ALKOR AL575

This cruise is fully embedded in the project GEOSTOR (proposed in the framework of the DAM mission “Marine Carbon Sinks in Decarbonization Pathways”), where it will contribute to the assessment of mechanisms and potential risk of CO2 leakage along boreholes drilled through the sedimentary overburden above subseafloor storage formations in the North Sea. Biogeochemical and oceanographic baseline data at the study areas in the German sector of the North Sea will be collected that are necessary to discriminate potential leakage incidents from the natural variability of benthic COfluxes. In addition, during dedicated ROV dives gas releases will be quantified at
selected abandoned wells that were discovered on previous cruises (and possibly new detections on this cruise). This will enlarge the currently small existing dataset on methane emissions at abandoned wells in the North Sea.