Master of Arts, The Ohio State University, 2024, Geography

Drone-based remote sensing offers a practical platform for studying debris-covered ice and rock glaciers where the surface topography makes fieldwork challenging or prohibitive. Situated between the scale provided by terrestrial or satellite mapping, drones have been widely used over the past decade to construct high resolution maps of surface deformation and flow of glaciers and rock glaciers using structure from motion photogrammetry. However, ground penetrating radar (GPR) is a standard tool for studying ice within debris-covered glaciers and rock glaciers that has not seen widespread deployment in a drone-based capacity. This thesis demonstrates the application of both photogrammetry and GPR as drone-based tools to study buried ice. Fieldwork involved drone photogrammetry of the Lehman Rock Glacier (LRG) at Great Basin National Park (GBNP) in Nevada, USA and drone-based GPR of a debris-covered glacier at Shar Shaw Taga (also called Grizzly Creek) in Kluane National Park and Reserve in southwest Yukon, Canada. Drone photogrammetry of the LRG demonstrated that the upper lobe of the rock glacier is active and flowing at rates of approximately 0.2 – 0.4 m/yr at the center of the upper lobe between 2018 and 2023 with surface elevation loss in the range of 0.75 – 1.5 meters over the same period. The total volume lost is estimated to be 21,000 m3. Drone-based GPR at Shar Shaw Taga demonstrated successful detection and measurement of buried ice along the drone-based transect validated by traditional manual GPR. The inclusion of manual common mid-point (CMP) surveys enabled accurate measurements of depths and layer characteristics along the entire drone radar transect. The limitations and opportunities of the drone-based photogrammetry and GPR are discussed for potential future investigations using these methods.

Committee: Bryan Mark (Advisor); Demián Gómez (Committee Member); Ian Howat (Committee Member); Alvaro Montenegro (Committee Member) Subjects: Geography; Physical Geography

Doctor of Philosophy, The Ohio State University, 2022, Geography

This dissertation comprises of a multi-part investigation into the impacts and contributions of debris-covered glaciers to the surface hydrology of the Cordillera Blanca, Peru. Due to the circumstances surrounding the global pandemic, the originally planned in situ dataset was not collected; however, following a pivot in research goals and objectives, field collected (prior to 2020) streamflow and water quality data, and remotely sensed imagery were used to answer the slightly broadened questions of this dissertation. First, without a specific focus on debris-covered glacier catchments, long-term hydrological shifts were identified throughout the past 70-years, and short-term daily fluctuations were assessed throughout the Rio Santa watershed. Multiple change points were identified to have occurred over the historical record, with the most recent changes in the 2000s that indicate lower rates of loss in discharge now compared to prior decades. High-temporal resolution discharge data is presented which provides evidence that diurnal changes in streamflow are driven by seasonal fluctuations and have not undergone significant shifts in timing or amplitude during the past 14-years. Second, high-resolution satellite imagery was used to calculate the spatial and temporal changes and estimate volumes of supraglacial ponds on the surface of debris-covered glaciers for the first time across the Peruvian Andes. Expanding the study area beyond the Cordillera Blanca allowed for the opportunity to test patterns in debris-covered glacier ponds more broadly and place the Cordillera Blanca in a regional context. From these analyses, debris-covered glacier pond area maxima were recorded to have occurred in 2012 and 2013 across the Peruvian Andes. Furthermore, as minimum temperatures significantly rose over the past 11 years, a decrease in total supraglacial pond area was measured. Finally, water volume estimates provide strong indications that debris-covered glaciers contribute sign (open full item for complete abstract)

Committee: Bryan Mark (Advisor); Michael Durand (Committee Member); Robert Hellstrӧm (Committee Member); Alvaro Montenegro (Committee Member) Subjects: Environmental Science; Hydrology; Physical Geography; Water Resource Management

Doctor of Philosophy, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects: Education

Master of Science, The Ohio State University, 1965, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Philosophy, The Ohio State University, 2024, Chemistry

