Abstracts are provided in the language submitted.

Introduction The Solid Carbon Project is an offshore negative emissions technology that involves injecting CO2 into sub seafloor basalt. Geological storage of CO2 in the pore space of basalt rocks is considered one of the most durable forms of CO2 sequestration in the world, as injected CO2 will mineralize and turn into carbonate rock. Offshore basalts, most commonly found as oceanic crust formed at mid-ocean ridges, are estimated to offer an almost unlimited reservoir. This helps to reduce atmospheric CO2 concentrations. Such subsurface related activities involving fluid injection can potentially change the pore pressure and effective stresses causing fault reactivation that may lead to induced seismicity. Methods In this preliminary study, part of the planned monitoring system is focused on induced seismicity and assessing the potential earthquake risk from CO2 injection. The risk assessment involves site characterization and modelling using a geomechanical analysis to understand the potential reactivation of faults. This included the effects of pore pressure increases from injection and the spatial and temporal relationships between injection and optimally oriented, critically stressed faults. Results The key findings shows that the risk is very low or almost zero for the injection rate and pressures for the proposed project. In order to ensure the modelling is correct, a proper monitoring system will be in place for continuous characterization and pressure management. Conclusion We can avoid injection into potentially active faults which will help reduce the risk of induced seismicity and ensure the safety of this climate solution.

Dr. Eneanwan Johnson