267. Corti, Giovanni.Detection and Characterization of Discontinuous Motion on Thompson Glacier, Canadia High Arctic, Using Speckle Tracking, and Ice-Flow Modeling.Supervisor: Flowers; Rabus, 2022, Detection and Characterization of Discontinuous Motion on Thompson Glacier, Canadia High Arctic, Using Speckle Tracking, and Ice-Flow Modeling
Synthetic aperture radar, arctic glacier, speckle tracking, discontinuous motion, finite-element modelling
High resolution Synthetic Aperture Radar (SAR) data allow for measurement of multicentimeter-scale glacier motion via a technique known as speckle tracking. In this thesis, I develop an intensity rescaling that improves the performance of speckle tracking and use it to quantify an uncommon form of discontinuous glacier motion, where velocity differences up to 1 cm/d occur across large supraglacial stream channels on Thompson Glacier, Umingmat Nunaat (Axel Heiberg Island), Canadian High Arctic. The intensity rescaling is developed using simulated SAR data and results in a 20% performance improvement. Cross-sectional ice-flow modeling indicates that the discontinuous motion observed can occur without ice fracture and under a wide variety of glacier thermal conditions. This form of cross-channel discontinuous motion is likely uncommon as it requires channels that are sufficiently deep, located in regions of substantial shear stress and that are aligned with shear stresses over substantial spatial scales.SFU Download
204. Whistler, Allegra.Investigating the Thermo-Hydraulic Regime of Union Creek, Langley B.C., 2018, Investigating the Thermo-Hydraulic Regime of Union Creek, Langley B.C.
Undergraduate Honour's Thesis: Stream thermal regime; hydraulic connectivity; aquifer-stream interaction;
groundwater abstraction; pumping test; thermal infrared imaging
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174. Roberts, Nick.Late Cenozoic geology of La Paz, Bolivia, and its relation to landslide activity.Supervisor: Clague, 2016, Late Cenozoic geology of La Paz, Bolivia, and its relation to landslide activity
Andean landscape evolution; Paleomagnetism; Pliocene tropical glaciation; Landslide inventory; Urban landslide hazard and risk; Homogeneous Distributed Scatterer Synthetic Aperature interferometry (HDS-InSAR), Thesis
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165. Hamdi, Pooya.Characterization of Brittle Damage in Rock from the Micro to Macro Scale.Supervisor: Stead, 2015, Characterization of Brittle Damage in Rock from the Micro to Macro Scale
Brittle fracture, numerical modelling, combined finite/discrete element method (FDEM), Discrete fracture network (DFN), sub level caving, subsidence, Thesis
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133. Heideman, Marit.Flood hazard and risk in Lillooet River valley, British Columbia.Supervisor: Clague, 2013, Flood hazard and risk in Lillooet River valley, British Columbia
Varves; Sediment yield; Flooding;Natural hazards; Lillooet River valley, British Columbia; Knowledge transfer; Society-science relationships; Flood management, Thesis
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103. Schon, Peter.Stability and Mechanism of Failure of the Barrier, Southwest British Columbia.Supervisor: Clague, 2011, Stability and Mechanism of Failure of the Barrier, Southwest British Columbia
The Barrier; Landslide; Rock fall; Garibaldi Provincial Park; Pleistocene; Magnetic survey; Photogrammetry; Survey; UDEC; Geophysics; Modelling; Distinct element code; Voronoi; Tessellation; Ice-contact volcanism, Thesis
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102. Shugar, Dan.Rock avalanches on glaciers.Supervisor: Clague, 2011, Rock avalanches on glaciers
Rock avalanche; Landslide; Geomorphology; Glaciology; Climate change; Natural hazards; InSAR; Radar speckle tracking; Black Rapids Glacier; Sherman Glacier; Alaska, Thesis
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82. Wheler, Brett.Glacier melt modelling in the Donjek Range, St. Elias Mountains, Yukon Territory.Supervisor: Flowers, 2009, Glacier melt modelling in the Donjek Range, St. Elias Mountains, Yukon Territory
Glaciology; Glaciers -- Yukon Territory; Glaciers; Mountain climate; Temperature-index modelling; Energy balance; Surface temperature; St. Elias Mountains;Glacier mass-balance; Regional modelling, Thesis
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79. Kowalchuk, Chris.Quaternary Geology of the Zama City Area, Northwestern Alberta.Supervisor: Ward, 2008, Quaternary Geology of the Zama City Area, Northwestern Alberta
Geology Alberta, Geology, Stratigraphic Quaternary; Geology Alberta Maps; Geology, Stratigraphic Pleistocene; Laurentide glaciation; Quaternary; Stratigraphy; NTS 84M; Fort Nelson Lowland; Alberta; Glacial lakes, Thesis
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73. Turner, Derek.Quaternary Geology of Howard's Pass and Applications to Drift Prospecting.Supervisor: Ward, 2008, Quaternary Geology of Howard's Pass and Applications to Drift Prospecting
Geology Yukon Territory - Selwyn Mountains Maps; Geology, stratigraphic … Quaternary; Prospecting … Yukon Territory … Selwyn Mountains; Geology … stratigraphic … Yukon Territory; Drift prospecting; Quaternary stratigraphy; Ice-flow history; Terrain mapping; MMI geochemistry; Cosmogenic nuclides, Thesis
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72. Vyazmensky, Alexander.Numerical modelling of surface subsidence associated with block cave mining using a finite element/discrete element approach.Supervisor: Stead, 2008, Numerical modelling of surface subsidence associated with block cave mining using a finite element/discrete element approach
Rock Mechanics; Rock mechanics -- Research; Rocks Fracture; Mining engineering ;Mines and mineral resources -- Research; Mine subsidences; Rock mechanics; Numerical modelling; Block cave mining; Block caving subsidence; Open pit - caving mining interaction
FEM/DEM-DFN, Thesis
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11. Williams-Jones, G.Integrated Geophysical Studies at Masaya Volcano, Nicaragua.Ph.D. Thesis, The Open University, UK., 2001, 237 Integrated Geophysical Studies at Masaya Volcano, Nicaragua.
