Tides are measured using a submerged pressure type gauge secured in a heavy concrete mooring in Nella Fjord in the Larsemann Hills near Zhong Shan station. Tidal records are retrieved from the gauge using an inductive loop lowered through a hole in the ice hence the gauge has been undisturbed since it was deployed. Documentation dated 2001-06-12 Zhong Shan Submerged Tide Gauge The gauge used at Zhong Shan was designed in 1991/2 by Platypus Engineering, Hobart, Tasmania. It was intended to be submerged in about 7 metres of water in a purpose made concrete mooring in the shape of a truncated pyramid. The mooring for the Zhong Shan gauge was cast in concrete at Davis and sling loaded by helicopter to Nella Fjord in the Larsemann Hills and deployed through a hole in the ice. The gauge measures pressure using a Paroscientific Digiquartz Pressure Transducer with a full scale pressure of 30 psi absolute. The accuracy of the transducer is 1 in 10,000 of full scale over the calibrated temperature range. The overall accuracy of the system is better than +/- 3 mm for a known water density. Data is retrieved from the gauges by lowering a coil assembly on the end of a cable over a projecting knob on the top of the gauge and by use of an interface unit, a serial connection can be established to the gauge. Time setting and data retrieval can be then achieved. Data has been retrieved from this gauge once since deployment. The records are complete since deployment. Conversion of raw data to tidal records is done as detailed in document: Details of Conversion of Raw Data. Levelling One attempts has been made at establishing an absolute height for this gauge using timed water level measurements. Documentation dated 2008-10-17 Zhong Shan. The battery in the submerged gauge at Zhong Shan has probably been exhausted. The gauge will be removed at an opportune time. The gauge has not recently been download. There will still be some records available.

Over time there have been a number of tide gauges deployed at Macquarie Island Station. The data download files contain further information about the gauges, but some of the information has been summarised here. Note that this metadata record only describes tide gauge data from 1993 to 2007. More recent data are described elsewhere. Macquarie Island used Aquatrak and Druck tide gauges during this period. Documentation from the older metadata record: Documentation dated 2001-06-12 The Macquarie Island Tide Gauge System The Macquarie Island Tide Gauge was first commissioned in November 1993. Since then every year attempts have been made to improve the performance of the system. The next improvement involves the installation of radio modems to effect a network link to the tide gauge dataloggers. Other improvements planned are include using the wave guide temperatures to correct the water heights for variations in the velocity of sound in air due to temperature gradients in the waveguide. The system consists of two separate sensors contained in separate housings on a rock shelf on the northern side of Garden Cove. One of the sensors is an Aquatrack acoustic type and the other is a Druck pressure transducer. Both housings contain a Platypus Engineering data logger and a battery. The housings consist each of an Admiralty Bronze ring bolted down to a concrete plinth and a glass fibre reinforced cover held down by a single central bolt and nut. Primary power for both installations comes from a solar panel array mounted on the northern side of the rock ridge behind the rock shelf. The solar panels are attached to an aluminium frame which is bolted to a galvanized steel frame cemented into holes in the rock face. The bolts are made of nylon with nylon washers so that the aluminium frame is not in contact with the galvanized frame. Mounted below the panels is a sealed plastic box with a hinged door. A multicore data cable runs from this box to the tide gauge housings. This cable is run inside a length of plastic conduit along with the power cable. The conduit is concealed in the vegetation and at the lower level is cemented into slots cut into the rock The batteries in the housing are kept charged by the solar panels but are isolated via power diodes, one in each housing. Either or both of the housing batteries or only the solar panel battery may be removed without interruption to data logging. The voltage of either housing battery may be found by interrogation of the appropriate data logger. Tide Gauge Bore Holes. Both gauges obtain access to the ocean via an inclined hole about 12 metres long inclined at approximately 34 and 39 degrees to the horizontal. Both holes are lined with a plastic pipe which is normally not removable. In the Aquatrack sensor hole a 50mm ABS pressure pipe runs down inside the liner and is fitted with a brass strainer and orifice at the lower end. This strainer protrudes into the ocean somewhat clear of the sea floor (see figure). Inside the 50mm pipe runs a 15mm diameter plastic pipe. The bottom end of this is fitted with a 600mm length of red brass tubing and stops about 100mm from the orifice at the bottom of the pipe. The 15mm pipe is held central in the 50mm pipe by three armed spiders placed about every metre down the pipe. The top end of both pipes is secured by a flange with two O rings and stainless steel screws. On top of the 15mm pipe is mounted the Aquatrack acoustic sensor the 15mm pipe acting as a waveguide for sound pulses from the sensor (see figure ). The Aquatrack sensor measures the distance of the water surface from a reference point on the sensor. About one metre down the wave guide is a small hole. This has two functions. One is to act as vent to allow water to rise and fall in the wave guide and the other is to provide an acoustic reflection at a known distance down the wave guide. This allows compensation for velocity of sound changes due to temperature changes. The Aquatrak wave guide

