scholarly journals Analysis of CCSS data set I: reflection-refraction data from the Vancouver Island continental margin of western Canada

1990 ◽  
Author(s):  
C M R Fowler ◽  
B I Pandit
Keyword(s):  
Continental Margin ◽  
Vancouver Island ◽  
Western Canada ◽  
Data Set ◽  
Refraction Data

Comparison of the S/N ratios of low-frequency hydrophones and geophones as a function of ocean depth

1981 ◽  
Vol 71 (5) ◽  
pp. 1649-1659
Author(s):  
Thomas M. Brocher ◽  
Brian T. Iwatake ◽  
Joseph F. Gettrust ◽  
George H. Sutton ◽  
L. Neil Frazer
Keyword(s):  
Nova Scotia ◽  
Continental Margin ◽  
Low Frequency ◽  
Weather Conditions ◽  
Ocean Bottom ◽  
Ocean Bottom Seismometer ◽  
Scotian Shelf ◽  
Ocean Bottom Seismometers ◽  
Particle Velocities ◽  
Refraction Data

abstract The pressures and particle velocities of sediment-borne signals were recorded over a 9-day period by an array of telemetered ocean-bottom seismometers positioned on the continental margin off Nova Scotia. The telemetered ocean-bottom seismometer packages, which appear to have been very well coupled to the sediments, contained three orthogonal geophones and a hydrophone. The bandwidth of all sensors was 1 to 30 Hz. Analysis of the refraction data shows that the vertical geophones have the best S/N ratio for the sediment-borne signals at all recording depths (67, 140, and 1301 m) and nearly all ranges. The S/N ratio increases with increasing sensor depth for equivalent weather conditions. Stoneley and Love waves detected on the Scotian shelf (67-m depth) are efficient modes for the propagation of noise.

Integrated geophysical modelling of terranes and other structural features along the western Canadian margin

1992 ◽  
Vol 29 (7) ◽  
pp. 1492-1508 ◽  
Author(s):  
S. A. Dehler ◽  
R. M. Clowes
Keyword(s):  
Seismic Refraction ◽  
Vancouver Island ◽  
Structural Features ◽  
Pacific Rim ◽  
Data Set ◽  
Reflection Seismic ◽  
Barkley Sound ◽  
The Pacific ◽  
Wrangellia Terrane ◽  
Lower Crustal

An integrated geophysical data set has been used to develop structural models across the continental margin west of Vancouver Island, Canada. A modern accretionary complex underlies the continental slope and shelf and rests against and below the allochthonous Crescent and Pacific Rim terranes. These terranes in turn abut against the pre-Tertiary Wrangellia terrane that constitutes most of the island. Gravity and magnetic anomaly data, constrained by seismic reflection, seismic refraction, and other data, were interpreted to determine the offshore positions of these terranes and related features. Iterative 2.5-dimensional forward models of anomaly profiles were stepped laterally along the margin to extend areal coverage over a 70 km wide swath oriented normal to the tectonic features. An average model was then developed to represent this part of the margin. The Pacific Rim terrane appears to be continuous and close to the coastline along the length of Vancouver Island, consistent with emplacement by strike-slip motion along the margin. The Westcoast fault, the boundary between the Pacific Rim and Wrangellia terranes, is interpreted to be 15 km farther seaward than in previous interpretations in the region of Barkley Sound. The Crescent terrane forms a thin landward-dipping slab along the southern half of the Vancouver Island margin, and cannot be confirmed along the northern part. Model results suggest the slab has buckled into an anticline beneath southern Vancouver Island and Juan de Fuca Strait, uplifting high-density lower crustal or upper mantle material close to the surface to produce the observed intense positive gravity anomaly. This geometry is consistent with emplacement of the Crescent terrane by oblique subduction.

