The Under the Pole II expedition had a number of objectives. Above all, its vocation is to be a witness to the climate change underway, the local issues, and the challenges society will have to face in the years to come. From a scientific perspective, the priorities are to identify and catalogue the biodiversity that lies under the polar waters, study the interactions between the atmosphere, the ice sheet, and the ocean during an annual arctic cycle, and to explore the physiology of divers exposed to extreme cold.
divers and scientists
of the dives in unexplored regions
In addition to a financial endowment over two years, the Air Liquide Foundationsupplied Under the Pole II with equipment as well as the gases used for diving and oxygen therapy kits. Some sixty cylinders of oxygen and helium were delivered when the boat set sail from Brittany and others were shipped to Greenland, with the help of Air Liquide Denmark. With 300 dives under their belt, including 40 in the 100-meter zone, the need for these gases were significant.
The Air Liquide Foundation is particularly involved in supporting the two environmental and respiratory research programs.
Under the Pole II attempted to measure quantities of carbon dioxide (CO2) trapped in the ocean depths. When they form, polar ice sheets trap carbon dioxide and oxygen. These gases accumulate in pockets of brine (sea water with a high concentration of salt). Due to their greater density, these pockets sink, taking the trapped gases with them to the ocean depths. Consequently, the polar ice cap seems to play a key role in climate regulation. If it melts rapidly, this could have a profound impact on the future evolution of the earth’s climate.
One of the goals of Under the Pole II was to push back the limits of deep sea diving in arctic latitudes. This was a real challenge for Ghislain Bardout, expedition leader, and Martin Mellet, his dive buddy, who were surrounded by an entire team. And in April 2015, they scored a world first, descending to -111 meters under the polar ice cap, where the water temperature was -1.5°.
Diving into such deep waters is both a technical feat and a physiological one. In terms of equipment, there is simply no room for improvisation. In addition to heated wetsuits, divers wear a waterproof wetsuit that is adapted to very cold temperatures. As for the scuba equipment, divers use electronic rebreathers that work with a mix of three gases (nitrogen, oxygen and helium). In addition to increasing their autonomy considerably, their use offers added safety, optimizes decompression, and eliminates narcosis, which is sometimes called "the rapture of the deep".
Technical and demanding, these dives require extensive training, well-oiled routines, perfect communication between dive teammates, and total concentration. The descent takes about 5 minutes, while the autonomy is 10 minutes at a depth of 100 meters. On the other hand, it takes anywhere from 90 to 120 minutes to resurface, depending on how long it takes to complete the vital safety stops in the decompression process.
Numerous physiological measurements are taken from divers and analyzed to track the human body’s tolerance in an extreme environment (extreme undersea depth and very cold water).
Among the 500 measures taken, 5 areas of observation emerge:
To learn more about the work of Under the Pole II, visit the official website of the expedition!
Article published on November 08, 2017