Tides were measured using a portable pressure transducer secured just below low water line. A 30 day record was obtained. Numerous manual water level measurements were made to connect the tide gauge to the local benchmark. From these observations a local mean sea level was obtained. Documentation dated 2001-03-07 Beaver Lake and the Stillwell Hills In Dec 1996 - Jan 1997 a temporary pressure type tide gauge was deployed at Beaver Lake and the Stillwell Hills in open water. Timed water level measurements were made over this period. From these data a value for MSL was found for Beaver Lake and the Stillwell Hills.

Tide gauge data collected from pressure tide gauge at Hurd Point, Macquarie Island. Data were collected between 1996-03-07 and 1996-10-27. A temporary tide gauge was installed at Hurd Point as it was suspected that there was a 6 minute wave around the island. The installation was made to determine whether this is correct. Photo Oblique aerial photos showing location of tide gauge, bench mark AUS188 and Hurd Point trig and photo mof GPS set up. Gravity meter set up adjacent tide gauge Temporary Bench Mark Survey Scans of survey field notes showing location of tide gauge in relation to Hurd Point huts, AUS188 and old Auroral Camera stand, vertical differences between AUS188, tide gauge temporary mark and tide gauge housing.

Tides were measured using a portable pressure transducer secured just below low water line. A 22 hour record was obtained. A connection was made to the local Pageos benchmark by leveling and a 2 hour GPS observation. Additionally, the National Tidal Centre also has tidal data from Heard Island for 1948, 1980 and from 1986-1987. Documentation dated 2001-03-07 Heard Island Tide Gauge. A Platypus Engineering tide gauge was deployed in a heavy steel tetrahedral mooring in Atlas Cove in 1993. Two attempts have been made to recover the gauge without success. In March 1997 a temporary tide gauge was used to obtain a 22 hour record. A rock bolt was placed in the rock close to the deployment site and a connection was made to the Pageos Site by a 2 hour GPS observation. A level and staff was used to measure the height of the temporary gauge relative to the BM (AUS258). From these observations an approximate MSL can be found. Some further information about the data can be found in the download file.

