Subsurface evidence for potentially seismogenic structures in the offshore Grand Banks region of Newfoundland, eastern Canada: present-day reactivation of inherited passive margin structures

Earthquakes in the offshore Grand Banks region of Newfoundland pose a risk to lives and property in nearby coastal communities and to crucial commercial infrastructure and operations in offshore areas. The 1929 M7.2 Grand Banks earthquake, which was associated with a tsunamigenic landslide, devastated the coastal communities in southern Newfoundland and ruptured several trans-Atlantic telecommunications cables. Despite this event, we still know little about the structural setting and neotectonics of the area. In this study, we identified potentially active tectonic structures, and associated secondary deformation features, affecting the youngest strata and the seabed in this region through the interpretation of offshore two-dimensional (2D) seismic reflection profiles. Analysis of these profiles also allowed us to interpret the relationship of the younger, potentially seismogenic structures to inherited passive margin structures at depth. Our findings on the locations and geometries of potentially active faults can be utilized as a basis for seismic hazard inputs for the modelling of earthquake scenarios, which are useful for estimating the potential impacts of the rupture of faults/fault segments on certain populations and assets.