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Landscape/Atmosphere Interactions And Carbon-Dioxide Dynamics In The Great Onyx Groundwater Basin, Mammoth Cave National Park, Kentucky, Meghan Raines
Landscape/Atmosphere Interactions And Carbon-Dioxide Dynamics In The Great Onyx Groundwater Basin, Mammoth Cave National Park, Kentucky, Meghan Raines
Masters Theses & Specialist Projects
An increase in atmospheric CO2 since the Industrial Revolution has altered rates of global climate change and has motivated a need to better quantify the flux of carbon between Earth’s reservoirs. Attempts to quantify the exchange of atmospheric carbon between sources and sinks have led to an increasing interest in the terrestrial landscape, including the continental carbon sink associated with carbonate-mineral dissolution. This research sought to better inform an understanding of karst landscapes and their relationship with global climate change through carbon cycling. The study utilized high-resolution data collection of pH, temperature, and specific conductance of waters in the Cascade …
Unroofing History Of The Northwestern Ethiopian Plateau: Insights From Low-Temperature Apatite Thermochronology, Shelby Bowden
Unroofing History Of The Northwestern Ethiopian Plateau: Insights From Low-Temperature Apatite Thermochronology, Shelby Bowden
Masters Theses & Specialist Projects
The geology of Ethiopia is dominated by the Ethiopian Plateau that is similar in elevation to, but aerially larger than, the Colorado Plateau. Several rivers have incised through the plateau, creating gorges that reach up to 1.5 km in depth. The plateau uplifted to its current elevation and was subsequently incised sometime after the Oligocene flood basalt event that signaled the arrival of the African Superplume below Kenya and Ethiopia. Due to its size and extent, published climate modeling has indicated that Late Cenozoic plateau formation could have been a driving force in the East African Cenozoic climate changes. Although …
Carbon Flux And Weathering Processes In Icelandic Glacial-Fed Rivers, Allison Quiroga
Carbon Flux And Weathering Processes In Icelandic Glacial-Fed Rivers, Allison Quiroga
Masters Theses & Specialist Projects
An investigation into the carbon dynamics and weathering processes occurring in Icelandic glacial-fed streams was conducted during the spring to summer seasonal transition in June of 2017. Four major outlet rives were sampled from the glaciers of Gígjökull, Steinsholtsjökull, Sólheimajökull, and Falljökull. Markarfljót, the major river that Gígjökull, Steinsholtsjökull, and many other glaciers drain into, was also sampled. Longitudinal sampling occurred at all sites to capture downstream trends in the hydrogeochemistry and carbon dynamics. Distinct differences in geochemistry between glacier surface meltwater, sub-glacial waters, pro-glacial lake water, and post-mixed downstream samples were evident in the data. Glacier surface streams were …
Carbon Cycling Dynamics Inferred From Carbon Isotope Sourcing In A Mid-Latitude Karst-Influenced River, Kegan N. Mcclanahan
Carbon Cycling Dynamics Inferred From Carbon Isotope Sourcing In A Mid-Latitude Karst-Influenced River, Kegan N. Mcclanahan
Masters Theses & Specialist Projects
As ever-increasing levels of carbon dioxide alter the chemistry of the Earth’s atmosphere, understanding the global carbon cycle becomes increasingly important. A particularly important component is the riverine carbon cycle, as rivers are the primary conduits for dissolved inorganic carbon from terrestrial watersheds to ocean basins. Stable carbon isotopes (13C/12C) were collected weekly and input into the mixing model IsoSource to delineate seasonal carbon sourcing along two nested basins in the upper Green River System, Kentucky. In the more siliciclastic upstream catchment, dissolved inorganic carbon (DIC) was primarily derived from soil respiration (34%). Groundwater dissolving carbonate bedrock and carbonate dissolution/precipitation …
Sources Of Co2 Controlling The Carbonate Chemistry Of The Logsdon River, Mammoth Cave, Kentucky, Bruce Elliott Hatcher
Sources Of Co2 Controlling The Carbonate Chemistry Of The Logsdon River, Mammoth Cave, Kentucky, Bruce Elliott Hatcher
Masters Theses & Specialist Projects
Logsdon River is a major, base-level stream within the Turnhole Bend Drainage basin of the Mammoth Cave System. The Logsdon River system has provided a unique opportunity to examine the geochemical evolution of a stream flowing through a major karst conduit that can be traversed for 10 km. This study examines CO2 inputs at the upstream portion of the river, which provide major control for the river’s hydrochemistry. Samples were collected from the upstream portion of Logsdon River at what is referred to as the S-188 sump and also nearby at Crowbar Dome over the course of 44 weeks …
Late Holocene Paleoenvironmental Reconstruction In Barbados, Gilman Reno Ouellette
Late Holocene Paleoenvironmental Reconstruction In Barbados, Gilman Reno Ouellette
Masters Theses & Specialist Projects
Barbados is the easternmost island in the Caribbean region, and is uniquely situated between the Atlantic Ocean and Caribbean Sea. Being an isolated island with a karstified aquifer providing the majority of the nation’s water resources, Barbados has found itself in water scarce situations in recent years. In order to better understand natural shifts in groundwater recharge (which is determined by shifts in precipitation), longer records of precipitation are needed than are available from modern measurements. This study presents a paleoclimate reconstruction for the late Holocene on Barbados using stable and radiogenic isotope ratios in speleothem lamina as proxies. In …