From Delft to the Swedish fjords:
Deep-sea sediment plume survey
Researching deep-sea sediment plumes
Can you imagine an environment where it is completely dark, the temperature barely changes and the water pressure is hundreds of times higher than at the Earth's surface? A vast ocean floor, flat and empty like a desert, at a depth of almost five kilometres. Precisely because conditions in the deep sea have been extremely stable for thousands of years, life there is often very sensitive to changes in the environment.
Yet this ocean floor contains large quantities of metals such as nickel, copper and cobalt, raw materials that are important for batteries, wind turbines and other technologies needed for the energy transition. To extract these raw materials responsibly in the future, a good understanding of the impact on the deep-sea environment is essential. One of the main concerns here is the creation of sediment plumes: clouds of fine particles that spread through the water and can interact with vulnerable deep-sea ecosystems.
This research is being conducted in collaboration between TU Delft, Allseas, the University of Gothenburg and the Kristineberg Centre in Sweden. Thanks in part to support from KIVI, I was given the opportunity to spend a month doing research at the Kristineberg research station on the Swedish west coast.
Looking at suspended sediments with sound and light
My research focuses on using acoustic and optical sensors to measure properties of sediment plumes. Instead of analysing water samples manually, these sensors seek to provide real-time information on, for example, sediment concentrations and the size of suspended particles.
For this, I worked with different measurement tools, including acoustic backscatter sensors and optical turbidity sensors. These techniques measure how sound waves and light are scattered by suspended sediment particles in water. However, the behaviour of these sediments turns out to be surprisingly complex. The extremely fine clay particles can clump together to form larger aggregates, called flocs, whose properties change continuously due to flow, turbulence and salinity.
During my stay, I conducted many laboratory experiments to better understand how these sensors respond under different conditions. Besides performing the experiments, data analysis played an important role within the research. Although the results are currently undergoing further analysis, the initial observations provide promising insights for future monitoring techniques of deep-sea plumes.
Research among the fjords
Besides the technical research, the surroundings were also a special experience. I stayed in a student house right on the Swedish fjords, in the middle of nature. Outside the lab, I spent a lot of time hiking along the coast, rowing through the fjords and exploring Sweden's west coast.
The Kristineberg research station has a strong focus on marine and biological research, which introduced me to many other research fields as well. In my spare time, I regularly attended biological experiments on marine ecosystems. It was precisely this combination of technology, ecology and international cooperation that made this experience extra valuable to me and strengthened my motivation for better monitoring of deep-sea activities.
A look at the future of responsible deep-sea research
This research period not only taught me a lot technically about sensor technology, data processing and experimental research, but also showed how important international cooperation is in complex environmental issues.
I am very grateful to KIVI for making this experience possible. The combination of research, international cooperation and living by the Swedish fjords has further strengthened my interest in offshore technology and environmental monitoring. I look forward to elaborating on the results of this research in the coming period and contributing to the development of responsible deep-sea research.
