bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fur seal skull from sealers' quarters at Sandy Bay, Macquarie Island, Southern Ocean
Authors: Townrow K. , Shaughnessy P. D. 
Published: October 2009

AbstractFur seals were exterminated from Macquarie Island about 20 years after discovery of the island in 1810. Their specific identity is unknown. Few fur seals were reported at the island until it was occupied by the Australian National Antarctic Research Expeditions in 1948. Fur seal numbers are now increasing. An archaeological excavation at a sealers' quarters at Sandy Bay in 1988 revealed the fragmented skull of a young Antarctic fur sealArctocephalus gazella1.1 m below the surface in a layer dated in the 1870s and 1880s. This period coincides with the recovery of fur seal populations in the South Atlantic Ocean following earlier harvesting. Elsewhere it has been argued that the Antarctic fur seal is unlikely to have been the original fur seal at Macquarie Island because few individuals of that species are ashore in winter, which is the season when the island was discovered and fur-seal harvesting began. It is concluded that the Sandy Bay skull is from a vagrant animal.
Soviet-Norwegian Historical Expedition to Zemlya Frantsa-Iosifa
Authors: Barr Susan 
Published: October 2009

AbstractIn summer 1990 a Soviet-Norwegian expedition spent three weeks travelling to and around Zemlya Frantsa-Iosifa (Franz Joseph Land). The main purpose of the expedition was to locate the remains of Fridtjof Nansen and Hjalmar Johansen's wintering quarters of 1895–96, and other historical sites at Cape Flora, Eira Harbour, Camp Ziegler, Buchta Tichaja and Teplitz Bay were also visited. The group experienced an amazing openness in this area which has been closed to visitors since 1930. The historical sites and their present condition are described.
Municipal government in Greenland
Authors: Benoit France , Martens Gunnar 
Published: October 2009

AbstractThis article describes how Greenlandic municipalities operate. A summary of the evolution of municipal government in Greenland is followed by an overview of their demography, politics, and administration. A list of jurisdictions is provided through a study of municipal expenditures, with reference to the municipality of Narsaq (Narsap kommunia). The article concludes with an examination of the perspectives of municipal government in Greenland.
The hunt for marine reptile fossils on western Ellesmere Island
Authors: Osczevski Randall J. 
Published: October 2009

AbstractAn expedition of the Canada/China Dinosaur Project collected several large marine-reptile fossils on western Ellesmere Island in the summer of 1989. They were led to the area by a 1939 report that a large fossil skeleton had been seen north of Trold Fiord by a member of a Royal Canadian Mounted Police patrol in 1926. This paper examines the events of the original discovery and an unsuccessful attempt by David Haig-Thomas to locate the fossils in 1937–38. Haig-Thomas had visited the area in 1935 as a member of the Oxford University Ellesmere Land Expedition. His party had reached a fiord variously identified as Trold Fiord or Vendomc Fiord, but a study of his probable route suggests that it was neither. This inaccurate identification misled Haig-Thomas' later search. In 1989, pieces of fossil bone from a large marine reptile were collected at a site compatible with the 1939 description.
The source and calving of ice island ARLIS-II
Authors: Jeffries Martin O. 
Published: October 2009

AbstractOn the basis of existing data on the dimensions, shape, surficial geology, and glaciological structure of ice island ARLIS-II, used in combination with aerial photographs of northernmost Ellesmere Island taken in 1950 and 1959, the source of the ice island is positively identified as the Alfred Ernest Ice Shelf. The duration of the recent drift of ‘Hobson's Choice’ ice island from the vicinity of the Alfred Ernest Ice Shelf to northern Ellef Ringnes Island, used as a model for the duration of the drift of ARLIS-II between the same points, suggests ARLIS-II broke off the ice shelf in approximately 1955.
Satellite remote sensing of polar snow and ice: present status and future directions
Authors: Massom Robert 
Published: October 2009