The development of commercially available single particle inductively coupled plasma time of flight mass spectrometers (spICP-TOFMS) has made it possible to measure the elemental compositions, mass equivalent diameters, and number concentrations (number of particles detected per volume of analyzed sample) of thousands of individual multi-element nanoparticles and microparticles using a small volume (<10 mL) of sample suspension in minutes. Effective particle analysis by spICP-TOFMS requires a deep understanding of the technical challenges and limitations of the technique. Solution-NP and NP# transport efficiency methods can vary up to a factor of two, resulting in a 20% difference in particle mass equivalent diameters and a factor of two difference in particle number concentrations. Particle transport efficiency depends on the uptake rate. Nanoparticles transport efficiency is ~30% and ~20% at 20 and 60 µL/minute, respectively. Particle transport efficiency decreases for particles larger than ~500 nm. Element- and sample-dependent quasi-continuous backgrounds limit the smallest particle mass equivalent diameter that can be determined in samples. Diluting a sample can reduce element thresholds by a factor of ~2. The smallest detectable amount of each element is sample and isotope dependent. The linear dynamic required to measure nanoparticles and fine microparticles is over seven orders of magnitude. Particles as large as 3170 nm are vaporized, atomized, and ionized in the ICP but produce signals outside the linear dynamic range the instrument using optimized sensitivity. Four ice core samples from the Alto Dell'Ortles glacier, Italy, from pre-Roman (780 BCE) to modern (1955 CE) times with a focus on lead (Pb)-bearing particles were measured by spICP-TOFMS. The number concentration and mass equivalent diameter distributions of all detected insoluble mineral particles were similar in the four samples. However, the number concentration and the mass fraction of Pb i (open full item for complete abstract)

Committee: John Olesik (Advisor); Stanislav Kutuzov (Committee Member); Amanda Hummon (Committee Member); Susan Olesik (Advisor) Subjects: Analytical Chemistry; Chemistry; Geochemistry; Geology

Master of Arts, The Ohio State University, 2022, Geography

Improving tropical glacier modeling capacity is crucial for deriving climatological insight from tropical glacier fluctuations on historical to multi-millennial timescales and for predicting socially relevant glacier environmental changes under anthropogenic climate warming. Using the glacierized Queshque Valley of Peru's Cordillera Blanca as a case study, this thesis first develops data assimilation and calibration methods to adapt a coupled temperature-index mass balance and glacier flow model to tropical settings. The calibrated model is applied to project glacier evolution in the valley under an ensemble of climate change scenarios, confirming the high probability of near complete deglaciation by the end of this century. Despite the glacier's current trajectory, moraine features signal that ice once extended about 6km further down valley. Three cosmogenic nuclide dated moraines reveal extended ice cover at 10.8ka, 9.4ka, and 6.2ka BP, and historical maps show that the glaciers have retreated considerably since 1962 CE. Equilibrium experiments are used to identify all possible climatic conditions producing stable glaciers at the positions marked by the moraines and historical ice limit. Relative to the 1985-2015 CE climatic baseline, results suggest that valley temperatures were 2.9-1.9˚C cooler at 10.8ka BP and at least 1.0˚C cooler at 9.4ka BP. Proximity between the 9.6ka and 6.2ka moraines makes their climatic signatures difficult to distinguish. Finally, the equilibrium experiment confirms that in 1962 the glacier was already far out of balance. In summary, this thesis presents a data-intensive approach to improving model performance on a tropical glacier, enabling accurate ice loss projections, and helping to constrain paleoclimatic interpretations of tropical glacier geomorphology.

Committee: Bryan Mark (Advisor); Zhengyu Liu (Committee Member); Ellen Mosley-Thompson (Committee Member) Subjects: Geography; Geomorphology

Doctor of Philosophy (PhD), Ohio University, 0, Instructional Technology (Education)

