was synthesized to: 1) examine variations in E. coli concentrations in the watershed during varying flows/seasonal conditions; and 2) calculate E. coli growth/decay coefficients for the karst system during different flow/antecedent conditions. E. coli concentrations at Smokehole Spring consistently peaked days after peak hydrologic stage. Flow conditions and storm event response were the largest drivers of E. coli transport through the system. Dye trace results revealed that water from sinks can be stored or move slowly through the karst system, resurging during storm events. E. coli was calculated to decay within the karst system, with a half-life of about 5-120 days which is longer than the travel time of water through the cave of approximately 0.5-2 days. Findings indicate that E. coli transport in Appalachian karst systems is hydrologically driven, roadside spring water collection is not recommended, and bacterial treatment is encouraged if performed. Targeted land-management practices should be explored to decrease E. coli loadings in karst waters. / Master of Science / Karst (cave) waters serve as important water sources in rural Appalachia and are well-connected to surface waters, making them susceptible to contamination from human or animal waste – a public health risk. A field monitoring program was conducted in an agriculturally impacted stream and cave system in southwest Virginia to determine how E. coli, a bacteria found in the waste of humans and other animals, moves through the system. There are several places where surface water sinks into the cave system, eventually entering Smokehole Cave and emerging at Smokehole Spring. Field data collection was performed at surface sites and within Smokehole Cave including sampling for E. coli, water flow measurements, and dye tracing. Field data was combined to 1) examine variations in E. coli concentrations during varying flows/seasonal conditions and 2) calculate E. coli growth/decay coefficients for the cave system during different flow and soil moisture conditions. It was found that E. coli concentrations at Smokehole Spring consistently peaked days after the water depth. Flow conditions and storm events were the largest drivers in E. coli movement through the system. Dye trace results revealed that water from sinks can be stored or moves slowly through the cave system and resurges during storm events. E. coli was found to decay within the cave system. Findings indicate that E. coli movement in Appalachian cave systems is driven by storm events, roadside spring water collection is not recommended, and bacteria treatment is recommended if performed. Cave-specific land-management practices are recommended to keep E. coli from entering cave waters.
9

Speleothems as environmental recorders : A study of Holocene speleothems and their growth environments in Sweden

Sundqvist, Hanna S. January 2007 (has links)
<p>The main aim of this thesis was to contribute with detailed information of regional environmental change during the Holocene through studies of speleothems and their growth environments from two caves, Korallgrottan and Labyrintgrottan in northwestern Sweden, and a cellar vault in Uppsala. This was done through studies of stable isotopes and luminescence properties in the speleothems in combination with a detailed monitoring study in Korallgrottan.</p><p>The monitoring study suggests that stalagmites fed by stalactites with slow and stable drip rates from deep inside the cave may be suitable as palaeoclimate archives. Similarities between oxygen isotope signals of contemporary samples from Labyrintgrottan and Korallgrottan emphasize the potential of speleothems from Labyrintgrottan to also provide high resolution regional palaeoclimate information.</p><p>Except for a number of cold events stalagmite δ<sup>18</sup>O records from northern Scandinavia indicate that temperatures were warmer than today between 9500 and 6000 years ago. During this period the interval between 7800 and 6000 years ago seems to have been the warmest. The area above Labyrintgrottan was most likely covered by much denser vegetation than today at the time of stalagmite growth (9500-7500 years ago) and was, unlike today, probably situated below the local tree-limit between 9000 and 8000 years ago. The δ<sup>18</sup>O record of a stalagmite from Korallgrottan covering the last 4000 years agrees with the concept of a warmer period, the so called Medieval Warm Period, centred around AD1000 and a colder period, the so called Little Ice Age, somewhere between AD1000 and today.</p><p>Studies of luminescence properties in fast growing speleothems from Uppsala indicate that the variations in luminescence intensity are annual and that the annual lamiae of the luminescent record represent a flush of organic material.</p>
10

A dinâmica da drenagem subterrânea no planalto cárstico Alambari - Ouro Grosso, Iporanga (SP) / not available

