The RAN Australian Hydrographic Service conducted hydrographic survey HI242 at Macquarie Island in November and December 1996. The main survey areas were Buckles Bay and Hasselborough Bay. Survey lines were also followed from Elliott Reef down the west coast to Langdon Bay and down the east coast to Buckles Bay. The survey dataset, which includes metadata, was provided to the Australian Antarctic Data Centre by the Australian Hydrographic Office and is available for download from a Related URL in this metadata record. The survey was lead by LT M.A.R.Matthews. The data are not suitable for navigation.

The AADC (Australian Antarctic Data Centre) is in the process of converting all internally held spatial datasets to the ITRF2000 horizontal datum. This consolidated dataset consists of surveys HI623_alatB_gg, HI625_alatB_GG, HI632_alat_B_gg, HI632_alat_C_gg, LADSII_MMI20756_HSDB_T0001_SD_100029052_op, LADSII_MMI20756_HSDB_T0001_SD_100029053_op, LADSII_MMI20756_HSDB_T0001_SD_100029054_op converted to ITRF2000 horizontal datum with Z conversion values for multiple height datums. The data was provided to the AAD by Paul Digney of Jacobs consulting in March 2021. Included survey datasets: • HI623_alatB_gg • HI625_alatB_GG • HI632_alat_B_gg • HI632_alat_C_gg • LADSII_MMI20756_HSDB_T0001_SD_100029052_op • LADSII_MMI20756_HSDB_T0001_SD_100029053_op • LADSII_MMI20756_HSDB_T0001_SD_100029054_op All data are in horizontal datum ITRF2000 and have been combined into a single ESRI geodatabase feature class titled AHS_Surveys_Macca_ITRF2000. Attribute data shows quality information, conversion factors (shift in metres) for multiple datums and the MSL orthometric height: Column Name Alias Meaning Easting Easting Easting ITRF2000 Northing Northing Northing ITRF2000 LAT_to_GRS LAT_to_GRS LAT (Chart Datum) to GSR80 LAT_to_Mac LAT_to_Mac LAT to Macca MSL Z_To_GRS80 Z_To_GRS80 Height to the Ellipsoid Z_To_Macca Z_To_Macca Local MSL orthometric height Vertical_U Vertical_U How good is the Vertical Position Horizontal Horizontal How good is the Horizontal Position Uncertaint Uncertaint Uncertainty Comments Depth_Comm Depth_Comments Vertical uncertainty ranges from 0.5 to 1.2 m and horizontal uncertainty ranges from 2 to 5.5 m. Null values indicate unknown uncertainty. See the attached document ‘Metadata_Record_Macqaurie Island Final.xlsx’ for further details.

The RAN Australian Hydrographic Service conducted hydrographic survey HI290 at Heard Island, February to March 1997. The survey dataset, which includes the Report of Survey, was provided to the Australian Antarctic Data Centre by the Australian Hydrographic Office and is available for download from a Related URL in this metadata record. The survey was lead by LT R.D.Bowden. The spatial extent given in this metadata record is that of Heard Island as the spatial extent of the survey is unknown to the Australian Antarctic Data Centre. The data are not suitable for navigation.

This dataset contains bathymetry (water depth), ship's heading, ship's speed and position data collected during the Nella Dan Voyage 4 1987-88. This was the Nella Dan's final voyage. Some marine science was carried out en route to Macquarie Island from Hobart. Data are available online from the Australian Antarctic Division Data Centre web page (see Related URL below). For further information, see the Marine Science Support Voyage Report at the Related URL below.

