This dissertation work applies seismic tomographic inversion methods to two different datasets - one to address the earthquake hazard within the Strait of Georgia and the other to estimate hydrate concentration and distribution in the continental slope off Vancouver Island. In the first part of the study, seismic refraction/wide-angle reflection data from onshore-offshore experiments in 1998 and 2002 were inverted for a smooth three-dimensional (3D) velocity structure down to depths of 6-7 km beneath the Strait of Georgia, a seismically active region where an earthquake swarm (with magnitude up to 5) occurred in 1995-1997. The objectives were to map structures that contribute to seismic hazard evaluation in the Georgia Basin. The main structural features obtained from the inversion are: a northeast-southwest trending hinge line at the location of the earthquake swarm, where the basin deepens rapidly to the southeast; a northwest-southeast trending velocity discontinuity that correlates well with the surface expression of the shallow Outer Island fault; sediment thickening from north to south; and basement uplift at the San Juan Islands, possibly caused by a thrust fault. In the second part of the dissertation, seismic single channel and wide-angle reflection data collected in September 2005 were analyzed for a 2D profile of ocean bottom seis¬mometers (OBSs) on the continental slope region off Vancouver Island, near ODP Site 889 and IODP Site 1327. The objectives were to determine the shallow sediment velocity structure associated with marine gas hydrates and to estimate the hydrate concentration in the sediment pore space. Combined inversion of single channel and OBS data produced a P-wave velocity model down to the depth of the BSR at 230 m below seafloor. Strong attenuation of P-waves below the BSR indicates the presence of free gas. To investigate structures below the BSR, forward modelling of S-waves was carried out using the data. from the OBS horizontal components. Both the P- and S-wave models match very well with the sonic log data from ODP Site 889 and IODP Site 1327. The increase in P-wave velocity of the hydrate bearing sediments relative to the background no-hydrate velocity was utilized to estimate the hydrate concentration by using a simple porosity-reduction equation. An average concentration of 15% was estimated from the P-wave velocity model. Prestack depth migration was applied to the OBS data to image the structure along the 2D profile containing the OBSs. The primary and multiple arrivals were migrated separately. Conventional migration of the primary arrivals produced an image with a very narrow illumination and the shallow subsurface layers including the seabottom were not imaged. However, migration of the OBS multiples, using a mirror imaging technique, pro¬duced a continuous structural image of the subsurface including the shallowest layers. The lateral illumination is much wider with a quality comparable to that of vertical incidence reflection data.

Conservation of biodiversity is a major issue in ancient temperate rainforests of British Columbia. While significant efforts have been made to document species of birds and mammals, little is known about canopy arthropod communities in British Columbia. Microhabitats (suspended soils) within canopy systems of temperate rainforests support diverse microarthropod communities, dominated by mites of the suborder Oribatida. These oribatid mite communities are distinct from forest floor communities, contribute significantly to overall forest biodiversity, and are functionally important components of forest ecosystems. I used the suspended soil system in western redcedar trees in the Walbran Valley to study the relative importance of local environmental factors versus regional spatial factors contributing to the structure of arboreal oribatid mite communities. and compare these patterns to forest floor oribatid mite communities at the same study location. An array of sampling methods was used to complete these objectives: substrate core samples. bark scrapings, colonisation of litterbags, litterfall collection, and colonisation of artificial canopy habitats. This study identified 138 species of oribatid mites associated with ancient western redcedar trees of the Walbran Valley on Vancouver Island. The documented patterns of oribatid mite diversity in this rainforest demonstrated higher local species richness (alpha diversity) in terrestrial (forest floor) habitats, and greater beta diversity in arboreal (suspended soil) habitats. The oribatid mite community within suspended soils are formed primarily by dispersal patterns and colonisation within the canopy system. with limited colonisation from the forest floor. The factors, which shape canopy oribatid mite communities within suspended soils, are related to habitat availability, moisture limitation and random dispersal events of individual species. My results suggest the arboreal oribatid mite community experiences regional dispersal limitation associated with physical tree-to-tree dispersal barriers. However, factors other than physical dispersal barriers. such as aggregation and niche partitioning, likely also limit the local distribution of species in both arboreal and terrestrial habitats. Stochastic dispersal dynamics within the canopy are crucial to understanding oribatid mite community structure in suspended soils. yet the relative importance of regional dispersal processes is dependent on deterministic factors relating to the environmental tolerances of individual species at the local scale.

