Physical Sciences and Mathematics Commons^™

Accuracy Investigation Of Gnss-Reflectometry For Sea Level Monitoring On Horseshoe Island, Antarctica: Preliminary Results Of The Turkish Permanent Gnss Station (Tur1), Mahmut Oğuz Selbesoğlu, Hasan Hakan Yavaşoğlu, Mustafa Fahri̇ Karabulut, Özgün Oktar, Vahap Engi̇n Gülal, Hi̇mmet Karaman, Mustafa Ersel Kamaşak

Turkish Journal of Earth Sciences

Antarctica is called a natural laboratory and is highly important for investigating climate change and its evolution over time. Sustainability is a critical concern due to the challenges posed by glacier melting and rising sea levels due to global warming. According to the Intergovernmental Panel on Climate Change, since the industrial age, the global mean sea level has risen by about 20 cm as a result of the increase in the average world temperature by 1 °C. Therefore, long-term observations by satellite-based techniques in and around Antarctica are of great importance for monitoring the impacts of climate change. In the …

Applicability Of Real-Time Ppp Technique In Polar Regions As An Accurate And Efficient Real-Time Positioning System, Reha Meti̇n Alkan, Serdar Erol, Bi̇lal Mutlu

Turkish Journal of Earth Sciences

The polar regions, which include the Arctic and Antarctic areas, attract the attention of people every day, and issues that are closely related to the future of humanity make these regions even more important. Accurate and reliable positioning in polar regions is very critical for scientific research projects and also for commercial, touristic, and other human activities. In this study, the usability and the accuracy performance of the real-time precise point positioning (RT-PPP) technique in high-latitude polar regions with harsh environmental and extreme atmospheric conditions were investigated. Within that framework, the GNSS dataset of six IGS multi-GNSS stations located at …

The Petrogenesis Of Analcime In The Coppermine Formation On Robert Island, South Shetland Islands, Antarctica, Rai̇f Kandemi̇r, Yilmaz Demi̇r, Cüneyt Şen, Ufuk Celal Yağcioğlu

Turkish Journal of Earth Sciences

The South Shetland Islands were shaped by island arc volcanism that occurred from the Jurassic to the Quaternary. Robert Island is located in the center of this archipelago, and Coppermine Peninsula, located on the southwestern part of Robert Island, exposures significant rock outcrops of basalts and andesitic-basaltic agglomerates of the Coppermine Formation. The investigated samples were collected during Turkish Antarctic Expedition 2 (TAE-II), in March-April 2018, from the area northeast of Triplet Hill. The volcanic rocks exhibited an amygdaloidal microlithic-porphyritic texture. Subhedral to anhedral phenocrysts of labradorite, augite, and olivine were observed with holocrystalline groundmass composed of plagioclase, pyroxene, and …

Webgis-Based Data Center Design For Polar Science Studies: Simulation Of Türkiye, Müge Şenel, Hasan Hakan Yavaşoğlu, Burcu Özsoy, Hi̇mmet Karaman, Mustafa Ümi̇t Gümüşay

Turkish Journal of Earth Sciences

Scientific studies concentrated in Antarctica hold great value and importance for humanity. Research projects are conducted in various disciplines on the continent, where nearly 100 research stations from 30 countries are established. Despite the challenges posed by Antarctica's natural structure, unique environment, difficult working conditions, and limited logistics opportunities, scientific research conducted there is indispensable due to the valuable information it offers. In pursuit of accessing this information, Turkish Antarctic expeditions have been organized since 2017. In this study, a polar data center was established through a web-based geographic information system (WebGIS), a significant infrastructure for the continuity of scientific …

Accuracy Assessment Of Glacier Depth Monitoring Based On Uav-Gpr On Horseshoe Island, Antarctica, Mahmut Oğuz Selbesoğlu, Mustafa Fahri̇ Karabulut, Özgün Oktar, Burak Akpinar, Oleg Vassilev, Mehmet Arkali, Şeyma Nur Tufan, Alptuğ Şeref Ayyildiz, Esra Günaydin, Ati̇lla Yilmaz, Doğaç Baybars Işiler, Burcu Özsoy

