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dc.contributor.advisorMurgulet, Dorina
dc.contributor.advisorMurgulet, Dorina
dc.contributor.authorLopez, Cody Vaughn
dc.contributor.authorLopez, Cody Vaughn
dc.date.accessioned2020-04-18T02:44:29Z
dc.date.accessioned2020-04-18T02:44:29Z
dc.date.available2020-04-18T02:44:29Z
dc.date.available2020-04-18T02:44:29Z
dc.date.issued2018-12
dc.date.issued2018-12
dc.identifier.urihttps://hdl.handle.net/1969.6/87821
dc.identifier.urihttps://hdl.handle.net/1969.6/87821
dc.description.abstractThis study evaluates the role of submarine groundwater discharge (SGD)-derived nutrients to Baffin Bay, a semi-arid, hypersaline bay in south Texas. SGD can be equivalent to riverine input in some places, making SGD’s role in nutrient input important. Dissolved inorganic nitrogen (DIN), and total alkalinity combined with SGD measurements, using two different geochemical tracers (radium-226 [226Ra], radium 224 [224Ra] and radon [222Rn]) and geophysical investigations were conducted. SGD rates were found to have slight spatial variation with higher rates near the shoreline around areas characterized by course-grained sediments and relic serpulid reefs. The222Rn and 226Ra-based SGD estimates produced agreeable results, within the range of uncertainties, and no significant changes in SGD from July to November, within the same year, were observed. However, 226Ra and 224Ra activities decreased from July to November and are associated with large decreases in porewater DIN concentrations. July and November 222Rn-derived SGD rates were 31.4±32.7 and 30.0±30.9 cm∙d-1, respectively while those derived from 226Ra were 16.6±1.7 and 13.2±1.3 cm∙d-1, respectively. Given the lack of change in SGD between the two seasons, organic matter (OM) decay may be the driving force for changes in radium activities as it can lead to reducing conditions that enhance radium solubility from sediments. In addition to OM remineralization from phytoplankton, a shift from a seawater to a terrestrial groundwater source in the subterranean estuary is also likely to be responsible for the larger porewater radium activities and nutrient concentrations in July. A comparison of bay-wide solute fluxes indicates that DIN inputs, mainly in the form of ammonium (NH4+), are almost five orders of magnitude higher in the SGD component than the surface runoff. Therefore, regardless of the magnitude of SGD and its nature (i.e. fresh or saline; groundwater or recirculated saline), the associated nutrient input is likely significant in this shallow bay system in warmer months. This study helps provide an understanding of the possible effects of OM decay on radium and DIN fluctuations and inputs in a hypersaline estuary. Studying these relationships is important as hypersalinity is a developing problem in freshwater-limited environments.en_US
dc.format.extent98 pagesen_US
dc.language.isoen_USen_US
dc.rightsAttribution-ShareAlike 3.0 United States*
dc.rightsThis material is made available for use in research, teaching, and private study, pursuant to U.S. Copyright law. The user assumes full responsibility for any use of the materials, including but not limited to, infringement of copyright and publication rights of reproduced materials. Any materials used should be fully credited with its source. All rights are reserved and retained regardless of current or future development or laws that may apply to fair use standards. Permission for publication of this material, in part or in full, must be secured with the author and/or publisher.en_US
dc.rights.urihttp://creativecommons.org/licenses/by-sa/3.0/us/*
dc.subjectammoniumen_US
dc.subjectGroundwateren_US
dc.subjectporewateren_US
dc.subjectradiumen_US
dc.subjectradonen_US
dc.subjectSGDen_US
dc.titleSubmarine groundwater discharge and nutrient input to a semiarid and hypersaline estuary: Baffin Bay, Texasen_US
dc.typeTexten_US
thesis.degree.disciplineEnvironmental Scienceen_US
thesis.degree.grantorTexas A & M University--Corpus Christien_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Scienceen_US
dc.contributor.committeeMemberFelix, Joseph
dc.contributor.committeeMemberHu, Xinping
dc.contributor.committeeMemberFelix, Joseph
dc.contributor.committeeMemberHu, Xinping
dc.description.departmentPhysical and Environmental Sciencesen_US
dc.description.collegeCollege of Science and Engineeringen_US
dc.type.genreThesisen_US


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Attribution-ShareAlike 3.0 United States
Except where otherwise noted, this item's license is described as Attribution-ShareAlike 3.0 United States