West Coast Of Canada Research Articles

Physical oceanography of the western Canadian continental shelf

All regions of the Canadian west coast feel the influence of strong southeast storm winds in autumn and winter. Maximum wind speeds, currents and wave heights occur in late autumn and winter, with an abrupt transition in October/November marking the change from summer to winter regimes. In summer, surface circulation in all shelf regions is strongly influenced by buoyancy flux and by topographically controlled eddies, but in winter the flow is generally down wind. The cycle of southeast winds in winter and northwest winds in summer creates interesting annual signals. In Hecate Strait, bottom water in the central gully is warmest in winter, due to downwelling and mixing of surface waters by southeast winds. On the southern Vancouver Island shelf, lowest oxygen concentrations in bottom water are found in summer due to upwelling through Juan de Fuca Canyon and along the shelf break. Concentrations of nutrients in this upwelled water are high. Local tidal mixing does not appear to be sufficiently strong to bring these nutrients to the surface on the shelf, but instead, tidal currents in the Juan de Fuca-Strait of Georgia system and coastal upwelling on the shelf mix these nutrients to the surface, and local currents carry the nutrients to mid-shelf. Upwelling persists along the entire coast of Vancouver Island in summer, with a strong shelf break current flowing to the southeast, counter to the poleward, buoyancy-driven Vancouver Island Coastal Current over the inner shelf. All exposed coasts are subjected to extreme waves in winter, but Dixon Entrance and Hecate Strait are protected to some extent by the Queen Charlotte Islands. Nevertheless, the waves and currents in winter in northwestern Hecate Strait and southeastern Dixon Entrance move the sediments to the northeast, building up Rose Spit and eroding the northeastern shore of the Queen Charlotte Islands.

The Autocorrelation of Hourly Wind Speed Observations

Abstract The autocorrelation of hourly wind speed observations is estimated for seven stations on the west coast of Canada at selected lags ranging from one hour to two months. The estimated autocorrelation function is fitted by a model that includes a modified exponential term and cosine terms. The autocorrelation function declined more slowly than a simple exponential at six of the seven stations. For lags up to 12 hours autocorrelation coefficients were highest at those stations with the most uniform surrounding topography. The autocorrelation functions did not attenuate to zero at lags up to two months. An assumption of independent observations would underestimate standard errors of series statistics.

Time of maximum Late Wisconsin glaciation, West Coast of Canada

New data from a deep-sea core in the eastern North Pacific Ocean indicate that the western margin of the Late Wisconsin Cordilleran Ice Sheet began to retreat from its maximum position after 15,600 yr B.P. Ice-rafted detritus is present in the core below the 15,600 yr B.P. level and was deposited while lobes of the Cordilleran Ice Sheet advanced across the continental shelf in Queen Charlotte Sound, Hecate Strait, and Dixon Entrance. The core data are complemented by stratigraphic evidence and radiocarbon ages from Quaternary exposures bordering Hecate Strait and Dixon Entrance. These indicate that piedmont lobes reached the east and north shores of Graham Island (part of the Queen Charlotte Islands) between about 23,000 and 21,000 yr B.P. Sometime thereafter, but before 15,000–16,000 yr B.P., these glaciers achieved their greatest Late Wisconsin extent. Radiocarbon ages of late-glacial and postglacial sediments from Queen Charlotte Sound, Hecate Strait, and adjacent land areas show that deglaciation began in these areas before 15,000 yr B.P. and that the shelf was completely free of ice by 13,000 yr B.P.

Military radar defence lines of northern North America: an historical geography

AbstractNorthern Canada and Alaska from 1945 to 1951 had only a minor military presence and no radar surveillance of airborne threats. Fear of nuclear attack from the USSR led to the installation of numerous radar stations between 1951 and 1958. Alaska gained an inner and an outer arc of radar stations, and Canada the Pinetree Line, Mid-Canada Line, Distant Early Warning (DEW) Line and the little-known Pine-Gap radars of the east coast, from Newfoundland to Baffin Island. The Mid-Canada line closed in 1965 and the Pine-Gap stations were dismantled nine years later. The Pinetree and DEW lines ceased operation in 1988. Alaskan radar facilities were upgraded in the mid- 1980s, and in 1987 and 1988 similar radars were installed at the 14 stations of the North Warning Line, built along the abandoned DEW and Pine-Gap lines from northwestern Alaska to southern Labrador. Very long-range over-the-horizon radars at three locations will be completed by the early 1990s to monitor aircraft in the vicinity of Alaska and the east and west coasts of Canada. The ballistic missile early warning radars installed in the early 1960s in Alaska and Greenland received major improvements in the late 1980s.