Turkish Journal of Earth Sciences

Unmanned aerial systems have a wide range of uses in studying the impacts of climate change over several fields. Recently, its combination with a ground-penetrating radar (GPR) technology has been demonstrated to be highly effective for surveying glaciers, especially in difficult and inaccessible terrains like Antarctica. In this context, this study focused on exploring the potential of using an unmanned aerial vehicle (UAV)-GPR to measure the depth of glaciers on Horseshoe Island, West Antarctica. The data were collected during the seventh Turkish Antarctic Expedition (TAE-VII) in February and March 2023, within the scope of the international project titled "Glacier monitoring …

Beyond The Ice, Nikolaus T. Butz, Joshua Hunter, Emma Fisher

The Journal of Values-Based Leadership

Leadership is a management tool to direct effective achievement of goals. Historical investigation can provide a valuable lens for the study of leadership styles. To that end, this study examines the disparate approaches of Roald Amundsen and Robert Scott as they raced to be the first explorer to reach the South Pole. The objective of this study is to analyze the leadership techniques used in these expeditions, and to determine how they shaped the outcome of each. The process of tacit knowledge and experience coalesce and foster both leadership and action that is not only communication-oriented and value-driven, but also …

Paleotemperature Estimates From Diatom Morphometrics In The Amundsen Sea For Marine Isotope Stage 5, Cesar Lopez

Honors Capstones

Because of ever rising temperatures driven by anthropogenic climate change, much attention has been given to the West Antarctic Ice Sheet (WAIS) by the scientific community. This is due to its sensitivity to global climate change and vulnerability for collapse as evidenced by Pleistocene interglacial events. Paleotemperature estimates from the Amundsen Sea are crucial for understanding how global temperature changes impacted WAIS throughout the Pleistocene. Marine Isotope Stage 5 (MIS 5) is of particular interest as it contains different substages and intervals of fluctuating temperatures. This period also is estimated to have had temperatures equal to, or slightly higher than …

Snow Distribution And Influence In Taylor Valley, Antarctica, Using Remote Sensing, Katherine Mcnulty, Peter Doran, Mark Salvatore, Suniti Karunatillake

LSU Master's Theses

The McMurdo Dry Valleys is the largest ice-free area in Antarctica, but seasonal snow covers the valley floors sporadically throughout the year. In this study, a model to estimate areal snow coverage from satellite imagery was created. An area-volume model was created to estimate the amount of snow water equivalent (SWE) from the snow area extracted from the imagery. Snow cover influences the total albedo, the hydrologic budget, and the soil moisture and soil temperature in Taylor Valley (TV). Quantifying snow precipitation in TV is challenging because snow redistributes with winds, sublimates, or melts within a short period. Previous estimates …

Dataset: A Numerical Simulation Of The Ocean, Sea Ice And Ice Shelves In The Amundsen Sea (Antarctica) Over The Period 2006-2022 And Its Associated Code And Input Files, Pierre St-Laurent

Data

A three-dimensional numerical model of the Amundsen Sea (Antarctica) was used to simulate the period Jan.2006-Mar.2022 under consistent atmospheric/oceanic forcings, bathymetry/ice shelf topography, and model equations/parameters. The model is an implementation of the Regional Ocean Modeling System (ROMS, https://www.myroms.org/) with extensions for sea ice (Budgell 2005) and ice shelves (Dinniman et al. 2011). It simulates the ocean hydrography and circulation, sea ice thermodynamics and dynamics, and the basal melt of the ice shelves, with a uniform horizontal mesh of 1.5km and 20 topography-following vertical levels. Forcings include the ERA5 reanalysis (3-hourly), 10 tidal constituents from CATS 2008, and ocean/sea ice …

On The Relative Importance Of Offshelf/Onshelf Drivers Of Variability In Mcdw Inventory On The Amundsen Shelf, Antarctica, Pierre St-Laurent, S. E. Stammerjohn, T. Maksym, R. M. Sherrell

