The Cowichan Ice tongue, Vancouver Island

1968 ◽  
Vol 5 (6) ◽  
pp. 1409-1415 ◽  
Author(s):  
E. Carl Halstead
Keyword(s):  
British Columbia ◽  
Late Glacial ◽  
Vancouver Island ◽  
Glacial Deposits ◽  
Strait Of Georgia ◽  
Continuous Melting

The sequence of late glacial deposits within Cowichan Valley and on Saanich Peninsula, Vancouver Island, British Columbia, suggests the existence of an ice tongue that occupied Cowichan Valley and extended eastward to Saanich Peninsula prior to the merging with and being overridden by Cordilleran ice of the last major glaciation. Following the maximum advance of Cordilleran ice, continuous melting and downwasting prevailed, but before deglaciation was complete, remnant ice in Cowichan Valley was rejuvenated. Similar glacio-climatic events have been recognized elsewhere in the Strait of Georgia, and are named the Evans Creek Stade, the Vashon Stade, and the Sumas Stade of the Fraser glaciation. The writer tentatively applies these names to the events on Vancouver Island.

PALAEOBOTANICAL STUDY OF LATE-GLACIAL DEPOSITS FROM VANCOUVER ISLAND, BRITISH COLUMBIA

1959 ◽  
Vol 37 (5) ◽  
pp. 815-817 ◽  
Author(s):  
J. Terasmae ◽  
J. G. Fyles
Keyword(s):  
British Columbia ◽  
Radiocarbon Dating ◽  
Late Glacial ◽  
Vancouver Island ◽  
River Section ◽  
Glacial Deposits ◽  
Palynological Study

Plant-bearing beds have been discovered by J. G. Fyles in late-glacial deposits from the Englishman River section, Vancouver Island, B.C. Radiocarbon dating indicated an age of ca. 12,000 years for these beds. Fossil cones of Pinus contoria Dougl. and leaves of Dryas drummondii Richards, were discovered and identified. Palynological study indicates that climate at the time was colder than the present.

Review: Receiver function studies in the southern Canadian Cordillera

1995 ◽  
Vol 32 (10) ◽  
pp. 1514-1519 ◽  
Author(s):  
John F. Cassidy
Keyword(s):  
British Columbia ◽  
Upper Mantle ◽  
Receiver Function ◽  
Vancouver Island ◽  
Moho Depth ◽  
Canadian Cordillera ◽  
Low Velocity ◽  
Strait Of Georgia ◽  
Low Velocity Zone ◽  
Velocity Zone

Receiver function analysis has proven to be a powerful, yet inexpensive tool for estimating the S-wave velocity structure of the crust and upper mantle beneath three-component seismograph stations in the southern Canadian Cordillera. Receiver function studies using a portable broadband seismograph array across southwestern British Columbia provided site-specific estimates for the location of the subducting Juan de Fuca plate. The oceanic crust was imaged at 47−53 km beneath central Vancouver Island, and 60–65 km beneath the Strait of Georgia. Further, these studies revealed a prominent low-velocity zone (VS = −1.0 km/s) that coincides with the E reflectors imaged ~5–10 km above the subducting plate on Lithoprobe reflection lines. The E low-velocity zone was shown to extend into the upper mantle beneath the Strait of Georgia and the British Columbia mainland, to depths of 50–60 km. Combining the receiver function and refraction models revealed a high Poisson's ratio (0.27–0.38) for this feature. The continental Moho was estimated at 36 km beneath the Strait of Georgia, and a crustal low-velocity zone associated with the Lithoprobe C reflectors beneath Vancouver Island was interpreted to extend eastward, near the base of the continental crust, to the British Columbia mainland. Analysis of data from the recently deployed Canadian National Seismograph Network demonstrates the variations in crustal thickness and complexity across the southern Canadian Cordillera, with the Moho depth varying from 35 km in the Coast Mountains, to 33 km near Penticton, to 50 km near the Rocky Mountain deformation front.

