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Articles 3121 - 3150 of 13989

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Long-Term African Dust Delivery To The Eastern Atlantic Ocean From The Sahara And Sahel Regions: Evidence From Quaternary Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Kathleen R. Simmons, Matthew C. Baddock, Juan F. Betancourt, Alejandro Lomoschitz Jan 2021

Long-Term African Dust Delivery To The Eastern Atlantic Ocean From The Sahara And Sahel Regions: Evidence From Quaternary Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Kathleen R. Simmons, Matthew C. Baddock, Juan F. Betancourt, Alejandro Lomoschitz

United States Geological Survey: Staff Publications

Africa is the most important source of dust in the world today and dust storms from that continent frequently deposit sediment on the nearby Canary Islands. Many investigators have inferred African dust inputs to Canary Islands paleosols based only on the presence of quartz. However, some local rocks do contain this mineral, so quartz alone is insufficient proof of dust deposition. Further, it is not known whether the Sahara Desert or the Sahel region is more important as a dust source. We address these issues by study of sequences of Pleistocene aeolian sands on the islands of Lanzarote and Fuerteventura. …


Eolian Sediments, Daniel R. Muhs Jan 2021

Eolian Sediments, Daniel R. Muhs

United States Geological Survey: Staff Publications

Eolian (windblown) sediments form some of the world’s most dramatic landscapes and comprise important parts of the geologic record. This article reviews the characteristics, origins, and significance of eolian deposits, including windblown sand, silt, and dust.

Landforms composed of eolian sand, either as dunes or sand sheets, occupy substantial areas over the surface of the Earth (perhaps as much as 6% globally, but over ~20% of the world’s arid zones, according to Pye and Tsoar, 2009). Low-latitude arid or semiarid regions, usually under the influence of subtropical high-pressure cells, are some of the largest areas of eolian sand accumulation (Lancaster, …


Ecology Of An Isolated Muskrat Population During Regional Population Declines, Laken S. Ganoe, Matthew J. Lovallo, Justin D. Brown, W. David Walter Jan 2021

Ecology Of An Isolated Muskrat Population During Regional Population Declines, Laken S. Ganoe, Matthew J. Lovallo, Justin D. Brown, W. David Walter

United States Geological Survey: Staff Publications

Evidence indicating a decline in Ondatra zibethicus (Muskrat) populations in the United States during the past 40 years has led to speculation regarding factors influencing Muskrat survival. In order to understand population dynamics and survival, it is important to first define the ecology of local populations. We investigated the dwelling structure use, movements, home range, and survival of radio-tagged Muskrats (n = 14) in an urban wetland complex in central Pennsylvania. We used locations collected from intensive radio-telemetry monitoring to determine number of lodging structures used, hourly movement, and size and percent area overlap of home ranges. Muskrats shared …


Quantifying Model Structural Uncertainty Using Airborne Electromagnetic Data, Burke J. Minsley, Nathan Leon Foks, Paul A. Bedrosian Jan 2021

Quantifying Model Structural Uncertainty Using Airborne Electromagnetic Data, Burke J. Minsley, Nathan Leon Foks, Paul A. Bedrosian

United States Geological Survey: Staff Publications

The ability to quantify structural uncertainty in geological models that incorporate geophysical data is affected by two primary sources of uncertainty: geophysical parameter uncertainty and uncertainty in the relationship between geophysical parameters and geological properties of interest. Here, we introduce an open-source, trans-dimensional Bayesian Markov chain Monte Carlo (McMC) algorithm GeoBIPy—Geophysical Bayesian Inference in Python—for robust uncertainty analysis of time-domain or frequency-domain airborne electromagnetic (AEM) data. The McMC algorithm provides a robust assessment of geophysical parameter uncertainty using a trans-dimensional approach that lets the AEM data inform the level of model complexity necessary by allowing the number of model layers …


Elemental And Radionuclide Exposures And Uptakes By Small Rodents, Invertebrates, And Vegetation At Active And Post-Production Uranium Mines In The Grand Canyon Watershed, Danielle Cleveland, Jo Ellen Hinck, Julia S. Lankton Jan 2021

Elemental And Radionuclide Exposures And Uptakes By Small Rodents, Invertebrates, And Vegetation At Active And Post-Production Uranium Mines In The Grand Canyon Watershed, Danielle Cleveland, Jo Ellen Hinck, Julia S. Lankton

United States Geological Survey: Staff Publications

The effects of breccia pipe uranium mining in the Grand Canyon watershed (Arizona) on ecological and cultural resources are largely unknown. We characterized the exposure of biota to uranium and cooccurring ore body elements during active ore production and at a site where ore production had recently concluded. Our results indicate that biota have taken up uranium and other elements (e.g., arsenic, cadmium, copper, molybdenum, uranium) from exposure to ore and surficial contamination, like blowing dust. Results indicate the potential for prolonged exposure to elements and radionuclides upon conclusion of active ore production. Mean radium-226 in deer mice was up …


Life In Hampton Roads Survey Press Release #7: Perceptions Of Flooding, Hurricane Evacuation, & Sheltering During Covid-19, Social Science Research Center, Old Dominion University Jan 2021

Life In Hampton Roads Survey Press Release #7: Perceptions Of Flooding, Hurricane Evacuation, & Sheltering During Covid-19, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

Life in Hampton Roads 2021 - Flooding, Hurricane Evacuation, & Sheltering During COVID-19

The changing climate and rising sea levels touch nearly every aspect of life in Hampton Roads, with some neighborhoods and communities experiencing it more acutely. But, overall, how persistent is recurrent flooding as perceived by Hampton Roads residents? This year’s survey finds that nearly 23% of respondents state that recurrent flooding is a problem in their neighborhood, a number broadly consistent with the responses seen since this question was first asked in 2013 when 23% of respondents also indicated that recurrent flooding was a problem in their …


Odu Professors Study Gulf Stream Decline, News @ Odu Jan 2021

Odu Professors Study Gulf Stream Decline, News @ Odu

News Items

No abstract provided.


Comparing Interrelated Stress Measures To Differentiate Acute And Chronic Stress In Urban Freshwater Turtles, Katherine Caldwell Jan 2021

Comparing Interrelated Stress Measures To Differentiate Acute And Chronic Stress In Urban Freshwater Turtles, Katherine Caldwell

Honors Program Theses

As urban areas grow in size and number, there are increasing impacts on the wildlife. While some species adapt, others cannot thrive in these conditions. Stress is the biological response to a stimulus that threatens homeostasis, which can be used to understand the condition of an individual. While acute stress is beneficial for survival, chronic stress can lead to deleterious impacts. A majority of turtles can be classified as declining in number or endangered, yet there is little understanding of their physiological stress response. This study examined how various stress measures—including corticosterone (CORT) in plasma, nails and leeches, metabolic measures, …


Unexpected Role Of Communities Colonizing Dead Coral Substrate In The Calcification Of Coral Reefs, Manoela Romanó De Orte, David A. Koweek, Tyler Cyronak, Yuichiro Takeshita, Alyssa Griffin, Kennedy Wolfe, Alina Szmant, Robert Whitehead, Rebecca Albright, Ken Caldeira Jan 2021

Unexpected Role Of Communities Colonizing Dead Coral Substrate In The Calcification Of Coral Reefs, Manoela Romanó De Orte, David A. Koweek, Tyler Cyronak, Yuichiro Takeshita, Alyssa Griffin, Kennedy Wolfe, Alina Szmant, Robert Whitehead, Rebecca Albright, Ken Caldeira

Marine & Environmental Sciences Faculty Articles

Global and local anthropogenic stressors such as climate change, acidification, overfishing, and pollution are expected to shift the benthic community composition of coral reefs from dominance by calcifying organisms to dominance by non-calcifying algae. These changes could reduce the ability of coral reef ecosystems to maintain positive net calcium carbonate accretion. However, relationships between community composition and calcification rates remain unclear. We performed field experiments to quantify the metabolic rates of the two most dominant coral reef substrate types, live coral and dead coral substrate colonized by a mixed algal assemblage, using a novel underwater respirometer. Our results revealed that …


Great South Bay, Long Island, New York Summer Phytoplankton Identification & Monitoring Program, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli Jan 2021

Great South Bay, Long Island, New York Summer Phytoplankton Identification & Monitoring Program, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli

CERCOM Reports

Phytoplankton Collection Methodologies: 80 micron Plankton Tow Net with sample bottle attachment

Phytoplankton Protocol: 1.Gather Samples 2.Make one slide per sample 3.View slides using microscope connected with computer 4. Record findings using “ Row # “ and “ Colum letter “ 5. Record using “ Tally’s “ per species found within sample 6. Capture anything interesting “ Take Picture “ 7.Duplicate pictures taken 8.Make sure measurement of species found is taken 9. Email Jennifer Maucher at [email protected] , include pictures, questions and names of the species you “guess” you found.


Carbon Dioxide And Particulate Matter Concentration On Hampton Roads Air Quality, Gregory Hubbard Jan 2021

Carbon Dioxide And Particulate Matter Concentration On Hampton Roads Air Quality, Gregory Hubbard

OUR Journal: ODU Undergraduate Research Journal

Hampton Roads has been a maritime crossroads for the last 400 years. Industrialization has impacted the coastal region for the last 250 years. The expansion of the Port of Virginia in 2019 has created dense traffic in the region resulting in impacts to air quality. Two waste products that affect humans are particulate matter and carbon dioxide. Both respective emissions can cause adverse effects on humans, such as asthma, some lung cancers, and other respiratory distress. Scientists and health practitioners are studying the effects of particulate matter on human health. Hampton Roads, in particular, because of its unique location on …


Lift In The Vertical Shear Of Southerly Jet Embedded In A Uniform Westerly Flow, Qi Hu, George Limpert Jan 2021

Lift In The Vertical Shear Of Southerly Jet Embedded In A Uniform Westerly Flow, Qi Hu, George Limpert

Department of Earth and Atmospheric Sciences: Faculty Publications

A new mechanism is proposed as a potential cause for the one-third of warm season severe nocturnal convection in the U.S. Great Plains that develops in environments without the presence of air mass boundaries of fronts or mesoscale systems. This mechanism is tested in two- and three dimensional models. Results show strong ascent (~1.0 m/s) sufficient for nocturnal convection initiation, arising from interactions of mean westerly zonal wind with the vertical shear of a northern vortex and also perturbation westerly winds that are created by the Coriolis torque on the Great Plains southerly low-level jet. The interaction involving the northern …


The 3H/3He Groundwater Age-Dating Method And Applications, Troy E. Gilmore, Mikaela L. Cherry, Didier Gastmans, Douglas Kip Solomon, Eric Christopher Humphrey Jan 2021

The 3H/3He Groundwater Age-Dating Method And Applications, Troy E. Gilmore, Mikaela L. Cherry, Didier Gastmans, Douglas Kip Solomon, Eric Christopher Humphrey

School of Natural Resources: Faculty Publications

Groundwater age-dating is an important tool for quantifying and managing water resources. Groundwater age is the elapsed time between recharge (at the land surface or water table) and the time when groundwater is sampled. If groundwater is sampled at the point of discharge from an aquifer, then the age represents the groundwater transit time. Groundwater that has recharged in recent decades is considered young groundwater. In many areas, the quality and quantity of young groundwater has been impacted by human activities and groundwater age-dating is useful for quantifying current and historical water and contaminant fluxes into and through aquifers. This …


Aviation Human-In-The-Loop Simulation: Best Practices For Subjective Performance Measurement, John Kleber, Beth Blickensderfer Jan 2021

Aviation Human-In-The-Loop Simulation: Best Practices For Subjective Performance Measurement, John Kleber, Beth Blickensderfer

Aviation Weather Training Research

Subjective performance measurements are a useful tool for researchers and instructors to evaluate tasks that are difficult to quantify with objective data pulled from a simulator or the physiological data of pilots. Subjective performance measurements are non-intrusive measures typically conducted by human raters. Some recommendations for utilizing subjective measures include reducing the workload of the human raters, concealing the aim of the experiment from participants, utilizing multiple raters to evaluate each participant, providing raters with proper training, developing error-resistant rater forms and, including both subjective and objective measures when possible.


New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign – Seafloor Photographs, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy Jan 2021

New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign – Seafloor Photographs, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy

Data Catalog

The "New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign – Seafloor Photographs” was developed by the University of New Hampshire (UNH) Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC). The field campaign was conducted to provide ground truth for surficial geology maps for the continental shelf off New Hampshire (NH) and focused on the inner shelf between the coast and the Isles of Shoals. Station locations were chosen where high-resolution bathymetry was available, including multibeam echosounder (MBES) surveys conducted by the UNH CCOM/JHC Hydrographic Field Course (Ocean Engineering 972), MBES surveys by the NOAA National Ocean Service (NOS), …


A Model-Based Exploratory Study Of Sulfur Dioxide Dispersions From Concentrated Animal Feeding Operations In The Southeastern United States, Jesse Winchester, Rezaul Mahmood, William Rodgers, Philip J. Silva, Nanh Lovanh, Joshua D. Durkee, John Loughrin Jan 2021