Presentations

Ice shelves in the Amundsen Sea (west Antarctica) are melting rapidly and may raise global sea levels substantially over the coming century through reduced buttressing. The high basal melt rates are associated with the presence of warm modified Circumpolar Deep Water (mCDW) that intrudes across the continental shelf and melts the floating portion of the ice sheet from its base near the grounding zone. How much mCDW is present on the continental shelf (its volume inventory) is thus thought to be a key proxy for the year-to-year variability in ice shelf melt rates. Over the past decade, the literature has …

The Global Impact Of The Antarctic Ice Sheet In A Warming World: Using Numerical Modeling And Critical Physical Geography To Assess Climate Change, Sea Level Rise, And Climate Justice

Doctoral Dissertations

Anthropogenic climate change is causing disruptions in the Earth system with negative ramifications for life on our planet. Increasing atmospheric greenhouse gas concentrations lead to accumulated heat content and the cryosphere is one of the earliest places to show changes in response to rising temperatures. The melting of the Antarctic Ice Sheet will have myriad effects on global climate due to interconnections and feedbacks between the ice sheet, ocean, and atmosphere. In this dissertation I use numerical modeling and critical geography to assess future climate conditions that occur in response to changes in Antarctic Ice Sheet melt as well as …

Glaciochemical Investigations In Three Southern Hemisphere Mountain Sites, Mariusz Potocki

Electronic Theses and Dissertations

The research presented in this dissertation focuses on glaciochemical records of trace elements, major ions, and stable water isotopes from three mountain regions: the Antarctic Peninsula, the Central Chilean Andes, and South Georgia Island.

The first section reports a significant increase in U concentration over 27 years on Detroit Plateau, Antarctic Peninsula. U concentrations in the ice core increase by as much as 102 between the 1980s and 2000s, accompanied by increased variability in recent years. The U concentration increase coincides with expanded open pit mining in the Southern Hemisphere, most notably Australia. Since other land-source dust elements do not …

Antarctic Ice Sheet Stability During Warm Periods: Integrating Numerical Modeling With Geologic Data, Anna Ruth W. Halberstadt

Doctoral Dissertations

Sea level rise is one of the major social and environmental challenges that threatens modern civilization, yet the response of polar ice sheets to future warming is deeply uncertain. Mass loss from the Antarctic Ice Sheet is projected to dominate global sea level rise in the near future, but how much, and when, remains a key unknown. The challenges associated with projecting Antarctica’s future sea level contribution are derived from a knowledge gap of physical ice sheet processes in a world warmer than today, and a lack of understanding of climatic thresholds that drive potentially irreversible retreat. Future and even …

Reconstructing The Ecological Relationships Of Late Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced These Relationships, Ian D. Broxson

2022 Symposium

The Sandwich Bluff Formation of the James Ross Basin of Antarctica has recently yielded a group of five late Cretaceous dinosaurs that lived contemporaneously with each other, a first for Antarctica. These five dinosaurs include fragmentary remains of two differently sized elasmarian ornithopods, a possible megaraptor, a hadrosaur, and a nodosaur. In this study we will construct a model of the ecological relationships of late Cretaceous Antarctica. Additionally, we will look at what specific factors allowed this group of four herbivores and a carnivore to coexist in a restricted locality and what niches were filled by each species. Methods to …

Sensitivity Of The West Antarctic Ice Sheet To +2 °C (Swais 2c), Molly O. Patterson, Richard H. Levy, Denise K. Kulhanek, Tina Van De Flierdt, Huw Horgan, Gavin B. Dunbar, Timothy R. Naish, Jeanine Ash, Alex Pyne, Darcy Mandeno, J. Paul Winberry

Geological Sciences Faculty Scholarship

The West Antarctic Ice Sheet (WAIS) presently holds enough ice to raise global sea level by 4.3 m if completely melted. The unknown response of the WAIS to future warming remains a significant challenge for numerical models in quantifying predictions of future sea level rise. Sea level rise is one of the clearest planet-wide signals of human-induced climate change. The Sensitivity of the West Antarctic Ice Sheet to a Warming of 2 ^∘C (SWAIS 2C) Project aims to understand past and current drivers and thresholds of WAIS dynamics to improve projections of the rate and size of ice sheet …

Microfabric Analysis Of Mid-Pliocene Amundsen Sea Interglacial Sediments Demonstrates A Link Between Iceberg Melt And Diatom Productivity (Iodp Exp. 379), Heather Leanne Furlong