Regenerating haa-huu-pah is necessary for the development of a vision of self-determination, and the reclamation of land and freedom for Indigenous peoples. Tla-o-qui-aht and Checlesaht are Indigenous nations who recognize the need for an alternative to colonial processes and have begun looking for strategies for regenerating Quu'asminaa governance. Quu'asminaa leaders, called 'hawiih' (respected and knowledgeable people). were. and in some families continue to be, groomed from an early age to uphold their specific responsibilities. These responsibilities are both personal and collective and include adhering to the laws of the hahuuthlii (the territories, including land, sea. mountains and sky), as well as accountability to the muschim. Hawiih are taught these responsibilities through haa-huu-pah, which are the re-telling of stories, teachings, and ways of our people. Today, utilizing haa-huu-pah is vital to the regeneration of Quu'asminaa governance and to building strong movements toward self-determination within Indigenous communities.

In order to set guidelines that promote responsible wildlife viewing, I quantified the effects of boat-based disturbance to seabirds off Vancouver Island. Field trials recorded the approach distance at which roosting and nesting birds responded to either a motor boat or a kayak. Probability of agitation response was used to evaluate disturbance. At a distance of 40 m nesting Double-crested Cormorants, Pelagic Cormorants, Glaucous-winged Gulls, Pigeon Guillemots and Black Oystercatchers had less than an 8% chance of being agitated with either a kayak or motorboat approach. Roosting birds had longer response distances. Harlequin Ducks were particularly sensitive with a 25% probability of agitation at distances less than 50 m. Agitation distances were reduced by habituation to boat traffic. A set-back guideline of 50 m would protect most nest and roost sites in the study area while allowing viewers to appreciate seabirds. Some sensitive sites would require 70 m set-backs.

The geology, petrology and geochemistry of Catface porphyry Cu (Mo-Au) deposit, located on the west coast of Vancouver Island are examined in detail. Detailed core logging and sampling was carried out to characterize the geometry and identity of different intrusive phases and alteration styles prevalent during the emplacement and formation of the deposit, as well as their geochemical affinity. Early- and late-stage potassic alteration is identified, as well as main-stage sodic-calcic and calcic-sodic alteration. Four distinct Paleogene intrusive phases vary from quartz diorite to granodiorite in composition. The rocks are broadly calc-alkaline, weakly peraluminous to moderately metaluminous, and have typical arc geochemical affinity. The timing of emplacement and mineralization is constrained by U-Pb and Re-Os geochronology at 40.4-41.4 Ma and 40.9 ±0.2 Ma, respectively. All four Paleogene Catface intrusive phases were emplaced close in time with a direct temporal correlation to mineralization. The chalcopyrite- and pyrite-bearing miarolitic cavities in the Halo Porphyry intrusive, combined with U-Pb and Re-Os dates suggest this intrusive phase is the most likely source of mineralizing fluids. The intrusions were emplaced at depths of less four kilometers in the crust, as evidenced by the presence of miarolitic cavities and confirmed through amphibole-plagioclase thermobarometry, which record conditions of 615–700 °C and <200 MPa. The lack of primary anhydrite and hematite, and the presence of pyrrhotite in the ore system indicate a reduced magmatic-hydrothermal event. The SO3 contents in apatites are <450 ppm, indicative of a degassed and/or sulphate-free (reduced) magma. The assemblage K-feldspar-quartz-biotite-ilmenite yields oxygen fugacities (fO2) which are 0.5 to 3.0 log units below the quartz-fayalite-magnetite (QFM) buffer at an assumed pressure of 300 MPa; orders of magnitude more reduced than typical porphyry deposits. Parental magmas to the Catface deposit were either derived from intrinsically-reduced mantle, or more typical oxidized arc magma that was subsequently reduced during ascent and emplacement. Further isotopic work is required to determine which process contributed to the reduction of these magmas in an arc setting. Nevertheless, recognition of reduced porphyry-related magmatism on west-central Vancouver Island is of similar age to that of North Fork (~36.8-38.9 Ma) deposit in Washington suggesting a consanguinity of reduced magmatism with the Paleogene Cascade arc. / Graduate