A Statistical Examination of Anisakis Larvae (Nematoda) in Herring (Clupea pallasi) of the British Columbia Coast

1955 ◽  
Vol 12 (4) ◽  
pp. 571-592 ◽  
Author(s):  
Yvonne M. M. Bishop ◽  
Leo Margolis
Keyword(s):  
British Columbia ◽  
West Coast ◽  
Maximum Level ◽  
Vancouver Island ◽  
First Year ◽  
Intensity Of Infection ◽  
The West ◽  
Strait Of Georgia ◽  
Clupea Pallasi ◽  
First Year Of Life

The presence of larval Anisakis in British Columbia herring was examined during the winter fisheries of 1950–51 and 1951–52. In the commercial catches in the Strait of Georgia the incidence was found to be between 80 and 90%. In Hecate Strait, on the west coast of Vancouver Island and in the mainland coastal area of Queen Charlotte Sound it was between 90 and 100%. The intensity of infection varied greatly in different fishing areas (i.e. in different herring populations). Generally, the maximum level of infection occurred in the Queen Charlotte Sound coastal regions, and decreased both north and south of this area. Fish on the west coast of Vancouver Island were more heavily infected than those on the east coast (Strait of Georgia). The level of infection increased with age, I-year fish (i.e. fish in their first year of life) being uninfected. The intensity of infection remained constant throughout the winter for any particular age and area and was the same for both sexes. In most areas the level of infection was a little lower in 1951–52 than in 1950–51.

Late Pleistocene history and geomorphology, southwestern Vancouver Island, British Columbia

1979 ◽  
Vol 16 (9) ◽  
pp. 1645-1657 ◽  
Author(s):  
Neville F. Alley ◽  
Steven C. Chatwin
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
Late Pleistocene ◽  
Vancouver Island ◽  
Glacial Lakes ◽  
Small Lakes ◽  
Strait Of Georgia ◽  
Coast Mountains ◽  
Juan De Fuca ◽  
Juan De Fuca Strait

The major Pleistocene deposits and landforms on southwestern Vancouver Island are the result of the Late Wisconsin (Fraser) Glaciation. Cordilleran glaciers formed in the Vancouver Island Mountains and in the Coast Mountains had advanced down Strait of Georgia to southeastern Vancouver Island after 19 000 years BP. The ice split into the Puget and Juan de Fuca lobes, the latter damming small lakes along the southwestern coastal slope of the island. During the maximum of the glaciation (Vashon Stade), southern Vancouver Island lay completely under the cover of an ice-sheet which flowed in a south-southwesterly direction across Juan de Fuca Strait, eventually terminating on the edge of the continental shelf. Deglaciation was by downwasting during which ice thinned into major valleys and the strait. Most upland areas were free of ice down to an elevation of 400 m by before 13 000 years BP. A possible glacier standstill and (or) resurgence occurred along Juan de Fuca Strait and in some interior upland valleys before deglaciation was complete. Glacial lakes occupied major valleys during later stages of deglaciation.

Anomalous Occurrence of Carp (Cyprinus carpio) in the Marine Environment

1971 ◽  
Vol 28 (9) ◽  
pp. 1345-1347 ◽  
Author(s):  
W. E. Barraclough ◽  
D. G. Robinson
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Surface Waters ◽  
Cyprinus Carpio ◽  
River Estuary ◽  
Vancouver Island ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Low Salinity ◽  
Carp Cyprinus Carpio

Juvenile carp (Cyprinus carpio) were caught with a surface trawl in low salinity surface waters of the Strait of Georgia, British Columbia, during July 1967. A natural environmental route is established for the possible movement of carp from the Fraser River estuary to watersheds on Vancouver Island.