AbstractPolar snow and ice masses exert a profound influence on global climate and ocean circulation, and are in turn influenced by climate. Satellite remote sensing constitutes the only practical and systematic means of gaining long-term overviews of any change or variability that may be occurring in key snow and ice parameters. Current relevant satellite sensors are reviewed and future developments evaluated to determine how these may lead to improved retrievals of the key parameters. Sensors to be launched on satellite platforms planned for the end of the century and beyond include both improved versions of existing sensors (such as MODIS) and new classes of sensors (such as imaging spectrometers and laser rangers/altimeters) applied to polar remote sensing for the first time.
Ice processes and growth history on Arctic and sub-Arctic lakes using ERS-1 SAR data
Authors: Morris K. , Jeffries M. O. , Weeks W. F. 
Published: October 2009

AbstractA survey of ice growth and decay processes on a selection of shallow and deep sub-Arctic and Arctic lakes was conducted using radiometrically calibrated ERS-1 SAR images. Time series of radar backscatter data were compiled for selected sites on the lakes during the period of ice cover (September to June) for the years 1991–92 and 1992–93. A variety of lake-ice processes could be observed, and significant changes in backscatter occurred from the time of initial ice formation in autumn until the onset of the spring thaw. Backscatter also varied according to the location and depth of the lakes. The spatial and temporal changes in backscatter were most constant and predictable at the shallow lakes on the North Slope of Alaska. As a consequence, they represent the most promising sites for long-term monitoring and the detection of changes related to global warming and its effects on the polar regions.
Comparative evaluation of ALMAZ, ERS-1, JERS-1, and Landsat-TM for discriminating wet tundra habitats
Authors: Belchansky Gennady I. , Ovchinnikov Gregory K. , Douglas David C. 
Published: October 2009

AbstractSystematic image-classification methods were applied to ALMAZ, ERS-1, and JERS-1 synthetic aperture radar (SAR) and Landsat-TM multispectral satellite images to evaluate the relative information content of the satellite data for discriminating wet tundra habitats in northern Alaska. Results suggest that SAR data can be used to concurrently detect a maximum of four or five landcover classes using the methods of this study. Combining two or more SAR images from different satellites improved the detection of some classes, particularly water bodies. Combining full-resolution SAR data with Landsat-TM did not improve the detection capabilities of Landsat-TM alone. Further research is needed to assess other image-classification and SAR data processing methods.
NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska
Authors: Walker D.A. , Auerbach N.A. , Shippert M.M. 
Published: October 2009

AbstractThe patterns of the normalized difference vegetation index (NDVI) on three glacial surfaces of different ages in the vicinity of Toolik Lake, Alaska, were examined. NDVI was derived from SPOT multispectral digital data, and the images were stratified according to boundaries on glacial geology and vegetation maps. Ground-level measurements of NDVI from common vegetation types were also collected, using a portable spectrometer. Late Pleistocene glacial surfaces have lower image-NDVI than older Middle Pleistocene surfaces, and the mean NDVI is correlated with approximate time since deglaciation. The trends are related to differences in NDVI associated with vegetation growing on mineral vs peaty substrates. Nonacidic mineral substrates are more common on the younger landscapes, and acidic peaty soils are more common on the older surfaces. The field-NDVIs of acidic dry, moist, and wet tundra are consistently higher than those of corresponding nonacidic tundra types. These same trends are seen when the SPOT NDVI image is stratified according to vegetation boundaries appearing on two detailed vegetation maps in the region. Above-ground biomass of moist and wet acidic tundra is significantly greater than corresponding nonacidic types. Vegetation species composition was examined along two transects on the oldest and youngest glacial surfaces. Shrub cover is the most important factor affecting the spectral signatures and biomass. Older surfaces have greater cover of shrub-rich tussock tundra and shrub-filled water tracks, and the younger surfaces have more dry, well-drained sites with low biomass and relatively barren nonsorted circles and stripes. These trends are related to paludification and modification of the terrain by geomorphic and geochemical processes. Similar patterns of spectral reflectance have been noted in association with a variety of large-scale natural disturbances in northern Alaska. However, extrapolation of these results to much broader regions of the circumpolar Arctic will require the use of sensors covering larger areas, such as the AVHRR aboard the NOAA satellites.
Monitoring, classification, and characterization of interior Alaska forests using AIRSAR and ERS-1 SAR
Authors: Williams C.L. , McDonald K. , Rignot E. , Viereck L.A. , Way J.B. , Zimmermann R. 
Published: October 2009