Alaska Tsunami Warning Center's automatic and interactive computer processing system

The Alaska Tsunami Warning Center has the responsibility of providing timely tsunami warning services for Alaska and the west coasts of Canada and the United States. Recently, the ATWC implemented a new microcomputer system which is used for both automatic and interactive earthquake processing, and for disseminating critical information to the Tsunami Warning System recipients. Real-time seismic wave form data from 23 short-period and 9 long-period sites in Alaska, the lower 48 States, and Hawaii, are continually computer-monitored for the occurrence of an earthquake. Once detected from the short-period wave form data, pre- and post-earthquake data are displayed on a graphics terminal along with an indicator to identify the time of the onset of theP waves (P-picks). TheP-picks can easily be changed during or after data collection via a mouse. Magnitudes (M b ,M l ,M B ,M S ) are automatically computed from appropriate short- and long-period wave form data concurrently with the above processing. A second graphics terminal displays cycle-by-cycle long-period wave form data that was used to compute an earthquake'sM B andM S magnitudes. An earthquake's parametric data and other information are available and printed within tens of seconds after theP wave arrivals are recorded at the first 5 sites, then 7 sites, 9 sites, and a final parametric computation using all collected data. Three video display monitors are used for displaying the parameters, procedural aids, and a map showing the epicenter. Additionally, selected event parameters are immediately transmitted by VHF radio to alphanumeric beepers which are carried by standby duty personnel during those times that the Center is not manned. Using a dedicated video display terminal and printer, the interactive system can use data and parameters resulting from the automatic processes for concurrent parameter recomputations; perform additional computations; disseminate critical information; and generate procedural aids for duty geophysicists to facilitate an earthquake/tsunami investigation.

Rent dissipation in restricted access fisheries

Thirty-five years have passed since Gordon's seminal article on rent dissipation in open access fisheries. Restricted access fisheries, created to solve the problem, have not been successful. Three common sources of dissipated rent are input substitution, fleet redundancy, and fleet composition. Regulators on the west coast of Canada have focused on finding solutions for the first source. This paper questions the wisdom of past policy by developing and implementing a method for measuring rent dissipation in restricted access fisheries. Results from the British Columbia salmon fishery suggest that regulators should concentrate instead on improving fleet composition and removing excess vessels.

The Experience of Job Insecurity for Professional Women

In this article the authors examine the experience of job insecurity, as described by 20 women professionals living and working in a large metropolitan area on the west coast of Canada.

Variation among congeneric dinoflagellates from the northeastern United States and Canada

Relationships among dinoflagellates of the genus Alexandrium (=Protogonyaulax) from Long Island, New England, USA, and northeastern Canada were investigated between 1983 and 1987 using enzyme electrophoresis. A relative lack of heterogeneity among toxic isolates was observed despite large geographic separations of source populations. This observation is in marked contrast to observations on toxic members of this genus from the west coast of Canada and the United States. These different enzyme variability patterns support the proposal that dispersal of toxic strains in the east from a common source has occurred recently, presumably from established populations in northern Maine, USA, or Canada. Non-toxic strains from the study area were only distantly related to toxic isolates, consistent with their different morphology and separate species designations. One non-toxic isolate from a different region, that is conspecific with a number of the toxic strains, was more similar to these isolates than to other non-toxic clones.

Coastal studies with the thematic mapper on the west coast of Canada

Examples are shown of TM coverage of a coastal inlet for which maps of near surface colour and thermal structure were required to study their potential impact on fish migration. The results are compared to airborne thermal and visible imagery of the same area, and to surface measurements. For water studies, the TM appears primarily useful for its 120 m resolution thermal coverage.

The Importance of Shifts in Language Level and Extraneous Information in Determining Word Problem Difficulty

A sample of 84 Grade 6 students from a Canadian west coast city were administered a set of 80 arithmetic word problems. The problems were developed as part of a larger set intended to reflect individual differences in problem solving. These particular problems were varied in the grade level of language and in the type and amount of extraneous information present. The items appear to be both reliable (internal consistency of the items, Cronbach alpha, for sets of 16 items ranged from 0.86 to 0.88) and valid (criterion-related and concurrent validity were indicated by consistently significant correlations with reading and mathematics achievement measures). Significant overall effects were observed when three CTBS mathematics achievement groups were compared on problems varying vocabulary level and extraneous information.

