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VESTFOLD HILLS

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  • This database is a compendium of histories of known age seals (Weddell) from observations across the Southern Ocean but focussed on the Windmill Islands, Mawson and the Vestfold Hills. Although the following information pertains to Elephant Seals, it is assumed similar procedures were undertaken with the Weddell Seals between 1973 and 2006: At Macquarie Island 1000 seals were weighed per annum between 1993-2003 at birth and individually marked with two plastic flipper tags in the inter-digital webbing of their hind flippers. These tagged seals were weighed again at weaning, when length, girth, fat depth, and flipper measurements were made. Three weeks after weaning 2000 seals were permanently and individually marked by hot-iron branding. Recaptures and re-weighings of these known aged individuals were used to calculate growth and age-specific survival of the seals. Similar data were collected from elephant seals between 1950 and 1965 when seals were individually marked by hot-iron branding. Mark-recapture data from these cohorts were used to assess the demography of the declining population. Length and mass data were also collected for these cohorts and were used, for the first time, to assess the growth of individual seals without killing them. The database was held by the Australian Antarctic Data Centre, but was taken offline due to maintenance problems. A snapshot of the database was taken in June 2018 and stored in an access database. This work was completed as part of ASAC project 90.

  • This dataset contains the outdated and redundant bathymetric contour data for some of the lakes of the Vestfold Hills. Lake data for Burton Lake, Deep lake and Ellis Fjord.

  • From the referenced paper: The frigid concentration or freezing of seawater is an important natural phenomenon in the polar regions and results in the precipitation of a different sequence of salts - and thus produces brines of different composition - to that formed during isothermal evaporation under temperate conditions (about 20-25 degrees C). Seawater freezing, however, has been studied less extensively than evaporation and somewhat greater uncertainty exists over the exact nature of the compositional pathway followed. Most investigators have shown that the precipitation of mirabilite (Na2SO4 - 10 H2O) or gypsum (CaSO4 - 2 H2O), which both occur at the same seawater concentration factor (SWCF), is the critical difference between frigid and evaporative concentration, respectively, a consequence of the very different temperature dependence of the solubilities of these salts, as well as the effect of sodium chloride on these properties. This difference can be considered to represent a temperature-dependent chemical divide in the closed-basin concentration of seawater because it determines significantly the major ion composition of the brine and the salt mineral assemblage precipitated on further evolution of the system. Recently new insights into seawater freezing have been achieved through improvements in existing chemical equilibrium models. Along with the results of some associated experimental work, this has provided evidence for the formation of gypsum during freezing, contradicting the accepted Ringer-Nelson-Thompson model of frigid concentration firmly established in the 1950's and through subsequent studies, but validating an alternative model proposed by Gitterman two decades later.

  • This data set contains locations of sample sites for Ellis Fjord (1989), Organic Lake (1985) and Deep Lake (1975, 1975) in the Vestfold Hills. Unfortunately little is known as to what samples were collected. It is believed that water samples were taken at all locations, and that bottom sediment samples were taken at least at Deep Lake. When questioned in 2009, the investigating scientist was unable to remember exactly what work was done. The original maps may provide some clues.

  • The underwater and in-air recordings were used to derive a technique to classify the call types. The in-air recordings demonstrated that both males and females vocalise and often a single seal will string up to 6 call types together in a variety of orders. No 'Trills' were heard by males or females on the ice. The seals lengthened the duration of multiple-element calls when they were 'interrupted' by another calling seal. This suggests that the seals are listening for the calls of conspecifics while they themselves are calling. A pilot project indicated that almost none of the calls are completely masked by other calling seals. The recordings are being used (in association with recordings obtained in later years) to address other aspects of Weddell seal vocal communication. See the link below for public details on this project.

