The SEAGAS project achieved its objectives through planned activities, but also through actions to address challenges that arose while taking opportunities for innovation. The primary challenge to the work programme lay in the scheduling of a joint acquisition campaign, which required a separate application to the French oceanographic fleet. Exceeding contingency plans, two ship-time proposals were submitted and given priority scheduling, but neither could be scheduled during the project, even after a 1 year suspension to extend its end date. These French-Brazilian campaigns based on SEAGAS hypotheses will nonetheless take place after the end of project, to both the Nile and Amazon margins, ensuring its long-term impact. Deferment of the campaigns was accommodated by expanding other research activities, to incorporate an additional modelling method, a second Brazilian case study, and a broader collaborative network, all of which contributed to key results on gas hydrate dynamics. Numerical modeling of the gas hydrate stability zone was extended to inverse methods, resulting in quantitative estimates of subsurface temperature variations linked to heat and fluid flux. The Brazilian margin case study was enlarged from the original study area, the Rio Grande cone, to include a second gas hydrate province, the Amazon fan, taking advantage of confidential datasets that became available to the outgoing host after the submission of the SEAGAS project. The Amazon case study area brought multiple benefits, allowing collaborative multi-disciplinary analyses and interpretations of sample data from fluid vents that satisified the research and training activities intended for the joint acquisition campaign, and resulting in the first discoveries of gas hydrates, of seafloor fluid vents and of mud volcanoes on the equatorial Brazilian margin. Together with work on the Rio Grande cone, results from the Brazilian case study areas generated hypotheses on gas hydrate dynamics in relation to fluid migration and venting that were successfully applied to the Nile margin. These activities led to the identification in all three study areas of discrepancies between the predicted and observed base of the gas hydrate stability zone (GHSZ), indicative of spatial variations in subsurface temperatures linked to heat transfer by fluid flux. In effect, the base of the GHSZ is inferred to be ‘elevated’ by upward fluid flow over broad areas, which may include narrower seafloor vents. This is particularly clear on the Amazon fan, where the upward flux of gas-rich fluids from depth is spatially associated with subjacent thrust-faults, the activity of which is inferred to drive changes in the stability of gas hydrates and of fluid venting through time. On the Rio Grande cone and Nile fan, spatial variations in the depth of the base of the GHSZ and the distribution of fluid vents can also be interpreted in terms of changes in the rates and/or styles of fluid flux. These results were both tested and disseminated in presentations at national and international conferences in Brazil, the USA and Europe. The project also involved a range of activities to promote the MSCA, the researcher acted as a Marie Curie Ambassador via a range of public engagements in Brazil, including seminars and interviews, and collaboration with EURAXESS in the founding of a Brazil Chapter of the Marie Curie Alumni Association (MCAA).
