Earth Sciences Commons^™

An Operational Overview Of The Export Processes In The Ocean From Remote Sensing (Exports) Northeast Pacific Field Deployment, David A. Siegel, Ivona Cetinic, Jason R. Graff, Craig M. Lee, Norman Nelson, Mary Jane Perry, Inia Soto Ramos, Deborah K. Steinberg, Ken Buesseler, Roberta Hamme, Andrea J. Fassbender, David Nicholson, Melissa M. Omand, Marie Robert, Andrew Thompson, Vinicius Amaral, Michael Behrenfeld, Claudia R. Benitez-Nelson, Kelsey Bisson, Emmanuel Boss, Et. Al.

Faculty Publications

The goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean Station Papa in the Northeast Pacific Ocean during summer of 2018, providing context for other papers in this special collection. The experiment was conducted with …

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 …

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

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 …

Concentrations, Ratios, And Sinking Fluxes Of Major Bioelements At Ocean Station Papa, Montserrat Roca-Martí

Faculty Publications

Fluxes of major bioelements associated with sinking particles were quantified in late summer 2018 as part of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign near Ocean Station Papa in the subarctic northeast Pacific. The thorium-234 method was used in conjunction with size-fractionated (1–5, 5–51, and >51 μm) concentrations of particulate nitrogen (PN), total particulate phosphorus (TPP), biogenic silica (bSi), and particulate inorganic carbon (PIC) collected using large volume filtration via in situ pumps. We build upon recent work quantifying POC fluxes during EXPORTS. Similar remineralization length scales were observed for both POC and PN across …

Review Of The Analysis Of 234Th In Small Volume (2–4 L) Seawater Samples: Improvements And Recommendations, Samantha J. Clevenger, Claudia Benitez-Nelson, Jessica Drysdale, Steven Pike, Viena Puigcorbé, Ken O. Buesseler

Faculty Publications

Schools may be one important context where adolescents learn and shape the behaviors necessary for promoting global inclusivity in adulthood. Given the importance of bystanders in halting bullying and peer aggression, the focus of this study is on both moral judgments regarding one type of bullying, social exclusion, and factors that are associated with bystander intervention. The study includes 896 adolescents, who were 6th (N = 450, M_age = 11.73), and 9th (N = 446, M_age = 14.82) graders, approximately evenly divided by gender. Participants were primarily European–American (63.3%). Results revealed that girls and participants who …

Biogenic Sinking Particle Fluxes And Sediment Trap Collection Efficiency At Ocean Station Papa, Margaret Estapa, Ken Buesseler, Collen A. Durkin, Melissa Omand, Claudia Benitez-Nelson, Montserrat Rocca-Martí, Elly Breves, R. P. Kelly, Steve Pike

Faculty Publications

Comprehensive field observations characterizing the biological carbon pump (BCP) provide the foundation needed to constrain mechanistic models of downward particulate organic carbon (POC) flux in the ocean. Sediment traps were deployed three times during the EXport Processes in the Ocean from RemoTe Sensing campaign at Ocean Station Papa in August–September 2018. We propose a new method to correct sediment trap sample contamination by zooplankton “swimmers.” We consider the advantages of polyacrylamide gel collectors to constrain swimmer influence and estimate the magnitude of possible trap biases. Measured sediment trap fluxes of thorium-234 are compared to water column measurements to assess trap …

Ocean-Atmosphere Interactions During Hurricanes Marco And Laura (2020), Emily N. Eley, Bulusu Subrahmanyam, Corinne B. Trott

Faculty Publications

During August of the 2020 Atlantic Hurricane Season, the Gulf of Mexico (GoM) was affected by two subsequent storms, Hurricanes Marco and Laura. Hurricane Marco entered the GoM first (22 August) and was briefly promoted to a Category 1 storm. Hurricane Laura followed Marco closely (25 August) and attained Category 4 status after a period of rapid intensification. Typically, hurricanes do not form this close together; this study aims to explain the existence of both hurricanes through the analysis of air-sea fluxes, local thermodynamics, and upper-level circulation. The GoM and its quality of warm, high ocean heat content waters proved …

