Alumni Dissertations and Theses

 
 

Alumni Dissertations and Theses

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  • POLICY CHANGE, SUSTAINABILITY, AND ENVIRONMENTAL JUSTICE: APPLICATIONS OF THE LONG ISLAND MARKAL MODEL

    Author:
    David Friedman
    Year of Dissertation:
    2013
    Program:
    Earth & Environmental Sciences
    Advisor:
    Yehuda Klein
    Abstract:

    The objective of this study is to develop a robust and sustainable energy (electricity) path for Long Island. Waste water management and solid municipal waste have been incorporated into a MARKAL energy-planning model for the short through long term (50 years) planning horizons. In addition, an analysis of the impacts on the local scale, of a carbon tax has been carried out. By examining the Long Island MARKAL the nexus of sustainability and environmental justice is elucidated. Suggestions for examining, testing, and improving sustainability plans are also provided.

  • And Then the Neighborhood Changed: Jewish Intra-Urban Migration and Racial Identity in the Bronx, NY

    Author:
    Bradley Gardener
    Year of Dissertation:
    2012
    Program:
    Earth & Environmental Sciences
    Advisor:
    Marianna Pavlovskaya
    Abstract:

    The major research goal is to explain the causes of urban Jewish migration from the West Bronx to Riverdale and determine how it impacted their racial identity. I ask the following questions: Why did Jews leave the West Bronx? Why did they move to Riverdale? How did moving between these places affect the racial identity of Jews? Employing a relational understanding of race and space, I use a mixed method approach consisting of both qualitative and quantitative techniques to examine how the racial identity of Jews was affected by moving from the West Bronx to Riverdale. The primary methods employed in my study were participant observation, residential histories, and GIS. My study makes three primary theoretical contributions. First, my research shows that white identity or whiteness is fluid. As Jews moved from the West Bronx to Riverdale, their white identities changed. More specifically, their white identities changed in relation to material processes like neighborhood disinvestment and migration. These processes condensed into a historically and geographically specific articulation of white identity related to the conditions under which my participants moved from the West Bronx to Riverdale. In a second related contribution, my research shows that the connections scholars make between Jewish whiteness to suburbanization is largely an over generalization. Although the race of Jews was impacted by suburban migration, it was not the only way in which they negotiated the racialization process. Further, contrary to the notion that Jews assimilated into static racialized places, they profoundly changed the places they moved into. As their identities changed, so did the meaning of the places they inhabited. Third, my research opens up possibilities for reimagining narratives of white flight and racialized interpretations of neighborhood change. Often, white flight movers are made legible through rational choice theory. My research challenges the logic of white flight, showing that my participants didn't move to the suburbs because they wanted to continue urban Jewish living.

  • Cryospheric Teleconnections: The Response of Northern Hemisphere Snow to the Atmospheric and Arctic Sea Ice Variations

    Author:
    Debjani Ghatak
    Year of Dissertation:
    2011
    Program:
    Earth & Environmental Sciences
    Advisor:
    Allan Frei
    Abstract:

    The primary focus of this dissertation is the land-surface snow cover, which plays a significant role in modulating the earth's surface energy balance. It is an indicator of climatic variations as well as a part of the earth's system of feedback mechanisms that control the climate. The main goal of the thesis is to contribute to our understanding of the factors causing variations in snow. In order to fulfill this goal, specific objectives are formulated with a particular focus on an under-utilized snow pack metric, i.e. the snow depth. These objectives include the spatially robust explanation of climate-driven North American snow depth variability as well as the investigation of any evidence of a climate change signal and/or Arctic sea ice loss signal in the Northern Hemisphere snow cover record. This thesis identifies major winter climate teleconnection modes i.e. the North Atlantic Oscillation (NAO) and the Pacific-North American pattern (PNA) as the two main drivers of the snow depth variations over North America. Furthermore, the distinct mechanistic pathways linking circulation patterns to snow variations are also determined. These involve regional winter circulation patterns and hydrologic fluxes. Next, analyses of observational datasets show increased snow over Siberia during fall and early winter, which may be related to the loss of summer Arctic sea ice. Historic and future simulations of Community Climate System Model version3 (CCSM3) indicate the emergence of a similar signal during the last half of the 21st century. Finally, a suite of Community Atmosphere Model Version 3 (CAM3) experiments is analyzed, which suggests a key role played by the high-latitude surface forcings due to the SST and sea ice in generating the snow signal over the Eurasian landmasses as emerges in observations. This thesis contributes to the state of the knowledge of snow - climate interactions by focusing on the snow depth - climate interaction. Furthermore, the identification of a snow response to the recent climatic changes including the loss of Arctic sea ice is another original contribution. Thus, this work may enhance the prediction capabilities of the future hydro-climatic changes over the high latitude regions.

