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  • Water depth measurements were taken in Long Fjord during early winter in 2007. The measurements were collected by Graham Cook, station leader at Davis Station in the Australian Antarctic Territory. The measurements were made by dropping a weighted line off the back of a quad bike, after drilling a hole through the sea ice. Measurements were made approximately every 100 metres. The download file contains a csv spreadsheet which lists each waypoint, plus the corresponding water depth and any comments. The text file contains the waypoint information collected by the Garmin GPS unit. Data in the text file are comma separated and are interpreted as follows: WP,D,001 (waypoint) , -68.51341000, 78.06903000,(Latitude and Longitude) 05/25/2007, 10:25:35, (Date and time Downloaded to Computer) 24-MAY-07 11:40:42 (Date and time of reading). Time is in local time. Vegetation was found on the weight that we used when we first started at the seaward end of the Fjord and then again in shallow water between Brookes Hut and a small island 800 or 900 metres out from Brookes. The weight is quite smooth and does not pick up a lot. The reference given below provides some further information about previously collected bathymetry data in Long Fjord. Furthermore, also see the metadata records: 'Bathymetric data of Long and Tryne Fjords at Vestfold Hills, Antarctica, collected in December 1999 [VH_bathy_99]' 'Interpolated bathymetry of Long and Tryne Fjords, Vestfold Hills, Antarctica [long_tryne_bathy]' The fields in this dataset are: Waypoint Latitude Longitude Water Depth Date Time

  • This dataset contains 102 depth measurements of the water column in Long and Tryne fjords, which are in the northern Vestfold Hills, Prydz Bay, Antarctica. Sea ice thickness and snow thickness were recorded simultaneously. The motivation for this project has been to yield a description of the pupping and moulting habitat of Weddell seals. This information will assist the interpretation of 25+ years of data on seal distribution within that area. Our data were collected between 7th and 13th December 1999. The measurement sites were chosen according to geographical features; their exact location was determined by GPS with an accuracy of about 25m. At each site a 5cm diameter hole was drilled through the sea ice and a weighted measurement tape was lowered through the ice-hole to the bottom. Water depths were measured to the nearest centimetre; ice and snow thicknesses were measured to the nearest millimetre. A minimum depth of less than 3m was found in a narrow channel between small islands immediately west of Shirokaya Bay. The maximum depth of the water column was 222m in the middle basin of Long Fjord. The tidal range for the measured days was less than 0.5m, with tidal corrections applied to the raw data. Water samples were taken in Breid Basin and the middle basin of Long Fjord. These and water samples taken in Snezhnyy Bay [pers. comm. J. Laybourn-Parry, 1999] show aerobic and relatively fresh water for all upper basins. This indicates that even the far basins of both fjords are well mixed despite the drainage of large volumes meltwater from the Antarctic plateau into the fjords. See related URL for data and a spatial summary of the data. See Entry: long_tryne_bathy for an interpolation of bathymetry made using the Topogrid command within the ArcInfo GIS software, version 8.0.2. Coastline and spot height (heights above sea level) data, extracted from the Australian Antarctic Data Centre's Vestfold Hills topographic GIS dataset (see Entry: vest_hills_gis), was also used as input data to optimise the interpolation close to the coastline. The fields in this dataset are: day weighpoint lat(dd) long(dd) ice (cm) freeboard(cm) snow(cm) depth(m)

