Tide Gauge Records, Casey, Australian Antarctic TerritoryEntry ID: Casey_TG_1
Abstract: Tides are measured using a submerged pressure type gauge secured in a heavy concrete mooring at Casey.
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 2001-03-07
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A new mooring, one which was originally made for Harry Burton for use in one of the Vestfold Hills lakes, was taken by ship to Casey and was placed in Geoffrey Bay using a collection of 200 litre fuel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 to be collected without any problems from a small software bug.
Conversion of raw data to tidal records is done as detailed in document DATAFORMAT1.DOC .
In December 1997 a set of water level observations were made by the station leader. These observations have been sent to National Tidal Facility, Flinders University, SA to derive a value for mean sea level.
Documentation dated 2008-10-17
There is one submerged bottom mounted gauge at Casey. (TG02)
The wharf based tide gauge installation at Casey has been upgraded with 2 Campbell Scientific CR1000 dataloggers.
One logger (Main) receives signals from two wharf installed submerged Paroscientific Digiquartz pressure sensors and a barometer. The other logger (Backup) receives signals from only the two submerged sensors.
Pressures are recorded in hPa, temperatures from the Digiquartz sensors in degrees C and temperatures from thermistors in the water column in unscaled A/D values.
The two submerged pressure sensors are separated vertically by 2.007 metre.
The backup logger streams 30 second average pressure values from both submerged sensors.
The main datalogger records 3 pressure and 6 temperatures and controls the water heaters.
(Click for Interactive Map)
Start Date: 1996-03-08Stop Date: 2003-06-20
Quality The dataset extends from has two gaps, from January to June 2000 and from 20-23 November 2003. There will be a large gap in the datset after the time the gauge ceased to function as the gauge was not immediately replaced. A chart showing what data are available (&Chart of Available Data& - correct as of 2005-07-20). Pressure and temperature data are retrieved from the submerged gauge when time and weather allow. The records are in hex format. Records are stored as datalogger memory images and must be processed to extract tide gauge records. Tidal records are checked for gross errors in height values and obvious timing errors. Further checks are done by NTC during processing.
Access Constraints Records are stored in the form in which they are retrieved from the tide gauges. Futher processing is done by the National Tidal Centre. Processed data are available in graphical form from the National Tidal Centre.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at the URL below when using these data.
Data Set Progress
Distribution Format: hex
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: +61 3 6232 3528
Fax: +61 3 6232 3351
Email: mapping at aad.gov.au
Australian Antarctic Division 203 Channel Highway
Province or State: Tasmania
Postal Code: 7050
Creation and Review Dates
DIF Creation Date: 1999-10-07
Last DIF Revision Date: 2008-10-29