Earth Sciences - Theses, Dissertations, and other Required Graduate Degree Essays

Receive updates for this collection

Objective preliminary assessment of outburst flood hazard from moraine-dammed lakes in southwestern British Columbia

Date created: 
2005
Abstract: 

An objective, remote sensing-based procedure is proposed to evaluate the outburst flood hazard posed by moraine-dammed lakes in southwestern British Columbia. Outburst probability is estimated using an expression derived from statistical analysis of data collected from 175 moraine-dammed lakes in the southern Coast Mountains. Logistic regression identified four factors that correctly discriminate 70% of drained and 90% of undrained lakes: moraine height-to-width ratio, presencelabsence of an ice core in the moraine, lake area, and main rock type forming the moraine. Objective methods, which incorporate empirical relations applicable to the study region, are used to predict outburst peak discharge and debris flow volume, travel distance, and area of inundation. Outburst flood hazard is especially sensitive to lake level fluctuations and is greatest for large lakes perched on valley sides behind narrow, ice-free moraine dams composed of sedimentary rock debris.

Document type: 
Thesis
File(s): 
Department: 
Department of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Occurrence and genesis of alpine linears due to gravitational deformation in South Western British Columbia

Author: 
Date created: 
2004
Abstract: 

Alpine linears are found on many slopes in south western, British Columbia. The genesis of these features is commonly related to gravitational deformation of rock slopes. A preliminary stress analysis of selected ridge morphologies indicates that the resulting stress fields are different for each basic ridge type analysed, indicating that various deformation mechanisms may be active in producing alpine linears. An integrated system of GIs and numerical modelling is applied to a study of Mount Mercer, British Columbia. Detailed geomorphic and engineering geological mapping indicates that linears observed along the ridgeline of Mount Mercer are due to rock slope deformations. Potential failure mechanisms are evaluated for kinematic feasibility and resulting failure morphology. The results of the study indicate that toppling does not appear to be a suitable rock mass deformation mode for the failures at Mount Mercer; bi-planar failure and rock slumping are demonstrated to be suitable for the rock slope failures.

Document type: 
Thesis
File(s): 
Department: 
Department of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Quaternary stratigraphy and geologic history of the Charlie Lake (NTS 94A) map-area, British Columbia

Author: 
Date created: 
2005
Abstract: 

Two Cordilleran and three Laurentide glacial advances are recorded by Quaternary sediments in the Charlie Lake map-area (NTS 94A). The advances are inferred from the presence of exotic clasts derived from the Canadian Shield, fluvial deposits, glaciolacustrine deposits, and tills within nested paleo-valleys excavated during three interglaciations. The Late Wisconsinan Laurentide glaciation was the most extensive Laurentide glaciation, and the only one recognized in western Alberta south of the study area. Coalescence of Late Wisconsinan Laurentide and Cordilleran Ice Sheets is not recognized within the study area. Advancing Late Wisconsinan Laurentide ice blocked the east-flowing drainage and impounded Glacial Lake Mathews within paleo-Peace River valley and its tributaries. More than 100 m of fine sediment, deposited by suspension settling and density underflows were deposited in the centre of the basin. Weak, plastic clay layers within the glaciolacustrine sequence have developed shear planes on which more than 900 landslides have occurred.

Document type: 
Thesis
File(s): 
Department: 
Department of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Historical climate variability from the instrumental record in northern British Columbia and its influence on slope stability

Date created: 
2005
Abstract: 

This thesis examines historical climate variability and its effects on slope stability in northern British Columbia. It comprises three parts: (1) an analysis of climate trends and variability from the instrumental climate record; (2) an examination of climate controls on historic, large landslides; and (3) a demonstration of the utility of weather satellite imagery in determining landslide triggers. The climate of northern British Columbia has become wetter and warmer since the beginning of instrumental observations. Documented trends are complex due to ocean-atmosphere oscillations such as the Pacific Decadal Oscillation and the El Niiio Southern Oscillation. Long periods of increasing precipitation and temperature are a~~sociated with most dated, large landslides in the study area. Convective storms, large c:yclonic storms, and other weather events commonly trigger slope failure. Weather satellite images facilitated the analysis of climate triggers of landslides in remote areas and at high elevations.