  • This metadata record covers ASAC projects 113, 191 and 625. (ASAC_113, ASAC_191, ASAC_625). The total lipid, fatty acid, sterol and pigment composition of water column particulates collected near the Australian Antarctic Base, Davis Station, were analysed over five summer seasons (1988-93) using capillary GC, GC-MS, TLC-FID and HPLC. Polar lipids were the dominant lipid class. Maximum lipid concentrations usually occurred in samples collected in December and January and corresponded with increased algal biomass. Both lipid profiles and microscopic observations showed significant variation in algal biomass and community structure in the water column during each season and on an interannual basis. During the period of diatom blooms (predominantly Nitzschia species) the dominant sterol and fatty acid were trans-22-dehydrocholesterol and 20:5w3, accompanied by a high 16:1w7 to 16:0 ratio. Very high polyunsaturated fatty acid and total lipid concentrations were associated with diatom blooms in the area. Bacterial markers increased late in all seasons after the summer algal blooms. Long chain C30 sterols also increased during the latter half of all seasons. Fjord samples collected in the area reflected greater biomass and diversity in algal and bacterial makers than coastal sites. Signature lipids for the alga Phaeocystis pouchetii, thought to be a major alga in Antarctic waters, were identified in field samples over the five summer seasons studied. Methods Study site Davis Base is situated on the Vestfold Hills, Antarctica and incorporates numerous lakes and fjords (Fig. 1). Samples of water column particulate matter were collected during five summer seasons (1988-93), 500 meters off-shore from Magnetic Island, situated 5 km NW of Davis. Three other sampling areas were situated in the fjords of the Vestfold hills and include two sites in Ellis Fjord, one midway along Ellis Fjord and one near Ellis Fjord mouth and one sample midway along Long Fjord (Fig. 1). These fjords are protected from the marine environment, but are both marine fjords. Davis Station and Magnetic Island were used for the weekly sample sites. The mouth of Long Fjord, the mouth of Ellis Fjord, midway down Long Fjord, the deep basin in Ellis Fjord, O'Gorman Rocks and Hawker island (ocean side) were used for monthly samples. Field collection There was an initial pilot season in 1988-89, which was followed by two more detailed studies in the summers of 1989-90 and 1990-91. Four samples was also analysed from the 1991-92 and five from the 1992-93 summer seasons. During the initial pilot study at Magnetic Island in the 1988-89 summer, three water column particle samples were taken for lipid analyses. The 1989-90 and 1990-91 summer field seasons incorporated weekly sampling of the water column particulates at Magnetic Island. The phytoplankton in the fjords were studied during the summers of 1989-90 and 1990-91. The three sites that were chosen were all sampled three times in each season. Samples were also collected during the 1989-90 and 1990-91 seasons from the Magnetic Island and Fjord site s for pigment analyses. Three and five samples were collected respectively in the 1991-92 and 1992-93 seasons. Samples were also taken for microscopic analyses. For lipid analyses 30-40 liter water column particulate samples were collected at a depth of 10 m. A Seastar or INFILTREX water sampler was used in situ to filter the water through a 14.2 cm Schleicher and Schuell glass fibre filter over a three to four hour period. All filters used during sampling were preheated in a muffle furnace at 500 degrees C overnight to minimise contamination. For pigment analyses 2 to 4 litres were filtered through glass fibre filters (4.7 cm GF/F, nominal pore size 0.7 micro meters). The samples were frozen at -20 degrees C until extraction.

  • The data set includes information relevant for the study and description of sea-ice bacteria contains the following dataset subgroups and is organised by REFERENCE number. 1) Isolation data: strain designations (e.g. culture collection names are indicated for type cultures); media used for isolation and routine cultivation; temperature used for incubation; any special conditions (e.g. enrichment conditions) used for isolation; isolation site and type (e.g. sea-ice); availability of the indicated strain from the chief investigator (J. Bowman) 2) Phenotypic data: Includes morphological, physiological and biochemical tests performed. Details on how these were performed are indicated in the relevant reference. 3) Growth/temperature data: data for temperature related growth curves are given where available. Methods are indicated in the associated reference. 4) Fatty acid/chemotaxonomy data: fatty acid and other related data are given where available. Methods are indicated in the associated reference. 5) Genotypic data: data for DNA-guanosine/cytosine-content and genomic DNA:DNA hybridization are shown where available. Methods are indicated in the associated reference. 6) Phylogenetic data: data for sequences are cross-referenced to the GenBank database. In some cases, aligned sequence datasets are available in FASTA format and can be viewed in the programs BIOEDIT (www.mbio.ncsu.edu/BioEdit/bioedit.html) or CLUSTAL W (www.ebi.ac.uk/clustalw). 7) Other related published references which are useful or relevant to the dataset e.g. related sequences published subsequent to the ASAC study