Graduate Research Theses & Dissertations

Anthropogenically induced climate change in the polar regions has rapidly become an emergent global issue, especially for low-lying coastal communities, which are most affected by sea-level rise. The future of the West Antarctic Ice Sheet (WAIS) is of significant concern due to its history of instability and retreat, especially in light of the observed ongoing changes. Establishing rates of retreat is critical to forecasting future behavior of the WAIS, and previous studies have been unable to establish rates of ice sheet collapse in part because Antarctic continental shelf records are impacted by erosional hiatuses. In 2019, International Ocean Discovery Program …

A Subsurface Eddy Associated With A Submarine Canyon Increases Availability And Delivery Of Simulated Antarctic Krill To Penguin Foraging Regions, K. Hudson, M. J. Oliver, J. Kohut, Michael S. Dinniman, John M. Klinck, M. A. Cimino, K. S. Bernard, H. Statscewich, W. Fraser

OES Faculty Publications

The distribution of marine zooplankton depends on both ocean currents and swimming behavior. Many zooplankton perform diel vertical migration (DVM) between the surface and subsurface, which can have different current regimes. If concentration mechanisms, such as fronts or eddies, are present in the subsurface, they may impact zooplankton near-surface distributions when they migrate to near-surface waters. A subsurface, retentive eddy within Palmer Deep Canyon (PDC), a submarine canyon along the West Antarctic Peninsula (WAP), retains diurnal vertically migrating zooplankton in previous model simulations. Here, we tested the hypothesis that the presence of the PDC and its associated subsurface eddy increases …

Model Data For 'The Paris Agreement And Climate Justice: Inequitable Impacts Of Sea Level Rise Associated With Temperature Targets', Shaina Sadai, Natalya Gomez, Robert Deconto

Data and Datasets

This is the data repository associated with the manuscript "The Paris Agreement and climate justice: inequitable impacts of sea level rise associated with temperature targets". The data contained here is related to the sea level rise fingerprints generated for the study. These include the projected sea level rise fingerprint data at years 2100, 2200, and 2300 under emissions scenarios RCP4.5 and RCP8.5. For RCP4.5 data are from ice sheet simulations which include marine ice sheet instability. For RCP8.5 data is presented for two scenarios- one which includes only marine ice sheet instability and one that includes both marine ice sheet …

Causes And Characteristics Of Electrical Resistivity Variability In Shallow (<4 M) Soils In Taylor Valley, East Antarctica, William S. Gutterman

LSU Master's Theses

The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are characterized as a polar desert environment. Soils in the region are typically very dry (<1% soil water by weight) and remain frozen for most of the year. Increases in air temperature and incoming solar radiation during the austral summer generate meltwater from glaciers, ground ice, and snow patches supplying moisture to soils and altering the physical and chemical makeup of the subsurface. Previous studies have utilized airborne electromagnetic surveys (AEM) to analyze groundwater systems in the deep subsurface but have not yet examined soil moisture in the shallow (<4 m) subsurface. Here, I used electrical resistivity data from two AEM surveys (2011 and 2018) and soil geochemical data from three transects to characterize the spatial heterogeneity of soil properties in the near-subsurface of lower Taylor Valley. Soil resistivities from 2011 and 2018 range from 33.2 Ωm to 3535 Ωm with low elevations of <100 meters above sea level (masl) typically displaying the lowest resistivities and high elevations displaying greater resistivities. Liquid brine fractions were empirically estimated from electrical resistivity values using Archie’s Law and range from 0.3% to 68.2% for soils with resistivities <200 Ωm. Additionally, soil transect data show greater percentages of fine-grained sediments (<63 µm) exist at elevations <100 masl where soil resistivities begin decreasing. Resistivity variability in the subsurface is ultimately controlled by the site history, local and regional climate, soil salinity, soil moisture, soil lithology.