At a time when the world is facing a range of significant challenges, including a rise in air temperature, rapidly evolving droughts in some areas, and floods, new technology in education can help inform people of current issues that may not be close to them but, nevertheless, can have a significant impact in the future. Our planet has been warming steadily for over a century, and the preponderance of evidence has pointed at human action as the main contributor to the change (Hansen et al., 2010). The evolution of technology has brought tremendous change. Virtual Reality (VR), 360-degree video, has the potential to bring the environment to the students since it can provide a close to a real-life situation. The use of VR for educational purposes has been quite unknown to most school systems. There are many gaps that need to be investigated prior to the effective implementation of VR-learning, such as the factors that influence students' intention to use it. This study fulfilled some of these gaps by focusing on the potential of using VR for future education and raising awareness of the climate change occurring in remote areas, specifically tropical regions. The findings of this study will hopefully encourage students to play a more responsible role in the development and implementation of VR education worldwide and help enhance the academic quality of courses for instructors and students. This study examined students' behavioral intentions towards using VR in their learning about climate change utilizing the Technology Acceptance Model of Davis (1989), combined with the spatial presence experience scale (Hartmann et al., 2015). Phase 1 was created in order to understand students' salient beliefs about the use of VR for educational purposes and learning about climate change. Furthermore, 65 students participated in this phase and reported that VR can be beneficial for educational purposes to learn about global climate change, and 95.2% of participants fully agreed. Ph (open full item for complete abstract)

Committee: Greg Kessler (Advisor); Gordon Brooks (Advisor) Subjects: Climate Change; Educational Technology; Environmental Education

Doctor of Philosophy, The Ohio State University, 2020, Earth Sciences

The Greenland Ice Sheet (GrIS) is losing mass at accelerated rates in the 21st century, due in part to faster flow at large outlet glaciers. Chapter 2 presents work published in The Cryosphere (King et al., 2018). Here, we sample rapid changes in thickness and velocity at all large outlet glaciers to derive the first continuous, GrIS-wide record of total ice sheet discharge, or the volume of ice glaciers export, for the 2000-2016 period. We resolve a distinct pattern of seasonal variability with an amplitude of 6%, and analyze how seasonal to annual variability in the discharge time series relates to both meltwater runoff and glacier front position changes over the same period. We find that the annual magnitude of discharge is closely related to cumulative front position change (r2 = 0.79), averaging over 2 km of retreat since 2000. We find that larger seasonal quantities of runoff do not relate to increased annual discharge, although seasonal acceleration of ice discharge does closely coincide with the onset of the melt season. These results suggest that changes in glacier front position drive secular trends in discharge, whereas the impact of runoff is likely limited to the summer months when observed seasonal variations are substantially controlled by the timing of meltwater input. In Chapter 3, we extend our 2000-2016 discharge time series to the period 1985-2018, combining more than three decades of GrIS-wide observational products of outlet glacier velocity, elevation, and front position changes, and compare decadal variability in discharge with calving front position. We find that the close relationship between frontal change and ice discharge identified over the 2000-2016 record holds true for the 34-year record, and that increased glacier discharge can be attributed almost entirely to the retreat of glacier fronts, rather than inland ice sheet processes, such as changes in meltwater runoff. Discharge sensitivity to retreat is remarkably consistent across (open full item for complete abstract)

Committee: Ian Howat (Advisor); Lonnie Thompson (Committee Member); Michael Durand (Committee Member); Bryan Mark (Committee Member) Subjects: Climate Change; Earth; Environmental Studies; Geological; Geophysical; Geophysics

Master of Science, The Ohio State University, 2019, Earth Sciences

The margins of the greenland ice sheet are the leading contribution to global sea level rise, and changes have been noted at many of its marine terminating outlet glaciers. Here we present changes in the rates of surface elevation change along the entire margin of the Greenland ice sheet at 205 marine terminating glaciers between 1978 and 2015. We analyzed an assemblage of multiple surface elevation data sets to assess how rates of surface elevation change are changing at these glaciers. We find that the change in rates of surface elevation loss have increased by 150% to 300% since pre-2000 rates into the 2000's, following by a 10% to 20% slowdown in current times. We find that these modern rates are significantly different from historic rates, suggesting that current forcings are changing the ice loss mechanics of the GrIS in the 21st century.

Committee: Ian Howat Ph.D (Advisor); Michael Durand Ph.D (Committee Member); C.K. Shum Ph.D (Committee Member) Subjects: Climate Change; Earth

Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects: Mathematics

Doctor of Philosophy, The Ohio State University, 1981, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1980, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1976, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1976, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1975, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1973, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1972, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1967, Graduate School

Committee: Not Provided (Other) Subjects: Geology

Doctor of Philosophy, The Ohio State University, 1969, Graduate School

Committee: Not Provided (Other) Subjects: Geophysics

Doctor of Philosophy, The Ohio State University, 1969, Graduate School

Committee: Not Provided (Other) Subjects: Geology