Other formats

    Adobe Portable Document Format file (facsimile images)   TEI XML file   ePub eBook file  


    mail icontwitter iconBlogspot iconrss icon

Victoria University Antarctic Research Expedition Science and Logistics Reports 2004-05: VUWAE 49


page break


K042: Cape Roberts Tide Gauge

Antarctica New Zealand 2004/05

page 1

Proposed Programme & Work Achieved


The permanent Cape Roberts Tide Gauge has been operating since November 1990. After 12 years of operation LINZ and the Antarctic Research Centre of Victoria University of Wellington proposed refurbishment and modernisation in a co-sponsored program. In November – December 2002 the equipment was refurbished and modernised (Annex 2). In March 2003 the new data logger failed and data was not recorded until 26 November 2003 when a temporary replacement logger was installed. (Annex 1)

Proposed Program

In the 2004/05 season it was proposed to:
  • Replace the temporary data logger with the new repaired unit.
  • Check and re-level the transducer where it exits the coastal rock in the sea. This was unsuccessful in 2003/04.
  • Carry out the annual calibration of the tide gauge using GPS methods from the near shore floating sea ice platform (see LINZ event K450 for details).
  • Consider options for future including transducer installation, metrological measurements and real time data recovery in conjunction with the continuous GPS station at Cape Roberts co-sponsored by LINZ and the USGS.

Equipment Replacement

The repaired Campbell CR10X was reinstalled and the temporary unit returned to McMurdo Station Crary Lab.

Transducer levelling

This procedure was successful and required two days this season. The following procedure was carried out:
  • Drilling through the sea ice foot (approx 5-6 m thick) with a 200 mm diameter auger directly above the position where the transducer exits the submerged rock.
  • Melting out ice in the 12 m long transducer casing using a mini hot water drill built for the purpose.
  • Temporarily installing lighting and a submarine video camera in the tide crack approximately 3-4 m from the transducer position to locate the transducer under the sea ice foot.
  • Locate the levelling probe on the transducer and level back to the Tide Gauge Bench Mark (CRTG BM1).
  • Levelling Result: Transducer is 8.016 m below CRTG BM1.

The fast sea ice near shore to the tide gauge has remained in place for at least the last 3 years and probably has prevented flushing of ice from under the ice foot that would normally occur when the near shore ice and ice foot breaks away in late summer (Jan-Feb). A previous event affecting the tide gauge on 20 February 1997 has also shown that by late in the summer warming has occurred in the surrounding rock so that ice in the transducer casing can melt completely and potentially would allow the transducer to move from its location. A film of ice has grown on the submerged rock surfaces in the sub ice foot cavity over the last 3 years, obscuring the transducer but the ice is permeable so has not affected the tidal measurements. However the calibration measurements have indicated a nonlinear progressive shallowing of the transducer. Video observation this season showed that the transducer had physically moved up the casing and this page 2 probably occurred progressively as the last three years calibration results (shown below) would indicate.

(Derived from LINZ calibration measurements and data processing)
Height of reference mark above Tide Gauge Zero
CAPE ROBERTS (Cape Roberts TGBM1 (B93M))
2000 – 2001 8.553m
2001 – 2002 8.506m
2002 – 2003 8.332m
2002 – 2004 8.196m

The extended period of multi year fast ice near shore to the tide gauge has had an adverse effect on the tide gauge data. The transducer position should remain fixed for reliable long-term measurements but this is not guaranteed at present where the transducer is held in the cage by gravity and relies on ice in the casing locking it into position. A more reliable construction would be to replace the existing plastic transducer casing and locating cage with a new casing and J slot locking system that locates and locks the transducer. The techniques and equipment now developed to level the existing transducer would to used also to replace the transducer casing.

Annual Calibration

This was successfully carried out both prior to transducer levelling and after when the transducer was located in the correct position. (See K450 reports for detailed information).

Future work

  • Replace the transducer casing with a new plastic casing that allows the transducer to be locked into position and enables recovery for maintenance or replacement.
  • Consider what meteorological information should also be measured in conjunction with both the tide gauge and the continuous GPS tracking station at Cape Roberts.
  • Continue to pursue real time data capability for the GPS station, tide gauge and additional metrological measurements.
  • Continuing annual calibration and data retrieval is required.


Goring, D. G., and A. R. Pyne (2003), Observations of sea- level variability in the Ross Sea, Antarctica, New Zealand Journal of Marine and Freshwater Research, 37, 241 – 249.

Han, A. S. K., (2002), An investigation into the Tidal Regime at Cape Roberts in Ross Sea, Antarctica. BSc (Hons) University of Otago, Dunedin, New Zealand.


We wish to acknowledge the continuing logistic support from Antarctic New Zealand. This program is co sponsored by Land Information New Zealand and the Antarctic Research Centre, Victoria University of Wellington, New Zealand.

page 3
Cape Roberts Tide Gauge Instrumentation. Solar Panel and instruments box. Meteorological mast (background) is not currently in use.

Cape Roberts Tide Gauge Instrumentation. Solar Panel and instruments box. Meteorological mast (background) is not currently in use.

Cape Roberts Tide Gauge Instrumentation and three 110 Ahr lead acid batteries.

Cape Roberts Tide Gauge Instrumentation and three 110 Ahr lead acid batteries.

page 4



Date Main Activities and Location Other Comments
Nov. 14-15 Cavanagh & Matheson (K450) to C. Roberts from Scott Base Hagglunds traverse
16 Pyne & Kingan to C. Roberts from Evans P. Gl. Transfer from K049 by Twin OtterREFUGE AND RESEARCH HUTS
16-19 Calibration, levelling and Maintenance of the tide gauge at Cape Roberts
19 Party of 4 return to Scott Base


refuge/research hut name Cape Roberts Huts
Overall condition Good
Scale and condition of provisions
Suitability of location
Unnecessary equipment or rubbish/debris in the area None, removed on previous K049 traverse 28-29 Oct.

Comment: Some Science equipment was left in the accommodation hut (Palace) for return in January to Scott Base ANDRILL LST container.


*Sites Visited

Site name Cape Roberts
Site location (coordinates/description)
Dates occupied 15-19 November
Total days (or hours) at site
Maximum number of people at site (your event) 4
Total person-days (or person-hours) at site 16 man days
Main activity undertaken Cape Roberts Tide Gauge
Cumulative impacts observed None


Chemical form Calcium Chloride
Quantity used 1 kg
Location of use
Purpose Melting ice at tide gauge transducer.


Chemical form Ethanol
Quantity used 5 litres
Location of use
Purpose Melting ice at tide gauge transducer.

Waste management

Location Cape Roberts
Approximate quantity Urine
Disposal methods Tide crack

Comment: Rubbish and solid human wastes returned to Scott Base