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1.
Seabird colonies were censused during the summer expedition of Norsk Polarinstitutt to Nordaustlandet, Svalbard, in 1978 and 1979, and to Kongsøya in 1979. An outline is given of the distribution of the species together with an estimate of the number of breeding pairs in the colonies. Twentv-five colonies were censused; seven were visited both years. Four colonies with more than 1,000 breeding pairs of the most abundant species, Briinnich's guillemot and kittiwake, were found on Nordaustlandet.  相似文献   

2.
Three well-developed raised marine shorelines along Nordenskioldkysten have been studied and correlated with the shoreline displacement since the last deglaciation. The marine limit of 64 m in the area is of Late Weichselian age and has been dated to 10, 900- 11, 000 years B.P. An intermediate level at 50 m is estimated to be 10, 600-10, 000 years old and demonstrates a sea level stagnation probably caused by a glacier readvance in eastern Svalbard during the Younger Dryas. A Holocene transgression culminating shortly after 6, 000 years B.P. has been stratigraphically demonstrated, and it probably correlates with the Tapes transgression of Scandinavia. No pre-Late Weichselian marine levels are found, and the large rebound can be attributed only to a Late Weichselian glaciation.  相似文献   

3.
Food samples from six high-arctic seabird species were collected during spring and summer seasons between 1982 and 1990 in the Svalbard region. The material came from coastal localities on the island of Spitsbergen and the marginal ice zone in eastern Svalbard waters. Polar cod Boreogadus saida was the most frequently occurring prey in the ice-covered areas. Analysis of otoliths showed that most polar cod were one-or two-year olds. These year classes are known to associate with sea ice. Other ice-associated (sympagic) organisms, such as gammarid amphipods, were not found to be of high importance as prey for seabirds in the study area. However, the sea ice occurring in the area was mainly one year old. Such ice contains a less developed sympagic fauna than multi-year ice. The pelagic amphipod Parathemisto libellula , which is not sympagic but occurs in the water column, was also found to be an important prey in the marginal ice zone, especially for the Briinnich's guillemot Uria lomuia . The smallest of the seabird species studied, the little auk Alle alle , differed from the other five species in its diet, preying mainly upon smaller items such as copepods and young stages of amphipods, euphausiids and decapods. The diet of the various seabird species was in general more diverse in the coastal areas than in the marginal ice zone.  相似文献   

4.
This short paper aims to discuss the role and the importance of the Census in New Zealand. It also discusses some of the multitude of uses of Census data in various contexts to help us understand the demographic and socio‐economic landscape of New Zealand. Debates internationally on the nature, scale and frequency of a national Census, or even whether a Census is necessary at all, mean that we cannot take this valuable resource for granted. With this in mind, we as geographers have a wealth of data to explore and analyse that we should take full advantage of. What gets counted counts!  相似文献   

5.
A survey on the Common Eider Somateria mollissima in wing-feather moult and females with young was carried out in connection with Norsk Polarinstitutt's expedition to Svalbard in July and August 1979. A total of 3450 moulting eider were found on a water area of approximately 2500 km2; 18% of these were flightless. Females dominated in the population with about 82%. Of the breeding population, 109 females with 336 young were found. The average ratio of female to young has been calculated at 1:3.08. This ratio in relation to other studies of eider productivity is discussed briefly.  相似文献   

6.
This study was conducted in Kongsfjorden, Svalbard, from mid-March through April 1984. Local Greenland sled dogs were used to locate subnivean ringed seal lairs. A total of 90 lairs were found and excavated. These constituted 28 lairs classified as birth lairs, 22 as tiggak (rutting male) lairs, and 40 which could not be classified. The first birth lair was found on 24 March. There was significantly more snow covering birth lairs than tiggak lairs, and birth lairs were also shown to be significantly larger than tiggak lairs. The positions of the lairs were plotted on a map, and distances between neighbouring seal lairs were used as an indicator of territorial size. Arctic foxes had attacked 19 lairs and 6 of these had resulted in a kill (32%). Polar bears had attacked 13 lairs with one kill (8%).  相似文献   

7.
8.
Five species of guide fossils from the Holocene warm period in Svalbard are considered: Mytilus edulis, Modiolus modiolus, Arctica islandica, Littorina littorea and Zirphaea crispata . These are now extinct in Svalbard; Zirphaea crispata , especially, requires considerable higher water temperatures than occur there today. Known radiocarbon dates on Mytilus, Modiolus and Zirphala are given. Thirty-four dates on Mytilus edulis show that it lived in Svalbard from before 9500 BP to about 3500 BP, and probably again around 1000 BP. Five dates on Modiolus and Zirphaea indicate a climatic optimum in Svalbard from about 8700 BP to 7700 BP. The most favourable places then had conditions similar to the northeastern coast of Finnmark, northernmost Norway, today. Mytilus edulis is considered a good climate indicator, and a future warming of the marine climate in Svalbard could be indicated by its eventual re-immigration into the area.  相似文献   

