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1.
Four relative sea-level curves from Edgeøya and Barentsøya are constructed based on 81 radiocarbon age determinations on carefully selected and levelled samples in raised beaches, mostly driftwood embedded in beach gravel. All the dates, covering the period from the deglaciation to the present, are calibrated to calendar years, and the sea-level curves are defined by fitting the data with a least square regression curve. The dates are internally very consistent, and the results are some of the most precise sea-level curves from the Arctic.
The four curves are quite similar, and from the marine limit at 85-90 m a.s.l. they show a rapid emergence (ca 40 mm/year), formed about 11,000 cal yrs BP (∼10,00014 C yrs BP). A minimum rate of emergence close to 8000 cal years ago is explained by a decreased rate in isostatic uplift parallel with a sustained rate of eustatic sea-level rise. During the last 7000 cal years, the emergence rate has decreased linearly. The uplift rates have been slightly higher on southern Edgeøya than further north during the last 7000 years. By comparing the sea-level curves from Storøya (ca 270 km to the north) and Hopen (ca 150 km to the south), we suggest that a memory of an earlier and larger glacio-isostatic downwarping in the southern Barents Sea is detected in the sea-level curves from Hopen and southern Edgeøya. 相似文献
The four curves are quite similar, and from the marine limit at 85-90 m a.s.l. they show a rapid emergence (ca 40 mm/year), formed about 11,000 cal yrs BP (∼10,000
2.
ERIK SKYE 《Polar research》1986,4(1):69-78
The vascular plant flora of the small arctic island of Hopen, located in the Barents Sea, was inventoried during a visit in the summer of 1982. Eighteen vascular plant species were observed and mapped, and the vegetation described. 相似文献
3.
In 1988, first-year Herring Clupea harengus were the dominant prey fed to Puffin chicks on Hernyken, Røst. Puffins carrying food loads were observed at least 137 km from the colonies in July. In early August, two major feeding areas were located about 20 and 85-105 km off Røst. These long foraging ranges and an insufficient availability of food are thought to be the main reasons for the poor chick growth this year. No relationships were found between the distribution of Puffins observed at sea and survey station data on prey distribution, sea temperature or salinity, but this may have been due to inadequate sampling of these parameters. A recorded seasonal change in flight direction of adults returning to colony is discussed in relation to food quality and chick growth. 相似文献
4.
Concentrations (ppm = ug/g dry weight) of total mercury (Hg) were determined in hair of polar bears ( Ursus maritimus) from northwestern Greenland (N = 22; period of sampling: 1978-1989), eastern Greenland (N = 44: 1984-1989) and Svalbard (N = 31; 1980). For subadults (2-6 years of life), adults (7-10 years). and old bears (>10 years), concentrations of total Hg in hair were not found to be dependent on age or sex. A decreasing trend in Hg concentrations was found from west to east. The mean concentrations of total Hg in hair (cubs of the year and yearlings excluded) were: northwestern Greenland, x = 8.38 ppm (min.-max.: 4.71-14.19 ppm. N = 21); eastern Greenland: x = 4.58 ppm (min.-max.: 2.50-8.83 ppm. N = 41); and Svalbard, x = 1.98 ppm (min.-max.: 1.02-4.55 ppm, N = 29). Concentrations found in northwestern Greenland were similar to those reported by others from the hair of polar bears sampled within management zone F of the eastern Canadian High Arctic. Concentrations of total Hg in polar bear hair from eastern Greenland were similar to concentrations found by others in contemporary (1988) material collected during spring in western Svalbard. However, the mean concentration of total Hg in the 1980 Svalbard material, which was collected during July-September, was significantly lower than concentrations found in samples taken during late winter and spring in eastern Greenland and at Svalbard, respectively. Presumably the relatively low concentrations found in the 1980 Svalbard sample arc attributable to the period of moult and hence a larger proportion of newly grown hair in the individual samples. In a subsample consisting of internal tissues from 19 polar bears from eastern Greenland (1984-1987), concentrations of total Hg in hair correlated positively with concentrations of total Hg (wet weight) in muscle (N = 6), liver (N = 19) and kidney (N = 19) tissue. For liver and kidney tissue these relationships were statistically significant. 相似文献
5.
