Action in Antarctica
Each year, LINZ sends members from the geodetic team to complete an annual Antarctic programme with two main tasks to complete. This year our representatives were Glen Rowe, Paula Gentle and Rachelle Winefield.
The tasks included the calibration of two tide gauges, one at Cape Roberts and the other at Scott Base, and surveying of the historic huts.
The team repaired the broken tide gauge at Cape Roberts, which had been operating incorrectly for 18 months. Subsequently the annual calibration of the tide gauge was carried out to monitor the long-term results for sea level analysis.
Calibration involves deploying a GPS receiver on the floating sea ice, drilling a hole through the ice to obtain the height of water relative to the antenna. The purpose of this is to compare the tide measured by the GPS receiver to that measured by the tide gauge.
The Scott Base gauge was also in need of repair as a result of general wear and tear. These repairs were carried out by Scott Base staff. A similar methodology was used for the Cape Roberts calibration.
LINZ assists the Antarctic Heritage Trust in monitoring the vertical movement of Scott’s Terra Nova Hut at Cape Evans and Shackleton’s Nimrod Hut at Cape Royds.
In the past, ice build-up under the huts has resulted in vertical deformation. The huts have been surveyed by levelling annually since 2006, and before that during the 1980s and 1990s by DOSLI. There has been no significant deformation of the huts recently, possibly as a result of conservation efforts.
Rachelle is staying on in Antarctica to provide support for the POLNET project installing GPS receivers in remote parts of Antarctica. This is an international geophysical research project studying ice sheet change in a changing climate.
was led onto the ice by Rachelle Winefield.