AbstractAt the Bonanza Creek Experimental Forest (BCEF), past ecological research has been directed at forest successional processes on the floodplain of the Tanana River and adjacent uplands. Research at the Bonanza Creek site continues on the mosaic of forests, shrublands, and wetlands in a wide variety of successional stages on the Tanana floodplain. This paper reviews research since 1988 into the capabilities of Synthetic Aperture Radar (SAR) for monitoring, classification, and characterization of these forests using radar remote sensing and modelling techniques. Classifications of successional stages, obtained by use of different classifiers on multi-frequency and multi-polarimetric AIRSAR data, are contrasted; these classifications have been used to predict classification accuracies obtained with ERS-1 data, and to estimate the utility of an ERS-1 and RADARSAT combination for classification. Forest classifications, used in combination with ground-truth data for more than 50 forest stands, are used to summarize the distribution of biomass on the landscape. This will allow projections of future biomass. Monitoring of forest phenology, seasonality of flooding, and freeze–thaw transitions is ongoing. Also, direct monitoring of dominant tree species is demonstrating diurnal variation and interrelationships among environmental, physiological, and backscatter measurements.
Relating CO2 fluxes to spectral vegetation indices in tundra landscapes: importance of footprint definition
Authors: Hope A.S. , Fleming J.B. , Vourlitis G. , Stow D.A. , Oechel W.C. , Hack T. 
Published: October 2009

AbstractCarbon flux measurements made at an elevated point are associated with an effective upwind area or ‘footprint.’ Since Arctic tundra landscapes can exhibit substantial heterogeneity within the footprint of an eddy correlation tower, it may be necessary to determine the relative point source contributions to the observed flux if landscape properties are to be related to the flux. This study evaluates the potential importance of representing footprint source contributions in relationships that are developed between tower observations of net ecosystem exchange of carbon dioxide (NEE) and a remotely sensed spectral vegetation index. Satellite data collected over the foothills region of the North Slope of Alaska are used to determine spatial patterns of a spectral vegetation index in the calculated footprints of 30 randomly selected tower locations. A previously developed relationship between NEE and the vegetation index is used to calculate NEE at each tower location using two techniques, one that explicitly considers the footprint pattern of relative contributions to tower fluxes and another that ignores these patterns. The results indicate that if carbon fluxes measured at a tower are to be related to remotely sensed spectral vegetation indices, then it is necessary to consider the relative flux contributions from within the tower footprints for sites on the North Slope of Alaska.
On the possibility of remotely sensing global dimethyl sulfide sea-to-air flux
Authors: Jodwalis Clara M. , Benner Richard L. 
Published: October 2009

AbstractBiogenic emissions of sulfur from the ocean surface are believed to be a significant contribution to the atmospheric aerosol burden, thus playing a significant role in climate. The possibility exists for using remotely sensed data to locate sources, map distributions, and estimate global-scale fluxes of marine sulfur flux. By definition, estimates of surface trace-gas flux from satellites are indirect. Empirical algorithms must be derived using direct surface flux measurements. This technology does not currently exist, and may be many years from coming to fruition. This paper discusses the possibilities of developing a satellite-based dimethyl sulphide (DMS) flux capability and describes a new technique that can be used to develop the necessary empirical relationships. It demonstrates the feasibility of using a sulfur chemiluminescence detector (SCD) for measuring surface sulfur-gas flux directly from the ground. It also estimates ocean surface sulfur-gas flux using two related, indirect methods, known as the variance method and the inertial dissipation method. These methods can be used in the Arctic, where the ocean-to-atmosphere flux may be a significant fraction of global biogenic sulfur emissions.
Measurements of calcium and phosphorus concentrations in the neonatal dentine of Weddell and crabeater seals using energy-dispersive x-ray analysis
Authors: Cruwys E. , Robinson K. , Boyd I.L. 
Published: October 2009