Remote sensing of the ice cover in Storfjorden (Svalbard) revealed the persistence and evolution of latent heat polynyas during the winter of 1997/98. Latent heat polynyas open mechanically under wind stress or ocean currents that transport the ice cover away. In the present work we used mathematical modelling to simulate the Storfjorden polynya size and geometry caused by wind stress, measured at the meteorological station on the island of Hopen in winter 1997/98. The dependence of the polynya outlines on the wind velocity is presented. Two approaches were used: quasi-static and dynamic. Quasi-static simulations are based on a time-independent, linear ice stress-strain relationship valid for the low strain rates only. Time dependence of the ice cover fracture is joined with stress-strain nonlinearity caused by ice delayed-elastic recovery and viscosity. Results are compared to satellite observations from the synthetic aperture radar (SAR) of ERS-2. The simulation results show that a northern wind opens a larger polynya (ca. 30%) than does a north-eastern wind with the same speed. The results also indicate that the bathymetry and geometry of the fjord might have a stronger influence on the polynya opening and development than the location of individual islands and reefs. 相似文献
6.
Seasonality in an Arctic fjord ecosystem: Hornsund, Spitsbergen 总被引：3，自引：0，他引：3
J. M. WS&#;AWSKI M. ZAJACZKOWSKI S. KWA&#;NIEWSKI J. JEZIERSKI W. MOSKAL 《Polar research》1988,6(2):185-189
Based on two complete years of marine ecological surveys (1981-82 and 1984-85) carried out in the Hornsund fjord on southern Spitsbergen (77N), the seasonal variation of physical and biological processes is presented. Physical parameters reflect the strong seasonality of sun radiation, while water salinity and temperature fluctuate within a narrow range. Concentrations of nutrients and suspended matter depend on meltwater discharge from glaciers and snow cover thickness. The breeding period of most marine invertebrate species is strongly related to the phytoplankton bloom which peaks in May. Ringed seal and polar bear occurrences are directly related to sea ice conditions. Both species are most numerous in Hornsund during March-April. Sea birds which nest in huge colonies along the Hornsund coasts arrive in April-May and leave by August-September except for Fulmars and Brünnich's Guillemots which were observed year-round. 相似文献
7.
ARNE HASSEL HEIN RUNE SKJOLDAL HARALD GJØSÆTER HARALD LOENG LENA OMLI 《Polar research》1991,10(2):371-388
The distribution of capelin was mapped in the area east of Hopen. Zooplankton was sampled with Juday net and 1 m2 MOCNESS sampler, and analysed with respect to hydrography and capelin abundance. The capelin "front" coincided more or less with the physical Polar Front, and this complicated the interpretation of the results. Strong indications for a grazing impact by capelin on zooplankton were nevertheless obtained. The zooplankton biomass was significantly lower in the area with high abundance of capelin than in the area with no capelin. This effect was due to a lower biomass of relatively large zooplankton (> 1 mm size fraction) and seen most clearly in data obtained with the MOCNESS. The biomass of zooplankton in the upper 100 m was very low where capelin was present, suggesting rapid depletion of the major prey items. The biomass (m −2 ) of capelin in the capelin front area was about three times higher than the biomass of zooplankton in areas without capelin. The capelin front would therefore have the potential to graze down the available prey in 3-4 days. Light seems to be an important factor for the predation impact by capelin, resulting in strong interactions between capelin predation and zooplankton vertical distribution. 相似文献
8.
Ecological differences of south polar skua populations from Fildes Peninsula of King George Island and eastern Larsemann Hills, Antarctica 
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下载免费PDF全文 A study has been done on the comparison of nesting and feeding behavior, population variances as well as breeding success between two populations of south polar skua (Catharacta maccormicki) from near Great Wall station on Fildes Peninsula and near Zhongshan station in Eastern Larsemann Hills, Antarctica. There are evident differences in their population ecology. The foraging habit is much related to regional ecosystem and food resources near their territorial area. Dependence on human food waste influences skua's diet,which considerably affects their behavior even population variation in both areas. The skuas in Zhongshan Station,could shorten and/or regulate the timing for their egg laying and hatching, and take precedence of one chick brooding, for keeping their breeding success, and subsequent species continuation. 相似文献
9.
