Ice research team breaks new ground
It takes two days of constant driving across 350 kilometres of barren ice to reach the tiny tent settlement where Kiwi scientists are drilling right through the frozen continent.
At a top speed of 20kmh, the undulating white landscape seems endless, and the crews stop only to sleep, retreating to a towed cabin with four simple bunks.
Finally the small settlement of tents appears. It is among these seemingly flimsy structures that engineers and researchers are conducting a piece of groundbreaking research.
For the first time, the scientists are boring into the heart of the Ross Ice Shelf, through hundreds of metres of frozen ground to reach the oceans below.
Their research aims to discover how warming oceans may be eroding the shelf from below, which could have massive implications for estimates of global sea level rises.
Victoria University geologist Gavin Dunbar said planning for the trip stretched back years. ‘‘This is one of the bigger projects New Zealand has done in Antarctica.’’
Engineers arrived in October to begin setting up the camp equipment, with the expedition possible only because of two new longrange snow tractors, capable of towing 60 tonnes.
‘‘In the past, we have had to operate pretty close to Scott Base,’’ Dunbar said.
The boring rigs use near-boiling water, melted from the surrounding snow, to create a 30-centimetre hole through the ice.
When the jet finally meets the sea water, researchers can peer down through a 370-metre tunnel into the Antarctic Ocean.
‘‘It’s really like watching the jump to hyperspace, the images from cameras going down into the ice, and then you come out the bottom into the ocean.’’
The ice is so clear it appears black in the camera light, with small spots of light created by ice crystals.
It is another 410m between the ice and ocean floor.
The only other bores of this kind were made in the 1970s, and the instrumentation available back then was rudimentary compared with the devices being lowered into the ocean today.
‘‘This is really very pioneering stuff,’’ Dunbar said.
‘‘The underlying thing we are trying to understand is the stability of this ice and, by looking at the property of the ocean beneath it, we can get a sense of how stable it has been in the past.
‘‘In the past the Earth has been warmer than it is now, and what we want to know is whether the ice shelf was there or not – in other words, how warm does it have to get before that big chunk of ice disappears.’’
Early indications suggest there is no extensive melting of the shelf from below, with trapped stones and grit suggesting melting at the base has been minimal, remaining trapped since the ice flowed down from the Antarctic continent 400 years ago.
Much of the equipment will be left below, secured to the ice, recording temperatures and ocean activity for years to come.
For the scientists, their time in the Antarctic is now over, with nine of the team, including Dunbar, flying back to New Zealand on Saturday.
This was Dunbar’s ninth trip to the frozen continent, and if there had been one lesson learned on one of New Zealand largest expeditions to date, he said it was to pack more coffee.