AbstractConcentrations of calcium and phosphorus were measured in the neonatal dentine of 11 crabeater and 11 Weddell seal postcanine teeth with an energy-dispersive x-ray analyser. The extent of variation in elemental concentrations in different parts of the tooth, differences between species and individuals, and whether variation in elemental concentrations can provide information about dentine deposition mechanisms were assessed. No consistent patterns in elemental deposition in different parts of the tooth were found, but there were differences in concentrations between and within species. Post-natal dentine is composed of layers that appear alternately bright and dark in backscattered electron images. The elemental composition of neonatal dentine was closer to the dark bands than to those that appeared bright. It is suggested that the composition of neonatal dentine is more similar to the dark than the bright layers of dentine because of nutritional stresses that were occurring during mineral deposition.
Antarctica and the modern geographical imagination (1918–1960)
Authors: Dodds Klaus J. 
Published: October 2009

AbstractThis paper examines how different technologies of exploration and mapping transformed human understanding of the Antarctic in the period 1918–1960. In the aftermath of the ‘heroic’ expeditions, European and American governments began to invest considerable monies in support of national expeditions for the purpose of claiming and mapping the polar continent. The collection of practical geographical information during the inter-war period was overtaken by the advent of polar aviation and aerial mapping in the 1930s. The aeroplane and the aerial camera played key parts in expanding stores of knowledge about the continent and altering perceptions of place. Finally, the paper considers the 1955–1958 Trans-Antarctic Expedition (TAE). This venture was significant because it was widely understood to be the final chapter in the geographical and scientific assualt on the Antarctic. The TAE was the high point of polar achievement, as a range of technologies were brought to bear on the surface of the Antarctic icesheet. Thereafter, the cultural and political significance of the polar continent changed in the face of new challenges for human exploration in the realms of outer space and the Moon.
Arctic summer sea-ice SAR signatures, melt-season characteristics, and melt-pond fractions
Authors: Jeffries M. O. , Schwartz K. , Li S. 
Published: October 2009

AbstractVariations in multiyear sea-ice backscatter from the synthetic aperture radar (SAR) aboard the ERS-1 satellite are interpreted in terms of melt-season characteristics (onset of melt in spring and of freeze-up in autumn, and the duration of the snow-decay period, the melt season, and the melt-pond season) from late winter to early autumn 1992 in two regions of the Arctic Ocean: the northeastern Beaufort Sea adjacent to the Queen Elizabeth Islands in the Canadian high Arctic and the western Beaufort Sea north of Alaska. In the northeastern Beaufort Sea, the onset of melt occurs later, and the periods of snow-cover decay and the occurrence of melt ponds are shorter than in the western Beaufort Sea. These melt-season characteristics of each area are consistent with previous observations that the northeastern Beaufort Sea has one of the most severe summer climates in the Arctic Ocean. A model, which assumes that the backscatter from multiyear floes is the sum of backscatter from bare ice and melt ponds, is used to derive the melt-pond fraction during the summer. The results show that melt-pond fractions decrease from an early-summer maximum of about 60% to a late-summer minimum around 10%. The magnitude of the melt-pond fractions and their decline during the summer is consistent with previous, more qualitative data. The SAR model, which gives melt-pond fractions with lower variability and less uncertainty than previous data, offers an improved approach to the reliable estimation of the areal extent of water on ice floes. Suggestions for further improvement of the model include accounting for the consequences of wind-speed variations, summer snowfall, and freeze/thaw cycles and their effects on melt-pond and ice-surface roughness.
Short- and long-term impacts of human disturbances on snow-free surfaces in Antarctica
Authors: Campbell I. B. , Claridge G. G. C. , Balks M. R. 
Published: October 2009