Research into the mechanisms responsible for the lasting, cyclic activity at Masaya volcano can lead to a better understanding of persistently degassing volcanoes. This study is greatly enhanced by the integration of dynamic micro-gravity, deformation and gas flux measurements. The acquisition of extended temporal and spatial geophysical data will also allow for the development of robust models for the dynamics of magmatic systems. Masaya volcano, Nicaragua, is one of the most active systems in Central America, making it an excellent natural laboratory for this study. It is noted for repeated episodes of lava lake formation, strong degassing and subsequent quiescence.
Ground-based geophysical measurements show two episodes of similar magnitude gravity decreases in 1993-1994 and 1997-1999, separated by a period of minor gravity increase. A major increase in SO2 gas flux from 1997-1999 correlates well with the most recent episode of gravity decrease. The gravity changes are not accompanied by deformation in the summit areas and are interpreted in terms of sub-surface density changes. The persistent degassing at Masaya suggests that up to ~15 km3 of magma may have degassed over the last 150 years, only a minute fraction of which has been erupted. Furthermore, thermal flux calculations suggest that 0.5 km3 of magma (the estimated volume of the shallow reservoir) would cool from liquidus to just above solidus temperatures in only 5 years. The high rates of degassing and cooling at open-system volcanoes such as Masaya raise questions as to the ultimate fate of this degassed and cooled magma. A number of models have been proposed to explain this, but the most likely mechanism to explain persistent activity at Masaya and other similar volcanoes is convective removal of cooled and degassed magma and subsequent recharge by volatile-rich magma from depth.
Another fundamental question in modern volcanology concerns the manner in which a volcanic eruption is triggered; the intrusion of fresh magma into a reservoir is thought to be a key component. The amount by which previously ponded reservoir magma interacts with a newly intruded magma will determine the nature and rate of eruption as well as the chemistry of erupted lavas and shallow dykes. The physics of this interaction can be investigated through a conventional monitoring procedure that incorporates the Mogi model relating ground deformation (∆h) to changes in volume of a magma reservoir. Gravity changes (∆g) combined with ground deformation provides information on magma reservoir mass changes. Models developed here predict how, during inflation, the observed ∆g/∆h gradient will evolve as a volcano develops from a state of dormancy through unrest into a state of explosive activity.
1. Williams-Jones, G.The Distribution and Origin of Radon, CO2 and SO2 Gases at Arenal Volcano, Costa Rica.M.Sc. Thesis, Université de Montréal, 1996, 135 The Distribution and Origin of Radon, CO2 and SO2 Gases at Arenal Volcano, Costa Rica.
Volcanic gases are one of several important indicators used to better understand and forecast volcanic activity. However, direct sampling of these gases is often dangerous or impossible due to the high level of activity and the common inaccessibility of the crater areas of many volcanoes. Indirect methods such as the study of soil gases or the use of remote sensing techniques are thus required. Soil gases such as radon and carbon dioxide have been shown to correlate well with variations in volcanic activity. Similarly, the remote sensing of gases such as sulphur dioxide has proven significant in the geochemical characterisation of both passively and actively degassing volcanoes. Techniques such as these can now provide important clues to the behaviour and future
activity of the volcano.
This thesis investigates the degassing of Arenal volcano. A small stratovolcano in northwestern Costa Rica, Arenal is one of the most active volcanoes in Central America, having been in continuous eruption since its reactivation in July 1968. Estimates, using petrologic and remote sensing techniques, are made of the quantity of SO2 emitted from Arenal since 1968 and are related to a degassing model for the volcano. Observed spatial and temporal patterns of soil and plume gases are correlated to eruptive and seismic activity, and the origin and transport of these gases at Arenal is discussed. Measurements of seismicity, radon, CO2 and SO2 gas were made as (1) the results could be compared to other volcanoes where similar measurements have been
made, (2) it was comparatively simple to measure radon, CO2, and SO2, and (3) these gases are believed to respond to changes in activity and the stress-state of the volcano.