Recent Trends in the Abundance of Harbour Seals, Phoca vitulina, in British Columbia

1990 ◽  
Vol 47 (5) ◽  
pp. 992-1003 ◽  
Author(s):  
Peter F. Olesiuk ◽  
Michael A. Bigg ◽  
Graeme M. Ellis
Keyword(s):  
British Columbia ◽  
Vancouver Island ◽  
Phoca Vitulina ◽  
Primary Study ◽  
Relative Distribution ◽  
Strait Of Georgia ◽  
Queen Charlotte Islands ◽  
Harbour Seals ◽  
Recent Trends ◽  
Skeena River

Aerial censuses of harbour seals (Phoca vituiina) were conducted in the Strait of Georgia (1966–88), the lower Skeena River (1977–87), off the southwest coast of Vancouver island (1976–87), off the northeast coast of the Queen Charlotte Islands (1986), in Jervis Inlet (1987), and at the entrance to Queen Charlotte Strait (1988). The estimated number of seals in the Strait of Georgia, the primary study area, increased from 2170 in 1973 to 15 810 in 1988; the number in the lower Skeena River from 520 in 1977 to 1590 in 1987; and the number off south western Vancouver Island from 210 in 1976 to 1130 in 1987. The trends indicated that populations throughout British Columbia had been increasing at a rate of about 12.5% ∙yr−1 since 1973. Based on the density of seals in the areas surveyed, and the relative distribution of bounty and commercial kills, the total post-pupping population in British Columbia was estimated to have numbered 75 000–88 000 in 1988, compared with 9000–10 500 when the species was protected in 1970. Despite the recent increases, which probably reflect the recovery from historic kills, there was no evidence of density-dependent changes in the population growth rate.

Late-glacial and postglacial vegetation history at Bear Cove Bog, northeast Vancouver Island, British Columbia

1983 ◽  
Vol 61 (12) ◽  
pp. 3172-3192 ◽  
Author(s):  
Richard J. Hebda
Keyword(s):  
British Columbia ◽  
Forest Canopy ◽  
Vegetation History ◽  
Late Glacial ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Pteridium Aquilinum ◽  
Thuja Plicata ◽  
Blanket Bog

At 13 630 ± 310 BP (WAT-721) Port Hardy is the earliest area known to have been deglaciated at the end of the Fraser Glaciation on Vancouver Island. Pollen and macrofossil analyses of two cores from a basin–blanket bog show that about 14 000 years ago Pinus contorta, Alnus, and Pteridium aquilinum formed pioneering vegetation typical of post-ice environments on the Pacific Northwest coast. Climate is interpreted to have been relatively cool and dry. Picea sitchensis – Tsuga mertensiana forest succeeded at about 11 500 BP and persisted until about 10 000 BP. Climate was cool, moist, and maritime. Warming at about 10 000 BP permitted Tsuga heterophylla gradually to replace T. mertensiana. At 8800 BP Pseudotsuga menziesii migrated into the area and together with P. sitchensis dominated the forest. Abundant Pteridium aquilinum spores suggest forests were open. During the interval 8800 to 7000 BP the climate was warmer and drier than at present because today forests with Pseudotsuga do not extend as far north as Port Hardy. During this warm time, shallow ponds dried out. By 7000 BP Pseudotsuga declined and T. heterophylla and P. sitchensis dominated forests. Climate became wetter and cooler than in the preceding period but not as cool as today. About 3000 BP Cupressaceae, presumably both Thuja plicata and Chamaecyparis nootkatensis, shared the forest canopy with T. heterophylla. Sphagnum growth and bog development occurred after 7000 BP as climate became moister. The vegetation sequence described is a "maritime" type similar to sequences on the west coast of Washington State but unlike those from the Fraser Lowland. The xerothermic interval was of short duration between 8800 and 7000 BP but was expressed clearly in this area of moist maritime climate and therefore must have been of considerable amplitude. Vegetation differences between coastal and inland southwestern British Columbia were established by 11 500 BP.

The plainfin midshipman’s soundscape at two sites around Vancouver Island, British Columbia

2018 ◽  
Vol 603 ◽  
pp. 189-200 ◽  
Author(s):  
WD Halliday ◽  
MK Pine ◽  
APH Bose ◽  
S Balshine ◽  
F Juanes
Keyword(s):  
British Columbia ◽  
Vancouver Island
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