2024 01 12 cross ant circle Craig Stevens

Sea ice in the Antarctic circle. Photo: Craig Stevens.

Ross Sea Voyage Update #2: Crossing the Line

12 January 2024

We crossed the Antarctic circle today (66° 34’S), and just last night we spotted our first berg through the fog.

It's worth reflecting that James Clark Ross was not so far away (south of Tasmania) when Erebus and Terror crossed the line on New Year’s Day 1841. They too were on a mission to discover more about Antarctic ice, magnetism and oceans. However, they were crossing into the Antarctic circle right about the time the early onset of industrial-era anthropogenic impact on our atmosphere was happening (Abram et al. 2016). 

While we’re now amongst sea ice, the sea-ice distribution this season is low, as expected given media exposure on the issue of vanishing sea ice. The ice here is concentrated along the Victoria Land Coast, as well as a patch to the North-East of the continental shelf towards the Ross Gyre. Despite the limited ice, it will challenge some of the research locations we want to access along the coast, but the majority of our work is further east.

The good weather won’t continue, so our initial research location has been postponed. Instead, we’ll head in towards Terra Nova Bay to start work there, and access the initial location on the return leg. This revised route will keep us close by the Italian base, Mario Zuchelli Station, where cargo will be unloaded over a few days and personnel exchanged. We’ll gain the rest of our New Zealand team before heading along the Ross Ice Shelf. 

2024 02 13 surface drifter Lana Young

About to deploy the surface drifter. Photo: Liv Cornelissen.

Our time on board so far has been occupied with setting up gear, including familiarising ourselves with multi-coring gear lent to our project by Tommaso Tesi’s research group from Bologna. Our Italian colleagues, ship’s skipper and crew are being very helpful and accommodating. We’ve managed to integrate our significant amount of gear relatively seamlessly, despite it being the first time for a shared mission.

The Italian national Antarctic research programme has invested heavily in upgrading the vessel’s science capability. They’ve installed a Baltic room and adjacent hydrolab for CTD rosette deployments and water sample processing, and brought two ocean gliders to complement the NIWA glider we will deploy on this voyage. The sea ice and weather mean we are already into several iterations of plans for the Argo-float and mooring operations, and ocean glider missions. Ultimately, we hope to run three gliders in parallel. 

We have deployed instruments:

  • The XBT (eXpendable BathyThermograph) - a probe that measures the temperature as it falls through the water;
  • surface drifter – devices that float on the ocean surface, tracked by satellite, to investigate ocean currents and other parameters; and
  • multibeam and echo sounder – to map the seafloor.

One component of the work is already well underway: the seabird survey work from Matthias Dehling (from Monash University, and formerly a postdoc at University of Canterbury). Matthias has put in solid days on the bridge and helo deck doing visual surveys as the species composition changes with latitude. The newest addition to the species list is the Antarctic petrel, added just today.

Matthias birdwatching. Photo: Lana Young

Matthias birdwatching. Photo: Lana Young

Juvenile light mantled sooty albatross Lana Young

The light-mantled sooty albatross. Photo: Lana Young.

2024 02 09 adelies diving Lana Young

Adélie penguins are found on the Antarctic continent and neighbouring islands. Photo: Lana Young.

We ended up taking a westerly route to sneak between two weather systems, so the transit so far has been quite smooth sailing, with only one uncomfortable night. The smooth sailing to date has allowed the New Zealand team to get its sea legs nicely. We’ve had daily first aid refreshers, a knot tying session and some science talks. We are also producing phrases of the day, in both Italiano and te reo Māori.

This update was sent from the ship by voyage leader Prof Craig Stevens and revised by the New Zealand-based communications team.