泰山景观人为干扰的程度及其影响分析 总被引：1，自引：0，他引：1
利用1986年和2001年两期TM影像,在GIS支持下,采用人为影响程度的比重和景观指数等多指标比重分析法以及人为影响类型极性分析法,对泰山景观的人为影响程度和景观结构变化作用方向进行定量描述。结果表明,人为影响类型极性分析法可以较理想地定量描述景观结构变化作用的方向和程度。在泰山风观区,景观人为综合极性影响可以划分为5个大类,影响程度可以划分为3个级别。15a来人为综合影响为正极性作用方向,其中Ⅱ级中度影响区影响系数最小,是泰山生态安全决策必须首先重视的区域。 相似文献
10.
A pockmark field has been encountered in the northwestern Barents Sea, SO km southeast of Hopen island. High resolution seismic records and side scan sonographs show that the features are small (10–20 m diameter), shallow (<1 m deep) structures that may cover up to 25% of the sea floor in local areas. Pockmark existence seem to be dependent on the presence of soft, Holocene mud. In more firm sea-floor they seem to concentrate in the partly infilled troughs of iceberg plough marks. The pockmark distribution, characteristics of the underlying sedimentary bedrock and thin cover of glacigenic sediments in the area, indicate they are formed by ascending gas from a deeper, probably petrogenic source. It is inferred that pockmarks may be found in larger parts of the Barents Sea. 相似文献
11.
JOHN-PEDER DENSTAD TORE AUNAAS JAN FREDRIK BORSETH ARNE VOLLAN AARSET KARL ERIK ZACHARIASSEN 《Polar research》1987,5(2):171-174
The occurrence of macromolecular antifreeze agents (so-called Thermal Hysteresis Factors) in blood plasma of fishes from Spitsbergen waters was investigated in August 1983, October 1984, and January 1986.
Thermal hysteresis was found in the plasma of three species of Spitsbergen fishes: shorthorn sculpin (Myoxocephalus scorpius) , polar cod (Boreogadus saida) , and sea snail (Liparis liparis) . This is the first time thermal hysteresis is reported from the sea snail. Seasonal changes in the amount of thermal hysteresis were observed in blood plasma of the shorthorn sculpin and the sea snail.
With the exception of the polar cod, blood plasma of deep water fishes displays no thermal hysteresis. The reason for this is probably that the polar cod also occurs in shallow ice laden sea water, where an'antifreeze'would be needed to protect against inoculative freezing.
No thermal hysteresis was observed in blood plasma of the saithe (Pollachius virens) , despite the fact that the saithe was observed swimming in ice laden sea water at a temperature of -1 to – 1.5°C under natural conditions, and was rapidly killed when it came into contact with ice in the laboratory. It is not known how the saithe survives in ice laden water under natural conditions. 相似文献
Thermal hysteresis was found in the plasma of three species of Spitsbergen fishes: shorthorn sculpin (Myoxocephalus scorpius) , polar cod (Boreogadus saida) , and sea snail (Liparis liparis) . This is the first time thermal hysteresis is reported from the sea snail. Seasonal changes in the amount of thermal hysteresis were observed in blood plasma of the shorthorn sculpin and the sea snail.
With the exception of the polar cod, blood plasma of deep water fishes displays no thermal hysteresis. The reason for this is probably that the polar cod also occurs in shallow ice laden sea water, where an'antifreeze'would be needed to protect against inoculative freezing.
No thermal hysteresis was observed in blood plasma of the saithe (Pollachius virens) , despite the fact that the saithe was observed swimming in ice laden sea water at a temperature of -1 to – 1.5°C under natural conditions, and was rapidly killed when it came into contact with ice in the laboratory. It is not known how the saithe survives in ice laden water under natural conditions. 相似文献
12.