De Novo Transcriptome Assembly Of The Green Alga Ankistrodesmus Falcatus, Rachel A. Schomaker, Jeffry L. Dudycha

Faculty Publications

Ankistrodesmus falcatus is a globally distributed freshwater chlorophyte that is a candidate for biofuel production, is used to study the effects of toxins on aquatic communities, and is used as food in zooplankton research. Each of these research fields is transitioning to genomic tools. We created a reference transcriptome for of A. falcatus using NextGen sequencing and de novo assembly methods including Trinity, Velvet-Oases, and EvidentialGene. The assembled transcriptome has a total of 17,997 contigs, an N50 value of 2,462, and a GC content of 64.8%. BUSCO analysis recovered 83.3% of total chlorophyte BUSCOs and 82.5% of the eukaryotic …

The Impact Of Aquaculture On The Genetics And Distribution Of The Onuphid Annelid Diopatra Biscayensis, Matthew P. Galaska, David S. Wethey, Andrés Arias, Stanislas F. Dubois, Kenneth M. Halanych, Sarah A. Woodin

Faculty Publications

Aim

Evolutionary history of natural populations can be confounded by human intervention such as the case of decorator worm species Diopatra (Onuphidae), which have a history of being transported through anthropogenic activities. Because they build tubes and act as ecosystem engineers, they can have a large impact on the overall ecosystem in which they occur. One conspicuous member, Diopatra biscayensis, which was only described in 2012, has a fragmented distribution that includes the Bay of Biscay and the Normanno-Breton Gulf in the English Channel. This study explores the origin of these worms in the Normanno-Breton region, which has been …

The Malina Oceanographic Expedition: How Do Changes In Ice Cover, Permafrost And Uv Radiation Impact Biodiversity And Biogeochemical Fluxes In The Arctic Ocean?, Philippe Massicotte, Rainer M.W. Amon, Antoine David, Sergio Balzano, Simon Bélanger, Ronald Benner, Dominique Boeuf, Annick Bricaud, Flavienne Bruyant, Gwenaëlle Chaillou, Malik Chami, Bruno Charrière, Jing Chen, Hervé Claustre, Pierre Coupel, Nicole Delsaut, David Doxaran, Jens Ehn, Cédric Fichot, Marie-Hélène Forget, Et. Al.

Faculty Publications

The MALINA oceanographic campaign was conducted during summer 2009 to investigate the carbon stocks and the processes controlling the carbon fluxes in the Mackenzie River estuary and the Beaufort Sea. During the campaign, an extensive suite of physical, chemical and biological variables were measured across seven shelf-basin transects (south-north) to capture the meridional gradient between the estuary and the open ocean. Key variables such as temperature, absolute salinity, radiance, irradiance, nutrient concentrations, chlorophyll a concentration, bacteria, phytoplankton and zooplankton abundance and taxonomy, and carbon stocks and fluxes were routinely measured onboard the Canadian research icebreaker CCGS Amundsen and from a …

Extensive Decentralized Hydrogen Export From The Atlantis Massif, Susan Q. Lang, Marvin D. Lilley, Tamara Baumberger, Gretchen L. Früh-Green, Sharon L. Walker, William J. Brazelton, Debroah S. Kelley, Mitchell Elend, David A. Butterfield, Aaron J. Mau

Faculty Publications

Hydrogen is an important energy source for subsurface microbial communities, but its availability beyond the flow focused through hydrothermal chimneys is largely unknown. We report the widespread export of H₂ across the Atlantis Massif oceanic core complex (30°N, Mid-Atlantic Ridge; up to 44 nM), which is distinct from the circulation system feeding the Lost City Hydrothermal Field (LCHF) on the massif's southern wall. Methane (CH₄) abundances are generally low to undetectable (<3 nM) in fluids that are not derived from the LCHF. Reducing fluids exit the seafloor over a wide geographical area and depth …