Bathymetric map of the continental margin of western Canada

1975 ◽  
Author(s):  
D A Seemann ◽  
D L Tiffin
Keyword(s):  
Continental Margin ◽  
Western Canada ◽  
Bathymetric Map

Evaluation of on-farm crop management decisions on canola productivity

2014 ◽  
Vol 94 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Chang Liu ◽  
Yantai Gan ◽  
Lee Poppy
Keyword(s):  
Seed Yield ◽  
Combine Method ◽  
Crop Management ◽  
Western Canada ◽  
Key Factors ◽  
Management Decisions ◽  
Data Set ◽  
K Fertilizer ◽  
Farm Crop ◽  
On Farm

Liu, C., Gan, Y. and Poppy, L. 2014. Evaluation of on-farm crop management decisions on canola productivity. Can. J. Plant Sci. 94: 131–139. This study determined key factors affecting canola productivity in western Canada and evaluated the differences among soil-climatic zones in canola crops responding to the key agronomic factors. A total of 68 canola farm fields were randomly selected in western Canada, and multiple correspondence analysis, coupled with multivariate predictive model with partial least squares projection and regressions, was used to analyze the data set. Canola produced in Alberta averaged 2500 kg ha−1, and was 23% greater than canola produced in southern Saskatchewan, 10% greater than canola produced in northern Saskatchewan, and 59% greater than canola produced in Manitoba. Canola produced on chem-fallow averaged 2557 kg ha−1, and was 17% greater than canola grown on cereal stubble, or 43% greater than canola grown on pea/lentil, corn stubble. Canola grown on canola stubble produced 54% of the seed yield as canola grown on cereal stubble, or 46% of the seed yield as canola grown on chem-fallow. Shallow and earlier seeding with narrow row spacing increased canola seed yields consistently. Canola receiving K fertilizer increased seed yield by an average of 25% compared with those receiving no K fertilizer. Straight combine resulted in 500 kg ha−1 or 24% more seed yield than conventional swath-combine method. Those key factors may serve as the first-hand information in the development of sound guidelines for less experienced canola producers in western Canada.

Notes on Polychaeta from the East Coast of Vancouver Island and from Adjacent Waters, with a Description of a New Species of Aricidea

1956 ◽  
Vol 13 (4) ◽  
pp. 541-546 ◽  
Author(s):  
E. Berkeley ◽  
C. Berkeley
Keyword(s):  
New Species ◽  
North America ◽  
East Coast ◽  
Vancouver Island ◽  
Western Canada ◽  
Western North America ◽  
A New Species

Records are given of two species and a variety new to western Canada and notes on three other species already known from the region. A new species, Aricidea lopezi, and four species new to western North America, are described from the neighbourhood of Friday Harbour, Washington.

scholarly journals Depressive symptoms in long term care facilities in Western Canada: a cross sectional study

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Matthias Hoben ◽  
Abigail Heninger ◽  
Jayna Holroyd-Leduc ◽  
Jennifer Knopp-Sihota ◽  
Carole Estabrooks ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Depressive Symptoms ◽  
Long Term Care ◽  
Assessment Instrument ◽  
Western Canada ◽  
Cross Sectional ◽  
Term Care ◽  
Data Set ◽  
For Profit

