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University of Nebraska - Lincoln
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Human And Hydrologic Influences On Nebraska's Endangered Rainwater Basin Wetlands, Sarah Thompson
Human And Hydrologic Influences On Nebraska's Endangered Rainwater Basin Wetlands, Sarah Thompson
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Over half of wetlands in North America have been lost or degraded. Rainwater Basin (RWB) wetlands, located in south-central Nebraska, are a primary example of such loss; an estimated 90% have been destroyed by land conversion for agriculture. Remaining RWB wetlands are often embedded in row-crop fields, where they are threatened by altered surface water runoff flow, drainage features, and excess sediment inputs. Efforts at the state and federal level have been made to preserve this wetland complex due to the critical stopover habitat these wetlands provide for migratory birds. Land managers work to maintain sufficient water levels during migratory …
An Observational Study Of Winter Weather-Related Traffic Crashes In Nebraska, Jacob Petr
An Observational Study Of Winter Weather-Related Traffic Crashes In Nebraska, Jacob Petr
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
The responsibilities of meteorologists have evolved over time from simply providing a forecast to needing to also understand how those predictions will impact society and then communicating those risks in a clear, concise, and consistent manner. Increased motor vehicle crash numbers due to adverse weather conditions represent one such impact worthy of further study. Snowfall, in particular, significantly increases the overall risk of a crash, which can result in extensive property damage, severe injuries, and even loss of life.This project seeks to supplement traffic crash information in Nebraska by assessing how snowfall impacts crashes across the state. Crash data were …
Changes In Mammalian Abundance Through The Eocene-Oligocene Climate Transition In The White River Group Of Nebraska, Usa, Robert Gillham
Changes In Mammalian Abundance Through The Eocene-Oligocene Climate Transition In The White River Group Of Nebraska, Usa, Robert Gillham
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Marine records show major cooling during the Eocene-Oligocene Climate Transition (EOCT). Most proxy studies in the White River Group suggest drying across the EOCT, and some suggest cooling. The lower resolution continental record has hindered a direct correlation of the marine climate record to Nebraska. I explore various correlation schemes and what they imply for faunal changes. This study compiles and analyzes data from 4,875 specimens in the University of Nebraska State Museum (UNSM) collection to test the hypothesis that climate change across the Eocene-Oligocene (E-O) boundary caused significant abundance changes in mammals. A series of binning schemes was created. …
Modeling And Satellite Remote Sensing Of The Meteorological Impacts Of Irrigation During The 2012 Central Plains Drought, Clint Aegerter
Modeling And Satellite Remote Sensing Of The Meteorological Impacts Of Irrigation During The 2012 Central Plains Drought, Clint Aegerter
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
As irrigation is increasingly needed for agricultural production, it is becoming progressively more important to understand not only how irrigation impacts water availability, but how the introduction of this water into the soil impacts weather and climate through land-atmosphere interactions. In the summer of 2012, the Central Plains of the United States experienced one of its most severe droughts on record. This study examines the meteorological impacts of irrigation during this drought through observations and model simulations using the Community Land Model (CLM) coupled to the Weather Research and Forecasting (WRF) model. A simple parameterization of irrigation processes is added …
Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting
Constraining Neogene Temperature And Precipitation Histories In The Central Great Plains Using The Fossil Record Of Alligator, Evan Whiting
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Most amphibians and reptiles (excluding birds) are poikilothermic; their internal body temperature varies with that of their external environment. This makes them useful as climate proxies, especially when linked to geographic distributions of ambient climate. I evaluate the utility of the extant crocodylian genus Alligator as a paleoclimate proxy for the Central Great Plains (CGP) using species distribution modeling. Alligator is a readily identifiable taxon with a good CGP fossil record during the Neogene (~23–2.6 Ma). Alligator first appeared in the CGP in the late Eocene (~37 Ma), was absent during most of the Oligocene, reappeared in the early Miocene …
Oil-Source Rock Correlation In The Late Paleozoic, Denver Basin, Nebraska -The Search For A Negative Δ¹³C Anomaly In Pennsylvanian-Permian Cyclothems, John P. Still
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Late Paleozoic sedimentation in the Denver basin occurred in two environmentally distinct depocenters. The northern-most Alliance Basin has been interpreted to have a restricted character: anhydrite-bearing mudstones are present in cyclothems comprising wackestone, packstone and mudstone. The source of petroleum produced from these intervals is considered to be organic-rich units within these cyclothems. Oil recovered from late Paleozoic reservoirs has δ13C values that range from -30.8‰ to -28.8‰: values that are lower than those reported previously for prospective source rocks from this interval. Cores from seven wells that penetrate upper Pennsylvanian to lower Permian rocks have been chosen for analysis. …
Sedimentology And Stratigraphy Of The Upper Pennsylvanian – Lower Permian Systems Of Western Nebraska, Usa, Chesney L. Gilleland
Sedimentology And Stratigraphy Of The Upper Pennsylvanian – Lower Permian Systems Of Western Nebraska, Usa, Chesney L. Gilleland
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Depositional patterns and regional stratigraphic relationships in the carbonate-dominated Pennsylvanian and Permian deposits in western Nebraska are not well established due to poor surface exposure. Examination of petroleum drillcores and wireline logs, along with thin sections and biostratigraphic analysis allow new insight into facies distributions, depositional environment, and regional stratigraphic relationships. Nine shallowing upward cycles are identified that can be correlated across the southern Nebraska Panhandle within the Pennsylvanian (Virgilian)-Permian (Wolfcampian) stratigraphy (Admire, Council Grove, and Chase Groups). These cycles are composed of facies representing deposition from open marine through nonmarine environments. Results show that depositional settings in western Nebraska …