GoNorth - Geosciences in the Northern Arctic

Norway's outer border north of Svalbard runs across deep sea flats in the Nansen Basin and onto the southern flank of the Gakkel ridge. Fridtjof Nansen (1861-1930) discovered the mountain ridge when he drifted across the Arctic Ocean with Fram and probed the sea depth along the way. Well 130 years later, we know that this is the northernmost part of a 65,000 km long mountain ridge that stretches from the Arctic Ocean through the Norwegian Sea and the Atlantic Ocean, further through the Indian Ocean to the Pacific Ocean. The seabed forms along this mountain ridge at a rate from approximately 1 centimetre at the Gakkel Ridge to over 10 centimetres in the Pacific Ocean. The Gakkel ridge is not just a geographical end for the global Mediterranean ridge; it is also a geodynamic terminus for the Earth's system of spreading ridges. The Gakkel Ridge, as well as the parts of the spreading ridge that extends through the Fram Strait, have largely been inaccessible for research due to drift ice, but the research vessel Crown Prince Haakon has opened new opportunities to explore this most inaccessible part of the global ridge system. This advanced vessel is very well suited for use by the remotely controlled underwater vehicle Ægir 6000. Gakkelryggen was identified early on as a target for GoNorth. It also became clear early on that an expedition to the Gakkelridge should ideally be carried out as a two-ship operation (a tandem voyage), and a collaboration with the Alfred Wegner Institute (AWI) on joint operations with Crown Prince Haakon and Polarstern started early. Despite detailed plans, the drift ice took control, as it did for the Fram expedition and many later Arctic expeditions. Neither Polarstern nor Crown Prince Haakon were able to reach the main areas for the investigations. We still managed to carry out critical investigations along the westernmost part of the Gakkel Ridge, where a volcanic area and a hydrothermal field were mapped and visited by underwater craft. The deployment of oceanographic rigs had to be postponed until a later voyage, while other parts of the plans were carried out as far as conditions permitted. It was possible to carry out ice studies using instruments on board and at stations on the ice. Samples of seabed sediments were also taken for various purposes, and an oceanographic section was carried out across the Fram Strait. When we pulled south and out of the most difficult ice to investigate the 'Lucky Ridge' and the continuation of the Gakkelryggen through the Fram Strait, luck finally turned. With the help of a skilled crew and outstanding ROV pilots, we discovered a unique hydrothermal field 3,000 meters below the sea ice. Jubilant scientists transmitted Ægir 6000 video of magical mineral formations and an oasis of life. We gave the heat source the mythical name 'Ultima Thule' - a place to the north, beyond the borders of the world.

På toktet i 2023 gjorde forskerne et oppsiktsvekkende funn. Mellom Grønland og Svalbard oppdaget de et nytt hydrotermisk felt. Et hydrotermisk felt er et område på havbunnen med varmekilder hvor det er omfattende utfelling av mineraler. Feltet er et av de største hydrotermiske felter man pt. kjenner til. Feltet kan hjelpe til med å forstå etableringen av liv på jorden, fordi det er noe av det lengste man kan komme tilbake i historien og se hvordan livet på jorden oppstod den gang. Verdiene til feltets mineraler er heller ikke anslått. Funnet ble gjort på Lucky Ridge, et 1600 meter høyt undervannsfjell (samme høyde som Trollveggen), som ligger i en 4000 meter dyp dal. Ægir 6000 (Remotely Operated Vehicle, ROV) ble brukt til den operasjonen spesifikt og under dette toktet ble første gang operert under tunge isforhold.