9.
Two of Svalbard' Trollkjeldane (Troll Springs) have a luxuriant vegetation of charophytes. This article is based on material collected in the Trollkjeldane by Sissel Aarvik, of the Office of the Sysselmann (Governor) of Svalbard, on 28 August 1992 and 16 August 1993. Chara canescens is described, based on living material. The Svalbard specimens have been named Chara canescens f. spitsbergensis comb. nov., which is synonymous with Chara aspera f. spitsbergensis Nordstedt. An imperfect charophyte is described here as a new subspecies of C. canescens: Chara canescens subsp. hoelii, named after Adolf Hoel, who first collected specimens of this subspecies. It is believed that this subspecies originates from Chara canescens, presumably by a genetic reorganization or a mutation of the species. A new subspecies is justified because of the ecorticate internodes, the incomplete or lacking cortex of the branchlets, the occurrence of accessory branchlets and the special bulbils found in this taxon. These are interpreted as characteristics with positive selective value in the special environment of the spring, where asexual reproduction by bulbils presumably has the same selective value as the parthenogenic reproduction by oospores in Chara canescens f. spitsber- gensis.
In a growth experiment, the best growth of C. canescens f. spits- bergensis from the springs was obtained in water with relatively low salt content.
Growing tourism in Svalbard threatens to the springs; more active protection must be evaluated. There is also an urgent need to survey the springs in more detail.  相似文献   

10.
11.
OLA EIKEN 《Polar research》1985,3(2):167-176
The status of seismic exploration work mapping the post-Caledonian strata in the Svalbard area is presented. Compressional wave velocities are very high throughout the area, around 4km/s in the Tertiary and Mesozoic layers. In the Permian section velocities exceed 5 km/s, with refraction velocities > 6 km/s in the calcareous rocks of the Gipsdalen Group (early Permian/Late Carboniferous). Apart from correlation with carbonate and chert lithology, high velocities reflect the high degree of consolidation and the low porosities of shales and sandstones in the post-Caledonian strata in Svalbard. In van Mijenfjorden seismic reflection events are observed down to 3–4 km depth and associated with Carboniferous and younger strata. The thickness of the Mesozoic layers in this part of the central Spitsbergen syncline seems to be greater than previously suggested, and there is an apparent eastward divergence between the Jurassic and the Triassic reflectors. In south-western Storfjorden, reflections interpreted to originate from Carboniferous and Permian strata might represent the seaward extension of the central Spitsbergen syncline. In the northern part of Storfjorden, carbonate layers within the Gipsdalen Group are interpreted to lie about one kilometre below the sea floor. A prominent fault zone in this area trends NNW-SSE, like the main structural elements on Spitsbergen. It shows block-faulting, presumably caused by extensional movement in late Devonian-Carboniferous time.  相似文献   

12.
Sediment cores collected from eight lakes along the western coast of Svalbard as part of a project investigating atmospheric pollution and environmental change in Arctic regions were dated radiometrically using natural (210Pb) and artificial (137Cs and 241Am) fallout radionuclides. At four sites the sedimentation rates were relatively uniform, and in consequence the 210Pb dates were relatively unambiguous. At the remaining sites there were irregularities in the 210Pb activity versus depth profiles, indicating significant variations in the net sediment accumulation rate during the past 120 years. At these sites, there were significant differences between 210Pb dates calculated using the two standard simple dating models, constant rate of supply (CRS) and constant initial concentration (CIC). In most cases, stratigraphic dates based on the 137Cs and 241Am records supported use of the CRS model, though at one site (Ossian Sarsfjellet) the CIC model appeared more appropriate. The irregularities in the 210Pb records were mainly caused by episodes of accelerated sedimentation due, for example, to inwash or slump events, though at some sites there appears to have been a systematic increase in sediment accumulation rates in recent decades. Sediment accumulation rates were generally lower at the northern sites, and higher at the more southerly locations. Mean sediment accumulation rates varied by an order of magnitude, ranging from 0.002 to 0.050 g cm−2 y−1 (0.02–0.10 cm y−1). 210Pb fluxes measured from the core inventories were mostly in the range 34–80 Bq m−2 y−1 typical of Arctic sites. Much higher values, recorded at two sites (Birgervatnet and Daltjørna), may be due to significant inputs from the catchments during spring thaw.  相似文献   