A Model-Based Exploratory Study Of Sulfur Dioxide Dispersions From Concentrated Animal Feeding Operations In The Southeastern United States, Jesse Winchester, Rezaul Mahmood, William Rodgers, Philip J. Silva, Nanh Lovanh, Joshua D. Durkee, John Loughrin

High Plains Regional Climate Center: Staff Publications

In the Southeastern U. S. there are Concentrated Animal Feeding Operations (CAFOs) that emit a variety of gases, including SO2. Sulfur is emitted as reduced sulfur compounds and can react in the atmosphere to produce SO2. It is expected that the concentra­tion and spread of SO2 emissions from these sources would differ between wet and dry periods. In this research, SO2 emissions from locations representing CAFOs and its dispersion over the south­eastern U.S. were simulated through sensitivity experiments using the Weather Research and Forecasting-Chemistry (WRF- Chem) model. Simulations were performed for dry periods and …


New Hampshire Continental Shelf Geophysical Database: 2012-2013 Newbex Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Zachary S. Mcavoy, Rachel C. Morrison Jan 2021

New Hampshire Continental Shelf Geophysical Database: 2012-2013 Newbex Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Zachary S. Mcavoy, Rachel C. Morrison

Data Catalog

An approximately 4.5 km transect running from lower Portsmouth Harbor seaward onto the inner continental shelf was established to serve as the field site for the Newcastle Backscatter Experiment (NEWBEX). Acoustic backscatter measurements were made along the transect to examine relationships between backscatter and seafloor properties. This transect takes advantage of the diversity and heterogeneity of bottom types in lower Portsmouth Harbor and approach. In support of NEWBEX, a field campaign was undertaken to describe the sedimentologic characteristics of the seafloor along the transect. A total of five cruises were carried out approximately seasonally on November 26, 2012 and June …


New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign – Seafloor And Sample Photographs And Sediment Data, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy Jan 2021

New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign – Seafloor And Sample Photographs And Sediment Data, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy

Data Catalog

The "New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign - Seafloor and Sample Photographs and Sediment Data " contains photographs of the seafloor from sampling locations, photographs of the sediment samples, and grain size data from a major field campaign conducted in 2016- 2017 and from the UNH Ocean Engineering 972 Hydrographic Field Course classes in 2012, 2014, and 2018. In total, sixteen one-day cruises provided 150 samples for grain size analysis. The database provides complete descriptions for each sample including identification, station and sample characteristics, sediment classifications, grain size statistics, and grain size distribution. Presented here are tables …


Resolving Variability In Size Structure In An Individual-Based Model For The North Pacific Krill, Euphausia Pacifica, Roxanne Robertson Jan 2021

Resolving Variability In Size Structure In An Individual-Based Model For The North Pacific Krill, Euphausia Pacifica, Roxanne Robertson

Cal Poly Humboldt theses and projects

Individual-based models (IBMs) have emerged as a powerful tool for ecological research and are particularly well suited to studies of plankton ecology. In this thesis, I develop an IBM for the North Pacific krill, Euphausia pacifica, with the goal of replicating observed variability in size-structure in the northern California Current Ecosystem. Krill, and E. pacifica in particular, are central to the structure and function of the California Current Ecosystem. Their response to environmental forcing translates climate variability to higher trophic levels and underpins broader ecosystem responses. Recent observations indicate environmental and climate-related shifts in E. pacifica size distributions, which …


Mapping Michigan's Historic Coastlines, Ryan A. Williams Jan 2021

Mapping Michigan's Historic Coastlines, Ryan A. Williams

Dissertations, Master's Theses and Master's Reports

This five-year project, sponsored by the Michigan Department of Environment, Great Lakes, and Energy, is working to map how Michigan’s Great Lakes shorelines have changed over the past 80+ years. Products of this project include publicly available digital, georeferenced, historic aerial photography datasets, as well as map layers depicting the locations of historic shorelines and bluff lines from 1938, 1980, 2009, 2016, 2018, and 2020. Additional products include bluff retreat risk areas, shoreline rate of change map layers, and tools to assist in the development of future Coastal Vulnerability Index projects for the Great Lakes. All products are available as …


The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes Jan 2021

The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes

Honors Theses

The internal recycling phosphorus in freshwater lake bottom sediments represents a significant source of hypolimnetic phosphorus (P) release for many of Maine’s lakes. In summer months, Maine lakes often thermally stratify and the lake hypolimnion develops anoxia, leading to a reduction in redox potential at the sediment-water interface. These reducing conditions facilitate the reductive dissolution of ferric iron, and, since phosphorus is often present in freshwater lake sediments as solid FeOOH-PO4 complexes, results in release of soluble phosphorus into the water column. Our current study presents field and laboratory data from sediment fractionation extractions designed to quantify concentrations of …


