946 resultados para Hypoxia (water) - British Columbia - Nootka Sound - Muchalat Inlet
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Senior thesis written for Oceanography 445
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Concretions of iron and manganese oxides and hydrous oxidesóobjects commonly called manganese nodulesóare widely distributed not only on the deep-sea floor but also in shallow marine environments1. Such concretions were not known to occur north of Cape Mendocino in the shallow water zones bordering the North-East Pacific Ocean until the summer of 1966 when they were recovered by one of us (J. W. M.) in dredge samples from Jervis Inlet, a fjord approximately 50 miles north-west of Vancouver, British Columbia.
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Thesis written for Oceanography 445
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Senior thesis written for Oceanography 445
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A study of the distribution, dispersal and composition of surficial sediments in the Strait of Georgia, B.C., has resulted in the understanding of basic sedimentologic conditions within this area. The Strait of Georgia is: a long, narrow, semi-enclosed basin with a restricted circulation and a single, main, sediment source. The Fraser. River supplies practically all the sediment now being deposited in the Strait of Georgia, the bulk of it during the spring and summer freshet. This river is building a delta into the Strait from the east side near the south end. Ridges of Pleistocene deposits within the Strait and Pleistocene material around the margins, like bedrock exposures, provide local sources of sediment of only minor importance. Rivers and streams other than the Fraser contribute insignificant quantities of sediment to the Strait. Sandy sediments are concentrated in the vicinity of the delta, and in the area to the south and southeast. Mean grain size decreases from the delta toward the northwest along the axis of the Strait, and basinwards from the margins. Silts and clays are deposited in deep water west and north of the delta front, and in deep basins northwest of the delta. Poorly sorted sediments containing a gravel component are located near tidal passes, on the Vancouver Island shelf area, on ridge tops within the Strait, and with sandy sediments at the southeastern end of the study area. The Pleistocene ridges are areas of non-deposition, having at most a thin veneer of modern mud on their crests and upper flanks. The southeastern end of the study area contains a thick wedge of shandy sediment which appears to be part of an earlier delta of the Fraser River. Evidence suggests that it is now a site of active submarine erosion. Sediments throughout the Strait are compositionally extremely similar, with-Pleistocene deposits of the Fraser River drainage basin providing the principal, heterogeneous source. Gravels and coarse sands are composed primarily of lithic fragments, dominantly of dioritic to granodloritlc composition. Sand fractions exhibit increasing simplicity of mineralogy with decreasing grain-size. Quartz, felspar, amphibole and fine-grained lithic fragments are the dominant constituents of the finer sand grades. Coarse and medium silt fractions have compositions similar to the fine sands. Fine silts show an increase in abundance of phyllosilicate material, a feature even more evident in the clay-size fractions on Montmorillonite, illite, chlorite, quartz and feldspar are the main minerals in the coarse clay fraction, with minor mixed-layer clays and kaolinite. The fine clay fraction is dominated by montmorillonite, with lesser amounts of illite and chlorite. The sediments have high base-exchange capacities, related to a considerable content of montmorillonite. Magnesium is present in exchange positions in greater quantity in Georgia Strait sediments than in sediments from the Fraser River, indicating a preferential uptake of this element in the marine environment. Manganese nodules collected from two localities in the Strait imply slow sediment accumulation rates at these sites. Sedimentation rates on and close to the delta, and in the deep basins to the northwest, are high.
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"Office of Water Regulations and Standards"--Cover.
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On August 6, 2010, a large (~50 Mm**3) debris avalanche occurred on the flank of Mount Meager in the southern Coast Mountains of British Columbia, Canada. We studied the deposits to infer the morphodynamics of the landslide from initiation to emplacement. Structure from motion (SfM) photogrammetry, based on oblique photos taken with a standard SLR camera during a low helicopter traverse, was used to create high-resolution orthophotos and base maps. Interpretation of the images and maps allowed us to recognize two main rheological phases in the debris avalanche. Just below the source area, in the valley of Capricorn Creek, the landslide separated into two phases, one water-rich and more mobile, and the other water-poor and less mobile. The water-rich phase spread quickly, achieved high superelevation on the valley sides, and left distal scattered deposits. The main water-poor phase moved more slowly, did not superelevate, and formed a thick continuous deposit (up to ~30 m) on the valley floor. The water-poor flow deposit has structural features such as hummocks, brittle-ductile faults, and shear zones. Our study, based on a freshly emplaced deposit, advances understanding of large mass movements by showing that a single landslide can develop multiple rheology phases with different behaviours. Rheological evolution and separation of phases should always be taken into account to provide better risk assessment scenarios.
