Cobalt-rich crusts on seamounts in Norwegian waters may represent a valuable and strategically important resource for the EU.
Centre for Deep Sea Research have conducted several cruises in the Norwegian Sea to investigate the resources and the fauna of the deep sea. Photo: Jebsen Center for Deep Sea Research (now Centre for Deep Sea Research)
– In just a small part of an area in the Norwegian Sea, we can potentially have cobalt resources equivalent to 20 times the EU’s annual needs, said Rolf Birger Pedersen, head of the Center for Deep Sea Research at the University of Bergen (UiB).
Pedersen gave a presentation during the conference NCS Exploration – Deep Sea Minerals in Bergen on 20 October.
Cobalt is an important ingredient in the green shift, and the metals is mainly used in the production of batteries. The International Energy Agency has announced that the demand for cobalt will increase significantly as the world’s car fleet is gradually being electrified.
In 2020, the European Commission published a report with a list of 30 critical minerals based on economic importance and supply risk. Cobalt is one of these.
In addition, manganese is monitored, a metal that is currently not on the list, but which is close to meeting the requirements. The crusts in Norwegian waters, as crusts in general, have high manganese contents and are often referred to as manganese crusts.
However, at this point the center manager’s calculation is only a rough estimate. Much more mapping is required to fully understand how large mineral resources we have on the Norwegian seabed, and how many of these – if anything – are economically viable.
The many surveys carried out by UiB and the Norwegian Petroleum Directorate so far indicates a huge potential, not only for cobalt, but also for a number of other minerals that the green shift requires (such as copper, nickel, lithium, zinc and rare earth metals).
Rolf Birger Pedersen is the head of the Centre for Deep Sea Research and professor at the Department of Earth Science at the UiB. Photo: Centre for Deep Sea Research
High-grade ore at the Mohn’s Ridge
Pedersen’s estimate was based on crust deposits along a small, selected part of the Mohn’s Ridge, located midway between Norway and Greenland.
– Along the flanks of the north-western part of the Mohn’s Ridge, the crusts are generally relatively thick, and 10 per cent of the area has slopes of at least 20 °. Given an average crust thickness of 15 centimeters in 5 percent of the area, we potentially have 1,000 million tonnes of ore.
– With an estimated average content of 0.42 percent cobalt, this gives 420,000 tonnes of cobalt, which currently corresponds to 20 times the annual EU demand.
The center manager emphasized that this constitutes a large area – 800 km2, corresponding to Kongsberg municipality, and it is uncertain whether this can be utilized with an acceptable impact on ecosystems.
– Both economic and environmental studies are needed on these deposits. Can the resources be utilized in a sustainable way – we do not know yet.
The combined deposits in Norwegian waters are far larger than the crusts on the northwestern part of the Mohn’s Ridge and also include so-called seafloor massive sulphides (SMS).
Read more about SMS deposits here: The ore factories on the seabed
An ROV is about to cut a piece of the manganese crust in the Norwegian Sea during a 2019 research cruise. Photo: Jebsen Center for Deep Sea Research (now Centre for Deep Sea Research)
Formed over millions of years
– The crusts have been formed over a very long time, and typically grow by a few millimeters per million years. The growth takes place mainly in steep areas where the slope is exposed to seawater and not covered by sediments, Pedersen explained.
The metal content of the crusts will depend on several factors, including the chemical conditions in the ocean back in time. It is therefore important to map each crust occurrence by their own in terms of grades and thicknesses.
Pedersen said that surveys of the crusts at the Aegir Ridge between Norway and Iceland showed lower contents of cobalt (0.22% per cent), but with higher contents of rare earth metals.
In short, the crusts form along slopes where oxygen-poor, metal-rich seawater is mixed with oxygen-rich bottom currents. It is estimated that there may be 33,000 seamounts in the world.
The largest deposits are probably found in the Pacific Ocean 3,000 kilometers southeast of Japan in an area called the Prime Crust Zone (PCZ).
PCZ probably holds 57 percent of the world’s seamounts, which can be up to 150 million years old. The resource estimates are 7.5 billion tonnes of ore that contain 4 times more cobalt and 9 times more tellurium than known resources on land.
