Queen Charlotte Islands margin

2015 ◽  
pp. 403-411 ◽  
Author(s):  
Robin Riddihough ◽  
Roy D. Hyndman
1994 ◽  
Vol 25 (2) ◽  
pp. 231
Author(s):  
Carol M. Eastman ◽  
Douglas Cole ◽  
Bradley Lockner ◽  
George Dawson

1981 ◽  
Vol 18 (4) ◽  
pp. 776-788 ◽  
Author(s):  
R. D. Hyndman ◽  
R. M. Ellis

A temporary array of land and ocean bottom seismograph stations was used to accurately locate microearthquakes on the Queen Charlotte fault zone, which occurs along the continental margin of western Canada. The continental slope has two steep linear sections separated by a 25 km wide irregular terrace at a depth of 2 km. Eleven events were located with magnitudes from 0.5 to 2.0, 10 of them beneath the landward one of the two steep slopes, some 5 km off the coast of the southern Queen Charlotte Islands. No events were located beneath the seaward and deeper steep slope. The depths of seven of these events were constrained by the data to between 9 and 21 km with most near 20 km. The earthquake and other geophysical data are consistent with a near vertical fault zone having mainly strike-slip motion. A model including a small component of underthrusting in addition to strike-slip faulting is suggested to account for the some 15° difference between the relative motion of the North America and Pacific plates from plate tectonic models and the strike of the margin. One event was located about 50 km inland of the main active zone and probably occurred on the Sandspit fault. The rate of seismicity on the Queen Charlotte fault zone during the period of the survey was similar to that predicted by the recurrence relation for the region from the long-term earthquake record.


1984 ◽  
Vol 62 (9) ◽  
pp. 1968-1970 ◽  
Author(s):  
William G. Roland ◽  
L. Michael Coon

Recovery of intertidal Porphyra beds following hand harvest was studied near the northwest tip of the Queen Charlotte Islands, B.C. Twenty-six percent of the standing crop of Porphyra perforata J. Ag. was removed in a large plot in June 1981; no negative effect on standing crop was apparent in May 1982 as compared with the adjacent control area. There was no negative impact on percent cover of Porphyra (mostly P. perforata) within 1 year after hand harvest of seven, approximately 1-m2 plots, as compared with respective controls. Annual fluctuation in cover, biomass, and relative mix of Porphyra species was large. Porphyra cover in a small plot harvested in early June 1981 increased to 86% of the June value by mid-July 1981, indicating substantial growth of the remaining thallus fragments and small, whole plants within one season. It was concluded that sustained yield of Porphyra beds can be assured if harvest is restricted to gathering by hand.


The Auk ◽  
1916 ◽  
Vol 33 (4) ◽  
pp. 420-423 ◽  
Author(s):  
J. H. Fleming

2007 ◽  
Vol 29 (3) ◽  
pp. 219-239 ◽  
Author(s):  
T. D. Peterson ◽  
H. N. J. Toews ◽  
C. L. K. Robinson ◽  
P. J. Harrison

1888 ◽  
Vol 5 (8) ◽  
pp. 347-350 ◽  
Author(s):  
Geo. M. Dawson

Previous observations in British Columbia have shown that at one stage in the Glacial period—that of maximum glaciation—a great confluent ice-mass has occupied the region which may be named the Interior Plateau, between the Coast Mountains and Gold and Eocky Mountain Kanges. From the 55th to the 49th parallel this great glacier has left traces of its general southward or southeastward movement, which are distinct from those of subsequent local glaciers. The southern extensions or terminations of this confluent glacier, in Washington and Idaho Territories, have quite recently been examined by Mr. Bailley Willis and Prof. T. C. Chamberlin, of the U.S. Geological Survey. There is, further, evidence to show that this inland-ice flowed also, by transverse valleys and gaps, across the Coast Range, and that the fiords of the coast were thus deeply filled with glacier-ice which, supplemented by that originating on the Coast Range itself, buried the entire great valley which separates Vancouver Island from the mainland and discharged seaward round both ends of the island. Further north, the glacier extending from the mainland coast touched the northern shores of the Queen Charlotte Islands.


1985 ◽  
Vol 22 (3) ◽  
pp. 416-421 ◽  
Author(s):  
J. H. Sass ◽  
L. A. Lawver ◽  
R. J. Munroe

Heat flow was measured at nine sites in crystalline and sedimentary rocks of southeastern Alaska. Seven of the sites, located between 115 and 155 km landward of the Queen Charlotte – Fairweather transform fault, have an average heat flow of 59 ± 6 mW m−2. This value is significantly higher than the mean of 42 mW m−2 in the coastal provinces between Cape Mendocino and the Queen Charlotte Islands, to the south, and is lower than the mean of 72 ± 2 mW m−2 for 81 values within 100 km of the San Andreas transform fault, even farther south. This intermediate value suggests the absence of significant heat sinks associated with Cenozoic subduction and of heat sources related to either late Cenozoic tectono-magmatic events or significant shear-strain heating. At Warm Springs Bay, 75 km from the plate boundary, an anomalously high heat flow of 150 mW m−2 can most plausibly be ascribed to the thermal spring activity from which its name is derived. At Quartz Hill, 240 km landward of the plate boundary, a value of 115 mW m−2 might indicate a transition to a province of high heat flow resulting from late Tertiary and Quaternary extension and volcanism.


Sign in / Sign up

Export Citation Format

Share Document