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Carbon Storage Via Mineral Bonding In Subsoils A Review Of Soil Processes, Kiele Goins Jul 2021

Carbon Storage Via Mineral Bonding In Subsoils A Review Of Soil Processes, Kiele Goins

Theses and Dissertations

Soil is an important but often poorly understood portion of the carbon cycle. Soil can store more carbon than twice today’s atmosphere, but the factors that control carbon storage are often unclear. Carbon enters the soil through input of organic matter, erosion, and aerosol deposition and is lost mostly via microbial decomposition. Carbon loss in soil is impacted by the chemical composition of organic compounds, environmental factors, and human activities. Furthermore, as climate changes soil, carbon storage may be vulnerable. Although carbon can be stored throughout soil, carbon storage varies with depth. In topsoil, carbon is stored for short periods …


Groundwater Flow And Transport At The Forest-Marsh Boundary: A Modeling Study, Sophia Chason Sanders Jul 2021

Groundwater Flow And Transport At The Forest-Marsh Boundary: A Modeling Study, Sophia Chason Sanders

Theses and Dissertations

The forest-marsh boundary, where tidally influenced salt marshes meet a forested upland, is hydrologically complex due to its multiple water inputs. Groundwater flow and salinity transport at this boundary are not well understood. In order to make predictions about salinity at this boundary as it responds to climatic factors, a two-dimensional model was built to simulate groundwater flow and solute transport at a salt marsh on Sapelo Island, Georgia. After calibration based on observed data from wells at the study site, the model can be used to identify patterns in groundwater movement and solute transport that may influence the vegetation …


Groundwater Discharge From Passive Continental Margins: Rethinking Marine Chemical Budgets, Andrew William Osborne Jul 2021

Groundwater Discharge From Passive Continental Margins: Rethinking Marine Chemical Budgets, Andrew William Osborne

Theses and Dissertations

Geothermal convection and sediment compaction drive large-scale flow in continental shelves. We suggest that this flow is an overlooked control on the major ion chemistry of the ocean. Conventional ocean chemical budgets are constructed using river discharge, axial mid-ocean ridge (MOR) convection and CaCO3 production, but these budgets are still poorly quantified. We synthesized data from 17 passive continental margin basins to calculate a range of estimated groundwater and chemical fluxes from continental shelves, considering five major ions (Ca2+, Na+, K+, Mg2+, and Cl-). When extrapolated globally, volumetric groundwater flux estimates were comparable to those for MOR axial circulation, and …


Radium At The Lost City And Mid-Cayman Rise Hydrothermal Fields, Jessica D. Frankle Apr 2021

Radium At The Lost City And Mid-Cayman Rise Hydrothermal Fields, Jessica D. Frankle

Theses and Dissertations

Fluid residence times of deep-sea hydrothermal circulation influence chemical cycling in the ocean. While fluid residence time estimates exist for many basalt-hosted systems, no estimates exist for serpentinite hosted systems that emit fluids with inherently different chemistry. We measured short- and long-lived radium (Ra) nuclides in fluids from two hydrothermal systems on the Mid-Cayman Rise to constrain their residence times: the Von Damm Vent Field, a mixed ultramafic-mafic system, and the Piccard Vent Field, a mafic, neovolcanic system. Von Damm fluids contain remarkably elevated 223Ra activities (half-life = 11.4 days), surpassing those from basalt-hosted hydrothermal systems by one to two …


Monitoring Of Carbon Dioxide Injection In The Southeastern United States, Adil Murad Awad Alshammari Apr 2021

Monitoring Of Carbon Dioxide Injection In The Southeastern United States, Adil Murad Awad Alshammari

Theses and Dissertations

Over the past few decades, measured levels of atmospheric carbon dioxide have substantially increased. One way to limit the adverse impacts of increased carbon dioxide concentrations is to capture and store it inside Earth's subsurface, a process known as CO2 sequestration. This method's success is critically dependent on the ability to confine injected CO2 for up to thousands of years. Establishing effective maintenance of sealing systems of reservoirs is of importance to prevent CO2 leakage. Understanding the nature and rate of potential CO2 leakage related to this injection process is essential to evaluating seal effectiveness and ultimately mitigating global warming. …


Carbonatite Metasomatism And Water Systematics Of Peridotite Xenoliths From Lanzarote, Canaries, Sierra N. Patterson Apr 2021

Carbonatite Metasomatism And Water Systematics Of Peridotite Xenoliths From Lanzarote, Canaries, Sierra N. Patterson

Theses and Dissertations

Water in Earth’s mantle, present as structurally bound hydrogen in minerals, influences large scale processes like mantle deformation, plate tectonics, and melting. To better understand the processes controlling water concentrations in the Earth’s upper mantle, we analyzed hydrogen (calculated as ppm wt. H2O), major, and trace element concentrations in minerals from peridotite mantle xenoliths of Lanzarote, Canaries. The Canaries Islands are thought to be the surface expression of a deep-seated mantle plume erupting through the Atlantic Ocean lithosphere. Carbonatite magmas have erupted in the Canaries and previous studies have shown evidence for carbonatite metasomatism in Lanzarote peridotites. Thus, …