Central Equatorial Pacific Cooling During The Last Glacial Maximum, Minda Moriah Monteagudo, Jean Lynch-Stieglitz, Thomas M. Marchitto, Matthew W. Schmidt Jan 2021

Central Equatorial Pacific Cooling During The Last Glacial Maximum, Minda Moriah Monteagudo, Jean Lynch-Stieglitz, Thomas M. Marchitto, Matthew W. Schmidt

OES Faculty Publications

Establishing tropical sea surface temperature (SST) during the Last Glacial Maximum (LGM) is important for constraining equilibrium climate sensitivity to radiative forcing. Until now, there has been little data from the central equatorial Pacific in global compilations, with foraminiferal assemblage‐based estimates suggesting the region was within 1°C of modern temperatures during the LGM. This is in stark contrast to multi‐proxy evidence from the eastern and western Pacific and model simulations which support larger cooling. Here we present the first estimates of glacial SST in the central equatorial Pacific from Mg/Ca in Globigerinoides ruber. Our results show that the central Pacific …


Bioactive Trace Metals And Their Isotopes As Paleoproductivity Proxies: An Assessment Using Geotraces-Era Data, T. J. Horner, S. H. Little, T. W. Conway, J. R. Farmer, Jennifer E. Hertzberg, D. J. Janssen, A.J.M. Lough, J.L. Mckay, A. Tessin, S.J.G. Galer, S. L. Jaccard, F. Lacan, A. Paytan, K. Wuttig, Geotraces-Pages Biological Productivity Working Group Members Jan 2021

Bioactive Trace Metals And Their Isotopes As Paleoproductivity Proxies: An Assessment Using Geotraces-Era Data, T. J. Horner, S. H. Little, T. W. Conway, J. R. Farmer, Jennifer E. Hertzberg, D. J. Janssen, A.J.M. Lough, J.L. Mckay, A. Tessin, S.J.G. Galer, S. L. Jaccard, F. Lacan, A. Paytan, K. Wuttig, Geotraces-Pages Biological Productivity Working Group Members

OES Faculty Publications

Phytoplankton productivity and export sequester climatically significant quantities of atmospheric carbon dioxide as particulate organic carbon through a suite of processes termed the biological pump. Constraining how the biological pump operated in the past is important for understanding past atmospheric carbon dioxide concentrations and Earth's climate history. However, reconstructing the history of the biological pump requires proxies. Due to their intimate association with biological processes, several bioactive trace metals and their isotopes are potential proxies for past phytoplankton productivity, including iron, zinc, copper, cadmium, molybdenum, barium, nickel, chromium, and silver. Here, we review the oceanic distributions, driving processes, and depositional …


Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann Jan 2021

Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann

OES Faculty Publications

Sea level in the South Atlantic Ocean has only been measured at a small number of tide-gauge locations, which causes considerable uncertainty in 20th-century sea-level trend estimates in this basin. To obtain a better-constrained sea-level trend in the South Atlantic Ocean, this study aims to answer two questions. The first question is: can we combine new observations, vertical land motion estimates, and information on spatial sampling biases to obtain a likely range of 20th-century sea-level rise in the South Atlantic? We combine existing observations with recovered observations from Dakar and a high-resolution sea-level reconstruction based on salt-marsh sediments from the …


Pore Water Exchange-Driven Inorganic Carbon Export From Intertidal Salt Marshes, Joeseph J. Tamborski, Meagan Eagle, Barret L. Kurylyk, Kevin D. Kroeger, Zhaoihui Aleck Wang, Paul Henderson, Matthew A. Charette Jan 2021

Pore Water Exchange-Driven Inorganic Carbon Export From Intertidal Salt Marshes, Joeseph J. Tamborski, Meagan Eagle, Barret L. Kurylyk, Kevin D. Kroeger, Zhaoihui Aleck Wang, Paul Henderson, Matthew A. Charette

OES Faculty Publications

Respiration in intertidal salt marshes generates dissolved inorganic carbon (DIC) that is exported to the coastal ocean by tidal exchange with the marsh platform. Understanding the link between physical drivers of water exchange and chemical flux is a key to constraining coastal wetland contributions to regional carbon budgets. The spatial and temporal (seasonal, annual) variability of marsh pore water exchange and DIC export was assessed from a microtidal salt marsh (Sage Lot Pond, Massachusetts). Spatial variability was constrained from 224Ra : 228Th disequilibria across two hydrologic units within the marsh sediments. Disequilibrium between the more soluble 224Ra …