AbstractThe speed with which tracks form as a result of trampling on exposed ground surfaces in Antarctica was investigated in the McMurdo Sound and Dry Valleys regions, by a simple treading experiment. Distinct tracks formed with fewer than 20 foot passes — as measured by stone cover, surface soil exposure, and track width — and they continued to develop with increasing traffic levels. Track development was rapid and most obvious on sandy gravel soils with a pebbly desert pavement, but slower and less distinct on soils with an extensive cover of surface boulders.The persistence of human impact from ground disturbances, which occurred up to 30 years previously, when pits were dug during field science investigations, was assessed using a range of previously defined criteria. Recently disturbed sites, where some action had been taken to restore the site immediately after disturbance, showed the least overall impact. Impacts persisted longer at sites where no restoration had been undertaken, but the remaining impact varied with factors such as exposure to wind and the age of the land surface. These results demonstrate the fragility of Antarctic soil surfaces and the terrestrial environment, as well as the long time-scales for recovery of Antarctic ground-surface disturbances.
Scale, context, and application of traditional knowledge of the Canadian north
Authors: Duerden Frank , Kuhn Richard G. 
Published: October 2009

AbstractThere is strong contemporary interest in the application of traditional environmental knowledge (TEK) of physical environments and land-use patterns in northern Canada. This interest relates to land claims, land-use planning, cultural preservation, resource management, and environmental monitoring. The application of TEK to land and resource management is critically examined and a typology relating scale, user group, and the transformation of knowledge is developed. Of the many challenges facing the incorporation of TEK in resource-management initiatives, perhaps the greatest is the recognition of the appropriateness of scale. The conclusions reached in this paper reaffirm the notion that scale and context are key components in maintaining the validity and integrity of TEK. The primary role of TEK appears to be with providing the most valid and intelligible interpretations of local geographies and prescribing locally appropriate resource-management strategies.
The sublime yet awful grandeur: the Arctic panoramas of Elisha Kent Kane
Authors: Potter Russell A. , Wamsley Douglas W. 
Published: October 2009

AbstractIn mid-nineteenth century America, the Arctic adventures of Elisha Kent Kane were a common and central subject for the emerging mass media. Kane's exploits were retold through illustrated newspapers, magazines, and books, but his narratives found one of their widest audiences through the medium of the ‘panorama.’ Initially presented in fixed locations, these panoramas later traveled across the country, combining large moving canvasses with a variety of visual and theatrical effects. Kane's two Arctic expeditions were among the most popular subjects represented by panoramas in the period before the American Civil War. This article examines the history of the panorama as it reflected and shaped public interest in the Arctic regions, including earlier polar expeditions, and gives a detailed account of the Kane panoramas. Other optical media that represented Kane's exploits are also considered. Because of its broad audience and widespread appeal, the panorama, along with other emergent visual technologies, played a vital yet overlooked part, both in disseminating Kane's accomplishments and in elevating Kane to prominence and fame in the mid-nineteenth century.
Oriented lake-and-ridge assemblages of the Arctic coastal plains: glacial landforms modified by thermokarst and solifluction
Authors: Grosswald Mikhail G. , Hughes Terence J. , Lasca Norman P. 
Published: October 2009

AbstractOriented assemblages of parallel ridges and elongated lakes are widespread on the coastal lowlands of northeast Eurasia and Arctic North America, in particular, in Alaska, Arctic Canada, and northeast Siberia. So far, only the oriented lakes have been of much scientific interest. They are believed to be formed by thermokarst in perennially frozen ice-rich sediments, while their orientation is accounted for either by impact of modern winds blowing at right angles to long axes of the lakes (when it concerns individual lakes), or by the influence of underlying bedrock structures (in the case of longitudinal and transverse alignment of lake clusters).En masseexamination of space images suggests that oriented lake-and-ridge assemblages, not the oriented lakes alone, occur in the Arctic. Hence any theory about their formation should account for the origin and orientation of the assemblages as a whole. The existing hypotheses appear inadequate for this end, so this paper proposes that the assemblages were initially created by glacial activity, that is, by ice sheets that drumlinized and tectonized their beds, as well as by sub- and proglacial meltwater, and then they were modified by thermokarst, solifluction, and aeolian processes. This assumption opens up an avenue by which all known features of oriented landforms in the Arctic can be explained. The paper suggests that the oriented landforms in Siberia and Alaska are largely signatures of a marine Arctic ice sheet that transgressed from the north, while the Baffin Island and Mackenzie Delta forms were created by the respective sectors of the Laurentide ice sheet. The oriented features discussed belong to the last Late Glacial through the Early Holocene.