A six-member Antarctica New Zealand crew embarks on an arduous 1100km journey across the Ross Ice Shelf. Photo / Anthony Powell / Antarctica NZ
A six-member Antarctica New Zealand crew embarks on an arduous 1100km journey across the Ross Ice Shelf. Photo / Anthony Powell / Antarctica NZ
It reads like a Hollywood plot – a team crossing crevasse-riddled sea ice to drill 500m for geological evidence that could reveal when the West Antarctic Ice Sheet might collapse, driving sea-level rise and impacting millions worldwide.
The New Zealand-led international team of scientists, drillers, engineers and support staff isundertaking the third season of the SWAIS2C (Sensitivity of the West Antarctic Ice Sheet to 2C) project.
The ice sheet is roughly the size of Mexico, on average 1km thick, and holds enough ice to raise global sea level by four to five metres if it melts completely.
SWAIS2C aims to use sediment layers from past warm periods – when the ice sheet retreated significantly – to help assess the scale of future sea-level rise driven by melting ice.
“The information we’re seeking about when and how much of the West Antarctic Ice Sheet we will lose is vital to help the world better adapt and prepare for sea-level rise, especially for the 680 million people living in low-lying coastal areas,” said co-chief scientist Huw Horgan from Te Herenga Waka – Victoria University.
Before drilling could begin, a six-member Antarctica New Zealand traverse crew embarked on an arduous 1100km journey across the Ross Ice Shelf.
The Antarctica New Zealand traverse crew departs New Zealand’s Scott Base on November 8. Photo / Anthony Powell / Antarctica NZ
Starting on November 8, in a convoy of PistenBully polar vehicles, they hauled the supplies needed to sustain the camp for the eight-week mission, using ground-penetrating radar to avoid treacherous crevasses, arriving on-site 13 days later.
Since then, the team has set up camp and cleared a skiway for ski-equipped aircraft, with the first drillers and scientists landing at the site on December 12.
The journey of the Antarctica New Zealand traverse crew to set up the Carey Ice Rise camp. Infographic / Antarctica NZ
The 29-strong on-ice team will be living in tents on the snow and working in shifts around the clock to make the most of the limited time at this remote site. It is hoped the scientists will complete their work by mid-January.
“This is Antarctic frontier science, and what we’re trying to do is complex and hugely challenging, from an engineering and logistical perspective as well as being world-leading science,” Horgan says.
“We’ve made great progress over the first two seasons and have modified the drilling system for success this year.”
The first two SWAIS2C seasons took place at a site about 260km from Crary Ice Rise, but both were thwarted by technical issues with the custom-designed drill.
No team has successfully obtained a deep sediment core this far from a base or so close to the centre of the West Antarctic Ice Sheet.
Drillers assemble sections of sea riser pipe at the 2024 SWAIS2C drilling site. Photo / Ana Tovey
Once the drill penetrates the 500m of ice, it will retrieve a 200m sediment core – cylindrical samples of mud and rock that may reveal the recent geological history of the ice sheet and sediment layers stretching back 23 million years, including periods when Antarctica was warmer than today.
“We’ll analyse the samples to collect environmental data about how the Ross Ice Shelf responded in these past times of warmth. This record will help us build a much clearer picture of what temperature will trigger the retreat of the West Antarctic Ice Sheet and significant sea-level rise,” explains co-chief scientist Molly Patterson from Binghamton University.
More than 120 scientists from 10 countries will study the cores, searching for tiny microfossils of marine algae – organisms that require light to survive. Their presence deep beneath the ice would suggest past open-ocean conditions and a retreat of the Ross Ice Shelf.
This is not the first Antarctic drilling operation involving New Zealand scientists. The Antarctic Drilling Project, known as Andrill, recovered sediment cores from beneath the Ross Ice Shelf to reconstruct past climates in the McMurdo region.