Toward Resolving Disparate Accounts Of The Extent And Magnitude Of Nitrogen Fixation In The Eastern Tropical South Pacific Oxygen Deficient Zone, Corday R. Selden, Margaret R. Mulholland, Brittany Widner, Peter Bernhardt, Amal Jayakumar Jan 2021

Toward Resolving Disparate Accounts Of The Extent And Magnitude Of Nitrogen Fixation In The Eastern Tropical South Pacific Oxygen Deficient Zone, Corday R. Selden, Margaret R. Mulholland, Brittany Widner, Peter Bernhardt, Amal Jayakumar

OES Faculty Publications

Examination of dinitrogen (N2) fixation in the Eastern Tropical South Pacific oxygen deficient zone has raised questions about the range of diazotrophs in the deep sea and their quantitative importance as a source of new nitrogen globally. However, technical considerations in the deployment of stable isotopes in quantifying N2 fixation rates have complicated interpretation of this research. Here, we report the findings of a comprehensive survey of N2 fixation within, above and below the Eastern Tropical South Pacific oxygen deficient zone. N2 fixation rates were measured using a robust 15N tracer method (bubble removal) …


Microbially Induced Sedimentary Structures In Clastic Deposits: Implication For The Prospection For Fossil Life On Mars, Nora Noffke Jan 2021

Microbially Induced Sedimentary Structures In Clastic Deposits: Implication For The Prospection For Fossil Life On Mars, Nora Noffke

OES Faculty Publications

Abundant and well-preserved fossil microbenthos occurs in siliciclastic deposits of all Earth ages, from the early Archean to today. Studies in modern settings show how microbenthos responds to sediment dynamics by baffling and trapping, binding, biostabilization, and growth. Results of this microbial-sediment interaction are microbially induced sedimentary structures (MISS). Successful prospection for rich MISS occurrences in the terrestrial lithological record requires unraveling genesis and taphonomy of MISS, both of which are defined only by a narrow range of specific conditions. These conditions have to coincide with high detectability which is a function of outcrop quality, bedding character, and rock type. …


The Renaissance Of Odum's Outwelling Hypothesis In 'Blue Carbon' Science, Isaac R. Santos, David J. Burdige, Tim C. Jennerjahn, Steven Bouillon, Alex Cabral, Oscar Serrano, Thomas Wernberg, Karen Filbee-Dexter, Julia A. Guimond, Joseph J. Tamborski Jan 2021

The Renaissance Of Odum's Outwelling Hypothesis In 'Blue Carbon' Science, Isaac R. Santos, David J. Burdige, Tim C. Jennerjahn, Steven Bouillon, Alex Cabral, Oscar Serrano, Thomas Wernberg, Karen Filbee-Dexter, Julia A. Guimond, Joseph J. Tamborski

OES Faculty Publications

The term ‘Blue Carbon’ was coined about a decade ago to highlight the important carbon sequestration capacity of coastal vegetated ecosystems. The term has paved the way for the development of programs and policies that preserve and restore these threatened coastal ecosystems for climate change mitigation. Blue carbon research has focused on quantifying carbon stocks and burial rates in sediments or accumulating as biomass. This focus on habitat-bound carbon led us to losing sight of the mobile blue carbon fraction. Oceans, the largest active reservoir of carbon, have become somewhat of a blind spot. Multiple recent investigations have revealed high …


Larry Philip Atkinson 1941-2020, Gregory Cutter, Louis Codispoti Jan 2021

Larry Philip Atkinson 1941-2020, Gregory Cutter, Louis Codispoti

OES Faculty Publications

No abstract provided.


Artificial Reefs: A History, A Science, A Technology, Mairead D. Farrell Jan 2021

Artificial Reefs: A History, A Science, A Technology, Mairead D. Farrell

Honors Theses

Over the past 60 years, artificial reefs have expanded beyond the definition of a technology, and in turn have developed into a unique branch of marine science. To better emphasize this growth and separation, a brief history of artificial reef development and usage in chapter two shows some of the key shifts over time in this technology’s purpose and the materials used to achieve that goal. Likewise, to indicate the scientific development of artificial reefs as a branch of marine science, their usage for discovery and research is recorded in chapter three, along with the exponential increase in published scientific …