The Canadian West Coast Punk Subculture: A Field Study

This field study of the punk rock subculture is an exploratory examination in the much neglected area of Canadian adolescent subcultures. The data consist of transcribed unstructured interviews with subculture members and field notes gathered during the observation period. Functionalist and neo-Marxist theories of subculture were used as guides to inquiry. The results reveal that the punk subculture is a classless form of delinquent youth culture. Members were seen to be reacting to the age and generational effect of youth employment opportunities. They displayed varying levels of resistance to dominant cultural goals, school, and the family. Severity of the resistance was related to gender. Political attitudes were characterized by a libertarian conscious- ness that served to mute political resistance. While members could not address issues of unemploy- ment, poverty, and alienating labour, they were able to achieve status through participation in the subculture and violence.

Application of Seasat Scatterometer Wind Measurements for Operational Short-Range Weather Forecasting

The availability of the Seasat Scatterometer provided the first opportunity to study the impact of adding satellite-derived surface wind data to short-range regional analyses and forecasts. Six cases on the west coast of Canada and the United States were used for this study. Surface analyses done operationally by the Pacific Weather Centre using conventional data were reanalyzed using Seasat Scatterometer wind data. In all of the six cases there were significant improvements in the surface analyses. Wind forecasts demonstrated significant improvement only when the scatterometer observations were in the forecast areas. Important meteorological features, including high and low pressure centers, ridges, troughs, shear zones and cols, were more clearly and accurately defined.

Immunoglobulin (GM and KM) allotypes and relation to population history in native peoples of British Columbia: Haida and Bella Coola.

Differences in the frequencies of GM haplotypes among native peoples of the Americas support the hypothesis that there were three distinct waves of migration from northeast Asia into the Americas: Paleo-Indian, Na-Dene, and Inuit (Eskimo)-Aleut (Salzano and Steinberg: Am. J. Hum. Genet. 17:273-279, 1965; Sukernik and Osipova: Hum. Genet. 61:148-153, 1982; Williams et al.:Am. J. Phys. Anthropol. 66:1-19, 1985; Szathmary: In R Kirk and E Szathmary (eds): Out of Asia: Peopling of the Americas and the Pacific. Canberra: The Journal of Pacific History, Canberra Australian National University, pp. 79-104, 1985). We studied GM allotypes in two linguistically unique populations of Canadian west coast native peoples, the Haida and the Bella Coola, and compared them to GM frequencies in populations that are supposed descendants of the three migrations, in order to investigate the possible genetic relationships of these British Columbia (BC) groups to other native populations. We also estimated the amount of European admixture from the frequency of the Caucasian haplotype, Gm3;5. Results showed that the frequencies in both BC populations of the three common native haplotypes (Gm1,17;21, Gm1,2,17;21, and Gm1,17;15,16), were intermediate between the frequencies in supposed descendants of Paleo-Indian and Na-Dene. These genetic findings are consistent with the controversial hypothesis of archeologist C. Borden (Science 203:963-971, 1979) that, following deglaciation about 13,000 years ago, British Columbia was repopulated by peoples from the north (?Na-Dene) and by culturally distinct peoples from the south (?Paleo-Indian). Caucasian admixture estimates suggested that the Haida and Bella Coola have also experienced moderate amounts (12-20%) of genetic input from European-originating peoples.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of mercury presence and exposure in a lighthouse with a mercury drive system

It is common practice for lighthouses with large Fresnel lenses to use mercury baths as a low-friction rotation mechanism. Some recent acute mercury poisonings and incidents of abnormal behavior in lighthouse keepers have drawn attention to the potential for chronic mercury poisoning in these workplaces. This study evaluated the distribution of mercury in a lighthouse on the Canadian west coast, and the exposure of its keepers and their spouses under two weather conditions. The urine mercury levels found in the lighthouse personnel were all less than would be expected in an occupationally exposed group (less than 4 micrograms/24 hr urine). Air concentrations in the lighthouse ranged from 4.4 to 26.3 micrograms/m3. Swabbing showed considerable accumulation of mercury on surfaces in the area of the light rotation mechanism, as well as transport throughout the lighthouse. The mercury levels in this lighthouse appeared to be under control through effective convective ventilation and employee awareness. The study signals potential problems where precautions have not been taken, especially in situations where the keepers and their families live in the lighthouse.