Seismicity And Pn Velocity Structure Of Central West Antarctica, Erica M. Lucas, Andrew A. Nyblade, Andrew J. Lloyd, Richard C. Aster, Douglas A. Wiens, John Paul O'Donnell, Graham W. Stuart, Terry J. Wilson, Ian W. D. Dalziel, J. Paul Winberry, Audrey D. Huerta

Geological Sciences Faculty Scholarship

We have located 117 previously undetected seismic events mainly occurring between 2015 and 2017 that originated from glacial, tectonic, and volcanic processes in central West Antarctica using data recorded on Polar Earth Observing Network (POLENET/ANET) and UK Antarctic Network (UKANET) seismic stations. The seismic events, with local magnitudes (M_L) ranging from 1.1 to 3.5, are predominantly clustered in four geographic regions; the Ellsworth Mountains, Thwaites Glacier, Pine Island Glacier, and Mount Takahe. Eighteen of the events are in the Ellsworth Mountains and can be attributed to a mixture of glacial and tectonic processes. The largest event noted …

Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu

Other Staff Materials

Due to a dearth of data from high-latitude paleomagnetic sites, it is not currently clear if the geocentric axial dipole (GAD) hypothesis accurately describes the long-term behavior of the geomagnetic field at high latitudes. Here we present new paleomagnetic and paleointensity data from the James Ross Island (JRI) volcanic group, located on the Antarctic Peninsula. This data set addresses a notable lack of data from the 60°–70°S latitude bin and includes 251 samples from 31 sites, spanning 0.99–6.8 Ma in age. We also include positive fold, conglomerate, and baked contact tests. Paleointensity data from three methods (Thellier- Thellier, pseudo-Thellier, and …

Miocene-Pleistocene Diatom Oxygen Isotope And Biogenic Silica Record From Iodp Site U1523, Ross Sea, Antarctica, Donald James Mclennan

Graduate Research Theses & Dissertations

The West Antarctic Ice Sheet (WAIS) plays a significant role in Earth’s climate. WAIS is currently retreating due to changes in wind-driven oceanic currents resulting in an increasing flux of warm waters to ice margins. Brine rejection in the Ross Sea is also major source of High Salinity Shelf water (HSSW) and Antarctica Bottom Waters (AABW), which creates a stratified ocean and plays a significant role in regulating Earth’s climate. Currently, there are very limited proxies that can quantify the variable input of HSSW formation on geologic time scales. Here we provide a 18Odiatom and biogenic silica (BSi) record which …

Power Scaling Of Ice Floe Sizes In The Weddell Sea, Southern Ocean, Tristan J. Coffey

Browse all Theses and Dissertations

The cumulative number versus floe area distribution of seasonal ice floes from four satellite images covering the Summer season (November - February) in the Weddell Sea Antarctica during the summer breakup and melting is fit by two scale-invariant power scaling regimes for the floe areas ranging from 7 to 20 x 108 m2. Scaling exponents, β, for larger floe areas range from -1.5 to -1.7 with an average of -1.6 for floe areas ranging from 6 x 106 to 55 x 107 m2. Scaling exponents, β, for smaller floe areas range from -0.8 to -0.9 with an average of -0.85 …

Biosynthetic Gene Clusters, Microbiomes, And Secondary Metabolites In Cold Water Marine Organisms, Nicole Elizabeth Avalon

USF Tampa Graduate Theses and Dissertations

Microorganisms and invertebrate animals from cold water marine environments, such as in Antarctica and in Ireland’s deep sea, are a rich source of secondary metabolites. In this dissertation, research was centered around secondary metabolism and natural product biosynthesis. The projects include the delineation of biosynthetic gene clusters hypothesized to be responsible for the biosynthesis of the palmerolides, stratification of the microbiome of the Antarctic ascidian Synoicum adareanum, genomic and peptidomic analysis of a host-associated Antarctic Pseudovibrio sp., and isolation and characterization of secondary metabolites from the Irish deep-sea coral Drifa sp.