Over time there have been a number of tide gauges deployed at Casey Station, Antarctica. The data download files contain further information about the gauges, but some of the information has been summarised here. Note that this metadata record only describes tide gauge data from 1996 to 2007. More recent data are described elsewhere. Old Tide Gauge 2 (TG002_Old) Oldtg02 is a download from the first gauge submerged deployed at Casey in 1992. This gauge was lost but later recovered standing upright in the mud. The gauge overwrote its memory and stopped. The record runs from 02/04/97 to 08/09/99. It is highly probable that the position of the gauge was stable during this period. There is data from the same period from gauge TG06. Tide Gauge 2 (TG002) These folders contain data downloaded from the redeployed gauge TG02. TG02 was redeployed in November 2003. The Record runs from 12/11/03 to 4/3/05. It is expected that data will be downloaded from this gauge for the next 4-5 years. This gauge was deployed after the previously deployed gauge ran out of battery energy. There is therefore a substantial gap in the record prior to 12/11/03. Tide Gauge 6 (TG006) Tg06 was deployed at Casey in March 1996. The battery became exhausted in June 2003. The gauge was replaced by TG02 in Novenber 2003. There is therefore a gap in the data between June and November 2003. Tide Gauges 33, 34 and 36 (TG033, TG034, TGA001, TG036) There are two wharf pressure sensors at Casey separated vertically by 2.007 m. There is also a barometer in the wharf hut. The files in this folder are from the old tide gauge data loggers. There are three loggers, TG33 records pressures from lower water pressure gauge as 30 second average values (absolute pressure mbar). It also records wharf tube water temperatures. This logger also streams 30sec average pressure. TG34 records pressures from upper water pressure gauge. This logger also streams 30sec average values as and 10minute average water pressure data. TGA01 (and later replaced by TG36) records air pressure as 10 minute average values in mbar. Further documentation from the old metadata records: Documentation dated 2001-03-07 Casey Submerged Tide Gauge The gauge used at Casey was designed in 1991/2 by Platypus Engineering, Hobart, Tasmania. It was intended to be submerged in about 7 metres of water in a purpose made concrete mooring in the shape of a truncated pyramid. The gauge measures pressure using a Paroscientific Digiquartz Pressure Transducer with a full scale pressure of 30 psi absolute. The accuracy of the transducer is 1 in 10,000 of full scale over the calibrated temperature. The overall accuracy of the system is better than +/- 3 mm for a known water density. Data is retrieved from the gauges by lowering a coil assembly on the end of a cable over a projecting knob on the top of the gauge and by use of an interface unit, a serial connection can be established to the gauge. Time setting and data retrieval can be then achieved. One of these of these gauges was deployed at Casey in early 1992 in a mooring in Geoffrey Bay. The mooring was apparently moved by sea ice and was later found, but the gauge is missing. A new mooring, one which was originally made for Harry Burton for use in one of the Vestfold Hills lakes, was taken by ship to Casey and was placed in Geoffrey Bay using a collection of 200 litre fuel drum to float the mooring into position. A new gauge was deployed in March 1996. The gauge was lowered into position with the holding grab wired closed to check that the device fitted in the mooring. The gauge became jammed so was left in situ with the grab preventing access to downloading. In April that year Roger Handsworth attached weights to the floating ropes of the grab to sink them out of the way of the freezing surface water. Divers located the mooring and gauge in late 1997 and 22 months of tidal records were retrieved. The gauge was restarted to clear the memory and allow another two years of data

Over time there have been a number of tide gauges deployed at Mawson Station, Antarctica. The data download files contain further information about the gauges, but some of the information has been summarised here. Note that this metadata record only describes tide gauge data from 1992 to 2016. More recent data are described elsewhere. Tide Gauge 1 (TG001) 1992-03-05 - 1992-05-13 This folder contains monthly download files from the first deployment of a submerged tide gauge at Mawson in March 1992. These files are ASCII hexadecimal files. They need to be converted to decimal. The resultant values are absolute seawater pressures in mbar. Tide Gauge 4 (TG004) 1993-03-22 - 1999-12-29 This folder contains the following folders:- old_tidedata monthly download files from the second deployment of a submerged tide gauge at Mawson in March 1993. These files are ASCII hexadecimal files. They need to be converted to decimal. The resultant values are absolute seawater pressures in mbar. raw memory images from submerged tide gauge. file extension is memory bank number. These files are processed by a utility called tgxtract.exe which creates files in same format as those in old_tidedata folder. These file have extension .srt. They are then converted to decimal pressure values. interim files produced during processing of .raw files. output output file (.srt) which have been sent to BoM. Tide Gauge 13 (TG013) 2014-06-04 - 2016-11-04 Tide Gauge 20 (TG020) 1999-11-05 - 2009-12-21 This folder contains the following folders:- raw memory images from submerged tide gauge. file extension is memory bank number. These files are processed by a utility called tgxtract.exe which creates files in same format as original download format. These file have extension .srt. These files are ASCII hexadecimal files. They need to be converted to decimal. The resultant values are absolute seawater pressures in mbar. interim files produced during processing of .raw files. output output file (.srt) which have been sent to BoM. Tide Gauge 41 (TG041) 2008-03-02 - 2010-11-16 This folder contains the following folders:- raw memory images from submerged tide gauge. file extension is memory bank number. These files are processed by a utility called tgxtract.exe which creates files in same format as original download format. These file have extension .srt. These files are ASCII hexadecimal files. They need to be converted to decimal. The resultant values are absolute seawater pressures in mbar. interim files produced during processing of .raw files. output output file (.srt) which have been sent to BoM. Documentation from older metadata record: Documentation dated 2001-03-26 Mawson Submerged Tide Gauge The gauge used at Mawson was designed in 1991/2 by Platypus Engineering, Hobart, Tasmania. It was intended to be submerged in about 7 metres of water in a purpose made concrete mooring in the shape of a truncated pyramid. The gauge measures pressure using a Paroscientific Digiquartz Pressure Transducer with a full scale pressure of 30 psi absolute. The accuracy of the transducer is 1 in 10,000 of full scale over the calibrated temperature range. The overall accuracy of the system is better than +/- 3 mm for a known water density. Data is retrieved from the gauges by lowering a coil assembly on the end of a cable over a projecting knob on the top of the gauge and by use of an interface unit ,a serial connection can be established to the gauge. Time setting and data retrieval can be then achieved. The first of these gauges were first deployed Mawson in early 1992 in a a mooring in Horseshoe Harbour. The gauge was found to have some communications problems and was removed in May 1992. Tidal records from 6/3/92 to present have been retrieved from it. A new gauge was deployed at Mawson in March 1993. Data has been retrieved from these gauges irregularly since then. The records are complete since deployment except for a few days in late 1995. The loss was caused by a fault in the