Estimation of the elastic properties of seafloor sediments by inversion of precritical reflection data

A method has been presented for estimating the elastic properties of sea-floor sediment by inverting the amplitude-range information of precritical reflection data. The method was tested using synthetic data for reflection from a half-space sediment model and the estimates values for the P- and S-wave speeds and the density were in good agreement with the geoacoustic model parameters. The synthetic data were also used to determine the sensitivity of the method to interference from reflections from subbottom layers. In most practical cases the interference is not likely to be a problem for precritical reflection data. The method was then applied to measurements of seafloor reflection obtained in an experiment carried out off the west coast of Canada. The estimated values of the elastic properties of the topmost sediment layer were consistent with values available from the literature, and with estimates from other experiments carried out in the same region.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Resident and Dispersal Behavior of Adult Sablefish (Anaplopoma fimbria) in the Slope Waters off Canada's West Coast

A total of 72 735 adult sablefish (Anaplopoma fimbria) were tagged and released off the west coast of Canada from 1977 to 1982. As of December 31, 1985, 11 212 (15%) have been recaptured or 16 539 (23%) when recaptures were standardized for differences in recovery effort and unreported recaptures. Off Vancouver Island, relatively few sablefish moved more than 200 km. More movement occurred in Queen Charlotte Sound and off the Queen Charlotte Islands. Thirteen percent of recaptures were made in the United States zone and 96% of these were made in waters off Alaska. Movement was not related to length, age, or sex of adult fish. There was also no relationship between time at liberty and distance travelled; however, there was a trend to move out of the release area with time at liberty. In general, most adults remained within the release area. This resident behavior could result in overfishing because recruitment is dependent on occasional strong year-classes rather than movement from other areas.

Establishment of crustal deformation networks using gps: a case study

This paper describes the analysis of Global Positioning System (GPS) observations for the determination of precise relative coordinates in two networks established to monitor crustal deformation on the west coast of Canada. Following the description of the networks and their observation schedules, the computer software used for the data reduction is reviewed and typical GPS relative positioning errors are discussed. To assess the internal consistency of GPS positioning, single baseline results are compared to those obtained in an overall network adjustment for both networks. It is found that the consistency in horizontal coordinates is better than that in the vertical coordinate by a factor of about 3. For one of the networks, which is mostly in a mountainous area, the consistency of the vertical coordinates is improved slightly when standard instead of observed meteorological data is used. The comparison of baseline lengths obtained from the GPS network adjustment and from the adjustment of terrestrial EDM measurements reveals a relative scale factor of 1.2 parts per million with residual discrepancies of 8 mm (rms). This precision will allow the determination of accumulating strain with these GPS monitoring networks within a period of five years.

Annual Cycle of Bacterial Specific Biovolumes in Howe Sound, a Canadian West Coast Fjord Sound

The mean specific biovolumes (biovolume cell) of the bacterioplankton within a 250-m-deep water column in Howe Sound, British Columbia, were determined for the period of 4 September 1984 to 23 October 1985. These bacteria had an annual cycle in mean specific biovolume; they were small (ca. 0.058 mum) in mid-winter, larger in spring (ca. 0.076 mum), larger again in summer (up to 0.102 mum), and largest (ca. 0.133 mum) in early fall (immediately after the decrease in phytoplankton production). The mean specific biovolumes changed coincidently through the water column with time, although the larger bacterioplankton tended to occur in the surface and deepest water. Although the mean specific biovolumes correlated better with in situ temperature (r = 0.65, a = 0.01) than with in situ chlorophyll a concentration (r = 0.34, a = 0.25), modeling experiments with batch cultures of the dinoflagellate Prorocentrum minimum (Pavillard) and the green alga Dunaliella tertiolecta (Butcher) indicated that the biomass and physiological condition of the phytoplankters may be more important than temperature in determining these bacterial specific biovolumes.

Measurement and modeling of downslope acoustic propagation loss over a continental slope

Measurements of propagation loss were obtained in an experiment to study downslope acoustic propagation over the continental slope off the Canadian west coast. The propagation was strongly influenced by the bathymetry and a downslope enhancement was observed at a receiver in the deep sound channel for shallow explosive charges deployed over the continental slope. The maximum enhancement was observed for sources near the edge of the continental shelf at a range of about 110 km, where conversion to low-loss water column propagation paths by bottom interaction occurred at a depth approximately equal to the sound channel axis. The propagation loss measured for these sources was as much as 15 dB less than that estimated for propagation over a flat ocean bottom, and was equivalent to levels recorded for sources at only 25–30 km. The data were interpreted by examining the structure of the signals received from the charges deployed over the slope, and by using ray theory to determine the propagation paths. The range dependence of the propagation loss was modeled using a wide-angle parabolic equation method with a realistic geoacoustic model of the environment which included sound speed, density, and attenuation profiles. The model results were in excellent agreement with the measured values over the entire frequency band of the measurements.

A tidal model of the northeast Pacific [west coast of Canada

A tidal model of the northeast Pacific [west coast of Canada