New expedition: Field work at a depth of 3000 metres

The mapping and exploring have often been in cooperation with research institutions such as the University of Bergen (UiB) and UiT, the Arctic University of Norway.

In the late summer of 2024, geologist Stig-Morten Knutsen from NOD joined MARUM (Center for Marine Environmental Sciences at the University of Bremen) and embarked upon an expedition in northern waters.

Geologist Stig-Morten Knutsen on fieldwork in East Greenland. (Archive photo).

Research Expedition MSM 131:This is Stig-Morten Knutsen's story about the background for the expedition, what the researchers were studying and what they found:

Data is the foundation for knowledge, and new data can yield new knowledge. This is also the case for knowledge about the deep ocean areas on the expanded NCS that have been opened for seabed mineral activity.

The NCS is legally defined as the area from the territorial waters border at 12 nautical miles from shore to the outer boundaries of the shelf or the demarcation line agreed with another state. The continental shelf overlaps with the exclusive economic zone in the area extending out to 200 nautical miles.

Norwegian jurisdiction over the shelf outside 200 nautical miles is contingent on approval from the UN Commission on the Limits of the Continental Shelf. The Norwegian submission establishing the outer limits of the expanded shelf was originally approved in 2009. At this point, 235,000 square kilometres outside the exclusive economic zone were added to the NCS in the Norwegian Sea, Barents Sea and Arctic Ocean.

If you're going to work on natural resources, it pays to have worked with nature. After all, nature defines and provides the resources – for example oil, gas or minerals. Several of us have been lucky enough to take part in geological field work to map, acquire data and better understand the development and dimensions of structures and reservoirs. This allows us to improve our skills in discovering, developing and managing petroleum resources.

Discovery of the hydrothermal field called Jøtul

Many of the principles of field-work in petroleum geology also apply for minerals – or seabed minerals for those of us in the Norwegian Offshore Directorate. Seabed mapping expeditions of resources and the environments serve many of the same objectives as field work onshore.

In 2022, MARUM, with participation from the Norwegian Offshore Directorate, conducted a four-week scientific expedition where a new hydrothermal vent and associated sulphides/metals was discovered in the northern part of the NCS. The discovery was made in an area west of Longyearbyen, and the field was named Jøtul.

Fenris is one of four active hydrothermal vents on the Jøtul field. The black water maintains a temperature of more than 300 degrees Celsius and contains metals and minerals that precipitate on the seabed. (Photo: MARUM)

Underwater hydrothermal vents are mineral-rich warm saltwater and gases flowing from fissures in volcanic areas on the seabed in the mid-ocean ridge area between tectonic plates. Conditions are extreme, devoid of light, and feature high pressure and high or low temperature.

New expedition with MARUM

In 2024, MARUM was headed back to the Jøtul field, and the expedition started on 17 August in Reykjavik. After picking up a new crew and team of researchers on Iceland, we set course northwards toward the Fram Strait between Svalbard and Greenland. A total of about 50 people were on board – split 50/50 between crew and researchers; most were from Germany, some were from Portugal, Greece, India and Peru – along with one from Norway and the Norwegian Offshore Directorate.

Once at Jøtul, we started to retrieve 15 OBS (ocean bottom seismometer) units. These are listening-systems that had been deployed on the seabed for about one year to register movements in the Earth's crust, for example minor earthquakes, which are common along the spreading ridge where Jøtul is located. By studying these movements, one can gain a better understanding of large-scale developments in the area – which in turn can tell  how Jøtul developed, and perhaps which metals and minerals could be found here.

The most important tool we had for exploration and mapping was an ROV (remotely operated underwater vehicle), which collected various samples, took photos, recorded video and was able to conduct a thorough survey of the seabed.

Here is a film showing the boat, the ROV and some of what we found on the seabed.

Several detailed photo mosaics were taken, which in turn are used to create 3D models of smokers and sulphide fields, and a number of rock samples were collected for further analysis.

Gyme is another vent on Jøtul from which warm water is flowing, and where such smokers will develop. This one is about 1.5 to 2 metres tall. (Photo: MARUM)

Fruitful scientific discussions

As is the case within petroleum, Germany has strong academic communities in geochemistry, and the same is true for geochemical analyses related to hydrothermal vents and oceanography (link).

Among other things, many  CTDs (conductivity, temperature and depth) were acquired. This is a system that measures physical, chemical and biological characteristics in the water/water column, as well as KIPS (Kiel Pumping System).

Similar to petroleum systems, geochemistry can be used in seabed mineral surveys to investigate the resources' origins, composition and potential sources – meaning the sulphides/minerals.

On days when the weather – more specifically wave heights – made it impossible to launch the ROV, we acquired large volumes of seabed and sediment samples. Overall, we collected around 35 stations in a grid across the Jøtul field. This means that Jøtul can provide a good indication of and expectation for how sediments, geology and not least the biology can develop in this type of hydrothermal field.

On Yggdrasil, the warm water forms large flanges several metres long, and on their underside, the warm stream of water creates a "mirror effect" when it flows out. (Photo: MARUM)

In deep water

This expedition included biologists from UiB and UiT, and we collected samples of sponges, foraminifera and tube worms. It will also be important to investigate the distribution of different species present  in the samples, and to further improve the biological characteristics of hydrothermal fields, both active and inactive parts.

In addition to detailed mapping on the Jøtul field, we had two trips to , the deepest point on the NCS (5569 metres), northwest of Spitsbergen. We came there to have the ROV dive on a – meaning frozen gas inside crystals in the seabed sediments. This was another opportunity for a photo mosaic. Also here we collected a range of  geological and geochemical samples.

Gas hydrates and bacterial matter have created a fascinating landscape on the seabed in the Molloy Deep. (Photo: MARUM)

Field work on Spitsbergen or Greenland, or in this instance, between the two islands, is multifaceted, even in addition to the professional aspects. : such an expedition can only be conducted if you're familiar with and can place your trust in the equipment you're using. Not least, you also need to trust your colleagues and the well-functioning community you've built on board. This was absolutely the case on Maria S. Merian. In addition to acquiring data and the new mapping, we had several professional discussions and presentations.

Five weeks is no short stint. The sea was rough, and we were far from shore. I embarked on this expedition in the summer, when leaves were still green. When I disembarked, it was autumn, and the colours had shifted to yellows, reds and other magnificent hues. We saw a lot of blue-grey skies and seas during the expedition, so I was more than pleased to see a broader palette when I came ashore!