Over The Horizon

Breaking the Ice

Alex Pyne and Stuart Henrys of Victoria University moved with alacrity when they received an unexpected offer of the use of an icebreaker. Receiving the offer on a Thursday at Victoria, by the next Monday they'd put together a research proposal, had it approved, flown south and put to sea.

The US Coastguard's Polar Star had found itself at McMurdo with no scheduled activities, and the US National Science Foundation offered the use of it to the New Zealand Antarctic Program. The researchers used their windfall to map the ocean floor off Victoria Land in areas where future research is planned.

"By using the ship's echo-sounder we were able to make some very detailed maps of the ocean floor, both its depth below the sea and in some places the nature of the near-surface layers." says Pyne. "We identified some promising sites for future work with our own vibra-corer [see "Icy Cores" NZSM, Dec/Jan 1992/93] and some offshore drilling we are planning..."

The map will help in selecting sites for exploration, where the corer will take samples from the soft surface layers and the drilling will go down several hundred metres. This will give useful information on the geological history of Antarctica and the ice sheet's waxing and waning, which has an important bearing on the current global warming debate.

Pyne notes that the mapping work would have been impossible without the use of the 13,000 tonne icebreaker.

"Wewere very impressed with the ship and its crew. They were very keen to help us get as much done as possible," he said.