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

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. …

Surface Freshwater Fluxes In The Arctic And Subarctic Seas During Contrasting Years Of High And Low Summer Sea Ice Extent, Sarah B. Hall, Bulusu Subrahmanyam, Ebenezer S. Nyadjro, Annette Samuelsen

Faculty Publications

Freshwater (FW) flux between the Arctic Ocean and adjacent waterways, predominantly driven by wind and oceanic currents, influences halocline stability and annual sea ice variability which further impacts global circulation and climate. The Arctic recently experienced anomalous years of high and low sea ice extent in the summers of 2013/2014 and 2012/2016, respectively. Here we investigate the interannual variability of oceanic surface FW flux in relation to spatial and temporal variability in sea ice concentration (SIC), sea surface salinity (SSS), and sea surface temperature (SST), focusing on years with summer sea–ice extremes. Our analysis between 2010–2018 illustrate high parameter variability, …

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, …

Volcaniclastic Sandstones Record The Influence Of Subducted Pacific Morb On Magmatism At The Early Izu-Bonin Arc, Anders Mccarthy, Gene M. Yogodzinski, Michael Bizimis, Ivan P. Savov, Rosemary Hickey-Vargas, Richard Arculus, Osamu Ishizuka

Faculty Publications

The remnant rear-arc segment of the early Izu-Bonin arc, known as the Kyushu-Palau Ridge (KPR), is a key location where magmatic outputs can be constrained during the lifetime of an island arc. We present new geochemical data for coarse-grained basaltic to andesitic volcaniclastic sandstones derived from the KPR and deposited in the Amami Sankaku Basin (IODP Site U1438, Unit III rocks) in the time period 40-30 Ma. Bulk disaggregated and cleaned volcaniclastic sandstones of Unit III at Site U1438 retain primary magmatic signatures and can be used to infer the evolution of magmatic sources of the juvenile Izu-Bonin island arc …

Cost Effectiveness Of Community Led Total Sanitation In Ethiopia And Ghana, Jonny Crocker, David Fuente, Jamie Bartram

Faculty Publications

We conducted cost effectiveness analyses of four different CLTS interventions implemented in Ethiopia and Ghana. In each country, a pilot approach in which additional local actors were trained in CLTS facilitation was compared to the conventional approach. Data were collected using bottom-up costing, household surveys, and observations. We assessed variability of cost effectiveness from a societal perspective for latrine ownership and latrine use outcomes in different contexts. Cost effectiveness ranged from $34–$1897 per household ($5.85–$563 per person) gaining access to a private latrine or stopping open defecation, depending on the intervention, context, and outcome considered. For three out of four …

Particulate And Dissolved Organic Matter In Stormwater Runoff Influences Oxygen Demand In Urbanized Headwater Catchments, Kelly M. Mccabe, Erik M. Smith, Susan Q. Lang, Claudia Benitez-Nelson

Faculty Publications

Increasing inputs of organic matter (OM) are driving declining dissolved oxygen (DO) concentrations in coastal ecosystems worldwide. The quantity, source, and composition of OM transported to coastal ecosystems via stormwater runoff have been altered by land use changes associated with urbanization and subsequent hydrologic flows that accompany urban stormwater management. To elucidate the role of stormwater in the decline of coastal DO, rain event sampling of biochemical oxygen demand (BOD) in samples collected from the outfall of stormwater ponds and wetlands, as well as samples of largely untreated runoff carried by stormwater ditches, was conducted across a range of urban …

Model And Data, Equilibrium Of Self-Formed, Single-Thread, Sand-Bed Rivers, Enrica Viparelli, Esther C. Eke

Faculty Publications

This submission contains the following files, also uploaded as Supplementary Information for the manuscript Equilibrium of self-formed, single-thread, sand-bed rivers submitted after major revisions to the AGU journal Geophysical Research Letters.