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There are two features of /æ/ in British Columbia (BC) English that are widely attested in the literature: it is undergoing retraction and lowering and it is sensitive to the influence of certain following consonants. The present study aims to utilize both features to evaluate the phonological status of /æ/ before nasal consonants in BC English by examining the progression of sound change and the phonemic organization of /æ/ in different environments. Specifically, production and perception results are taken together to evaluate the phonetic position of pre-nasal /æ/ relative to other environments. These results are interpreted within a modular feedforward architecture of phonology to establish the phonological (allophonic) and phonetic (shallowphonic) rules that govern the internal relationships between the subphonemic elements of /æ/ in BC English. Further, the findings of this study provide evidence for the allophone being the target of sound change, rather than the phoneme.
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The Mount Meager Volcanic Complex (MMVC) in south-western British Columbia is a potentially active, hydrothermally altered massif comprising a series of steep, glaciated peaks. Climatic conditions and glacial retreat has led to the further weathering, exposure and de-buttressing of steep slopes composed of weak, unconsolidated material. This has resulted in an increased frequency of landslide events over the past few decades, many of which have dammed the rivers bordering the Complex. The breach of these debris dams presents a risk of flooding to the downstream communities. Preliminary mapping showed there are numerous sites around the Complex where future failure could occur. Some of these areas are currently undergoing progressive slope movement and display features to support this such as anti-scarps and tension cracks. The effect of water infiltration on stability was modelled using the Rocscience program Slide 6.0. The main site of focus was Mount Meager in the south- east of the Complex where the most recent landslide took place. Two profiles through Mount Meager were analysed along with one other location in the northern section of the MMVC, where instability had been detected. The lowest Factor of Safety (FOS) for each profile was displayed and an estimate of the volume which could be generated was deduced. A hazard map showing the inundation zones for various volumes of debris flows was created from simulations using LAHARZ. Results showed the massif is unstable, even before infiltration. Varying the amount of infiltration appears to have no significant impact on the FOS annually implying that small changes of any kind could also trigger failure. Further modelling could be done to assess the impact of infiltration over shorter time scales. The Slide models show the volume of material that could be delivered to the Lillooet River Valley to be of the order of 109 m3 which, based on the LAHARZ simulations, would completely inundate the valley and communities downstream. A major hazard of this is that the removal of such a large amount of material has the potential to trigger an explosive eruption of the geothermal system and renew volcanic activity. Although events of this size are infrequent, there is a significant risk to the communities downstream of the complex.
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The history of the settlement of the province is tied to patterns of exploration and min development. In Northern British Columbia the Cariboo goldfields provided the impetus for settlement of the region and the beginning for mining to extend into the watern and northern regions in a series of minor gold rushes. The northern half of the province has a geological diverse mineral base that supports a wide variety of mining, and a gradual improvement of exploration and mining methods due to scientific knowledge and technology provided opportunities for lode gold and base metal mines to be developed. The success of mining is based on world ore prices and competitive markets that impact the economic viability of developing a mine. Mining faces increasing pressures in the northern half of the province due to other resource values, such as tourism or protected areas, that claim and compete for a similar land base.
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Proceedings of the Fifth Annual Meeting Agenda Report of Opening Session Report of Governing Council Meetings Reports of Science Board and Committees Science Board Working Group 5: Bering Sea (Final Report) Working Group 9: Subarctic Pacific Monitoring Report of the First Meeting Report of the Second Meeting Biological Oceanography Committee Working Group 11: Consumption of Marine Resources by Marine Birds and Mammals Fishery Science Committee Working Group 12: Crabs and Shrimps Marine Environmental Quality Committee Working Group 8: Practical Assessment Methodology Physical Oceanography and Climate Committee Working Group 10: Circulation and Ventilation in the Japan Sea /East Sea and its Adjacent Areas Technological Committee on Data Exchange Finance and Administration Report of Finance and Administration Committee Assets on 31st of December, 1995 Income and Expenditures for 1995 Budget for 1997 Composition of the Organization Officers, Delegates, Finance and Administration Committee, Science Board, Secretariat, Scientific and Technical Committees List of Participants List of Acronyms (Document has 163 pages.)