This dataset contains current meter data from Prydz Bay, Antarctica. Current meters were deployed on 3 moorings around Prydz Bay between January 1986 and February 1987. Summary results and deployment details are in the documentation. Temperature and salinity were also recorded. Records are not continuous at each site over this time period. Each mooring contains three or four current meters, measuring water temperature, speed and direction, and for some meters conductivity. Moorings 1 and 2 consisted of four Aanderaa current meters with target meter deployment depths of 200m, 350m, 500 m and near bottom. Mooring 3 had three Aanderaa current meters, with depths of 200m, 350m and near bottom. The fields in this dataset are: DEVICE IDENTIFICATION SAMPLE PERIOD TEMPERATURE PARAMETERS CONDUCTIVITY PARAMETERS SEA CURRENT DIRECTION PARAMETERS SEA CURRENT SPEED PARAMETERS DATE TIME TEMPERATURE (DEGREES C) SALINITY (Ppt) DIRECTION (degrees) SPEED (knots)

This dataset contains current meter data from Prydz Bay, Antarctica. Four moorings each consisting of four current meters were deployed at various locations in Prydz Bay. Data was obtained between January 1985 and February 1986. Each of the four current meters per mooring measured time, water temperature, speed and direction every sixty minutes. Moorings 1 and 3 also each had one current meter equipped with a pressure sensor. All meters on mooring 4 measured pressure and conductivity. The four meters on each mooring were positioned at the intended depths of 200m, 350m, 500m and near-bottom. Eleven of the sixteen current meters deployed were recovered with data intact, and summary results and deployment details are given in the documentation. The fields in this dataset are: DEVICE IDENTIFICATION SAMPLE PERIOD TEMPERATURE PARAMETERS CONDUCTIVITY PARAMETERS SEA CURRENT DIRECTION PARAMETERS SEA CURRENT SPEED PARAMETERS DATE TIME TEMPERATURE (DEGREES C) SALINITY (Ppt) DIRECTION (degrees) SPEED (knots)

This metadata record is a modified child record of an original parent record originating from custodians of data associated with Geoscience Australia (The identifier of the parent record is ANZCW0703006701, and can be found on the Australian Spatial Data Directory website - see the URL given below). A bathymetric grid of the Macquarie Island Region (Longitudes 151 E and 167 E, Latitudes 48 S and 62 S) was produced. In doing so, the individual datasets used were closely examined and any deficiencies noted for further follow up or were rectified immediately and the changes documented. These datasets include modern multibeam data, coastline data obtained from georeferenced SPOT imagery, hydrographic quality data, echosounder data from research and fishing vessels and satellite derived bathymetric data. A hierarchical system was employed whereby the best and most extensive datasets were gridded first and applied as a mask to the next best dataset. A new masking grid would be formed from these datasets to pass non-overlapping data in the next best dataset. This procedure was employed until finally the satellite data were masked. All the various levels of masked data were then brought together by the gridding algorithm (Intrepid and Desmond Fitzgerald Associates) and an ERMapper format grid produced. A grid cell size of 0.00225 (nominal 250m) was used with many iterations of minimum curvature gridding and several passes of smoothing. The final grid is available in geotiff, ArcInfo ascii and xyz text formats. A detailed report of the work completed is also available.