Photos: Diving Beneath Antarctica's Ross Ice Shelf
A team of scientists from Finland and New Zealand have arrived at McMurdo Sound in Antarctica to begin a six-week expedition diving beneath the Ross Ice Shelf.
The expedition aims to study how climate change has affected the rare ecosystems on the seafloor beneath the floating ice shelf, the largest and southernmost in the world. [Read more about the expedition]
As well as their scientific duties, the three Finnish team members are responsible for recording the work of the expedition in social media updates and in virtual reality, through the use of five 360-degree video cameras.
This will be the first time that an entire scientific field expedition has been documented in 360-degree video.
Their digital equipment also includes 32 digital cameras, three drones, a remote-controlled drone submarine – and hundreds of batteries to keep them all running.
Food for all
As well as their diving gear, air compressors, scientific equipment, computers, tents, sleeping gear, heaters, cookers and other items, the expedition is carrying one kilogram (2lbs) of food for each team member per day.
The expedition members arrived last week at New Zealand’s Scott Base in McMurdo Sound, a few kilometers from the large US Antarctic base, McMurdo Station.
The had planned to set out early this week, but several days of bad weather and low visibility kept them at the base until the weather cleared.
On Thursday the expedition moved out to the first of their two field sites on the Ross Ice Shelf, at New Harbour in the Ross Sea, about 80 kilometers (50 miles) from Scott Base.
After a four week stay diving and taking samples at New Harbour, the expedition will move to a second site, near Cape Evans on Ross Island, about 30 km (18 miles) from Scott Base.
The expedition is being supported in the field by the government agency Antarctica New Zealand, which uses snow tractors and helicopters to provide transport to the tent camps on the ice shelf.
The expedition members hope to dive beneath the ice up to four times a day.
The depth of the ice at the sites chosen for the diving work is typically three meters (9 feet) thick, and deep access holes for the divers must be melted through to the unfrozen water beneath by hole-melting equipment.
[Read more about the expedition]
A bit of history
Before the expedition left for the Ross Ice Shelf this week, they were able to visit Scott’s Hut near Cape Evans, which was built in 1911 for the British South Pole expedition led by the explorer Robert Falcon Scott.
The New Zealand and British Antarctic programs try to keep Scott’s Hut intact by periodically removing the ice and snow that builds up around it.
The hut contains many artifacts of the original expedition, including extensive supplies of canned food.
Now that the latest expedition is settled in at their first camp at New Harbour, they will begin by melting holes in the ice where they can undertake their first dives.
Both of the field sites are well known to scientists, who have been tracking changes to the seafloor ecosystems of the Ross Ice Shelf for more than 15 years.
Getting to camp
The researchers from New Zealand and Finland arrived in late October at their first camp on the ice shelf, at New Harbour in the Ross Sea.
They planned to spend 20 days at this site, diving beneath the floating ice shelf up to twice a day.
The expedition team is comprised of six researchers from New Zealand and three from Finland.
They are supported by staff from the New Zealand Antarctic program headquartered at Scott Base, at McMurdo Sound in the Ross Sea.
Diving beneath the ice first requires cutting and melting holes in the 3 meter (10 foot) thick floating ice shelf using a combination of hand-tools and ice-melting equipment.
Whenever two divers go into the water, a third is suited up and stands ready at the surface to help in case of an emergency.
Exploring the dark
The researchers are studying life on the sea floor beneath the ice shelf, which is usually in nearly complete darkness.
Several expeditions have made surveys of the same sites in previous years, which allows scientific comparisons to be made of any changes.
Life in the deep
The animal life on the sea floor is sparse because the regions under the ice shelf are very low in food sources, especially the phytoplankton and other biological material that rains down as “marine snow” in sunlit parts of the ocean.
Although the depth is only about 20 meters (18 feet) the animal species are similar to those found in the deepest parts of the open ocean, including sea cucumbers, deep sea sponges, sea stars and brittle stars.
Watching the locals
The scientists set up twenty “closed chamber” experiments on the sea floor to study the consumption of food by the few animals that live there.
Nutrients are relatively abundant this year because the ice shelf above the site was broken up during the Antarctic summer for two years in a row, which allowed more light to filter through.
Changes over time
Each closed-chamber experiment contained several seafloor animals in an enclosed space so their consumption of nutrients could be carefully measured over several days.
The results will be compared to similar studies made at the same site in 2009, when the sea-ice had not broken for several years and the seafloor ecosystem was relatively food-deprived as a result.
Life on the ice
Life for the expedition members above the ice includes making snow-mobile trips to a freshwater iceberg nearby to melt clean drinking water.
Ice from the floating ice shelf itself is not fit for drinking because it is salty and dirty with blown silt.
Trouble with the wildlife
The many Weddell seals that inhabit the area can pose a problem for human divers, because they like to swim to the diving holes and remain there breathing for a while.
Since it can be difficult for human divers to use the holes that have been occupied by the large seals, several diving holes are cut at each diving location.
A brief visit
So far the expedition have met just one Adélie penguin, which passed through their campsite on the last day of their stay at New Harbour site.
“The penguin was probably feeling rather lost, away from its mates and far away from open water and food, and therefore heading straight for our camp and some human company,” the expedition members wrote in an update on their Facebook page, Science Under The Ice. “Then it continued on its way towards the open sea.”