Atlantic Ocean Tunnel Atlantic Ocean Tunnel The Atlantic Ocean Tunnel () is an undersea tunnel that is part of Norwegian County Road 64 which connects Kristiansund Municipality to Averøy Municipality in Møre og Romsdal county, Norway. The eastern end of the tunnel is on Kirkelandet island in the town of Kristiansund and the western end of the tunnel is on the island of Averøya, just west of the village of Sveggen. The long tunnel runs beneath the Bremsnesfjorden, reaching a depth of , making it one of the deepest undersea tunnels in the world. Construction began in 2006, and the tunnel opened on
Canfield ocean during the Great Oxygenation Event. The presence of oxygen in the deep ocean made the formation of BIF impossible, which is seen in ocean sediment records. Conversely, the Canfield Ocean theory postulates that deep ocean water remained anoxic long after the Great Oxidation Event, and he argued that the euxinic conditions in the deep ocean ceased the deposition of BIF in ocean sediments. Euxinic describes anoxic conditions in the presence of hydrogen sulfide. Euxinic ocean conditions, a term describing restricted hydrologic circulation that lead to stagnant or anaerobic conditions, are the likely factor leading to sulfidic oceans. Canfield ocean The