Metadata record for data from ASAC Project 2315 See the link below for public details on this project. ---- Public Summary from Project ---- Project title: EFFECTS OF THE MODULATION OF THE SURFACE SHEAR STRESS BY THE WAVE FIELD IN A MODEL OF THE SOUTHERN OCEAN This project will investigate the sensitivity of currents and tracer properties in a non-eddy-resolving ocean general circulation model to a formulation of the surface shear stress which takes account of surface air and water velocities induced by the ocean wave field. These velocities will be computed accurately from archived model wave fields and also parameterised from wind and current velocities. From the abstract of the reference paper: We present a basic analysis of the propagation of deep-water waves on curved trajectories. The key feature is that the amplitude of the wave varies transversely, and may in the generation of a short-crested of high amplitude. The properties of there waves are explored, and it is suggested that they are a model for extreme waves, which may violate the conditions under which the classical distribution of wave heights has been derived. In their full development, they are manifested a generic rouge waves. From the 2002/2003 season: The aim of this project was to investigate mode water formation south of Australia in an ocean general circulation model (OGCM). The grant monies were used to employ a numerical modeller (Dr Harun Rashid) who became familiar with the curvilinear grid version of the modular ocean model No. 1 (MOM1) model developed by Ross Murray, and then applied the model with high resolution (0.6 x 0.4 degree) in the region south-west of Tasmania, where recent observations obtained on Franklin cruise (Fr9801) to the west of the SR3 section, indicated that mode water was being formed. The model was found to be inadequate to the task of simulating the formation region, as also were the OCCAM simulations, which have been downloaded and compared with the MOM1 simulations. The reason for this negative conclusion was sought during the course of the project, and it was determined that in the OGCMs: (a) the westward advection south of Tasmania was too strong, and (b) the coefficients of lateral diffusion at deeper levels in the water column were too large. The cruise data, which were investigated by Paul Barker as part of his Ph.D. thesis, indicated that the region of water mass formation south-west of Tasmania, occurs over the depth range of the mode water and the intermediate water and through to the upper circumpolar deep water (300 - 1500 m). It was deduced that the formation mechanism involves the mixing of two source waters, one from the Tasman Sea, the other from the Southern Ocean, which combine to form Tasmanian Subantarctic Mode Water (TSAMW), Tasmanian Intermediate Water (TIW), and probably Tasmanian Upper Circumpolar Deep Water (TUCDW). The dynamical reason for the location of the water mass formation appears to be the existence of a saddlepoint in the streamflow (at which the mean horizontal velocity is zero) over the depth range (300 - 1500m), due to the gyral circulation of the South Australian Basin to the west and the retroflection of the Tasman Outflow to the east. In order to represent this physics, it is very important to simulate correctly the advection at each level in the water column This is not done by the OGCMs, but in the course of the project, the importance of advection on the position of the saddlepoint was demonstrated in a series of simulations using the transports obtained from a simple Sverdrup transport model. The modelled fields were then used to advect temperature and salinity at each level with lateral diffusion coefficients adjusted for the best match with the observed property fields. These 'best fit' lateral diffusion coefficients in the deeper levels were found to be much smaller than those used in the OGCMs. The mechanism outlined above is distinct from that in earlier work in which mode water formation was interpreted using Ekman rather then gyral dynamics, without attention being given to the deeper levels. A simple balance shows that the gyral current is of similar magnitude to the Ekman current in the surface layer, and below the surface layer the Ekman current is absent. Recently (December 2003) Ross Murray has indicated that the problem addressed in this 2002-2003 grant can be revisited, using a 20 year simulation he is obtaining with TPAC NCEP II forcing on a resolution of 1/8 degree. It is our intention to work with Ross in February 2004 to see if the problems detailed above can be overcome, so that the ocean physics in this important water mass formation region can be simulated.

This consolidated dataset consists of Australian Hydrographic Service (AHS) surveys HI621C, 5135 (Terrestrial), HI364, HI514, and HI607 converted to International Terrestrial Reference Frame 2000 (ITRF2000) horizontal datum with Z conversion values for multiple height datums. The data was provided to the AAD by Paul Digney of Jacobs consulting in February 2021. Included survey datasets: • HI621C_MAWSON_merged.shp • HI621C_MAWSON_merged.shp • Terrestrial_Data_5135 • HI364_HSDB_T0001_SD_100035029_op_soundings • QC_HI 514 HDCS_FDD_appraised (Mawson Approches) • HI607.Shp All data are in horizontal datum ITRF2000 and have been combined into a single ESRI geodatabase feature class titled AHS_Surveys_Mawson_ITRF2000. Attribute data shows quality information, conversion factors (shift in metres) for multiple datums and the MSL orthometric height: Column Name, Alias, Meaning Easting, Easting, Easting ITRF2000 Northing, Northing, Northing ITRF2000 CD_To_GRS8, CD_To_GRS80, LAT (Chart Datum) to the Ellipsoid LAT_to_GRS80, LAT_to_GRS80, LAT (Chart Datum) to GSR80 LAT_to_MSL_Mawson, LAT_to_MSL_Mawson, LAT to Mawson MSL Z_To_GRS80, Z_To_GRS80, Height to the Ellipsoid Z_To_MSL_Mawson, Z_To_MSL_Mawson, Local MSL orthometric height Vertical_U, Vertical_Uncertainty, How good is the Vertical Position Horizontal, Horizontal Uncertainty, How good is the Horizontal Position Uncertaint, Uncertainty Comments, Depth_Comm, Depth_Comments, Vertical uncertainty ranges from 0.05 to 0.64 m and horizontal uncertainty ranges from 0.05 to 1.0 m See the attached document ‘Metadata_Record_Mawson Final REV2.xlsx’ for further details.