  • Mapping Forest Canopy Structure with On-Demand Fusion of Remotely Sensed Data

    Author:
    Gordon Green
    Year of Dissertation:
    2014
    Program:
    Earth & Environmental Sciences
    Advisor:
    Sean Ahearn
    Abstract:

    Current methods of mapping forest canopy structure often result in data products that are limited in resolution, coverage, or ease of access. On-demand processing introduces several new ways in which existing data products can be combined and re-purposed, mitigating some of these limitations. In this research, we investigate several methods of extending the spatial and temporal resolution, coverage, and accessibility of existing forest canopy datasets by processing them on demand. These methods include downscaling coarse-resolution canopy height data dynamically to estimate height at 30 m and 1 m resolution for any location within the contiguous United States. A related method involves sampling individual trees from field measurements on demand to estimate local forest canopy characteristics, using globally-available remotely sensed data and field data from across the United States. Canopy height profiles, which are highly sensitive to horizontal canopy variability, are generated on demand for any location within North America using new methods that account for this variability. Trends in canopy coverage and above-ground biomass are generated for any location globally using methods sensitive to local conditions. Each of the techniques developed as part of this research extends the resolution, coverage, or ease-of-access of existing remote sensing datasets, by combining multiple existing resources on demand.

  • Microfossils as proxies for Holocene climate in semi-enclosed basins: the Hudson River estuary, New York, USA and the Marmara Sea, Turkey

    Author:
    Damayanti Gurung
    Year of Dissertation:
    2015
    Program:
    Earth & Environmental Sciences
    Advisor:
    Cecilia McHugh
    Abstract:

