Testing of a new flexible monitoring tool for environmental parameters such as offshore gas concentrations, constructed and built within the framework of the German nationally-funded project "FlexMoT". For the testing of the first prototype, a strong sea floor source of methane is required. The well site 22/4b in the British EEZ is such a place with a permanent gas flow from the sea floor to the atmosphere. The well site 22/4b has been intensively studied by GEOMAR Helmholtz Centre for Ocean Research during previous research cruises with RV ALKOR. During cruise AL436 some short surveys with CTD/water sampler and deployments of the FlexMoT observation system and a small lander for control measurements are planned. No permanent deployments of instruments are intended.
The water column and seafloor in the vicinity of the outcropping gas flare will be monitored with single beam echo-sounder and TV-cameras mounted to a towed frame, respectively. Water samples will be obtained from Rosette water sampler profiles for methane measurements (headspace analysis). A small bottom lander will be deployed for the residence time of the vessel to measure currents and methane at the sediment water interface. The new environmental observation instrument (a bottom frame) will be deployed and the integrated water column module which profiles the water column measuring methane and CTD is tested. Some surficial sediment samples will be taken with a small multicorer.
Olaf Pfannkuche (GEOMAR Helmholtz Centre for Ocean Research, Kiel (East Shore Campus))
Around abandoned well location 22/4b (57.916N, 01.633E)