The composition, size and abundance of phytoplankton and microzooplankton were measured across a transect from Prydz Bay to Australia during late March 1987. Phytoplankton populations were low, with concentrations of chlorophyll a ranging from 0.08 to 0.22 mg.m-3. Small cells predominated numerically; nanoplankton consistently represented 55 to 68% of the total cell number while picoplankton represented 27 to 44%. Microplankton never represented more than 3% of cells by number, but constituted 57 to 93% of the total cell volume, and accounted for most of the latitudinal variation in total volume. Small flagellates, not identifiable by light microscopy, were the most numerous cells encountered across the transect, with a five-fold increase in abundance at 47S. Numbers of diatoms (most less than 20 microns in size) increased markedly south of the Antarctic Convergence, with a strong correlation to the concentration of silica. Dinoflagellate numbers were relatively constant across the transect, although somewhat higher north of 50S. Those less than 20 microns in size were most numerous and accounted for most of the numerical variation. HPLC analysis of chlorophyll and carotenoid pigments showed a peak of peridinin which coincided with the flagellate peak at 47S, but not with observed dinoflagellates, suggesting that the flagellate peak included unrecognized dinoflagellates. Chlorophyll b and prasinoxanthin were also associated, suggesting a significant contribution by prasinophytes. Almost no cyanobacteria were observed south of the convergence, although very large numbers, which correlated with the abundance of zeaxanthin, were encountered to the north. Numbers of ciliates and tintinnids were quite variable although they followed each other closely. Numbers of both were low in the region of the Antarctic Convergence.

In January 2005 a multi-parametric international experiment was conducted that encompassed both Deception Island and its surrounding waters. This experiment used as main platforms the Spanish Oceanographic vessel 'Hesperides', the Spanish Scientific Antarctic base 'Gabriel de Castilla' at Deception Island and four temporary camps deployed on the volcanic island. This experiment allowed us to record active seismic signals on a large network of seismic stations that were deployed both on land and on the seafloor. In addition other geophysical data were acquired, such as: bathymetric high precision multi-beam data, and gravimetric and magnetic profiles. The gravimeter BELL AEROSPACE-TEXTRON BGM-3 (at the present Lockheed Martin Federal Systems) is an acquisition system that can be used both in aerial and marine vehicles. The system has a sensor mounted in a gyro-stabilized platform. This system is composed of a gravimeter sensor, the stabilized platform and an acquisition system. Raw data are recorded and processed in a computer HP-486/50 using the own BGM software providing two types of data, raw and previously analyzed data. Acquired raw data are presented in the following format: $PRAWGRV, Day, Hour, Flag, Mean Value,. However, the analyzed data are transformed into: $PHESGRV, Day, Hour, Flag, Mean Value, Value GRS67, Eotvos Correction, sinv, sinv. Potential 'flag' values associated to the sensor status are: 0: normal, 2: error, 5: starting.

This is a parent record for data collected from AAS project 4102. Project 4102 also follows on from ASAC project 2683, "Passive acoustic monitoring of antarctic marine mammals" (see the related metadata record at the provided URL). Public Summary: Half a century ago the Antarctic blue whale was perilously close to extinction. Over 350,000 were killed before the remaining few were fully protected. A decade ago this elusive and poorly understood species was estimated to be less than 5% of its pre-whaling abundance. This multi-national, circumpolar project will develop and apply powerful new techniques to survey these rare whales and gain an insight into their recovery and ecology. The project is the flagship of the Southern Ocean Research Partnership - an International Whaling Commission endorsed collaborative program.

We collected surface seawater samples using trace clean 1L Nalgene bottles on the end of a long bamboo pole. We will analyse these samples for trace elements. Iron is the element of highest interest to our group. We will determine dissolved iron and total dissolvable iron concentrations. Samples collected from 7 sites: Sites 1, 2, 3, 4 were a transect perpendicular to the edge of the iceberg to try and determine if there is a iron concentration gradient relative to the iceberg. Sites 4, 5, 6 were along the edge of the iceberg to determine if there is any spatial variability along the iceberg edge. Site 7 was away from the iceberg to determine what the iron concentration is in the surrounding waters not influenced by the iceberg.