Calux, Allan Silas 05 April 2019 (has links)
O carste pode ser entendido como um sistema aberto, uma forma de relevo que resulta de processos que operam em conjunto nos subsistemas hidrológico e geoquímico. Os mecanismos de gênese e desenvolvimento de aquíferos cársticos levam à formação de meios anisotrópicos altamente descontínuos e heterogêneos, na sua estrutura espacial e no seu funcionamento temporal, podendo apresentar estrutura de permeabilidade hierárquica com fluxo turbulento. Apesar das limitações impostas pela anisotropia do meio, a descarga de aquíferos cársticos tende a concentrar-se em uma única ressurgência, permitindo, para entender suas propriedades, o uso da análise de sistemas baseada em estatística de séries temporais. O arranjo espacial complexo da drenagem subterrânea tem implicações no sinal hidrológico do exutório do sistema, de forma que a correta interpretação dos espectros obtidos prescindem de uma adequada caracterização da estrutura da drenagem, por meio testes com traçadores. Neste contexto, este trabalho teve como objetivo investigar o sinal hidrológico e sua relação com os padrões de recarga e a geometria e distribuição espacial das drenagens subterrâneas dos aquíferos do planalto cárstico Alambari-Ouro Grosso, localizados na região cárstica do Vale do Ribeira, município de Iporanga, São Paulo. Os métodos e técnicas utilizados envolveram análises por meio de fotointerpretação, morfometria de depressões poligonais, identificação e tipificação in situ e em gabinete das feições de recarga e descarga do sistema, testes qualitativos e quantitativos com traçadores corantes, obtenção de séries históricas de parâmetros hidrológicos e estatística descritivas exploratórias em séries temporais. Os resultados obtidos a partir de testes com traçadores corantes e análises morfométricas demonstraram a existência, no mesmo sinclinal, de dois sistemas independentes e funcionalmente distintos: i) Sistema Alambari, responsável por drenar quase 80% da área das depressões poligonais do planalto e a maior área da contribuição alóctone aos sistemas (65,9%), apresentando assinaturas hidrológicas típicas de um carste bem desenvolvido; e ii) Ouro Grosso, composta por depressões poligonais menos expressivas, recargas difusas, armazenamento epicárstico/pedológico e comportamento mais inercial. O sistema Alambari apresenta ainda depressões poligonais com as maiores declividades e a maior amplitude altimétrica, o que representa recargas potencialmente mais energéticas que no sistema Ouro Grosso. As séries temporais demonstraram que, em qualquer estação climática, o sistema Ouro Grosso é mais inercial que o sistema Alambari e o efeito memória da vazão menos variável em Alambari, característica provavelmente associada a maior capacidade de drenagem do sistema. Comportamento semelhante ao da vazão foi observado na condutividade elétrica, com exceção no inverno de 2017 (o mais seco), onde observou-se uma subida gradativa da mesma, demonstrando que a memória da condutividade elétrica pode refletir a resposta rápida do sistema a impulsos de chuva ou o comportamento de longo prazo associado à lenta e constante mineralização das águas do sistema. O comportamento da condutividade elétrica no sistema Ouro Grosso é anômalo, uma vez que as injeções de água meteórica no sistema resultam em picos de saturação e não diluição. Este fenômeno foi explicado a partir da noção de \"efeito pistão\", ou seja, um impulsionamento de águas saturadas na rede fraturada e nos reservatórios epicársticos/pedológicos, resultando na disponibilização de água mineralizada ao sistema. A análise das correlações cruzadas mostrou que na relação chuva versus condutividade elétrica, nos períodos relativamente mais secos, a desmineralização da água é menor. As análises também evidenciaram o comportamento dos reservatórios dinâmicos cujo fluxo de água mineralizada aumenta quando a recarga é mais intensa. / Karsts can be understood as an open system, a form of relief resulting from processes that operate together in the hydrological and geochemical subsystems. The mechanisms of genesis and development of karst aquifers lead to the formation of highly discontinuous and heterogeneous anisotropic media, in their spatial structure and in their temporal functioning, being able to present a hierarchical permeability structure with turbulent flow. Despite the limitations imposed by the environmental anisotropy, the discharge of karst aquifers tends to concentrate in a single resurgence, allowing, to understand its properties, the use of systems analysis based on time series statistics. The complex spatial arrangement of the underground drainage has implications in the hydrological signal of the exudate of the system, so that the correct interpretation of the obtained spectra doesn\'t have an adequate characterization of the structure of the drainage, through tests with tracers. In this context, the objective of this work was to investigate the hydrological sign and its relation with the recharge patterns and the geometry and spatial distribution of the subterranean drainage of the aquifer of the Alambari-Ouro Grosso karst plateau, located in the karst region of the Ribeira Valley, southeastern Brazil. The methods and techniques used involved analysis through photointerpretation, morphometry of polygonal depressions, in situ identification and typing, and in the recharge and discharge characteristics of the system, qualitative and quantitative tests with dye tracers, obtaining historical series of hydrological parameters and descriptive statistics in time series. The results obtained from tests with dye tracers and morphometric analysis showed the existence, in the same syncline, of two independent and functionally distinct systems: i) Alambari System, responsible for draining almost 80% of the area of the polygonal depressions of the plateau and the largest area of the allochthonous contribution to the systems (65.9%), presenting hydrological signatures typical of a well developed karst; and ii) Ouro Grosso, composed of less expressive polygonal depressions, diffuse refills, epikarst/pedological storage and more inertial behavior. The Alambari system also has polygonal depressions with the highest slopes and the highest altimetric amplitude, which represents potentially more energetic recharges than in the Ouro Grosso system. The time series showed that, in any weather season, the Ouro Grosso system is more inertial than Alambari system and the flow memory effect is less variable in Alambari, a characteristic probably associated to the greater drainage capacity of the system. Similar behavior to the flow rate was observed in the electrical conductivity, except in the winter of 2017 (the driest), where it was observed a gradual increase, demonstrating that the electrical conductivity memory can reflect the rapid response of the system to impulses of rainfall or the long-term behavior associated with the slow and steady mineralization of the system\'s waters. The behavior of the electrical conductivity in the Ouro Grosso system is anomalous, since the injections of meteoric water into the system result in saturation and non-dilution peaks. This phenomenon was explained by the notion of \"piston effect\", a saturated water propulsion in the fractured network and in the epikarst/pedological reservoirs, resulting in the availability of mineralized water to the system. The analysis of the cross correlations showed that in the relationship between rainfall versus electrical conductivity, in the relatively drier periods, water demineralization is lower. The analyzes also showed the behavior of the dynamic reservoirs whose mineralized water flow increases when the recharge is more intense.

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