Using Spectral Analysis and Fluid Dynamics to Understand Supraglacial Stream Networks on the Greenland Ice Sheet and Seismicity at Kilauea Volcano
| dc.contributor.advisor | Karlstrom, Leif | |
| dc.contributor.author | Crozier, Josh | |
| dc.date.accessioned | 2021-09-13T18:37:05Z | |
| dc.date.available | 2021-09-13T18:37:05Z | |
| dc.date.issued | 2021-09-13 | |
| dc.description.abstract | Fluid dynamics are an integral component of many natural systems considered in earth sciences, including both ice sheets and volcanoes. I combine fluid dynamics modeling with multiple spectral analysis techniques and a variety of datasets to address questions in glaciology and volcanology. I first examine what controls supraglacial meltwater routing on the Greenland Ice Sheet, and how this meltwater routing respond to changing ice sheet conditions. I approach this with fluid dynamical models of ice flow and multiple geomorphologial methods based on spectral analysis. I demonstrate that bedrock topography underlying the ice sheet is the dominant control on supraglacial drainage basin scale ice surface topography and meltwater routing. I then show that a thinning ice sheet or increasing basal sliding will result in smaller supraglacial drainage basins. This could cause more disperse subglacial meltwater input and potentially further impact ice sheet flow, so may be important to incorporate into ice sheet evolution models. I next examine what very long period seismicity from magma resonance can reveal about evolution of the shallow magma system at Kilauea Volcano. To do this I develop a new automated workflow for detecting and classifying resonant signals based on wavelet transforms. I then create a catalog of very long period seismicity over the 2008-2018 summit eruption of Kilauea Volcano. To analyze this catalog, I develop a coupled fluid-elastic model for the magma resonance. This model includes empirically constrained models for magma properties, joint H2O-CO2 solubility relationships, and accounts for stratified magma columns that could arise under disequilibrium outgassing regimes. I then conduct inversions for the seismic catalog, with constraints from other geophysical data and inversions. These inversions yield an unprecedented in-situ resolution of changes over time in both magma temperature and volatile contents. They show evolution of the magma system over a variety of timescales, and provide insights with implications for both hazard monitoring and understanding volcanic processes. This dissertation includes previously published and unpublished co-authored material. | en_US |
| dc.identifier.uri | https://hdl.handle.net/1794/26634 | |
| dc.language.iso | en_US | |
| dc.publisher | University of Oregon | |
| dc.rights | All Rights Reserved. | |
| dc.title | Using Spectral Analysis and Fluid Dynamics to Understand Supraglacial Stream Networks on the Greenland Ice Sheet and Seismicity at Kilauea Volcano | |
| dc.type | Electronic Thesis or Dissertation | |
| thesis.degree.discipline | Department of Geological Sciences | |
| thesis.degree.grantor | University of Oregon | |
| thesis.degree.level | doctoral | |
| thesis.degree.name | Ph.D. |
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