POS518: Environmental baselines in the North Sea

29 September – 27 October 2017

The German research vessel RV Poseidon is currently on expedition in the North Sea, where the international team of scientists on board are using a range of instruments and techniques to measure environmental conditions at the seafloor and in the water column. The purpose of this is to establish the baseline environmental conditions in the area surrounding the location of the STEMM-CCS controlled release experiment that will take place in 2019. Establishing a good environmental baseline ahead of the experiment is essential to being able to detect anomalies or departures from ‘normal’ background conditions when the experiment is up and running.

The key scientific aims of expedition POS518 are:

  1. Pre-define and measure sensitive and robustly measurable environmental background variables, which are also indicative for subsea CO2 leakage, prior to offshore CO2 storage operations.
  2. Provide water column measurements of trace gases, nutrients, and carbonate chemistry variables to assess baseline conditions in the study region. Collect geochemical porewater data to provide a quantitative, process-based interpretation of porewater and benthic fluxes by state-of-the-art numerical model, collected under natural (baseline) conditions. The baseline data is also needed for comparison with data obtained during artificial CO2-release experiments, which will be conducted in the same area.
  3. Test newly-designed benthic chambers, novel chemical sensors, and hydroacoustic detection systems for measuring benthic and pelagic carbon fluxes (i.e. by using lab-on-the-chip technology, optodes, membrane inlet mass spectrometry, 3D-visual bubble imaging, and (multibeam) echosounder quantification.

The team on board RV Poseidon are sending weekly updates of their progress: