String-Bogs in the Arctic 400 Miles North of the Tree-Line

Abstract

With rapidly expanding economic activity in the Arctic and Subarctic, knowledge of th influence of terrain, soil and vegeta ion characteristics on construction and communication is of increasing importance. Radforth (1959, p. 50) warns, for example, that muskeg presents such formidable difficulties to transportation that it might . . plunge the oil industry into type of financing that contemporary economics will label prohibitive. Similarly, the discussion on the distribution and origin of string-bogs, especially the comments of Williams (1959) on the note of (1958), indicates the need for further study of the problem, if only because of the suggestion that they can be taken as an indication of the presence or absence of permafrost, which wrongly interpreted might have disastrous results to construction. Drury (1956, p. 119) defines strangmoor which is synonymous with as a bog on whose surface are patterns, festoons or nets of vegetation growing on mossy ridges between which are present patches of standing water or sedge meadow.,, On the subject of the distribution of string-bogs, Williams (1959, p. 145) relates that Troll (1944) has pointed out that they are restricted to areas with continental climate of only moderate cold, lying outside the region of continuous permafrost.'' Drury (1956, p. 52), on the basis of his observations in Eastern Canada and Alaska, agrees with Troll that: liStrangmoor is phenomenon of the region just south of continuous At least their distribution coincides with the northern edge of boreal forest, which within 200-mile limits corresponds with the limit of con? tinuous permafrost. Hamelin (1957) finds string bogs in the Quebec-Labrador peninsula, south of the line of continuous permafrost, restricted to the zone with the southern limit of the 50th parallel and northern limit of the 55th parallel. Allington (1958, p. 91), on the basis of her studies of bogs in central Labrador, defines them as related genetically to seasonally frozen ground and not to permafrost, which in this area occurs in palsas only. Patterned fens, which are form of string-bog, are described by Sjors (1959) from the Hudson Bay lowlands where permafrost is again restricted to palsas. Williams (1959) supports the view of Troll, and concludes that Mackay must be referring to different features of localized occurrence when mentioning string-bogs on Cornwallis Island. On the other hand, ridges and hummocks described by Hanson in the Kotzebue area in Alaska appear to be similar to string-bogs and were found on permanently frozen ground with an active layer ranging in depth from 10-5 to 27 inches (1950, p. 624). The writer, while working on King William Island and Adelaide Peninsula, N.W.T., for the Geographical Branch, Department of Mines and Technical Surveys, in the summer of 1956, observed numerous staircase ponds, thrust ponds and stringbogs. Both King William Island and Adelaide Peninsula have been glaciated and subsequently submerged, the surface material reflecting this history (see Fig. 1). The shape of the features observed on Adelaide Peninsula fits the description of most string-bogs, but in this area mineral soil is incorporated in their structure, and there were many indications that vegetation was not prerequisite in their formation. They form peculiar pattern which resembles fingerprints on the aerial photographs of the area. These features appear to be string-bogs, but they do not indicate areas free of permafrost, as Adelaide Peninsula lies well within the zone of continuous permafrost and about 400 miles north of the tree line. It is an area of extreme cold, with mean annual minimum temperature of ? 500 F. and mean annual precipitation of only 6