13.
Seabirds of high latitudes in the North and South Atlantic (chiefly penguins, Procellariformes, alcids, shags, Gannet and Kittiwake) are compared (on absolute and energy-, mass- and time-specific scaled bases) in terms of the rate at which they supply energy to their offspring, the rate of offspring growth, and the duration of the dependence (fledging) period. For a smaller suite of species, time and energy budgets during complete foraging cycles (including time ashore) and while at sea are compared. The broad-scale comparisons show storm petrels to have consistently low provisioning and growth rates, and Kittiwakes, Gannets, shags and some penguins to have consistently high rates. Penguins (except the Gentoo Penguin) and albatrosses spend most of a foraging cycle at sea; murres, shags, gannet and kittiwake spend at least half the time ashore, guarding their offspring. Energy budgets are much more similar, because of the disproportionate cost of at-sea activities, although the time spent flying, swimming, resting, and diving varies widely between species and is often difficult to interpret in terms of active foraging. Other apparent anomalies include the large amount of time Common Murres spend resting at sea and the high resting and low flight metabolic rates of kittiwakes and gannets. Assessments of foraging performance need to be more broadly based than hitherto and to take account of both physical constraints and ecological contexts. Further development of these approaches, especially critical interspecies comparisons, requires better discrimination of activities at sea, measurement of activity-specific energy costs and more accurate data on provisioning rates to offspring, particularly of North Atlantic species, notably Gannets and shags.  相似文献   

14.
Above the marine limit in Gangdalen, Nordenskiold Land, a 20 m thick sequence of unconsolidated sediments occurs. On the top of striated bedrock it is composed of a 2m thick till bed, 15m gravel interpreted to be deposited as a sandur, and another till bed on the top. A solifluction deposit is capping the section. Fabric analyses and erratics in the two tills indicate a similar development in glacial transport directions during the two glaciations, starting with a local glaciation which subsequently turns into a larger glaciation centred over the eastern part of Svalbard. Co-existence of different ice domes over Spitsbergen is suggested. The sandur was deposited during an ice free period with a sea-level 40–80 m higher than at present. The section is undated.  相似文献   

15.
16.
Two censuses made of the population of Svalbard reindeer on Edgeøya in 1983 and 1996 resulted in 1586 and 2434 individuals respectively. Together with data from earlier population surveys (1969-77), this indicates, numerically, a population growth during the period 1969-96. Because of the weaknesses in the different census methods used, we cannot conclude that in reality a population growth has taken place even though the numerical data is correct. Therefore an average population size of 1730 (± 451 SD) individuals for the period 1969-96 is suggested. Earlier estimates of vegetated area indicate that the present data corresponds to reindeer densities averaging 1.05 and ranging from 0.79 to 1.47 individuals/km2.  相似文献   

17.
Palynological investigations of 16 sections from Spitsbergen, Svalbard, covering the uppermost Carboniferous, Permian and lowermost Triassic succession have been carried out. Because of general poor preservation and barrenness of the majority of the samples, it was not possible to establish a formal zonation for the Permian succession. The study resulted, however, in the recognition of three Permian palynological assemblages, restricted downwards by a Carboniferous assemblage and upwards by an earliest Triassic (Griesbachian) assemblage. The dating of these assemblages is based on palynological correlation with similar palynofloras elsewhere in the present Arctic region as well as dating by marine faunas, which in general give better stratigraphic resolution. The Permian assemblages recognised include (1) the Vittatina assemblage of late Gzhelian to early Asselian age recorded in the lower parts of the Tyrrellfjellet Member (Nordenskioldbreen Formation), (2) the Hamiapollenites tractiferinus assemblage of late Asselian to Artinskian age recorded in the upper parts of the Tyrrellfjellet Member and in the Gipshuken Formation and (3) the youngest Permian Kraeuselisporiles assemblage of late Artinskian to earliest Tatarian age recorded in the Kapp Starostin Formation.  相似文献   

18.
19.
Polar bear predation on ringed seals in the fast-ice of Hornsund, Svalbard   总被引:1,自引:0,他引:1  
Polar bear hunting success on ringed seals in subnivean lairs and basking on the fast ice, was studied in Hornsund, Svalbard. A few bears were observed while actually hunting, but in most cases bear tracks were followed by snowmobile to determine the outcome of hunts. Seal carcasses were classified from size and tooth annuli as pups, juveniles or adults. A total of 62 subnivean structures were entered by bears, with six seals killed. One of ten charges on basking seals resulted in a kill. Success rates of bears in Hornsund arc compared with results of studies in Canada and Svalbard. OHunting success, polar bear, predation, ringed seal  相似文献   

20.
A renewed survey of the flora of Bjornoya (74° 31'N) has yielded a total of 54 native vascular species. Details of their distribution are provided by local maps and vertical frequency tabulations. Soil preferences of species and various plant communities are outlined. The general climate and microthermal conditions of the prevailing vegetation place Bjerneya as a pronouncedly maritime part of the Svalbard archipelago, supporting mainly hygrophilous and chionophilous plant communitites and species. Only half of the island's vascular species persist at elevations above 200 m a.s.l., corresponding to a heat sum of July and August below approximately 190 Degree-Days. Ice-cored peat mounds coated by Rhacomitrium lanuginosum were discovered on plateaux above 400 m elevation.
The impact of the Vistula glaciation is discussed in view of Quaternary evidence from the Barents Sea area. Probably only one third of the present vascular flora could endure full-glacial conditions in possible ice-free cliffs on the coast of Bjornaya.  相似文献   

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