NZ scientists saddle up for 350km Antarctic road trip

Antarctica NZ field training instructor Tom Arnold tests out a crevasse-detecting radar that will be used by a research expedition to a remote site on Antarctica's Ross Ice Shelf. Photo / Supplied

A bit of Kiwi ingenuity and an epic road trip will ultimately help a team of New Zealand scientists understand how Antarctica's vast Ross Ice Shelf might respond to future warming under climate change.

An Otago University-led research team is this month heading down to the frozen continent, where they'll drive tracked Hagglund vehicles and snowmobiles 350km from Scott Base to a field site atop what, at roughly the size of France, is the world's largest ice shelf.

The team will spearhead the expedition with a Hagglund rigged with a boom-like device, made from tyres and other materials and instruments, that extends forward from the vehicle and which can pick up crevasses below the ice with radar.

Hidden underfoot is an ocean of greater volume than Europe's North Sea, and all of it largely unexplored.

Getting all of the gear to the far-flung site was only practicable by first driving along a route that was established by an annual United States traverse toward South Pole - the first tracked traverse began just 60 years ago with the famed party led by Sir Edmund Hillary and Dr Vivian Fuchs - and then veering left into uncharted territory.

Camping out on a constantly-moving layer of ice, about 350 metres thick, the team will use a heavy seismic device, designed by Otago University scientists, to provide a sound source for acoustic-based imaging of the seafloor and its sediment layers.

A deep sounding radar will also be used to study interaction between ice at the base of the ice shelf and the underlying ocean.

Next spring, the scientists will use a hot water drill built at Victoria University to bore through the ice to observe the interface of the ice and ocean directly, as well as measure ocean properties and sample sediments on the sea floor.

Later, similar studies will be carried out at another site east of the ice shelf.

Dr Christian Ohneiser, a member of the team, said state-of-the-art techniques would be used to analyse the seafloor sediment cores, enabling him to reconstruct the ice shelf's history since the last ice age.

"We will use this reconstruction to test computer models of past change in order to improve models forecasting future change."

Professor Christina Hulbe, the dean of Otago University's School of Surveying and leader of the research programme, said the ultimate goal was to understand the processes in the entire ice shelf and ocean system that mattered most for change in the system.

"We know that the past climate warming caused ice shelf and ice sheet retreat in the Ross Sea," she said.

"Now we need to find out more about the actual physical processes and the rates at which they acted in the past.

"That knowledge is one of the keys to making better projections of future change."

Being a major interface between the West Antarctic Ice Sheet (WAIS) and the warming ocean, the Ross Ice Shelf's response to climate warming could put the WAIS - packing 2.2 million square kilometres of ice volume and already under threat from the Amundsen Sea region - at even greater risk of collapse.

That in turn would accelerate global sea level rise, and newly-published research has projected the WAIS's potential contribution could be an extra three metres of sea level rise.

That work followed the publication of a model-based study in the journal Nature, led by Victoria University's Dr Nicholas Golledge, that found warming would lead to the loss of large parts of the wider Antarctic ice sheet, resulting in a substantial rise in global sea level.

The only scenario in which this didn't play out was if emissions could be significantly reduced beyond 2020.

People can follow the expedition through this Instagram account.