Quantification of tectonic stress effects on seafloor methane seepage in the Arctic

The SEAMSTRESS project will investigate the effect of tectonic stress on seafloor seepage across the west-Svalbard continental margin. I hypothesize that tectonic stress from Arctic mid-ocean ridges, has a significant impact on the pressure field that determines long-term seafloor methane release at adjacent continental margins. I further question whether passive margins are really inactive zones. Four cross-disciplinary experiments (seismological, geomechanical, 3D seismic and petrophysical) are designed to constrain critical parameterization of stress, sediment properties and fluid pressure to build a field-validated model of seafloor methane release coupled to regional stress variations. Regional stresses will be calculated in-situ integrating geothecnical measurements from 30 m long calypso core samples and micro-seismicity records from ocean bottom seismometers (OBS). High resolution 3D seismic data will be used to characterize faults and fractures to infer deformation style and orientation of principal stresses. Additional petrophysical parameters will be necessary to constrain numerical models that will allow to reconstruct and predict seepage in response to stress field variations. The ERC panel evaluated my hypothesis as relevant for advancing in our understanding of the interaction between carbon sources from marine sediments, the oceans, and global climate through geological time. Similarly, the panel pointed out the importance of my proposal for addressing deformation in passive margins, a problem that is often ignored. Main concerns raised are related to risks in the proposed methodology: 1) the likelihood of recording in-situ seismicity by the OBS network during the time of the experiment has to be better assessed; 2) the risks in the approach for reconstructing in-situ stress/strain from geotechnical samples of the shallow sediments and its relation to the regional stress regime have to be better evaluated.