Geology Commons^™

Holocene Glacial Activity In Barilari Bay, West Antarctic Peninsula, Tracked By Magnetic Mineral Assemblages: Linking Ice, Ocean, And Atmosphere, Brendan Reilly, Carl Natter, Stefanie A. Brachfeld

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

We investigate the origin and fate of lithogenic sediments using magnetic mineral assemblages in Barilari Bay, west Antarctic Peninsula (AP) from sediment cores recovered during the Larsen Ice Shelf System, Antarctica (LARISSA) NBP10-01 cruise. To quantify and reconstruct Holocene changes in covarying magnetic mineral assemblages, we adopt an unsupervised mathematical unmixing strategy and apply it to measurements of magnetic susceptibility as a function of increasing temperature. Comparisons of the unmixed end-members with magnetic observations of northwestern AP bedrock and the spatial distribution of magnetic mineral assemblages within the fjord, allow us to identify source regions, including signatures for ‘‘inner bay,’’ …

An Early Paleogene Palynological Assemblage From The Sabrina Coast, East Antarctica: New Species And Implications For Depositional History, Catherine Davies Smith

USF Tampa Graduate Theses and Dissertations

Palynological analyses of 13 samples from two sediment cores retrieved from the Sabrina Coast, East Antarctica, provide the first information regarding the paleovegetation within the Aurora Subglacial Basin. The assemblages, hereafter referred to as the Sabrina Flora, are dominated by angiosperms, with complexes of Gambierina (G.) rudata and G. edwardsii representing 38–66% of the assemblage and an abundant and diverse Proteaceae component. The Sabrina Flora also includes Battenipollis sectilis, Forcipites sp. and Nothofagidites spp. (mostly belonging to the N. cf. rocaensis-flemingii complex), along with a few fern spores, including Laevigatosporites ovatus, a moderate presence of conifers, and …

Sedimentology Of The Mid-Carboniferous Basal Fill Of The Olta Paleovalley, Eastern Paganzo Basin, Argentina, Levi Darwin Moxness

Theses and Dissertations

As global climate transitioned from the icehouse of the Late Paleozoic Ice Age (LPIA) to greenhouse conditions of the Late Permian, glaciers vanished across Gondwana; however, not all ice centers responded synchronously. The Paganzo basin, northwestern Argentina, was geographically adjacent to significant mid-Carboniferous ice centers that disappeared notably earlier than ice over much of Gondwana. Confining the extent of glacial ice during the LPIA and resolving the timing of its disappearance is of particular interest as this dramatic climatic transition is the closest analogue in Earth history to late Cenozoic climate change, potentially aiding in anticipating the response of modern …

Determining The Viability Of Recent Storms As Modern Analogues For North-Central Gulf Of Mexico Paleotempestology Through Sedimentary Analysis And Storm Surge Reconstruction, Joshua Caleb Bregy

Master's Theses

The northern Gulf of Mexico has been devastated by recent intense storms. Camille (1969) and Katrina (2005) are two notable hurricanes that made landfall in virtually the same location in Mississippi. However, fully understanding the risks and processes associated with hurricane impacts is impeded by a short and fragmented instrumental record. Paleotempestology could potentially use modern analogues from intense storms in this region to extend the hurricane record back to pre-observational time. Existing empirically based models can back-calculate surge heights over coastal systems as a function of transport distance, particle settling velocity, and gravitational acceleration. We collected cores in a …

Karst Landscape Influence On The Planetary Boundary Layer Atmosphere, Zachary S. Sullivan

Masters Theses & Specialist Projects

Karst landscapes cover approximately 20% of the ice-free land area worldwide. The soluble nature of the bedrock within a karst landscape allows for the formation of caverns, joints, fissures, sinkholes, and underground streams, which affect the hydrological behavior of the region. Currently, the Noah Land-Surface Model (Noah- LSM), coupled with the Weather Research and Forecasting (WRF) model, does not provide a representation of the physical behavior of a karst terrain. Previous research has attempted to model karst behavior through soil moisture and land cover/land use changes to determine the influence this unique landscape may have on atmospheric phenomenon. This highlights …

Trajectory Analysis Of Black Carbon In The Arctic Region, Kimberly Gottschalk

PSU McNair Scholars Online Journal

Black carbon (BC) is a troubling particulate. Commonly known as soot, BC forms through the incomplete combustion of fossil fuels, biofuels, and biomass. It has a very low albedo compared to natural particulates making it a very efficient absorber of solar radiation. As BC is deposited on snow and ice, albedo is decreased - enhancing solar heating and increasing meltwater production. With rising air temperatures, melting rates of polar ice are increasing and are being enhanced by BC, leading to accelerated global sea level rise.