    The transition from the late Pleistocene glacial to the warmer Holocene interglacial occurred within a series of climatic oscillations. The Holocene, a relatively warm and stable period, was also marked by smaller climatic variability of millennial- to-centennial-scale oscillations. Furthermore, during this period global sea level was much lower than at present. My present study will analyze micro-fossils as proxies for their response to these climatic fluctuations, as well as marine influences during the late Pleistocene to Holocene periods. Sediments from marginal basin environments have been selected for the study due to their connection to the open sea and terrestrial environments, providing high-resolution sedimentary records that document the interaction of marine and terrestrial processes. Such sedimentary records are studied in brackish and marine sediments from the Hudson River estuary and Marmara Sea, respectively. The retreat of the Laurentide Ice Sheet during the late Pleistocene to early Holocene periods permitted fluvial and estuarine conditions to develop in the Hudson Valley. As glacial lakes were breached, the global sea-level rose and flooded the Hudson Valley, fresh and marine waters mixed, recording in the sediments the changes in climate. The objectives of this study are to use the microfossil diatom flora as proxies for salinity and changes in freshwater discharge from the mid- to late Holocene. Multibeam bathymetry and five long sediment cores were studied from Newburgh to Peekskill. Detailed sedimentologic and biostratigraphic (diatoms) analyses were conducted together with geochemical scanning. These results were correlated to a calibrated radiocarbon and short-lived radionuclides chronology, permitting the correlation of the Hudson River estuary results to previously documented regional climate studies. The diatom assemblages show that marine influence was strongest, with freshwater inflow reduced, from 6500 to 3500 cal. yr. BP. This interval was interrupted by an increase in freshwater benthic epiphytic diatoms, from 5400 to 5800 cal. yr. BP, suggesting an increase in freshwater discharge. The freshwater diatoms begin to increase in abundance from ~3500 to 1300 cal. yr. BP, indicative of increase in freshwater influences. The gradual increase in the abundance of freshwater diatoms indicates a decrease in salinity in the area. After 1300 cal. yr. BP, the sediment was dominated by freshwater diatoms with decrease in salinity suggesting further increase in freshwater influences. The Diatom Salinity Index (DSI) measured for the last 6500 cal. yr. BP similarly show comparable changes with an overall trend toward a gradual decrease in salinity. During the late glacial, Marine Isotope Stage 2, the Marmara Sea transformed into a brackish lake as global sea level fell below the sill in the Dardanelles Strait. The goal of this study is to develop a high-resolution record of the lacustrine-to-marine transition of Marmara Sea, in order to reconstruct regional and global climatic events at a millennial scale. For this purpose, the paleoshorelines of Marmara Sea were mapped along the northern, eastern, and southern shelves at Çekmece, Prince Islands, and Imrali, using data from multibeam bathymetry, high-resolution subbottom profiling (chirp) and ten sediment cores. Detailed sedimentologic, biostratigraphic (foraminifers, mollusk, diatoms), and geochemical analyses were correlated to a calibrated radiocarbon chronology. The results provide evidence for cold and dry conditions prior to 15,000 cal. yr. BP, warm conditions of the Bölling-Allerod from ~15,000 to 13,000 cal. yr. BP, a rapid marine incursion at 12,000 cal. yr. BP, and a still stand of sea-level and sediment reworking of the paleoshorelines during the Younger Dryas at ~11,500 to 10,500 cal. yr. BP. The development of a strong stratification and influx of nutrients as Black Sea waters spilled into Marmara Sea occurred at 9200 cal. yr. BP. Stable environmental conditions developed in Marmara Sea after 6000 cal. yr. BP as sea level reached its present shoreline and the basin floors filled with sediments, achieving their present configuration.

  • Tiebout Sorting and Jurisdictional Homogeneity: Empirical Validity and Ethical Implications

    Author:
    Lee Hachadoorian
    Year of Dissertation:
    2011
    Program:
    Earth & Environmental Sciences
    Advisor:
    Jochen Albrecht
    Abstract:

    In a seminal paper, Tiebout (1956) argues that a large number of small local governments will function as a market in local services, leading to efficient allocation of local public goods. This result only obtains if households actually move in response to local fiscal differences. Spatial dependence of socioeconomic variables confounds attempts to infer Tiebout-motivated residential choice from observed socioeconomic homogeneity. I correct for this by focusing on socioeconomic difference across local government borders. In an investigation of socioeconomic sorting in Queens and Nassau Counties, NY, I find strong evidence of income sorting at the level of small suburban municipalities and of racial sorting across school districts. There is no evidence of income sorting across school districts, which I attribute to NYS school districts' lack of control over zoning. This study design exploits the incongruent boundaries of municipalities and school districts in New York State. In neighboring New Jersey, school districts are by law coterminous with municipalities. I hypothesize that, where boundaries are coterminous, sorting by school district and municipality will be mutually reinforcing. This hypothesis is tested in a comparison of income and racial heterogeneity in Nassau County, NY, with Bergen County, NJ, both suburban commuter counties within the New York MSA. Sorting is not found to be higher in Bergen than in Nassau. These negative results imply that the argued advantages of coterminous boundaries in terms of citizen oversight (Schwartz 2001) need not be traded off against increased segregation. I conclude with a discussion of the scope of public services that may be allocated via the Tiebout mechanism. Education is a primary good of such importance to well-being and to democracy that a pure system of local finance violates Rawlsian principles of justice (Rawls 1971). If good reasons exist, in terms of efficiency and/or democratic participation, for supporting local control in public goods with such significant distributive impacts, equalizing transfers are necessary to achieve just outcomes. This policy of equalizing transfers is consistent both with a spatialized Rawlsian theory of justice, as well as with the welfare economist's concept of efficiency (Schwab, Oates 1991).

