Researcher
Sebastiaan J. van de Velde
- Research Expertise (University of Antwerp):Focussing on the biogeochemical cycles of carbon, iron and sulfur, I study the past and present ocean, using a research approach that combines field work and laboratory incubations with numerical modeling at the local, regional and global scales. Specific topics are the importance of burrowing fauna for cycling of carbon, iron and sulfur in the Earth System, spatial patterns of redox conditions and nutrient availability in low-oxygen oceans, and the impact of anthropogenic sediment disturbances on the coastal carbon cycle. Through this work I aim to improve our understanding of the Earth’s evolution and to provide new insights into the links between life and its geochemical environment.
- Research Expertise
(Vrije Universiteit Brussel):
Measurement of microniches in marine sediment environment
My first encounter with research was during my master thesis project. During this year I tried to develop a reliable method to detect microniches in marine sediments. Microniches being small (<1mm) structures where elements like sulfide, iron ... are found in higher concentrations as the immediate environment. Together with my promotors (Yue Gao and Willy Baeyens) I managed to use Diffusive Gradients in Thin Films (DGT) in combination with Laser Ablation Inductively Couple Plasma Mass Spectrometry to simultaneously detect sulfide and trace metal hotspots, leading to a publication in TrAC (Gao et al., 2015).
Electricity in the Seafloor
After my master thesis, I immediately continued with a PhD project under the guidance of Filip Meysman and Yue Gao. This thesis focuses on the effect of cable bacteria on geochemical redox cycling in marine sediments. These bacteria form long cables (hence the name) up to 7cm in the upper layers of the sediment, and transport electrons from the deeper, sulfide rich layers to the upper, oxygen rich zone. This electron transport (i.e. electrical current) turns the whole seafloor in a battery and has a major impact on the geochemistry.
- Keywords (University of Antwerp):EXPERIMENTAL STUDY, ECOSYSTEM FUNCTION, THEORETICAL STUDY, Biology
- Keywords (Vrije Universiteit Brussel):Chemistry (incl. biochemistry)
- Disciplines (University of Antwerp):Biogeochemistry, Inorganic geochemistry, Organic geochemistry, Chemical oceanography
- Research techniques (University of Antwerp):Chemical measurements, radio-isotope tracers, numerical modelling.
- Users of research expertise (University of Antwerp):policy, scientists, ...
- Users of research expertise
(Vrije Universiteit Brussel):
Measurement of microniches in marine sediment environment
My first encounter with research was during my master thesis project. During this year I tried to develop a reliable method to detect microniches in marine sediments. Microniches being small (<1mm) structures where elements like sulfide, iron ... are found in higher concentrations as the immediate environment. Together with my promotors (Yue Gao and Willy Baeyens) I managed to use Diffusive Gradients in Thin Films (DGT) in combination with Laser Ablation Inductively Couple Plasma Mass Spectrometry to simultaneously detect sulfide and trace metal hotspots, leading to a publication in TrAC (Gao et al., 2015).
Electricity in the Seafloor
After my master thesis, I immediately continued with a PhD project under the guidance of Filip Meysman and Yue Gao. This thesis focuses on the effect of cable bacteria on geochemical redox cycling in marine sediments. These bacteria form long cables (hence the name) up to 7cm in the upper layers of the sediment, and transport electrons from the deeper, sulfide rich layers to the upper, oxygen rich zone. This electron transport (i.e. electrical current) turns the whole seafloor in a battery and has a major impact on the geochemistry.