Describes structural and vegetative features of bogs and fens in the peatlands area south and west of Hudson Bay, examined in summer 1957 mainly near the confluence of the Attawapiskat and Muketei Rivers (approx. 53 N, 86 W). Distinctive features of the ridge-shaped raised bogs are their undulating surfaces, large shallow pools, and lateral seepages (small, shallow pools termed flarks, in a stepped arrangement down the bog edges). Bog vegetation, typical of ombrotrophic peatlands, is acidophilous and low in pH value except in limited areas, e.g. fissures caused by frost heaving where fen plants are found, also the lateral seepages where patches of true fen vegetation appear along the rows of flarks. The plant communities are almost identical with those of similar raised bogs in Sweden and Finland. Fen surfaces are covered by large pools, and alternating low ridges low ridges and flarks. The fen water is highly minerotrophic, resulting in vegetation richer in mineral nutrients than that of the bogs, and similar to the "rich fen" or "brown fen" vegetation of Scandinavia. Roundish "black-spruce islands" are conspicuous fen features; they have permafrost cores as do knolls (palsas) north eastward near Sutton and Hawley Lakes.
Reports investigations of dome-shaped shelters constructed in Alaska during winter 1955-56, some of loose, unconsolidated snow at the Arctic Aeromedical Laboratory, near Fairbanks, others of snow blocks on sea ice at Barter Island (70 08 N, 143 40 W). Pneumatic forms such as inflated weather balloons were useful, but not indispensable, in the loose snow type. Due to compaction, the density of the snow increased during construction from 0.22 gm/cu cm to 0.28 gm/cu cm and the hardness range from 8-80 gm/sq cm to 200-850 gm/sq cm Air temperatures in and outside both occupied and unoccupied shelters of this type (tabulated) demonstrate the efficacy of snow as an insulator and thermal advantages derived from ground heat. Inside temperature close to that at the ground surface, remained nearly constant (15-20 F) while outside temperatures ranged from -12 to -40 F Shelters were warmer during occupancy. In the snow-block shelters built on bare sea ice and on an 18 in deep drift, temperatures varied from 10-19 F at the top, 7-20 F in the center, and 7-18 F at the floor, while outside temperatures ranged from -2 to -5 F; thus subnivean warmth on sea ice can also be utilized. The temperature in a 2.5 ft deep trench in a drift, covered with a roof of horizontal snow blocks, was 20-24 F at the sleeping level 6 in above the floor.
Reviews post-war studies on the secular motion of the dip pole and predicts its position for epoch 1960. 0:74.8 ± 0.3 N., 99.6 ± 1.2 W. The daily track during moderate magnetic disturbance approximates an ellipse with a north-south long axis of ca. 30 mi and an east-west axis of ca. 18 mi. Estimated and observed tracks 1600-1950 are mapped, and sources and magnitudes of errors are discussed. The secular motion, as estimated by various methods, averages 5.5 mi/yr to the north and 0.7 mi/yr to the east.
Investigates freeze-thaw cycles (a rise to 34 F following a drop to 28 F) as a cause of rock disintegration by comparing their frequencies in northern and southern Canada. Cycles counted at 42 weather stations showed an increase from north to south: nine at Eureka on Ellesmere Island in 1949 as compared with 74 at Regina, Saskatchewan. Correlation between the freeze-thaw frequencies and diurnal temperature range is indicated; average at Eureka is 12 F at Regina 24 F. The greater evidence of rock disintegration in northern Canada therefore does not result from lower temperatures or freeze-thaw frequency. Other explanations are offered.
During the months June to September 1958 the estuary of False River, Ungava Bay, was examined in the course of a study of the biology of the amphipods Gammarus oceanicus and G. setosus and the conditions of their shore environment. This work will be reported in detail when completed. The following is a general account of the area. The estuary itself can be divided into three components: the seaward arm is a wide shallow area running generally southward to a group of islands and the major tributary stream on the east bank; then follows a narrow deep arm running to the southwest and opening finally into the striking expanse of mud and boulders known as Kohlmeister Lake. ... Tidal currents were sufficiently strong to discourage more than one attempt at anchoring a canoe in mid-stream for measuring purposes. ... Sharp salinity and temperature fronts were observed moving up and down the estuary, and it seems that the central basin acts as a mixing reservoir receiving water from the north and south arms alternately. ... No evidence was found for deoxygenation in deeper waters; values obtained ranged from 7.1 to 8.1 ml. of oxygen per litre. ... Trees reach their definite limit along a line running northeast from the head of Kohlmeister Lake where there are some quite thick woods. Perhaps the most interesting aspect of the local flora is the extensive development of salt-marsh vegetation. ... During the summer only one lemming was seen, but evidence of much previous [mammal] activity was noticed. ... Seals were occasionally seen throughout the length of the estuary, but the greatest concentrations occur about the seaward parts of False River. Among the birds ptarmigan were particularly abundant in the vicinity of the base camp on the main eastern tributary of the estuary .... Of particular interest was the occurrence of frogs, tentatively identified as Rana sylvatica, in certain shallow pools at the extreme upper limit of spring tides on the salt flats of Kohlmeister Lake. ... Some two hundred fish were measured and examined in detail by my companion Mr. P. M. Gillespie who found them generally and heavily infested by gut and body parasites, and during a trip to George River copepod gill parasites were found in 70 per cent of the arctic char. In this connection it was interesting to observe that up to 40 per cent of the two Gammarus species on which this work centred were infected with the intermediate stages of as yet undetermined intestinal parasites of vertebrates. A few specimens of G. oceanicus were found to contain a single huge, apparently neotenous cestode, which virtually filled the body cavity. Gammarus will be worth examining in any investigation of parasite problems of the many fish, seals, and birds that feed on it. ...