The Arctic ice pack is a natural wonder. Observations over the past decades show that is drastically shrinking and in our lifetime it may disappear for parts of the year. We are privileged to have seen it now.
Text and images: Mauro Pau, researcher CAGE.
A storm from the south will hit us on our way back to Tromsø. The captain decides therefore to start our way out of the sea ice. Better not be here when the strong southerly winds will blow, compacting the sea-ice cover. As a consequence, the acoustic team has to come up with a new surveying plan suiting the new situation.
The most appealing scientific problem in the vicinity lies at 3000 m water depth on the northern flank of the East Greenland Ridge, a topographic high that originated during the opening of this part of the Atlantic Ocean. The ridge has been deflecting deep ocean currents ever since, and while doing so the currents weakened and lost their sediment load. The resulting contourite deposits, as they are called, could potentially reveal information on the temporal variability of the thermohaline ocean circulation, which redistributes heat around the globe.
We carry out our measurement and sampling program at three stations, this time deploying also the heat-flow probe at the deepest of the stations (3100 m). It takes about one hour to lower each piece of equipment to the seabed, and another hour is needed to bring it back on board. This means that we spend the whole day surveying the area. Once we are done, it is time to start our journey back to mainland Norway.
Steaming across a moonlit ocean, the captain manages to avoid the storm and brings us safely to the northernmost coast of Finnmark, near North Cape. Life onboard goes on with some work in the labs, cleaning duties, chatting in the day room, and the usual meal times. Passing from 78 to 72 degrees of latitude has remarkable effects: now there is light in the sky around mid-noon, and the frozen sea spray on deck is thawing!
We pass North Cape at 3:00 AM, and just over two hours later we reach the first sampling station. We then proceed to survey and sample the interior of Tanafjorden.
At 10:00 AM we start our journey to Tromsø. The expected storm has arrived, but we are navigating safely through the spectacular fjords of northern Norway. We will arrive in Tromsø tomorrow morning.
Despite the odds, we can be happy with what we have achieved. The quantity of the data is not abundant, but we did collect great quality data in a sea-ice setting in a time of the year polar expeditions are, to say the least, not common. We have pushed the limits of what R/V Kronprins Haakon can do, and have acquired fabulous experience.
The Arctic ice pack is a natural wonder. Observations over the past decades show that is drastically shrinking and in our lifetime it may disappear for parts of the year. We are privileged to have seen it now. At least some of us got deeply fascinated by that extreme environment, so much so that from the moment we left the sea ice we felt the urge to go back: there where even liquid seawater is below zero degrees Celsius, where an immense table of frozen ocean surrounds you, the night is several months long, and polar bears roam, sometimes under the northern light.