Palmerolide A, the principle secondary metabolite associated with S. …

Plio-Pleistocene Paleoceonography Of The Ross Sea, Antarctica Based On Foraminifera From Iodp Sites U1523, U1522, And U1521, Julia Seidenstein

Masters Theses

The West Antarctic Ice Sheet (WAIS) is currently thinning and retreating because shifting oceanic currents are transporting warmer waters to the ice margin, which could lead to a collapse of the ice sheet and global sea level rise. International Ocean Discovery Program (IODP) Expedition 374 sailed to the Ross Sea in 2018 to study the history of the WAIS over the last 20 million years. Previous geologic drilling projects into Ross Sea sediments that record the history of the WAIS (DSDP Leg 28, RISP, MSSTS, Cape Roberts Drilling Project, ANDRILL), as well as modeling studies, show considerable variability of ice-sheet …

Conceptual Design Of A South Pole Carrier Pigeon Uav, Kendrick M. Dlima

Master's Theses

Currently, the South Pole has a large data problem. It is estimated that 1.2 TB of data is being produced every day, but less than 500 GB of that data is being uploaded via aging satellites to researchers in other parts of the world. This requires those at the South Pole to analyze the data and carefully select the parts to send, possibly missing out on vital scientific information. The South Pole Carrier Pigeon will look to bridge this data gap.

The Carrier Pigeon will be a small unmanned aerial vehicle that will carry a 30 TB solid-state hard drive …

Refractory Black Carbon (Rbc) Variability In A 47-Year West Antarctic Snow And Firn Core, Marquetto Luciano, Susan Kaspari, Jefferson Cardia Simões

All Faculty Scholarship for the College of the Sciences

Black carbon (BC) is an important climate-forcing agent that affects snow albedo. In this work, we present a record of refractory black carbon (rBC) variability, measured from a 20m deep snow and firn core drilled in West Antarctica (79°55’34.600” S, 94°21’13.3”W, 2122m above sea level) during the 2014–2015 austral summer. This is the highest elevation rBC record from West Antarctica. The core was analyzed using the Single Particle Soot Photometer (SP2) coupled to a CETAC Marin-5 nebulizer. Results show a well-defined seasonality with geometric mean concentrations of 0.015 μg L^-1 for the wet season (austral summer–fall) and 0.057 μg …

Constraining An Ocean Model Under Getz Ice Shelf, Antarctica, Using A Gravity‐Derived Bathymetry, Romain Millan, Pierre St-Laurent, Eric Rignot, Mathieu Morlighem, Jeremie Mouginot, Bernd Scheuchl

CCPO Publications

Getz Ice Shelf, the largest producer of ice shelf meltwater in Antarctica, buttresses glaciers that hold enough ice to raise sea level by 22 cm. We present a new bathymetry of its sub‐ice shelf cavity using a three‐dimensional inversion of airborne gravity data constrained by multibeam bathymetry at sea and a reconstruction of the bedrock from mass conservation on land. The new bathymetry is deeper than previously estimated with differences exceeding 500 m in a number of regions. When incorporated into an ocean model, it yields a better description of the spatial distribution of ice shelf melt, specifically along glacier …

Model-Based Estimates Of The Timing Of Brine Flux Into The Victoria Land Basin From The Mcmurdo Dry Valleys, Antarctica, Valerie Nicole Voisin

Graduate Research Theses & Dissertations

Submarine groundwater discharge (SGD) at a continental scale is one of the least constrained components of the hydrologic cycle and may represent a significant flux of iron and silica waters to the global ocean. Quantifying SGD along the Antarctic margin is complicated by complex subglacial and subsurface hydrogeology and limited observational data. Airborne transient electromagnetic (AEM) surveys have identified extensive high-salinity subsurface brines in the McMurdo Dry Valleys (MDV) that are hydrologically connected to surface features in the MDV (e.g. Taylor Glacier, saline lakes) and are potentially a significant source of SGD to McMurdo Sound. A 2D numerical model was …

Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl

OES Faculty Publications

Optical instruments can rapidly determine numbers and characteristics of water column particles with high sensitivity. Here we show the usefulness of optically assessed total particle volume below the main pycnocline to estimate carbon export in two systems: the open subarctic North Atlantic and the Ross Sea, Antarctica. Both regions exhibit seasonally high phytoplankton production and efficient export (i.e., a strong biological pump). Total particle volumes in the mesopelagic (200-300 m) were significantly correlated with those in the overlying surface mixed layer (50-60 m), indicating that most particles at depth reflect export from the surface. This connectivity, however, is modulated by …