  • Colonisation of Lake Fletcher, a hypersaline, meromictic lake in the Vestfold Hills, Antarctica, by the calanoid copepod Drepanopus bispinosus, the cyclopoid copepod Oncea curvata and an undescribed cydippid ctenophore is discussed. In 1978, salinity direstly under the ice was 66 ppt and repeated net hauls found no zooplankton. In 1983, adults of D. bispinosus were found, and in 1984, a reproductively active population of this species. Surface water salinity in 1984 was 56 ppt. During winter 1986, surface salinity was 54 ppt and three zooplankton species (D. bispinosus, O curvata and an undescribed cydippid ctenophore) had established populations in the lake. In 1986/87, high tides caused nearby Taynaya Bay to flood into the lake, and three further species (the calanoid, Paralabidocera antarctica, and two harpacticoids, Harpacticus furcatus and Idomene sp.) were found in the lake. It appears that periodic flooding after 1978 caused a salinity decrease in the lake from 66 to 54 ppt, and this enabled some invertebrate species to maintain year-round populations, whereas others require marine incursions to re-establish summer only populations. The fields in this dataset are: Date Salinity Record Species

  • Aerial photography (Linhof) of penguin colonies was acquired over the Vestfold Hills (Eric Woehler). The penguin colonies were traced, then digitised (John Cox), and saved as DXF-files. Using the ArcView extension 'Register and Transform' (Tom Velthuis), The DXF-files were brought into a GIS and transformed to the appropriate islands.

  • From the abstract of the referenced paper: Spring phytoplankton communities in the water column of Ellis Fjord are characterised by diatoms originating from the bottom sea-ice strand community. Upon ice break-out in early summer, these are replaced by blooms of the phytoflagellates, Phaeocystis puchetii, Cryptomonas cryophila, Pyramimonas gelidicola, silicoflagellates and dinoflagellates. The narrow entrance of the fjord and the development of summer stratification is probably limiting the availability of nutrients and containing the magnitude of the small bloom (maximum 2.8 million cells per litre).

  • This database is a compendium of histories of known age seals (Weddell and Southern elephant) from observations across the Southern Ocean but focussed on Macquarie Island, Marion Island, Heard Island, Mawson and the Vestfold Hills. At Macquarie Island 1000 seals were weighed per annum between 1993-2003 at birth and individually marked with two plastic flipper tags in the inter-digital webbing of their hind flippers. These tagged seals were weighed again at weaning, when length, girth, fat depth, and flipper measurements were made. Three weeks after weaning 2000 seals were permanently and individually marked by hot-iron branding. Recaptures and re-weighings of these known aged individuals were used to calculate growth and age-specific survival of the seals. Similar data were collected from elephant seals between 1950 and 1965 when seals were individually marked by hot-iron branding. Mark-recapture data from these cohorts were used to assess the demography of the declining population. Length and mass data were also collected for these cohorts and were used, for the first time, to assess the growth of individual seals without killing them. At Marion Island all the elephant seals have been individually marked with two plastic flipper tags in their rear flippers. Recaptures of these seals were used to compare survival at Marion and Macquarie Islands. At Heard Island, seals were branded between 1949-1953. Seal length was measured in feet and inches. Recaptures of seals were made up until 1955, and growth and age-specific survival was calculated. Survival data from Heard Island were compared with concurrent data from Macquarie Island. The database was held by the Australian Antarctic Data Centre, but was taken offline due to maintenance problems. A snapshot of the database was taken in June 2018 and stored in an access database. This work was completed as part of ASAC project 90.

  • Ellis Fjord is a small, fjord-like marine embayment in the vestfold Hills, eastern Antarctica. Modern sediment input is dominated by a biogenic diatom rain, although aeolian, fluvial, ice-rafted, slumped and tidal sediments also make a minor contribution. In areas where bioturbation is significant relict glaciogenic sediments are reworked into the fine-grained diatomaceous sediments to produce poorly sorted fine sands and silts. Where the bottom waters are anoxic, sediments remain unbioturbated and have a high biogenic silica component. Three depositional and non-depositional facies can be recognised in the fjord: an area of non-deposition around the shoreline; a relict morainal facies in areas of low sedimentation and high bioturbation; and a basinal facies in the deeper areas of the fjord.