Excel file with embedded macro Equilibrium_calculator.xlxm, contains the solver of the analytical model presented in the manuscript.

Excel file Equilibrium_results.xlxs contains model data used to generate the plots.

The Impact Of The Madden–Julian Oscillation On Cyclone Amphan (2020) And Southwest Monsoon Onset, Heather L. Roman-Stork, Subrahmanyam Bulusu

Faculty Publications

Cyclone Amphan was an exceptionally strong tropical cyclone in the Bay of Bengal that achieved a minimum central pressure of 907 mb during its active period in May 2020. In this study, we analyzed the oceanic and surface atmospheric conditions leading up to cyclogenesis, the impact of this storm on the Bay of Bengal, and how the processes that led to cyclogenesis, such as the Madden–Julian Oscillation (MJO) and Amphan itself, in turn impacted southwest monsoon preconditioning and onset. To accomplish this, we took a multiparameter approach using a combination of near real time satellite observations, ocean model forecasts, and …

Extensive Morphological Variability In Asexually Produced Planktic Foraminifera, Catherine V. Davis, Caitlin M. Livsey, Hannah M. Palmer, Pincelli M. Hull, Ellen Thomas, Tessa M. Hill, Claudia R. Benitez-Nelson

Faculty Publications

Marine protists are integral to the structure and function of pelagic ecosystems and marine carbon cycling, with rhizarian biomass alone accounting for more than half of all mesozooplankton in the oligotrophic oceans. Yet, understanding how their environment shapes diversity within species and across taxa is limited by a paucity of observations of heritability and life history. Here, we present observations of asexual reproduction, morphologic plasticity, and ontogeny in the planktic foraminifer in laboratory culture. Our results demonstrate that planktic foraminifera reproduce both sexually and asexually and demonstrate extensive phenotypic plasticity in response to nonheritable factors. These two processes fundamentally explain …

Multi-Attribute Analysis Using Coherency And Ant-Tracking Techniques For Fault And Fracture Detection In La Florida Anticline, Llanos Foothills, Colombia, Ziyad Albesher, James N. Kellogg, Ibraheem Hafiza, Essam Saeid

Faculty Publications

We present techniques to reduce noise and enhance seismic quality, making possible the first multi-attribute analysis of a 3D seismic volume in the Llanos Foothills (La Florida anticline) of Colombia using coherency and ant-tracking techniques for fault and fracture detection. The results could help reduce risk in models of reservoir fracture porosity and permeability. The dominant fracture strike direction in the studied seismic volume (La Florida anticline) is NE–SW (055 ± 20°), parallel to the structural strike of the adjacent Eastern Cordillera Foothills. The application of the ant-tracking technique also reveals the NE-SW fracture set for the reservoir rocks in …

Feel The Vibration! Measuring The Ground Motion Caused By Racecars At The Zmax Dragway, Gabrielle Herrin

Senior Theses

Dragsters raced down a 1,000 ft track at the zMAX Dragway and the resulting ground motion was recorded, analyzed, and displayed live to fans. At the NGK Spark Plugs NHRA Four-Wide Nationals on April 26 – 28, 2019 and the NTK NHRA Carolina Nationals on October 11-13, 2019 the ground motion was recorded with novel devices anchored on the track walls. The devices were fit with Raspberry Pis, precise clocks, and accelerometers recording at 400 samples per second. In April, the geometry of the devices was located near the start line and in October, devices were anchored to the outside …

Genomic Evidence For Formate Metabolism By As The Key To Unlocking Deep Carbon In Lost City Microbial Ecosystems, Julia M. Mcgonigle, Susan Q. Lang, William J. Brazelton

Faculty Publications

The Lost City hydrothermal field on the Mid-Atlantic Ridge supports dense microbial life on the lofty calcium carbonate chimney structures. The vent field is fueled by chemical reactions between the ultramafic rock under the chimneys and ambient seawater. These serpentinization reactions provide reducing power (as hydrogen gas) and organic compounds that can serve as microbial food; the most abundant of these are methane and formate. Previous studies have characterized the interior of the chimneys as a single-species biofilm inhabited by the Lost City , but they also indicated that this methanogen is unable to metabolize formate. The new metagenomic results …

