A new analysis of geomagnetic depth-sounding data from western Canada

1970 ◽  
Vol 7 (5) ◽  
pp. 1208-1218 ◽  
Author(s):  
N. A. Cochrane ◽  
R. D. Hyndman
Keyword(s):  
British Columbia ◽  
Transfer Function ◽  
Transition Zone ◽  
Spatial Dependence ◽  
Western Canada ◽  
Time Varying ◽  
Mantle Transition Zone ◽  
Geomagnetic Fields ◽  
Depth Sounding ◽  
East West

Time varying geomagnetic fields observed in southern British Columbia and Alberta are analyzed using optimum "transfer function" techniques for periods from 4 to 240 min. Estimates of the frequency and spatial dependence of the "coast effect" are obtained. Inland anomalies are delineated and attributed to variations in conductivity in the upper-to-middle crust coupled with an abrupt east–west transition in deeper conductivity. Regional attenuation of the uncorrelated portion of the vertical magnetic component is indicative of high conductivity near the crust mantle transition zone under the western part of the Cordillera. The conclusion is in agreement with magnetotelluric observations and other geophysical data.

A large-scale magnetotelluric survey in Western Canada

1969 ◽  
Vol 6 (5) ◽  
pp. 1245-1261 ◽  
Author(s):  
B. Caner ◽  
P. A. Camfield ◽  
F. Andersen ◽  
E. R. Niblett
Keyword(s):  
British Columbia ◽  
Upper Mantle ◽  
Large Scale ◽  
Conducting Layer ◽  
Western Canada ◽  
Period Range ◽  
A Value ◽  
Depth Sounding ◽  
Lower Crustal ◽  
Conducting Zone

Five magnetotelluric stations were operated in two clusters in southern British Columbia and Alberta, in order to determine the conductivity structures in each of the two main regions delineated by geomagnetic depth-sounding. A wide period range was covered (20 to 7500 seconds), to permit resolution of structure at lower crustal and upper mantle depths.At the eastern cluster (Pincher, Fernie), a moderately conducting zone (30–50 ohm-meters) is defined starting at depth 30–35 km and extending to a depth of at least 100 km. At the western cluster (Penticton, Osoyoos, Grand Forks) a conducting layer (10 ± 5 ohm-meters) starts at depth 15 ± 5 km; below this layer (of thickness 20–40 km) the resistivity increases to a value of the same order (30–50 ohm-meters) as at the eastern cluster.

Theoretical modeling of the regular olivine intergrowths in the mimetic paramorphosis after ringwoodite and wadsleyite

2018 ◽  
pp. 3-12
Author(s):  
B. B. Shkursky
Keyword(s):  
Transition Zone ◽  
Theoretical Modeling ◽  
Mantle Transition Zone ◽  
Misorientation Angles

Theoretical modeling of regular olivine grains misorientations in mimetic paramorphoses after ringwoodite and wadsleyite, the formation of which during the ascension of matter from the Mantle Transition Zone is expected, has been carried out. The coordinates of the misorientation axes and the misorientation angles, characterizing 10 operations of alignment in the pair intergrowths of olivine grains, eight of which are twins, are calculated. Possible conditions for the formation of mimetic paramorphoses predicted here, and the chances of their persistence are discussed. The calculated orientations are compared with the known twinning laws of olivine.

scholarly journals A thin mantle transition zone beneath the equatorial Mid-Atlantic Ridge

Nature ◽  
2021 ◽  
Vol 589 (7843) ◽  
pp. 562-566
Author(s):  
Matthew R. Agius ◽  
Catherine A. Rychert ◽  
Nicholas Harmon ◽  
Saikiran Tharimena ◽  
J.-Michael Kendall
Keyword(s):  
Transition Zone ◽  
Mantle Transition Zone ◽  
Mid Atlantic Ridge

Residential winter kWh responsiveness under optional time-varying pricing in British Columbia

2013 ◽  
Vol 108 ◽  
pp. 288-297 ◽  
Author(s):  
C.K. Woo ◽  
R. Li ◽  
A. Shiu ◽  
I. Horowitz
Keyword(s):  
British Columbia ◽  
Time Varying

scholarly journals Challenging the Stereotypes: Unexpected Features of Sexual Exploitation among Homeless and Street-Involved Boys in Western Canada

2021 ◽  
Vol 18 (11) ◽  
pp. 5898
Author(s):  
Elizabeth M. Saewyc ◽  
Sneha Shankar ◽  
Lindsay A. Pearce ◽  
Annie Smith
Keyword(s):  
British Columbia ◽  
Sexual Exploitation ◽  
Western Canada ◽  
Youth Health

Research about the sexual exploitation of homeless and street-involved boys is limited and often combined with that of girls. As aggregation can distort unique issues among genders which are exploited, this study provides information about the context of exploitation for homeless boys. Boys participated in the anonymous, multi-city British Columbia (BC), Canada Homeless and Street-Involved Youth Health paper surveys of 2006 and 2014. Measures included questions about trading sex for money, shelter, or other consideration; age first exploited; for whom; where they were living when first traded sex; gender of exploiters; and demographics. Analyses, separately for younger/older boys, explored the prevalence, timing of exploitation vs. homelessness, and ANOVAs to evaluate the patterns of the age of first exploitation by the genders of exploiters. Just over one in four boys reported exploitation (n = 132), with a median age of 14–15 in most groups. Most were runaway or homeless before their first exploitation, but 25.5% (2006) and 41% (2014) were living with family. Most boys were exploited by women (78%–85%), with 62%–65% were exclusively exploited by women.

Impact of cultivars and herbicides on weed management in alfalfa

2006 ◽  
Vol 86 (3) ◽  
pp. 875-885 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya
Keyword(s):  
British Columbia ◽  
Weed Control ◽  
Weed Management ◽  
Forage Quality ◽  
Western Canada ◽  
Downy Brome ◽  
Weed Species ◽  
Standard Type ◽  
Southern Alberta ◽  
Medicago Sativa L

Weeds, especially dandelion (Taraxacum officinale Weber in F.H. Wigg.), tend to infest a forage alfalfa (Medicago sativa L.) stand 2 to 4 yr after establishment. To develop better weed management systems, experiments were conducted at Lethbridge, Alberta, from 1995 to 2002 and Creston, British Columbia, from 1998 to 2001, which included the alfalfa cultivars Beaver (standard type) and AC Blue J (Flemish type) and annual applications of metribuzin and hexazinone. These herbicides are registered for weed control in irrigated alfalfa in Alberta and alfalfa grown for seed. In addition, two sulfonylurea herbicides, metsulfuron and sulfosulfuron, and glyphosate were included. All of the herbicides except glyphosate controlled or suppressed dandelion and mustard family weeds. Metsulfuron at 5 g a.i. ha-1 almost completely controlled dandelion at both locations. However, after metsulfuron application at Lethbridge, dandelion was replaced with an infestation of downy brome, which is unpalatable for cattle. None of the herbicides increased total forage (alfalfa + weed) yield, and in some instances herbicides reduced forage quality by causing a shift from a palatable to an unpalatable weed species. However, it was observed that AC Blue J consistently yielded more than Beaver, and weed biomass was consistently less in the higher-yielding cultivar. AC Blue J was developed primarily for the irrigated area in southern Alberta and for southern British Columbia. Therefore, additional experiments should be conducted to determine which alfalfa cultivars have the greatest ability to compete with weeds in other regions of western Canada. Key words: Alfalfa yield, dandelion, forage quality, weed control

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