Hot water is playing a key role in understanding how Antarctic ice responds to a warming world.
Ninety percent of the world’s freshwater is locked up as ice in Antarctica and scientists are working to better understand what might happen with all that ice in a warming world.
Researchers from the Antarctic Research Centre at Victoria University of Wellington and from the University of Otago are studying the Kamb Ice Stream, an enormous river of ice that drains from West Antarctica and feeds the world’s largest floating ice shelf, the Ross Ice Shelf.
Scientists have discovered that ice streams turn on and off, stalling for decades and even hundreds of years before starting to move again. Huw Horgan, from Victoria University of Wellington, says that Kamb ice stream stalled about 170 years ago and researchers are investigating why.
The research is part of an Antarctic Science Platform project called Antarctic Ice Dynamics.
The 2019 research season took place on the Siple Coast, which is the grounding line of the West Antarctic Ice Sheet, where the ice meets the ocean and starts to float, becoming the Ross Ice Shelf. It is as far south as the ocean reaches anywhere in the world.
In hot water
The researchers use a hot water drill to melt through 600-metres of ice, to reach the water and sea floor below.
Driller Darcy Mandeno, from Victoria University of Wellington, says the drill will take about 12 hours to make a 35 centimetre diameter hole, through which the researchers can lower various instruments to measure physical attributes of the water, as well as drill a short sediment core.
The first full traverse across Antarctica was made by Sir Vivian Fuchs. Sir Edmund Hillary and his Kiwi team famously drove Massey Fergusson tractors to meet Fuchs at the South Pole, as part of the Commonwealth Trans-Antarctic expedition.
Every year, the United States Antarctic programme drives three traverses from McMurdo Station to the South Pole, dragging sleds carrying fuel and supplies.
In 2017, the Antarctica New Zealand started its own traverses, dragging scientific equipment to remote field camps on the Ross Ice Shelf.
Traverse navigator Daniel Price, a sea ice researcher at the University of Canterbury, selects safe routes for the traverse to follow. He uses satellite radar images to identify and plot large crevasses which must either be avoided or blown up to create a safe crossing.
Daniel says the most dangerous part of the South Pole traverse is a shear zone located just 40 kilometres from McMurdo. The zone contains multiple crevasses which need to be blown up with explosives and then filled with snow.
In late 2019, the New Zealand traverse took hot-water drilling equipment to the Siple coast area of the Ross ice shelf, which is where the Kamb ice stream is located. It was a 1100 kilometre journey.
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