Green Edge Ice Camp Campaigns: Understanding The Processes Controlling The Under-Ice Arctic Phytoplankton Spring Bloom, Philippe Massicotte, Rémi Amiraux, Marie-Pier Amyot, Philippe Archambault, Mathieu Ardyna, Laurent Arnaud, Lise Artigue, Cyril Aubry, Pierre Ayotte, Guislain Bécu, Simon Bélanger, Ronald Benner, Henry C. Bittig, Annick Bricaud, Éric Brossier, Flavienne Bruyant, Et. Al.

Faculty Publications

The Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797∘ N, 63.7895∘ W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea-ice cover from the surface to the bottom (at 360 m depth) to better understand the factors driving the …

Habitability Of The Oceanic Alkaline Serpentinite Subsurface: A Case Study Of The Lost City Hydrothermal Field, Susan Q. Lang, William J. Brazelton

Faculty Publications

The Lost City hydrothermal field is a dramatic example of the biological potential of serpentinization. Microbial life is prevalent throughout the Lost City chimneys, powered by the hydrogen gas and organic molecules produced by serpentinization and its associated geochemical reactions. Microbial life in the serpentinite subsurface below the Lost City chimneys, however, is unlikely to be as dense or active. The marine serpentinite subsurface poses serious challenges for microbial activity, including low porosities, the combination of stressors of elevated temperature, high pH and a lack of bioavailable ∑CO2. A better understanding of the biological opportunities and challenges in serpentinizing systems …

Green Forest Businesses As A Method To Improve Communities In Unesco’S East Usambara Biosphere Reserve In Tanzania, Myoung Su Ko

Theses and Dissertations

A number of developing countries, especially those in Africa which have experienced former colonization, are still struggling with exploitation of their natural resources. Throughout the development of environmental management, the strategy of natural resource management has evolved from mistreating the environment for economic and social development, to separating human activities from the environment for extreme environmental protection, to ensuring the interaction between human life and environment for sustainable development. Although an abundance of natural resources, and particularly forests, exist in the protected areas, the residents in communities surrounding protected areas are usually economically and socially poor.

With this situation, the …

3-D Potential Field Inversion Camp Clubhouse Crossroads Mafic Intrusive Pluton, Coastal Plain, South Carolina, Kubra Sibel Albayrak

Theses and Dissertations

The Central Atlantic Magmatic Province (CAMP) at the Triassic-Jurassic boundary, is the largest known igneous province in the world. However, the geometry and volume of CAMP intrusives under the Coastal Plain of the southeastern United States are poorly known. Under the Coastal Plain sediments of Georgia and South Carolina, the “J” seismic reflector was predicted to be produced by a CAMP lava flow. Recent studies of seismic and well data have shown that the “J” reflector is an unconformity and only locally a CAMP lava flow. In the Clubhouse Crossroads area of South Carolina, seismic reflection, seismic refraction, and well …

Glacial-Interglacial Changes In The Thermocline Structure Of The Makassar Strait: Implications For Changes In The Indonesian Throughflow, Michael Lis

Theses and Dissertations

The Indo-Pacific Warm Pool exerts a strong influence on the global climate system because it partially controls heat and moisture exchange (pressure gradient) between the atmosphere and ocean, and thus, the intensity of the Indonesian throughflow (ITF) via the Makassar Strait, the main passage of water connecting the Pacific and Indian Oceans. The magnitude of ITF is reflected by the structure of the oceanic thermocline. Here, we use shell δ¹⁸O signatures and trace element composition of foraminifera (Globigerinoides ruber, Pulleniatina obliquiloculata, and Globigerinoides menardii) in two sediment records spanning the past 30 kya collected from …