Document type: 
Thesis
File(s): 
Department: 
Department of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

The influence of tectonic structures on rock mass quality and implications for rock slope stability

Date created: 
2005
Abstract: 

A field, laboratory and numerical modelling methodology was developed to investigate the influence of tectonic structure on rock mass quality and implications for rock slope stability. The fundamental components of this methodology include a full description of the rock mass (GSI, number of joint sets, block size and shape, weathering) and discontinuities (orientation, surface roughness, spacing, persistence, infill, seepage) in all accessible sections of the landslide, laboratory work (point load testing and thin section descriptions), and numerical modelling (limit equilibrium, finite difference and distinct element). Detailed fieldwork performed at the Aishihik River landslide, Hope Slide, and East Gate Landslide showed that pre-existing tectonic structures can significantly reduce the rock mass quality and facilitate the development of release surfaces. Numerical models of conceptual and natural slopes have shown that different representation of faults and related damage zone has a significant influence on the shape, volume, and failure mechanism of a landslide.

Document type: 
Thesis
File(s): 
Department: 
Department of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Three-dimensional kinematic controls on rock slope stability conditions

Date created: 
2010
Abstract: 

This thesis investigates the three-dimensional influence of discontinuity sets and topography on kinematics of rock slope stability and failure mechanisms. A field data collection methodology was developed to provide the inputs to a slope stability investigation that utilises three-dimensional geometric, limit equilibrium and distinct element codes. Conceptual slope geometries in addition to three case studies are employed to evaluate the influence of discontinuity set orientation and lateral kinematic confinement on the failure mechanism and slope stability conditions. The influence of varying the discontinuity persistence and block size in a three-dimensional distinct element code are also investigated. Systematic studies of these parameters are performed for the planar sliding and block toppling failure mechanisms. This thesis presents the first detailed description and slope stability analysis of the McAuley Creek Landslide and the Chehalis Lake Landslide. New data and analyses of the potentially unstable rock mass at Third Peak on Turtle Mountain are also presented. Two recently developed representations of complex topography in the three-dimensional distinct element code are applied to the case studies. The results obtained in this thesis are compared to the description of other local and international large rock slope failures published in the literature.

Document type: 
Thesis
File(s): 
Senior supervisor: 
D
Department: 
Department of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (Ph.D.)

Conuma River and Leagh Creek intrusive complexes: windows into mid-crustal levels of the Jurassic Bonanza island arc, Vancouver Island, British Columbia

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009
Abstract: 

The Conuma River and Leagh Creek intrusive complexes are examples of mid-crustal portions of the Jurassic Bonanza island arc, located on Vancouver Island, British Columbia, Canada. The Conuma River locality exhibits layered intrusions, consisting of alternating hornblenditic and hornblende gabbroic cumulates, occurring with numerous, contemporaneous small volume mafic to intermediate intrusions in tonalitic rocks. The Leagh Creek intrusions exhibit extensive silicic and basaltic magma mingling. Both complexes are interpreted as products of multiple magma pulses into the solidifying host intrusions. Two new radiometric hornblende Ar-Ar ages suggest Early to Middle Jurassic ages for two intrusions from each of the complexes. Geochemical crystallization modeling shows a genetic link between the Conuma River cumulate hornblenditic and non-cumulate hornblende gabbroic intrusions via dominantly olivine fractionation. Conversely, most of the intrusions of both complexes cannot be related by simple crystallization modeling, suggesting a complex history, involving magma mingling and assimilation processes.

