Antarctica — Monitoring the ice sheet

by Mike Moore

Last summer, over 2,500nm south-south-west of Perth and over 400km from the nearest Australian National Antarctic Research Expeditions (ANARE) base, a diesel mechanic Graeme Wilsey, and two members of the School, Volker Janssen and Mike Moore, set up camp for a month on the Amery Ice Shelf as part of a program to monitor the ice sheet mass balance of Antarctica.

The Amery Ice Shelf, the third largest in Antarctica, is an important location for glaciologists trying to understand how the growth or shrinkage in an ice shelf is related to climate and sea level change. To aid the modeling and monitoring of the Amery Ice Shelf, numerous satellite measurement techniques were put into action. The rate of movement of the ice sheet was determined through a series of repeat GPS measurements of markers (a mixture of aluminum poles and used Holden axles!) placed in the snow surface. This project also involved a 150km kinematic GPS traverse by skidoo to measure any changes in elevation in the three decades since Australian glaciologists carried out an optical levelling survey of the region.

Caption: Graeme Wilsey, Volker Janssen, and Mike Moore returning to base camp, Amery Ice Shelf, Antarctica.

For long-term monitoring, earlier in the summer we deployed six semipermanent GPS stations around the perimeter of the ice shelf. It is hoped that data obtained will provide further information on ice shelf dynamics and its tidal motion, as well as defining the grounding zone of the Amery Ice Shelf.

The working routine on the ice shelf was completely dictated by weather conditions, but typically the winds would die down by midday, allowing a quick lunch of cheese, salami and chocolate. Around 2:00am the temperature would drop to around –30°C, and the winds would pick up again. Faced with long periods of inactivity between blizzards, the team made the most of things by trying to come up with the best possible out-dated dehydrated food mixes for dinner (I’ll swear by the fettuccini of ’88), playing chess and re-reading books.

For further information phone +61 2 9385 4182 or visit www.gmat.unsw.edu.au/snap