Abstract Background The main objective is to better understand the prevalence of depressive symptoms, in long-term care (LTC) residents with or without cognitive impairment across Western Canada. Secondary objectives are to examine comorbidities and other factors associated with of depressive symptoms, and treatments used in LTC. Methods 11,445 residents across a random sample of 91 LTC facilities, from 09/2014 to 05/2015, were stratified by owner-operator model (private for-profit, public or voluntary not-for-profit), size (small: < 80 beds, medium: 80–120 beds, large > 120 beds), location (Calgary and Edmonton Health Zones, Alberta; Fraser and Interior Health Regions, British Columbia; Winnipeg Health Region, Manitoba). Random intercept generalized linear mixed models with depressive symptoms as the dependent variable, cognitive impairment as primary independent variable, and resident, care unit and facility characteristics as covariates were used. Resident variables came from the Resident Assessment Instrument – Minimum Data Set (RAI-MDS) 2.0 records (the RAI-MDS version routinely collected in Western Canadian LTC). Care unit and facility variables came from surveys completed with care unit or facility managers. Results Depressive symptoms affects 27.1% of all LTC residents and 23.3% of LTC resident have both, depressive symptoms and cognitive impairment. Hypertension, urinary and fecal incontinence were the most common comorbidities. Cognitive impairment increases the risk for depressive symptoms (adjusted odds ratio 1.65 [95% confidence interval 1.43; 1.90]). Pain, anxiety and pulmonary disorders were also significantly associated with depressive symptoms. Pharmacologic therapies were commonly used in those with depressive symptoms, however there was minimal use of non-pharmacologic management. Conclusions Depressive symptoms are common in LTC residents –particularly in those with cognitive impairment. Depressive symptoms are an important target for clinical intervention and further research to reduce the burden of these illnesses.

scholarly journals Effects of Cenozoic subduction along the outboard margin of the Northern Cordillera: Derived from e-book on the Northern Cordillera (Alaska and Western Canada) and adjacent marine areas

Geosphere ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 33-61
Author(s):  
Warren J. Nokleberg ◽  
David W. Scholl ◽  
Thomas K. Bundtzen ◽  
David B. Stone
Keyword(s):  
Continental Margin ◽  
Subduction Zones ◽  
Hot Springs ◽  
Sedimentary Basins ◽  
Oceanic Lithosphere ◽  
Popular Science ◽  
Strike Slip ◽  
Western Canada ◽  
Regional Effects ◽  
Marine Areas

Abstract This article describes the regional effects of Cenozoic subduction along the outboard margin of the Northern Cordillera (Alaska, USA, and Western Canada), and thereby acquaints the reader with several chapters of the e-book Dynamic Geology of the Northern Cordillera (Alaska, Western Canada, and Adjacent Marine Areas). This article and the e-book are written for earth-science students and teachers. The level of writing for the article and the source e-book is that of popular science magazines, and readers are encouraged to share this article with students and laypersons. The main thrust of the article is to present and describe a suite of ten regional topographic, bathymetric, and geologic maps, and two figures portraying deep-crustal sections that illustrate the regional effects of Cenozoic subduction along the outboard margin of the North American Cordillera. The regional maps and cross sections are described in a way that a teacher might describe a map to students. Cenozoic subduction along the margin of the Northern Cordillera resulted in the formation of the following: (1) underthrusting of terranes and oceanic lithosphere beneath Southern Alaska; (2) landscapes, including narrow continental shelves along Southern and Southeastern Alaska and Western Canada (the Canadian Cordillera) and continental-margin mountain ranges, including the Alaska Peninsula, Chugach Range, Saint Elias Mountains, and Cascade Mountains; (3) sedimentary basins; (4) an array of active continental strike-slip and thrust faults (inboard of subduction zones); (5) earthquake belts related to subduction of terranes and oceanic plates; (6) active volcanoes, including continental-margin arcs (the Aleutian, Wrangell, and Cascade Arcs) linked to subduction zones, and interior volcanic belts related to strike-slip faulting or to hot spots; (7) lode and placer mineral deposits related to continental margin arcs or subduction of oceanic ridges; (8) hot springs related to continental-margin arcs; (9) plate movements as recorded from GPS measurements; and (10) underthrusting of terranes and oceanic lithosphere beneath the Northern Cordillera.

scholarly journals Seasonal current simulations for the western continental margin of Vancouver Island

2000 ◽  
Vol 105 (C8) ◽  
pp. 19665-19698 ◽  
Author(s):  
M. G. G. Foreman ◽  
R. E. Thomson ◽  
C. L. Smith
Keyword(s):  
Continental Margin ◽  
Vancouver Island
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