Document type: 
Thesis
File(s): 
Senior supervisor: 
D
Department: 
Dept. of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Multi-scale analysis of multiparameter geophysical and geochemical data from active volcanic systems

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009
Abstract: 

Persistently active volcanoes present short and long term variation in their magmatic, hydrothermal, and/or hydrogeological systems. As magma is rarely accessible on the surface, investigation of the dynamic behaviour of the hydrothermal system is an indirect approach to study the underlying magmatic activity. Variations in volume, mass and flow direction of the water are expressed through change and generation of local disturbances of potential-fields, such as gravity or Self-potential. The source generating the potential-field signal is a non-unique solution, making it very difficult to model. This study uses a modern signal analysis technique, Multi-scale wavelet tomography, to accurately determine the depths of these sources. The accuracy of Multi-scale wavelet tomography on Self-potential data was tested on three volcanoes (Masaya, Stromboli, Waita) in comparison with water depths calculated by more traditional geophysical methods. Traditional inverse gravity modeling is also used to better constrain the non-unique solution of potential-fields. This study also investigates two persistently active volcanoes, Masaya and Kawah Ijen, through time-series and spatial surveys to monitor change occurring within them. This study shows that a well established and mature hydrothermal system can show limited surface expression as at Kawah Ijen volcano, while an apparently low intensity hydrothermal system can have an extensive and complex system beyond its active crater, such as at Masaya volcano. The hydrothermal system of Masaya is spatially controlled by a ring fault structure and has been stable between 2006 and 2009. In contrast, on Kawah Ijen, the intense and well-established hydrothermal system is completely self-sealed within the upper volcanic edifice and can only release the pressurized fluids and gas through the active crater. Nevertheless, between 2006 and 2008, the hydrological system showed significant vertical change due to seasonal effects. By integrating a wide variety of distinct, complementary techniques to a number of persistently active volcanoes, over an extended period of time, it is possible through accumulation of baseline information, to characterize the components of signals detected on volcanoes. A more accurate understanding of the volcanic system as a whole, through accurate constraint of the different volcanic signals, is fundamental in improving volcano monitoring and hazard mitigation.

Document type: 
Thesis
File(s): 
Senior supervisor: 
G
Department: 
Dept. of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (Ph.D.)

Sedimentology, stratigraphy, and provenance of the Lower Cretaceous Jackass Mountain Group, Chilko Lake area, British Columbia, Canada

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009
Abstract: 

The Cretaceous Jackass Mountain Group (JMG) near Chilko Lake in south central British Columbia is an approximately 2 km-thick, shallow-marine succession composed of immature, volcanic-rich sandstone, with subordinate mudstone and conglomerate. Deposition of the JMG occurred within the Methow Basin along the western margin of North America, over the accreted Cadwallader, Bridge River and Methow Terranes. Four facies associations represent sedimentation during Albian to Cenomanian time, and are characterized by nearshore and deltaic deposits that accumulated in close proximity to an active volcanic arc system and older uplifted volcanoplutonic arc rocks. Correlation between disparate Cretaceous sedimentary packages was tested by petrographic, geochemical, and detrital zircon analyses. These analyses indicate that the Chilko Lake and the Camelsfoot Range JMG, now offset across the Yalakom Fault, are correlative; however, a direct correlation to the Taylor Creek Group of the Tyaughton Basin remains tenuous.

Document type: 
Thesis
File(s): 
Senior supervisor: 
J
Department: 
Dept. of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)

Evaluation of subaerial landslide hazards in Knight Inlet and Howe Sound, British Columbia

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009
Abstract: 

This thesis evaluated hazards from subaerial (originating above sea level) landslide-induced tsunamis in Knight Inlet and Howe Sound. Field assessments were conducted at Adeane Point and Mount Gardner. GIS was used at site and inlet scales to compile existing map data, to map submarine slide deposits, to measure topographic parameters, and to integrate observations. Modelling at Adeane Point employed kinematic, limit equilibrium (SWEDGE) and discrete element (3DEC) analyses in order to estimate the volume of a potential landslide. Results suggest that the hazard from subaerial slide-induced waves is high in Knight Inlet, particularly in the area between Adeane Point and Glacier Bay, whereas, when compared with Knight Inlet, the hazard in Howe Sound appears considerably less. Modelling results suggest that topography and discontinuity persistence are the leading controls on failure volume. A preliminary catalogue of techniques for assessing hazards from slide waves was created, and related issues were discussed.

Document type: 
Thesis
Senior supervisor: 
D
Department: 
Dept. of Earth Sciences - Simon Fraser University
Thesis type: 
Thesis (M.Sc.)