  • Paleoecology of Late Cretaceous methane cold-seeps of the Pierre Shale, South Dakota

    Author:
    Kimberly Handle
    Year of Dissertation:
    2014
    Program:
    Earth & Environmental Sciences
    Advisor:
    Neil Landman
    Abstract:

    Most investigations of ancient methane seeps focus on either the geologic or paleontological aspects of these extreme environments. In contrast, this thesis encompasses both disciplines to evaluate the paleoecology of these systems with greater detail than previously published either within the Western Interior Basin or elsewhere. This thesis addresses the following questions: 1) Are the changes in mineralogy of a seep discernable and predictable as a seep shifts from a clay-based environment to a carbonate-based environment? 2) What are the foundation organism(s) of Late Cretaceous methane cold-seeps? 3) Is there a correlation to the mineralogic changes and shifts in community structure? 4) What is the mediating factor of these shifts? and 5) Are there any spatial trends in seep formation and persistence? To help resolve these queries, seep cement material and fossils were collected from 25 locations from the Baculites scotti - Didymoceras nebrascense, Didymoceras cheyennense, and Baculites compressus zones spanning ~2 million years in the Campanian of the Pierre Shale in South Dakota. The mineralogy of cements was determined through microprobe and electron dispersive spectroscopy. These data was spatially analyzed and suggest that there is a potential shift in mineralogy due to relative fluid flow rates over space and time: Baculites scotti - Didymoceras nebrascense Zone was of consistent moderate flow rates, Didymoceras cheyennense Zone was dominated by low fluid flow rates, and Baculites compressus Zone contained an unusually large number of high fluid flow seep assemblages compared to other biostratigraphic zones. Over 8000 individual organisms were counted and identified to the genus or species level (where possible) and these data were then processed with a series of diversity indices. A faunal pattern was found and shows that the foundation organisms, baculites, inoceramids, and lucinids, always dominate these seep assemblages, unlike the foundation organisms in modern methane cold-seep analogs. These fossil data were then paired up with each location's mineral data and a correlation was found between shifts in mineralogy and basic seep structure (general flow rate) and shifts in faunal compositions. Furthermore, specific fauna patterns and flow rates may indicate changes in oxygen or food availability. However, Akaike modeling techniques implemented found that the shifts in community composition within the cold-seeps of the Pierre Shale of South Dakota are most likely a reflection of sulfur availability according to the data.

  • THE STATE OF THE OLIGOCENE ICEHOUSE WORLD: SEDIMENTOLOGY, PROVENANCE, AND STABLE ISOTOPES OF MARINE SEDIMENTS FROM THE ANTARCTIC CONTINENTAL MARGIN

    Author:
    Daniel Hauptvogel
    Year of Dissertation:
    2015
    Program:
    Earth & Environmental Sciences
    Advisor:
    Stepehn Pekar
    Abstract:

    The Oligocene Epoch (34-23 Ma) was a dynamic time in Antarctica, with previous ice volume estimates suggesting fluctuations from below 50 % up to 140 % of modern all while atmospheric CO2 decreased from above 1,000 ppm in the Early Oligocene to near modern levels by the Late Oligocene. Most of what is known about the Oligocene Antarctic cryosphere however, is derived from distal sedimentary records that can only provide a generalized view of the cryospheric dynamics in Antarctica. To better understand regional differences in Antarctic glacial dynamics, proximal records are needed. This dissertation advances our understanding of these dynamics in Antarctica during the Oligocene by investigating three proximal, marine sediment cores from different regions of the continent. Ice-rafted debris (IRD) concentrations, 40Ar/39Ar thermochronology, and stable isotope records combined from 3 proximal marine sediment cores reveal a large ice sheet existed throughout the Oligocene, with ice volume reaching up to 155 % of modern. Concentrations and 40Ar/39Ar thermochronology from IRD offshore of the Wilkes subglacial basin suggest the ice sheet was fairly stable on elevated portions such as the Adélie Craton, but the basin itself was more responsive to climate changes. These changes appear to be influenced by 405-kyr eccentricity and 1.2 myr obliquity. In the Ross Sea, 40Ar/39Ar thermochronology from IRD show a large West Antarctic influence, indicative of a large ice sheet residing there during the Late Oligocene. Stable isotopes from benthic foraminifera from the Maud Rise show ice volume fluctuations from below 50 % up to 155 % of modern, in agreement with modeling and far-field records. The isotope record is also influenced by 405-kyr and 100-kry eccentricity and does not show a warming trend during the Late Oligocene as seen in other isotope records. Together, these records are indicative of a near-modern size or larger ice sheet present in both East and West Antarctica during the Oligocene, a time when the extent of Antarctica glaciation has been debated.

