This data set contains depth sounding data (water depths) for Ellis Fjord, one of the fjords of the Vestfold Hills. The data were collected between 1994 and 1999. See the links in the related links section for copies of maps (PDF and TIFF) of Ellis Fjord soundings, sounding transects and bathymetric contours. Map 15623: Ellis Fjord, Vestfold Hills - Depth Soundings Map 15624: Ellis Fjord, Vestfold Hills - Sounding transects Map 15625: Ellis Fjord, Vestfold Hills - Sounding transects overlaying topography Map 15626: Ellis Fjord, Vestfold Hills - Transect coordinates and ground control Map 15627: Ellis Fjord, Vestfold Hills - Bathymetric Contours

This GIS dataset is the result of the interpolation of bathymetry from depth measurements made in Long and Tryne Fjords in the Vestfold Hills, Antarctica (see Entry: VH_bathy_99). The Topogrid command within the ArcInfo GIS software, version 8.0.2, was used to do the interpolation. 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. See related URLs for a map showing the interpolated bathymetry.

From the abstract of one of the papers: Three new zooplankton nets have been designed to enable improved collection of zooplankters from ice-covered waters. These nets also enable quantitative sampling of species not adequately sampled by other methods. The first net is a vertical tow net which can be folded like an umbrella to pass through a small ice hole (10 cm). This 'Umbrella Net' takes an integrated sample of zooplankton from all sample depths. The second net is a collapsible free-fall net designed to collect mobile zooplankters capable of avoiding towed nets. This was the only net used which was capable of collecting all furcilia stages of Euphausia crystallorophias from Ellis Fjord, Vestfold Hills, Antarctica. The third net is a diver-operated push net designed to collect zooplankters in the top 15 cm of the under-ice column. Because of the high standing crop of pytoplankton at and near the under-ice surface at particular times of the year, some species of zooplankton tend to congregate there. These species, particularly Paralabidocera antarctica, were collected in great abundance using the push net, but were rare in samples collected by other methods. The fields in this dataset are: species species density site sample

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

---- Public Summary from Project ---- The lakes and fjords of the Vestfold Hills region of Antarctica provide unique ecosystems for studying environmental changes in Antarctica over the past 8000 years. Studies of the changes in organic matter composition in sediment cores provide information how the microbial and plankton communities have changed over time in response to varying chemical and physical conditions. Our study will provide new information about how the cycles of the biologically-important elements carbon and sulfur are linked and why some sediments can preserve large amounts of organic carbon. This information will be useful for studies of palaeoclimate and will also provide valuable insights into the processes that produce petroleum source rocks. From the abstracts of the referenced papers: Preserved ribosomal DNA of planktonic phototrophic algae was recovered from Holocene anoxic sediments of Ace Lake (Antarctica), and the ancient community members were identified based on comparative sequence analysis. The similar concentration profiles of DNA of haptophytes and their traditional lipid biomarkers (alkenones and alkenoates) revealed that fossil rDNA also served as quantitative biomarkers in this environment. The DNA data clearly revealed the presence of six novel phylotypes related to known alkenone and alkenoate-biosynthesising haptophytes with Isochrysis galbana UIO 102 as their closest relative. The relative abundance of these phylotypes changed as the lake chemistry, particularly salinity, evolved over time. Changes in the alkenone distributions reflect these population changes rather than a physiological response to salinity by a single halophyte. Using this novel palaeo-ecological approach of combining data from lipid biomarkers and preserved DNA, we showed that the post-glacial development of Ace Lake from freshwater basin to marine inlet and the present-day lacustrine saline system caused major qualitative and quantitative changes in the biodiversity of the planktonic populations over time. Post-glacial Ace Lake (Vestfold Hills, Antarctica), which was initially a freshwater lake and then an open marine system, is currently a meromictic basin with anoxic, sulfidic and methane-saturated bottom waters. Lipid and 16S ribosomal RNA gene stratigraphy of up to 10,400-year-old sediment core samples from the lake revealed that these environmentally induced chemical and physical changes caused clear shifts in the species composition of archaea and aerobic methanotrophic bacteria. The combined presence of lipids specific for methanogenic archaea and molecular remains of aerobic methanotrophic bacteria (13C-depleted delta8(14)-sterols and 16S rRNA genes) revealed that an active methane cycle occurred in Ace Lake during the last 3000 calendar years and that the extant methanotrophs were most likely introduced when it became a marine inlet (9400 y BP); rDNA sequences showed 100% sequence similarity with Methanosarcinales species from freshwater environments and were the source of sn-2- and sn3-hydroxyarchaeols. Archaeal phylotypes related to uncultivated Archaea associated with various marine environments were recovered from the present-day anoxic water column and sediments deposited during the meromictic and marine period.