This study aimed to document sources and deposition areas of BC in the Arctic. Utilizing …

Bathymetric Survey For Lakes Azuei And Enriquillo, Hispaniola, Michael Piasecki, Mahrokh Moknatian, Fred Moshary, Joseph Cleto, Yolanda Leon, Jorge Gonzalez, Daniel Comarazamy

Publications and Research

The two largest lakes on the Caribbean Island of Hispaniola, Lake Azuei in Haiti and Lake Enriquillo in the Dominican Republic, have experienced dramatic growth and surface area expansion over the past few years leading to severe flooding and loss of arable land around the lake perimeters. In order to better understand the reasons for this unprecedented rate of expansion and the resulting consequences a multi-disciplinary team comprised of researchers from Haiti, the DR, and the US have embarked on an extensive data collecting and hydrologic and climatological modeling campaign. While the sensor deployment entails stations that measure climatological data …

Testing Of The Late-Ordovician Pre-Gice Warm Water Carbonate Hypothesis In Alabama, Brandon Euker, Stacey Law

Senior Honors Projects, 2010-2019

The Guttenberg Carbon Isotope Excursion (GICE) (uppermost Sandbian-lower Katian, Late Ordovician) has been suggested to represent the transition from a Cambrian-Ordovician greenhouse world to Late Ordovician icehouse world. This transition is thought to coincide with a proposed shift from deposition of warm water carbonate rocks to cool water carbonate rocks in the North American midcontinent. We used oxygen isotopes (d¹⁸O) of conodonts to test the idea that the rocks below the GICE interval represent a consistently warm environment. Conodonts were isolated from samples of the Chickamauga Group collected at the Tidwell Hollow section in Blount County, AL, from …

Crop Modeling For Assessing And Mitigating The Impacts Of Extreme Climatic Events On The Us Agriculture System, Zhenong Jin

Open Access Dissertations

The US agriculture system is the world’s largest producer of maize and soybean, and typically supplies more than one-third of their global trading. Nearly 90% of the US maize and soybean production is rainfed, thus is susceptible to climate change stressors such as heat waves and droughts. Process-based crop and cropping system models are important tools for climate change impact assessments and risk management. As data- science is becoming a new frontier for agriculture growth, the incoming decade calls for operational platforms that use hyper-local growth monitoring, high-resolution real-time weather and satellite data assimilation and cropping system modeling to help …

Iceland: Extreme Learning In The Land Of Fire And Ice, Jason Polk, Leslie North

Leslie North

WKU Libraries kicked off the spring season of "Far Away Places" with Dr. Jason Polk and Dr. Leslie North, Asstant Professors from the Department of Geography and Geology at WKU, who talked about leading a study abroad group to Iceland in the summer of 2015. WKU Libraries kicks off the spring season of Far Away Places with Jason Polk and Leslie North, Asst. Professors from the Department of Geography and Geology at WKU, who will be talking about leading a study abroad group to Iceland in the summer of 2015. Dr. Polk and Dr. North co-taught this course with faculty …

Preservation And Sediment Cycling Beneath "Ghost Glaciers": How Cold-Based Ice Dictates Arctic Landscape Evolution, Lee Corbett

Graduate College Dissertations and Theses

Constraining past episodes of climate change and glacial response is critical for understanding future impacts of climate change, especially in the high latitudes where warming is expected to be rapid and most of Earth's glaciers exist. Many studies of past glacier size utilize rare isotopes called cosmogenic nuclides to perform surface exposure dating. Since most areas of Earth's surface that were previously glaciated were covered by erosive ice, which stripped away pre-existing cosmogenic nuclides, surface exposure dating yields the timing of the most recent deglaciation. However, in some high latitude areas where glacial ice is cold-based and non-erosive (so-called 'ghost …