  • BIODEGRADATION OF FUEL OXYGENATES IN NORTHEASTERN UNITED STATES AQUIFERS WITH AN ANALYSIS OF UNDERGROUND STORAGE TANK LEAKS

    Author:
    Gordon Hinshalwood
    Year of Dissertation:
    2009
    Program:
    Earth & Environmental Sciences
    Advisor:
    David Locke
    Abstract:

    Abstract BIODEGRADATION OF FUEL OXYGENATES (MTBE) IN GROUND WATER AQUIFERS OF THE NORTHEASTERN UNITED STATES/LEAKING UNDERGROUND STORAGE TANK CAUSATION ANALYSIS by Gordon Hinshalwood Adviser: Professor David Locke During the past decade the application of monitored natural attenuation has become one of the predominant technologies used in the remediation of gasoline spills impacting subsurface soils and groundwater. The success of this method has depended, for the most part, on the biodegradation of those gasoline constituents that dissolve into groundwater and transport with the groundwater most readily. One of the most mobile components of gasoline formulations during the past 20 years has been methyl tertiary butyl ether (MTBE), which has traditionally been viewed in both the scientific and the regulatory communities as relatively recalcitrant to biodegradation. However, cases of both in and ex situ MTBE biodegradation have recently been documented. In order to better understand and perhaps enhance the process of in situ MTBE biodegradation, a fundamental understanding of where, when and under what hydrogeological conditions MTBE biodegradation occurs is needed. To this end, the northeastern United States offers a wide range of lithologies to study. This study examines which subsurface conditions are most conducive to MTBE biodegradation. Retail gasoline service stations with leaking underground storage tank (LUST) releases located within a variety of hydrogeological conditions in the northeastern United States were screened for lithology, MTBE concentration in ground water, monitoring well network location, and MTBE concentration trends. Ground water samples were collected from those sites that passed this initial screening phase. MTBE from the samples collected were analyzed using stable carbon isotope ratio analysis (SCIRA) to determine where biodegradation is occurring. Geochemistry in each well was also examined to determine which hydrogeological conditions are most conducive to MTBE biodegradation. MTBE biodegradation under a variety of subsurface conditions was observed in this study. Loose soil conditions combined with reduced aquifer redox potential exhibited the greatest MTBE biodegradation frequency. Although statistically significant correlations were not found with respect to MTBE biodegradation and aquifer geochemistry, scatter plots showed notable trends with respect to pH, dissolved oxygen, and methane concentration correlated with MTBE biodegradation. Increased biodegradation frequency in the presence of increasing methane concentrations under varied aquifer redox and lithological conditions was observed.

  • The Work of the Urban Commons: Limited-Equity Cooperatives in Washington, D.C.

    Author:
    Amanda Huron
    Year of Dissertation:
    2012
    Program:
    Earth & Environmental Sciences
    Advisor:
    Marianna Pavlovskaya
    Abstract:

    This research theorizes the work of the urban commons through close examination of a group of ten limited-equity housing cooperatives in Washington, D.C. Limited-equity co-ops, or LECs, are a noncommodified resource that is collectively owned and maintained by their members. I argue that LECs are a manifestation of the commons, and that they represent a specific form of the commons - the urban commons. In this research, I ask: how does the urban commons - as manifested in this case by limited-equity housing cooperatives - function? The commons, as I theorize it, is a space that both provides a basis for life outside of (or at least less dictated by) capitalism, and that requires collective work to build and maintain. The commons, Peter Linebaugh (2008) argues, is constituted through commoning - the many overlapping practices of being-in-common that allow for a collective approach to life. The urban commons, I argue, is constituted through work, and future theorizing and action around the commons needs to take work seriously.