A revision of the Newfoundland Margin: new results from revisited legacy seismic datasets

Models of continental margins evolution are largely based on incomplete information, much of it built on research that is now >20 years old. Recent developments in parallel computing and novel geophysical approaches provide now the means to obtain a new look at the structure with radically superior resolution seismic models and a mathematically-robust analysis of the data uncertainty, that was formerly difficult, if not unfeasible, to achieve.

We focused on the Newfoundland margin and applied bleeding-edge methodologies to a high-quality dataset acquired in 2000. The SCREECH data includes three primary transects with coincident multichannel seismic reflection data acquired on a 6-km streamer and wide-angle data recorded by short-period OBS and OBH spaced at ~10-20 km. This dataset was processed >15 years ago with now outdated methodologies. This re-processing in an HPC environment provided the high-resolution images that are needed to fulfill the characterization of this margin.

In particular, we performed the join inversion of multichannel and wide-angle seismic data, which radically improved the resolution of the velocity model and allow to perform a Pre-Stack Depth Migration of the multichannel data. The higher resolution of these images allows to characterize the different crustal domains of the margin in detail, as well as the tectonic structure.

Our results support a more complex structure than previously suggested, with crustal characteristics that change over short distances. In addition, reprocessing of the MCS data allowed to a better understanding of the crustal structure, as the Moho is imaged for the first time along the necking domain. Altogether, these results provide the high-resolution images needed to understand the formation and evolution of the Newfoundland margin.

Comparison of these results on the Newfoundland margin with the most novelty data on the West Iberian margin, acquired during the cruises FRAME (2018) and ATLANTIS (2022) (PI: C. Ranero, streamer data and coincident closely-spaced OBS data), provides a unique opportunity to further understand the evolution of the North Atlantic opening.