极区位于高纬度地区,极区航海图投影采用墨卡托投影时,图上极区附近变形较大,在极点处变形达到无穷大;采用极球面投影时,图上恒向线不是直线;心射切面投影不是正形投影,不能直接在图上量取方位和距离;兰伯特正形投影图上,经度是由角度表示,而不是真的经度;采用横轴墨卡托投影时,几乎所有的经线以及纬线在图上为曲线。以上常用的海图投影不利于船舶在极区安全航行,也不利于航海人员进行海图作业。针对此问题,将构建的伪经纬线网与经纬线网进行转换,通过Matlab得到基于伪经纬线网的横轴墨卡托投影图,此图具有类似于墨卡托海图的特点,图上极区变形失真小,图上伪经纬线的特点可方便极区海图作业。 相似文献
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应用一维K闭合OSUPBL模式和ARCSCM极地柱模式,采用SHEBA观测资料和ECM- WF的输出结果作为模式的初始场和外强迫场,对SHEBA试验所在地(75°N,150°W)单点的北极大气边界层特征,进行了初步的模拟并与SHEBA资料进行对比分析。研究表明,这两个模式都具有较好地模拟单点北极大气边界层特征的能力。OSUPBL模式在垂直高度上的高分辨率,使其能够更好地反映大气边界层内部的细微变化特征。ARCSCM模式中考虑了比较多的物理过程,且需要提供比较完整的初始场、边界条件和侧向强迫,并每小时更新,模拟结果更符合实际情况。对模式的不足和下一步的研究也进行了讨论。 相似文献
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Liss M. Andreassen 《Geografiska Annaler: Series A, Physical Geography》1999,81(4):467-476
Storbreen glacier is situated in the western part of Jotunheimen, a mountain area in central southern Norway. Annual mass balance data have been recorded since 1949. In addition, detailed topographical maps at the scale 1:10,000 exist from the years 1940, 1951, 1968, 1984 and 1997. In this paper, volume change calculated from maps is compared with annual mass balance data. The volume change was in reasonable agreement with the measured cumulative mass balance for the periods 1940–1951 and 1968–1984; however, for the periods 1951–1968 and 1984–1997, the mass balance measurements showed larger negative values than obtained from map comparisons. One obvious reason for this is the inaccuracy of the contour lines in the upper areas of the glacier on maps from 1940 and 1951. Other factors influencing the result are tested, and also suggestions are given for improving the techniques for mapping glacier volume changes. 相似文献
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J. C. Archer G. T. Murauskas F. M. Shelley P. J. Taylor E. R. White 《The Professional geographer》1985,37(3):279-287
County scale cartographic analysis of Ronald Reagan's reelection landslide of 1984 shows the geographical core of his electoral strength to be in the Interior West, non-ethnic areas of the South, and suburbs across the nation. Examination of spatio-temporal variations using factor analysis at a state scale shows this to be a continuation and reinforcement of recent electoral-geographical cleavages. T-mode factor analysis traces the emergence of a contemporary Conservative Normal Vote during the past several presidential elections and the manifestation of this cleavage in the election of 1984. 相似文献
19.
Food samples from 102 seabirds from eight species (fulmar Fulmarus glacialis , common eider Somateria mollissima , glaucous gull Larus hyperboreus , kittiwake Rissa tridaayla , arctic tern Sterna paradisaea , Briinnich's guillemot Uria lorn via , black guillemot Cepphus grylle , little auk Alle alle) were collected during the period August 1991–1993 in the southern part of the Frans Josef Land archipelago, 80°N, 53°E. The pelagic amphipod Parathemisto libellula and polar cod Boreogadus saida were the two most commonly taken food items (frequency of occurrence over 50% and weight contribution more than 70%). Ice-associated crustaceans contributed to some 10% of the weight in the samples. In general, the food composition was very similar to that reported from Svalbard. However, birds from Frans Josef Land fed on a lower diversity of prey compared to Svalbard populations. 相似文献